Journal articles on the topic 'Conifer-broadleaf forest'
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1
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.
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Yang, Qiuli, Yanjun Su, Shichao Jin, Maggi Kelly, Tianyu Hu, Qin Ma, Yumei Li, et al. "The Influence of Vegetation Characteristics on Individual Tree Segmentation Methods with Airborne LiDAR Data." Remote Sensing 11, no. 23 (December 3, 2019): 2880. http://dx.doi.org/10.3390/rs11232880.
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This study investigated the effects of forest type, leaf area index (LAI), canopy cover (CC), tree density (TD), and the coefficient of variation of tree height (CVTH) on the accuracy of different individual tree segmentation methods (i.e., canopy height model, pit-free canopy height model (PFCHM), point cloud, and layer stacking seed point) with LiDAR data. A total of 120 sites in the Sierra Nevada Forest (California) and Shavers Creek Watershed (Pennsylvania) of the United States, covering various vegetation types and characteristics, were used to analyze the performance of the four selected individual tree segmentation algorithms. The results showed that the PFCHM performed best in all forest types, especially in conifer forests. The main forest characteristics influencing segmentation methods were LAI and CC, LAI and TD, and CVTH in conifer, broadleaf, and mixed forests, respectively. Most of the vegetation characteristics (i.e., LAI, CC, and TD) negatively correlated with all segmentation methods, while the effect of CVTH varied with forest type. These results can help guide the selection of individual tree segmentation method given the influence of vegetation characteristics.
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Clyne, Ailís B., Natalie L. Cleavitt, and Timothy J. Fahey. "Terrestrial Gastropod Grazing on Macrolichens in a Northern Broadleaf–Conifer Forest." Northeastern Naturalist 26, no. 2 (April 26, 2019): 261. http://dx.doi.org/10.1656/045.026.0203.
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Nagel, Thomas A., Jurij Diaci, Klemen Jerina, Milan Kobal, and Dusan Rozenbergar. "Simultaneous influence of canopy decline and deer herbivory on regeneration in a conifer–broadleaf forest." Canadian Journal of Forest Research 45, no. 3 (March 2015): 266–75. http://dx.doi.org/10.1139/cjfr-2014-0249.
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Understanding how forests respond to multiple disturbances is becoming increasingly important under global change. We examined the simultaneous influence of canopy decline and deer browsing on regeneration in an old-growth reserve and surrounding managed forest dominated by Fagus sylvatica L. and Abies alba Mill. in Slovenia. We quantified both disturbance processes by measuring characteristics of canopy gaps and reconstructing historical deer densities. Forest response was assessed with repeated measurements of tree regeneration and regeneration patterns within deer exclosures. Most gaps were formed by mortality of A. alba (71%), and gapmaker characteristics suggest that gaps formed slowly and often expanded, resulting in a mosaic of openings covering 17% of the old-growth reserve. Fagus sylvatica dominated the regeneration layer throughout the reserve and recruited to taller height classes over the past 26 years. The recruitment failure of preferred browse species (A. alba and Acer pseudoplatanus L.) in the reserve and the successful recruitment of these species within exclosures indicate that selective browsing by deer has altered the successional response to A. alba decline, facilitating the dominance of F. sylvatica. Given that global change may increase forest decline worldwide and the ubiquitous nature of deer browsing in many temperate forests, understanding their combined effects on forests will become increasingly important.
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Varin, Mathieu, Bilel Chalghaf, and Gilles Joanisse. "Object-Based Approach Using Very High Spatial Resolution 16-Band WorldView-3 and LiDAR Data for Tree Species Classification in a Broadleaf Forest in Quebec, Canada." Remote Sensing 12, no. 18 (September 21, 2020): 3092. http://dx.doi.org/10.3390/rs12183092.
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Species identification in Quebec, Canada, is usually performed with photo-interpretation at the stand level, and often results in a lack of precision which affects forest management. Very high spatial resolution imagery, such as WorldView-3 and Light Detection and Ranging have the potential to overcome this issue. The main objective of this study is to map 11 tree species at the tree level using an object-based approach. For modeling, 240 variables were derived from WorldView-3 with pixel-based and arithmetic feature calculation techniques. A global approach (11 species) was compared to a hierarchical approach at two levels: (1) tree type (broadleaf/conifer) and (2) individual broadleaf (five) and conifer (six) species. Five different model techniques were compared: support vector machine, classification and regression tree, random forest (RF), k-nearest neighbors, and linear discriminant analysis. Each model was assessed using 16-band or first 8-band derived variables, with the results indicating higher precision for the RF technique. Higher accuracies were found using 16-band instead of 8-band derived variables for the global approach (overall accuracy (OA): 75% vs. 71%, Kappa index of agreement (KIA): 0.72 vs. 0.67) and tree type level (OA: 99% vs. 97%, KIA: 0.97 vs. 0.95). For broadleaf individual species, higher accuracy was found using first 8-band derived variables (OA: 70% vs. 68%, KIA: 0.63 vs. 0.60). No distinction was found for individual conifer species (OA: 94%, KIA: 0.93). This paper demonstrates that a hierarchical classification approach gives better results for conifer species and that using an 8-band WorldView-3 instead of a 16-band is sufficient.
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Belyaeva, N. G., and T. V. Chernen’kova. "Relationship between Habitat Properties and Composition of Communities in Conifer–Broadleaf Forest." Russian Journal of Ecology 49, no. 2 (March 2018): 111–18. http://dx.doi.org/10.1134/s1067413618020042.
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Shiryaeva, O. S., and M. A. Palamarchuk. "New data on agaricoid fungi (Basidiomycota) of the Urals." Novosti sistematiki nizshikh rastenii 53, no. 1 (2019): 89–106. http://dx.doi.org/10.31111/nsnr/2019.53.1.89.
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Thirty six species of agaricoid fungi are reported for the first time for the Urals including 15 species new for the Komi Republic and 19 species new for the Sverdlovsk Region. They were found mostly in natural habitats: mountain tundra (3 species), mountain forest-tundra (3), the northern boreal forests of the mountains and their foothill (12), the middle boreal forests of the mountains (1), the southern boreal forests of the foothill of the Urals (2), the hemiboreal broadleaf-conifer forests (4), the hemiboreal pine and birch forests of the foothill of the Urals (1), the forest-steppe (1), and the northern and southern boreal forests (1). New records of Cantharellopsis prescotii and Hydropus subalpinus extend data on their distribution eastward to the Urals, while the others fill the gaps between localities in Europe and Asia. Ten species were recorded in anthropogenic habitats of the urban areas only.
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Herrmann, Steffen, Malgorzata Conder, and Peter Brang. "Totholzvolumen und -qualität in ausgewählten Schweizer Naturwaldreservaten." Schweizerische Zeitschrift fur Forstwesen 163, no. 6 (June 1, 2012): 222–31. http://dx.doi.org/10.3188/szf.2012.0222.
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Deadwood volume and quality in selected swiss natural forest reserves Deadwood is structurally and functionally important for forest ecosystems. To date, there are hardly any data on the amount of deadwood in Swiss natural forests which can serve as reference value for deadwood management in managed forests. In this study, deadwood volumes and qualities (sizes, broadleaf/conifer ratios, decomposition stages) from six natural forest reserves were analysed and compared with data from managed forests as well as from natural and virgin forests. An average of 69 m3/ha with a broadleaf proportion of 66% was calculated for the six reserves. Deadwood volume in relation to the total volume was 12% on average. Overall the volume of lying deadwood was double the volume of standing deadwood. The average proportion of large deadwood (diameter >30 cm) was 48% and was higher in snags (52%) than in lying deadwood (46%). Advanced stages of decomposition made up 53% of the lying deadwood. The volumes, sizes and decomposition stages varied greatly within the reserves. In comparison, in the Swiss forests altogether, there is less deadwood (21.5 m3/ha, 5% of total volume), the deadwood is thinner (35% large deadwood proportion) and less decayed (proportion of advanced stages of decomposition 10%). However, deadwood volumes in the reserves are considerably lower than those in European natural beech forests and beech virgin forests. The investigated reserves are therefore, 40 to 92 years after the last silvicultural intervention, only at the beginning of the process of acquiring a virgin forest character.
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Deng, Jiaojiao, You Yin, Jiyao Luo, Wenxu Zhu, and Yongbin Zhou. "Different revegetation types alter soil physical-chemical characteristics and fungal community in the Baishilazi Nature Reserve." PeerJ 6 (January 11, 2019): e6251. http://dx.doi.org/10.7717/peerj.6251.
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The effects of different revegetation types on soil physical–chemical characteristics and fungal community diversity and composition of soils sampled from five different revegetation types (JM, Juglans mandshurica; QM, Quercus mongolica; conifer-broadleaf forest (CB); LG, Larix gmelinii; PK, Pinus koraiensis) in the Baishilazi Nature Reserve were determined. Soil fungal communities were assessed employing ITS rRNA Illunima Miseq high-throughput sequencing. Responses of the soil fungi community to soil environmental factors were assessed through canonical correspondence analysis (CCA) and Pearson correlation analysis. The coniferous forests (L. gmelinii, P. koraiensis) and CB had reduced soil total carbon (C), total nitrogen (N), and available nitrogen (AN) values compared with the broadleaf forest (J. mandshurica, Q. mongolica). The average fungus diversity according to the Shannon, ACE, Chao1, and Simpson index were increased in the J. mandshurica site. Basidiomycota, Ascomycota, Zygomycota, and Rozellomycota were the dominant fungal taxa in this region. The phylum Basidiomycota was dominant in the Q. mongolica, CB, L. gmelinii, and P. koraiensis sites, while Ascomycota was the dominant phylum in the J. mandshurica site. The clear differentiation of fungal communities and the clustering in the heatmap and in non-metric multidimensional scaling plot showed that broadleaf forests, CB, and coniferous forests harbored different fungal communities. The results of the CCA showed that soil environmental factors, such as soil pH, total C, total N, AN, and available phosphorus (P) greatly influenced the fungal community structure. Based on our results, the different responses of the soil fungal communities to the different revegetation types largely dependent on different forest types and soil physicochemical characteristic in Baishilazi Nature Reserve.
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Deng, Jiaojiao, Wenxu Zhu, Yongbin Zhou, and You Yin. "Soil Organic Carbon Chemical Functional Groups under Different Revegetation Types Are Coupled with Changes in the Microbial Community Composition and the Functional Genes." Forests 10, no. 3 (March 8, 2019): 240. http://dx.doi.org/10.3390/f10030240.
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Different revegetatiom types can affect the chemical composition of soil organic carbon (SOC), soil microbial community and the functional genes related to carbon cycle. However, the relationships between SOC chemical functional groups and soil microbial communities and the functional genes remains poorly unclear under different revegetation types. Using the solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, we examined changes in the SOC chemical composition of five soils (0–10 cm depth) from Larix gmelinii Rupr. (LG), Pinus koraiensis Sieb. (PK), Quercus mongolica Fisch. (QM), Juglans mandshurica Maxim. (JM), and conifer-broadleaf forest (CB). And the soil microbial community genes related to metabolism of macro-molecular compounds were determined via whole genome shotgun based on Illumina HiSeq. Our results indicated that broadleaf forests (JM, QM) had increased the contents of soil total carbon (C), total nitrogen (N), dissolved organic carbon (DOC), and microbial biomass carbon (MBC), compared with coniferous forests (LG, PK) and the conifer-broadleaf forest (CB). While, the coniferous forests generated a lower O-alcoxyl C, a higher alkyl C, and the ratio of alkyl C/O-alkyl C than broadleaf forests. A total of four kingdoms were identified via whole metagenome shotgun sequencing, including eight archaea, 55 bacteria, 15 eukaryota, and two viruses, giving a total 80 phyla. The contents of alkyne C, phenolic C, methoxyl C, COO/NC=O, and alkyl C were strong related to the composition of soil microbial community and their contents illuminated a major part of the variation in soil microbial composition. We detected seven corresponding macro-molecular compounds of different organic carbon functional group, and 244 genes related to metabolism across all samples, and soil total C, total N, and DOC could be the main factors for microbial functional gene composition. Interestingly, the relative abundances of different SOC chemical functional groups, the phylogenetic distance for microbes, the genes of C cycling based on the KEGG database, and the relative abundance of genes related to metabolism of macro-molecular compounds of different SOC chemical functional groups under different revegetation types all could be divided into three groups, including PK plus LG, JM plus QM, and CB. Our results also illustrated that variations in SOC chemical functional groups were strongly associated with changes of soil microbial community taxa and functional genes, which might be affected by the changes of soil characteristics.
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Maleki, Kobra, Freddy Nguema Allogo, and Benoit Lafleur. "Natural Regeneration Following Partial and Clear-Cut Harvesting in Mature Aspen-Jack Pine Stands in Eastern Canada." Forests 11, no. 7 (July 8, 2020): 741. http://dx.doi.org/10.3390/f11070741.
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Over the last three decades, the ecological basis for the generalized use of even-aged silviculture in boreal forests has been increasingly challenged. In boreal mixed-wood landscapes, the diminishing proportion of conifers, to the benefit of intolerant hardwoods, has been a primary concern, coupled with the general rarefication of old-growth conifer-dominated stands. In this context, partial cutting, extended rotations and forest renewal techniques that eliminate or reduce regenerating hardwoods have been proposed as means of regaining greater conifer cover. As a result, experimentation and industrial application of various forms of both variable retention and partial harvesting are occurring across the commercial Canadian boreal forest. In this study, we compared the effects of two harvesting intensities, clearcutting and low-intensity partial cutting (removal of 25–31% of tree basal area), on hardwood and conifer regeneration levels 7–19 years following treatments in aspen (Populus tremuloides)-dominated stands and verified whether regeneration differences existed between micro-sites on and off machinery trails. The abundance of aspen regeneration increased with percent basal area removal and was positively correlated to the abundance of mature aspen prior to harvesting. The abundance of fir (Abies balsamea) regeneration after partial cutting was similar to controls and higher than after clear-cutting and was positively correlated with ground cover of mixed litter (i.e., mixture of needles and leaves) and negatively correlated with ground cover of broadleaf litter. These results suggest that it is possible in boreal mixed-woods to control aspen abundance and promote or maintain conifer regeneration through silvicultural treatments that limit canopy opening and promote mixed forest floor litter.
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Felton, Adam, Per-Ola Hedwall, Renats Trubins, Jakob Lagerstedt, Annika Felton, and Matts Lindbladh. "From mixtures to monocultures: Bird assemblage responses along a production forest conifer-broadleaf gradient." Forest Ecology and Management 494 (August 2021): 119299. http://dx.doi.org/10.1016/j.foreco.2021.119299.
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Jayathunga, Sadeepa, Toshiaki Owari, Satoshi Tsuyuki, and Yasumasa Hirata. "Potential of UAV photogrammetry for characterization of forest canopy structure in uneven-aged mixed conifer–broadleaf forests." International Journal of Remote Sensing 41, no. 1 (August 1, 2019): 53–73. http://dx.doi.org/10.1080/01431161.2019.1648900.
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Nainar, Anand, Koju Kishimoto, Koichi Takahashi, Mie Gomyo, and Koichiro Kuraji. "How Do Ground Litter and Canopy Regulate Surface Runoff?—A Paired-Plot Investigation after 80 Years of Broadleaf Forest Regeneration." Water 13, no. 9 (April 27, 2021): 1205. http://dx.doi.org/10.3390/w13091205.
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Relatively minimal attention has been given to the hydrology of natural broadleaf forests compared to conifer plantations in Japan. We investigated the impacts of ground litter removal and forest clearing on surface runoff using the paired runoff plot approach. Plot A (7.4 m2) was maintained as a control while plot B (8.1 m2) was manipulated. Surface runoff was measured by a tipping-bucket recorder, and rainfall by a tipping-bucket rain gauge. From May 2016 to July 2019, 20, 54, and 42 runoff events were recorded in the no-treatment (NT), litter removed before clearcutting (LRBC), and after clearcutting (AC) phases, respectively. Surface runoff increased 4× when moving from the NT to LRBC phase, and 4.4× when moving from the LRBC to AC phase. Antecedent precipitation index (API11) had a significant influence on surface runoff in the LRBC phase but not in the NT and AC phases. Surface runoff in the AC phase was high regardless of API11. The rainfall required for initiating surface runoff is 38% and 56% less when moving from the NT to LRBC, and LRBC to AC phases, respectively. Ground litter and canopy function to reduce surface runoff in regenerated broadleaf forests.
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Marchioro, Matteo, Davide Rassati, Massimo Faccoli, Kate Van Rooyen, Chantelle Kostanowicz, Vincent Webster, Peter Mayo, and Jon Sweeney. "Maximizing Bark and Ambrosia Beetle (Coleoptera: Curculionidae) Catches in Trapping Surveys for Longhorn and Jewel Beetles." Journal of Economic Entomology 113, no. 6 (September 23, 2020): 2745–57. http://dx.doi.org/10.1093/jee/toaa181.
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Abstract Bark and ambrosia beetles are commonly moved among continents within timber and fresh wood-packaging materials. Routine visual inspections of imported commodities are often complemented with baited traps set up in natural areas surrounding entry points. Given that these activities can be expensive, trapping protocols that attract multiple species simultaneously are needed. Here we investigated whether trapping protocols commonly used to detect longhorn beetles (Coleoptera: Cerambycidae) and jewel beetles (Coleoptera: Buprestidae) can be exploited also for detecting bark and ambrosia beetles. In factorial experiments conducted in 2016 both in Italy (seminatural and reforested forests) and Canada (mixed forest) we tested the effect of trap color (green vs purple), trap height (understory vs canopy), and attractive blend (hardwood-blend developed for broadleaf-associated wood-boring beetles vs ethanol in Italy; hardwood-blend vs softwood-blend developed for conifer-associated wood-boring beetles, in Canada) separately on bark beetles and ambrosia beetles, as well as on individual bark and ambrosia beetle species. Trap color affected catch of ambrosia beetles more so than bark beetles, with purple traps generally more attractive than green traps. Trap height affected both beetle groups, with understory traps generally performing better than canopy traps. Hardwood-blend and ethanol performed almost equally in attracting ambrosia beetles in Italy, whereas hardwood-blend and softwood-blend were more attractive to broadleaf-associated species and conifer-associated species, respectively, in Canada. In general, we showed that trapping variables suitable for generic surveillance of longhorn and jewel beetles may also be exploited for survey of bark and ambrosia beetles, but trapping protocols must be adjusted depending on the forest type.
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Axelson, Jodi N., Brad C. Hawkes, Lara van Akker, and René I. Alfaro. "Stand dynamics and the mountain pine beetle — 30 years of forest change in Waterton Lakes National Park, Alberta, Canada." Canadian Journal of Forest Research 48, no. 10 (October 2018): 1159–70. http://dx.doi.org/10.1139/cjfr-2018-0161.
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The mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) is a native bark beetle and a major disturbance agent in western North American forests. In the 1970s and 1980s, a MPB outbreak occurred in Waterton Lakes National Park (WLNP) in southwestern Alberta. The MPB outbreak resulted in variable levels of mortality of mature lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson), reducing density, volume, and basal area of overstory trees. By 2010, lodgepole pine was proportionally no longer the dominant overstory species, with increases in non-pine conifer and broadleaf species. The MPB susceptibility index decreased in most stands over time, especially in stands with the highest MPB-caused mortality. Downed woody material was characterized by fine and coarse fuel mass and volume, which both increased from 2002 to 2010, and the abundance of coarse fuels was highest in 2010, nearly 30 years after peak MPB activity. Density of understory saplings and small regeneration increased from 2002 to 2010 and was dominated by non-pine conifer and broadleaf species; lodgepole pine was nearly absent. Hierarchical clustering using 2010 MPB susceptibility and composition data characterized biological legacies remaining after the MPB outbreak. These legacies suggest multiple successional trajectories in WLNP dominated by species other than lodgepole pine. The MPB outbreak resulted in greater heterogeneity in composition and structure and suggests that stands have been resilient to this disturbance.
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Bansal, Sheel, Till Jochum, David A. Wardle, and Marie-Charlotte Nilsson. "The interactive effects of surface-burn severity and canopy cover on conifer and broadleaf tree seedling ecophysiology." Canadian Journal of Forest Research 44, no. 9 (September 2014): 1032–41. http://dx.doi.org/10.1139/cjfr-2014-0112.
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Fire has an important role for regeneration of many boreal forest tree species, and this includes both wildfire and prescribed burning following clear-cutting. Depending on the severity, fire can have a variety of effects on above- and below-ground properties that impact tree seedling establishment. Very little is known about the impacts of ground fire severity on post-fire seedling performance, or how the effects of fire severity interact with those of canopy structure. We conducted a full-factorial experiment that manipulated surface-burn severity (no burn; light, medium, or heavy burn; or scarification) and canopy (closed forest or open clear-cut) to reveal their interactive effects on ecophysiological traits of establishing broadleaf and conifer seedlings in a Swedish boreal forest. Medium and heavy surface burns increased seedling growth, photosynthesis, respiration, and foliar N and P concentrations, and these effects were most apparent in open clear-cuts. Growth rates of all species responded similarly to surface-burn treatments, although photosynthesis, foliar P, and specific leaf area were more responsive to burning treatments for broadleaf species than for conifers. Our study demonstrates that the positive impacts of fire on tree seedling physiology are dependent on a minimum severity threshold and are more effective when combined with clear-cutting.
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Seely, B., C. Hawkins, J. A. Blanco, C. Welham, and J. P. Kimmins. "Evaluation of a mechanistic approach to mixedwood modelling." Forestry Chronicle 84, no. 2 (April 1, 2008): 181–93. http://dx.doi.org/10.5558/tfc84181-2.
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Mixed conifer–broadleaf forests (mixedwoods), covering more than a third of the productive forest landbase in BC, are highly valuable both as sources of fibre and as areas rich in biodiversity. In recognition of the multiple benefits of this forest type, management paradigms have transitioned from a focus on promoting conifer plantations in mixedwood areas to the management of intimate mixtures. The exceptionally dynamic growth properties and species interactions in mixedwood forests present a challenge for projecting the growth and development of different types of mixedwoods and their response to different silviculture systems. Here we evaluate the ability of a mechanistic forest growth model (FORECAST) to project patterns of stand growth and dynamics in two mixedwood forest types subjected to different silvicultural treatments. Model output is compared against field measurements from long-term silviculture trials in the Sub Boreal Spruce (SBS)—18 years, and Interior Cedar Hemlock (ICH)—10 years, biogeoclimatic zones in British Columbia, Canada. FORECAST was able to reproduce patterns of growth response in both mixedwood forest types with reasonable accuracy. An analysis of the simulated relative impact of light and nutrient competition on growth dynamics and treatment response is provided. Results suggest that competition for both light and nutrients are important factors in the dynamics of these mixedwood forest types and that long-term response data and modelling are required to adequately assess the rotation-length effects of treatments on stand development. The analysis described herein provides a level of confidence for the use of the model as a decision-support tool in these ecosystem types, but more validation work should be conducted across a range of different mixedwood forest types and management interventions as long-term datasets become available. Key words: FORECAST, mixedwood management, model testing, process-based model, resource competition
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Stephens, Jaime L., Ian J. Ausprey, Nathaniel E. Seavy, and John D. Alexander. "Fire severity affects mixed broadleaf–conifer forest bird communities: Results for 9 years following fire." Condor 117, no. 3 (August 2015): 430–46. http://dx.doi.org/10.1650/condor-14-58.1.
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Huesca, Margarita, Mariano García, Keely L. Roth, Angeles Casas, and Susan L. Ustin. "Canopy structural attributes derived from AVIRIS imaging spectroscopy data in a mixed broadleaf/conifer forest." Remote Sensing of Environment 182 (September 2016): 208–26. http://dx.doi.org/10.1016/j.rse.2016.04.020.
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Namikawa, Kanji, Shingo Okamoto, and Junji Sano. "Edaphic controls on mosaic structure of the mixed deciduous broadleaf/conifer forest in northern Japan." Forest Ecology and Management 127, no. 1-3 (March 2000): 169–79. http://dx.doi.org/10.1016/s0378-1127(99)00128-0.
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Parent, Sylvain, and Christian Messier. "A simple and efficient method to estimate microsite light availability under a forest canopy." Canadian Journal of Forest Research 26, no. 1 (January 1, 1996): 151–54. http://dx.doi.org/10.1139/x26-017.
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This study presents a new, simple, and efficient method for estimating microsite light availability in the understory of a forest. The percentage of above-canopy photosynthetic photon flux density (%PPFD) transmitted above 16 microsites in the understory of a mixed conifer–broadleaf forest was measured every minute between 07:00 and 19:00 for both a completely overcast and a cloudless day. Instantaneous measures of %PPFD were also taken at different times on 3 overcast days. The instantaneous measures of %PPFD were strongly and directly related (P < 0.001) among themselves and with mean daily %PPFD values. These results demonstrate the usefulness of using an instantaneous measure of %PPFD taken under overcast sky conditions for estimating the mean daily %PPFD at any microsite under a forest canopy.
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Moe, Kyaw Thu, and Toshiaki Owari. "Sustainability of High-Value Timber Species in Mixed Conifer–Broadleaf Forest Managed under Selection System in Northern Japan." Forests 11, no. 5 (April 25, 2020): 484. http://dx.doi.org/10.3390/f11050484.
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Understanding the sustainability of high-value timber species in managed forests provides useful information for the management of these species in the long-run. Using nearly 50 years of census data in long-term permanent plots, we investigated the sustainability of three high-value timber species—monarch birch (Betula maximowicziana Regel), castor aralia (Kalopanax septemlobus (Thunb.) Koidz), and Japanese oak (Quercus crispula Blume)—in cool-temperate mixed forest under a selection system in northern Japan. We used stocking, demographic parameters, and species proportions of these species as measures of sustainability. Results showed that the tree density and basal area of the three high-value timber species increased during the study period. Moreover, the basal area increment of these species showed an increasing trend across census periods. However, while no significant differences in the tree mortality of these species were observed, the numbers of in-growth fluctuated across census periods. Increasing trends in species proportions of monarch birch and Japanese oak were observed. Even though there were some fluctuations across census periods, especially in smaller diameter classes, diameter distribution curves of high-value timber species followed a reversed J-shaped pattern. The results revealed that the sustainability measures of high-value timber species can be achieved in forest stands managed under single-tree selection system. In addition, the results also indicated the changing structure and composition of the forest stand. The stocking and basal area increment of conifers decreased while those of broadleaves increased. The proportion of conifers decreased to 33.01% in 2008–2016 from 48.35% in 1968–1978. The results of this study would be useful for adapting silvicultural practices and harvesting practices as well as for simulating various silvicultural and management options for high-value timber species.
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Pang, Yue, Jing Tian, Xuan Zhao, Zhi Chao, Yuchao Wang, Xinping Zhang, and Dexiang Wang. "The linkages of plant, litter and soil C:N:P stoichiometry and nutrient stock in different secondary mixed forest types in the Qinling Mountains, China." PeerJ 8 (June 3, 2020): e9274. http://dx.doi.org/10.7717/peerj.9274.
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Background Carbon (C), nitrogen (N) and phosphorus (P) stoichiometric ratios are important indicators of ecosystem function and productivity. However, few studies have assessed the nutrient relationship between plant, litter and soil, and the nutrient stock in different secondary mixed forest types. Methods We investigated the C, N and P concentrations and stoichiometric ratios in trees, understory plants, litter and soil layers in three different secondary mixed forest types (broadleaf mixed forests (BM), broadleaf-conifer mixed forests (BCM) and coniferous mixed forests (CM)) in the Qinling Mountains. Results The results showed that significant differences in C:N:P stoichiometry were detected in multiple organs in the vegetation layers in the different forest types. Trees, shrubs and herbs all allocated more N and P in leaves and had a higher N:P ratio in leaves than in other organs. The C concentrations, C:N ratios and C:P ratios of all tree organs showed a decreasing order: BM < BCM < CM, while the N and P concentrations showed an increasing order: BM > BCM > CM. For litter and soil, BM had generally higher N and P concentrations than those of BCM and CM. The highest N and P stock was in tree branches-not in the stem, which had the highest biomass (except for P in CM). Compared with other forest types, CM stored more nutrients in the labile litter layer, while BM stored more nutrients in the stable soil layer. The net ecosystem nutrient element stock in BM was generally higher than that in BCM and CM. The C, N and P concentrations and stoichiometry in the plant organs, litter and soil were significantly correlated. Conclusion Our findings demonstrate that nutrient concentrations in plant organs, litter and soil are tightly linked in secondary mixed forests.
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Jackson, Toby D., Sarab Sethi, Ebba Dellwik, Nikolas Angelou, Amanda Bunce, Tim van Emmerik, Marine Duperat, et al. "The motion of trees in the wind: a data synthesis." Biogeosciences 18, no. 13 (July 6, 2021): 4059–72. http://dx.doi.org/10.5194/bg-18-4059-2021.
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Abstract. Interactions between wind and trees control energy exchanges between the atmosphere and forest canopies. This energy exchange can lead to the widespread damage of trees, and wind is a key disturbance agent in many of the world's forests. However, most research on this topic has focused on conifer plantations, where risk management is economically important, rather than broadleaf forests, which dominate the forest carbon cycle. This study brings together tree motion time-series data to systematically evaluate the factors influencing tree responses to wind loading, including data from both broadleaf and coniferous trees in forests and open environments. We found that the two most descriptive features of tree motion were (a) the fundamental frequency, which is a measure of the speed at which a tree sways and is strongly related to tree height, and (b) the slope of the power spectrum, which is related to the efficiency of energy transfer from wind to trees. Intriguingly, the slope of the power spectrum was found to remain constant from medium to high wind speeds for all trees in this study. This suggests that, contrary to some predictions, damping or amplification mechanisms do not change dramatically at high wind speeds, and therefore wind damage risk is related, relatively simply, to wind speed. Conifers from forests were distinct from broadleaves in terms of their response to wind loading. Specifically, the fundamental frequency of forest conifers was related to their size according to the cantilever beam model (i.e. vertically distributed mass), whereas broadleaves were better approximated by the simple pendulum model (i.e. dominated by the crown). Forest conifers also had a steeper slope of the power spectrum. We interpret these finding as being strongly related to tree architecture; i.e. conifers generally have a simple shape due to their apical dominance, whereas broadleaves exhibit a much wider range of architectures with more dominant crowns.
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Lin, Chinsu, Siao-En Ma, Li-Ping Huang, Chung-I. Chen, Pei-Ting Lin, Zhih-Kai Yang, and Kuan-Ting Lin. "Generating a Baseline Map of Surface Fuel Loading Using Stratified Random Sampling Inventory Data through Cokriging and Multiple Linear Regression Methods." Remote Sensing 13, no. 8 (April 17, 2021): 1561. http://dx.doi.org/10.3390/rs13081561.
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Surface fuel loading is a key factor in controlling wildfires and planning sustainable forest management. Spatially explicit maps of surface fuel loading can highlight the risks of a forest fire. Geospatial information is critical in enabling careful use of deliberate fire setting and also helps to minimize the possibility of heat conduction over forest lands. In contrast to lidar sensing and/or optical sensing based methods, an approach of integrating in-situ fuel inventory data, geospatial interpolation techniques, and multiple linear regression methods provides an alternative approach to surface fuel load estimation and mapping over mountainous forests. Using a stratified random sampling based inventory and cokriging analysis, surface fuel loading data of 120 plots distributed over four kinds of fuel types were collected in order to develop a total surface fuel loading model (lntSFL-BioTopo model) and a fine surface fuel model (lnfSFL-BioTopo model) for generating tSFL and fSFL maps. Results showed that the combination of topographic parameters such as slope, aspect, and their cross products and the fuel types such as pine stand, non-pine conifer stand, broadleaf stand, and conifer–broadleaf mixed stand was able to appropriately describe the changes in surface fuel loads over a forest with diverse terrain morphology. Based on a cross-validation method, the estimation of tSFL and fSFL of the study site had an RMSE of 3.476 tons/ha and 3.384 tons/ha, respectively. In contrast to the average loading of all inventory plots, the estimation for tSFL and fSFL had a relative error of 38% (PRMSE). The reciprocal of estimation bias of both SFL-BioTopo models tended to be an exponential growth function of the amount of surface fuel load, indicating that the estimation accuracy of the proposed method is likely to be improved with further study. In the regression modeling, a natural logarithm transformation of the surface fuel loading prevented the outcome of negative estimates and thus improved the estimation. Based on the results, this paper defined a minimum sampling unit (MSU) as the area for collecting surface fuels for interpolation using a cokriging model. Allocating the MSUs at the boundary and center of a plot improved surface fuel load prediction and mapping.
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Seavy, Nathaniel E., and John D. Alexander. "Interactive effects of vegetation structure and composition describe bird habitat associations in mixed broadleaf-conifer forest." Journal of Wildlife Management 75, no. 2 (February 2011): 344–52. http://dx.doi.org/10.1002/jwmg.37.
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Jackson, T., A. Shenkin, J. Moore, A. Bunce, T. van Emmerik, B. Kane, D. Burcham, et al. "An architectural understanding of natural sway frequencies in trees." Journal of The Royal Society Interface 16, no. 155 (June 2019): 20190116. http://dx.doi.org/10.1098/rsif.2019.0116.
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The relationship between form and function in trees is the subject of a longstanding debate in forest ecology and provides the basis for theories concerning forest ecosystem structure and metabolism. Trees interact with the wind in a dynamic manner and exhibit natural sway frequencies and damping processes that are important in understanding wind damage. Tree-wind dynamics are related to tree architecture, but this relationship is not well understood. We present a comprehensive view of natural sway frequencies in trees by compiling a dataset of field measurement spanning conifers and broadleaves, tropical and temperate forests. The field data show that a cantilever beam approximation adequately predicts the fundamental frequency of conifers, but not that of broadleaf trees. We also use structurally detailed tree dynamics simulations to test fundamental assumptions underpinning models of natural frequencies in trees. We model the dynamic properties of greater than 1000 trees using a finite-element approach based on accurate three-dimensional model trees derived from terrestrial laser scanning data. We show that (1) residual variation, the variation not explained by the cantilever beam approximation, in fundamental frequencies of broadleaf trees is driven by their architecture; (2) slender trees behave like a simple pendulum, with a single natural frequency dominating their motion, which makes them vulnerable to wind damage and (3) the presence of leaves decreases both the fundamental frequency and the damping ratio. These findings demonstrate the value of new three-dimensional measurements for understanding wind impacts on trees and suggest new directions for improving our understanding of tree dynamics from conifer plantations to natural forests.
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Simard, Suzanne W., Shannon M. Hagerman, Donald L. Sachs, Jean L. Heineman, and W. Jean Mather. "Conifer growth, Armillaria ostoyae root disease, and plant diversity responses to broadleaf competition reduction in mixed forests of southern interior British Columbia." Canadian Journal of Forest Research 35, no. 4 (April 1, 2005): 843–59. http://dx.doi.org/10.1139/x05-010.
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Broadleaf trees are routinely removed from conifer plantations during vegetation management treatments, but whether the removal increases tree productivity or affects root disease and plant diversity is unknown. The effects of manual and chemical reduction of paper birch (Betula papyrifera Marsh.) and trembling aspen (Populus tremuloides Michx.) on conifer survival, growth, root disease incidence, and plant community diversity were investigated for 5 years in Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) plantations in southern interior British Columbia. Broadleaves were reduced by manual, girdling, and cut-stump glyphosate treatments for 5 years but most severely following cut-stump glyphosate and with a delay due to slow death following girdling. Conifer survival was reduced for 35 years following manual cutting or girdling of birch because of a 1.5- to 4-fold increase in mortality due to Armillaria ostoyae (Romagn.) Herink, but this did not occur following cut-stump glyphosate treatment of birch or manual cutting of aspen. Conifer diameter increased with treatment intensity and productivity of the vegetation complex. Competition thresholds were identified for diameter but not survival, although Armillaria-caused mortality tended to increase near the minimum growth threshold. Structural diversity increased following manual cutting and cut-stump glyphosate because birch dominants were removed and understory layers increased, but species richness and diversity were unaffected. Forest managers can expect increased conifer growth with birch removal but also small increases in mortality due to Armillaria ostoyae root disease following manual treatments and loss of large birch trees in all treatments.
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Liu, Qiang, Yue Sun, Gerong Wang, Fushan Cheng, and Fucai Xia. "Short-term effects of thinning on the understory natural environment of mixed broadleaf-conifer forest in Changbai Mountain area, Northeast China." PeerJ 7 (July 26, 2019): e7400. http://dx.doi.org/10.7717/peerj.7400.
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Background The understory natural environment is critical in affecting the succession and recovery process of vegetation, stand structure, and species composition of forest. The thinning intensity could significantly change the forest microclimates and soil properties, therefore, to analyze the effects of thinning intensity on the understory natural environment of forest is of important significance for promoting the ecological benefits of thinning. Methods A total of 16 fixed sample plots with different thinning intensities were established in the mixed broadleaf-conifer forest in Jiaohe, situated in Changbai Mountain area, Northeast China, and the forest microclimates and soil properties were investigated after 4 years since the establishment of the sample plots. Results The results showed that the high intensity thinning significantly decreased the leaf area index from 4.13 (unthinned plot) to 2.21 (high intensity thinned plot), and the air temperature was increased by thinning from May to July. Comparing with the unthinned plot, thinning caused a rise of temperature (ranging from 2.11 to 6.74 °C, depending on the intensity of thinning) in May. However, it showed cooling effect in September and October. Besides, the air moisture of thinning plots was lower than the control plot in May and October, when the density of leaves is lower in the forest, and it even decreased 20.27% after thinning. The thinning intensity had no significantly effect on water content and organic carbon in forest soils, and only the bulk density in the top-layer soils in high intensity thinning plot was remarkably increased. Total nitrogen in soil was increased by different intensities of thinning, and the availability of nutrients for nitrogen, phosphorus and potassium in some soils were also affected.
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Abdollahnejad, Azadeh, and Dimitrios Panagiotidis. "Tree Species Classification and Health Status Assessment for a Mixed Broadleaf-Conifer Forest with UAS Multispectral Imaging." Remote Sensing 12, no. 22 (November 12, 2020): 3722. http://dx.doi.org/10.3390/rs12223722.
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Automatic discrimination of tree species and identification of physiological stress imposed on forest trees by biotic factors from unmanned aerial systems (UAS) offers substantial advantages in forest management practices. In this study, we aimed to develop a novel workflow for facilitating tree species classification and the detection of healthy, unhealthy, and dead trees caused by bark beetle infestation using ultra-high resolution 5-band UAS bi-temporal aerial imagery in the Czech Republic. The study is divided into two steps. We initially classified the tree type, either as broadleaf or conifer, and we then classified trees according to the tree type and health status, and subgroups were created to further classify trees (detailed classification). Photogrammetric processed datasets achieved by the use of structure-from-motion (SfM) imaging technique, where resulting digital terrain models (DTMs), digital surface models (DSMs), and orthophotos with a resolution of 0.05 m were utilized as input for canopy spectral analysis, as well as texture analysis (TA). For the spectral analysis, nine vegetation indices (VIs) were applied to evaluate the amount of vegetation cover change of canopy surface between the two seasons, spring and summer of 2019. Moreover, 13 TA variables, including Mean, Variance, Entropy, Contrast, Heterogeneity, Homogeneity, Angular Second Moment, Correlation, Gray-level Difference Vector (GLDV) Angular Second Moment, GLDV Entropy, GLDV Mean, GLDV Contrast, and Inverse Difference, were estimated for the extraction of canopy surface texture. Further, we used the support vector machine (SVM) algorithm to conduct a detailed classification of tree species and health status. Our results highlighted the efficiency of the proposed method for tree species classification with an overall accuracy (OA) of 81.18% (Kappa: 0.70) and health status assessment with an OA of 84.71% (Kappa: 0.66). While SVM proved to be a good classifier, the results also showed that a combination of VI and TA layers increased the OA by 4.24%, providing a new dimension of information derived from UAS platforms. These methods could be used to quickly evaluate large areas that have been impacted by biological disturbance agents for mapping and detection, tree inventory, and evaluating habitat conditions at relatively low costs.
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Jakoby, Gilad, Ido Rog, Shacham Megidish, and Tamir Klein. "Enhanced root exudation of mature broadleaf and conifer trees in a Mediterranean forest during the dry season." Tree Physiology 40, no. 11 (July 24, 2020): 1595–605. http://dx.doi.org/10.1093/treephys/tpaa092.
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Abstract Root exudates are part of the rhizodeposition process, which is the major source of soil organic carbon (C) released by plant roots. This flux of C is believed to have profound effects on C and nutrient cycling in ecosystems. The quantity of root exudates depends on the plant species, the period throughout the year, and external biotic and abiotic factors. Since root exudates of mature trees are difficult to collect in field conditions, very little is known about their flux, especially in water-limited ecosystems, such as the seasonally hot and dry Mediterranean maquis. Here, we collected exudates from DNA-identified roots in the forest from the gymnosperm Cupressus sempervirens L. and the evergreen angiosperm Pistacia lentiscus L. by 48-h incubations on a monthly temporal resolution throughout the year. We examined relationships of the root exudate C flux to abiotic parameters of the soil (water content, water potential, temperature) and atmosphere (vapor pressure deficit, temperature). We also studied relationships to C fluxes through the leaves as indicators of tree C balance. Root exudation rates varied significantly along the year, increasing from 6 μg C cm −2 root day−1 in both species in the wet season to 4- and 11-fold rates in Pistacia and Cupressus, respectively, in the dry season. A stepwise linear mixed-effects model showed that the three soil parameters were the most influential on exudation rates. Among biotic factors, there was a significant negative correlation of exudation rate with leaf assimilation in Cupressus and a significant negative correlation with leaf respiration in Pistacia. Our observation of enhanced exudation flux during the dry season indicates that exudation dynamics in the field are less sensitive to the low tree C availability in the dry season. The two key Mediterranean forest species seem to respond to seasonal changes in the rhizosphere such as drying and warming, and therefore invest C in the rhizosphere under seasonal drought.
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Jayathunga, Sadeepa, Toshiaki Owari, and Satoshi Tsuyuki. "Analysis of forest structural complexity using airborne LiDAR data and aerial photography in a mixed conifer–broadleaf forest in northern Japan." Journal of Forestry Research 29, no. 2 (June 9, 2017): 479–93. http://dx.doi.org/10.1007/s11676-017-0441-4.
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Leonelli, Giovanni, Anna Coppola, Maria Cristina Salvatore, Carlo Baroni, Giovanna Battipaglia, Tiziana Gentilesca, Francesco Ripullone, et al. "Climate signals in a multispecies tree-ring network from central and southern Italy and reconstruction of the late summer temperatures since the early 1700s." Climate of the Past 13, no. 11 (November 2, 2017): 1451–71. http://dx.doi.org/10.5194/cp-13-1451-2017.
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Abstract. A first assessment of the main climatic drivers that modulate the tree-ring width (RW) and maximum latewood density (MXD) along the Italian Peninsula and northeastern Sicily was performed using 27 forest sites, which include conifers (RW and MXD) and broadleaves (only RW). Tree-ring data were compared using the correlation analysis of the monthly and seasonal variables of temperature, precipitation and standardized precipitation index (SPI, used to characterize meteorological droughts) against each species-specific site chronology and against the highly sensitive to climate (HSTC) chronologies (based on selected indexed individual series). We find that climate signals in conifer MXD are stronger and more stable over time than those in conifer and broadleaf RW. In particular, conifer MXD variability is directly influenced by the late summer (August, September) temperature and is inversely influenced by the summer precipitation and droughts (SPI at a timescale of 3 months). The MXD sensitivity to August–September (AS) temperature and to summer drought is mainly driven by the latitudinal gradient of summer precipitation amounts, with sites in the northern Apennines showing stronger climate signals than sites in the south. Conifer RW is influenced by the temperature and drought of the previous summer, whereas broadleaf RW is more influenced by summer precipitation and drought of the current growing season. The reconstruction of the late summer temperatures for the Italian Peninsula for the past 300 years, based on the HSTC chronology of conifer MXD, shows a stable model performance that underlines periods of climatic cooling (and likely also wetter conditions) in 1699, 1740, 1814, 1914 and 1938, and follows well the variability of the instrumental record and of other tree-ring-based reconstructions in the region. Considering a 20-year low-pass-filtered series, the reconstructed temperature record consistently deviates < 1 °C from the instrumental record. This divergence may also be due to the precipitation patterns and drought stresses that influence the tree-ring MXD at our study sites. The reconstructed late summer temperature variability is also linked to summer drought conditions and it is valid for the west–east oriented region including Sardinia, Sicily, the Italian Peninsula and the western Balkan area along the Adriatic coast.
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Moe, Kyaw Thu, Toshiaki Owari, Naoyuki Furuya, Takuya Hiroshima, and Junko Morimoto. "Application of UAV Photogrammetry with LiDAR Data to Facilitate the Estimation of Tree Locations and DBH Values for High-Value Timber Species in Northern Japanese Mixed-Wood Forests." Remote Sensing 12, no. 17 (September 3, 2020): 2865. http://dx.doi.org/10.3390/rs12172865.
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High-value timber species play an important economic role in forest management. The individual tree information for such species is necessary for practical forest management and for conservation purposes. Digital aerial photogrammetry derived from an unmanned aerial vehicle (UAV-DAP) can provide fine spatial and spectral information, as well as information on the three-dimensional (3D) structure of a forest canopy. Light detection and ranging (LiDAR) data enable area-wide 3D tree mapping and provide accurate forest floor terrain information. In this study, we evaluated the potential use of UAV-DAP and LiDAR data for the estimation of individual tree location and diameter at breast height (DBH) values of large-size high-value timber species in northern Japanese mixed-wood forests. We performed multiresolution segmentation of UAV-DAP orthophotographs to derive individual tree crown. We used object-based image analysis and random forest algorithm to classify the forest canopy into five categories: three high-value timber species, other broadleaf species, and conifer species. The UAV-DAP technique produced overall accuracy values of 73% and 63% for classification of the forest canopy in two forest management sub-compartments. In addition, we estimated individual tree DBH Values of high-value timber species through field survey, LiDAR, and UAV-DAP data. The results indicated that UAV-DAP can predict individual tree DBH Values, with comparable accuracy to DBH prediction using field and LiDAR data. The results of this study are useful for forest managers when searching for high-value timber trees and estimating tree size in large mixed-wood forests and can be applied in single-tree management systems for high-value timber species.
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Cook, Rachel L., Dan Binkley, João Carlos T. Mendes, and Jose Luiz Stape. "Soil carbon stocks and forest biomass following conversion of pasture to broadleaf and conifer plantations in southeastern Brazil." Forest Ecology and Management 324 (July 2014): 37–45. http://dx.doi.org/10.1016/j.foreco.2014.03.019.
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Jaramillo, Fernando, Neil Cory, Berit Arheimer, Hjalmar Laudon, Ype van der Velde, Thomas B. Hasper, Claudia Teutschbein, and Johan Uddling. "Dominant effect of increasing forest biomass on evapotranspiration: interpretations of movement in Budyko space." Hydrology and Earth System Sciences 22, no. 1 (January 23, 2018): 567–80. http://dx.doi.org/10.5194/hess-22-567-2018.
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Abstract. During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s) of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961–2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60 % of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large-scale evapotranspiration changes in Swedish forests.
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Cárcamo, H. A., T. A. Abe, C. E. Prescott, F. B. Holl, and C. P. Chanway. "Influence of millipedes on litter decomposition, N mineralization, and microbial communities in a coastal forest in British Columbia, Canada." Canadian Journal of Forest Research 30, no. 5 (May 1, 2000): 817–26. http://dx.doi.org/10.1139/x00-014.
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Laboratory experiments were conducted with the millipede Harpaphe haydeniana haydeniana Wood (Polydesmida: Xystodesmidae) to determine (i) its litter feeding preferences, (ii) rates of leaf litter consumption, (iii) feeding effects on available nitrogen, and (iv) functional microbial diversity. The millipede exhibited a preference for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and, to a lesser extent, Sitka spruce (Picea sitchensis (Bong.) Carrière) litter compared with western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don) litter when given a choice. When only one litter type was provided, millipedes consumed considerably more western redcedar than Douglas-fir, Sitka spruce, or western hemlock. Among the six broadleaf species tested, paper birch (Betula papyrifera Marsh.), bigleaf maple (Acer macrophyllum Pursh), vine maple (Acer circinatum Pursh), and red alder (Alnus rubra Bong.) were consumed at much higher rates than swordfern (Polystichum munitum (Kaulf.) Presl.) or salal (Gaultheria shallon Pursh). Daily rates of conifer litter consumption ranged between 10 and 20% of the millipede's fresh biomass and may translate to 36% of the annual litter fall. Our results suggest that transformation of conifer litter into millipede frass can increase rates of litter decomposition and N mineralization, as well as influence microbial activity and diversity in coastal forests.
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Ellis, Tana M., Andrew J. Kroll, and Matthew G. Betts. "Early seral hardwood vegetation increases adult and fledgling bird abundance in Douglas-fir plantations of the Oregon Coast Range, USA." Canadian Journal of Forest Research 42, no. 5 (May 2012): 918–33. http://dx.doi.org/10.1139/x2012-035.
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Recent evidence suggests that population declines of bird species associated with early-successional forest conditions may be associated with reduced quality of breeding habitat. Increasing intensity of forest management on private lands and decreased harvest rates on federal lands in the Pacific Northwest, USA, have resulted in a loss of diverse young forest stands, typically called early seral forest. Previous studies suggest that the amount of early seral broadleaf cover within conifer forests is linked to the composition of foliage-gleaning bird communities. However, information regarding productivity and juvenile use of post-breeding habitat in highly modified plantation habitat is lacking. We examined the relationship between vegetation structure resulting from intensive forest management practices and the abundance of five species of leaf-gleaning, neotropical migrants: orange-crowned warbler ( Oreothlypis celata (Say, 1823)), Wilson’s warbler ( Wilsonia pusilla (A. Wilson, 1811)), MacGillivray’s warbler ( Oporornis tolmiei (J.K. Townsend, 1839)), Swainson’s thrush ( Catharus ustulatus (Nuttall, 1840)), and black-headed grosbeak ( Pheucticus melanocephalus (Swainson, 1827)). All species, except MacGillivray’s warbler, showed positive associations with the amount of early seral hardwood cover as fledglings, breeding adults, or both. However, the relative magnitude of these associations varied, suggesting that other factors may also have influenced avian responses. Abundances of breeding pairs and young are likely to show positive responses to management practices that increase early seral hardwood cover in regenerating stands. If adopted at landscape and regional scales, such practices may positively influence population trends of several declining bird species.
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Elliot, M. B., B. Striewski, J. R. Flenley, and D. G. Sutton. "Palynological and Sedimentological Evidence for a Radiocarbon Chronology of Environmental Change and Polynesian Deforestation from Lake Taumatawhana, Northland, New Zealand." Radiocarbon 37, no. 3 (1995): 899–916. http://dx.doi.org/10.1017/s0033822200014983.
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We present pollen diagrams and sedimentological analyses from a lake site within an extensive dune system on the Aupouri Peninsula, Northland. Five thousand years ago, a regional Agathis australis–podocarp-broadleaf forest dominated the vegetation, which manifested an increasing preponderance of conifer species. Climate was cooler and drier than at present. From ca. 3400 bp, warmth-loving species such as A. australis and drought-intolerant species, Dacrydium cupressinum and Ascarina lucida, became common, implying a warm and moist climate. The pollen record also suggests a windier climate. The most significant event in the record, however, occurred after ca. 900 bp (800 cal bp) when anthropogenic deforestation commenced. A dramatic decline in forest taxa followed, accompanied by the establishment of a Pteridium–esculentum-dominated community. Fire almost certainly caused this, evidenced by a dramatic increase of charcoal. Sedimentological evidence for this site indicates a relatively stable environment before humans arrived and an increasingly unstable environment with frequent erosional events after human contact.
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Chandler, J. R., M. G. Schmidt, and S. Dragicevic. "Spatial patterns of forest floor properties and litterfall amounts associated with bigleaf maple in conifer forest of southwestern British Columbia." Canadian Journal of Soil Science 88, no. 3 (May 2, 2008): 295–313. http://dx.doi.org/10.4141/cjss07040.
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This study was aimed at detecting the spatial characteristics of forest floor properties and litterfall amounts related to bigleaf maple (Acer macrophyllum Pursh) within conifer forest. Two 36-m × 36-m plots, centered on individual dominant bigleaf maple stems, were sampled at 129 systematic locations and tested for forest floor pH, cation exchange capacity, exchangeable cations, and mineralizable N. Tree stem location, forest floor horizon depths and litterfall amounts were measured. The kriging approach was used to visualize overall spatial patterns, Moran's I was used to give a global measure of spatial autocorrelation over the sampled region, and local indicators of spatial association (LISA) was used to detect and locate significant spatial clustering of similar values at the local scale. Most soil chemical properties had higher values in locations adjacent to the bigleaf maple stem, up to distances of 2.5 m from the stem on both study plots, and all exchangeable cations were positively spatially autocorrelated (P < 0.05) up to distances of 4 m. The majority of bigleaf maple litter (84% on plot 1, 92% on plot 2) was found to be deposited directly beneath the canopy extent. This study provides an understanding of the underlying spatial patterns of bigleaf maple influence on soil properties at plot scale. Key words: Bigleaf maple, spatial analysis, broadleaf species, plant-soil interactions local indicators of spatial association, forest floor