Dissertations / Theses on the topic 'Canopy cover'
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Noble, Sidney Lake. "The Influence of Canopy Cover and Canopy Heterogeneity on Plant Diversity within Oak Savannas." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1595843486558554.
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Cuello, Nerea. "NEW CONCEPT OF A STROLLER CANOPY." Thesis, Tekniska Högskolan, Jönköping University, JTH, Industridesign, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-49442.
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This master thesis report describes the process of designing, developing and building an accessory for a stroller that protects the kid from rain and sun. The project is a collaboration with Thule Sweden AB, in Hillerstorp.The work starts with developing a new concept idea for Thule’s category “Active with kids”, in the line of strollers, and with a focus on the Southern Europe market, more concretely Spain. The design proposal fits and expresses Thule’s vision and brand language.The project started with gaining knowledge about the market, investigating the user needs with surveys to find out the design goals. An iterative process of ideation, brainstorming and building mock-ups ended with a final concept that was going to be further developed. A full-scale model was built to test the idea from the functional and aesthetic perspective. The materials used were mainly fabrics, foam, zippers, thread and a lot of sewing.The result is a new stroller canopy for different weather conditions. It is well equipped to improve parents experience when going out for a ride with their child.It has to be mentioned that this master thesis research section was conducted in pairs, between Berta Cester and Nerea Cuello, and the rest of the phases was an individual work. As a result, two different products were produced for the same category, the stroller market.
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Malnou, Cathy. "A canopy approach to nitrogen recommendation for the sugar beet crop." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288992.
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Brinez, Carolina. "Dynamics of canopy cover in a wet forest in Costa Rica." FIU Digital Commons, 2005. http://digitalcommons.fiu.edu/etd/1884.
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I examined the effects of soil and slope conditions on canopy dynamics in terms of openness and leaf area index through time as measured by hemispherical photography. Specifically, I compared alluvial versus residual soil and slope versus plateau and flat plots in an old-growth tropical wet forest in Costa Rica. No significant effects of slope were found for any estimator of canopy coverage in any analysis. Soil type approached significance as a single factor and several soil*year interactions were highly significant. In addition, I found highly significant inter-annual variation in all analyses that was concordant on all plot types. This is the first long-term study to document substantial inter-annual variation in canopy cover for a tropical wet forest. These patterns are a combination of seasonal changes in leaf area, forest dynamics resulting from gap formation and closure, and inter-annual variation in leaf area coverage caused by climate variation.
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Berdie, Ian Joseph. "Assessing Canopy Cover Requirements of Storm's Stork (Ciconia stormi) at Multiple Scales." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_theses/132.
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Much conservation work focuses on individual species, partly because of the perception that wildlife species are effective symbols for raising funds and drawing awareness to environmental causes. However, for species-based studies to aid conservation efforts, the biological and ecological needs of species need to be addressed in a way that informs decisions and provides concrete recommendations for land managers. This thesis addresses the forest cover needs of Ciconia stormi, a rare and understudied bird species that inhabits the islands of Borneo and Sumatra and parts of peninsular Malaysia. Levels of forest canopy cover associated with areas inhabited by Ciconia stormi are identified at multiple spatial resolutions using a 500m MODIS soft classification product, 30m Landsat data, and hemispherical photographs. Important threshold values of 75 percent tree cover was identified at the regional scale, and 85 percent at foraging sites. There has been severe forest disturbance in regions inhabited by Ciconia stormi between 1993 and 2004, indicating the species may be somewhat tolerant to disturbance. Areas having been logged at least 20 years before present average over 85 percent canopy cover and have few large gaps, indicating that these forests may be suitable habitat for the species.
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Goff, Bruce Franklin. "Dynamics of canopy structure and soil surface cover in a semiarid grassland." Thesis, The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_503_sip1_w.pdf&type=application/pdf.
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Kang, Katherina A. "Soil Carbon Accumulation in an Urban Ecosystem: Canopy Cover and Management Effects." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703418/.
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Black carbon (BC), a stable form of organic carbon (OC), is a byproduct of the incomplete combustion of biomass, biofuels, and fossil fuel. The main objectives of this research are to examine the spatial distribution of OC and BC in urban soil and determine the influence of tree canopy cover and landscape maintenance on soil carbon accumulation. Soil sampling was conducted at 29 sites throughout the City of Denton, Texas, in May 2019. Samples were collected from underneath post oak canopies and in adjacent open areas and were analyzed for total carbon (TC), total organic carbon (TOC), total N (TN), C:N ratio, and BC. Although maintenance levels had no significant effect, TOC was greater underneath trees (5.47%, 5.30 kg/m2) than lawns (3.58%, 4.84 kg/m2) at the surface 0-10 cm. Total nitrogen concentration was also greater underneath trees (0.43%) than lawns (0.31%) at the surface 0-10 cm. Preliminary results for BC were closely correlated to TOC. The lack of difference in C:N ratio between cover types indicates that leaf litter quality may not be the primary driving factor in soil C and N accumulation. Instead, differences in soil properties may be best explained by manual C inputs and greater atmospheric deposition of C and N to soils with tree canopy cover. Identifying patterns and potential drivers of soil OC and BC accumulation is important because soil carbon sequestration not only reduces atmospheric CO2, but also may provide additional pollution mitigation benefits, thereby contributing to a more sustainable urban environment.
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Kimball, Pulelehua L. "Urban Tree Canopy Assessments in the Chesapeake Bay Watershed." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/48057.
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An urban tree canopy assessment (UTCA) is a new technology that can inform management decisions to optimize the economic, social and environmental benefits provided by urban forests. A UTCA uses remote sensing to create a comprehensive spatial snapshot of a locality's land cover, classified at a very fine scale (1 meter or less). Over the past decade, UTCAs have been conducted for numerous localities in the Chesapeake Bay watershed (CBW) as part of a strategy to enhance urban tree canopy (UTC) and reduce stormwater runoff that pollutes the Chesapeake Bay. Our research examined how local governments employ these UTCAs and identified barriers to and drivers of UTCA use for urban forest planning and management. We conducted a web-based survey of all localities in the CBW with populations over 2,500 for which a UTCA existed as of May 2013. We found that 33% of respondents reported being unaware that a UTCA existed for their locality. Even so, survey results showed that localities aware of their UTCA were using it to establish UTC goals, create and implement strategies to achieve those goals, and monitoring progress towards UTC goals. Survey localities were segmented based on how they reported using their UTCA to provide insight on possible outreach and technical assistance strategies that might improve future UTCA use. Overall, we found that larger localities with more developed urban forestry programs use their UTCA more frequently. However, we found several exceptions, suggesting that UTCAs could be an important catalyst for expanding municipal urban forestry programs.Master of Science
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Gaulton, Rachel. "Remote sensing for continuous cover forestry : quantifying spatial structure and canopy gap distribution." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3419.
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The conversion of UK even-aged conifer plantations to continuous cover forestry (CCF), a form of forest management that maintains forest cover over time and avoids clear-cutting, requires more frequent and spatially explicit monitoring of forest structure than traditional systems. Key aims of CCF management are to increase the spatial heterogeneity of forest stands and to make increased use of natural regeneration, but judging success in meeting these objectives and allowing an adaptive approach to management requires information on spatial structure at a within-stand scale. Airborne remote sensing provides an alternative approach to field survey and has potential to meet these monitoring needs over large areas. An integral part of CCF is the creation of canopy gaps, allowing regeneration by increasing understorey light levels. This study examined the use of airborne lidar and passive optical data for the identification and characterisation of canopy gaps within UK Sitka spruce (Picea sitchensis) plantations. The potential for using the distribution of canopy and gaps within a stand to quantify spatial heterogeneity and allow the detection of changes in spatial structure, between stands and over time, was assessed. Detailed field surveys of six study plots, located in three UK spruce plantations, allowed assessment of the accuracy of gap delineation from remotely sensed data. Airborne data (multispectral, hyperspectral and lidar) were acquired for all sites. A novel approach to the delineation of gaps from lidar data was developed, delineating gaps directly from the lidar point cloud, avoiding the interpolation errors (and associated under-estimation of gap area) resulting from conversion to a canopy height model. This method resulted in improved accuracy of delineation compared to past techniques (overall accuracy of 78% compared to field gap delineations), especially when applied to lidar data collected at relatively low point densities. However, lidar data can be costly to acquire and provides little information about the presence of natural regeneration or other understorey vegetation within gaps. For these reasons, the potential of passive optical (and in particular, hyperspectral) data for gap delineation was also considered. The use of spectral indices, based on shortwave infrared reflectance or hyperspectral characteristics of the red- edge and chlorophyll absorption well, were shown to enhance the discrimination of canopy and gap and reduce the influence of illumination conditions. An average overall accuracy of 71% was obtained using hyperspectral characteristics for gap delineation, suggesting the use of optical data compares reasonably to results from lidar. Methods based on shortwave infrared (SWIR) reflectance were shown to be sensitive to within gap vegetation type, with SWIR reflectance being lower in the presence of natural regeneration. Potential for using optical data to classify within gap vegetation type was also demonstrated. Methods of quantifying spatial structure through the use of indices describing variations in gap size, shape and distribution were found to allow the detection of structural differences between stands and changes over time. Gap distribution based indices were also found to be strongly related to alternative methods based on relative tree positions, suggesting significant potential for consistent monitoring of structural changes during conversion of plantations to CCF. Remotely sensed delineations of canopy gap distribution may also allow spatially explicit modelling of understorey light conditions and potential for regeneration, providing further information to aid the effective management of CCF forests.
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Donaldson, Jason. "Do trees suppress grass fuel loads? : canopy cover effects in South African savannas." Bachelor's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/26376.
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Continental scale analysis of the savanna biome indicated that fire did not spread at tree canopy cover above 40%. This study investigates this relationship in a field study. It is possible that the type of tree (forest vs. savanna) may influence the amount of shade experienced by the understory and therefore this study also explores differences in LAI between congeneric pairs of forest and savanna tree species. Data were collected in two major South African savanna parks. Plots were set out to measure grass biomass in reference to canopy cover in both Kruger National Park (n=60) and the Hluhluwe-iMfolozi Game Reserve (n=82). Seven congeneric pairs were selected to compare leaf area and LAI between forest and savanna tree species using a destructive method. Against expectations, it was only when canopy cover reached 80% that grass fuel load was too low to support fire spread in all Kruger National Park plots (Pr=O) and 89% of the Hluhluwe-iMfolozi Game Reserve plots (Pr=0.11). No consistent, general relationships were evident with leaf area or LAI in comparisons between forest-savanna congeneric pairs. The significance of these findings and future direction is discussed.
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Lee, Alex C., and alexanderlee@aapt net au. "Utilising airborne scanning laser (LiDAR) to improve the assessment of Australian native forest structure." The Australian National University. Fenner School of Environment and Society, 2008. http://thesis.anu.edu.au./public/adt-ANU20090127.222600.
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Enhanced understanding of forest stocks and dynamics can be gained through improved forest measurement, which is required to assist with sustainable forest management decisions, meet Australian and international reporting needs, and improve research efforts to better respond to a changing climate. Integrated sampling schemes that utilise a multi-scale approach, with a range of data sourced from both field and remote sensing, have been identified as a way to generate the required forest information. Given the multi-scale approach proposed by these schemes, it is important to understand how scale potentially affects the interpretation and reporting of forest from a range of data.
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To provide improved forest assessment at a range of scales, this research has developed a strategy for facilitating tree and stand level retrieval of structural attributes within an integrated multi-scale analysis framework. The research investigated the use of fine-scale (~1m) airborne Light Detection and Ranging (LiDAR) data (1,125 ha in central Queensland, and 60,000 ha in NE Victoria) to calibrate other remotely sensed data at the two study sites. The strategy refines forest structure mapping through three-dimensional (3D) modelling combined with empirical relationships, allowing improved estimation of maximum and predominant height, as well as foliage and crown cover at multiple scales. Tree stems (including those in the sub-canopy) were located using a height scaled crown openness index (HSCOI), which integrated the 3D density of canopy elements within the vertical profile into a two-dimensional spatial layer. The HSCOI modelling also facilitated the reconstruction of the 3D distribution of foliage and branches (of varying size and orientation) within the forest volume.
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Comparisons between forests at the Queensland and NE Victorian study sites indicated that accurate and consistent retrieval of cover and height metrics could be achieved at multiple scales, with the algorithms applicable for semi-automated use in other forests with similar structure. This information has facilitated interpretation and evaluation of Landsat imagery and ICESat satellite laser data for forest height and canopy cover retrieval. The development of a forest cover translation matrix allows a range of data and metrics to be compared at the plot scale, and has initiated the development of continuous transfer functions between the metrics and datasets. These data have been used subsequently to support interpretation of SAR data, by providing valuable input to 2D and 3D radar simulation models. Scale effects have been identified as being significant enough to influence national forest class reporting in more heterogeneous forests, thus allowing the most appropriate use and integration of remote sensed data at a range of scales. An empirically based forest minimum mapping area of 1 ha for reporting is suggested. The research has concluded that LiDAR can provide calibration information just as detailed and possibly more accurately than field measurements for many required forest attributes. Therefore the use of LiDAR data offers a unique opportunity to bridge the gap between accurate field plot structural information and stand to landscape scale sampling, to provide enhanced forest assessment in Australia.
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Griffin, Alicia Marie Rutledge. "Using LiDAR and normalized difference vegetation index to remotely determine LAI and percent canopy cover at varying scales." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1117.
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Pavuluri, Kiran. "Winter Barley as a Commodity Cover Crop in the Mid-Atlantic Coastal Plain and Evaluation of Soft Red Winter Wheat Nitrogen Use Efficiency by Genotype, and its Prediction of Nitrogen Use Efficiency through Canopy Spectral Reflectance in the Eastern US." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47103.
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To understand the impact of N management on harvestable cover crop systems, seven research trials compared: 1) standard intensive management (SIM) (both fall and spring N application), 2) No fall N, a single spring N application, and 3) Cover N (no N application) effects on winter barley (Hordeum vulgare L.) plant biomass (PB), plant N uptake (PNU), grain yield, residual soil nitrate (RSN), and ammonium (RSA). In general, at winter dormancy, SIM resulted in increased PB and PNU but not RSN or RSA. At cover crop termination; SIM and the No fall N practices increased PNU, and at harvesting stage; they produced higher grain yields than the Cover N practice with little significant effect on RSN or RSA values, under normal climatic conditions. While overall yields for the No fall N treatment were lower (8%) than SIM yields, partial net return was similar due to decreased fertilizer input.
Nitrogen use efficiency (NUE) of soft red winter wheat (SRWW) can be improved by characterizing genotypes for NUE using canopy spectral reflectance [(CSR), a cheap, rapid and non-destructive remote sensing tool]. The other objectives of this study were to evaluate the predictive potential of vegetative reflection indices for wheat nitrogen use efficiency (NUE) by genotype and the appropriate stages of CSR sensing. An elite panel of 281 regionally developed SRWW genotypes was screened under low and normal N regimes in two crop seasons for grain yield, N uptake, nitrogen use efficiency for yield (NUEY) and nitrogen use efficiency for protein (NUEP). The best models incorporating CSR data at wheat heading explained a significant proportion of total variation in grain yield, N uptake, NUEY and NUEP. Based on the best linear unbiased predictor values, genotypes were ranked and grouped into quartiles and the most efficient and responsive genotypes were identified. A significant proportion of the genotypes with high NUEY under high N conditions also had high NUEY under N stress; however, this was not the case for NUEP. Similarly, a significant proportion of genotypes with high NUEY also had high NUEP under both normal and low N conditions.Ph. D.
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Gerner, Eden. "The Effects of Impervious Surface Area, Tree Canopy Cover, and Floral Richness on Bee Abundance, Richness, and Diversity Across an Urban Landscape." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41213.
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As urbanization increases globally, habitat loss is increasing at an unprecedented rate, eroding the suitability of many landscapes for most forms of wildlife, including bees. At least some of this habitat loss is through the ongoing expansion of urban areas, a process termed ‘urbanization’. Studies of the effects of urbanization and urban land use on bees have reported a mixture of results, including some instances where at least some species appear to do better in urban areas than they do in lands surrounding urban areas. While the impacts of urbanization on bee communities has been investigated, tree canopy cover has been largely overlooked as a contributor to urban bee distributions, despite their potential importance as a predictor of bee activity. I investigated the impacts of urban land use and tree canopy cover on bee communities across a variety of neighbourhoods in a medium-sized Canadian city (Ottawa, Ontario). In total, I surveyed bee communities in 27 residential yards that varied in terms of the degree of urban land use (measured as percent impervious surface area) and tree canopy cover (percent deciduous canopy cover) across a range of spatial scales. Using linear regression and model selection, I determined that bee abundance was negatively correlated with the degree of urban land use surrounding a yard, and positively correlated with the richness of the local (i.e., yard) flowering plant community. Yard floral richness, but not urban land use or tree cover, was also a predictor of the diversity of the bee community visiting the yard. In fact, tree canopy cover did not factor in any of the top models predicting either bee abundance, richness, or diversity. My results support the idea that urban land use could negatively impact bee communities, but also suggest that landscaping and urban planning decisions that maximize
local floral richness could counteract some of the negative impacts of urbanization on bee populations.
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McClelland, Rebecca Elizabeth Mooneyhan. "Ground Layer Response to Disturbance in the Pine-Dominated Eastern Foothill Region of West-Central Alberta, Canada." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/436.
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The canopy cover of the Pinus contorta forests of west-central Alberta, dictates colonization of the forest floor ground layer. This dynamic ground layer is a mosaic of feather mosses and reindeer lichens in a system driven by disturbance. In this project, anthropogenic was used to control canopy cover change and study its effects on the ground layer. Timber companies selectively mechanically thinned sections producing three experimental areas with uncut controls. Data were collected from 182, 6.5 m2 plots located in the four thinning areas. Six general areas of inquiry were posed around determining ground layer responses to canopy opening: 1) vegetation, 2) plant species richness, 3) plant abundance, 4) diaspore availability, 5) environmental limiting factors, 6) moss and lichen establishment. In 1997, three timber companies were involved in selective tree removal at three different stand percentages (20/40/60%), however, these were not consistent when measured in 2005. This variation in operational logging along with changes over the seven year time period, resulted in strong disparity for each of the thinning regimes. Percent canopy cover change for all thinned plots was ranked and three new groups created; least, moderate, most canopy change. These new groups formed the basis for the data presented in Chapter 3. The three thinning groups had little to no effect on species richness, but overall showed a small decrease from measurements taken pre-harvest. Numbers of locally rare species were similar to pre-harvest levels, but there were some gains and losses of species between pre-harvest and seven years post-harvest. In contrast to the lack of change in diversity, the abundance of dominant species and major vegetation components underwent dramatic changes. Dominant species of both vascular plants and bryophytes decreased with increasing canopy openness, with vascular plants being gradually affected while mosses were more affected at less intense canopy opening. Abundances of lichens showed no change. When measuring limiting factors (biotic and abiotic) for ground layer mosses and lichens, diaspores (spores and fragments) were plentiful in all stands, but differed in abundance at the micro-scale. The position of feather mosses and reindeer lichen in the forest floor mosaic appears to be due to an intermingling of environmental influences (at both the meso- and micro-scale). With less environmental constraints on lichens and the widespread availability of lichen fragments, lichens are more tolerant to the conditions evoked by thinning than are mosses. Mosses are more restricted by environmental conditions and have more constrained diaspore dispersal than lichens. Thus, mosses are more limited both by diaspore dispersal and by harsh environmental conditions in open canopy habitats. Whereas relative humidity (RH) did not differ at the stand level, moss dominated areas had higher RH no matter where they occurred, lichen-dominated areas did not--suggesting the moss occurrence is at least partially controlled by micro-scale level factors. Moss establishment is effected by the "ghosts" of past events and substrates. Mosses are widespread in formerly moss-dominated areas that contain organic substrates and high canopy cover. Lichen establishment is limited in previously moss-dominated areas. Species interactions weighed more heavily on moss establishment than on that of lichens. Therefore, the effects of canopy change on the ground layer are variable corresponding to moss decreases, but not lichens. Seven years post-harvest species diversity is unchanged, but vegetation, as a whole, has been affected.
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Roundy, Darrell B. "Estimating Pinyon and Juniper Cover Across Utah Using NAIP Imagery." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5575.
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Expansion of Pinus L. (pinyon) and Juniperus L. (juniper) (P-J) trees into sagebrush (Artemisia L.) steppe communities can lead to negative effects on hydrology, loss of wildlife habitat, and a decrease in desirable understory vegetation. Tree reduction treatments are often implemented to mitigate these negative effects. In order to prioritize and effectively plan these treatments, rapid, accurate, and inexpensive methods are needed to estimate tree canopy cover at the landscape scale. We used object based image analysis (OBIA) software (Feature AnalystTM for ArcMap 10.1®, ENVI Feature Extraction®, and Trimble eCognition Developer 8.2®) to extract tree canopy cover using NAIP (National Agricultural Imagery Program) imagery. We then compared our extractions with ground measured tree canopy cover (crown diameter and line point) on 309 subplots across 44 sites in Utah. Extraction methods did not consistently over- or under-estimate ground measured P-J canopy cover except where tree cover was > 45%. Estimates of tree canopy cover using OBIA techniques were strongly correlated with estimates using the crown diameter method (r = 0.93 for ENVI, 0.91 for Feature Analyst, and 0.92 for eCognition). Tree cover estimates using OBIA techniques had lower correlations with tree cover measurements using the line-point method (r = 0.85 for ENVI, 0.83 for Feature Analyst, and 0.83 for eCognition). Results from this study suggest that OBIA techniques may be used to extract P-J tree canopy cover accurately and inexpensively. All software packages accurately evaluated accurately extracted P-J canopy cover from NAIP imagery when imagery was not blurred and when P-J cover was not mixed with Amelanchier alnifolia (Utah serviceberry) and Quercus gambelii (Gambel's oak), which are shrubs with similar spectral values as P-J.
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Bopp, Jesse A. "Combined effects of water chemistry, canopy cover, and stream size on benthic macroinvertebrates along a central Appalachian stream continuum." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2474.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains viii, 96 p. : ill., maps (some col.). Includes abstract. Includes bibliographical references (p. 41-51).
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Almeida, Julio Augusto Pires 1958. "Use of infrared thermometry to measure canopy-air temperature difference at partial cover to assess crop water stress index." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/191890.
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A study on the potential for extracting canopy temperature from composite scenes of plant and soil background using infrared thermometry was carried out. Using field and laboratory data, Heilman's equation was tested for its sensitivity and ability to predict actual canopy temperature. Using Idso's approach, crop water stress index values were calculated for partial and full canopies. The study showed that under partial canopy situations calculated leaf temperature is very sensitive to soil background and composite scene temperatures and moderately sensitive to canopy emissivity and cover. Negative values as well as values greater than unity for crop water stress index were calculated for partial canopy conditions. Negative values were also reported for the full canopy cover conditions thus, establishing a need for better estimates of data used in calculation of crop water stress index values. Infrared thermometry does not show much promise as an irrigation scheduling technique for canopies under partial cover using the approach investigated in this study.
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Ramsey, Jeff. "Tree Canopy Cover and Potential in Portland, OR: A Spatial Analysis of the Urban Forest and Capacity for Growth." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/5110.
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Urban forests have positive impacts on human and ecosystem health, reduce stress on aging stormwater infrastructure, increase property values, and reduce energy consumption. The scale of these benefits ranges from the hyper-local to the global. While the benefits of urban forests can extend well beyond the boundaries of cities, they often do not reach all residents of the city equally. Urban forest policies do not adequately address environmental equity or employ planting strategies with knowledge of the social and political factors that determine the spatial variations of tree canopy extent in cities. Chapter I analyzes the determinants of current canopy extent in Portland, OR using spatial regression analysis. Chapter II uses current landcover datasets to identify potential planting opportunities. Results of spatial regression show that income and education level are significantly positively linked to tree canopy, while sewer pipe density, an indicator of development, is negatively associated with canopy. The majority of tree canopy and potential in the city occurs on private, residential lands. Distribution of canopy potential is not even, with greater amounts in north and outer east side areas. Findings presented here will inform efforts to expand tree canopy in Portland in a manner that is spatially explicit and based on Portland's unique demographics, land use assemblage, and development policies.
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Ritchie, Glen L. "Use of Ground-Based Canopy Reflectance to Determine Radiation Capture, Nitrogen and Water Status, and Final Yield in Wheat." DigitalCommons@USU, 2003. https://digitalcommons.usu.edu/etd/5632.
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Ground-based spectral imaging devices offer an important supplement to satellite imagery. Hand-held, ground-based sensors allow rapid, inexpensive measurements that are not affected by the earth’s atmosphere. They also provide a basis for high altitude spectral indices.
We quantified the spectral reflectance characteristics of hard red spring wheat (Triticum aestivum cv. Westbred 936) in research plots subjected to either nitrogen or water stress in a two year study. Both types of stress reduced ground cover, which was evaluated by digital photography and compared with ten spectral reflectance indices. On plots with a similar soil background, simple indices such as the normalized difference vegetation index, ratio vegetation index, and difference vegetation index were equal to or superior to more complex vegetation indices for predicting ground cover. Yield was estimated by integrating the normalized difference vegetation index over the growing season. The coefficient of determination (r2) between integrated normalized difference vegetation index and final yield was 0.86.
Unfortunately, none of these indices were able to differentiate between the intensity of green leaf color and ground cover fraction, and thus could not distinguish nitrogen from water stress. We developed a reflective index that can differentiate nitrogen and water stress over a wide range of ground cover. The index is based on the ratio of the green and red variants of the normalized difference vegetation index. The new index was able to distinguish nitrogen and water stress from satellite data using wavelengths less than 1000 nm. This index should be broadly applicable over a wide range of plant types and environments.
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Plenzler, Michael A. "Terrestrial Influences on the Macroinvertebrate Biodiversity of Temporary Wetlands." Bowling Green State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1355081524.
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Cadaret, Erik M. "Vegetation Canopy Cover Effects on Sediment and Salinity Loading in the Upper Colorado River Basin Mancos Shale Formation, Price, Utah." Thesis, University of Nevada, Reno, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10001481.
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With future climate change and increased water demand and scarcity in the Colorado River Basin, the Bureau of Reclamation estimates that the costs of salinity damage will increase for Colorado River users and will exacerbate the current salinity challenges. This study focuses on saline and sodic soils associated with the Mancos Shale formation in order to investigate the mechanisms driving sediment and salinity loads in the Price-San Rafael River Basin of the upper Colorado River. A Walnut Gulch rainfall simulator was operated with a variety of slope angles and rainfall intensities at two field sites (Price, Dry-X) near Price, Utah in order to evaluate how the amount and spatial distribution of vegetation affects salinity in runoff. For each simulated rainfall event, the time-varying concentrations of major cations, anions, and sediment in runoff were measured. Principal component analysis revealed that the two field sites are generally different in runoff water chemistry and soil chemistry, likely due to the difference in parent material and soil indicative of their location on different geologic members. The Dry-X site also has substantially greater total dissolved solids (TDS) and sediment in runoff, soil sodium absorption ratio (SAR), and soil cation exchange capacity (CEC) than the Price site. Despite these differences, a consistent positive linear relationship between the plot-averaged sediment and TDS concentration was found across both sites. The Rangeland Hydrology Erosion Model (RHEM) was calibrated to provide unbiased estimates of sediment in runoff from 23 runs of the rainfall simulator. RHEM simulated the plot-plot variability best at Dry-X compared to Price. Sensitivity analysis of the RHEM input parameters showed that the splash and sheet erodibility coefficient (Kss) and the effective saturated conductivity coefficient (Ke) had the largest influence on the model’s sediment and discharge outputs, respectively. The regression that predicted TDS concentration from sediment was applied to RHEM outputs to show that the model could be used to provide salinity estimates for different storm intensities on this part of the Mancos Shale. The potential influence of vegetation canopy cover on sediment production from these two sites was inferred by running RHEM with canopy cover values ranging from 0% to 100%. This changed sediment output by 111% to -91% relative to the present vegetation cover. Measures of the geometry of soil and vegetation patches at Dry-X, such as fractal dimension index and proximity index, showed a relationship to error residuals from RHEM. As the vegetation becomes less isolated, more uniform, and the tortuosity of the bare soil area increases, observed sediment decreases relative to RHEM predictions. The results of this study will help land management agencies assess the feasibility of mitigation strategies for reducing sediment and salinity loads from the saline and sodic soils of the Mancos Shale formation and indicate a possible benefit to incorporating the parameters that describe the spatial pattern of vegetation in RHEM.
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Cronje, Arina. "Effect of canopy position on fruit quality and consumer preference for the appearance and taste of pears." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86367.
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Thesis (MScFoodSc) Stellenbosch University, 2014ENGLISH ABSTRACT: We aimed to determine how canopy position influences fruit quality and consumer preference for the eating quality and appearance of ‘Forelle’, ‘Bon Chrétien’ and ‘Bon Rouge’ pears. Our hypothesis was that consumer preference would be higher for the appearance and eating quality of outer canopy fruit. Our first trial investigated the effect of canopy position and cold storage duration on quality attributes and consumer preference for ‘Forelle’ pears. Mealiness was much more prevalent in outer canopy fruit in 2012 and after 9 and 12 weeks cold storage in 2011. In 2011, consumers preferred the eating quality of inner canopy pears that had been subjected to 12 and 16 weeks of cold storage while inner canopy pears were generally preferred in 2012. This study provides support for the mandatory 12 weeks cold storage of ‘Forelle’ pears. Our second trial investigated the effect of canopy position and harvest maturity within the commercial picking window on the quality attributes and consumer preferences for ‘Forelle’ pears. Inner canopy pears of harvest 1 (23 February) and harvest 2 (27 February) were significantly preferred in terms of eating quality. The general dislike for harvest 3 (13 March) pears and outer canopy fruit seemed to relate to an incidence of mealiness. Our results suggest that harvesting ‘Forelle’ pears at a firmness ≈6.2 kg will ensure that both inner and outer canopy pears have acceptable eating quality. In our third trial, fruit were harvested at commercial firmness from two orchards in each of Elgin and Ceres to assess the effect of orchard site on quality attributes of ‘Forelle’ pears. Total soluble solids (TSS) were higher in Elgin while flavour attributes were more pronounced in Ceres. In both areas, outer canopy pears were higher in TSS and lower in titratable acidity (TA) but canopy position had no effect on sweet and sour taste. Mealiness incidence was high in outer canopy fruit from Elgin, as well as in one Ceres orchard. Further research over consecutive seasons is needed to determine the reasons for orchard differences in mealiness incidence. Our fourth trial investigated the effect of canopy position on quality attributes and consumer preference for ‘Bon Chrétien’ and ‘Bon Rouge’ pears. Despite a higher TSS:TA ratio in outer canopy ‘Bon Rouge’ pears and a higher TSS and dry matter concentration in outer canopy ‘Bon Chrétien’ pears, canopy position did not affect sensory eating quality attributes. Seen overall, results indicate that canopy position has a minor effect on consumer preference for ‘Bon Chrétien’ and ‘Bon Rouge’ eating quality. No significant differences in colour and consumer preference for appearance were found between outer and inner canopy ‘Bon Chrétien’ pears. Consumers slightly preferred the redder outer canopy ‘Bon Rouge’ pears over the less red inner canopy fruit. Although consumers preferred the red blush colour of outer canopy ‘Forelle’ pears, inner canopy pears also received high scores. Inner canopy ‘Forelle’ pears should not be viewed as inferior to outer canopy fruit with regard to both eating quality and appearance.
AFRIKAANSE OPSOMMING: Ons het gepoog om die effek van boomposisie op vrugkwaliteit en verbruikersvoorkeur vir die eetkwaliteit en voorkoms van ‘Forelle’, ‘Bon Chrétien’ en ‘Bon Rouge’ pere te ondersoek. Ons hipotese was dat verbruikersvoorkeur hoër sou wees vir die voorkoms en eetkwaliteit van pere van die buitekant van die boom se blaredak. Ons eerste proef se doelstelling was om die effek van boomposisie en koelopberging op die kwaliteitseienskappe en verbruikersvoorkeur vir ‘Forelle’ pere te bepaal. Melerigheid was beduidend meer aanwesig in buitevrugte in 2012 asook na 9 en 12 weke koelopberging in 2011. Verbruikersvoorkeur vir eetkwaliteit was die hoogste vir binnevrugte na 12 en 16 weke koelopberging in 2011 terwyl binnevrugte in die algemeen voorkeur geniet het in 2012. Hierdie studie steun die bevindinge van vorige studies dat ‘Forelle’ pere vir ten minste 12 weke koelopgeberg moet word. Die doel van ons tweede proef was om te bepaal of ‘Forelle’ pere wat by verskillende ryphede binne die kommersiële oesperiode geoes is, verskille toon in kwaliteitseienskappe en of hierdie verskille, indien enige, verband hou met verbruikersvoorkeur vir eetkwaliteit. Die eetkwaliteit van binnevrugte van oes 1 (23 Februarie) en oes 2 (27 Februarie) is verkies bo buitevrugte. Die algemene afkeur vir oes 3 (13 Maart) en buitevrugte kan moontlik toegeskryf word aan die hoë voorkoms van melerigheid. Ons resultate dui aan dat beide binne- en buitevrugte aanvaarbare eetkwaliteit behoort te hê indien ‘Forelle’ pere by ‘n fermheid van ≈6.2 kg geoes word. Vir ons derde proef is ‘Forelle’ pere geoes by kommersiële fermheid (≈6.4 kg) vanaf twee boorde in elk van Elgin en Ceres. Totale opgeloste vastestowwe (TOV) was hoër in Elgin pere terwyl geur-eienskappe meer prominent was in Ceres pere. In beide areas het buitevrugte hoër TSS en laer titreerbare sure (TS) gehad, maar boomposisie het egter geen effek op soet en suur smaak gehad nie. Die voorkoms van melerigheid was hoog in buitevrugte van die Elgin boorde, sowel as in een van die Ceres boorde. Verdere navorsing oor opeenvolgende seisoene word benodig om redes vir die verskille in die voorkoms van melerigheid tussen boorde te ondersoek. Die doelstelling van ons vierde proef was om die effek van boomposisie op die kwaliteitseienskappe en verbruikersvoorkeur vir ‘Bon Chrétien’ en ‘Bon Rouge’ pere te ondersoek. Ondanks ‘n hoër TOV:TS ratio in ‘Bon Rouge’ buitevrugte en ‘n hoër TOV en droë massa konsentrasie in ‘Bon Chrétien’ buitevrugte, het boomposisie ‘n minimale impak gehad op sensoriese eetkwaliteitseinskappe en verbruikervoorkeur vir die pere. Boomposisie het geen effek op die kleur en verbruikersvoorkeur vir die voorkoms van ‘Bon Chrétien’ pere gehad nie. Verbruikers het ‘n effense hoër voorkeur getoon vir die rooier ‘Bon Rouge’ buitevrugte. Alhoewel verbruikers die aantreklike rooi bloskleur van ‘Forelle’ buitevrugte verkies het, het die groen tot geel binnevrugte ook hoë voorkeurpunte behaal. Rakende voorkoms en eetkwaliteit, is ‘Forelle’ binnevrugte glad nie minderwaardig teenoor buitevrugte nie.
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Sen, Susmita. "Characterizing Impacts of and Recovery from Surface Coal Mining in Appalachian Forested Landscapes Using Landsat Imagery." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/38737.
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This dissertation describes research investigating the potential for using Landsat data to identify and characterize woody canopy cover on reclaimed coal-mined lands through three separate studies. The objective of the first study was to assess whether surface coal mines in the forested central Appalachian regions of the US can be separated from the other prevalent forest-replacing disturbances through analysis of an interannual chronosequence of Landsat images. Disturbances were classified using descriptors of the disturbance/recovery trajectories: disturbance minimum, recovery slope and recovery maximum. Three vegetation indices (VIs) (normalized difference vegetation index, NDVI; tasseled cap greenness/brightness ratio, TC G/B; and inverse of Landsat band 3, B3I) were used to analyze multitemporal trajectories generated using both pixels and objects. Classification accuracies using objects were better than those obtained using pixels for all VIs. The highest object-based classification accuracy was achieved using TC G/B (89%), followed by NDVI (88%) and B3I (80%). The objective of the second study was to evaluate performance of a woody canopy cover (including both native and invasive species) estimation method based on the 2011 National Land Cover Database (NLCD) protocol for both mined and non-mined areas of the central Appalachians. Potential explanatory variables included raw and derived bands from leaf-on and leaf-off Landsat scenes plus terrain descriptors. Results show that the model developed to estimate canopy cover for mines (R2 = 0.78, Adj. R2 = 0.77, RMSE = 16%) is more robust than the models developed for non-mines, mixed, and all areas combined. The objective of the third study was to determine whether four disturbance/recovery parameters (recovery time, disturbance minimum, recovery slope, and recovery maximum), alone or in combination with variables identified in the second study, enable robust estimation of woody canopy cover on reclaimed surface coal mines. Of the disturbance/recovery parameters, only recovery time made a significant contribution to the model (R2 0.45, Adj. R2 0.44, RMSE 14%). Addition of leaf-on and leaf-off NDVI improved the R2 to 0.54 (Adj. R2 0.53, RMSE 13%). Analysis of Landsat data has strong potential for identifying reclaimed mines and characterizing the extent to which woody canopy has recovered post-reclamation.Ph. D.
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Horcher, Andy. "Improving Helicopter Yarding with Onboard GPS." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/26678.
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Despite its relatively high cost, helicopter yarding has become a common means of timber extraction where site sensitivity, access, or regulations limit the use of less costly alternatives. The high costs associated with helicopter yarding, as well as the desire to expand the application of this system to extract lower value timber, increases the need for innovation to improve the operations.
The cost or benefit of a particular harvest prescription or innovative technique is commonly assessed with a time and motion study. Capturing time study data require additional personnel or an imposition on the operator to record additional information. Onboard GPS can reduce or eliminate the need for additional personnel and/or operator input providing a rapid means of assessing and improving helicopter operations.
This research employed onboard GPS in helicopter yarding to assess the potential of developing time studies using GPS data. Three helicopter models were sampled on a total of nine sites. Three of the sites have both experienced and inexperienced pilot data. Hemispherical canopy images were sampled at three sites. This complement of data permitted the following analysis: assessment of differences between experienced and inexperienced pilots, assessment of canopy cover on hook time, and the development of production models.
The results indicate onboard GPS and the automated processing methods are suitable for creating time study data. Specifically, in all three case studies quantitative results were obtained, analyzed and opportunities for improvement identified. The time penalty suffered from using inexperienced pilots created 64 to 94% additional turn time. Increasing canopy cover correlated with increased hook time at two sites for the zenith angle segment 0 â 15°. Regressions assessing production show distance, slope, and choker delivery to be significant. This research shows the combination of onboard GPS, the automation process, and commonly collected turn information presents a number of opportunities, enabling the assessment of a wide range of helicopter yarding conditions.Ph. D.
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Mobe, Nompumelelo Thelma. "The influence of canopy cover and cultivar on rates of water use in apple orchards in the Western Cape Province, South Africa." University of the Western Cape, 2020. http://hdl.handle.net/11394/8156.
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Philosophiae Doctor - PhDWater availability and climate related issues are some of the greatest crop production risks to irrigated agriculture in arid regions. In South Africa, for example, the increasing frequency and severity of droughts related to climate change and the growing competition for limited water resources among different users threaten the sustainability and growth of irrigated agriculture, especially the water-intensive fruit industry. Major fruit such as apples (Malus domestica Borkh) are produced entirely under irrigation in South Africa. As a result, there has been considerable research to accurately quantify the water requirements of fruit tree orchards in order to maximize water productivity.
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Cai, Bill Yang. "Applications of deep learning and computer vision in large scale quantification of tree canopy cover and real-time estimation of street parking." Thesis, Massachusetts Institute of Technology, 2018. https://hdl.handle.net/1721.1/122317.
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Thesis: S.M., Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2018Cataloged from PDF version of thesis.
Includes bibliographical references (pages 73-77).
A modern city generates a large volume of digital information, especially in the form of unstructured image and video data. Recent advancements in deep learning techniques have enabled effective learning and estimation of high-level attributes and meaningful features from large digital datasets of images and videos. In my thesis, I explore the potential of applying deep learning to image and video data to quantify urban tree cover and street parking utilization. Large-scale and accurate quantification of urban tree cover is important towards informing government agencies in their public greenery efforts, and useful for modelling and analyzing city ecology and urban heat island effects. We apply state-of-the-art deep learning models, and compare their performance to a previously established benchmark of an unsupervised method.
Our training procedure for deep learning models is novel; we utilize the abundance of openly available and similarly labelled street-level image datasets to pre-train our model. We then perform additional training on a small training dataset consisting of GSV images. We also employ a recently developed method called gradient-weighted class activation map (Grad-CAM) to interpret the features learned by the end-to-end model. The results demonstrate that deep learning models are highly accurate, can be interpretable, and can also be efficient in terms of data-labelling effort and computational resources. Accurate parking quantification would inform developers and municipalities in space allocation and design, while real-time measurements would provide drivers and parking enforcement with information that saves time and resources. We propose an accurate and real-time video system for future Internet of Things (IoT) and smart cities applications.
Using recent developments in deep convolutional neural networks (DCNNs) and a novel intelligent vehicle tracking filter, the proposed system combines information across multiple image frames in a video sequence to remove noise introduced by occlusions and detection failures. We demonstrate that the proposed system achieves higher accuracy than pure image-based instance segmentation, and is comparable in performance to industry benchmark systems that utilize more expensive sensors such as radar. Furthermore, the proposed system can be easily configured for deployment in different parking scenarios, and can provide spatial information beyond traditional binary occupancy statistics.
by Bill Yang Cai.
S.M.
S.M. Massachusetts Institute of Technology, Computation for Design and Optimization Program
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Chen, Yi-Huei. "Effects of altitude and canopy cover on the nest size and colony size of the red wood ants Formica lugubris and Formica paralugubris." Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/8476/.
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Variations in life-history characteristics across geographic gradients may have implications for the impact of environmental change on animals. Linking one of the most important life-history characteristics and a geographic gradient, Bergmann’s rule describes body size increase with increasing latitude. Due to comparable thermal patterns between latitude and altitude, a similar process is expected to apply across altitude. For social insects, the colony could be biologically analogous to the body of a unitary organism. This study investigates the relationship between altitude and colony size in social insects. The model species used were wood ants Formica lugubris and F. paralugubris. These species have a flexible nesting strategy known as polydomy. I therefore considered both nest size and colony size. Initially, I developed an accurate mark-release-recapture method to estimate nest size, and found that mound volume can be a useful nest size index. A detailed case-study focused on canopy cover effects and showed that nests were larger in shadier areas. Informed by the results, I finally assessed the relationship between altitude, canopy cover, polydomy, nest size and colony size. The results reveal that colony size follows Bergmann’s rule along altitude when canopy cover is controlled for: microclimatic factors can be more significant than geographic factors in determining colony size. A systematic review in the Appendix shows that F. lugubris populations in different locations differ in mean nest size, but shows no evidence of a trade-off between nest size and multi-nest organisation. This thesis not only provides the first intra-specific evidence of Bergmann’s rule acting at the colony level across altitude, but also indicates the prominent role of microclimate on a key life-history characteristic. The work therefore sheds light on the evolution of an eco-geographic cline and the effects which climate change may have on the cline.
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Veatch, William Curtis. "Quantifying the Effects of Forest Canopy Cover on Net Snow Accumulation at a Continental, Mid-Latitude Site, Valles Caldera National Preserve, NM, USA." Thesis, The University of Arizona, 2008. http://hdl.handle.net/10150/193352.
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Although forest properties are known to influence snowpack accumulation and spring runoff, the processes underlying the impacts of forest canopy cover on the input of snowmelt to the catchment remain poorly characterized. In this study I show that throughfall and canopy shading can combine to result in maximal snowpacks in forests of moderate canopy density. Snow depth and density data taken shortly before spring melt in the Jemez Mountains of New Mexico show strong correlation between forest canopy density and snow water equivalent, with maximal snow accumulation in forests with density between 25 and 45%. Forest edges are also shown to be highly influential on local snow depth variability, with shaded open areas holding significantly deeper snow than either unshaded open or deep forest areas. These results are broadly applicable in improving estimates of water resource availability, predicting the ecohydrological implications of vegetation change, and informing integrated water resources management.
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Olsson, Cecilia. "Amphibian and reptile distribution in forests adjacent to watercourses." Thesis, Karlstad University, Faculty of Social and Life Sciences, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-3301.
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Worldwide amphibians and reptiles are declining with habitat fragmentation and destruction as the primary cause. Riparian areas are important for the herpetofauna, but as land is converted to agriculture or harvested for timber the areas are diminishing. The aim of this study was to examine amphibian and reptile abundance in relation to distance from water and in relation to habitat characteristics, foremost per cent deciduous trees. The survey was conducted during spring at six different locations, with continuous forest along streams or rivers, outside of Karlstad, Sweden. Animals were searched along four lines parallel to the water and each study area was visited five times. Statistical analyses were made for grass snake (Natrix natrix), common lizard (Lacerta vivipara) and frogs with joined data of common frog (Rana temporaria) and moor frog (R. arvalis). As expected both reptiles were positively correlated with per cent deciduous trees, with the strongest significance for the common lizard. For grass snake there was also a difference between survey periods, which might reflect the importance of weather. Frogs revealed no trends to trees, but there was a significant difference for habitat characteristics like amount woody debris and per cent bare ground. None of the species were correlated with distance from water which was surprising, especially for the frogs which is more dependent on water than the reptiles. Grass snakes hunt in the water, but the common lizard has no such associations to the water, yet the latter did reveal a slight trend towards being more numerous closer to the water. The causes behind lacking correlation to distance from water may be many, but water characteristics seem very important. Many amphibians prefer warm and calm ponds over running water that in general are colder and likely to inhabit more predators. It was assumed that the amphibians breed in the streams or rivers, but it is possible that other water bodies may have served as breeding sites, which mean the starting point was incorrect.
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Kamboyi, Chipango. "COMPARING THE COMPOSITION OF SAPROXYLIC BEETLE FAUNA ON OLD HOLLOW OAKS BETWEEN TWO TIME PERIODS." Thesis, Linköpings universitet, Biologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-162441.
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Oak habitats are rich in saproxylic species, but the habitat is declining with loss of diversity due to encroachment which decrease the vitality of oaks. The present explorative study compared results from a study conducted in 1994, with present species communities to observe if there has been change in species composition and what factors that can explain species diversity and composition. The results revealed that the overall species composition between 1994 and 2018 has changed. There were 130 species recorded in 2018 compared to 108 species in 1994 (31 new species were recorded in 2018, and 9 species lost from the study in 1994). There was a high species turnover recorded per individual tree, and the species composition between the living and encountered dead trees did not differ. Species composition was affected by canopy cover, and trunk circumference (CCA P-value 0.001 and 0.014 respectively). Unlike 1994, there were no variables in 2018 that could explain the association with species numbers. Warmer conditions recorded during the sampling period have probably led to increased flight activity of beetles and therefore increasing chances of capturing more species and individuals. The warmer conditions possibly shadowed the effects of the explanatory variables in explaining the changes in species numbers. Perhaps the change in species composition could also be attributed to existing management interventions that may be supporting an increasing species number of saproxylic beetles, however no strong conclusions could be drawn. Management interventions such as the recruitment of new oaks should be encouraged and intensified in order to provide habitats and support stable populations as the loss of oaks may lead to increased risk of extinction of the saproxylic beetles in the study area.
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Khokthong, Watit [Verfasser], Dirk [Akademischer Betreuer] Hölscher, Dirk [Gutachter] Hölscher, Holger [Gutachter] Kreft, and Christian [Gutachter] Ammer. "Drone-based assessments of crowns, canopy cover and land use types in and around an oil palm agroforestry experiment / Watit Khokthong ; Gutachter: Dirk Hoelscher, Holger Kreft, Christian Ammer ; Betreuer: Dirk Hoelscher." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1183374763/34.
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Khokthong, Watit Verfasser], Dirk [Akademischer Betreuer] [Hölscher, Dirk [Gutachter] Hölscher, Holger [Gutachter] Kreft, and Christian [Gutachter] Ammer. "Drone-based assessments of crowns, canopy cover and land use types in and around an oil palm agroforestry experiment / Watit Khokthong ; Gutachter: Dirk Hoelscher, Holger Kreft, Christian Ammer ; Betreuer: Dirk Hoelscher." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1183374763/34.
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Guo, Fen. "The Influence of Light and Nutrients on Stream Food Webs." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/366591.
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While many streams and rivers are dominated by terrestrial inputs of organic carbon, algae are important trophic base for stream food webs. However, the nutritional importance of algae for stream invertebrates has only recently been highlighted. Algae are acknowledged as higher quality food compared with terrestrial organic matter for the growth and reproduction of invertebrates. In part, this is because of algal higher polyunsaturated fatty acid (PUFA) content. Current studies on algal PUFA and their effect on invertebrates are mainly from lacustrine systems, and only few studies have explicitly investigated algal PUFA in streams. This thesis aimed to evaluate the role of algal food quality, as assessed by PUFA, in stream food webs by using a range of methods literature review, field investigation, field manipulative study and laboratory feeding experiment. All experiments involved in this thesis were conducted in subtropical streams in South-East Queensland, Australia.
Riparian canopy cover and NOx-N concentrations were identified as the two most important factors affecting periphyton PUFA profiles. Periphyton eicosapentaenoic (EPA, 20:5ω-3) and docosahexaenoic (DHA, 22:6ω-3) were positively correlated with canopy cover and NOx-N concentrations, whereas α-linolenic (ALA, 18:3ω-3) and linoleic acid (LIN, 18:2ω-6) were positively correlated with NOx-N, but negatively with canopy cover. Variations in riparian canopy cover and nutrients gave rise to opposite outcomes in terms of periphyton food quality and quantity. The highest periphyton food quality occurred in streams with high canopy cover and low nutrients, while the highest periphyton food quantity occurred in streams with low canopy cover.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Martell, Linn. "Ljusklimatet i skogsvattendrag : Skillnader i förhållande till skogens ålder." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-81476.
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På grund av hårt skogsbruk har den generella skogsstrukturen i Sverige förändrats, vilket har påverkat ljusklimatet i skogsvattendrag. Övergången från gammal skog till yngre produktiv skog i kantzonen längs vattendrag har lett till ett strukturellt skifte mot mer enskiktade krontak som förmodligen lämnar lite utrymmer för ljus att tränga igenom. Ljus är en fundamental faktor som möjliggör många ekologiska processer i skogsvattendrag, vilket gör det till en viktig aspekt att undersöka för att kunna upprätthålla ett hållbart skogsbruk. Denna studie avsåg att undersöka ljusklimatet i skogsvattendrag, med syftet att utreda om det fanns skillnader i förhållande till skogens ålder. Studien utfördes i augusti 2020 i Stockholms län, och innefattade fem vattendrag i medelåldrig skog (40 – 80 år) samt fem i gammal skog (>140 år). Krontakstäckning uppskattades genom hemisfäriska foton tagna med en fish-eye lins vid åtta punkter i varje provlokal, och analyserades med hjälp av en mobilapplikation (GLAMA). En inventering av träd i kantzonerna utfördes enligt point-centered quarter method, och datan användes för att beräkna träddensitet, artrikedom samt absolut densitet för varje påträffad art. Resultaten visade en liten men icke-signifikant skillnad i krontakstäckning mellan ålderskategorierna, med en något högre medelprocent i gammal skog. Både medelåldrig och gammal skog dominerades av gran, och artsammansättningen var lika oavsett ålderskategori. Träddensiteten skilde sig något mellan kategorierna, med indikationer på en högre medeldensitet i gammal skog. Ytterligare studier krävs för att minska osäkerheter samt vidare öka kunskaperna om skogsbrukets effekter för att kunna bevara de akvatiska och terrestra miljöerna i skogsekosystem.Due to intensive forestry, the general stand structure in Swedish forests has changed, which in turn has affected light availability in forest streams. The transformation from old growth to younger productive forests in the riparian zone has led to a structural shift towards a higher density and single-leveled canopies that limits light penetration. Light is a fundamental factor promoting many ecological processes in forest streams, which makes it an important feature to examine in a sustainable forestry context. This study investigated the light climate in forest streams, with the purpose to look for differences in relation to forest age. The study was conducted in August 2020 in Stockholm County, and consisted of five streams in middle stage forests (40 – 80 years) and five in old growth forests (>140 years). Canopy closure was estimated using hemispherical photos taken with a fish-eye lens at eight sample points within each site and analyzed with a mobile app (GLAMA). An inventory of trees in the riparian zone was carried out according to the point-centered quarter method, and the data were used to measure tree density, species richness and absolute density of each observed species. The results showed small non-significant differences in canopy closure between age categories, with a higher mean percentage in old growth forests. Both middle stage and old growth forests were dominated by spruce, and the species richness was the same regardless of age category. The tree density differed slightly between categories, with a tendency for a higher mean density in old growth forests. Further research is needed to reduce uncertainty and expand on the effects of forestry if we are to sustain the aquatic and terrestrial environments in forest ecosystems.
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Salazar, Ana. "Seed Dynamics and Seedling Establishment of Woody Species in the Tropical Savannas of Central Brazil (Cerrado)." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/371.
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Studies of seed dynamics and seedling establishment at the community level in savanna ecosystems are scant, particularly in the tropical savannas of Central Brazil. The Brazilian savannas (cerrado) have the largest diversity of plant species among Neotropical savannas. Cerrado vegetation exhibits consistent changes in tree density and tree size along shallow topographic gradients. Vegetation types differ from closed savannas with high tree density, and a nearly continuous canopy cover in the uppermost portions, to open savannas with scattered short trees in the low portions of the topographic gradients. Whether or not dynamics of seeds and seedlings of woody species are consistent with variations in tree density and tree canopy cover across the cerrado landscape has not been determined, but could potentially influence such spatial patterns of tree density and canopy cover. The main objective of this study was to evaluate seed dynamics (i.e., seed rain, soil seed banks, and seed characteristics) and seedling establishment of woody species in three major cerrado vegetation types (closed, intermediate and open savannas) which differ in tree canopy cover and tree height. These vegetation types are located along topographic gradients of approximately 30 m in elevation and 1000 m in length. I conducted field work from June 2005 to August 2008 at the Instituto Brasileiro de Geografia e Estatística (IBGE) reserve, a field experimental station located 35 Km south of Brasilia, Brazil (15˚ 56' S, 47˚ 63' W, altitude 1100 m). I established permanent plots in each of the three vegetation types to assess seed rain, seed limitation, seed predation, and seed removal. I also quantified density and composition of the soil seed bank in each vegetation type and studied seed characteristics (i.e., kind of dormancy, moisture content, longevity) of 14 common cerrado woody species. In the field, I quantified establishment of woody seedlings in fire-protected savannas as well as in accidentally burned and frequently burned savannas. In the greenhouse I performed experiments to evaluate the effect of litter cover and light level on seedling emergence of 9 common cerrado woody species. Finally, I evaluated the effect of pulses of heat on seed germination of 5 common cerrado woody species under controlled conditions. The overall results of this study show that regardless of tree canopy cover, cerrado vegetation types are limited in seeds and seedlings of woody species, but these limitations are higher in open than in closed savannas. Most woody species do not form persistent soil seed banks along cerrado vegetation types because their seeds are short-lived, predated and quickly removed from the ground. In addition, dispersal season and dormancy appear to control timing of germination at the onset of the rainy season to ensure survival of seedlings in the field. In the absence of fire, establishment of woody seedlings is higher in closed than in open savannas because canopy cover mitigates the stressful environmental conditions of open savannas and thus facilitates establishment of woody seedlings. As a result, closed savannas are likely to maintain higher density of woody elements over time than open savannas. In burned savannas, however, species composition of woody and herbaceous seedlings is significantly affected because establishment of seedlings of woody and herbaceous species decreases but vegetative reproduction increases. This dissertation study indicates that interactions of early life-history stages of woody species with environmental and disturbance factors appear to play a more significant role in maintaining woody cover variations along cerrado topographic gradients than previously recognized.
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Purrenhage, Jennifer Lyn. "Importance of Habitat Structure for Pond-Breeding Amphibians in Multiple Life Stages." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1240957514.
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Riley, Christopher B. "Quantifying the Ecosystem Services and Functions of Forests across Diverse Urban Landscapes." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574414361328737.
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Hurskainen, S. (Sonja). "The roles of individual demographic history and environmental conditions in the performance and conservation of northern orchids." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526220888.
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Abstract A population growth rate is the sum of all individuals’ reproduction and survival, which in turn depend on many external and internal factors, e.g. weather and individual reproductive history. In plants, for example, previous reproduction can deplete an individual’s resources, resulting in trade-offs between demographic functions. To understand these demographic processes, it is necessary to follow populations for many years. Such long-term studies are especially crucial for endangered species, as they can reveal the causes of population declines and provide information that is directly applicable for the management. In my thesis, I applied this approach to the study of rare orchids. Specifically, I analyzed long-term orchid monitoring data from two countries, Finland and Estonia, to assess the external and internal factors that affect the performance of these long-lived plants, which reproduce both sexually (via seeds) and vegetatively (via new ramets). My research reveals that plant performance depends on both the demographic history and the environment of a plant. For example, although Finnish and Estonian populations of the lady’s slipper orchid, Cypripedium calceolus, differed in direction and statistical significance of their responses to environmental factors, the two most-influential weather variables in both cases were spring snow depth and the temperature of the previous summer. However, the influence of weather on both flowering and vegetative growth was dwarfed by the effect of plants’ own demographic histories: there was a trade-off between current and future reproduction which created asynchronous two-year cycles in reproduction and growth. Furthermore, in all three studied orchid species — the lady’s slipper orchid (C. calceolus), the fairy’s slipper orchid (Calypso bulbosa), and the dark-red helleborine (Epipactis atrorubens) — the probability of dormancy (a state in which the plant spends a year or more underground) and the demographic costs this state incurred with respect to size or future reproduction depended on a plant’s size and whether it flowered prior to dormancy. In other words, dormancy had both absolute and relative costs in large, but not in small, individuals. Finally, I show here that environmental alteration via selective tree removal can be used as a management method to increase orchid reproduction via both seeds and rametsTiivistelmä Populaation kasvunopeus riippuu siitä, kuinka monta yksilöä populaatioon syntyy ja kuinka monta yksilöä kuolee. Yksilöiden lisääntyvyyteen ja elossa säilyvyyteen puolestaan vaikuttavat monet ulkoiset ja sisäiset tekijät, kuten sää ja yksilön oma lisääntymishistoria. Kasvilla on rajallinen määrä resursseja, joten sen pitää tehdä kompromisseja eri elintoimintojen, esimerkiksi kasvun ja lisääntymisen, välillä. Klonaaliset kasvit voivat myös lisääntyä usealla tavalla: joko suvullisesti siemenistä tai kasvullisesti tuottamalla uusia versoja. Demografisten prosessien tutkimisessa pitkäaikaiset seuranta-aineistot ovat välttämättömiä. Pitkäaikaisseurannat voivat myös paljastaa uhanalaisen lajin populaation taantumisen syyt ja näistä seurannoista saatua tietoa voidaan soveltaa harvinaisten lajien, esimerkiksi kämmeköiden, suojelutoimien suunnittelussa. Tässä väitöskirjassa analysoin aineistoa kämmeköiden pitkäaikaisseurannoista Suomesta ja Virosta. Tavoitteenani oli arvioida ulkoisten ja sisäisten tekijöiden merkitystä pitkäikäisten kasvien menestykselle. Tulokset osoittavat, että kasvin menestys riippuu sekä yksilön omasta demografisesta historiasta että sen ympäristöstä. Eri säätekijöiden vaikutus tikankontin (Cypripedium calceolus) kasvuun ja kukkimiseen vaihteli Suomen ja Viron välillä, mutta lumen syvyys ja edellisen kasvukauden lämpötila nousivat merkittävimmiksi tekijöiksi molemmissa maissa. Tikankontin kasvu ja kukinta riippuivat kuitenkin säätä enemmän kasvin omasta demografisesta historiasta. Runsas lisääntyminen edeltävällä kasvukaudella vähensi lisääntymistä tulevalla kasvukaudella, mikä johti kaksivuotiseen jaksottaisuuteen tikankontin lisääntymisessä ja kasvussa. Tutkiessani dormanssia (lepotila, jossa kasvi ei tuota maanpäällistä versoa) kolmella kämmekkälajilla, tikankontilla, neidonkengällä (Calypso bulbosa) ja tummaneidonvaipalla (Epipactis atrorubens), havaitsin lisäksi, että todennäköisyys siirtyä dormanssiin riippui kasvin koosta. Myöskin tämän lepotilan aiheuttamat kustannukset olivat riippuvaisia kasvin aikaisemmasta tilasta. Isoilla kasveilla dormanssilla oli sekä suoria kustannuksia että kustannuksia suhteessa versomiseen. Pienillä kasveilla näitä kustannuksia ei ollut. Osoitan väitöskirjassani myös, että maltillisella puunpoistolla voidaan lisätä tikankonttipopulaatioiden siementuottoa ja versotiheyttä
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Klinka, Karel. "Natural regeneration on clearcuts at the lower limit of the mountain hemlock zone." Forest Sciences Department, University of British Columbia, 1997. http://hdl.handle.net/2429/654.
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The Mountain Hemlock (MH) zone includes all subalpine forests along British Columbia’s coast. It occurs at elevations where most precipitation falls as snow and the growing season is less than 4 months long. The zone includes the continuous
forest of the forested subzones and the tree islands of the parkland subzones (Figure 1). Old-growth stands are populated by mountain hemlock, Pacific silver fir, and Alaska
yellow-cedar, and are among the least-disturbed ecosystems in the world. Canopy trees grow slowly and are commonly older than 600 years, while some Alaska yellow-cedars may be up to 2000 years old.
Early regeneration failures followed slashburning and the planting of unsuitable species. Currently, the most successful and feasible option for reforesting cutovers is natural
regeneration with a mix of the three main tree species, but uncertainties remain about the temporal and spatial pattern of regeneration, changes in species composition, and the time
required for stand establishment after cutting. Our study addressed these concerns by examining regeneration patterns on 6 sites that were clearcut 11-12 years prior to sampling and left to regenerate naturally. The sites were located at the lower
limits of the zone in the Tetrahedron Range, near Sechelt, at elevations from 1060-1100m.
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Yamada, Thiago. "Técnicas de processamento digital de imagens para análise de integridade do dossel - um modelo em mata semidecídua." Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/1824.
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Previous issue date: 2014-02-28Financiadora de Estudos e Projetos
The forests management and conservation are recently subjects discussed throughout the world, because they are directly correlation with the maintenance of environmental functions and services provided by natural environments. With growth of urban centers and extensive agriculture the natural areas have suffered and are suffering a big pressure making arise degraded areas constantly that encourage the recuperation movement in those areas. Moreover, the selective cut and the formation natural or artificial clearings make discontinuities in the canopy, irregularities reflected in the structure and profile. However, to realize the restoration and management, for example, a forest, first must to know your conservation state. This thesis intend to map more and less conserved areas through the analysis of structure and integrity in the canopy, realized with: canopy cover images, canopy closure images, vertical profile sketch, panchromatic image HRC of satellite CBERS-2B, and techniques digital image processing, beyond field survey. With intention to create a model able to identify, map, and monitor the forest degraded.
A conservação e manejo das florestas são temas muito atuais e discutidos em todo mundo, devido ao fato de estarem diretamente correlacionados com a manutenção das funções e serviços ambientais prestados pelos ambientes naturais. Com o crescimento dos centros urbanos e da agricultura extensiva, as áreas naturais sofreram e estão sofrendo uma grande pressão fazendo com que surjam constantemente áreas degradadas que acabam impulsionando o movimento de recuperação dessas áreas. Além disso, o corte seletivo e a formação de clareiras naturais ou artificiais produzem descontinuidades no dossel, refletindo em irregularidades na estrutura e no perfil. No entanto, para se realizar a recuperação e manejo, por exemplo, de uma floresta, deve-se primeiro conhecer seu estado de conservação. Esta tese pretende mapear áreas mais e menos conservadas, através da análise da estrutura e integridade do dossel, realizada com: imagens da cobertura do dossel, imagens da oclusão do dossel, desenho do perfil vertical, imagem pancromática HRC do satélite CBERS-2B e técnicas de processamento digital de imagens, além de levantamentos de campo. Com o intuito de criar um modelo capaz de identificar, mapear e monitorar a degradação de uma floresta.
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Kriska, David J. "Restoration of Black Oak (Quercus velutina) Sand Barrens via three different habitat management approaches." Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu1506811044845704.
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Dodonov, Pavel. "Influência de borda sobre vegetação e microclima no cerrado paulista." Universidade Federal de São Carlos, 2011. https://repositorio.ufscar.br/handle/ufscar/2009.
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Previous issue date: 2011-02-04Universidade Federal de Minas Gerais
There is much variation in patterns of edge influence (EI) within a region due to factors such as vegetation structure, adjacent land use, orientation and edge contrast, and assessment of this variation is important for conservational planning. We studied EI on aspects of microclimate and vegetation in seven cerrado fragments in South-Eastern Brazil, sampling both savanna and forest vegetation. We located transects perpendicular to 14 cerrado edges adjacent to pastures, highways, sugarcane, silviculture, urban area, and forest roads. When significant, distance of EI varied from 15 to 80 m for temperature, 2 to 50 m for air moisture, 2 to 20 m for maximum vegetation height, 2 m for wind speed, 0 to 100 m for canopy cover, 0 to 20 m for exotic grass biomass, and 0 to 10 m for native grass biomass. The largest EI was observed in areas adjacent to pastures, but factors such as orientation, vegetations structure and land use were not sufficient to explain the observed variability. For conservation purposes, we recommend that buffers should be created between cerrado and the adjacent land use, especially in fragments adjacent to pastures and higways, in order to reduce EI.
Existe ampla variação nos padrões de influência de borda (IB) dentro de uma região, devido a fatores como estrutura da vegetação, uso da terra adjacente, orientação e contraste da borda. Entender esta variação é importante para o planejamento direcionado à conservação. Nós estudamos IB sobre aspectos de microclima e vegetação em sete fragmentos de cerrado no Sudeste do Brasil, amostrando áreas tanto de savana quanto de floresta. Nós delimitamos transectos perpendiculares a 14 bordas de cerrado adjacentes a pastagens, estradas, cana-de-açucar, silvicultura, área urbana e aceiros. Quando significativa, a distância de influência de borda variou de 15 a 80 m para temperatura, 2 a 50 m para umidade do ar, 2 m para velocidade do vento, 2 a 20 m para altura máxima de vegetação, 0 a 100 m para cobertura de dossel, 0 a 20 m para biomassa de gramíneas exóticas e 0 a 10 m para biomassa de gramíneas nativas. A maior IB foi observada em áreas adjacentes a pastages, mas fatores como orientação, estrutura da vegetação e uso da terra não foram suficientes para explicar a variabilidade observada. Para propósitos de conservação visando reduzir a IB, nós recomendamos a criação de zonas de amortecimento entre o cerrado e áreas adjacentes com outros usos da terra, especialmente em fragmentos adjacentes a pastagens e estradas.
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Karlson, Martin. "Remote Sensing of Woodland Structure and Composition in the Sudano-Sahelian zone : Application of WorldView-2 and Landsat 8." Doctoral thesis, Linköpings universitet, Tema Miljöförändring, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121536.
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Woodlands constitute the subsistence base of the majority of people in the Sudano-Sahelian zone (SSZ), but low availability of in situ data on vegetation structure and composition hampers research and monitoring. This thesis explores the utility of remote sensing for mapping and analysing vegetation, primarily trees, in the SSZ. A comprehensive literature review was first conducted to describe how the application of remote sensing has developed in the SSZ between 1975 and 2014, and to identify important research gaps. Based on the gaps identified in the literature review, the capabilities of two new satellite systems (WorldView-2 and Landsat 8) for mapping woodland structure and composition were tested in an area in central Burkina Faso. The results shows that WorldView-2 represents a useful data source for mapping individual trees: 85.4% of the reference trees were detected in the WorldView-2 data and tree crown area was estimate with an average error of 45.6%. In addition, WorldView-2 data produced high classification accuracies for five locally important tree species. The highest overall classification accuracy (82.4%) was produced using multi-temporal WorldView-2 data. Landsat 8 data proved more suitable for mapping tree canopy cover as compared to aboveground biomass in the woodland landscape. Tree canopy cover and aboveground biomass was predicted with 41% and 66% root mean square error, respectively, at pixel level. This thesis demonstrates the potential of easily accessible data from two satellite systems for mapping important tree attributes in woodland areas, and discusses how the usefulness of remote sensing for analyzing vegetation can be further enhanced in the SSZ.Merparten av befolkningen i Sudano-Sahel zonen (SSZ) är beroende av naturresurser och ekosystemtjänster från woodlands (öppen torrskog) för att säkra sin försörjning. Tillgången av fältmätningar av vegetationens struktur och sammansättning är mycket låg i detta område, vilket utgör ett problem för forskning och miljöövervakning. Denna avhandling undersöker nyttan av fjärranalys för att kartlägga och analysera vegetation, främst träd, i SSZ. En omfattande litteraturöversikt genomfördes först för att undersöka hur tillämpningen av fjärranalys har utvecklats i SSZ mellan 1975 och 2014, samt att identifiera viktiga forskningsluckor. Några av de luckor som konstaterades i litteraturgenomgången låg till grund för de följande studierna där två nya satellitsystem (Worldview-2 och Landsat 8) utvärderades för deras användbarhet att kartlägga trädtäckets struktur och artsammansättning i ett woodland-område i centrala Burkina Faso. Resultaten visar att Worldview-2 är en värdefull datakälla för kartering av enskilda träd: 85.4% av referensträden detekterades och trädkronornas storlek uppskattades med ett medelfel av 45.6%. Worldview-2-data producerade även hög klassificeringsnoggrannhet för de fem lokalt viktigaste trädslagen. Den högsta noggrannheten (82.4%) uppnåddes med multi-temporal Worldview-2-data. Landsat 8 data visade sig mer lämpade för kartering av krontäcke, jämfört med biomassa. Medelfelet för karteringen var 41% för krontäcke och 66% för biomassa, på pixelnivå. Avhandlingen visar att lättillgängliga data från två satellitsystem är användbara för kartläggning av viktiga trädattribut i woodlands, samt diskuterar hur nyttan av fjärranalys för vegetationsanalys kan ökas ytterligare i SSZ.
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BONARI, GIANMARIA. "DIFFERENT HABITAT AND TAXA: VARIOUS APPROACHES AND THEIR IMPLICATIONS FOR A LONG-SIGHTED MANAGEMENT AND CONSERVATION." Doctoral thesis, Università di Siena, 2017. http://hdl.handle.net/11365/1010508.
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The thesis starts in the continental context of the White Carpathians Protected Landscape Area and UNESCO Biosphere Reserve (Czech Republic), a protected area famous for its grasslands with the globally highest fine-scale plant species richness. The effects of management on species richness and composition of both plants and animals were tested in relation to different management practices (mowing, grazing, abandonment and mixed management) for several years at several sites, clarifying the disagreements that have occurred among conservationists and practitioners to date. The thesis continues with a focus on the Mediterranean context. Here, the distribution patterns of understorey assemblages of coastal pine stands on sand dunes were studied, given the scarcity of literature due to scholarly disdain. Using more than a hundred plots along Italian coastlines in different pine forest types, community similarity and specificity was assessed in order to provide lacking management clues. Subsequently, focusing on a pine forest stand located in Southern Tuscany, the thesis aimed to solve another pivotal question, namely by investigating the concordance of species assemblages between vascular plants, oribatid mites and soil chemical properties with special attention to the role of vegetation structure (i.e. tree, shrub and herbaceous cover) for biological components. This part provides new answers about congruence among communities and following appropriate management practices to be fulfilled for communities. The last part, performed along a wide range of Tuscan coasts, deals with one of the most extreme habitats in the Mediterranean basin: coastal dunes. Here, the understanding of the response of plant species to soil factors was estimated. This provides concrete proposals for the effective conservation of coastal habitats.
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Da, Ponte Canova Emmanuel [Verfasser]. "Assessment of forest cover dynamics in Paraguay A case study of the Upper Parana Atlantic Forest / Emmanuel Da Ponte Canova." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/1165574179/34.
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Da, Ponte Emmanuel [Verfasser]. "Assessment of forest cover dynamics in Paraguay A case study of the Upper Parana Atlantic Forest / Emmanuel Da Ponte Canova." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/1165574179/34.
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Lindgren, Jessica. "Small remnant habitats : Important structures in fragmented landscapes." Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148653.
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The world-wide intensification of agriculture has led to a decline in species richness due to land use change, isolation, and fragmentation of natural and semi-natural habitats in agricultural and forestry landscapes. As a consequence, there is a current landscape management focus on the importance of green infrastructure to mitigate biodiversity decline and preserve ecosystem functions e.g. pollination services and pest control. Even though intensification in agriculture has been ongoing for several hundreds of years, remnant habitats from earlier management practices may still be remaining with a surprisingly high plant richness. Preserving these habitats could help conserving plant species richness in agricultural landscapes, as well as other organisms that are dependent on plants for food and shelter. In this thesis I focus on two small remnant habitats; midfield islets and borders between managed forest and crop field in southeastern Sweden. In the past, both habitats were included in the grazing system and therefore often still have remnant population of grassland specialist species left today. I have used these two remnant habitats as model habitats to investigate the effect of landscape factors and local factors on species richness of plants, flower morphologies and plants with fleshy fruits. Additively, I analysed the effect of surrounding landscape and local openness on the functions; pollination success, biological pest control of aphids and seed predation on midfield islets. One of my studies showed that spatial distribution and size of the habitat affected plant species richness. Larger habitat size and higher connectivity between habitats increased species richness of plants in the habitats. Openness of the habitats was shown to be an important factor to increase species richness and richness of flower morphologies, both on midfield islets and in forest borders. Even though midfield islets had the highest species and morphology richness, both habitat types are needed for habitat complementary as forest borders have more plants with fleshy fruits and a higher richness of plant species that flowers in spring/early summer. It was also shown that a more complex forest border, not just with gaps in the canopy, but also with high variation in tree stem sizes increases plant species richness in the field layer. The conclusion is that by managing small remnant habitats to remain or become more semi-open and complex in their structure, would increase species richness of plants, grassland specialist species, and flower morphologies. It would also increase some ecosystem functions as seed predation and biologic pest control of aphids are more effective close to trees. If both midfield islets and forest borders would be managed to be semi-open, the area and connectivity of semi-open habitat would increase in the agricultural landscape, which may also improve pollination success as the connectivity between populations has a possibility to increase. Grassland specialist species are clearly abundant in the small remnant habitats. As the decline of semi-natural grasslands is causing a decline in grassland specialists’ species, not only plants, I recommend that small remnant habitats are included in conservation and management plans and strategies to improve habitat availability and connectivity for grassland species in agricultural landscapes.Research funder Ekoklim. Project:4339602.
At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.
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Seide, Mariana Figur. "Dinâmica territorial e socioeconômica na região do entorno das Usinas Hidroelétricas Canoas I e II (PR/SP) e as relações com a piscicultura local." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-17112015-110323/.
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Transformações nas condições de vida da Terra fazem parte da nossa história evolutiva. Atualmente, as ações humanas provocam impactos tão intensos que já se considera que estamos marcando uma nova era geológica, o Antropoceno. As alterações globais de origem antropogênica estão relacionadas ao nosso modo de vida moderno e modelo de consumo, assim como ao crescimento demográfico, econômico, agropecuário, industrial que tem demanda crescente por recursos. Todos esses fatores apresentam potenciais efeitos comprometedores às funções ecossistêmicas e dos bens e serviços ambientais. Neste contexto, os sistemas aquáticos continentais, são significativamente impactados pela construção de barragens. As represas envolvem inúmeras transformações ambientais e ecológicas, sociais e econômicas. Já as regiões do seu entorno podem ser beneficiadas com a utilização das águas represadas. Entender a dinâmica da cobertura e uso do solo e analisar se há a abertura de oportunidade para o desenvolvimento de novas atividades econômicas, aproximam a compreensão dos seus impactos como base para a gestão desses ambientes. O objetivo geral desse trabalho foi analisar a influência das Usinas Hidrelétricas Canoas I e II nos municípios do seu entorno, a partir da analise espaço-temporal das mudanças no uso e cobertura do solo e das dinâmicas socioeconômicas relacionadas ao desenvolvimento das atividades de piscicultura. Os resultados obtidos caracterizam as atividades agropastoris da região como a maior força das dinâmicas ambientais e socioeconômicas. A extrema fragmentação da vegetação nativa é a mais importante consequência ecológica desse processo. Já em termos sociais e econômicos às mudanças no perfil da agricultura geraram a urbanização e o exôdo rural, marginalizando pequenos agricultores. A construção dos barramentos de Canoas I e II teve influência na composição da paisagem após a perda, principalmente de terras agrícolas e coincidiu com o aumento das áreas de urbanização, associada a um aumento da área dos fragmentos da cobertura vegetal nativa e um melhora no índice de proximidade, indicando maior conexão entre os mesmos. Para os entrevistados na pesquisa os reservatórios representam uma oportunidade de desenvolvimento da piscicultura, que já desperta interesse na população como a atividade econômica. Mas, há dificuldades a serem superadas para que se concretizem as expectativas de aproveitamento das águas represadas.Transformations in Earth life conditions are part of our evolutionary history. Currently human activities result in impacts of such magnitude that it has been proposed and widely accepted that we are entering a new geologic era, the Anthropocene. Human induced global changes are related to our modern way of life and the consumption model, as well as to demographic, economic, agricultural and industrial growth, that have an increasing resources demand. All these factors have potential compromising effects on ecosystems functions and good and services that they provide. Furthermore, fresh water ecosystems are highly impacted by river dams. These impoundments involve innumerous environmental and ecological, social and economic transformations, while surrounding areas can benefit from its water use. Understand the land use and cover dynamic and analyze if there are opportunities for new economic activities level the comprehension of their impacts for further environmental management. The overall objective of this study was to analyze the Hydroelectric Power Canoas I and II influence on the watershed counties, by a couple analysis of the spatial and temporal land use changes and the related socio-economic dynamic related to fish farming activities development. Our results show that agriculture and cattle ragging are the main driver of environmental and socio-economic behavior. An extreme native vegetation fragmentation was the most important ecological consequence of this process. In term of social and economic aspects, changes in the agricultural profile lead to an urbanization and rural exodus, marginalizing small framers. The constructions of Canoas I and II dams resulted in losses of agricultural lands, which was associated with an urban sprawl and an area increase of native vegetation patches and proximity index, indicating that they became more connected. For the interviewed local people. The dams represent an opportunity for fish farm developing, since it arouses interest in the population as an economic activity. However, there are difficulties to be overcame to meet the expectation of the impounded waters use.
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Akhtar, Maqbool. "Competition analysis, nitrogen response and canopy cover assessment in sugarcane intercropping systems." Thesis, 1995. http://hdl.handle.net/10125/9268.
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