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

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.

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3448
Author(s):  
Seid Tiku Mereta ◽  
Pieter Lemmens ◽  
Luc De Meester ◽  
Peter L. M. Goethals ◽  
Pieter Boets

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.


2005 ◽  
Vol 65 (4) ◽  
pp. 683-695 ◽  
Author(s):  
R. Cintra ◽  
T. M. Sanaiotti

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.


2003 ◽  
Vol 13 (3) ◽  
pp. 175-187 ◽  
Author(s):  
Michelle H. Reynolds ◽  
Richard J. Camp ◽  
Bonnie M. B. Nielson ◽  
James D. Jacobi

We evaluated the abundance and distribution of low-elevation forest birds on windward Hawai'i Island during August 1993-February 1994, and present evidence of changes in the species composition of the forest bird community since 1979. Endemic Hawaiian birds occurred in native-dominated forests as low as 120 m elevation. Non-native species were detected at all survey locations. We observed non-native Saffron Finch Sicalis flaveola, previously unrecorded in Puna. Variable circular plot surveys of Kahauale'a Natural Area Reserve indicated the disappearance of two native species ('I'iwi Vestiaria coccinea and 'O'u Psittitostra psittacea), and two non-native additions (Red-billed Leiothrix Leiothrix lutea and Kalij Pheasant Lophura leucomelana) to the study area since the Hawai'i Forest Bird Survey conducted in 1979. We present evidence that native 'Elepaio Chasiempsis sandwichensis has experienced a decrease in population density and an elevational range contraction since 1979. Surveys indicate Puna's forest bird community has had increasing aliens and declining native species since 1979. The persistence of some native bird species within the range of avian disease vectors such as Culex quinquefasciatus in forests below 1,000 m elevation presents an important enigma that requires additional study.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Karen Dyson

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.


Check List ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 43 ◽  
Author(s):  
Adam Felton ◽  
Bennett A. Hennessey ◽  
Annika M. Felton ◽  
David B. Lindenmayer

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. 


2019 ◽  
Vol 11 (10) ◽  
pp. 14279-14291
Author(s):  
Chaithra Shree Jayasimhan ◽  
Pramod Padmanabhan

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.   


2016 ◽  
Vol 64 (5) ◽  
pp. 312
Author(s):  
Peter Smith ◽  
Judy Smith

We investigated bird habitat relationships in extensive eucalypt forest in the Blue Mountains, New South Wales, in 1986–87, assessing the importance of fire regime variables compared with other habitat variables. Our study sites encompassed a wide range of postfire ages, fire frequencies and fire severity, but we found no major bird community differences corresponding to differences in fire regime. The more common forest bird species appeared well adapted to fire regime variation in the 1980s. Tree canopy height was a far greater influence, with more species and more birds in taller forests (interpreted as a result of higher soil fertility leading to higher productivity of bird foods and greater structural complexity in taller forests). Other trends were fewer birds where there was a rainforest understorey under the eucalypts (reflecting the general scarcity of rainforest birds in the Blue Mountains), and more birds where nectar-rich flowers were more abundant (reflecting the abundance of nectarivorous birds in the Blue Mountains, especially over winter). The climate has changed since the 1980s and fires threaten to become much more severe, extensive and frequent. How these changes will impact on forest birds, and what management responses are required, is a critical area for further study.


The Auk ◽  
2007 ◽  
Vol 124 (3) ◽  
pp. 969-985 ◽  
Author(s):  
Ralph Grundel ◽  
Noel B. Pavlovic

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


2014 ◽  
Vol 281 (1795) ◽  
pp. 20141742 ◽  
Author(s):  
Sadia E. Ahmed ◽  
Alexander C. Lees ◽  
Nárgila G. Moura ◽  
Toby A. Gardner ◽  
Jos Barlow ◽  
...  

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called ‘roadless volume (RV)’ at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation.


Data ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 27
Author(s):  
Hyo-Ryeon Kim ◽  
Jae-Hyun Lim ◽  
Ju-Hyoung Kim ◽  
Il-Nam Kim

Marine bacteria, which are known as key drivers for marine biogeochemical cycles and Earth’s climate system, are mainly responsible for the decomposition of organic matter and production of climate-relevant gases (i.e., CO₂, N₂O, and CH₄). However, research is still required to fully understand the correlation between environmental variables and bacteria community composition. Marine bacteria living in the Marian Cove, where the inflow of freshwater has been rapidly increasing due to substantial glacial retreat, must be undergoing significant environmental changes. During the summer of 2018, we conducted a hydrographic survey to collect environmental variables and bacterial community composition data at three different layers (i.e., the seawater surface, middle, and bottom layers) from 15 stations. Of all the bacterial data, 17 different phylum level bacteria and 21 different class level bacteria were found and Proteobacteria occupy 50.3% at phylum level following Bacteroidetes. Gammaproteobacteria and Alphaproteobacteria, which belong to Proteobacteria, are the highest proportion at the class level. Gammaproteobacteria showed the highest relative abundance in all three seawater layers. The collection of environmental variables and bacterial composition data contributes to improving our understanding of the significant relationships between marine Antarctic regions and marine bacteria that lives in the Antarctic.


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