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Holzner, Anna, D. Mark Rayan, Jonathan Moore, Cedric Kai Wei Tan, Laura Clart, Lars Kulik, Hjalmar Kühl, Nadine Ruppert und Anja Widdig. „Occupancy of wild southern pig-tailed macaques in intact and degraded forests in Peninsular Malaysia“. PeerJ 9 (14.12.2021): e12462. http://dx.doi.org/10.7717/peerj.12462.
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Deforestation is a major threat to terrestrial tropical ecosystems, particularly in Southeast Asia where human activities have dramatic consequences for the survival of many species. However, responses of species to anthropogenic impact are highly variable. In order to establish effective conservation strategies, it is critical to determine a species’ ability to persist in degraded habitats. Here, we used camera trapping data to provide the first insights into the temporal and spatial distribution of southern pig-tailed macaques (Macaca nemestrina, listed as ‘Vulnerable’ by the IUCN) across intact and degraded forest habitats in Peninsular Malaysia, with a particular focus on the effects of clear-cutting and selective logging on macaque occupancy. Specifically, we found a 10% decline in macaque site occupancy in the highly degraded Pasoh Forest Reserve from 2013 to 2017. This may be strongly linked to the macaques’ sensitivity to intensive disturbance through clear-cutting, which significantly increased the probability that M. nemestrina became locally extinct at a previously occupied site. However, we found no clear relationship between moderate disturbance, i.e., selective logging, and the macaques’ local extinction probability or site occupancy in the Pasoh Forest Reserve and Belum-Temengor Forest Complex. Further, an identical age and sex structure of macaques in selectively logged and completely undisturbed habitat types within the Belum-Temengor Forest Complex indicated that the macaques did not show increased mortality or declining birth rates when exposed to selective logging. Overall, this suggests that low to moderately disturbed forests may still constitute valuable habitats that support viable populations of M. nemestrina, and thus need to be protected against further degradation. Our results emphasize the significance of population monitoring through camera trapping for understanding the ability of threatened species to cope with anthropogenic disturbance. This can inform species management plans and facilitate the development of effective conservation measures to protect biodiversity.
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Flaspohler, David J., Casey J. FisherHuckins, Brian R. Bub und Peter J. van Dusen. „Temporal Patterns in Aquatic and Avian Communities Following Selective Logging in the Upper Great Lakes Region“. Forest Science 48, Nr. 2 (01.05.2002): 339–49. http://dx.doi.org/10.1093/forestscience/48.2.339.
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Abstract We surveyed populations of birds, fish, and aquatic macroinvertebrates in and along riparian systems within northern and mixed-hardwood forests that varied in time since last selection logging. Thirteen headwater stream sites from the Otter River watershed in Michigan's Upper Peninsula were included in the study. We detected a significant negative correlation between a standard index of habitat quality for coldwater streams (Great Lakes Environmental Assessment Section [GLEAS]) and time since last selective logging. Brook char (Salvelinus fontinalis Mitch.) abundance was also negatively correlated with year of forest cut as was the abundance of selected aquatic macroinvertebrate orders (Ephemeroptera, Plecoptera, and Trichoptera) that are sensitive to anthropogenic disturbance. Thus, relative to more recently logged stands, stands with older cuts had higher indices of habitat quality, more brook char, and the dominant aquatic macroinvertebrates tended to be those generally associated with higher quality coldwater streams. In contrast, bird species richness was positively related to year of last selective logging. As expected, basal area was lower and ground cover was greater in more recently logged stands. Thus, bird species richness was higher in stands with less basal area (recent cuts) than in stands with more basal area (older cuts). Percent ground cover showed a strong positive correlation with bird species richness. Twelve bird species were detected only in recently logged (since 1990) stands. The results of this multitaxa study suggest that selective logging of riparian forests is associated with changes in local animal abundance and diversity, and these effects appear to persist for approximately 30 yr postharvest. FOR. SCI. 48(2):339–349.
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Scheffler, Pamela Y. „Dung beetle (Coleoptera: Scarabaeidae) diversity and community structure across three disturbance regimes in eastern Amazonia“. Journal of Tropical Ecology 21, Nr. 1 (Januar 2005): 9–19. http://dx.doi.org/10.1017/s0266467404001683.
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Anthropogenic disturbance in Amazonian forests has increased dramatically since the early 1980s and forest disturbance is expected to continue in the early twenty-first century. Logging and conversion to pasture for cattle are two of the largest causes of forest disturbance and destruction. This study examined the distribution and diversity of dung beetles (Coleoptera: Scarabaeidae) in intact forest and under three disturbance regimes (selective logging, clear-cutting and pasture) in a forest tract in southern Pará state, Brazil. Dung beetles were collected using faeces-baited pitfall traps, then identified, measured and weighed. Principal Components Analyses and the Sørensen's Index indicated that the intact and selectively logged areas were similar in terms of species composition but that the pasture areas and clear-cut areas had substantially different groups of species. Beetle size and diversity (as measured by species richness, Shannon index and Simpson's index) were lower in clear-cuts and pasture than in intact forest. The selectively logged forest was no less diverse than intact forest, and beetles were the same size or larger than those in intact forest. Total beetle biomass, however, was highest in the pasture due to the abundance of small-bodied beetles in this habitat. While the fact that selective logging has a relatively minor impact on the dung beetle community is heartening, the projected increase in the amount of highly disturbed landscape in Amazonia is expected to have a severe impact on dung beetle biodiversity in the region.
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Hearn, Andrew J., Joanna Ross, Henry Bernard, Soffian A. Bakar, Benoit Goossens, Luke T. B. Hunter und David W. Macdonald. „Responses of Sunda clouded leopard Neofelis diardi population density to anthropogenic disturbance: refining estimates of its conservation status in Sabah“. Oryx 53, Nr. 4 (27.09.2017): 643–53. http://dx.doi.org/10.1017/s0030605317001065.
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AbstractExtensive areas of tropical forests have been, and continue to be, disturbed as a result of selective timber extraction. Although such anthropogenic disturbance typically results in the loss of biodiversity, many species persist, and their conservation in production landscapes could be enhanced by a greater understanding of how biodiversity responds to forest management practices. We conducted intensive camera-trap surveys of eight protected forest areas in Sabah, Malaysian Borneo, and developed estimates of Sunda clouded leopard Neofelis diardi population density from spatially explicit capture–recapture analyses of detection data to investigate how the species’ abundance varies across the landscape and in response to anthropogenic disturbance. Estimates of population density from six forest areas were 1.39–3.10 individuals per 100 km2. Our study provides the first evidence that the population density of the Sunda clouded leopard is negatively affected by hunting pressure and forest fragmentation, and that among selectively logged forests, time since logging is positively associated with abundance. We argue that these negative anthropogenic impacts could be mitigated with improved logging practices, such as reducing the access of poachers by effective gating and destruction of road access points, and by the deployment of anti-poaching patrols. By calculating a weighted mean population density estimate from estimates developed here and from the literature, and by extrapolating this value to an estimate of current available habitat, we estimate there are 754 (95% posterior interval 325–1,337) Sunda clouded leopards in Sabah.
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Yu, Jingjing, Wei Cong, Yi Ding, Lixiao Jin, Jing Cong und Yuguang Zhang. „Interkingdom Plant–Soil Microbial Ecological Network Analysis under Different Anthropogenic Impacts in a Tropical Rainforest“. Forests 13, Nr. 8 (23.07.2022): 1167. http://dx.doi.org/10.3390/f13081167.
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Plants and their associated soil microorganisms interact with each other and form complex relationships. The effects of slash-and-burn agriculture and logging on aboveground plants and belowground microorganisms have been extensively studied, but research on plant–microbial interkingdom ecological networks is lacking. In this study, using old growth forest as a control, we used metagenomic data (ITS and 16S rRNA gene amplified sequences) and plant data to obtain interdomain species association patterns for three different soil disturbance types (slash-and-burn, clear cutting and selective cutting) in a tropical rainforest based on interdomain ecological network (IDEN) analysis. Results showed that the soil bacterial–fungal and plant–microbe ecological networks had different topological properties among the three forest disturbance types compared to old growth forest. More nodes, links, higher modularity and negative proportion were found in the selective cutting stand, indicating higher stability with increasing antagonistic relationships and niche differentiation. However, the area of slash-and-burn forest yield opposite results. Network module analysis indicated that different keystone species were found in the four forest types, suggesting alternative stable states among them. Different plant species had more preferential associations with specific fungal taxa than bacterial taxa at the genus level and plant–microbe associations lagged behind bacterial–fungal associations. Overall, compared with old growth forests, the bacterial–fungal and plant–microbe ecological networks in the slash-and-burn and clear cutting stands were simpler, while the network in the selective cutting stand was more complex. Understanding the relationships between aboveground plants and belowground microorganisms under differing disturbance patterns in natural ecosystems will help in better understanding the surrounding ecosystem functions of ecological networks.
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Michalski, Fernanda, und Carlos A. Peres. „Gamebird responses to anthropogenic forest fragmentation and degradation in a southern Amazonian landscape“. PeerJ 5 (07.06.2017): e3442. http://dx.doi.org/10.7717/peerj.3442.
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Although large-bodied tropical forest birds are impacted by both habitat loss and fragmentation, their patterns of habitat occupancy will also depend on the degree of forest habitat disturbance, which may interact synergistically or additively with fragmentation effects. Here, we examine the effects of forest patch and landscape metrics, and levels of forest disturbance on the patterns of persistence of six gamebird taxa in the southern Brazilian Amazon. We use both interview data conducted with long-term residents and/or landowners from 129 remnant forest patches and 15 continuous forest sites and line-transect census data from a subset of 21 forest patches and two continuous forests. Forest patch area was the strongest predictor of species persistence, explaining as much as 46% of the overall variation in gamebird species richness. Logistic regression models showed that anthropogenic disturbance—including surface wildfires, selective logging and hunting pressure—had a variety of effects on species persistence. Most large-bodied gamebird species were sensitive to forest fragmentation, occupying primarily large, high-quality forest patches in higher abundances, and were typically absent from patches <100 ha. Our findings highlight the importance of large (>10,000 ha), relatively undisturbed forest patches to both maximize persistence and maintain baseline abundances of large neotropical forest birds.
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Abrams, Marc D., Carolyn A. Copenheaver, Bryan A. Black und Saskia van de Gevel. „Dendroecology and climatic impacts for a relict, old-growth, bog forest in the Ridge and Valley Province of central Pennsylvania, U.S.A.“ Canadian Journal of Botany 79, Nr. 1 (01.01.2001): 58–69. http://dx.doi.org/10.1139/b00-145.
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We report on the 440-year dendrochronological history of a relict, bog forest in the Ridge and Valley Province of central Pennsylvania that contains extreme southern, disjunct populations of Picea mariana (Mill.) BSP and Abies balsamea (L.) Mill. The forest is dominated by Tsuga canadensis (L.) Carr. (49% relative importance value), Picea mariana (16%), and Acer rubrum L. (15%). The few remaining Abies balsamea trees are in a advanced state of decline. Many Nyssa sylvatica Marsh. and T. canadensis trees recruited from 1560 and 1700, respectively, until 1890. However, the majority of the other tree species recruited during a 40-year period following selective logging of the forest in the 1890s and fires in about 1900 and 1914. We found a scarcity of tree saplings and no evidence of recruitment into the tree-size class for any species after 1950. The master tree-ring chronology for both N. sylvatica and T. canadensis exhibits a marked increase after the 1890s logging and a decrease after a 1900 fire. In addition, a large number of releases in individual tree chronologies occurred over the last 400 years, indicating the frequent occurrence of small-scale disturbances. Tree-ring growth during the 20th century was reduced by droughts and cool temperatures in the 1920s and in the early to middle 1960s. Abies balsamea cores exhibit a marked growth decline in 1986. Tsuga canadensis growth was very low between 1970 and 1998, despite a generally warm and wet climate during that time. Picea mariana had a dramatic increase in growth during very warm and wet climate between 1995 and 1998. Most Abies balsamea trees have reached their pathological age of 50-85 years and have active Armillaria root rot, insect infestations, and very poorly developed crowns. These symptoms or severe growth declines are not present in Picea mariana. It appears that the 10 000 year history of Abies balsamea presence at Bear Meadows will end soon, with no opportunity to reestablish itself because of the lack of a local seed source. The results of this study suggest that relict tree populations in the eastern United States may be particularly sensitive to direct and indirect anthropogenic impacts and climatic variations, and represent important benchmarks for comparisons with future studies.Key words: tree rings, disturbance, climate, global change, central Pennsylvania.
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Las-Casas, Flor Maria Guedes, Iolanda Maria Silva da Pereira, Lilia D’ark Nunes dos Santos und Luciano Nicolás Naka. „The avifauna of the Catimbau National Park, an important protected area in the Brazilian semiarid“. Revista Brasileira de Ornitologia 27, Nr. 2 (Juni 2019): 79–93. http://dx.doi.org/10.1007/bf03544452.
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AbstractThe Catimbau National Park is a protected area, located within the Caatinga Dry Forest, in the central region of the Brazilian state of Pernambuco. This protected area encompasses ~60,000 ha of an exceptional diversity of habitats, resulting in a high avian diversity, including several rare and endemic species. The park is considered an area of high biological importance and of conservation priority. Despite its relevance for conservation, human degradation due to chronic anthropogenic disturbances (hunting, birds trapping, selective logging, and livestock grazing) has modified the park’s natural environments. In 2014, we initiated avian inventories within the park, as part of a long-term ecological research (LTER). Although the avifauna of the park has been described before, our systematic surveys allowed us to have a better understating of the park’s avifauna and resulted in several additions to the species list. Here, we update and reevaluate the park’s avifauna, discuss the presence of resident and migratory species, and include comments on endemic and rare species that occur within the park’s boundaries. We sampled the avifauna through systematic surveys (point counts) and opportunistic observations between 2014 and 2017, including both dry and rainy seasons. We recorded a total of 192 species, including 25 species new to the park’s list. During our point counts, we detected 117 species in the dry season, whereas 34 were recorded exclusively during the rainy season. Nearly 10% of the park’s avifauna (19 species) is represented by migratory species, such as Elaenia chilensis and Turdus amaurochalinus. Catimbau National Park is important for the conservation of the Caatinga avifauna, since it harbors endemic, range-restricted, migratory, and globally threatened species. Therefore, we emphasize that environmental education and ecological restoration projects, allied to enforcing environmental laws are urgent for the maintenance of biodiversity and ecosystem services in the Catimbau National Park.
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Shimizu, Katsuto, Raul Ponce-Hernandez, Oumer S. Ahmed, Tetsuji Ota, Zar Chi Win, Nobuya Mizoue und Shigejiro Yoshida. „Using Landsat time series imagery to detect forest disturbance in selectively logged tropical forests in Myanmar“. Canadian Journal of Forest Research 47, Nr. 3 (März 2017): 289–96. http://dx.doi.org/10.1139/cjfr-2016-0244.
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Detecting forest disturbances is an important task in formulating mitigation strategies for deforestation and forest degradation in the tropics. Our study investigated the use of Landsat time series imagery combined with a trajectory-based analysis for detecting forest disturbances resulting exclusively from selective logging in Myanmar. Selective logging was the only forest disturbance and degradation indicator used in this study as a causative force, and the results showed that the overall accuracy for forest disturbance detection based on selective logging was 83.0% in the study area. The areas affected by selective logging and other factors accounted for 4.7% and 5.4%, respectively, of the study area from 2000 to 2014. The detected disturbance areas were underestimated according to error assessments; however, a significant correlation between areas of disturbance and numbers of harvested trees during the logging year was observed, indicating the utility of a trajectory-based, annual Landsat imagery time series analysis for selective logging detection in the tropics. A major constraint of this study was the lack of available data for disturbances other than selective logging. Further studies should focus on identifying other types of disturbances and their impacts on future forest conditions.
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Dekelaita, Daniella, Paul Krausman und Shane Mahoney. „Estimated effects of clear-cuts and burns associated with habitat use by female Newfoundland Caribou (<i>Rangifer tarandus</i>)“. Canadian Field-Naturalist 136, Nr. 4 (21.06.2023): 316–32. http://dx.doi.org/10.22621/cfn.v136i4.2767.
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The decline of Caribou (Rangifer tarandus) is mainly attributed to anthropogenic disturbance from resource development (i.e., logging, oil and gas extraction), which causes habitat loss and increased predation risk. Natural landscape disturbance, particularly from fire, can have similar effects, and cumulative effects from disturbance have been associated with lower neonate recruitment. Our objective was to evaluate the potential effects of land cover types on resource selection by females, with an emphasis on clear-cuts and fire, during the calving season (May–June) in three neighbouring herds (Middle Ridge, Gaff Topsails, and Pot Hill) on insular Newfoundland, Canada, and compare results with pre-existing information on calf recruitment. We applied a resource selection framework to analyze location data collected from global positioning system collars between 2007–2010 and estimate relative probability of use for different cover types. Recruitment was lowest in Pot Hill, where ≤10-year old clear-cuts were favoured, whereas recruitment was highest in Middle Ridge and Gaff Topsails, where females favoured burns, suggesting that burns could be more beneficial to Caribou fitness. Further investigation will be needed to more closely examine how anthropogenic versus natural disturbance affects Caribou fitness in Newfoundland and improve our understanding of important habitat for calving females.
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Hunt, Len M., und Wolfgang Haider. „Aesthetic Impacts of Disturbances on Selected Boreal Forested Shorelines“. Forest Science 50, Nr. 5 (01.10.2004): 729–38. http://dx.doi.org/10.1093/forestscience/50.5.729.
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Abstract This article investigates the aesthetic impacts of anthropogenic and fire disturbances on forested shorelines for most coniferous forest types of the boreal forest. The novel use of the psychophysical landscape-perception approach to near-vista-view shoreline settings makes this application unique. Evaluations of aesthetic quality by laypeople show that severe fire and clearcut-logging disturbances make the forested shorelines much less attractive when compared to undisturbed sites. The analysis also provides a detailed examination of the relationships between undisturbed and logged sites by investigating the relationship between reserve width (i.e., the amount of land that separates the shoreline from logging activities) and aesthetic quality. A regression model of aesthetic evaluations demonstrates that aesthetics is positively related to undisturbed sites, to reserve width, and to the slope of the land. An interaction term of the reserve width and slope of the land is negative, which suggests that the reserve width necessary to mitigate the effects of logging on flat lands is smaller than the reserve width needed to mitigate logging on steeper lands. The model can also be used for predictive purposes such as estimating a reserve width that may be necessary to mitigate all visual effects of logging on shoreline sites. FOR. SCI. 50(5):729–738.
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Olander, Lydia P., Mercedes M. Bustamante, Gregory P. Asner, Everaldo Telles, Zayra Prado und Plínio B. Camargo. „Surface Soil Changes Following Selective Logging in an Eastern Amazon Forest“. Earth Interactions 9, Nr. 4 (01.04.2005): 1–19. http://dx.doi.org/10.1175/ei135.1.
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Abstract In the Brazilian Amazon, selective logging is second only to forest conversion in its extent. Conversion to pasture or agriculture tends to reduce soil nutrients and site productivity over time unless fertilizers are added. Logging removes nutrients in bole wood, enough that repeated logging could deplete essential nutrients over time. After a single logging event, nutrient losses are likely to be too small to observe in the large soil nutrient pools, but disturbances associated with logging also alter soil properties. Selective logging, particularly reduced-impact logging, results in consistent patterns of disturbance that may be associated with particular changes in soil properties. Soil bulk density, pH, carbon (C), nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), iron (Fe), aluminum (Al), δ13C, δ15N, and P fractionations were measured on the soils of four different types of logging-related disturbances: roads, decks, skids, and treefall gaps. Litter biomass and percent bare ground were also determined in these areas. To evaluate the importance of fresh foliage inputs from downed tree crowns in treefall gaps, foliar nutrients for mature forest trees were also determined and compared to that of fresh litterfall. The immediate impacts of logging on soil properties and how these might link to the longer-term estimated nutrient losses and the observed changes in soils were studied. In the most disturbed areas, roads and decks, the authors found litter biomass removed and reduced soil C, N, P, particularly organic P, and δ13C. Soils were compacted and often experienced reducing conditions in the deck areas, resulting in higher pH, Ca, and Mg. No increases in soil nutrients were observed in the treefall gaps despite the flush of nutrient-rich fresh foliage in the tree crown that is left behind after the bole wood is removed. Observed nutrient losses are most likely caused by displacement of the litter layer. Increases in soil pH, Ca, and Mg occur in areas with reducing conditions (decks and roads) and may result from Fe reduction, freeing exchange sites that can then retain these cations. Calculations suggest that nutrient inputs from crown foliage in treefall gaps are probably too small to detect against the background level of nutrients in the top soils. The logging disturbances with the greatest spatial extent, skids and gaps, have the smallest immediate effect on soil nutrients, while those with the smallest spatial extent, roads and decks, have the largest impact. The changes observed 3–6 months after logging were similar to those measured 16 yr after logging, suggesting some interesting linkages between the mechanisms causing the immediate change and those maintaining these changes over time. The direct impacts on soil properties appear less important than the loss of nutrients in bole wood in determining the sustainability of selective logging. Medium-to-low intensity selective logging with a sufficiently long cutting cycle may be sustainable in these forests.
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Lima, Thaís Almeida, René Beuchle, Andreas Langner, Rosana Cristina Grecchi, Verena C. Griess und Frédéric Achard. „Comparing Sentinel-2 MSI and Landsat 8 OLI Imagery for Monitoring Selective Logging in the Brazilian Amazon“. Remote Sensing 11, Nr. 8 (22.04.2019): 961. http://dx.doi.org/10.3390/rs11080961.
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Imagery from medium resolution satellites, such as Landsat, have long been used to map forest disturbances in the tropics. However, the Landsat spatial resolution (30 m) has often been considered too coarse for reliably mapping small-scale selective logging. Imagery from the recently launched Sentinel-2 sensor, with a resampled 10 m spatial resolution, may improve the detection of forest disturbances. This study compared the performance of Landsat 8 and Sentinel-2 data for the detection of selective logging in an area located in the Brazilian Amazon. Logging impacts in seven areas, which had governmental authorization for harvesting timber, were mapped by calculating the difference of a self-referenced normalized burn ratio (ΔrNBR) index over corresponding time periods (2016–2017) for imagery of both satellite sensors. A robust reference dataset was built using both high- and very-high-resolution imagery. It was used to define optimum ΔrNBR thresholds for forest disturbance maps, via a bootstrapping procedure, and for estimating accuracies and areas. A further assessment of our approach was also performed in three unlogged areas. Additionally, field data regarding logging infrastructure were collected in the seven study sites where logging occurred. Both satellites showed the same performance in terms of accuracy, with area-adjusted overall accuracies of 96.7% and 95.7% for Sentinel-2 and Landsat 8, respectively. However, Landsat 8 mapped 36.9% more area of selective logging compared to Sentinel-2 data. Logging infrastructure was better detected from Sentinel-2 (43.2%) than Landsat 8 (35.5%) data, confirming its potential for mapping small-scale logging. We assessed the impacted area by selective logging with a regular 300 m × 300 m grid over the pixel-based results, leading to 1143 ha and 1197 ha of disturbed forest on Sentinel-2 and Landsat 8 data, respectively. No substantial differences in terms of accuracy were found by adding three unlogged areas to the original seven study sites.
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Kishchuk, B. E., E. Thiffault, M. Lorente, S. Quideau, T. Keddy und D. Sidders. „Decadal soil and stand response to fire, harvest, and salvage-logging disturbances in the western boreal mixedwood forest of Alberta, Canada“. Canadian Journal of Forest Research 45, Nr. 2 (Februar 2015): 141–52. http://dx.doi.org/10.1139/cjfr-2014-0148.
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Empirical knowledge of long-term ecosystem response to single and compound disturbances is essential for predicting disturbance effects and identifying management practices to maintain productive capacity of managed and restored landscapes. We report on soil, foliar nutrition, and regeneration growth response to wildfire, clearcut harvesting, and postfire salvage logging, as well as undisturbed control stands within the first year following disturbance and 10–11 years after disturbance in trembling aspen – white spruce mixedwood forests near Lesser Slave Lake, north-central Alberta, Canada. The compound disturbance of salvage logging resulted in greater long-term impacts on forest floor properties than either wildfire or harvesting alone. Changes in forest floor properties such as carbon and nitrogen pools and cation exchange capacity under salvage logging have persisted for 10 years and exhibit a different recovery trajectory than fire or harvesting. Forest floor properties under harvesting, including depth, carbon content, pH, extractable ammonium, and extractable sulphur, were not different from the control condition 10 years after harvest. Effects on soil and foliar nutrition were not reflected in productivity (height and diameter) of regenerating vegetation. Our results show differences between short- and long-term responses to disturbance, among single natural and anthropogenic disturbances, and among single and compound disturbances.
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Bednařík, J., V. Čada und K. Matějka. „Forest succession after a major anthropogenic disturbance: a case study of the Jewish Forest in the Bohemian Forest, Czech Republic“. Journal of Forest Science 60, No. 8 (01.09.2014): 336–48. http://dx.doi.org/10.17221/57/2014-jfs.
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The knowledge of forest development after disturbances, particularly anthropogenic disturbances, is of major importance for forest management. Many areas of mountain forests in Europe have been affected by human activities such as felling and livestock grazing in the past and then left for natural succession. Those forests provide several ecosystem services (e.g. soil or avalanche protection) and therefore it is vital to know their developmental processes. The Norway spruce forest stand in the area of Medvědí Mt. (Šumava National Park, Czech Republic), known as the Jewish Forest, is considered an example of succession after anthropogenic disturbances. This study aimed to: <br /> (1) analyse the history of disturbances which affected the locality, (2) describe the subsequent process of forest succession which led to the development of the present forest formation. We conducted a dendrochronological analysis and a spatial analysis. The main cohort was established after a period of disturbances in the first half of the 20<sup>th</sup> century. Both natural (windstorm) and anthropogenic (logging and livestock grazing) disturbances coincided during this period. Regeneration of low density was restricted to a short period after the disturbance and was likely dependent on the occurrence of proper microsites. Later, regeneration was probably obstructed by lack of convenient microsites and high competition of the herb layer. Nowadays, new regeneration emerges together with proper microsite at decaying wood and near mature trees. We conclude that anthropogenic disturbances can limit the density and heterogeneity of regeneration, which leads to the establishment of sparse stand. This structure can persist for decades before proper microsites accumulate and enable regeneration.
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Shvetsov, Evgeny G., Elena A. Kukavskaya, Tatiana A. Shestakova, Jocelyne Laflamme und Brendan M. Rogers. „Increasing fire and logging disturbances in Siberian boreal forests: a case study of the Angara region“. Environmental Research Letters 16, Nr. 11 (22.10.2021): 115007. http://dx.doi.org/10.1088/1748-9326/ac2e37.
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Abstract Forest disturbances are a critical environmental issue globally and within the boreal biome, yet detailed attribution and trends in disturbances are lacking for many Siberian regions. The Angara region located in the southern taiga of Central Siberia has experienced significant disturbances during the past several decades and is a hotspot of change in Eurasia. Here we estimated fire and logging disturbances using MODIS and Landsat data for the period 2002–2020 across the Angara region and analyzed the resulting trends. Average annual burned and logged area was about 220 and 31 thousand ha or 2 and 0.3% of the study area, respectively. In total, about 4.1 million ha (38% of the region) and 0.6 million ha (6% of the region) were disturbed by fires and logging, respectively. Spatial analysis showed that almost 50% of fires were ignited within 2 km of anthropogenic features such as settlements, roads and logged areas. Almost 5% of the Angara region was burned two or more times during the 19 years of observations. Improved and strictly-enforced conservation and management policies are required to halt continued forest degradation in the Angara region and similarly-affected boreal forests in Siberia.
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Saad, Siti Nor Maizah, Wan Shafrina Wan Mohd Jaafar, Hamdan Omar, Khairul Nizam Abdul Maulud, Aisyah Marliza Muhmad Kamarulzaman, Esmaeel Adrah, Norzalyta Mohd Ghazali und Midhun Mohan. „Modeling Carbon Emissions of Post-Selective Logging in the Production Forests of Ulu Jelai, Pahang, Malaysia“. Remote Sensing 15, Nr. 4 (12.02.2023): 1016. http://dx.doi.org/10.3390/rs15041016.
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Harvested timber and constructed infrastructure over the logging area leave massive damage that contributes to the emission of anthropogenic gases into the atmosphere. Carbon emissions from tropical deforestation and forest degradation are the second largest source of anthropogenic emissions of greenhouse gases. Even though the emissions vary from region to region, a significant amount of carbon emissions comes mostly from timber harvesting, which is tightly linked to the selective logging intensity. This study intended to utilize a remote sensing approach to quantify carbon emissions from selective logging activities in Ulu Jelai Forest Reserve, Pahang, Malaysia. To quantify the emissions, the relevant variables from the logging’s impact were identified as a predictor in the model development and were listed as stump height, stump diameter, cross-sectional area, timber volume, logging gaps, road, skid trails, and incidental damage resulting from the logging process. The predictive performance of linear regression and machine learning models, namely support vector machine (SVM), random forest, and K-nearest neighbor, were examined to assess the carbon emission from this degraded forest. To test the different methods, a combination of ground inventory plots, unmanned aerial vehicles (UAV), and satellite imagery were analyzed, and the performance in terms of root mean square error (RMSE), bias, and coefficient of correlation (R2) were calculated. Among the four models tested, the machine learning model SVM provided the best accuracy with an RMSE of 21.10% and a bias of 0.23% with an adjusted R2 of 0.80. Meanwhile, the linear model performed second with an RMSE of 22.14%, a bias of 0.72%, and an adjusted R2 of 0.75. This study demonstrates the efficacy of remotely sensed data to facilitate the conventional methods of quantifying carbon emissions from selective logging and promoting advanced assessments that are more effective, especially in massive logging areas and various forest conditions. Findings from this research will be useful in assisting the relevant authorities in optimizing logging practices to sustain forest carbon sequestration for climate change mitigation.
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Oldfield, Callie, und Chris Peterson. „Aboveground Biomass and Carbon Accumulation 19 Years Post-Windthrow and Salvage Logging“. Forests 12, Nr. 2 (02.02.2021): 173. http://dx.doi.org/10.3390/f12020173.
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Natural disturbances shape forest ecosystem characteristics, including carbon storage and structure. Often, natural disturbances are compounded with anthropogenic disturbances, which may alter the trajectory of forest carbon stock recovery. Heterogeneous levels of disturbance severity in compound disturbance events add an additional layer of complexity. This paper examines the effect of a moderate-severity wind disturbance and subsequent salvage logging on forest biomass and carbon stock recovery over 19 years. We investigate the recovery of aboveground tree biomass following a wind disturbance and salvage logging and examine the role of wind disturbance severity on biomass accumulation rates. We use pre-disturbance, 3 years post-wind disturbance and 19 years post-wind disturbance measurements of tree biomass across two adjacent sites at Natchez Trace State Forest for Site A and Site B in east central Tennessee. We found no significant difference in the carbon storage at Site A (pre = 92 MgC/ha; 19 years post-disturbance = 83 MgC/ha) or Site B (pre = 66 MgC/ha; 19 years post-disturbance = 67) when comparing the pre-disturbance level of aboveground tree carbon storage with the 19-years post-disturbance levels. Furthermore, we found no evidence that salvage logging reduced the rate of live tree carbon accumulation. The corresponding rates of mean annual carbon accumulation (MgC/ha) are as follows: Site A Unsalvaged (1.07), Site A Salvaged (1.25) and Site B Salvaged (2.02). Contrary to our prediction, greater wind damage severity was weakly associated with higher rates of biomass accumulation (R2 = 0.17). While we found no negative effect of salvage logging on the aboveground tree carbon accumulation rate, salvage logging alters other carbon pools, including coarse woody debris. Salvage logging did not reduce the rate of carbon stock recovery, and a higher wind disturbance severity was associated with a greater rate of carbon stock recovery.
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Théodore, Etien Dibié, Vroh Bi Tra Aimé, Adou Yao Constant Yves und N’Guessan Kouakou Edouard. „Diversité Des Espèces Herbacées Et Lianescentes De La Forêt Classée Du Haut-Sassandra (Centre-Ouest, Côte d’Ivoire) Après Plusieurs Années D’exploitation Forestière“. European Scientific Journal, ESJ 14, Nr. 18 (30.06.2018): 247. http://dx.doi.org/10.19044/esj.2018.v14n18p247.
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Natural and anthropogenic disturbances affect forest integrity and floristic composition. The resulting secondary habitats is characterised by liana and herb species which modified the forest physiognomy. To elucidate the floristic characteristics of these secondary forests, the present study was carried out after logging operations in the the Haut-Sassandra protected Forest. The inventory has been realised in 18 individual one ha in three level of logging operation. A total of 445 species have been identified. Floristics parameters vary according to the time after logging operation: from 255 in the south sector, 296 species in the center sector, 271 species in the north sector, 15 years after logging. The family diversity is between 56 and 62 with a predominance of Rubiaceae. Phytogeographic-types are characterized by Guinean-Congolese species (71,2 %), and species endemic to SavannahForest transition zone (14,6 %). The presence of herb and liana species which are pioneer and heliophile, could generate a micro climate favorable to the recovery of other forest plant species.
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Perry, Kayla, und Daniel Herms. „Dynamic Responses of Ground-Dwelling Invertebrate Communities to Disturbance in Forest Ecosystems“. Insects 10, Nr. 3 (26.02.2019): 61. http://dx.doi.org/10.3390/insects10030061.
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In forest ecosystems, natural and anthropogenic disturbances alter canopy structure, understory vegetation, amount of woody debris, and the properties of litter and soil layers. The magnitude of these environmental changes is context-dependent and determined by the properties of the disturbance, such as the frequency, intensity, duration, and extent. Therefore, disturbances can dynamically impact forest communities over time, including populations of ground-dwelling invertebrates that regulate key ecosystem processes. We propose conceptual models that describe the dynamic temporal effects of canopy gap formation and coarse woody debris accumulation following disturbances caused by invasive insects, wind, and salvage logging, and their impacts on ground-dwelling invertebrate communities. Within this framework, predictions are generated, literature on ground-dwelling invertebrate communities is synthesized, and pertinent knowledge gaps identified.
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SLAGHT, JONATHAN C., und SERGEI G. SURMACH. „Blakiston’s Fish-owl Bubo blakistoni and logging: Applying resource selection information to endangered species conservation in Russia“. Bird Conservation International 26, Nr. 2 (28.09.2015): 214–24. http://dx.doi.org/10.1017/s0959270915000076.
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SummaryBlakiston's Fish-owl Bubo blakistoni is classified as ‘Endangered’ by IUCN; this species is associated with riparian old-growth forests in north-east Asia, a landscape threatened by a variety of impacts (e.g. logging, agricultural development, human settlement). We examined a 20,213 km2 study area in Primorye, Russia, and assessed the ability of the protected area network to conserve Blakiston's Fish-owls by analysing resource selection of radio-marked individuals. Based on resource selection functions, we predicted that 60–65 Blakiston's fish-owl home ranges could occur within the study area. We found that the protected area network within our study area contained only 19% of optimal Blakiston's fish-owl habitat and contained only eight potential home ranges (five of these within a single protected area—Sikhote-Alin Biosphere Reserve). We also found that 43% of optimal Blakiston's Fish-owl habitat was within current logging leases; lands capable of supporting habitat equivalent to 24 home ranges. The remaining optimal habitat (38%) was on federal land and potentially contained 28–33 Blakiston's Fish-owl home ranges. The current protected area network, by itself, is not sufficient to conserve the species because relatively few home ranges are actually protected. Therefore, outside of protected areas, we recommend protecting specific locations within potential home ranges that likely contain suitable nest and foraging sites, maintaining integrity of riparian areas, modifying road construction methods, and closing old and unused logging roads to reduce anthropogenic disturbance to the owls and the landscape.
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Rondon, Xanic J., Graeme S. Cumming, Rosa E. Cossío und Jane Southworth. „The Effects of Selective Logging Behaviors on Forest Fragmentation and Recovery“. International Journal of Forestry Research 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/170974.
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To study the impacts of selective logging behaviors on a forest landscape, we developed an intermediate-scale spatial model to link cross-scale interactions of timber harvesting, a fine-scale human activity, with coarse-scale landscape impacts. We used the Lotka-Volterra predator-prey model with Holling’s functional response II to simulate selective logging, coupled with a cellular automaton model to simulate logger mobility and forest fragmentation. Three logging scenarios were simulated, each varying in timber harvesting preference and logger mobility. We quantified forest resilience by evaluating (1) the spatial patterns of forest fragmentation, (2) the time until the system crossed a threshold into a deforested state, and (3) recovery time. Our simulations showed that logging behaviors involving decisions made about harvesting timber and mobility can lead to different spatial patterns of forest fragmentation. They can, together with forest management practices, significantly delay or accelerate the transition of a forest landscape to a deforested state and its return to a recovered state. Intermediate-scale models emerge as useful tools for understanding cross-scale interactions between human activities and the spatial patterns that are created by anthropogenic land use.
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Royo, Alejandro A., Chris J. Peterson, John S. Stanovick und Walter P. Carson. „Evaluating the ecological impacts of salvage logging: can natural and anthropogenic disturbances promote coexistence?“ Ecology 97, Nr. 6 (Juni 2016): 1566–82. http://dx.doi.org/10.1890/15-1093.1.
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SHCHUR, ALEXANDER, EUGENIA BRAGINA, ANIKA SIEBER, ANNA M. PIDGEON und VOLKER C. RADELOFF. „Monitoring selective logging with Landsat satellite imagery reveals that protected forests in Western Siberia experience greater harvest than non-protected forests“. Environmental Conservation 44, Nr. 2 (24.01.2017): 191–99. http://dx.doi.org/10.1017/s0376892916000576.
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SUMMARYWhen timber harvesting is an important source of local income and forest resources are declining, even forests that are designated as protected areas may become vulnerable. Therefore, regular monitoring of forest disturbance is necessary to enforce the protection of forest ecosystems. However, mapping forest disturbance with satellite imagery can be complicated if the majority of the harvesting is selective logging and not clearcuts. Our goal was to map both selective logging and clearcuts within and outside of protected areas in Western Siberia, a region with a highly developed timber industry. Combining summer and winter imagery allowed us to accurately estimate not only clearcuts, but also selective logging. Winter Landsat images substantially improved our classification and resulted in a highly accurate forest disturbance map (97.5% overall accuracy and 86% user accuracy for the rarest class, clearcuts). Selective logging and stripcuts were the dominant disturbance types, accounting for 96.3% of all forest disturbances, versus 3.7% for clearcuts. The total annual forest disturbance rate (i.e. disturbance rate for clearcuts, stripcuts and selective logging together) was 0.53%, but total forest disturbance within protected areas was greater than in non-protected forest (0.66% versus 0.50%, respectively), and so was the annual rate of selective logging (i.e. without clearcuts, 0.37% versus 0.25%, respectively). Our results highlight that monitoring only clearcuts without assessing selective logging might result in significant underestimation of forest disturbance. Also, when timber harvesting is important for the local economy and when protected areas have valuable timber resources that have already been depleted elsewhere, then additional protection may be necessary in order to maintain natural forests within protected areas. We suggest that this is the situation in our study area in Western Siberia right now and is likely the situation in many other parts of the globe as well.
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Garcia, M. A. R., und J. A. Principe. „ASSESSMENT OF FOREST DISTURBANCES USING REMOTE SENSING: CASE OF KALIWA RIVER FOREST RESERVE (KRFR), PHILIPPINES“. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-4/W8-2023 (25.04.2024): 273–78. http://dx.doi.org/10.5194/isprs-archives-xlviii-4-w8-2023-273-2024.
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Abstract. The Kaliwa River Forest Reserve (KRFR) is located in the southwestern part of the Sierra Madre Mountain Range, Philippines. KRFR is one of the most important forest reserves in the country that is adjacent to urban areas and is very much affected by various forest disturbances. Forest disturbances can be caused by either anthropogenic or natural phenomena (e.g., typhoons, drought, and pathogen outbreaks) and may have negative effects on the forest structure and function. The study used the Normalized Difference Moisture Index (NDMI) in detecting forest disturbances for the period of 2010, 2015, and 2020. Results showed that the deforestation rate has significantly decreased from 6.22% in 2010 to 3.40% in 2020. The National Greening Program (NGP) and intensified forest protection activities of the Department of Environment and Natural Resources (DENR) may have contributed to the observed decreasing trend in deforestation rate. However, forest disturbance in the closed and open forest areas of KRFR gradually increased from 0.11% to 0.40%. Based on the accuracy assessment, the NDMI performed well in determining forest disturbances with mean values of 0.91 and 0.93 for completeness and correctness, respectively. The main contributor to forest disturbances in KRFR was mainly anthropogenic factors such as kaingin, illegal logging, urban sprawl, and upland farming. Outputs of this study can aid in the formulation of policies for better forest resource management, rehabilitation, and protection in the protected area.
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Vaze, J., Y. Q. Zhang und L. Zhang. „Water dynamics under changing land cover“. Proceedings of the International Association of Hydrological Sciences 371 (12.06.2015): 215–21. http://dx.doi.org/10.5194/piahs-371-215-2015.
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Abstract. Most of the forested headwater catchments are an important source of water supply in many parts of the world. A prime example is southeast Australia where forests supply major river systems and towns and cities with water. It is critical for an informed and adaptive water resource management to understand changes in streamflow caused by vegetation changes in these headwater forest catchments. Natural disturbances such as bushfires and anthropogenic activities like forestation, deforestation, or logging alter vegetation, evapotranspiration and soil water status, and may affect water supplies. Although catchment water yield is mainly controlled by climatic conditions, but it is also strongly influenced by land cover changes because of natural disturbances and anthropogenic activities. It is necessary to accurately estimate streamflow in water supply catchments subjected to dramatic land surface changes. This paper summarises the methods commonly used to investigate the impacts of land cover change on water resources, and provides some examples of impacts of afforestation/deforestation and bushfire on water resources in two southeast Australian catchments.
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Khai, Tual Cin, Nobuya Mizoue und Tetsuji Ota. „Post-Harvest Stand Dynamics over Five Years in Selectively Logged Production Forests in Bago, Myanmar“. Forests 11, Nr. 2 (10.02.2020): 195. http://dx.doi.org/10.3390/f11020195.
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Understanding the stand dynamics of tropical production forests is essential for determining the sustainability of a polycyclic selective logging system, but limited related studies have addressed the impacts of illegal logging over time. Myanmar faces the extensive degradation of traditional production forests with a 160-year logging history, but the cause of this degradation and how to balance legal and/or illegal disturbances with recovery in over-logged forests remain unclear. The present study investigated stand structural changes over 5 years after official legal logging operations using two 1-ha (100 × 100 m) sample plots. For 5 years after logging, the volume of trees with a diameter at breast height (DBH) ≥ 20 cm decreased by 46.0% from 121 to 65.1 m3 ha−1, with a significant loss of the first- and second-grade species group (Tectona grandis Linn. f. and Xylia xylocarpa (Roxb.) Taub.) from 48.3 to 6.8 m3 ha−1. The total tree loss owing to official logging operations, mainly targeting the second- and fourth-grade species group, was 29.3 m3 ha−1. A similar level of total tree loss (28.0 m3 ha−1) was attributed to illegal logging that targeted the first- and second-grade species group. The mean annual recruitment rate of 3.1% was larger than the reported values for tropical forests, but there were no and only 1.5 trees ha−1 recruitments s for T. grandis and X. xylocarpa, respectively. The mean annual mortality rate of 2.5% was within the values reported in the related literature, and the volume loss from the mortality was relatively similar to the gain from the increment of living trees for all species groups. We concluded that the effects of illegal disturbances for 5 years post-harvest were equivalent to those of legal disturbances and larger than those of natural change, and are a major cause of the substantial reduction in stocking levels, especially for commercial species.
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De Marzo, Teresa, Nestor Ignacio Gasparri, Eric F. Lambin und Tobias Kuemmerle. „Agents of Forest Disturbance in the Argentine Dry Chaco“. Remote Sensing 14, Nr. 7 (06.04.2022): 1758. http://dx.doi.org/10.3390/rs14071758.
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Forest degradation in the tropics is a widespread, yet poorly understood phenomenon. This is particularly true for tropical and subtropical dry forests, where a variety of disturbances, both natural and anthropogenic, affect forest canopies. Addressing forest degradation thus requires a spatially-explicit understanding of the causes of disturbances. Here, we apply an approach for attributing agents of forest disturbance across large areas of tropical dry forests, based on the Landsat image time series. Focusing on the 489,000 km2 Argentine Dry Chaco, we derived metrics on the spectral characteristics and shape of disturbance patches. We then used these metrics in a random forests classification framework to estimate the area of logging, fire, partial clearing, riparian changes and drought. Our results highlight that partial clearing was the most widespread type of forest disturbance from 1990–to 2017, extending over 5520 km2 (±407 km2), followed by fire (4562 ± 388 km2) and logging (3891 ± 341 km2). Our analyses also reveal marked trends over time, with partial clearing generally becoming more prevalent, whereas fires declined. Comparing the spatial patterns of different disturbance types against accessibility indicators showed that fire and logging prevalence was higher closer to fields, while smallholder homesteads were associated with less burning. Roads were, surprisingly, not associated with clear trends in disturbance prevalence. To our knowledge, this is the first attribution of disturbance agents in tropical dry forests based on satellite-based indicators. While our study reveals remaining uncertainties in this attribution process, our framework has considerable potential for monitoring tropical dry forest disturbances at scale. Tropical dry forests in South America, Africa and Southeast Asia are some of the fastest disappearing ecosystems on the planet, and more robust monitoring of forest degradation in these regions is urgently needed.
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Stoddart, Jaz, Danilo Roberti Alves de Almeida, Carlos Alberto Silva, Eric Bastos Görgens, Michael Keller und Ruben Valbuena. „A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits“. Remote Sensing 14, Nr. 4 (15.02.2022): 933. http://dx.doi.org/10.3390/rs14040933.
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Current LiDAR-based methods for detecting forest change use a host of statistically selected variables which typically lack a biological link with the characteristics of the ecosystem. Consensus of the literature indicates that many authors use LiDAR to derive ecosystem morphological traits (EMTs)—namely, vegetation height, vegetation cover, and vertical structural complexity—to identify small-scale changes in forest ecosystems. Here, we provide a conceptual, biological model for predicting forest aboveground biomass (AGB) change based on EMTs. We show that through use of a multitemporal dataset it is possible to not only identify losses caused by logging in the period between data collection but also identify regions of regrowth from prior logging using EMTs. This sensitivity to the change in forest dynamics was the criterion by which LiDAR metrics were selected as proxies for each EMT. For vegetation height, results showed that the top-of-canopy height derived from a canopy height model was more sensitive to logging than the average or high percentile of raw LiDAR height distributions. For vegetation cover metrics, lower height thresholds for fractional cover calculations were more sensitive to selective logging and the regeneration of understory. For describing the structural complexity in the vertical profile, the Gini coefficient was found to be superior to foliage height diversity for detecting the dynamics occurring over the years after logging. The subsequent conceptual model for AGB estimation obtained a level of accuracy which was comparable to a model that was statistically optimised for that same area. We argue that a widespread adoption of an EMT-based conceptual approach would improve the transferability and comparability of LiDAR models for AGB worldwide.
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Wang, Cuizhen, Jiaguo Qi und Mark Cochrane. „Assessment of Tropical Forest Degradation with Canopy Fractional Cover from Landsat ETM+ and IKONOS Imagery“. Earth Interactions 9, Nr. 22 (01.10.2005): 1–18. http://dx.doi.org/10.1175/ei133.1.
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Abstract Tropical forests are being subjected to a wide array of disturbances in addition to outright deforestation. Selective logging is one of the most common disturbances ongoing in the Amazon, which results in significant changes in forest structure and canopy integrity. Assessing forest canopy fractional cover (fc) is one way of measuring forest degradation caused by selective logging. In this study we applied a linear mixture model to a vegetation index domain to map canopy fractional cover in tropical forests in the Amazonian state of Mato Grosso, Brazil. The modified soil adjusted vegetation index (MSAVI) was selected as the optimal vegetation index in the model because it is most linearly related to green canopy abundance up to leaf area index = 4.0. In the canopy fc map derived from the Landsat Enhanced Thematic Mapper Plus (ETM+) image, the fc distribution ranged from 0 to 0.4 in clear-cut areas, higher than 0.8 in undisturbed forests, and a wider range of 0.3–1.0 in degraded forests. The fc map was validated with the 1-m panchromatic sharpened IKONOS image. In the logged forests the ETM+ estimated fc values were clustered along the 1:1 line in the scatterplot with the IKONOS estimated fc and had a squared correlation coefficient (R2) of 0.8.
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Venanzi, Rachele, Loredana Barbona, Francesco Latterini und Rodolfo Picchio. „Disturbances to the Ground and to the Stand in Beech Forests Due to Thinning Treatments Performed by Different Levels of Mechanization“. Environmental Sciences Proceedings 3, Nr. 1 (13.11.2020): 58. http://dx.doi.org/10.3390/iecf2020-08090.
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The aim of this work was to assess the possible impacts on the forest soil and stand due to silvicultural treatment and forest operations in a beech high forest. Even aged beech forests (Fagus sylvatica L.) in the Municipality of Cappadocia (L’Aquila) and in the Municipality of Vallepietra (Roma) were analyzed. The analysis of the soil and stand were performed in order to assess the effects attributable to applied silviculture and forest logging. Two different logging methodologies (in particular for the extraction) were applied: mules were used in the areas with greater slopes and with obstacles, while for the areas with better accessibility, mechanical means were used, in this case tractors. In detail, the main objective was to assess the disturbance on the ground and on the stand, generated by the two different levels of mechanization. In addition, it was also interesting to understand the possible effect on the soil and specifically on the partial uncovering where part of the tree canopy was removed. Only through an accurate cross-analysis of the studied parameters and indices could the anthropogenic impacts on the soil and stand due to forest operations be highlighted according to the different logging methodologies applied. The main results showed that the disturbances caused to the soil and stand were essentially caused in the bunching and extraction operations. The importance of avoiding or limiting the continuous passage of vehicles and animals on forest soil clearly emerges, especially in conditions of high soil moisture. It is also important to use correct technologies that are adequate for the specific environmental characteristics and the work plan. Finally, it can be said that there was no difference in the disturbance caused by the two logging methods when compared. Substantial differences in terms of improvement can be defined when comparing the findings of this study with other research studies. This can be done by applying a different type of mechanization with a different logging system.
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Gridneva, Vera V., und Basil N. Yakimov. „Transformation of hemiboreal ornithocenoses in modern forest management“. Ecosystem Transformation 5, Nr. 1 (2022): 19–26. http://dx.doi.org/10.23859/estr-211107.
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The ornithocenoses of a sequence of forestry succession stages are studied in different types of hemiboreal forests of the Russian Plain, and the species of birds that determine each of the recognized stages is given. Statistical analysis showed that anthropogenic disturbances and natural succession processes played a significant role in the transformation of ornithocenoses, against a background of less influence from forestry activities (conifer plantations and their maintenance). Dispersion decomposition showed a high proportion of the combined effect of exogenous and endogenous factors, as well as their equivalent contribution to the formation of ornithocenoses, was demonstrated. Various types of logging are shown to facilitate shifts of natural succession of forest ornithocenoses to anthropodynamic successions characterized by specific subclimax stages.
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McGrath, Sarah J., Jing Liu, Ben C. Stevenson und Alison M. Behie. „Density and population size estimates of the endangered northern yellow-cheeked crested gibbon Nomascus annamensis in selectively logged Veun Sai-Siem Pang National Park in Cambodia using acoustic spatial capture-recapture methods“. PLOS ONE 18, Nr. 11 (27.11.2023): e0292386. http://dx.doi.org/10.1371/journal.pone.0292386.
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Many gibbon species are threatened with extinction, including the endangered northern yellow-cheeked crested gibbon, Nomascus annamensis. Assessing gibbon populations and understanding how human disturbances and environmental factors impact these populations is vital for effective conservation planning. In 2010, auditory surveys revealed that Veun Sai-Siem Pang National Park (VSSP) in Cambodia contains one of the largest known N. annamensis populations in the world, with an estimated 456 (95% CI 421–490) gibbon groups. Illegal selective logging is common in the park, but the impact of continued logging on the gibbon population has not been investigated. To determine any change in the N. annamensis population since 2010, between January and April 2019 we conducted auditory surveys at 13 sites that were at least 4 km apart. We surveyed each site for three days, each day recording the gibbon calls heard over 3.25 hours from three listening posts located 500 m apart. At the same sites, we assessed the logging intensity using transects and ecological plots. Gibbon densities can be influenced by various environmental factors such as canopy height and forest type. Therefore, in addition to investigating the relationship between the density of N. annamensis groups and logging, we included five additional environmental variables in our acoustic spatial capture-recapture models. Our best fit model with the lowest AIC value included canopy height, forest type, distance to villages, and logging. We estimate that there are 389 (95% CI 284–542) N. annamensis groups currently in VSSP. Selective logging is widespread in the park, primarily targeting four tree species. The estimated felling time of these logged trees, together with previous reports, indicate that the species most targeted in VSSP varies over time. To conserve the N. annamensis population in VSSP, it is crucial that action is taken to reduce illegal logging.
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Silveira, Juliana M., Jos Barlow, Rafael B. Andrade, Luiz A. M. Mestre, Sébastien Lacau und Mark A. Cochrane. „Responses of leaf-litter ant communities to tropical forest wildfires vary with season“. Journal of Tropical Ecology 28, Nr. 5 (29.08.2012): 515–18. http://dx.doi.org/10.1017/s026646741200051x.
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Fire is an important land-management tool in tropical forest landscapes. However, these fires sometimes escape into surrounding forests (Uhl & Buschbacker 1985), and are one of the most severe disturbances threatening tropical forest biodiversity (Barlowet al2006). These forest fires have become more frequent over the last decades due to the combined effect of selective logging, fragmentation and abnormal droughts that increase the flammability of forests, and agriculture expansion that brings the ignition sources (Aragão & Shimabukuro 2010).
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Tikhonova, Tatyana V. „Logging activities in the North: Assessing the impact on biodiversity conservation“. Север и рынок: формирование экономического порядка 26, Nr. 2/2023 (30.06.2023): 24–37. http://dx.doi.org/10.37614/2220-802x.2.2023.80.002.
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In the context of sustainable forestry, biodiversity conservation assessment is a necessary element in asset and service accounting. Logging is an important driver of economic growth in the northern regions of Russia. The past twenty years have seen changes in timber harvesting technologies and forest management principles, which has led to an increase in research interest in identifying ecosystem responses in terms of biodiversity conservation. This study aims to assess changes in biodiversity within the active forest management territory of the Komi Republic, encompassing ten municipal districts and 24 forestry areas. The objectives of the study include evaluating the impact of factors such as population density, road network, and intact area on biodiversity preservation. Statistical analysis methods were utilized to assess the biodiversity status, focusing on the number of rare species threatened by logging. The analysis studied changes in species abundance, territorial distribution across forestry areas, and changes in their conservation status. Using statistical and factor analysis methods, the study identified the impact of forestry and anthropogenic factors on the conservation of species. The novelty of the research consists in identifying the stability degree of ecosystems by analyzing the state of large areas that have experienced long-term anthropogenic impacts on the Komi Republic territory. Most forests within the active forest management zone demonstrated favorable ecosystem conditions, with logging activities causing lichen disappearance and reduced fish numbers only in individual small areas. The anthropogenic impact had minimal influence on the number of rare species due to low population and road network density. Large areas of undisturbed forests contribute to the natural preservation of biodiversity, but their significant reduction in the southern area causes a threat to the existence of rare species. The greatest impact on the change in biodiversity on the territories affected by active forest management is caused by factors such as the level of territorial exploration, the preservation of undisturbed forests, and selective logging. The practical significance of this study lies in the potential application of the proposed algorithm by large Russian forest businesses when conducting their operations.
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Valverde-Barrantes, OJ, JA Hogan und OJ Rocha. „EFFECTS OF CANOPY OPENNESS ON SEEDLING SURVIVAL AND GROWTH AFTER SELECTIVE LOGGING IN A MONODOMINANT LOWLAND SWAMP FOREST IN COSTA RICA“. JOURNAL OF TROPICAL FOREST SCIENCE 34, Nr. 1 (26.01.2022): 34–47. http://dx.doi.org/10.26525/jtfs2022.34.1.34.
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The mechanism proposed to explain tree monodominance in tropical forests is that the dominant species forms a dense canopy and produces shade-tolerant seedlings, which together favor selfreplacement. Under this hypothesis, seedlings of monodominant species should have limited ability to respond to drastic increases in understory light, like those resulting from logging. Therefore, monodominant species should lose their seedling dominance after logging-induced canopy opening. To test this hypothesis, the current study measured seedling survival and growth of the monodominant species, Prioria copaifera, and its main competitor, Pentaclethra macroloba, in two forest stands that differ in logging history and in an unlogged stand in southeastern Costa Rica. Although, growth rates and survival of previously established seedlings were similar for both species across the three stands, seedling survival and growth decreased as light increased, with the effect being more pronounced for Prioria than for Pentaclethra. The study also investigated the ability of Prioria to respond to changing light environments by transplanting seedlings into logging-induced canopy gaps. Contrary to prediction, Prioria seedlings survived and grew better in gap centers than in gap edges or under a closed canopy. This result contrasts with established seedlings that cannot acclimate to changes in light conditions. Therefore, we conclude that continued Prioria dominance in selectively logged forests depends more on seedling production after canopy disturbance than on the established seedling present before disturbances.
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Abuzov, Aleksandr V., und Nikolay V. Kazakov. „Ecological consequences in forest stands subject to anthropogenic impact during logging and transport operations“. RUDN Journal of Ecology and Life Safety 28, Nr. 1 (15.12.2020): 7–18. http://dx.doi.org/10.22363/2313-2310-2020-28-1-7-18.
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The article presents the results of experimental studies reflecting the ecological reality of the consequences of the standard logging process, in which the destruction of the remaining forest stands takes place. The main environmental factors of anthropogenic impact on forest plantations, passed through selective felling using forestry equipment, are disclosed. The main regularities have been identified and formalized, allowing to quantify the damage caused to trees left on the cutting area. Statistical data of experimental observations of damage to forest stands are given, depending on the conditions of their growth. The obtained patterns are implemented in the Predic applic 1.0 software package, officially registered with Rospatent.
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Liu, Shufang, Zuoqiang Yuan, Arshad Ali, Anvar Sanaei, Zikun Mao, Fan Ding, Di Zheng et al. „Anthropogenic Disturbances Shape Soil Capillary and Saturated Water Retention Indirectly via Plant Functional Traits and Soil Organic Carbon in Temperate Forests“. Forests 12, Nr. 11 (18.11.2021): 1588. http://dx.doi.org/10.3390/f12111588.
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Soil’s water-physical properties support essential soil water retention functions for driving water distribution and availability, which is vital for plant growth and biogeochemical cycling. However, the question concerning how tree compositions and their interactions with other abiotic factors modulate soil’s water-physical properties in disturbed forests remains poorly understood. Based on observational data from nine permanent forest sites (18,747 trees and 210 plots) in the northeast of China, where forests once undergone three different levels of anthropogenic logging disturbance, we evaluated how multiple biotic (i.e., tree diversity and functional trait composition) and abiotic (soil texture and soil organic carbon) factors influence water-physical properties (i.e., in terms of soil capillary water retention (WC) and soil saturated water retention (WS)) in temperate forests. We found that the impacts of logging disturbance on soil water-physical properties were associated with improved tree diversity, acquisitive functional traits, and SOC. These associated attributes were also positively related to WC and WS, while there was no significant effect from soil texture. Moreover, disturbance indirectly affected soil water-physical properties mainly by functional traits and SOC, as acquisitive functional traits significantly mediate the effect from disturbance on WC and SOC mediates the influence from disturbance on WS. Finally, our results emphasize the potential relationships of tree composition with SOC and soil water retention as compared with soil texture and hence suggest that plants can actively modulate their abiotic contexts after disturbance, which is meaningful for understanding forest health and resistance.
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Morais, Pricila do Prado, Eugenio Yatsuda Arima, Álvaro Nogueira de Souza, Reginaldo Sérgio Pereira, Fabiano Emmert, Rodrigo Montezano Cardoso, Eder Pereira Miguel und Eraldo Aparecido Trondoli Matricardi. „Assessment of Forest Road Models in Concession Areas in the Brazilian Amazon“. Forests 14, Nr. 7 (07.07.2023): 1388. http://dx.doi.org/10.3390/f14071388.
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Forest management aimed at the sustainable use of forest resources is an alternative land use to deforestation and can improve forest conservation in tropical regions. The construction of forest infrastructure, including forest roads, skid trails, and log-landings, is a key factor in minimizing the impacts and forest disturbances typically caused by selective logging activities in tropical forests. In this study, we used field and secondary data to assess the planned and implemented forest infrastructure in a study site of 5723 hectares under a forest concession in the Caxiuanã National Forest, located in the state of Pará, Brazilian Amazon. We tested alternative modeling approaches (the Tomlin and Spanning Tree models) by comparing them with the previously planned and implemented logging infrastructure by a concessionaire timber company (CEMAL Ltd.) in the study site. Our results indicate that the Tomlin model was the best approach for allocating forest roads in the study area, as it demonstrated the optimal balance between financial costs and forest disturbances for timber extraction. Additionally, Minimum Spanning Tree modeling achieved the most favorable results in delineating secondary roads and skid trails in the study site, despite slightly higher financial costs compared to the minimum acceptable costs. This alternative approach to modeling forest infrastructure can contribute to reducing forest disturbances and increasing the economic and ecological sustainability of forest management in tropical forests.
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Marshall, Jordan M., und David S. Buckley. „Effects of Microsites Created by Selective Harvesting on Growth of Microstegium vimineum in a Central Hardwood Forest“. Forest Science 54, Nr. 5 (01.10.2008): 534–42. http://dx.doi.org/10.1093/forestscience/54.5.534.
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Abstract Disturbances related to silvicultural activities are inevitable and may facilitate the spread of established populations of exotic species. Microstegium vimineum is an annual exotic grass that has spread throughout the eastern United States. Different categories of understory microsites resulting from cutting and the operation of logging machines within three selective harvest units were identified and characterized by measuring several environmental variables. M. vimineum was sown within the microsites categorized. Differences in growth of M. vimineum across different microsites were quantified. As percent canopy cover increased, M. vimineum percent cover, mean length, and mean number of nodes decreased. Also, as litter depth increased, M. vimineum percent cover and stem length decreased. In undisturbed microsites in which M. vimineum was not sown, the exotic grass was not a dominant species, whereas in all other microsites created by logging machine operation M. vimineum was a dominant species whether those areas were sown or colonized by wild populations. These results suggest that unique microsites created by logging may facilitate M. vimineum invasion of central hardwood forests. The apparent connection between soil and canopy disturbance and invasion by M. vimineum provides further impetus for careful planning and use of haul roads and skid trails.
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DellaSala, Dominick A., James R. Strittholt, Rebecca Degagne, Brendan Mackey, Jeffery R. Werner, Michelle Connolly, Darwyn Coxson, Andrew Couturier und Heather Keith. „Red-Listed Ecosystem Status of Interior Wetbelt and Inland Temperate Rainforest of British Columbia, Canada“. Land 10, Nr. 8 (23.07.2021): 775. http://dx.doi.org/10.3390/land10080775.
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The Interior Wetbelt (IWB) of British Columbia, which includes the globally rare Inland Temperate Rainforest (ITR), contains primary forests poorly attributed and neglected in conservation planning. We evaluated the IWB and ITR using four IUCN Red List of Ecosystems Criteria: geographic distribution, environmental degradation (abiotic and biotic factors), and likelihood of ecosystem collapse. Clearcut logging (3.2M ha) represented 57% of all anthropogenic disturbances, reducing potential primary forest by 2.7 million ha (28%) for the IWB and 524,003 ha (39%) for the ITR. Decadal logging rates nearly doubled from 5.3% to 10.2% from 1970s–2000s. Core areas (buffered by 100-m from roads and developments) declined by 70% to 95% for the IWB and ITR, respectively. Vulnerable was assigned to karst, the only abiotic factor assessed, because it was associated with rare plants. For biotic factors, Old-Growth Birds were Vulnerable, Southern Woodland Caribou (Rangifer tarandus caribou) habitat and Sensitive Fish were Endangered, and Old-Growth Lichens habitat was Critical. Overall, the IWB was ranked as Endangered and the ITR as Critical with core area collapse possible within 9 to 18 years for the ITR, considered one of the world’s most imperiled temperate rainforests.
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Dalagnol, Ricardo, Oliver L. Phillips, Emanuel Gloor, Lênio S. Galvão, Fabien H. Wagner, Charton J. Locks und Luiz E. O. C. Aragão. „Quantifying Canopy Tree Loss and Gap Recovery in Tropical Forests under Low-Intensity Logging Using VHR Satellite Imagery and Airborne LiDAR“. Remote Sensing 11, Nr. 7 (04.04.2019): 817. http://dx.doi.org/10.3390/rs11070817.
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Logging, including selective and illegal activities, is widespread, affecting the carbon cycle and the biodiversity of tropical forests. However, automated approaches using very high resolution (VHR) satellite data (≤ 1 m spatial resolution) to accurately track these small-scale human disturbances over large and remote areas are not readily available. The main constraint for performing this type of analysis is the lack of spatially accurate tree-scale validation data. In this study, we assessed the potential of VHR satellite imagery to detect canopy tree loss related to selective logging in closed-canopy tropical forests. To do this, we compared the tree loss detection capability of WorldView-2 and GeoEye-1 satellites with airborne LiDAR, which acquired pre- and post-logging data at the Jamari National Forest in the Brazilian Amazon. We found that logging drove changes in canopy height ranging from −5.6 to −42.2 m, with a mean reduction of −23.5 m. A simple LiDAR height difference threshold of −10 m was enough to map 97% of the logged trees. Compared to LiDAR, tree losses can be detected using VHR satellite imagery and a random forest (RF) model with an average precision of 64%, while mapping 60% of the total tree loss. Tree losses associated with large gap openings or tall trees were more successfully detected. In general, the most important remote sensing metrics for the RF model were standard deviation statistics, especially those extracted from the reflectance of the visible bands (R, G, B), and the shadow fraction. While most small canopy gaps closed within ~2 years, larger gaps could still be observed over a longer time. Nevertheless, the use of annual imagery is advised to reach acceptable detectability. Our study shows that VHR satellite imagery has the potential for monitoring the logging in tropical forests and detecting hotspots of natural disturbance with a low cost at the regional scale.
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Tchoumbou, Mélanie A., Elikwo F. N. Malange, Claire T. Tiku, Brice Tibab, Jerome Fru-Cho, Timoléon Tchuinkam, Julius Awah-Ndukum, Damian Anong Nota und Ravinder N. M. Sehgal. „Response of Understory Bird Feeding Groups to Deforestation Gradient in a Tropical Rainforest of Cameroon“. Tropical Conservation Science 13 (Januar 2020): 194008292090697. http://dx.doi.org/10.1177/1940082920906970.
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Birds are crucial in maintaining the balance of many ecosystems and provide various ecological services. Understanding their sensitivity to human disturbances should be prioritized in understudy areas for effective conservation practices. Using mist nets, this study characterized mostly understory bird communities (insectivorous, frugivorous, granivorous, and nectarivorous birds) in three habitat types (pristine forest, selectively logged forest, and young oil palm plantation) in the Talangaye rainforest, Southwest Cameroon. A total of 845 birds belonging to 27 families and 85 species were recorded in the three habitats after 294 h of mist netting. Overall, the mist-netted community was largely dominated by insectivores, followed by frugivores, nectarivores, granivores, and carnivores. Although mean species richness, abundance, and Simpson diversity index did not vary significantly among habitat types, mean species abundance and diversity index decreased in selectively logged forest and young oil palm plantation and species richness increased in both habitats. The species richness, abundance, and diversity index for insectivorous and frugivorous birds were lowest in the young oil palm plantations. For granivores, species richness and abundance increased following selective logging and the establishment of oil palm plantation. The highest mean species richness and diversity index in nectarivores were recorded in the young oil palm plantations. The study showed that selective logging and establishment of oil palm plantation had variable effects on the bird communities in the Talangaye rainforest. Also, the frugivorous birds appeared to be more sensitive to both types of disturbances, while the insectivores were more sensitive to habitat loss/conversion.
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Magrach, Ainhoa, Rebecca A. Senior, Andrew Rogers, Deddy Nurdin, Suzan Benedick, William F. Laurance, Luis Santamaria und David P. Edwards. „Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species“. Proceedings of the Royal Society B: Biological Sciences 283, Nr. 1826 (16.03.2016): 20153008. http://dx.doi.org/10.1098/rspb.2015.3008.
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Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’.
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Kayombo, Canisius John, Henry Joseph Ndangalasi, Richard Alphonce Giliba und Imani Kikoti. „Assessment of Natural Regeneration Potential of Tree Species in Image Forest Reserve, Tanzania“. International Journal of Advanced Research 5, Nr. 1 (22.04.2022): 49–59. http://dx.doi.org/10.37284/ijar.5.1.640.
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Plants natural regeneration is a means to forest recovery after disturbances in a particular ecosystem. Forest recovery in any particular ecosystem depends on the growth stages of tree species. This study assessed the tree species regeneration potential in the disturbed Image Forest Reserve. An assessment was carried out in 170 sample plots of 20 m x 40 m each that were established in the three different land cover types, namely forest (67 plots), woodland (65 plots), and wooded grassland (38 plots). A total of 153 tree species distributed among 59 families and 122 genera were identified. Each of the three land cover types recorded a higher number of saplings than poles and seedlings. The low number of individuals for seedlings was caused by human disturbances that killed them. The human disturbances included wildfires, livestock grazing, and felling trees during logging for timber. The number of poles decreased because several saplings failed to survive due to anthropogenic activities. ANOVA statistical test results revealed a significant difference in trees growth stages (p < 0.05), while there was no significant difference in H' (p > 0.05) in the tree growth stages within the land cover types. Image Forest Reserve accommodates relatively high plant species diversity Therefore, the conservation of Image Forest Reserve will sustain the regenerating tree species and enhance the forest health and sustainability.
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Matricardi, Eraldo A. T., David L. Skole, Marcos A. Pedlowski und Walter Chomentowski. „Assessment of forest disturbances by selective logging and forest fires in the Brazilian Amazon using Landsat data“. International Journal of Remote Sensing 34, Nr. 4 (01.10.2012): 1057–86. http://dx.doi.org/10.1080/01431161.2012.717182.
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Carstairs, Harry, Edward T. A. Mitchard, Iain McNicol, Chiara Aquino, Eric Chezeaux, Médard Obiang Ebanega, Anaick Modinga Dikongo und Mathias Disney. „Sentinel-1 Shadows Used to Quantify Canopy Loss from Selective Logging in Gabon“. Remote Sensing 14, Nr. 17 (27.08.2022): 4233. http://dx.doi.org/10.3390/rs14174233.
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Selective logging is a major cause of forest degradation in the tropics, but its precise scale, location and timing are not known as wide-area, automated remote sensing methods are not yet available at this scale. This limits the abilities of governments to police illegal logging, or monitor (and thus receive payments for) reductions in degradation. Sentinel-1, a C-band Synthetic Aperture Radar satellite mission with a 12-day repeat time across the tropics, is a promising tool for this due to the known appearance of shadows in images where canopy trees are removed. However, previous work has relied on optical satellite data for calibration and validation, which has inherent uncertainties, leaving unanswered questions about the minimum magnitude and area of canopy loss this method can detect. Here, we use a novel bi-temporal LiDAR dataset in a forest degradation experiment in Gabon to show that canopy gaps as small as 0.02 ha (two 10 m × 10 m pixels) can be detected by Sentinel-1. The accuracy of our algorithm was highest when using a timeseries of 50 images over 20 months and no multilooking. With these parameters, canopy gaps in our study site were detected with a false alarm rate of 6.2%, a missed detection rate of 12.2%, and were assigned disturbance dates that were a good qualitative match to logging records. The presence of geolocation errors and false alarms makes this method unsuitable for confirming individual disturbances. However, we found a linear relationship (r2=0.74) between the area of detected Sentinel-1 shadow and LiDAR-based canopy loss at a scale of 1 hectare. By applying our method to three years’ worth of imagery over Gabon, we produce the first national scale map of small-magnitude canopy cover loss. We estimate a total gross canopy cover loss of 0.31 Mha, or 1.3% of Gabon’s forested area, which is a far larger area of change than shown in currently available forest loss alert systems using Landsat (0.022 Mha) and Sentinel-1 (0.019 Mha). Our results, which are made accessible through Google Earth Engine, suggest that this approach could be used to quantify the magnitude and timing of degradation more widely across tropical forests.
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Hua, Junqin, Shuai Lu, Kai Song, Jiayu Wang, Jinfeng Wang und Jiliang Xu. „Effects of Livestock Grazing on Spatio-Temporal Patterns and Behaviour of Reeves’s Pheasant Syrmaticus reevesii“. Animals 12, Nr. 21 (28.10.2022): 2968. http://dx.doi.org/10.3390/ani12212968.
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Protected areas are seeing an increase in anthropogenic disturbances in the world. Previous studies have demonstrated the impact of livestock grazing and human presence on the habitat use of birds, whereas little is known about the effect of free-ranging livestock on bird behaviour. Reeves’s Pheasant (Syrmaticus reevesii) is endemic to China and has been threatened by habitat loss and fragmentation, illegal logging, and human disturbance over the past 20 years. Based on camera trapping in the Liankangshan National Nature Reserve (LKS) and the Zhonghuashan Birds Provincial Nature Reserve (ZHS), we explore the effects of livestock grazing and human activities on the spatio-temporal distribution and behavioural patterns of Reeves’s Pheasant. Livestock does not appear to affect habitat use by the pheasant but changes its behavioural patterns. In addition, pheasants in areas with livestock foraged mostly during the early morning, while in areas without livestock, they foraged at dusk. Therefore, the study concludes that livestock intensity in nature reserves may have reduced pheasant suitability through altered patterns of vigilance and foraging behaviour.
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Fonkwo, Sylvie Nguedem, Ndi Collins Fai und Tonjock Rosemary Kinge. „Population status and anthropogenic disturbances of forest elephants (Loxodonta cyclotis Matschie, 1900) in Nki National park and its environs, east region, Cameroon“. International Journal of Biological and Chemical Sciences 17, Nr. 2 (31.05.2023): 646–55. http://dx.doi.org/10.4314/ijbcs.v17i2.28.
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African elephants play important roles in both the natural and human worlds: ecologically as a keystone species, economically as drivers of tourism and culturally as icons of the African continent. Increasingly, elephant populations are threatened by poaching for ivory, human-elephant conflict, habitat loss and fragmentation, and isolation of populations. This study was carried out to estimate the population of forest elephants and determine the human threats to their population. Data was collected along eleven 2 Km line transects and reconnaissance walk as well as administration of semi-structured questionnaires. Results obtained indicated a mean dung pile of 6.0 boli/Km2. Elephant density, thus, was 0.14 elephant/km2, translated to 428 (217-897) individual elephants. The main threats on elephant population with their percentage acceptance were identified to be non-respect of law enforcement (94.4%), hunting for bushmeat (92.5%), hunting for ivory (91.6%), lack of a management plan (73.8%), logging (68.2%) and road construction (43.0%). It was therefore concluded that there is a reduction in elephant population in the park from 565 in 2015 to 428 in 2021. Thus, it is recommended that increased law enforcement, surveillance and the setting up of constant and long-term monitoring programs be carried out in the park.
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Suryatmojo, Hatma, und Ken’ichirou Kosugi. „River Buffer Effectiveness in Controlling Surface Runoff Based on Saturated Soil Hydraulic Conductivity“. Water 13, Nr. 17 (30.08.2021): 2383. http://dx.doi.org/10.3390/w13172383.
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In tropical Indonesia, rainforests are managed by an intensive forest management system (IFMS). The IFMS has promoted selective logging for timber harvesting and intensive line planting to enrich the standing stock. The implementation of the IFMS has reduced the forest canopy cover, disturbed the surface soil, changed the soil hydraulic properties, and increased direct runoff and soil erosion. Investigation of the IFMS impact on soil hydraulic properties and the generation of surface runoff using a saturated hydraulic conductivity model is needed. Soil hydraulic properties were investigated on 11 plots, including one virgin forest plot and 10 plots at different operational periods of the IFMS. A two-dimensional saturated soil water flow simulation was applied to generate surface runoff from different periods of the IFMS. The main parameters of canopy cover, net rainfall, and saturated hydraulic conductivity were used in the simulations. A simulation scenario of a surface runoff hydrograph in different forest operations was used to analyze the river buffer effectiveness. The results showed that fundamental IFMS activities associated with mechanized selective logging and intensive line planting have reduced the soil hydraulic conductivity within the near-surface profile. The recovery time for near-surface Ks on non-skidder tracks was between 10 and 15 years, whereas on the skidder tracks it was more than 20 years. Forest disturbances have altered the typical surface hydrological pathways, thereby creating the conditions for more surface runoff on disturbed surfaces than on undisturbed surfaces. Maintaining the buffer area is an effective means to reduce the peak discharge and surface runoff in the stream channel.