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1
Kaur, K., R. K. Jalota, D. J. Midmore, and J. Rolfe. "Pasture production in cleared and uncleared grazing systems of central Queensland, Australia." Rangeland Journal 27, no. 2 (2005): 143. http://dx.doi.org/10.1071/rj05012.
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Clearing land of trees and introducing exotic pastures to enhance pasture and cattle production and hence enterprise financial performance are widely practised in Queensland. The results from many previous studies on tree clearing have emphasised the gains in pasture production, but over periods of less than 10–15 years after clearing. The present study questioned the sustainability of pasture production in cleared systems over a longer time-frame (>10 years of clearing). For this, three different age groups of clearing i.e. 5 year, 11–13 year and 33 year were selected in each of 3 major types of tree communities i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla in central Queensland. Paired comparisons of cleared and uncleared (intact) pasture systems were selected for each age group of clearing. The results suggest that the initial gains in pasture production upon clearing were compatible with published studies. However, for longer periods of time since clearing, the gains in pasture production were not sustained and were accompanied by risks of land degradation and loss of pasture plant diversity. For E. populnea and A. harpophylla, the maximum benefits from clearing were achieved at 13–15 years whereas for E. melanophloia, any benefits existed only over a short period of 5–6 years. The study emphasises that each tree community exhibits a specific response with regard to the duration of increased pasture production following clearing. To estimate the total benefits from tree clearing in pasture development, it is important to consider both monetary benefits and non-monetary losses from clearing for different types of tree communities.
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Raich, James W., and Gong Wooi Khoon. "Effects of canopy openings on tree seed germination in a Malaysian dipterocarp forest." Journal of Tropical Ecology 6, no. 2 (May 1990): 203–17. http://dx.doi.org/10.1017/s0266467400004326.
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ABSTRACTThe germination of 43 tree species native to the lowland forests of Malaysia was monitored on forest soil in trays placed in closed-canopy forest, an artificial forest gap, and a large clearing. Germination varied significantly among habitats, with only seven species germinating well in all three sites. Seed germination of most species demonstrated clear patterns of shade tolerance or intolerance identical to those long recognized for tree seedlings. Favoured locations for germination were similar to known distributional patterns of adult individuals in mature and secondary forests. Most forest canopy species germinated in the gap, but germination in the large clearing was dramatically reduced or nil; the regeneration of these species in large clearings will be severely retarded even when seeds are present. Canopy-induced inhibition of germination was apparent in several pioneer species; seeds moved from the forest into the gap or clearing germinated rapidly. Results indicate that natural treefall gaps do not inhibit the germination of most species, but do allow pioneer species to germinate, and therefore regenerate. Although germination occurred in all three locations, the level of germination for particular species varied greatly among habitats. We conclude that germination requirements play a very important role in controlling the species composition of regeneration in forest understorey, gap, and large clearing habitats.
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Scanlan, J. C. "Some aspects of tree-grass dynamics in Queensland's grazing lands." Rangeland Journal 24, no. 1 (2002): 56. http://dx.doi.org/10.1071/rj02003.
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This review examines the interactions between grasses and trees that are relevant to Queensland's grazing lands. Soils and climate determine the potential amount of woody vegetation within an area and clearing, fire and grazing management can modify that potential. In general, the presence of non-leguminous trees reduces the potential grass production beneath their canopy and within woodland patches. Some non-native leguminous trees (e.g. Indian siris, Albizia lebbeck) enhance production of grasses beneath their canopies, whereas the widespread native leguminous trees, mulga (Acacia aneura) and brigalow (A. harpophylla) have not been reported to enhance grass production in the same way. At the patch scale, pasture production beneath woodlands with moderate to high tree basal areas is generally less than in open patches under the same soil and climatic conditions. At a landscape level, tree density, rainfall amount and distribution, and soil type modify pasture production within forest/woodland/shrubland systems. Grasses can reduce tree seedling survival but have little impact on mature woody plants, apart from providing fuel to carry a fire. Modelling studies have been used to examine some aspects of tree-grass production. Firstly, the relationship between grass production and an increasing amount of trees can vary from linear decrease, to exponential decrease to initial stimulation followed by a decrease, depending solely on the relative strengths of stimulatory and competitive effects of trees on grasses. Secondly, simulated pasture production within woodlands shows that the pasture production may be up to 50% higher in paddocks that have high variability in the distribution of those trees compared with areas where trees are uniformly distributed. This is due to the non-linear (negative exponential) relationship between pasture production and tree density that is commonly observed within Queensland. Lastly, simulation studies show that total aboveground production (trees and pasture) of mulga woodland increases as the number of trees per hectare increases. The pasture production response to tree clearing or tree planting depends on tree species, rainfall, soil type, climatic history and post-clearing management including fire and grazing, and will change with time since clearing. The greatest relative increase in pasture production following the removal of woody vegetation occurs: when the initial tree basal area is highest; where rainfall is evenly distributed though the year and on fertile soils with a low water holding capacity.
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Dobner Jr., Mário, Crysttian Arantes Paixão, Emanuel Arnoni Costa, and Cesar Augusto Guimarães Finger. "EFFECT OF SITE AND COMPETITION ON DIAMETER GROWTH OF Araucaria angustifolia." FLORESTA 49, no. 4 (September 19, 2019): 717. http://dx.doi.org/10.5380/rf.v49i4.58161.
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Although the historical interest in using the wood of Araucaria angustifolia, it is still little known concerning the factors that affect the growth. A broader understanding in this context might contribute to the development of appropriate management systems, thus increasing the productivity of plantations and, consequently, the interest in commercially using this species. The present study was based on monospecific populations established in different site conditions (Site Indices between 18-24) where individuals (n=654) were submitted to different competition levels. With the aid of multiple regression techniques, the factors that significantly affected the accumulated growth in diameter of the trees after 20 years of intervention were determined. For the set formed by all trees, 77% of the growth variation can be explained by three factors: site, the proportion of tree diameter at breast height (dbh) of the object tree for analysis in relation to the average dbh of the population before performing the clearings (Cdbh_before) and dominance status in relation to the neighboring trees (Call). The significance of the competition level before the clearing shows that late clearings have limited effects on tree growth. It is concluded that individuals are benefited for having a dominant position in relation to the neighboring trees, reaching diameters 50% larger at the end of the production cycle. Clearings that favour selected trees by removing direct competitors seem to be an interesting management strategy for the species.Keywords: Paraná-pine; Forest Management; Silviculture; Timber Production.
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Cole, Dennis M. "An indirect method for determining the order of expected thinning response among overstocked lodgepole pine stands." Canadian Journal of Forest Research 16, no. 5 (October 1, 1986): 875–79. http://dx.doi.org/10.1139/x86-156.
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Relationships for representing relative thinning response potential among overstocked lodgepole pine stands were investigated with data from 31 stands in four National Forests of Idaho. The common logarithm of mean 10-year cross-sectional increment of dominant and codominant trees on stand edges created by clearing was the dependent variable selected for examining relationships with a large number of tree, stand, and site variables. A linear regression model explained nearly 60% of the variance in the response variable. The model included variables representing mean 10-year periodic cross-sectional increment prior to clearing, site index, and quadratic mean stand diameter. As a predictor of edge-tree response to clearing, the model represents relative thinning response differences to be expected among overstocked lodgepole pine stands and thus reflects relative stand vigor.
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Kennedy, Dan. "From the 1990s: Climbing Around on the Tree of Mathematics." Mathematics Teacher 100, no. 5 (December 2006): 80–85. http://dx.doi.org/10.5951/mt.100.5.0080.
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This September 1995 article approaches creating a modern mathematics curriculum using a metaphoric tree of Mathematics. Author describes problem of optimal selection and sequencing of subjects. He supports the ladder of technology for reaching higher branches of the tree and argues for clearing the dead leaves of centuries of curricular material, clearing the view of beautiful tree of Mathematics.
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Kennedy, Dan. "From the 1990s: Climbing Around on the Tree of Mathematics." Mathematics Teacher 100, no. 5 (December 2006): 80–85. http://dx.doi.org/10.5951/mt.100.5.0080.
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This September 1995 article approaches creating a modern mathematics curriculum using a metaphoric tree of Mathematics. Author describes problem of optimal selection and sequencing of subjects. He supports the ladder of technology for reaching higher branches of the tree and argues for clearing the dead leaves of centuries of curricular material, clearing the view of beautiful tree of Mathematics.
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Dadashazar, Hossein, Ewan Crosbie, Mohammad S. Majdi, Milad Panahi, Mohammad A. Moghaddam, Ali Behrangi, Michael Brunke, Xubin Zeng, Haflidi H. Jonsson, and Armin Sorooshian. "Stratocumulus cloud clearings: statistics from satellites, reanalysis models, and airborne measurements." Atmospheric Chemistry and Physics 20, no. 8 (April 21, 2020): 4637–65. http://dx.doi.org/10.5194/acp-20-4637-2020.
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Abstract. This study provides a detailed characterization of stratocumulus clearings off the US West Coast using remote sensing, reanalysis, and airborne in situ data. Ten years (2009–2018) of Geostationary Operational Environmental Satellite (GOES) imagery data are used to quantify the monthly frequency, growth rate of total area (GRArea), and dimensional characteristics of 306 total clearings. While there is interannual variability, the summer (winter) months experienced the most (least) clearing events, with the lowest cloud fractions being in close proximity to coastal topographical features along the central to northern coast of California, including especially just south of Cape Mendocino and Cape Blanco. From 09:00 to 18:00 (PST), the median length, width, and area of clearings increased from 680 to 1231, 193 to 443, and ∼67 000 to ∼250 000 km2, respectively. Machine learning was applied to identify the most influential factors governing the GRArea of clearings between 09:00 and 12:00 PST, which is the time frame of most rapid clearing expansion. The results from gradient-boosted regression tree (GBRT) modeling revealed that air temperature at 850 hPa (T850), specific humidity at 950 hPa (q950), sea surface temperature (SST), and anomaly in mean sea level pressure (MSLPanom) were probably most impactful in enhancing GRArea using two scoring schemes. Clearings have distinguishing features such as an enhanced Pacific high shifted more towards northern California, offshore air that is warm and dry, stronger coastal surface winds, enhanced lower-tropospheric static stability, and increased subsidence. Although clearings are associated obviously with reduced cloud fraction where they reside, the domain-averaged cloud albedo was actually slightly higher on clearing days as compared to non-clearing days. To validate speculated processes linking environmental parameters to clearing growth rates based on satellite and reanalysis data, airborne data from three case flights were examined. Measurements were compared on both sides of the clear–cloudy border of clearings at multiple altitudes in the boundary layer and free troposphere, with results helping to support links suggested by this study's model simulations. More specifically, airborne data revealed the influence of the coastal low-level jet and extensive horizontal shear at cloud-relevant altitudes that promoted mixing between clear and cloudy air. Vertical profile data provide support for warm and dry air in the free troposphere, additionally promoting expansion of clearings. Airborne data revealed greater evidence of sea salt in clouds on clearing days, pointing to a possible role for, or simply the presence of, this aerosol type in clearing areas coincident with stronger coastal winds.
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Morris, L. Brian. "Utility Customer Tree Replacement." Arboriculture & Urban Forestry 16, no. 1 (January 1, 1990): 22–23. http://dx.doi.org/10.48044/jauf.1990.007.
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Utilities must prune trees in order to safely deliver electrical power and do It In a reliable manner. The ultimate answer to the ever increasingly difficult task of clearing lines from conflicting tree limbs in the urban setting is to have compatible tree species planted in and near the right-of-way rather than the larger maturing species. Duke Power, like many utilities, has decided to take a pro-active approach to the problem and initiate a customer tree replacement program to aid in procuring the customer's agreement to allow the removal of certain incompatible species.
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Umeghalu, ICE. "AGRICULTURAL LAND CLEARING IS IMPERATIVE FOR A SUCCESSFUL AGRICULTURAL MECHANIZATION PROGRAM IN NIGERIA." Agrobiological Records 10 (2022): 42–50. http://dx.doi.org/10.47278/journal.abr/2022.025.
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The rapid increase in population in Nigeria calls for an increase in agricultural production. Farming commences with land clearing. Traditionally, the manual land clearing method is still predominant in Nigeria, where the matchet, hoe and axe are the implement used for the operation. However, this land clearing method can no longer keep pace with the population explosion. The method is ideal for small areas of land with small trees and stumps when surplus labor is available; however, the manual method becomes tedious and costly for mechanized farming. Agricultural land clearing involves removal of natural vegetation from the land, stumping, mechanized tree knockdown, windrowing, wood-cutting and burning, removal of debris and pioneer plowing. The soil structures, crop nutrients, and soil moisturizing content crops need to grow are in the topsoil. Therefore, agricultural land clearing operations should aim at minimum topsoil disturbance-poorly cleared land results in poor yield and frequent damage to agricultural machines and equipment. To achieve adequate agricultural land clearing, special techniques, machines, tools, experienced machine operators, and adequate timing of land clearing operations are necessary. This review aims to offer information on adequate methods of agricultural land clearing, outlining the procedures to be followed, tools to employ and good timing for carrying out various stages of land clearing operations in different agricultural zones of Nigeria. Parameter for assessing good agricultural land clearing is also discussed.
11
A. Ludwig, John, Robert W. Eager, Adam C. Liedloff, Juliana C. McCosker, David Hannah, Nicole Y. Thurgate, John C. Z. Woinarski, and Carla P. Catterall. "Clearing and grazing impacts on vegetation patch structures and fauna counts in eucalypt woodland, Central Queensland." Pacific Conservation Biology 6, no. 3 (2000): 254. http://dx.doi.org/10.1071/pc000254.
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There is national and international concern that tree clearing and cattle grazing reduce habitat for native fauna. In this paper we quantify how the degree of clearing and the level of grazing change the patch structure and composition of vegetation in eucalypt woodlands, and how these habitat changes affect counts for 10 species including birds, reptiles and small mammals. These species were selected because they were abundant, hence providing the data needed for ordinations and regressions. We studied 37 sites occurring in two regions of central Queensland: Blackwater/Emerald and Alpha/Jericho. On each site, indices for the degree of tree clearing and the level of livestock grazing were assessed, the cover and size of tree groves, shrub thickets, log hummocks, termite mounds and perennial grass clumps were measured, and abundances of 10 common vertebrate species were estimated. As expected, the cover and size of tree groves declined and the cover of grass clumps increased as the degree of clearing increased. Native grass composition changed to introduced Buffel Grass as the level of grazing increased. Clearing affected fauna counts more than grazing did. The Grey Butcherbird Cracticus torquatus, Yellow-throated Miner Manorina flavigula, Striated Pardalote Pardalotus striatus and Pale-headed Rosella Platycercus eximius had significantly lower counts on cleared sites, but the Red-backed Fairy-wren Malurus melanocephalus had higher counts. The introduced House Mouse Mus musculus also had higher counts on cleared sites, but Carnaby's Skink Cryptoblephrus carnabyi had lower counts. Counts of the Weebill Smicrornis brevirostris, Bynoe's Gecko Heteronotia binoei and the Delicate Mouse Pseudomys delicatulus did not significantly change with clearing. Counts for the Pale-headed Rosella increased as the level of grazing increased, but counts for the other fauna species did not significantly change with our grazing index. Except for Bynoe's Gecko, fauna counts significantly changed with various vegetation patch attributes, particularly those strongly affected by clearing. From these results, we know which of the 10 fauna species are likely to decline or increase with clearing and grazing, and this knowledge can be used by land managers.
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Gowen, Rebecca, and Steven G. Bray. "Bioeconomic modelling of woody regrowth carbon offset options in productive grazing systems." Rangeland Journal 38, no. 3 (2016): 307. http://dx.doi.org/10.1071/rj15084.
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Agricultural land has been identified as a potential source of greenhouse gas emissions offsets through biosequestration in vegetation and soil. In the extensive grazing land of Australia, landholders may participate in the Australian Government’s Emissions Reduction Fund and create offsets by reducing woody vegetation clearing and allowing native woody plant regrowth to grow. This study used bioeconomic modelling to evaluate the trade-offs between an existing central Queensland grazing operation, which has been using repeated tree clearing to maintain pasture growth, and an alternative carbon and grazing enterprise in which tree clearing is reduced and the additional carbon sequestered in trees is sold. The results showed that ceasing clearing in favour of producing offsets produces a higher net present value over 20 years than the existing cattle enterprise at carbon prices, which are close to current (2015) market levels (~$13 t–1 CO2-e). However, by modifying key variables, relative profitability did change. Sensitivity analysis evaluated key variables, which determine the relative profitability of carbon and cattle. In order of importance these were: the carbon price, the gross margin of cattle production, the severity of the tree–grass relationship, the area of regrowth retained, the age of regrowth at the start of the project, and to a lesser extent the cost of carbon project administration, compliance and monitoring. Based on the analysis, retaining regrowth to generate carbon income may be worthwhile for cattle producers in Australia, but careful consideration needs to be given to the opportunity cost of reduced cattle income.
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Mayer, Thomas. "Distribution Tree Clearance Program at Baltimore Gas and Electric." Arboriculture & Urban Forestry 11, no. 2 (February 1, 1985): 40–44. http://dx.doi.org/10.48044/jauf.1985.010.
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The Baltimore Gas and Electric Company's tree-clearance policy is to provide for the safe and reliable supply of electric energy in an economic manner which is compatible with the environment. To that end, the Distribution Tree Clearance Program utilizes many methods and techniques to trim trees and shrubs and to maintain line integrity. Natural trimming is preferred, as is selective clearing with appropriate treatment with an EPA-approved herbicide. Following the introduction of an aggressive "Think Cut Down" program, more trees are being removed from the system, thus reducing future maintenance time. Often, where undesirable tree species are cut down, an aesthetically pleasing grass-herb-shrub-desirable tree species community becomes established.
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Bortolussi, G., J. G. McIvor, J. J. Hodgkinson, S. G. Coffey, and C. R. Holmes. "The northern Australian beef industry, a snapshot. 5. Land and pasture development practices." Australian Journal of Experimental Agriculture 45, no. 9 (2005): 1121. http://dx.doi.org/10.1071/ea04013.
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The land and pasture development practices of 375 northern Australian beef properties in 8 regions were surveyed during 1996–97. These properties represented a broad cross-section of the beef industry in terms of geographical location, enterprise and herd size, and ownership structures. Both tree clearing and killing were more common in Queensland than in the Northern Territory or northern Western Australia. In all regions where trees were poisoned, native pasture was more widely used than sowing introduced grass and/or legume species. In contrast, tree clearing was most often accompanied by sowing pastures (either an introduced grass only or introduced grass and legume species together), rather than using native pastures. Central coastal Queensland had the highest use of poisoning trees for pasture development. Tree clearing and using native pasture was most important in central Queensland regions and the Maranoa South West. Sowing introduced pasture species under live trees was more commonly practiced in northern Queensland, the Northern Territory and northern Western Australia than in other regions. A considerable number of introduced grass and legume species were sown by producers. Most of the sown species were grasses. Many of the sown grass and legume species were spreading naturally. Buffel grass was spreading in all areas with < 1000 mm average annual rainfall, but most sown species were spreading only in wetter regions. Stylosanthes spp. were the most commonly spreading legume species in regions with > 500 mm average annual rainfall. The results are discussed in relation to contemporary natural resource management issues and how this may affect land and pasture development activities in the future.
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Rolfe, J., R. Blamey, and J. Bennett. "Valuing the preservation of rangelands: Tree clearing in the desert uplands region of Queensland." Rangeland Journal 22, no. 2 (2000): 205. http://dx.doi.org/10.1071/rj0000205.
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Tree clearing to improve pasture production for beef cattle is becoming more commonplace in the rangeland zone in Queensland. In parts of the Desert Uplands region of Central Queensland, current clearing rates are among the highest in Australia. The state government, in granting permits for clearing, has to balance the improved production benefits, accruing mostly to pastoralists, against the biodiversity losses, which are borne more widely by Australian society. In the current debate over clearing restrictions, little information exists about the values that society may hold for the preservation of rangelands. To address this deficiency, a choice modelling study was undertaken to provide estimates of the benefits of retaining remnant vegetation that are appropriate for inclusion in a benefit cost analysis of tighter clearing restrictions. Attributes included in the choice model were reductions in the population size of non-threatened species and unique ecosystems, the number of endangered species lost to the region, and changes in regional income and employment. The benefits estimated for individual attributes, and for some more restrictive policy settings are reported. Key words: remnant native vegetation, economic valuation, grazing industry, pasture development, choice modelling
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Ouattara, Tiodionwa Abdoulaye, Valère-Carin Jofack Sokeng, Irié Casimir Zo-Bi, Koffi Fernand Kouamé, Clovis Grinand, and Romuald Vaudry. "Detection of Forest Tree Losses in Côte d’Ivoire Using Drone Aerial Images." Drones 6, no. 4 (March 25, 2022): 83. http://dx.doi.org/10.3390/drones6040083.
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The fight against deforestation and forest degradation is now a major challenge for the preservation of global forest ecosystems. The remote sensing forest monitoring methods that are currently deployed are not always adapted to the Ivorian context because of the high cloud cover, diversity of shaded crops, and land clearing techniques. This study proposes a drone-based approach to assess intra-annual tree losses in the Bossématié classified forest. The method used is based on a detection analysis of tree losses in forest areas from a time series of aerial images acquired by drones from November 2018 to April 2019 on five sites in the studied forest. Based on photogrammetric models and photointerpretation, tree heights and tree crown sizes were estimated. Then, tree losses were detected based on the variation of tree heights during the study period. An analysis of the distribution of tree heights in Bossématié classified forest reveals that the maximum tree height was 65.06 m in November 2018 and 64.07 m in April 2019 with an average tree height of 34.29–37.00 m in November 2018 and 34.63–36.88 m in April 2019. The average tree crown area, meanwhile, was estimated to be 152 m². With an estimation accuracy of about 97%, these tree structural data indicate a minimum loss of 107 trees corresponding to a clearing area of 2 ha across all the surveyed sites from November 2018 to April 2019. This forest monitoring approach shows a considerable local loss of biodiversity and should be involved in the implementation of preservation, rehabilitation, and deployment strategies in an operational deforestation monitoring system in Côte d’Ivoire.
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Shibuya, S., K. Kubota, and M. Ohsawa. "Effects of small-scale management on biodiversity of an abandoned coppice forest in Japan: a case study on vegetation regeneration and ground beetle community." Web Ecology 8, no. 1 (November 19, 2008): 116–24. http://dx.doi.org/10.5194/we-8-116-2008.
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Abstract. We studied the effects of small-scale vegetation disturbances on biodiversity in an abandoned coppice forest in central Japan during 2004–2006. We assessed biodiversity by examining vegetation regeneration and by changes in the diversity and abundance of ground beetles after experimental manipulations including tree felling, vegetation clearing, and litter removal. Our experimental design was dictated by the need of producing only small disturbances; therefore we could not replicate plots. Instead, we used a repeated measures approach during three years to document the consistency of experimental effects. We found that the diversity of regenerating vegetation increased dramatically due to recruitment of many new species after clearing ground vegetation. Tree cutting caused strong environmental changes and affected vegetation regeneration rate but not diversity. Tree cutting also significantly increased the diversity of ground beetle species, while litter removal affected the abundance of ground beetles. Our results suggest that a sound conservation practice shall combine tree cutting with ground vegetation clearing and litter removal. Besides, conservation of abandoned forests may be based on low-intensity labor, including tree cutting on restricted areas. Finally, ground beetles appeared to be surprisingly sensitive to vegetation disturbance on a restricted area and thus can be suggested for monitoring such small-scale-disturbance-based conservation practices.
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Zhao, Zeyu, and John P. Dickerson. "Clearing Kidney Exchanges via Graph Neural Network Guided Tree Search (Student Abstract)." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 10 (April 3, 2020): 13989–90. http://dx.doi.org/10.1609/aaai.v34i10.7267.
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Kidney exchange is an organized barter market that allows patients with end-stage renal disease to trade willing donors—and thus kidneys—with other patient-donor pairs. The central clearing problem is to find an arrangement of swaps that maximizes the number of transplants. It is known to be NP-hard in almost all cases. Most existing approaches have modeled this problem as a mixed integer program (MIP), using classical branch-and-price-based tree search techniques to optimize. In this paper, we frame the clearing problem as a Maximum Weighted Independent Set (MWIS) problem, and use a Graph Neural Network guided Monte Carlo Tree Search to find a solution. Our initial results show that this approach outperforms baseline (non-optimal but scalable) algorithms. We believe that a learning-based optimization algorithm can improve upon existing approaches to the kidney exchange clearing problem.
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Yu Prosekov, A., A. O. Rada, A. D. Kuznetsov, A. E. Timofeev, and M. A. Osintseva. "Development of a Software Package for Digital Forest Inventory Based on Aerial Photography Data." IOP Conference Series: Earth and Environmental Science 981, no. 4 (February 1, 2022): 042017. http://dx.doi.org/10.1088/1755-1315/981/4/042017.
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Abstract When clearing protective strips for linear infrastructure such as power lines, it is important to minimize tree felling. The purpose of the study is to develop and test a software package for digital forest inventory of tree and shrub vegetation in the zones of linear infrastructure facilities. In the study, a software package for digital forest inventory based on aerial photography with UAVs was developed and tested, based on the methods of multilayer perceptron and a self-organizing network based on competition (Kohonen network). The approbation has shown that it allows to accurately identifying the presence and height of trees and shrubs in the protection zones, to obtain precise coordinates for planning clearing works. At present, the areas of the territory where it is necessary to remove trees and shrubs are determined manually with an overestimation of 25-50%. Therefore, the use of a software package for digital forest inventory allows you to save up to 0.8 hectares of trees and shrubs per 1 kilometre of the length of the power transmission line, as well as save about 27 thousand rubles (about 375 US dollars) per 1 kilometre during work.
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Pertiwi, Dina, Rahmat Safe'i, Hari Kaskoyo, and Indriyanto Indriyanto. "IDENTIFIKASI TIPE KERUSAKAN POHON MENGGUNAKAN METODE FOREST HEALTH MONITORING (FHM)." PERENNIAL 15, no. 1 (July 8, 2019): 1. http://dx.doi.org/10.24259/perennial.v15i1.6033.
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Trees are an important part of the compilation of forest ecosystems blocks of collections of plants and/or animals, Wan Abdul Rachman Forest Park, Lampung Province. Block collection of plants and or animals serves as a place for collecting, protecting and preserving biodiversity. The problems that occur in this block are changes in forest areas, initially primary forests become mixed forests due to land clearing. Land clearing causes various types of tree damage which causes a decrease in tree health and forest health, so it is necessary to identify tree damage conditions. The purpose of the study was to determine the condition of tree damage based on the location of tree damage, type of tree damage and severity. Identification is carried out using the Forest Health Monitoring (FHM) method, the measurement parameter is the condition of tree damage. The study was conducted in June 2018 in a collection block of plants and / or animals Tahura WAR Kelurahan Sumber Agung, Kemiling, Bandar Lampung covering 141.18 ha. The sampling intensity used was 2.30%, data collection was carried out in eight FHM cluster clusters. Based on the results of the study there were 144 individual trees that were damaged. The location of damage occurs mostly in the roots and the lower part of the stem is 29%, the lower stem is 18% and the branches are 15%. There were 11 types of damage observed with the largest type of damage, namely open wounds by 46%, broken or dead branches by 17%, cancer by 9% and leaves, shoots or shoots damaged by 9%. The most severe severity is found in the severity of 20% with a percentage of 39%, severity of 30% with a percentage of 35% and severity of 40% with a percentage of 7%.
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Parro, Kristi, Marek Metslaid, Getter Renel, Allan Sims, John A. Stanturf, Kalev Jõgiste, and Kajar Köster. "Impact of postfire management on forest regeneration in a managed hemiboreal forest, Estonia." Canadian Journal of Forest Research 45, no. 9 (September 2015): 1192–97. http://dx.doi.org/10.1139/cjfr-2014-0514.
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Fire is a significant agent for the development of boreal and hemiboreal forests, altering soil and light conditions, affecting seedbanks, and removing seed trees. Burned areas should be managed with care, as inappropriate techniques prolong the regeneration period and reduce the diversity and resilience of stands to disturbances. To study the effects of fire and postfire management on the successional changes in regeneration abundance, species composition and tree height sample plots were established in sandy pine forests in northwestern Estonia on areas burned 2 or 22 years ago. Five types of sample plots were established: (i) areas without fire damage, (ii) burned uncleared areas, (iii) burned forest areas cleared after forest fire, (iv) burned uncleared areas with live trees, and (v) burned uncleared areas with dead trees. Three main tree species common to hemiboreal forests were analyzed: Betula spp., Pinus sylvestris L., and Populus tremula L. Results showed that clearing burned areas after wildfire significantly reduced the abundance of regeneration compared with burned uncleared areas but favored height growth of P. sylvestris in later development. To regenerate and maintain mixed stands after wildfire, retaining some residual trees can facilitate regeneration compared with complete clearing, although a dense stand with live trees or a large amount of deadwood can hinder regeneration.
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Williams, John, E. N. Bui, E. A. Gardner, Mark Littleboy, and M. E. Probert. "Tree clearing and dryland salinity hazard in the Upper Burdekin Catchment of North Queensland." Soil Research 35, no. 4 (1997): 785. http://dx.doi.org/10.1071/s96083.
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This paper provides experimental data on the effect of tree clearing, introduction of perennial Stylosanthes based pastures, and the use of native grasses on the water balance of a red earth soil in the Upper Burdekin Catchment near Charters Towers. The water balance simulation models SWIM and PERFECT are used to extend the results and estimate deep drainage for this and other soils in this tropical environment. The analysis illustrates that the soil/climate interaction in the wet/dry tropics has a similarity with the winter-dominant rainfall zone where vegetation change can substantially increase deep drainage beyond the root-zone. Salt distribution in the soil/landscapes of the Upper Burdekin suggests that there is a salinity hazard, should a significant shift in the water balance occur as a result of tree clearing. Therefore, in the Upper Burdekin Catchment of North Queensland, indiscriminate tree clearing is a hazardous form of land management and should only proceed after the risks of dryland salinity have been evaluated and shown to be negligible.
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Hall, Trevor J., Paul Jones, Richard G. Silcock, and Piet G. Filet. "Pasture production and composition response after killing Eucalypt trees with herbicides in central Queensland." Rangeland Journal 38, no. 5 (2016): 427. http://dx.doi.org/10.1071/rj16013.
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Clearing woodlands is practised worldwide to increase crop and livestock production, but can result in unintended consequences including woody regrowth and land degradation. The pasture response of two eucalypt woodlands in the central Queensland rangelands to killing trees with herbicides, in the presence or absence of grazing and regular spring burning, was recorded over 7 or 8 years to determine the long-term sustainability of these common practices. Herbage mass and species composition plus tree dynamics were monitored in two replicated experiments at each site. For 8 years following herbicide application, killing Eucalyptus populnea F. Muell. (poplar box) trees resulted in a doubling of native pasture herbage mass from that of the pre-existing woodland, with a tree basal area of 8.7 m2 ha–1. Conversely, over 7 years with a similar range of seasons, killing E. melanophloia F. Muell. (silver-leaved ironbark) trees of a similar tree basal area had little impact on herbage mass grown or on pasture composition for the first 4 years before production then increased. Few consistent changes in pasture composition were recorded after killing the trees, although there was an increase in the desirable grasses Dichanthium sericeum (R. Br.) A. Camus (Queensland bluegrass) and Themeda triandra Forssk. (kangaroo grass) when grazed conservatively. Excluding grazing allowed more palatable species of the major grasses to enhance their prominence, but seasonal conditions still had a major influence on their production in particular years. Pasture crown basal area was significantly higher where trees had been killed, especially in the poplar box woodland. Removing tree competition did not have a major effect on pasture composition that was independent of other management impositions or seasons, and it did not result in a rapid increase in herbage mass in both eucalypt communities. The slow pasture response to tree removal at one site indicates that regional models and economic projections relating to tree clearing require community-specific inputs.
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Sangha, Kamaljit K., Rajesh K. Jalota, and David J. Midmore. "Litter production, decomposition and nutrient release in cleared and uncleared pasture systems of central Queensland, Australia." Journal of Tropical Ecology 22, no. 2 (February 1, 2006): 177–89. http://dx.doi.org/10.1017/s0266467405003020.
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The temporal impact of clearing trees on litter production, litter decomposition and on C, N and P release through decomposition of litter was examined in the pasture systems of a semi-arid zone of central Queensland. Paired sites for cleared pastures (developed from clearing woodlands) and uncleared (intact woodland) pastures were selected to represent three dominant tree communities of the region i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla, with three different time-since-clearing (5, 11–13 and 33 y) treatments. Yearly litter production was greater at uncleared sites (1732–1948 kg ha−1 y−1 for eucalypt and 2596 kg ha−1 y−1 for acacia communities) compared with cleared sites (1038–1282 kg ha−1 y−1 for eucalypt and 1100 kg ha−1 y−1 for acacia communities averaged over three time-since-clearing treatments). Rates of litter decomposition and of release of C, N and P from decomposing litter were higher at cleared than uncleared sites for all three tree communities. The cleared and uncleared sites did not differ significantly in total amount of C and N released per year since the concentrations of C and N were greater in litter from uncleared sites but the rate of release was less than that at cleared sites. Slow but continuous release of nutrients in eucalypt and acacia woodlands may be an adaptation of these communities to maintain the nutrient cycle and to avoid leaching of nutrients in the nutrient-poor soils of the region.
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Bella, I. E. "Tree Growth Response Along Seismic Lines in Alberta." Forestry Chronicle 62, no. 1 (February 1, 1986): 29–34. http://dx.doi.org/10.5558/tfc62029-1.
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Stem growth data from breast height were collected from about 2000 trees on 192 sample transects (plots) located adjacent to seismic lines. Sampled stands represented the most important forest cover types between 10 and 100 years of age over a range of site conditions in the foothills of western Albetra from Rocky Mountain House to Grande Prairie. Line clearing stimulated breast height radial increment fairly consistently in the 20% range of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) B.S.P.) trees. This improvement expressed in terms of stand growth, however, fell far short of that required to make up for the loss of wood production over these lines if the cut trees are not utilized. The lack of significant stimulation from line clearing in aspen (Populus tremuloides Michx.) stands indicates a complete loss of production due to the lines.
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Porteck, Kevin, Ansel Miller, and Donald Ham. "Comparison of Alternative Maintenance Treatments for an Electric Transmission Right-Of-Way on Steep Mountainous Terrain." Arboriculture & Urban Forestry 21, no. 3 (May 1, 1995): 168–74. http://dx.doi.org/10.48044/jauf.1995.027.
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A study has been initiated to evaluate some alternative vegetation managementtechniques on an electrical transmission right-of-way in the Blue Ridge Mountains of North Carolina. Three years after right-of-way clearing, fourtreatments and a control were blocked on south-facing slopes at three locations. The treatments consisted of 1) clearcutting by chainsaw, 2) a selective low-volume basal application of herbicide to tall-growing species, 3) clearcutting followed by a selective application of a tree growth regulator to cut stumps, and 4) clearcutting followed by a nonselective application of a tree growth regulator to cut stumps. After two growing seasons, mean tree heights for the chainsaw clearing and selective herbicide treatments were not significantly different from the untreated control. Treatments consisting of chainsaw clearing followed by application of a growth regulator provided the lowest mean tree height. However, areas treated with a growth regulator exhibited the largest increase of undesirable tallgrowing tree seedlings. The chainsaw cutting treatment resulted in the greatest mean height for those species considered to be undesirable components of a right-of-way plant community, and yielded the largest number of sprouting stumps with the highest average number of sprouts per stump. Although the long-term treatment effects cannot clearly be determined after two growing seasons, the selective low-volume basal herbicide method has produced a tendency toward increasing the relative dominance of desirable species within the right-of-way.
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Harms, B. P., R. C. Dalal, and A. P. Cramp. "Changes in soil carbon and soil nitrogen after tree clearing in the semi-arid rangelands of Queensland." Australian Journal of Botany 53, no. 7 (2005): 639. http://dx.doi.org/10.1071/bt04154.
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Changes in soil carbon (C) and nitrogen (N) stocks following tree clearing were estimated at 32 rangeland sites in central and southern Queensland by using paired-site sampling. When corrected for soil bulk-density differences at each site, average soil C across all sites decreased after tree clearing by 8.0% for 0–0.3-m soil depth, and by 5.4% for 0–1.0-m depth; there were corresponding declines in soil C of 2.5 and 3.5tha–1, respectively. Mean soil C stocks (excluding surface litter, extractable roots and coarse charcoal) at uncleared sites were 29.5tha–1 for 0–0.3-m soil depth, and 62.5tha–1 for 0–1.0-m depth. Mean soil C stocks (0–0.3m) were 41% of the mean total C for the soil–plant system (soil + litter/woody debris + stand biomass) at uncleared sites. Soil C decline (0–0.3m) accounted for approximately 7% of the average total C lost because of land clearing across all sites. Soil C stocks at uncleared sites were correlated with tree basal area, clay content and soil phosphorus (P) content. Changes in soil C after tree clearing were strongly correlated to initial soil C contents at the uncleared sites, and were associated with particular vegetation groups and soil types. Changes in soil N were strongly correlated with changes in soil C; however, the average change in soil N across all sites was not significant. Given the size of the C and N pools in rangeland soils, the factors that influence soil C and soil N dynamics in rangeland systems need to be better understood for the effective management of C stocks in these soils.
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Han, Qi Long, Zuo Ming Zhu, Xin Gao, and Qi Yun Zhang. "Run Risk Analysis of Solid Rocket Motor Waterjet Clearing System." Applied Mechanics and Materials 483 (December 2013): 660–63. http://dx.doi.org/10.4028/www.scientific.net/amm.483.660.
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According to the hazard identification theory, run risks of solid rocket motor waterjet clearing system were identified from three different angles and potential causes of run risks were investigated; based on analysis of accidents that may occur in the running of solid rocket motor waterjet clearing system, fault tree analysis of propellant combustion/explosion and AP wastewater spill was carried out, minimal cut sets (path sets) and structural importance of each basic event were obtained, and furthermore corresponding recommendations in the accident prevention of solid rocket motor waterjet clearing system running were given accordingly.
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Sangha, Kamaljit K., Rajesh K. Jalota, and David J. Midmore. "Impact of tree clearing on soil pH and nutrient availability in grazing systems of central Queensland, Australia." Soil Research 43, no. 1 (2005): 51. http://dx.doi.org/10.1071/sr03152.
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In Queensland, land is cleared at high rates to develop pastures for enhanced production and the associated monetary gains. However, pasture production declines over time in cleared pastures until a new equilibrium is reached. The present study focussed on elucidating the reasons for decline in pasture production and finding the key soil properties that are affected due to clearing. Paired sites for cleared and uncleared pastures were selected to represent 3 dominant tree communities of the semi-arid tropics in central Queensland, i.e. Eucalyptus populnea, E. melanophloia, and Acacia harpophylla. The cleared pastures were chosen to represent 3 different durations of time since clearing (5, 11–13, and 33 years) to evaluate the temporal impact of clearing on soil properties. Various soil parameters were studied: macronutrients—available N (NH4+and NO3–), total N, and available P; micronutrients—Cu, Fe, Zn, and Mn; exchangeable cations—Ca, Mg, Na, and K (also macronutrients); pHw; and electrical conductivity. Of these, pHw showed a significant response to time of clearing for all 3 tree communities. Soil pHw increased significantly at cleared sites relative to uncleared (native woodland) pastures, and the increase was highly correlated with concentrations of exchangeable Ca, Mg, and Na. The change in soil pHw and exchangeable cations was more evident at >0.30 m soil depth. The increase in soil pHw in cleared pastures decreased the availability of soil nutrients for plant growth and, hence, pasture productivity. The interactions of different soil properties down the profile as a result of changes caused by clearing are important when interpreting the effects of clearing on soil properties.
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Ellis, C. R., J. W. Pomeroy, T. Brown, and J. MacDonald. "Simulation of snow accumulation and melt in needleleaf forest environments." Hydrology and Earth System Sciences 14, no. 6 (June 14, 2010): 925–40. http://dx.doi.org/10.5194/hess-14-925-2010.
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Abstract. Drawing upon numerous field studies and modelling exercises of snow processes, the Cold Regions Hydrological Model (CRHM) was developed to simulate the four season hydrological cycle in cold regions. CRHM includes modules describing radiative, turbulent and conductive energy exchanges to snow in open and forest environments, as well as account for losses from canopy snow sublimation and rain evaporation. Due to the physical-basis and rigorous testing of each module, there is a minimal need for model calibration. To evaluate CRHM, simulations of snow accumulation and melt were compared to observations collected at paired forest and clearing sites of varying latitude, elevation, forest cover density, and climate. Overall, results show that CRHM is capable of characterising the variation in snow accumulation between forest and clearing sites, achieving a model efficiency of 0.51 for simulations at individual sites. Simulations of canopy sublimation losses slightly overestimated observed losses from a weighed cut tree, having a model efficiency of 0.41 for daily losses. Good model performance was demonstrated in simulating energy fluxes to snow at the clearings, but results were degraded from this under forest cover due to errors in simulating sub-canopy net longwave radiation. However, expressed as cumulative energy to snow over the winter, simulated values were 96% and 98% of that observed at the forest and clearing sites, respectively. Overall, the good representation of the substantial variations in mass and energy between forest and clearing sites suggests that CRHM may be useful as an analytical or predictive tool for snow processes in needleleaf forest environments.
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Schmitt, Melissa H., Keenan Stears, Mary K. Donovan, Deron E. Burkepile, and Dave I. Thompson. "Integrating herbivore assemblages and woody plant cover in an African savanna to reveal how herbivores respond to ecosystem management." PLOS ONE 17, no. 8 (August 31, 2022): e0273917. http://dx.doi.org/10.1371/journal.pone.0273917.
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African savannas are experiencing anthropogenically-induced stressors that are accelerating the increase of woody vegetation cover. To combat this, land managers frequently implement large-scale clearing of trees, which can have a cascading influence on mammalian herbivores. Studies rarely focus on how differences in woody cover influence the herbivore assemblage, making it difficult to assess how aggressive measures, or the lack of management, to counteract increasing woody cover affect the local composition and biodiversity of herbivores. We address this knowledge gap by applying a model-based clustering approach to field observations from MalaMala Game Reserve, South Africa to identify multiple herbivore–vegetation ‘configurations,’ defined as unique sets of herbivore assemblages (i.e., groups of herbivores) associated with differing woody plant covers. Our approach delineated how tree-clearing influences the distribution and abundance of the herbivore community in relation to surrounding savanna areas, which represent a natural mosaic of varying woody cover. Regardless of season, both intensively managed areas cleared of trees and unmanaged areas with high tree cover contained configurations that had depauperate assemblages of herbivores (low species richness, low abundance). By contrast, habitats with intermediate cover of woody vegetation had much higher richness and abundance. These results have substantial implications for managing African savannas in a rapidly changing climate.
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Carvalho Jr, J. A., C. A. Gurgel Veras, E. C. Alvarado, D. V. Sandberg, S. J. Leite, R. Gielow, E. R. C. Rabelo, and J. C. Santos. "Understorey fire propagation and tree mortality on adjacent areas to an Amazonian deforestation fire." International Journal of Wildland Fire 19, no. 6 (2010): 795. http://dx.doi.org/10.1071/wf08047.
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Fire characteristics in tropical ecosystems are poorly documented quantitatively in the literature. This paper describes an understorey fire propagating across the edges of a biomass burn of a cleared primary forest. The experiment was carried out in 2001 in the Amazon forest near Alta Floresta, state of Mato Grosso, Brazil, as part of biomass burning experiments conducted in the same area since 1997. The vegetation of a 200 × 200-m2 forested area was clear-cut in early June and burned in late August. The understorey fire that escaped from the main burn was monitored across the four sides of the land clearing area. Flame-front spread varied between 0.14 and 0.35 m min–1. Maximum flame height was about 30 cm and typical flame depth was 10 to 15 cm. Tree mortality was investigated in 2003 in four areas adjacent to the biomass burning experiment. A total of 210 trees were counted in the four areas, 29.5% were dead as a consequence of the understorey fire that had occurred 2 years before. This fire-caused mortality is evidence of the synergistic effect between slash burning, tree mortality and future fire vulnerability on the forest–land clearing interfaces.
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Atangana, Alain R., Juvenal Zahoui Gnangoh, Allegra Kouassi Yao, Thomas d’Aquin Kouakou, Anatole Mian Ndri Nda, and Christophe Kouamé. "Rebuilding Tree Cover in Deforested Cocoa Landscapes in Côte d’Ivoire: Factors Affecting the Choice of Species Planted." Forests 12, no. 2 (February 8, 2021): 198. http://dx.doi.org/10.3390/f12020198.
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Intensive cocoa production in Côte d’Ivoire, the world’s leading cocoa producer, has grown at the expense of forest cover. To reverse this trend, the country has adopted a “zero deforestation” agricultural policy and committed to rehabilitating its forest cover through the planting of high-value tree species in cocoa landscapes using a participatory approach. However, little is known regarding the factors influencing farmers’ introduction of high-value tree species to cocoa landscapes. We tested the hypothesis that ten previously reported factors to influence agroforestry system adoption to predict the number and choice of tree species that farmers introduce to cocoa farms. We interviewed 683 households in the cocoa-producing zone of Côte d’Ivoire and counted tree species on their cocoa farms. On average, two tree species were recorded per surveyed farm. Generalized Poisson regression models revealed that, in the cocoa production area, experience in tree planting and expected benefits, including income and food, influence tree species introduction through planting or “retention” when clearing land for cocoa establishment. The age of the farmer also influenced (p = 0.017) farmers’ tree species planting on cocoa farms. Fewer tree species were introduced into current intensive cocoa-production areas than in “old cocoa-loops” and forested areas. The number of tree species introduced to cocoa farms increased with expected benefits and experience in tree planting. The number of planted tree species also increased with farmers’ age. Tree species were mostly selected for the provision of shade to cocoa, production of useful tree products (38%), and income from the sale of these products (7%). Fruit tree species were the most planted, while timber tree species were mostly spared when clearing land for cocoa production.
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Kaur, Kamaljit, David J. Midmore, Rajesh K. Jalota, and Nanjappa Ashwath. "Pasture composition in cleared and uncleared woodlands." Australian Journal of Botany 54, no. 5 (2006): 459. http://dx.doi.org/10.1071/bt05174.
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Land clearing in Queensland is often practised to enhance pasture production, and hence, increase financial returns from beef production. The benefits of clearing have been quantified in terms of short-term gains in pasture yield but have not adequately accounted for possible medium- or longer-term impediments that may be attributed to clearing. Therefore, impacts of clearing and the subsequent sowing of exotic grasses such as Cenchrus ciliaris L. on pasture composition and production were studied. To achieve this, paired sites were selected representing cleared and uncleared pastures across three different times since clearing (i.e. 5, 11–13 and 33 years since clearing) for the three dominant tree communities of central Queensland (i.e. Eucalyptus populnea F.Muell. (poplar box), E. melanophloia F.Muell. (silver-leaved ironbark) and Acacia harpophylla F.Muell. ex. Benth. (brigalow)). The results demonstrated that species diversity declined with clearing and sowing of exotic pastures. Species diversity and pasture production were negatively related. Although pasture yield was 2–3 times greater 13 years after clearing of E. populnea and A. harpohylla, the gains in pasture yield were not consistent over time, yields being only 1.5 times greater after 33 years of clearing. In E. melanophloia, an increase in the yield of only 1.5–1.8 times occurred 5 years after clearing compared with uncleared pastures, whereas 33 years after clearing, yield was 3/4 of that in uncleared pastures. The initial gains in pasture yield were accompanied by a loss of plant diversity that may affect ecosystem functions such as nutrient cycling or soil mineralisation, and the longer-term production gains.
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Houston, Wayne A., and Alistair Melzer. "Grazing and tree ‘clearing’ alter grass-associated invertebrate assemblages in an Australian tropical grassy woodland." Rangeland Journal 40, no. 6 (2018): 539. http://dx.doi.org/10.1071/rj18062.
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To evaluate the response of invertebrates to ‘clearing’ and grazing pressure impacts, a previously grazed but uncleared grassy woodland in central Queensland was manipulated to provide four grazing pressures (destocked, low, moderate and high) and two tree treatments (with trees, i.e. untreated, and ‘cleared’, i.e. trees and saplings poisoned with herbicides), with two replicates of each, making 16 plots in total. Monitoring was carried out in 1998, approximately four years post-establishment of the treatments. Two types of samples were taken: pitfall for ground-active fauna and suction for grass-associated fauna. Overall, 23 orders of invertebrates were sampled by pitfalls and 22 by suction. Significant effects of grazing on invertebrate assemblages were detected by both methods, but no effects were detected from ‘clearing’. There was a gradation in the invertebrate assemblages from low to high grazing pressure, the invertebrate assemblages in the paddocks with the highest grazing differing most from those in the destocked and low-grazing-pressure paddocks. Notwithstanding the lack of effect of ‘clearing’ at the assemblage level, ground-active invertebrates and some grass-associated invertebrates increased in abundance following ‘clearing’, possibly reflecting an increase in the quality of the resource base. However, ground-active invertebrates and grass-associated invertebrates showed contrasting responses to grazing pressure, the former increasing, possibly reflecting changes in trapability due to the more open vegetation structure at higher grazing pressures. The abundance of grass-associated invertebrates declined by 50–80% with increased grazing – although with complex changes in assemblage structure. Despite those declines, the basic trophic pyramid remained, and, along with that, the potential for recovery of invertebrate assemblages and associated ecosystem services with reduction in grazing intensity. With 80% of Queensland grazed, the reduction in invertebrate abundance has implications for the viability of insectivores, particularly mobile fauna such as birds, at a landscape scale. It is recommended that the utility of using suction samples as a basis for assessing ecosystem functional health be investigated and that grazing pressure be reduced to increase invertebrate assemblages of rangeland pastures and to improve sustainability.
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Fournier, Aude, André Bouchard, and Alain Cogliastro. "Artificial Regeneration of Hardwoods in Early Successional Shrub Communities Using Two Clearing Intensities and Herbicide Application." Northern Journal of Applied Forestry 24, no. 3 (September 1, 2007): 184–91. http://dx.doi.org/10.1093/njaf/24.3.184.
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Abstract In southern Quebec, returning abandoned farmland to forest production presents a management opportunity. The shrub communities, which naturally colonize abandoned agricultural land, could be enriched by planting hardwood species that occurred in the precolonial forests. This study examines the growth of four hardwood species (Acer saccharum, Fraxinus americana, Prunus serotina, and Juglans nigra) planted on former pastures now covered by shrubby vegetation. Retaining part of this shrubby vegetation may produce improved growth in the planted trees. The experimental plantations were established in 1998 in two sites with different soil conditions and consisted of various treatments to control competition. Analyses seek to determine the effect of these treatments on (i) the light conditions, (ii) the cover of competing vegetation, and (iii) the growth and vigor of planted trees. Results show that increasing shrub clearing intensity has reduced the cover of tall competing vegetation after 5 years. However, light conditions and the cover of low competing vegetation around planted trees no longer vary significantly among treatments after 5 years. Strip clearing (SC) improved the growth of white ash and total clearing improved the growth of black walnut, with respect to site considered. Herbicide use was beneficial for the majority of species. SC presents a useful alternative for hardwood plantations. However, low competing vegetation control remains an important factor for increasing planted tree productivity in these managed shrub communities.
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Adams-Schimminger, Miriam, Graham Fifield, Bruce Doran, and David Freudenberger. "Woodland Rehabilitation and Biodiversity Conservation in an Agricultural Landscape in South Eastern Australia." Case Studies in the Environment 1, no. 1 (2017): 1–14. http://dx.doi.org/10.1525/cse.2017.sc.399598.
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Southern Australia has a tree crisis. The iconic and ecologically essential eucalypt trees are dying out across vast swathes of farmland that were once grassy woodlands. A century of clearing and agricultural intensification, plus the failure of these trees to self-regenerate, has led to a massive loss of wildlife habitat, particularly tree hollows that only form in large and old Eucalyptus trees. Just as importantly, this decline in trees has exposed farmers to losses of agricultural productivity. There is now a lack of shelter for livestock. Rising salty ground water is degrading pastures as this ground water is no longer being controlled by the deep roots and respiration of eucalypts. We describe the research that shows how an innovative partnership between farmers, a non-government environmental organisation, and government funding is rehabilitating entire fields to a productive and wildlife-rich woodland full of thriving eucalypts.
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Bigger, M. "The effect of attack by Amblypelta cocophaga China (Hemiptera:Coreidae) on growth of Eucalyptus deglupta in the Solomon Islands." Bulletin of Entomological Research 75, no. 4 (December 1985): 595–608. http://dx.doi.org/10.1017/s0007485300015856.
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AbstractReduction in growth of saplings of Eucalyptus deglupta resulting from die-back caused by Amblypelta cocophaga China was studied in forestry plantations in the Solomon Islands. At a standard spacing of 10 × 3 m, a comparison was made of tree growth and incidence of A. cocophaga attack on saplings planted in strips 2 m wide cut through secondary forest, with those from which all inter-row vegetation was cut back prior to planting. Initially, a greater proportion of trees was infested on the cleared than the uncleared plots, but at the end of the first year, at which time the attack was at its peak, no differences could be detected. From the fifth to the thirteenth month after planting out, uninfested trees on the cleared plots increased in height at an average rate of 60 cm per month. For every week that at least one A. cocophaga was recorded on a tree, this rate was depressed by 1·3 cm. On the uncleared plots, the average rate of increase of uninfested trees was only 42 cm per month and this was reduced by 1·0 cm for every week that an insect was recorded. By the end of the first year, an estimated 37% (in cleared plots) and 41% (in uncleared plots) of the potential stand was rendered useless for future timber production due to A. cocophaga damage. In terms of total stem volume (not log production), about 1 m3/h out of a potential 3 m3/h was lost in the uncleared plots and 0·2 m3/h out of a potential 0·6 m3/h in the uncleared ones. Whilst clearing did not reduce the incidence of A. cocophaga attack, the advantage of clearing in terms of increased tree growth was considerable.
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Bukata, Andrew R., and T. Kurtis Kyser. "Response of the Nitrogen Isotopic Composition of Tree-Rings Following Tree-Clearing and Land-Use Change." Environmental Science & Technology 39, no. 20 (October 2005): 7777–83. http://dx.doi.org/10.1021/es050733p.
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Carrigan, Christine E., T. Olaf Johnson, and Malcolm H. Ray. "Tree Planting and Clearing Guidance with Consideration of Minimized Crash Risk." Transportation Research Record: Journal of the Transportation Research Board 2588, no. 1 (January 2016): 110–15. http://dx.doi.org/10.3141/2588-12.
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Delwaide, Ann, and Louise Filion. "Les coupes forestières dans les pessières à lichens: effets sur la croissance et la régénération des conifères (Whapmagoostui, Québec subarctique)." Canadian Journal of Botany 66, no. 6 (June 1, 1988): 1013–20. http://dx.doi.org/10.1139/b88-146.
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In the Whapmagoostui area (east of Hudson Bay), tree harvesting by Crée Indians in lichen woodlands affects the form and the growth of surviving trees and also the forest population dynamics. A study of the growth form of white spruce (Picea glauca (Moench) Voss.) and black spruce (Picea mariana (Mill.) B.S.P.) that have been pruned shows the efficiency of a total traumatic reiteration process. After several years, the annual radial growth was equivalent to that recorded before pruning. In clear-cutting areas (more than 75% of trees removed), the increase in the radial growth of spared trees was 400 to 700%. The main factors that govern the success of regeneration in cutting areas are the rather small extension of the openings (<0.005 km2), the low intensity of tree harvesting (<75% of trees over 90% of the surface), the physical conditions of the lichenous ground cover and the abundance of the lignified debris after clearing vegetation, and the climatic conditions in the subsequent years.
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Dimou, D., J. Drossopoulou, E. Moschos, C. Varveri, and F. Bem. "First Report of Citrus tristeza virus in Greece." Plant Disease 86, no. 3 (March 2002): 329. http://dx.doi.org/10.1094/pdis.2002.86.3.329b.
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Large-scale surveys of Citrus spp. for the presence of Citrus tristeza virus (CTV) by the Ministry of Agriculture in Greece began in 1995. Over 26,000 trees have been tested by enzyme-linked immunosorbent assay and immunoprinting (2). In summer 2000, the first CTV-infected sweet orange cv. Lane Late tree grafted on CTV-tolerant Carrizo citrange was found in Argolis County, Peloponnese. This tree belonged to a batch of CAC propagation material (20 trees) illegally introduced from Spain in 1994, which was subsequently traced and found to be infected (45%). A follow-up search of trees grafted with the above material was undertaken in the two concerned regions (Argolis and Chania-Crete), and more than 3,500 trees have been removed. Extensive surveys continue to identify and destroy new infections. Few cases (15 of 16,800) of natural transmission to cultivars other than cv. Lane Late have been found. All of these have been close to the initially infected trees in the Argolis area. Surveys in spring 2001 were extended to certified propagation material of Clemenpons mandarin on Carrizo citrange imported from Spain, and 7 of 1,038 plants were infected (0.64%). The virus was successfully graft-transmitted to sweet orange cv. Madame Vinous and sweet lime seedlings, where it was identified by immunoprinting and reverse transcription-polymerase chain reaction (1). Mild vein clearing symptoms appeared on both indicators. Vein clearing on sweet lime was also accompanied by leaf cupping. To our knowledge, this is the first report of CTV in Greece. References: (1) A. Sambade et al. J. Virol. Methods 87:25, 2000. (2) C. Vela et al. J. Gen. Virol. 67:91, 1986.
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Schmidt, Susanne, and Rebecca E. Lamblea. "Nutrient dynamics in Queensland savannas: implications for the sustainability of land clearing for pasture production." Rangeland Journal 24, no. 1 (2002): 96. http://dx.doi.org/10.1071/rj02005.
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Eucalyptus savannas on low nutrient soils are being extensively cleared in Queensland. In this paper we provide background information relevant to understanding nutrient (particularly nitrogen) dynamics in sub/tropical savanna, and review the available evidence relevant to understanding the potential impact of clearing Eucalyptus savanna on nutrient relations. The limited evidence presently available can be used to argue for the extreme positions that: (i) woody vegetation competes with grasses for resources, and tree/shrub clearing improves pasture production, (ii) woody vegetation benefits pasture production. At present, the lack of fundamental knowledge about Australian savanna nutrient relations makes accurate predictions about medium- and long-term effects of clearing on nutrient relations in low nutrient savannas difficult. The future of cleared savannas will differ if herbaceous species maintain all functions that woody vegetation has previously held, or if woody species have functions distinct from those of herbaceous vegetation. Research suggests that savanna soils are susceptible to nitrate leaching, and that trees improve the nutrient status of savanna soils in some situations. The nitrogen capital of cleared savanna is at risk if mobile ions are not captured efficiently by the vegetation, and nitrogen input via N2 fixation from vegetation and microbiotic crusts is reduced. In order to predict clearing effects on savanna nutrient relations, research should be directed to answering (i) how open or closed nutrient cycles are in natural and cleared savanna, (ii) which functions are performed by savanna constituents such as woody and herbaceous vegetation, native and exotic plant species, termites, and microbiotic crusts in relation to nutrient cycles. In the absence of detailed knowledge about savanna functioning, clearing carries the risk of promoting continuous nutrient depletion.
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Ouellet, D., and R. Zarnovican. "La conduite des jeunes peuplements de bouleaux jaunes (Betulaalleghaniensis Britton): caractéristiques morphologiques." Canadian Journal of Forest Research 19, no. 8 (August 1, 1989): 992–96. http://dx.doi.org/10.1139/x89-152.
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The morphological characteristics of a young yellow birch stand (Betulaalleghaniensis Britton) were studied according to class height and class development, according to the classification criteria set by IUFRO. The results show that the crown projection ratio, b/dhp, and the ratio h/dhp are strongly correlated to the social position and the vitality of the trees. During clearing, these two morphological ratios should be considered in distinguishing among primary, useful accessory, and harmful accessory trees. The differentiation of trees in social classes is emphasized by competition for growing space and will result in the modification of the dynamics of tree morphology and stem growth volume.
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Ellis, C. R., J. W. Pomeroy, T. Brown, and J. MacDonald. "Simulation of snow accumulation and melt in needleleaf forest environments." Hydrology and Earth System Sciences Discussions 7, no. 1 (February 9, 2010): 1033–72. http://dx.doi.org/10.5194/hessd-7-1033-2010.
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Abstract. Drawing upon numerous field studies and modelling exercises of snow processes, the Cold Regions Hydrological Model (CRHM) was developed to simulate the four season hydrological cycle in cold regions. CRHM includes modules describing radiative, turbulent and conductive energy exchanges to snow in forest and open environments, as well as provide account for losses from canopy snow sublimation and rain evaporation. Due to the physical-basis and rigorous testing of each module, there is a minimal need for model calibration. To evaluate CRHM, simulations of snow accumulation and melt were compared to observations collected at paired forest and clearing sites of varying latitude, elevation, forest cover density, and climate. Overall, results show that CRHM is capable of characterising the variation of snow accumulation between forest and open sites, achieving a model efficiency of 0.57, with the lowest efficiencies at the forest sites. Simulations of canopy sublimation losses slightly overestimated observed losses from a weighed cut tree, giving a model efficiency of 0.41 for daily losses. Good model performance was demonstrated in simulating energy fluxes to snow at the clearings, but performance was degraded from this under forest canopies due to errors in simulating daily net longwave radiation. However, expressed as cumulative energy to snow over the winter, simulated values were 96% and 98% of that observed at forest and clearing sites, respectively. Overall, good model prediction of the substantial variations in mass and energy between forest and clearing sites suggests that CRHM may be useful as an analytical or predictive tool for snow processes in needleleaf forests.
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Ludwig, J., and D. Tongway. "Clearing savannas for use as rangelands in Queensland: altered landscapes and water-erosion processes." Rangeland Journal 24, no. 1 (2002): 83. http://dx.doi.org/10.1071/rj02004.
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This paper presents a framework and some examples of how tree clearing alters landscapes (vegetation structure and faunal habitat) and processes (run-off and soil erosion) for eucalypt savannas in Queensland. Unaltered savannas have a tree-layer and a well-covered ground-layer of perennial grasses, and they provide habitats favoured by a variety of open woodland birds, reptiles and small mammals. Because unaltered savannas have a high ground-cover, they have low rates of run-off and erosion. When savannas are chained, but otherwise unaltered, trees rapidly regrow and increase in canopy cover. The exotic buffel grass often establishes in chained regrowth (especially if grazed), although the cover of native grasses such as black speargrass remains high (unless heavily grazed). We found that open woodland birds declined on these chained regrowth sites, except for the Weebill, which increased in abundance. When savannas are cleared of trees and woody debris and developed as improved pasture systems, both exotic and native perennial grass increased in cover. However, open woodland fauna abundance declined whereas grassland fauna such as the Red-backed Fairy-wren and the House Mouse increased in abundance. If these pasture sites are heavily utilised by livestock so that ground-cover is reduced, rates of run-off and soil loss are likely to rapidly increase, especially as cover declines below 40%. These run-off and erosion findings suggest that the manner in which savanna landscapes are cleared and subsequently used will have flow-on effects at catchment scales.
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CHIDUMAYO, EMMANUEL N. "Estimating tree biomass and changes in root biomass following clear-cutting of Brachystegia-Julbernardia (miombo) woodland in central Zambia." Environmental Conservation 41, no. 1 (June 18, 2013): 54–63. http://dx.doi.org/10.1017/s0376892913000210.
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SUMMARYThis study aimed at developing allometric models from destructive sample field data for estimating both aboveground and belowground tree biomass and assessing changes in root biomass after old-growth Brachystegia-Julbernardia (miombo) woodland clearing in central Zambia. Logarithmic linear models were selected for estimating tree biomass because they gave the most accurate (low mean error) predictions. On average aboveground and belowground biomass in regrowth woodland represented 29% and 41%, respectively, of the biomass in old-growth woodland. The root:shoot ratios were 0.54 and 0.77 in old-growth and regrowth woodland, respectively. Ten years after clear-cutting old-growth woodland, root biomass loss was about 60% of the original biomass. The main cause of post clearing root biomass loss was fire which at the study sites occurred annually or biannually. Control of fire in cleared sites should be encouraged in forest management for carbon storage and sequestration in miombo woodland of southern Africa.
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Mawson, P. R., and C. E. Cooper. "The effect of changing land use on the availability of potential nest trees for the endangered Muir's corella (Cacatua pastinator pastinator): a case study of the establishment of commercial Tasmanian blue gum plantations in Western Australia." Pacific Conservation Biology 21, no. 2 (2015): 146. http://dx.doi.org/10.1071/pc14913.
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In the mid-1990s commercial Tasmanian blue gum (Eucalyptus globulus) plantations were established in south-west Western Australia. We examined the extent of loss of potential nesting trees for an endangered obligate hollow-nesting cockatoo, Muir’s corella (Cacatua pastinator pastinator), resulting from establishment of these plantations during 1995–2004. Clearing of native vegetation was extensive in both Tonebridge (51%) and Frankland (76%) study sites. The proportion of land used for timber plantation increased significantly from 2.4% to 12.1% (Tonebridge) and 0.5% to 9% (Frankland) in the period 1995–2004. Plantations were predominantly established on already cleared farmland, but during the rapid development of plantations, large numbers of remnant paddock trees (mean = 56%) in cleared farmland were removed. Despite the loss of more than 50% of potential nesting habitat over an area of 376km2 within its current distribution, Muir’s corella continued to increase in numbers. However, there are concerns about delayed impacts of the clearing of potential nest trees we have observed, and consequences of further tree loss during future plantation harvesting. Evidence-based demonstration of biodiversity protection is increasingly needed to fulfil forest and plantation stewardship requirements, so greater care needs to be directed towards the management of extant remnant vegetation in paddocks.
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Cox, K. D., H. Scherm, and N. Serman. "Ground-penetrating Radar to Detect and Quantify Residual Root Fragments Following Peach Orchard Clearing." HortTechnology 15, no. 3 (January 2005): 600–607. http://dx.doi.org/10.21273/horttech.15.3.0600.
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Consecutive replanting of peach (Prunus persica) trees on the same orchard site can result in various replant problems and diseases, including armillaria root disease (Armillaria spp.), which develops upon contact between the roots of newly planted trees and infested residual root pieces in the soil. There is little information regarding the quantity of roots remaining in stone fruit orchards following tree removal and land clearing. We investigated the utility of ground-penetrating radar (GPR) to characterize reflector signals from peach root fragments in a controlled burial experiment and to quantify the amount of residual roots remaining after typical commercial orchard clearing. In the former experiment, roots ranging from 2.5 to 8.2 cm in diameter and buried at depths of 11 to 114 cm produced characteristic parabolic reflector signals in radar profiles. Image analysis of high-amplitude reflector area indicated significant linear relationships between signal strength (mean pixel intensity) and root diameter (r = -0.517; P = 0.0097; n = 24) or the combined effects of root diameter and burial depth, expressed though a depth × diameter term (r = -0.630; P = 0.0010; n = 24). In a peach orchard in which trees and roots had been removed following typical commercial practice (i.e., trees were pushed over, burned, and tree rows subsoiled), a GPR survey of six 4 × 8-m plots revealed that the majority of reflector signals indicative of root fragments were located in the upper 30 to 40 cm of soil. Based on ground-truth excavation of selected sites within plots, reflectors showing a strong parabolic curvature in the radar profiles corresponded to residual root fragments with 100% accuracy, whereas those displaying a high amplitude area represented roots in 86.1% of the cases. By contrast, reflectors with both poor curvature and low amplitude yielded roots for less than 10% of the excavated sites, whereas randomly selected sites lacking reflector signals were devoid of any roots or other subsurface objects. A high level of variability in the number of residual roots was inferred from the radar profiles of the six plots, indicating an aggregated distribution of root fragments throughout the field. The data further indicated that at least one residual root fragment would be present per cubic meter of soil, and that many of these fragments have diameters corresponding to good to excellent inoculum potential for armillaria root disease. Further GPR surveys involving different levels of land clearing, combined with long-term monitoring of armillaria root disease incidence in replanted trees, will be necessary to ascertain the disease threat posed by the levels of residual root biomass observed in this study.
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Caras, Tamir, and Carmi Korine. "Effect of vegetation density on the use of trails by bats in a secondary tropical rain forest." Journal of Tropical Ecology 25, no. 1 (January 2009): 97–101. http://dx.doi.org/10.1017/s0266467408005671.
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Natural forests are composed of a heterogeneous mixture of plant architectures that change temporally and spatially. In addition, variation in ridges, tree falls, natural clearing, logs and animal or man-made paths results in a topographic complexity which is likely to have a profound effect on the movements of animals within the forest.