Littérature scientifique sur le sujet « Anthropogenic disturbances and selective logging »

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Les forêts tropicales sont confrontées à des perturbations anthropiques fréquentes et intenses, telles que l'exploitation sélective - l'abattage de quelques arbres dans des forêts anciennes, tandis que le reste du peuplement se régénère naturellement. De nombreuses études ont été menées sur la reconstitution des stocks de carbone et de bois, en raison d'un intérêt pour l'atténuation du changement climatique et la rentabilité de l'exploitation. Malgré le rôle crucial de la biodiversité pour le maintien et le fonctionnement des écosystèmes - et sa valeur intrinsèque - peu d'études ont été menées sur l'impact de l'exploitation sélective sur la biodiversité. Par conséquent, cette thèse vise à caractériser la réponse de la diversité et de la composition des arbres à l'exploitation forestière dans les forêts tropicales américaines.Grâce aux inventaires forestiers (1986-2021, diamètre à hauteur de poitrine ≥ 10 cm) de la station de Paracou (Guyane française), nous avons construit un cadre bayésien de modélisation des trajectoires de la diversité et de la composition des arbres après exploitation : Paracou a été perturbé par des traitements sylvicoles de différentes intensités en 1986-1987. Nous avons propagé l'incertitude associée à la détermination botanique et aux mesures des traits fonctionnels, et modélisé les trajectoires de diversité et de composition taxonomique, phylogénétique et fonctionnelle des arbres au niveau de l'espèce, par rapport à leurs niveaux pré-perturbation. En outre, nous avons évalué l'effet des caractéristiques des communautés d'arbres pré-perturbation, des conditions biophysiques et des propriétés de la perturbation sur nos trajectoires d'attributs forestiers. Deuxièmement, nous avons utilisé une version simplifiée du cadre de modélisation susmentionné sur des inventaires forestiers à long terme provenant de parcelles situées au Costa Rica et dans trois pays amazoniens (Observatorio de los Ecosistemas Forestales de Costa Rica et Tropical managed Forest Observatory). Nous avons modélisé leurs trajectoires de diversité et de composition taxonomique et fonctionnelle après exploitation au niveau du genre, à partir desquelles nous avons extrait des indicateurs sur la période d'inventaire de chaque site. Nous avons ensuite évalué l'effet de la structure de la communauté d'arbres pré-perturbation et des propriétés de la perturbation sur ces indicateurs. Bien que plus variables dans la seconde étude ayant une portée géographique plus large, nous avons observé des tendances similaires dans les deux études : la diversité a majoritairement augmenté après exploitation et les communautés d'arbres sont principalement passées de stratégies de conservation à des stratégies d'acquisition des ressources. Ces changements semblent provenir du recrutement abondant et momentané d'espèces de début de succession présentant des caractéristiques d'acquisition des ressources, ce qui leur confère un avantage compétitif lorsque l'intensité de perturbation - i.e., disponibilité de la lumière et de l'espace - augmente. En effet, les changements de diversité et composition ont augmenté dans les deux études avec l'intensité de perturbation, alors que les autres descripteurs n'ont pas eu d'effet significatif. Troisièmement, suite à l'importance de l'intensité de perturbation dans les études précédentes, nous avons développé un cadre commun de modélisation des trajectoires de forêts perturbées à travers un gradient d'intensité de perturbation. Nous avons testé notre approche de modélisation sur des inventaires forestiers de long-terme du Costa Rica et de Guyane française, après exploitation sélective, agriculture, et coupe à blanc suivie d'un feu.Ces résultats ouvrent des perspectives sur les méthodes d'évaluation de la réponse forestière aux perturbations, la réponse des forêts elle-même et ses processus écologiques sous-jacents, et l'intérêt des forêts perturbées pour les plans de gestion et de conservation forestières
Tropical forests face more frequent and intense anthropogenic disturbances, such as selective logging, namely the felling and harvesting of a few commercially valuable trees in old-growth forests, while the remaining stand is left for natural regeneration. Many studies focused on this regeneration, particularly on the recovery of carbon and timber stocks, most likely due to a strong interest in climate change mitigation and logging profitability. However, despite the crucial role of biodiversity for ecosystem maintenance and functioning - and its intrinsic value - there have been few studies on the impact of selective logging on biodiversity. Therefore, this thesis - organised in three studies - aimed at characterising the response of tree diversity and composition to logging in tropical American forests.First, we drew upon the long-term forest inventories (1986-2021, trees with a diameter at breast height ≥ 10 cm) from Paracou experimental station to build a Bayesian modelling framework of tree diversity and composition trajectories after selective logging. Paracou is located in French Guiana and was disturbed by silvicultural treatments of different intensities in 1986-1987. We propagated in our Bayesian framework the uncertainty associated with botanical determination and functional trait measurements, and modelled Paracou trajectories of taxonomic, phylogenetic and functional tree diversity and composition at the species level, relatively to their pre-disturbance levels. Additionally, we assessed the effect of pre-disturbance tree community characteristics, biophysical conditions and disturbance properties on our forest attribute trajectories. Second, we used a simplified version of the aforementioned Bayesian modelling framework on long-term forest inventories from sample plots located in Costa Rica and three Amazonian countries (respectively belonging to the Observatorio de los Ecosistemas Forestales de Costa Rica and the Tropical managed Forest Observatory). We modelled their post-logging trajectories of taxonomic and functional tree diversity and composition at the genus level, from which we extracted indicators solely over the inventory timespan of each site. We then assessed the effect of pre-disturbance tree community structure and disturbance properties on such indicators. While more variable in the second study with a broader geographical scope than in the first one, we observed similar trends in both studies: diversity mostly increased after logging and tree communities mainly shifted from resource-conservative strategies to resource-acquisitive strategies. Such changes appeared to be driven by the abundant and transient recruitment of early-successional species with acquisitive trait values, which provided them with a competitive advantage as disturbance intensity - i.e., light and space availability - increased. Indeed, changes in diversity and composition increased in both studies with disturbance intensity whereas disturbance selectivity, pre-disturbance tree community characteristics and biophysical conditions had no significant effect. Third, building up on the paramount importance of disturbance intensity in the two previous studies, we developed an original Bayesian hierarchical model of recovery trajectories, considering disturbed forests in a common framework, through a disturbance intensity gradient. We tested our modelling approach on data from two long-term experiments in Costa Rica and French Guiana, set up after selective logging, agriculture, and clearcutting and fire.Overall, these results opened various perspectives on the methods used to evaluate forest response to disturbance, the forest response itself and the ecological processes underlying forest succession, and how disturbed forests could be considered in forest management and conservation plans

From space, much of Indonesia appeared to be on fire. One of the strongest El Niño/Southern Oscillation (ENSO) events of the twentieth century had generated drought conditions in the fall of 1997 and early 1998. These conditions, probably in concert with the impacts of logging, resulted in what has been called the largest fire disaster ever observed (Siegert et al. 2001). The powerful 1997–8 ENSO also led to extensive fires in Amazonia. The humid tropics, home to Earth’s greatest concentrations of biodiversity, had long been thought to be fire resistant due to high-moisture levels in the leaf litter and the humidity of the understory. The massive fires of 1997–8 increased our understanding of the complex interactions between fire and humid tropical forests. Since the late 1990s, a new synthesis has emerged linking ENSO events, drought, logging, and fire in the wet tropics. This synthesis has sought to understand the impacts of these phenomena on tropical environments and also explain the role humans play in tropical fires and fire impacts. Remote sensing has been an important tool in forging this new synthesis of understanding. For example, NOAA’s workhorse AVHRR sensor, the SeaWiFS sensor, and NASA’s TOMS instrument were among the satellite tools available to provide imagery of the dramatic events of 1997–8. In this chapter, we discuss the potential for remote sensing to detect, monitor, and increase our understanding of certain disturbance mechanisms affecting ecosystems. We focus on fires and floods, adding shorter sections at the end on two other drivers of disturbance, volcanoes and dams. A key challenge lies in understanding the degree to which logging, even selective logging, is interacting with periodic droughts to drive fires in humid forests. Are humid tropical forests essentially immune to fire unless disturbed by human logging, or have they always been subject to climate-induced droughts and subsequent fires? The answer is crucial in determining our impact on these great storehouses of biodiversity and holds major implications for forest management. Part of the answer lies in looking backward in time.

Reservoir management utilizes time-lapse pressure data that is captured over years in order to monitor reservoir development. Several methods can be used to establish field-wide hydraulic lateral and/or vertical connectivity: well testing, monitoring of permanent downhole gauges, wireline and LWD formation testers. While a typical formation pressure survey provides information about reservoir depletion or charge (production or injection), in a field with several wells it is not clearly understood where the pressure disturbances are coming from, which can hamper further field development decision making in terms of infill well selection and drilling. A novel method is introduced where a Formation Pressure While Drilling (FPWD) tool is run in UKCS wells and used to acquire interference data while drilling. Initially reservoir pressures are acquired as soon as practically possible after drilling. Having established these benchmark pressures, nearby injectors and/or producers can be started or shut in one at a time. Drilling is then resumed and after a certain time has elapsed since the benchmark pressure acquisition (typically at least 12 hours), the pressure measurements are repeated using the FPWD tool to evaluate the influence of the created transients in order to prove or disprove either lateral or vertical hydraulic connectivity across reservoirs. This way, the influence of a single offset well is evaluated in real time over the reservoir being currently drilled. This helps in the determination of interference pattern whereby injector wells can be judged for selective zone injections and producers can be rated in terms of zonal contribution which can help in completion design. These direct pressure measurements can illuminate reservoir pressure complexity seen in mature fields and provide operators with the means to safely and effectively construct wells to develop brownfields. The pressure changes obtained are used not only by reservoir engineers as an additional source of dynamic data into the reservoir simulation model but also help geologists in refining the geological or basin model. Two applications of real-time interference testing using FPWD from a recent drilling campaign are shown. In the first application, communication between wells is tested to reduce the risk of accidentally completing a well in an area of the field that experiences insufficient injection support. In the second application, real-time interference testing is used to identify a specific zone in a multi-layered reservoir sequence in order to enable selective completion.