scholarly journals Gamebird responses to anthropogenic forest fragmentation and degradation in a southern Amazonian landscape

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3442 ◽  
Author(s):  
Fernanda Michalski ◽  
Carlos A. Peres
Keyword(s):  
Forest Fragmentation ◽  
Census Data ◽  
Forest Disturbance ◽  
Selective Logging ◽  
Forest Birds ◽  
Line Transect ◽  
Forest Patches ◽  
Forest Patch ◽  
Species Persistence ◽  
Gamebird Species

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.

scholarly journals The implications of selective logging and forest fragmentation for the conservation of avian diversity in evergreen forests of south-west Ghana

2005 ◽  
Vol 15 (1) ◽  
pp. 27-52 ◽  
Author(s):  
LARS H. HOLBECH
Keyword(s):  
Forest Fragmentation ◽  
Management Practices ◽  
Selective Logging ◽  
Global Perspective ◽  
Bird Diversity ◽  
Line Transect ◽  
Tropical Forestry ◽  
Regeneration Time ◽  
Conservation Implications ◽  
South West

The urgent global objective of developing sustainable tropical forestry management practices, which also target biodiversity conservation, requires rapid comparative studies that address both biogeography and logging practices. This paper examines avifaunal implications (focusing on species diversity and composition) of forest fragmentation and selective logging, by comparing 15 selected reserved forests in south-west Ghana. The regeneration time since last logging varied from 0 (logging continuing) to 21 years, with one unlogged site as control. Extraction levels ranged between 0.20 and 3.75 trees per ha (mean 0.90). Bird sampling involved understorey mist-netting and standardized line-transect walks, which respectively accumulated 8,348 captures and 22,452 single records of 147 species. Mist-net data showed that understorey bird diversity was positively correlated with logging intensity up to c. 3 trees per ha, reflecting increased influx of open-land species and a persistence of forest obligates during the first 5 years after logging. The overall abundance of forest interior species tended to decrease 5–10 years after logging, but recovered fairly well thereafter. Canopy birds were generally more logging-resilient. Rare forest obligates with high conservation importance were found to be equally abundant in virgin and logged, large forests, whereas these birds were poorly represented in small heavily logged forests. The results are compared with findings from other regions, and conservation implications and constraints are discussed in a global perspective. Finally, recommendations on size-related sustainable extraction levels and regeneration time are presented for the Upper Guinea Forest.

scholarly journals Size matters: the effects of forest fragmentation and resource availability on the endemic Sumba Hornbill Aceros everetti

2004 ◽  
Vol 14 (S1) ◽  
pp. S23-S37 ◽  
Author(s):  
ARNOLD F. SITOMPUL ◽  
MARGARET F. KINNAIRD ◽  
TIMOTHY G. O'BRIEN
Keyword(s):  
Forest Fragmentation ◽  
Resource Availability ◽  
Patch Size ◽  
Line Transect ◽  
Forest Fragments ◽  
Forest Patch ◽  
Canopy Trees ◽  
Food Species ◽  
Abundance And Distribution ◽  
Made In

We examined the influence of forest fragmentation and resource availability on the abundance and distribution of Sumba Hornbill Aceros everetti, a large, canopy-dwelling bird endemic to Sumba Island, Indonesia. Hornbill numbers were estimated monthly from August 1998 to September 1999. Estimates were made in three large (≥1,000 ha) and three small (<1,000 ha) forest fragments, using a standard line transect method. Phenological patterns of canopy trees were assessed in 10 × 50 m plots. Our data indicated that forest patch size may be a better predictor of Sumba Hornbill abundance and distribution than overall resource availability. Hornbills occurred at higher densities in large forests (6/km2) than small forests (2.4/km2). Small forests produced more fruit/ha per month but lacked a number of important hornbill food species. Monthly fruit availability in large and small forest fragments had no significant effect on fluctuations in hornbill density. However, hornbill densities were significantly higher in forests with high densities of strangling figs, after controlling for patch size, and in larger forests hornbill densities correlated with the abundance of ripe figs. We hypothesize that small patches still have conservation value if they are within hornbill ranging distance, and speculate that Sumba's forests are in a dynamic phase before the full impact of fragmentation has been expressed.

scholarly journals Forest Fragmentation and Connectivity in Virginia Between 2001 and 2011

2018 ◽  
Vol 11 (3) ◽  
pp. 98-119
Author(s):  
Iris E. M. Fynn ◽  
James Campbell
Keyword(s):  
Forest Fragmentation ◽  
Human Activities ◽  
Road Density ◽  
Forest Patches ◽  
Forest Patch ◽  
Topographic Slope ◽  
Annual Population ◽  
Data Source

Abstract With an annual population growth rate currently estimated at about 5 %, Virginia presents an ideal case study for anthropogenic environmental disturbances. Urbanization as a result of increasing human activities has led to fragmentation of many crucial habitats, especially forests. Analysis of the extent to which forest fragmentation and connectivity have occurred in Virginia and corresponding changes associated with these processes, is relevant for conserving forest habitats and the biodiversity that they support. This study applies FRAGSTATS, a software system developed to assess forest fragmentation and connectivity, in combination with ArcGIS, to identify changes in forest patch metrics for Virginia over a ten-year interval (2001, 2006 and 2011) using National Land Cover Datasets (NLCD) maps as data source. Results show that, over ten years, forest patches have significantly declined in size, while the number of forest patches and total length of edge areas have increased over time. Results of this study show that road density in Virginia has no significant effect on forest fragmentation between 2001 and 2011. Analysis using ArcGIS revealed that sizes of core forest areas in Virginia are declining, and that these reductions match local topographic slope. This is because the steepness of the slope of an area dictates the degree of human activities in that area. These results suggest that urban sprawl associated with areas with gentler slopes, may have significant, long-term consequences for natural forest ecosystems and ultimately, biodiversity conservation.

scholarly journals Spatial Analysis of the Drivers, Characteristics, and Effects of Forest Fragmentation

2021 ◽  
Vol 13 (6) ◽  
pp. 3246
Author(s):  
Zoe Slattery ◽  
Richard Fenner
Keyword(s):  
Forest Fragmentation ◽  
Forest Fires ◽  
Geographical Information ◽  
Agricultural Expansion ◽  
Forest Patches ◽  
Mato Grosso ◽  
Remote Imaging ◽  
Landscape Characteristics ◽  
High Level

Building on the existing literature, this study examines whether specific drivers of forest fragmentation cause particular fragmentation characteristics, and how these characteristics can be linked to their effects on forest-dwelling species. This research uses Landsat remote imaging to examine the changing patterns of forests. It focuses on areas which have undergone a high level of a specific fragmentation driver, in particular either agricultural expansion or commodity-driven deforestation. Seven municipalities in the states of Rondônia and Mato Grosso in Brazil are selected as case study areas, as these states experienced a high level of commodity-driven deforestation and agricultural expansion respectively. Land cover maps of each municipality are created using the Geographical Information System software ArcGIS Spatial Analyst extension. The resulting categorical maps are input into Fragstats fragmentation software to calculate quantifiable fragmentation metrics for each municipality. To determine the effects that these characteristics are likely to cause, this study uses a literature review to determine how species traits affect their responses to forest fragmentation. Results indicate that, in areas that underwent agricultural expansion, the remaining forest patches became more complex in shape with longer edges and lost a large amount of core area. This negatively affects species which are either highly dispersive or specialist to core forest habitat. In areas that underwent commodity-driven deforestation, it was more likely that forest patches would become less aggregated and create disjunct core areas. This negatively affects smaller, sedentary animals which do not naturally travel long distances. This study is significant in that it links individual fragmentation drivers to their landscape characteristics, and in turn uses these to predict effects on species with particular traits. This information will prove useful for forest managers, particularly in the case study municipalities examined in this study, in deciding which species require further protection measures. The methodology could be applied to other drivers of forest fragmentation such as forest fires.

scholarly journals Selective logging reduces body size in omnivorous and frugivorous tropical forest birds

2021 ◽  
Vol 256 ◽  
pp. 109036
Author(s):  
Simone Messina ◽  
David Costantini ◽  
Suzanne Tomassi ◽  
Cindy C.P. Cosset ◽  
Suzan Benedick ◽  
...  
Keyword(s):  
Body Size ◽  
Tropical Forest ◽  
Selective Logging ◽  
Forest Birds

The consequences of selective logging for Bornean lowland forest birds

1992 ◽  
Vol 335 (1275) ◽  
pp. 443-457 ◽  
Keyword(s):  
Population Dynamics ◽  
Bird Species ◽  
Selective Logging ◽  
Forest Birds ◽  
Primary Forest ◽  
Bird Conservation ◽  
Lowland Forest ◽  
Dipterocarp Forest ◽  
Logged Forest ◽  
Lowland Dipterocarp Forest

In lowland dipterocarp forest in Sabah, Malaysia, most primary forest bird species were present in areas selectively logged eight years previously. However, certain taxa, notably flycatchers, woodpeckers, trogons and wren-babblers, became comparatively rare. In contrast, nectarivorous and opportunistic frugivorous species were significantly more abundant. Few species appeared to change foraging height, but netting rates suggest that the activity of some species had increased, or that some birds ranged over larger areas after logging. Although there is still much to be learned about the survival of birds in logged forest, large areas of this habitat are important for bird conservation. However, the susceptibility of logged forest to fire, and our present incomplete understanding of bird behaviour and population dynamics in logged forests mean that they should not be considered by conservationists as alternatives to reserves of primary forest.

scholarly journals A model for the importance of large arborescent palms in the dynamics of seasonally-dry amazonian forests

2005 ◽  
Vol 5 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Rodolfo Salm ◽  
Euphly Jalles-Filho ◽  
Cynthia Schuck-Paim
Keyword(s):  
Forest Regeneration ◽  
Forest Canopy ◽  
Forest Succession ◽  
Secondary Forest ◽  
Forest Disturbance ◽  
Dry Forest ◽  
Forest Patch ◽  
Seasonally Dry ◽  
Palm Trees ◽  
Amazonian Forests

In this study we propose a model that represents the importance of large arborescent palms in the dynamics of seasonally-dry Amazonian forests. Specifically, the model is aimed at guiding the investigation of the role of large arborescent palms on forest regeneration and succession. Following disturbance, the high level of luminosity reaching recently formed forest gaps favors the quick proliferation of shade-intolerant lianas that, by casting shade on the crowns of mature forest trees and increasing tree-fall probability, suppress forest succession. Due to their columnar architecture palm trees are, however, not severely affected by vines. As the palms grow, the canopy at the gaps becomes gradually higher and denser, progressively obstructing the passage of light, thus hindering the growth of shade-intolerant lianas and enabling late-successional tree development and forest regeneration. Owing to the long time associated with forest regeneration, the model cannot be tested directly, but aspects of it were examined with field data collected at an Attalea maripa-rich secondary forest patch within a matrix of well-preserved seasonally-dry forest in the Southeastern Amazon. The results indicate that (1) forest disturbance is important for the recruitment of large arborescent palms species, (2) these palms can grow rapidly after an event of disturbance, restoring forest canopy height and density, and (3) secondary forest dominated by palm trees species may be floristically similar to nearby undisturbed forests, supporting the hypothesis that the former has undergone regeneration, as purported in the model.

Effects of forest fragmentation on genetic variation in endemic understory forest birds in central Madagascar

2000 ◽  
Vol 141 (2) ◽  
pp. 152-159 ◽  
Author(s):  
Aristide Andrianarimisa ◽  
Lutz Bachmann ◽  
Jörg U. Ganzhorn ◽  
Steven M. Goodman ◽  
Jürgen Tomiuk
Keyword(s):  
Genetic Variation ◽  
Forest Fragmentation ◽  
Forest Birds

scholarly journals Effects of Forest Disturbance on Vegetation Structure and Above-Ground Carbon in Three Isolated Forest Patches of Taita Hills

2016 ◽  
Vol 06 (02) ◽  
pp. 142-161 ◽  
Author(s):  
Chemuku Wekesa ◽  
Nereoh Leley ◽  
Elias Maranga ◽  
Bernard Kirui ◽  
Gabriel Muturi ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Forest Disturbance ◽  
Forest Patches ◽  
Taita Hills

scholarly journals Forest birds respond to the spatial pattern of exurban development in the Mid-Atlantic region, USA

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2039 ◽  
Author(s):  
Marcela Suarez-Rubio ◽  
Todd R. Lookingbill
Keyword(s):  
Spatial Pattern ◽  
Spatial Scale ◽  
Forest Fragmentation ◽  
Spatial Scales ◽  
The United States ◽  
Forest Edge ◽  
Forest Birds ◽  
Bird Diversity ◽  
Forest Loss ◽  
Exurban Development

Housing development beyond the urban fringe (i.e., exurban development) is one of the fastest growing forms of land-use change in the United States. Exurban development’s attraction to natural and recreational amenities has raised concerns for conservation and represents a potential threat to wildlife. Although forest-dependent species have been found particularly sensitive to low housing densities, it is unclear how the spatial distribution of houses affects forest birds. The aim of this study was to assess forest bird responses to changes in the spatial pattern of exurban development and also to examine species responses when forest loss and forest fragmentation were considered. We evaluated landscape composition around North American Breeding Bird Survey stops between 1986 and 2009 by developing a compactness index to assess changes in the spatial pattern of exurban development over time. Compactness was defined as a measure of how clustered exurban development was in the area surrounding each survey stop at each time period considered. We used Threshold Indicator Taxa Analysis to detect the response of forest and forest-edge species in terms of occurrence and relative abundance along the compactness gradient at two spatial scales (400-m and 1-km radius buffer). Our results showed that most forest birds and some forest-edge species were positively associated with high levels of compactness at the larger spatial scale; the proportion of forest in the surrounding landscape also had a significant effect when forest loss and forest fragmentation were accounted for. In contrast, the spatial configuration of exurban development was an important predictor of occurrence and abundance for only a few species at the smaller spatial scale. The positive response of forest birds to compactness at the larger scale could represent a systematic trajectory of decline and could be highly detrimental to bird diversity if exurban growth continues and creates more compacted development.

Sign in / Sign up

Export Citation Format

Share Document