Academic literature on the topic 'Conifer-broadleaf forest'
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Journal articles on the topic "Conifer-broadleaf forest"
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Tsukada, Matsuo. "Map of Vegetation during the Last Glacial Maximum in Japan." Quaternary Research 23, no. 3 (May 1985): 369–81. http://dx.doi.org/10.1016/0033-5894(85)90041-9.
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A vegetation map reconstructed for the Japanese Archipelago (based upon pollen data from 28 sites and plant macrofossil data from 33 sites) at the time of last glacial maximum shows that coniferous forests covered extensive areas of the land. Boreal conifer forests (dominated by thePicea jezoensiscomplex,P. glehnii, Abies sachalinensis, A. mariesii, Tsuga diversifolia, andPinuswithLarix gmelinii, though the latter species was confined only to the northern part of northeastern Honshu and Hokkaido) occupied the modern cool-temperature deciduous broadleaf and mid-temperate conifer forest zones, and temperate coniferous forests (mainlyPicea maximowiczii, P. polita, P. bicolor, P. koyamai, Abies firma, A. homolepis, Tsuga sieboldii, andPinus), the present warm-temperate evergreen (laurilignosa) forest zone. Small populations of various broadleaf forest species were scattered in the full-glacial temperate conifer forest mainly along the coastal belt, and the true laurilignosa forest was limited in distribution, occurring only in the paleo-Yaku Peninsula.
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Abele, Suzanne E., S. Ellen Macdonald, and John R. Spence. "Cover type, environmental characteristics, and conservation of terrestrial gastropod diversity in boreal mixedwood forests." Canadian Journal of Forest Research 44, no. 1 (January 2014): 36–44. http://dx.doi.org/10.1139/cjfr-2013-0210.
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Terrestrial gastropods are important decomposers, herbivores, and prey items in forest systems and constitute a poorly understood element of forest biodiversity in Canada. We sampled terrestrial gastropod assemblages in northwestern Alberta, Canada, using board traps and forest floor sampling to examine their association with forest composition, structure, and environment (forest floor depth and moisture, coarse woody debris, understory vegetation cover) in four boreal mixedwood cover types: broadleaf (deciduous) dominated (DDOM), broadleaf (deciduous) dominated with coniferous understory (DDOMU), mixed conifer and broadleaf (MX), and conifer dominated (CDOM). The highest total gastropod abundance and richness occurred in the DDOM cover type. Furthermore, DDOM assemblages accumulated species more quickly (with sampling effort) and supported more gastropod species at higher levels of dominance than found in other cover types. The mix of coniferous and broadleaved trees influenced gastropod distributions within stands; however, associations observed between gastropod species and tree species differed among cover types, suggesting complex ecological contingency. For example, conifer basal area was an important driver of gastropod assemblage in DDOM and DDOMU forests, whereas broadleaf basal area was the most important driver in the CDOM forest type. We conclude that tree species mixture at a variety of scales sustains diversity of gastropod assemblages and that this understanding is significant for conservation of this taxon on mixedwood boreal forest landscapes.
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Huesca, Margarita, Keely L. Roth, Mariano García, and Susan L. Ustin. "Discrimination of Canopy Structural Types in the Sierra Nevada Mountains in Central California." Remote Sensing 11, no. 9 (May 8, 2019): 1100. http://dx.doi.org/10.3390/rs11091100.
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Accurate information about ecosystem structure and biogeochemical properties is essential to providing better estimates ecosystem functioning. Airborne LiDAR (light detection and ranging) is the most accurate way to retrieve canopy structure. However, accurately obtaining both biogeochemical traits and structure parameters requires concurrent measurements from imaging spectrometers and LiDARs. Our main objective was to evaluate the use of imaging spectroscopy (IS) to provide vegetation structural information. We developed models to estimate structural variables (i.e., biomass, height, vegetation heterogeneity and clumping) using IS data with a random forests model from three forest ecosystems (i.e., an oak-pine low elevation savanna, a mixed conifer/broadleaf mid-elevation forest, and a high-elevation montane conifer forest) in the Sierra Nevada Mountains, California. We developed and tested general models to estimate the four structural variables with accuracies greater than 75%, for the structurally and ecologically different forest sites, demonstrating their applicability to a diverse range of forest ecosystems. The model R2 for each structural variable was least in the conifer/broadleaf forest than either the low elevation savanna or the montane conifer forest. We then used the structural variables we derived to discriminate site-specific, ecologically meaningful descriptions of canopy structural types (CST). Our CST results demonstrate how IS data can be used to create comprehensive and easily interpretable maps of forest structural types that capture their major structural features and trends across different vegetation types in the Sierra Nevada Mountains. The mixed conifer/broadleaf forest and montane conifer forest had the most complex structures, containing six and five CSTs respectively. The identification of CSTs within a site allowed us to better identify the main drivers of structural variability in each ecosystem. CSTs in open savanna were driven mainly by differences in vegetation cover; in the mid-elevation mixed forest, by the combination of biomass and canopy height; and in the montane conifer forest, by vegetation heterogeneity and clumping.
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Hastings, Jack H., Scott V. Ollinger, Andrew P. Ouimette, Rebecca Sanders-DeMott, Michael W. Palace, Mark J. Ducey, Franklin B. Sullivan, David Basler, and David A. Orwig. "Tree Species Traits Determine the Success of LiDAR-Based Crown Mapping in a Mixed Temperate Forest." Remote Sensing 12, no. 2 (January 17, 2020): 309. http://dx.doi.org/10.3390/rs12020309.
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The ability to automatically delineate individual tree crowns using remote sensing data opens the possibility to collect detailed tree information over large geographic regions. While individual tree crown delineation (ITCD) methods have proven successful in conifer-dominated forests using Light Detection and Ranging (LiDAR) data, it remains unclear how well these methods can be applied in deciduous broadleaf-dominated forests. We applied five automated LiDAR-based ITCD methods across fifteen plots ranging from conifer- to broadleaf-dominated forest stands at Harvard Forest in Petersham, MA, USA, and assessed accuracy against manual delineation of crowns from unmanned aerial vehicle (UAV) imagery. We then identified tree- and plot-level factors influencing the success of automated delineation techniques. There was relatively little difference in accuracy between automated crown delineation methods (51–59% aggregated plot accuracy) and, despite parameter tuning, none of the methods produced high accuracy across all plots (27—90% range in plot-level accuracy). The accuracy of all methods was significantly higher with increased plot conifer fraction, and individual conifer trees were identified with higher accuracy (mean 64%) than broadleaf trees (42%) across methods. Further, while tree-level factors (e.g., diameter at breast height, height and crown area) strongly influenced the success of crown delineations, the influence of plot-level factors varied. The most important plot-level factor was species evenness, a metric of relative species abundance that is related to both conifer fraction and the degree to which trees can fill canopy space. As species evenness decreased (e.g., high conifer fraction and less efficient filling of canopy space), the probability of successful delineation increased. Overall, our work suggests that the tested LiDAR-based ITCD methods perform equally well in a mixed temperate forest, but that delineation success is driven by forest characteristics like functional group, tree size, diversity, and crown architecture. While LiDAR-based ITCD methods are well suited for stands with distinct canopy structure, we suggest that future work explore the integration of phenology and spectral characteristics with existing LiDAR as an approach to improve crown delineation in broadleaf-dominated stands.
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Milios, Elias, Kyriaki Kitikidou, and Kalliopi Radoglou. "New Silvicultural Treatments for Conifer Peri-Urban Forests Having Broadleaves in the Understory - The First Application in the Peri-Urban of Xanthi in Northeastern Greece." South-east European forestry 10, no. 2 (October 31, 2019): 107–16. http://dx.doi.org/10.15177/seefor.19-16.
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Background and Purpose: In Greece, forest practice did not develop special silvicultural treatments for planted conifer peri-urban forests where broadleaf trees appear as natural regeneration in the understory. The aims of this study are: a) to analyze the new proposed selective silvicultural treatments for the planted peri-urban forest of Xanthi and for analogous planted conifer forests, where broadleaf trees are naturally established in the understory b) to check the research hypothesis that the new selective silvicultural treatments exhibited higher intensity in terms of the basal area of cut trees, compared to that of traditional treatments in the studied peri-urban forest. Materials and Methods: In the traditional treatments, in the pine overstory cuttings, apart from the dead trees, mainly the malformed, damaged, suppressed and intermediate trees were cut. In the lower stories, the goal of the thinning was the more or less uniform distribution of broadleaf trees. In the proposed selective treatments, the main aim of pine cuttings is to release the broadleaf formations growing in the lower stories, while the treatments of the broadleaf trees will be a form of “positive selection” thinning. Plots were established in areas where the two types of treatments were going to be applied. In each plot, tree measurements and a classification of living trees into crown classes took place. After the application of the treatments the characteristics of cut trees were recorded. Results: In the established plots, before the cuttings (and thinning), total basal area was not statistically significantly different between the two types of treatments. In selective treatments, the basal area of all cut trees was statistically significantly higher than that of the results of traditional treatments. In the broadleaf cut trees there were statistical differences in the ratios of dominant, intermediate and suppressed trees between the two silvicultural approaches. Conclusions: The research hypothesis was verified. The intensity of treatments in terms of the basal area of cut trees was higher in the selective approach, compared to the traditional treatments in the Xanthi peri-urban forest. However, the overstory cutting intensity of the selective treatments depends on the spatial distributions and densities of broadleaved and conifer trees. In the broadleaf trees, the different objectives of the two types of treatments resulted in thinning with different qualitative characteristics. The proposed silvicultural treatments will accelerate the conversion of peri-urban conifer forests having an understory of broadleaf trees into broadleaved forests, or into mixed forests of conifers and broadleaf trees.
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Hawkins, C. D. B., A. Dhar, and B. J. Rogers. "How much birch (Betula papyrifera) is too much for maximizing spruce (Picea glauca) growth: a case study in boreal spruce plantation forests." Journal of Forest Science 58, No. 7 (July 27, 2012): 314–27. http://dx.doi.org/10.17221/8/2012-jfs.
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Interest in conifer-broadleaf mixedwood forests has greatly increased due to continuous demand for hardwood products and a shift towards more biological or ecosystem-based management. In British Columbia, more than 30% of the productive forest land is a conifer–broadleaf mixture and current forest regulations are more conifer biased rather than maintaining a mixed-species condition. The aim of this study was to examine the impact of paper birch on white spruce growth. Spruce growth data from 10 to 18 years old complex stands indicate that radial, height, and stem volume was not impacted by retaining up to 3,000 stems·ha<sup>–1</sup> of birch. Similarly, growth and yield model projections suggest spruce-birch stands would be more productive up to a threshold birch density (3,000 stems·ha<sup>–1</sup>) than pure spruce stands. At a 4% real interest rate, the removal of birch from these stands does not appear to be warranted as an investment. The results suggest that instead of encouraging uniform broadleaf removal across conifer plantations, mixed species management strategies could enhance the forest productivity, stand diversity and resilience.
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Bjerreskov, Kristian Skau, Thomas Nord-Larsen, and Rasmus Fensholt. "Classification of Nemoral Forests with Fusion of Multi-Temporal Sentinel-1 and 2 Data." Remote Sensing 13, no. 5 (March 3, 2021): 950. http://dx.doi.org/10.3390/rs13050950.
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Mapping forest extent and forest cover classification are important for the assessment of forest resources in socio-economic as well as ecological terms. Novel developments in the availability of remotely sensed data, computational resources, and advances in areas of statistical learning have enabled the fusion of multi-sensor data, often yielding superior classification results. Most former studies of nemoral forests fusing multi-sensor and multi-temporal data have been limited in spatial extent and typically to a simple classification of landscapes into major land cover classes. We hypothesize that multi-temporal, multi-sensor data will have a specific strength in the further classification of nemoral forest landscapes owing to the distinct seasonal patterns in the phenology of broadleaves. This study aimed to classify the Danish landscape into forest/non-forest and further into forest types (broadleaved/coniferous) and species groups, using a cloud-based approach based on multi-temporal Sentinel 1 and 2 data and a random forest classifier trained with National Forest Inventory (NFI) data. Mapping of non-forest and forest resulted in producer accuracies of 99% and 90%, respectively. The mapping of forest types (broadleaf and conifer) within the forested area resulted in producer accuracies of 95% for conifer and 96% for broadleaf forest. Tree species groups were classified with producer accuracies ranging 34–74%. Species groups with coniferous species were the least confused, whereas the broadleaf groups, especially Quercus species, had higher error rates. The results are applied in Danish national accounting of greenhouse gas emissions from forests, resource assessment, and assessment of forest biodiversity potentials.
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Brassard, Brian W., Han Y. H. Chen, Jian R. Wang, and Peter N. Duinker. "Effects of time since stand-replacing fire and overstory composition on live-tree structural diversity in the boreal forest of central Canada." Canadian Journal of Forest Research 38, no. 1 (January 2008): 52–62. http://dx.doi.org/10.1139/x07-125.
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Stand structure diversity is hypothesized (i) to increase with stand development and (ii) to be greater in mixedwood stands than in conifer and broadleaf stands. We examined the effects of time since stand-replacing fire (TSF) and overstory type on stand volume, stand density, and tree-size variability, which is measured using Shannon’s diversity index (H′) and coefficient of variation, in fire-origin boreal forest stands. We sampled 36 stands representing conifer, mixedwood, and broadleaf overstory types, ranging in ages from 72 to 201 years TSF on upland mesic sites in northwestern Ontario, Canada. Stand volume decreased in older mixedwood and broadleaf stands, but followed a U-shaped pattern in conifer stands with TSF. Diameter-at-breast-height-based H′ followed an inverse U-shaped pattern with TSF for all overstory types. Height-based H′ decreased with TSF in conifer and mixedwood stands but peaked at the intermediate age class in broadleaf stands. Diameter-at-breast-height- and height-based coefficient of variation indices followed an inverse U-shaped distribution with TSF. Our results partially supported the two hypotheses, as (i) the 124- to 139-year-old stands were most diverse and (ii) mixedwood stands were more than or as equally diverse as conifer and broadleaf stands, depending on stand development stage and the diversity indices used.
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Schumacher, Johannes, Margret Rattay, Melanie Kirchhöfer, Petra Adler, and Gerald Kändler. "Combination of Multi-Temporal Sentinel 2 Images and Aerial Image Based Canopy Height Models for Timber Volume Modelling." Forests 10, no. 9 (August 30, 2019): 746. http://dx.doi.org/10.3390/f10090746.
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Multi-temporal Sentinel 2 optical images and 3D photogrammetric point clouds can be combined to enhance the accuracy of timber volume models on large spatial scale. Information on the proportion of broadleaf and conifer trees improves timber volume models obtained from 3D photogrammetric point clouds. However, the broadleaf-conifer information cannot be obtained from photogrammetric point clouds alone. Furthermore, spectral information of aerial images is too inconsistent to be used for automatic broadleaf-conifer classification over larger areas. In this study we combined multi-temporal Sentinel 2 optical satellite images, 3D photogrammetric point clouds from digital aerial stereo photographs, and forest inventory plots representing an area of 35,751 km2 in south-west Germany for (1) modelling the percentage of broadleaf tree volume (BL%) using Sentinel 2 time series and (2) modelling timber volume per hectare using 3D photogrammetric point clouds. Forest inventory plots were surveyed in the same years and regions as stereo photographs were acquired (2013–2017), resulting in 11,554 plots. Sentinel 2 images from 2016 and 2017 were corrected for topographic and atmospheric influences and combined with the same forest inventory plots. Spectral variables from corrected multi-temporal Sentinel 2 images were calculated, and Support Vector Machine (SVM) regressions were fitted for each Sentinel 2 scene estimating the BL% for corresponding inventory plots. Variables from the photogrammetric point clouds were calculated for each inventory plot and a non-linear regression model predicting timber volume per hectare was fitted. Each SVM regression and the timber volume model were evaluated using ten-fold cross-validation (CV). The SVM regression models estimating the BL% per Sentinel 2 scene achieved overall accuracies of 68%–75% and a Root Mean Squared Error (RMSE) of 21.5–26.1. The timber volume model showed a RMSE% of 31.7%, a mean bias of 0.2%, and a pseudo-R2 of 0.64. Application of the SVM regressions on Sentinel 2 scenes covering the state of Baden-Württemberg resulted in predictions of broadleaf tree percentages for the entire state. These predicted values were used as additional predictor in the timber volume model, allowing for predictions of timber volume for the same area. Spatially high-resolution information about growing stock is of great practical relevance for forest management planning, especially when the timber volume of a smaller unit is of interest, for example of a forest stand or a forest district where not enough terrestrial inventory plots are available to make reliable estimations. Here, predictions from remote-sensing based models can be used. Furthermore, information about broadleaf and conifer trees improves timber volume models and reduces model errors and, thereby, prediction uncertainties.
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Jayathunga, Sadeepa, Toshiaki Owari, and Satoshi Tsuyuki. "Digital Aerial Photogrammetry for Uneven-Aged Forest Management: Assessing the Potential to Reconstruct Canopy Structure and Estimate Living Biomass." Remote Sensing 11, no. 3 (February 8, 2019): 338. http://dx.doi.org/10.3390/rs11030338.
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Scientifically robust yet economical and efficient methods are required to gather information about larger areas of uneven-aged forest resources, particularly at the landscape level, to reduce deforestation and forest degradation and to support the sustainable management of forest resources. In this study, we examined the potential of digital aerial photogrammetry (DAP) for assessing uneven-aged forest resources. Specifically, we tested the performance of biomass estimation by varying the conditions of several factors, e.g., image downscaling, vegetation metric extraction (point cloud- and canopy height model (CHM)-derived), modeling method ((simple linear regression (SLR), multiple linear regression (MLR), and random forest (RF)), and season (leaf-on and leaf-off). We built dense point clouds and CHMs using high-resolution aerial imagery collected in leaf-on and leaf-off conditions of an uneven-aged mixed conifer–broadleaf forest. DAP-derived vegetation metrics were then used to predict the dominant height and living biomass (total, conifer, and broadleaf) at the plot level. Our results demonstrated that image downscaling had a negative impact on the accuracy of the dominant height and biomass estimation in leaf-on conditions. In comparison to CHM-derived vegetation metrics, point cloud-derived metrics performed better in dominant height and biomass (total and conifer) estimations. Although the SLR (%RMSE = 21.1) and MLR (%RMSE = 18.1) modeling methods produced acceptable results for total biomass estimations, RF modeling significantly improved the plot-level total biomass estimation accuracy (%RMSE of 12.0 for leaf-on data). Overall, leaf-on DAP performed better in total biomass estimation compared to leaf-off DAP (%RMSE of 15.0 using RF modeling). Nevertheless, conifer biomass estimation accuracy improved when leaf-off data were used (from a %RMSE of 32.1 leaf-on to 23.8 leaf-off using RF modeling). Leaf-off DAP had a negative impact on the broadleaf biomass estimation (%RMSE > 35% for SLR, MLR, and RF modeling). Our results demonstrated that the performance of forest biomass estimation for uneven-aged forests varied with statistical representations as well as data sources. Thus, it would be appropriate to explore different statistical approaches (e.g., parametric and nonparametric) and data sources (e.g., different image resolutions, vegetation metrics, and leaf-on and leaf-off data) to inform the interpretation of remotely sensed data for biomass estimation for uneven-aged forest resources.
Dissertations / Theses on the topic "Conifer-broadleaf forest"
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Berry, Christopher J. J. "Post-dispersal seed predation in a conifer-broadleaf forest remnant : the importance of exotic mammals." Lincoln University, 2006. http://hdl.handle.net/10182/666.
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Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.
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Toïgo, Maude. "Productivité des forêts mélangées : effet de la diversité en essences dans un contexte climatique et édaphique variable." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2018.
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Les changements environnementaux à l’échelle globale peuvent se traduire par une modification des conditions abiotiques et de la diversité biologique. La fonction de production des écosystèmes forestiers a la particularité d'être à la fois soumise à, et régulatrice de ces changements environnementaux. Il apparaît alors primordial de comprendre la manière dont la diversité en essences et les facteurs abiotiques exercent le contrôle de cette fonction. Au cours de mes travaux j’ai étudié la variation de l'effet du mélange d’essences sur leur productivité dans un contexte climatique et édaphique changeant. Grâce à une double approche, basée sur des données locales et des données de l'Inventaire forestier national, je me suis concentrée sur cinq espèces forestières européennes majeures en peuplements purs et bispécifiques : Quercus petraea, Pinus sylvestris, Fagus sylvatica, Abies alba et Picea abies. En plaine je montre que l'effet du mélange d’essences varie peu avec les facteurs abiotiques. De plus cet effet est déterminé par la tolérance à l'ombrage de l'espèce accompagnatrice. En montagne l’effet du mélange d’essences sur leur productivité est plus fort et positif lorsque les facteurs abiotiques sont les plus limitants pour la croissance. Ces résultats illustrent l’intérêt d'intégrer les facteurs abiotiques et les caractéristiques fonctionnelles des espèces comme déterminants de l'effet de la diversité biologique sur les fonctions de l'écosystèmeGlobal environmental changes may lead to a modification of abiotic factors and biological diversity. The production function in forest ecosystems has the particularity to be both subjected to, and a regulator of, these environmental changes. Understanding how forest productivity is driven by species diversity and environmental factors is therefore a critical issue. This PhD thesis studies how tree species mixture affects their productivity along edaphic and climatic gradients. Based on an approach using both an original dataset and the national forest inventory dataset, I focused on five major species of European forests in pure and two-species forests: Quercus petraea, Pinus sylvestris, Fagus sylvatica, Abies alba and Picea abies. In lowlands, abiotic factors had little impacts on the outcome of tree species mixture on productivity. In addition, the effect of tree species mixture was determined by the shade tolerance of companion species. In highlands, the positive effects of tree species mixture were strongest when the abiotic factors were the most limiting for growth. These results highlight the importance of considering abiotic factors and the functional characteristics of species as drivers of the effect of biological diversity on ecosystem functions
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Li, Qin Guo, and 李欽國. "A comparison of bird communities between conifer plantation and natural broadleaf forest." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/27870428396496272912.
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Hsiao, Hung-Min, and 蕭泓泯. "A comparative study of nutrient input-output at natural broadleaf forest and conifer plantation at Lien-hua-chi Experimental Forest." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/49384854232525309811.
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碩士國立彰化師範大學
地理學系
94
Precipitation and stream water (including natural hardwood and conifer plantation watersheds) in Lien-hua-chi Experimental Forest were collected in 2005 to examine its chemical composition and evaluate nutrient input and output in a natural hardwood forest and a conifer plantation. Results indicate that the volume-weighted mean annual pH of wet-only precipitation was 4.84, lower than the criterion for acid rain (pH < 5.0). It was also lower than the value measured a decade ago at the same site (5.51), despite decreases in the emission of acidic pollutants over the same period of time. Coincident decreases in the emission of particulate pollutants with high concentrations of acid-neutralizing base cations, as well as differences in the collection methods (wet-only versus bulk precipitation) were possible explanations for the observed difference in precipitation pH. Seasonally, the lower pH occurred in spring (4.79) and winter (4.58) while summer (4.93) and fall (5.25) had higher pH. This pattern is in agreement with many other studies throughout Taiwan and is often attributed to the high contribution of pollutants transported from mainland China in the winter and spring. The deposition of all ions was much higher in spring and summer than in fall and winter. For acidic pollutants (sulfate and nitrate) the deposition in the spring and summer accounted for approximately 80% of the annual deposition. This asymmetry is attributable to the much higher quantity of precipitation in the summer and spring which comprised more than 80% of the annual rainfall. Volum-weighted annual mean concentration of Na+ (12.5 �惷q/L) and Cl- (7.9 �惷q/L) in precipitation at Lien-hua-chi Experimental Forest is lower than that in Taichung City (14.1 �惷q/L and 16.9 �惷q/L, respectively) which in turn is lower than that in Changhua City (23.3 �惷q/L and 29.1 �惷q/L, respectively) indicating a trend of decreasing oceanic influences with increasing distance from the coast. The rates of S and inorganic N deposition, approximately 11 kg/ha/yr, were higher than in northeastern America where high acid deposition is a major concern in forest nutrient cycling and health. The impact of such high acidic deposition on forest ecosystems of Taiwan needs to be examined thoroughly. The rate of S deposition observed in Lien-hua-chi Experimental Forest is similar to several other forest ecosystems in central Taiwan whereas the rate of N deposition at Lien-hua-chi Experimental Forest is considerably higher. It appears that high N deposition is more localized than S deposition. The application of commercial fertilizers around Lien-hua-chi Experimental Forest is likely the key to the observed higher N deposition at our study site compared to other forest ecosystems in central Taiwan. Four types of hydrological controls were used to describe how concentrations of different elements changed as a function of increased stream water discharge. The first type includes conductivity, Na+, Ca2+, Mg2+, SO42- and HCO3-, and can be described as dilution. Their concentrations decreased with increased stream water discharge possibly due to decreased relative contributions by baseflow source. Nitrate belongs to a second type that can be described as enhanced hydrological access possibly because it is mainly derived form the leaching associated with near surface water. Chloride can be described as the third form known as hydrologically constant because its concentration remain relatively unchanged throughout the entire water year. Finally a fourth type includes NH4+、K+、and H+. Elements in this group have no distinct relationship with discharge. Twenty-four years after clear-cutting, NH4+ and NO3- were the only two elements showing net gain state in the conifer plantation, especially in growing season (spring and summer) which contributed about 80 % of annual net gain. Possibly the 23 years old conifer plantation still needs considerable amount of inorganic N resulting in itse retention. Twenty-three years after the cutting the annual loss of base cations, Na, Ca2+ and Mg2+, in the conifer plantation were 1.4 ~ 1.8 times higher than in the natural hardwood forest.
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Yang, Kuo-Hsiang, and 楊國祥. "Effects of Thinning on the Soil Solution Chemistry in the Temperate Conifer-Broadleaf Mixed Forest in Taiping Mountain Area." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/09391404557236781737.
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碩士國立宜蘭大學
自然資源學系碩士班
95
Abstract In order to recognize the effect of forest thinning on the nutrient contents in soil solution and evaluating the benefit of forest thinning, eight thinning treatments were examined in this study, including control (0%, 3 plots) and thinning intensity of 25%, 28％, 30％, 33％, 37％, 38％ and 53％ (one plot for each treatment). The study area was located at the 61 forest compartment of Hoping Working Circle in Taipingshan area. Throughfall and rain water were collected monthly for measuring pH and nutrient content. Three soil samples for each experimental plot were also collected monthly by soil auger, including 0-10 cm, 10-20 cm and 20-30cm. Soil solution was extracted and prepared for measuring anions (Cl, NO3, SO4, PO4) and cations (NH4, K, Na, Ca, Mg, Fe, Al, Mn, Si). The objectives of this study were to (1) examine the variation of nutrient input under different thinning treatments by monitoring the changes of rain water and throughfall in one-year shortened and intensive monitoring period, and (2) to investigate the variation of nutrients in soil solution and discuss the benefit of forest thinning for propose the consultation to the forestry management in the future. The results of this study indicated that the pH value of rain water was lower than throughfall, which was attributed to the effect of acid deposition from atmosphere. The chemical compositions of soil solution suggested that the cation concentration decreased with the soil depth increased. We examined that the gradually decreased of cation with soil depth was due to the increasing effect of bio-factor (for example, nutrient absorption by roots and microbial fixation, etc.). The effect of forest thinning on the variation of soil solution chemical composition was changed with different thinning intensity. From the results of this study, we concluded that the operations of forest thinning could alter the soil nutrients content, and the changes were beneficial to the growth of remaining trees. Furthermore, in order to understand the chronic variation of forest thinning, the long-term monitoring was suggested to find out the periodic changes of forest thinning influence on the variation of forest soil moisture and nutrients content. Key words: Thinning, soil solution chemistry, soil nutrients, cations, anions
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Wen, Hsu Chia, and 許佳雯. "Effects of Thinning on the Dynamic of Litterfall Decomposition in the Temperate Conifer-Broadleaf Mixed Forest in Taiping Mountain Area, Taiwan." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/09691767756836067123.
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碩士國立宜蘭大學
自然資源學系碩士班
95
The 51-yr-old Japanese cedar (Cryptomeria japonica (L. f.) D. Don) plantation forest in Taiping mountain area was selected as the monitoring site for forest thinning experiment. The objective of this study was to investigate the impact of different thinning treatment (including control (0%), 25%, 28%, 30%, 33%, 37%, 38%, and 53% thinning treatment) on litter decomposition and soil nutrient release. After one year monitoring and analysis, the results showed that the litter mass decomposition constant was about 0.71-1.03 yr-1 during the study, and the order of decomposition intensity was heavy > light > medium thinning. The trends of C and Ca remaining mass (%) of the litter in litterbags were medium > light > heavy thinning. On the other hand, the trend of P remaining mass (%) was heavy > light > medium thinning. The trend of Mg was medium > heavy > light thinning. The trends of N was highest in light thinning region and K and Mg was highest in heavy thinning region, but have no consistent change between other thinning regions. Soil available N contents at 0-5 cm and 5-15 cm soil layers in heavy thinning are the highest, and suggested that the available N content after thinning was higher than that before thinning. The tendency of soil available K content in control region was higher than thinning treated regions at 0-5 cm soil depth. After thinning, the soil available P content was showed lower than control region at 0-5 cm depth, and has the tendency as heavy > light > medium thinning at 5-15 cm soil layer. The results of soil solution chemistry showed that the content of NH4, K, Na, and Si were higher than other cations, and the order of anions was SO4 > Cl > NO3. The tendency, including the total amounts of cations and anions, acid neutralizing capacity (ANC) and charge balance (CB) of soil solution, was showed that the control region was higher than thinning treated regions at both 0-5 cm and 5-15 cm soil layers. We examined that much more rain water were allowed for directly falling into soil surface after the canopy opening by forest thinning, and were resulted in strongly soil (or surface soil) leaching and reduced the nutrient elements content of soil solution in the thinning treated region. Besides, the study of litterfall decomposition was only one-year short term monitoring period, and we can not estimated the C and N fluxes under different forest thinning treatment from the results of the first year. For the consultation of evaluating the benefit of forest thinning management in Taiwan, it needs further researches for continually monitoring decomposition effects and estimating the C and N fluxes under different forest thinning treatment.
Books on the topic "Conifer-broadleaf forest"
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Comeau, P. G. LITE: A model for estimating light under broadleaf and conifer tree canopies. Victoria, BC: British Columbia Ministry of Forests Research Program, 1998.
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Silviculture of temperate and boreal broadleaf-conifer mixtures. Victoria, BC: Province of British Columbia, Ministry of Forests Research Program, 1996.
Find full textBook chapters on the topic "Conifer-broadleaf forest"
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Robakowski, Piotr, Tomasz P. Wyka, Wojciech Kowalkowski, Władysław Barzdajn, Emilia Pers-Kamczyc, Artur Jankowski, and Barbara Politycka. "Practical Implications of Different Phenotypic and Molecular Responses of Evergreen Conifer and Broadleaf Deciduous Forest Tree Species to Regulated Water Deficit in a Container Nursery." In Prime Archives in Environmental Research. Vide Leaf, Hyderabad, 2021. http://dx.doi.org/10.37247/paag.1.2020.5.
Full textConference papers on the topic "Conifer-broadleaf forest"
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Brown, L. J., C. M. Trotter, and M. R. Johnston. "Assessing the potential of sub-pixel classification in a mixed conifer-broadleaf forest." In IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings. (Cat. No.98CH36174). IEEE, 1998. http://dx.doi.org/10.1109/igarss.1998.699580.
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