scholarly journals The Relative Importance of Human Disturbance, Environmental and Spatial Factors on the Community Composition of Wetland Birds

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3448
Author(s):  
Seid Tiku Mereta ◽  
Pieter Lemmens ◽  
Luc De Meester ◽  
Peter L. M. Goethals ◽  
Pieter Boets
Keyword(s):  
Community Composition ◽  
Human Disturbance ◽  
Environmental Variables ◽  
Variation Partitioning ◽  
Bird Species ◽  
Bird Community ◽  
Minor Role ◽  
Compositional Variation ◽  
Relative Importance ◽  
Spatial Factors

The present study investigates the relative importance of human disturbance, local environmental and spatial factors on variations in bird community composition in natural Ethiopian wetlands with high biodiversity conservation value. We quantified bird abundances, local environmental variables and human disturbances at 63 sites distributed over ten wetlands in two subsequent years. Variation partitioning analyses were used to explore the unique and shared contributions of human disturbance, local environmental variables and spatial factors on variations in community compositions of wetland bird species. Local environmental variables explained the largest amount of compositional variation of wetland bird species. Productivity-related variables were the most important local environmental variables determining bird community composition. Human disturbance was also an important determinant for wetland bird community composition and affected the investigated communities mainly indirectly through its effect on local environmental conditions. Spatial factors only played a minor role in variations in bird community composition. Our study highlights the urgent need for integrated management approaches that consider both nature conservation targets and socio-economic development of the region for the sustainable use and effective conservation of wetland resources.

scholarly journals Forest and biodiversity: a multiscale analysis of forest bird community in Varese district

2013 ◽  
Vol 82 (1-2) ◽  
Author(s):  
Alessandra Gagliardi ◽  
Damiano Preatoni ◽  
Fabio Saporetti ◽  
Guido Tosi
Keyword(s):  
Community Composition ◽  
Landscape Metrics ◽  
Environmental Variables ◽  
Multiscale Analysis ◽  
Bird Species ◽  
Bird Community ◽  
Multiscale Approach ◽  
Forest Bird ◽  
Area Data

Forests represent more than 45% of the Varese district area. Data of forest bird community composition are correlated with the appearance of woods. With a multiscale approach (1 km2 units and territories) some landscape metrics are analysed, in order to evaluate the influence of environmental variables on bird species.

scholarly journals Fire effects on the composition of a bird community in an amazonian Savanna (Brazil)

2005 ◽  
Vol 65 (4) ◽  
pp. 683-695 ◽  
Author(s):  
R. Cintra ◽  
T. M. Sanaiotti
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Spatial Scales ◽  
Bird Species ◽  
Bird Community ◽  
Fire Effects ◽  
Bird Abundance ◽  
Bird Species Richness ◽  
Byrsonima Crassifolia ◽  
Mist Net

The effects of fire on the composition of a bird community were investigated in an Amazonian savanna near Alter-do-Chão, Pará (Brazil). Mist-net captures and visual counts were used to assess species richness and bird abundance pre- and post-fire in an approximately 20 ha area. Visual counts along transects were used to survey birds in an approximately 2000 ha area in a nearby area. Results using the same method of ordination analysis (multidimensional scaling) showed significant effects of fire in the 20 ha and 2000 ha areas and strongly suggest direct effects on bird community composition. However, the effects were different at different spatial scales and/or in different years, indicating that the effects of fire vary spatially and/or temporally. Bird community composition pre-fire was significantly different from that found post-fire. Using multiple regression analysis it was found that the numbers of burned and unburned trees were not significantly related to either bird species richness or bird abundance. Two months after the fire, neither bird species richness nor bird abundance was significantly related to the number of flowering trees (Lafoensia pacari) or fruiting trees (Byrsonima crassifolia). Since fire is an annual event in Alter-do-Chão and is becoming frequent in the entire Amazon, bird community composition in affected areas could be constantly changing in time and space.

scholarly journals Soil resources and topography shape local tree community structure in tropical forests

2013 ◽  
Vol 280 (1753) ◽  
pp. 20122532 ◽  
Author(s):  
Claire A. Baldeck ◽  
Kyle E. Harms ◽  
Joseph B. Yavitt ◽  
Robert John ◽  
Benjamin L. Turner ◽  
...  
Keyword(s):  
Community Structure ◽  
Tropical Forests ◽  
Environmental Variables ◽  
Variation Partitioning ◽  
Compositional Variation ◽  
Habitat Filtering ◽  
Soil Resources ◽  
Soil Resource ◽  
Compositional Structure ◽  
Tree Community

Both habitat filtering and dispersal limitation influence the compositional structure of forest communities, but previous studies examining the relative contributions of these processes with variation partitioning have primarily used topography to represent the influence of the environment. Here, we bring together data on both topography and soil resource variation within eight large (24–50 ha) tropical forest plots, and use variation partitioning to decompose community compositional variation into fractions explained by spatial, soil resource and topographic variables. Both soil resources and topography account for significant and approximately equal variation in tree community composition (9–34% and 5–29%, respectively), and all environmental variables together explain 13–39% of compositional variation within a plot. A large fraction of variation (19–37%) was spatially structured, yet unexplained by the environment, suggesting an important role for dispersal processes and unmeasured environmental variables. For the majority of sites, adding soil resource variables to topography nearly doubled the inferred role of habitat filtering, accounting for variation in compositional structure that would previously have been attributable to dispersal. Our results, illustrated using a new graphical depiction of community structure within these plots, demonstrate the importance of small-scale environmental variation in shaping local community structure in diverse tropical forests around the globe.

scholarly journals Seasonal variation in the relative importance of assembly processes in marine fish communities as determined by environmental DNA analyses

2021 ◽  
Author(s):  
Naoto Shinohara ◽  
Yuki Hongo ◽  
Momoko Ichinokawa ◽  
Shota Nishijima ◽  
Shuhei Sawayama ◽  
...  
Keyword(s):  
Marine Fish ◽  
Seasonal Changes ◽  
Variation Partitioning ◽  
Environmental Filtering ◽  
Fish Communities ◽  
Environmental Dna ◽  
Compositional Variation ◽  
Short Time Scale ◽  
Relative Importance ◽  
Spatial Processes

Compositional variation among local communities is a result of environmental (e.g., environmental filtering) and spatial (e.g., dispersal limitation) processes. Growing evidence suggests that their relative importance varies temporally, but little is known about the short-time scale dynamics, that is, seasonality. Using marine fish communities in a Japanese bay as a model system, we tested the hypothesis that seasonal changes in the environment induce a shift in the relative importance of environmental and spatial processes. We used one-year monthly monitoring data obtained using environmental DNA and conducted a variation partitioning analysis to decompose the two processes. The relative importance of environmental and spatial processes was comparable averaged over the year but changed seasonally. During summer, when lower dissolved oxygen concentrations may adversely affect organisms, species composition was more explained by space despite larger environmental heterogeneity than in other seasons. This suggests that environmental processes weakened during the season with extremely severe environments, likely due to the random loss of individuals. We conclude that the assembly processes of communities of mobile organisms, such as fishes, can shift even within a year in response to seasonal changes in environmental severity. The results also indicate the applicability of eDNA techniques for community assembly studies.

scholarly journals Conserving native trees increases native bird diversity and community composition on commercial office developments

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Karen Dyson
Keyword(s):  
Community Composition ◽  
Environmental Gradients ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Bird Diversity ◽  
Bird Conservation ◽  
Tree Protection ◽  
Matrix Habitat ◽  
Site Use

Abstract In cities, woody vegetation provides critical shelter, nesting and foraging habitat for bird species of interest. Human actions—including development and landscaping choices—determine vegetation community composition and structure, making these choices critically important to urban bird conservation. A better understanding of how bird communities are impacted by parcel-scale actions can help guide policy and management best practices to improve matrix habitat quality and quantity. Here, I examined how bird habitat use varies along a vegetation gradient created by different development and landscaping choices. I surveyed 20 commercial office developments near Seattle in the Puget Trough region of Washington, USA selected using stratified random sampling, where I quantified bird communities and observed feeding behavior. I used GLMM and PERMANOVA models with data likelihood metrics to identify the best supported variables for bird site use, along with TITAN models to identify changes in community composition along environmental gradients. I found that measures of bird effective species richness and bird community are positively influenced by the presence of more native conifers, including the presence of a stand predating development and the height and density of native conifers. Measures of the native bird community are negatively influenced by higher non-native tree density. In contrast to prior research, top-down landscape-scale variables did not explain variation in measures of the bird community on office developments. Importantly, I found that birds are associated with the same habitat on office developments as observed elsewhere. Together, my findings suggest an important role for developers, land owners, landscape architects, and tree protection policy in bird conservation.

scholarly journals Birds surveyed in the harvested and unharvested areas of a reduced-impact logged forestry concession, located in the lowland subtropical humid forests of the Department of Santa Cruz, Bolivia

Check List ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 43 ◽  
Author(s):  
Adam Felton ◽  
Bennett A. Hennessey ◽  
Annika M. Felton ◽  
David B. Lindenmayer
Keyword(s):  
Community Composition ◽  
Bird Species ◽  
Bird Community ◽  
Font Size ◽  
Santa Cruz ◽  
Wet Season ◽  
Point Count ◽  
Logging Effects ◽  
Logged Forest ◽  
Reduced Impact Logging

As part of a larger study of reduced-impact logging effects on bird community composition, we surveyed birds from December to February during the 2003-2004 wet-season within harvested and unharvested blocks of the La Chonta forestry concession, Department of Santa Cruz, Bolivia. The logged forest was harvested using reducedimpact logging techniques between one and four years previously. During point count surveys, we identified 5062 individual birds, belonging to 155 species, and 33 families. We provide a list of bird species found within the harvested and unharvested blocks of the concession for the benefit of other researchers assessing the responses of Neotropical avifauna to disturbance, and to facilitate increased understanding of the diverse bird assemblages found within the lowland subtropical humid forests of Bolivia. 

scholarly journals Diversity and temporal variation of the bird community in paddy fields of Kadhiramangalam, Tamil Nadu, India

2019 ◽  
Vol 11 (10) ◽  
pp. 14279-14291
Author(s):  
Chaithra Shree Jayasimhan ◽  
Pramod Padmanabhan
Keyword(s):  
Species Composition ◽  
Community Composition ◽  
Tamil Nadu ◽  
Bird Species ◽  
Bird Community ◽  
Paddy Fields ◽  
Common Myna ◽  
Short Period ◽  
Community Data ◽  
Paddy Cultivation

Paddy, a major food crop of India, provides a variety of habitats in a short period of time and supports diverse organisms.  Paddy fields also harbour many birds with varying species composition across the different cultivation phases of paddy.  This study, conducted in the paddy fields of Kadhiramangalam, Tamil Nadu, India, recorded the bird community composition there during the various cultivation phases of paddy.  The bird community data was analysed and a total of 87 bird species were recorded from the study area belonging to 41 families and 13 orders.  The growth phase (PS 3) is the most diverse phase.  The bird composition showed a significant variation across the paddy cultivation phases with overall average dissimilarity of 71.41%.  The patterns shown by graphs of bird species composition across the paddy cultivation phases is based on guild, habitat usage and order overlap and elucidates that the change in bird community composition temporally can be attributed to the niche variability across the paddy cultivation phases.  The major species contributing to these changes observed are Black-headed Munia, Baya Weaver, Common Sandpiper, Barn Swallow, Common Myna, and Black Drongo in this region.   

scholarly journals Relative importance of the land-use composition and intensity for the bird community composition in anthropogenic landscapes

2017 ◽  
Vol 7 (24) ◽  
pp. 10513-10535 ◽  
Author(s):  
Vincent Pellissier ◽  
Anne Mimet ◽  
Colin Fontaine ◽  
Jens-Christian Svenning ◽  
Denis Couvet
Keyword(s):  
Land Use ◽  
Community Composition ◽  
Bird Community ◽  
Relative Importance ◽  
Anthropogenic Landscapes

scholarly journals Soil Enzyme Activity and Soil Nutrients Jointly Influence Post-Fire Habitat Models in Mixed-Conifer Forests of Yosemite National Park, USA

Fire ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 54
Author(s):  
Jelveh Tamjidi ◽  
James A. Lutz
Keyword(s):  
Environmental Factors ◽  
Soil Properties ◽  
Soil Nutrients ◽  
Environmental Variables ◽  
National Park ◽  
Basal Area ◽  
Yosemite National Park ◽  
Relative Importance ◽  
Species Assemblage ◽  
Spatial Factors

Disentangling the relative importance of habitat filtering and dispersal limitations at local scales (<1 km2) in shaping species composition remains an important question in community ecology. Previous studies have examined the relative importance of these mechanisms using topography and selected soil properties. We examined both topography and edaphic properties from 160 locations in the recently burned 25.6 ha Yosemite Forest Dynamics Plot (YFDP) in Yosemite National Park, California, USA. In addition to eight soil chemical properties, we included phosphatases and urease enzymes in a definition of habitat niches, primarily because of their rapid changes with fire (compared to soil nutrients) and also their role in ecosystem function. We applied environmental variables to the distributions of 11 species. More species–habitat associations were defined by soil properties (54.5%) than topographically-defined habitat (45.4%). We also examined the relative importance of spatial and environmental factors in species assemblage. Proportions explained by spatial and environmental factors differed among species and demographic metrics (stem abundance, basal area increment, mortality, and recruitment). Spatial factors explained more variation than environmental factors in stem abundance, mortality, and recruitment. The contributions of urease and acid phosphatase to habitat definition were significant for species abundance and basal area increment. These results emphasize that a more complete understanding of niche parameters is needed beyond simple topographic factors to explain species habitat preference. The stronger contribution of spatial factors suggests that dispersal limitation and unmeasured environmental variables have high explanatory power for species assemblage in this coniferous forest.

scholarly journals Distinctiveness, Use, and Value of Midwestern Oak Savannas and Woodlands as Avian Habitats

The Auk ◽  
2007 ◽  
Vol 124 (3) ◽  
pp. 969-985 ◽  
Author(s):  
Ralph Grundel ◽  
Noel B. Pavlovic
Keyword(s):  
Community Composition ◽  
Threatened Species ◽  
Habitat Type ◽  
Bird Species ◽  
Canopy Cover ◽  
Bird Community ◽  
Woody Vegetation ◽  
Oak Savannas ◽  
Vegetation Gradient ◽  
Forest Habitats

Abstract Oak savannas and woodlands historically covered millions of hectares in the midwestern United States but are rare today. We evaluated the ecological distinctiveness and conservation value of savannas and woodlands by examining bird distributions across a fire-maintained woody-vegetation gradient in northwest Indiana encompassing five habitats—open habitats with low canopy cover, savannas, woodlands, scrublands, and forests—during migration, breeding, and overwintering. Savannas and woodlands were significantly different in overall bird species composition from open and forest habitats but were often intermediate between open and forest in guild densities. Few bird species were consistently and highly concentrated in savannas or woodlands, and the Red-headed Woodpecker (Melanerpes erythrocephalus) was the only species significantly more abundant in savannas and woodlands than in open, scrub, and forest habitats. Fire frequency over a 15-year interval was a significant predictor of bird community composition and was positively related to species diversity, spring transient migrant density, and density of the most threatened species. Each habitat type had characteristics potentially important for avian conservation. Scrub had the highest density of transient migrants, which suggests it plays an important role as migration stopover habitat. More species were significantly concentrated in open or forest habitats than in the other habitats. Lack of species concentration and intermediate community composition suggested that birds experienced savannas and woodlands more as ecotones than as habitats distinct from forests or grasslands. However, this intermediate character can benefit conservation, as evidenced by savannas and woodlands having the highest density of the most threatened species along this woody-vegetation gradient. Características Únicas, Uso y Valor de las Sabanas y Bosques Abiertos de Roble del Oeste Central como Hábitats para las Aves

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