scholarly journals Effects of environmental variation on the composition and dynamics of an arid-adapted Australian bird community

2015 ◽  
Vol 21 (1) ◽  
pp. 74 ◽  
Author(s):  
Judy E. Smith
Keyword(s):  
Species Richness ◽  
Temporal Variability ◽  
Environmental Variability ◽  
Arid Zone ◽  
Climatic Variability ◽  
Bird Community ◽  
Bird Communities ◽  
Individual Species ◽  
Spatial And Temporal Variability ◽  
Severe Drought

Environmental variables influence the dynamics of bird communities. Australian arid-adapted bird communities must cope with particularly high levels of spatial and temporal variability, including inevitable but unpredictable periods of drought. Over four years, which included a severe drought and a period of above-average rainfall, I quantified the responses of a bird community in arid north-western New South Wales to regular seasonal and irregular climatic variation, especially rainfall, as well as spatial variation. I found pronounced changes in the abundance and composition of the avifauna that related to drought and, to a lesser extent, seasonal variability. Overall bird abundance and species richness declined during the drought but the magnitude and direction of population fluctuations of resident, nomadic and migratory species, different feeding groups, and individual species were not consistent. Avian densities and species richness in the study area were higher in mesic habitats associated with drainage lines than in run-off areas. The study demonstrated the importance of local habitat heterogeneity. The asynchronous species responses to a fluctuating environment indicated that drought is likely to have a differential effect on resources and that individual species respond differently to environmental variability. Effective land management and conservation of Australian arid-adapted bird communities requires an understanding of their spatial and temporal variability and dynamics at both local and regional level. A proper understanding of the variability and dynamics of the avifauna is especially important as climate change is predicted to exacerbate the climatic variability and unpredictability of the arid zone in future years.

scholarly journals Impact of climate change on the phytoplankton community of the Aglou-Sidi Ifni coastline (Moroccan Atlantic coast)

2020 ◽  
Vol 183 ◽  
pp. 01004
Author(s):  
El mahjoub Gallouli ◽  
Hassan Oulad Ali ◽  
Ahmed Aamiri
Keyword(s):  
Temporal Variability ◽  
Phytoplankton Community ◽  
Atlantic Coast ◽  
Physicochemical Characteristics ◽  
Spatial And Temporal Variability ◽  
Severe Drought ◽  
Phytoplankton Composition ◽  
Annual Cycles ◽  
Objective Monitoring ◽  
Climatic Hazards

The objective of this study is to understand the evolution of the typologies (physicochemical and phytoplankton) in Aglou-Sidi Ifni coastline according to hydrometeorological and climatic hazards. To achieve this objective, monitoring of the phytoplankton community and water physicochemical parameters was conducted at three stations along this coastline and during the winter and fall seasons of two different annual cycles (2014-2016). The first cycle experienced heavy flooding while the second cycle experienced severe drought. This study revealed spatial and temporal variability in phytoplankton composition and the relative abundance of its major groups. Temporal variability may be due to changes in the physicochemical characteristics of water masses as a function of continental inputs and wave intensity, which differ from cycle to cycle and season to another. Whereas the spatial variability would be due to the modification of these physicochemical characteristics from one station to another under the influence of the morphology of the coast in this zone, which curves westwards and carries Cape Aglou at its northern end, thus making the station of Sidi Ifni more exposed to currents than the other two stations which are somewhat sheltered.

Managing arid zone natural resources in Australia for spatial and temporal variability - an approach from first principles

2008 ◽  
Vol 30 (1) ◽  
pp. 15 ◽  
Author(s):  
Mark Stafford Smith ◽  
Ryan R. J. McAllister
Keyword(s):  
Resource Management ◽  
Natural Resource Management ◽  
Natural Resource ◽  
First Principles ◽  
Regional Integration ◽  
Arid Zone ◽  
Individual Species ◽  
Spatial And Temporal Variability ◽  
Systematic Analysis ◽  
The Difference

Outback Australia is characterised by variability in its resource drivers, particularly and most fundamentally, rainfall. Its biota has adapted to cope with this variability. The key strategies taken by desert organisms (and their weaknesses) help to identify the likely impacts of natural resource management by pastoralists and others, and potential remedies for these impacts. The key strategies can be summarised as five individual species’ responses (ephemerals, in-situ persistents, refuging persistents, nomads and exploiters), plus four key emergent modes of organisation involving multiple species that contribute to species diversity (facilitation, self-organising communities, asynchronous and micro-allopatric co-existence). A key feature of the difference between the strategies is the form of a reserve, whether roots and social networks for Persistents, or propagules or movement networks for Ephemerals and Nomads. With temporally and spatially varying drivers of soil moisture inputs, many of these strategies and their variants can co-exist. While these basic strategies are well known, a systematic analysis from first principles helps to generalise our understanding of likely impacts of management, if this changes the pattern of variability or interrupts the process of allocation to reserves. Nine resulting ‘weak points’ are identified in the system, and the implications of these are discussed for natural resource management and policy aimed at production or conservation locally, or the regional integration of the two.

scholarly journals Consistency in bird community assembly over medium-term along rural-urban gradients in Argentina

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lucas M. Leveau
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Rural Areas ◽  
Urban Areas ◽  
Environmental Filtering ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Assembly Rules ◽  
Urban Habitats

Abstract Background The analysis of bird community assembly rules is fundamental to understand which mechanisms determine the composition of bird species in urban areas. However, the long-term variation of community assembly rules has not been analyzed yet. The objectives of this study are (1) to analyze the variation of community assembly rules along rural-urban gradients of three cities in central Argentina and (2) to compare the patterns of community assembly between two periods separated by 6 years. Bird surveys were performed along transects in urban, suburban, and rural habitats during 2011 and 2017. Departures from null models that took into account differences in species richness (standardized effect size, SES) were calculated for functional and phylogenetic diversities. Results A total of 57 species were recorded. Bird species richness was higher in suburban than in urban and rural habitats. SES of functional diversity increased over the years and was significantly lower in urban habitats than in rural habitats, showing a pattern of functional clustering in the most urbanized areas and functional randomness in rural ones. Phylogenetic diversity was higher in both suburban and urban habitats than rural ones, and the phylogenetic clustering in rural bird assemblages changed to randomness in suburban and urban habitats. Conclusions Bird communities in urban habitats were phylogenetically random and functionally clustered, evidencing environmental filtering by urbanization. In contrast, bird communities in rural areas tended to be phylogenetically clustered, evidencing that certain clades are adapted to rural areas. The processes structuring bird communities along rural-urban gradients were consistent between the 2 years compared.

Spatial and temporal variability of water salinity in an ephemeral, arid-zone river, central Australia

2005 ◽  
Vol 19 (16) ◽  
pp. 3147-3166 ◽  
Author(s):  
Justin F. Costelloe ◽  
Rodger B. Grayson ◽  
Thomas A. McMahon ◽  
Robert M. Argent
Keyword(s):  
Temporal Variability ◽  
Arid Zone ◽  
Water Salinity ◽  
Spatial And Temporal Variability ◽  
Central Australia

scholarly journals Neotropical Forest Bird Communities: A Comparison of Species Richness and Composition at Local and Regional Scales

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 237-255 ◽  
Author(s):  
John G. Blake
Keyword(s):  
Species Richness ◽  
Spatial Scales ◽  
Geographic Distance ◽  
Bird Communities ◽  
Individual Species ◽  
Lowland Forest ◽  
Forest Bird ◽  
Neotropical Forest ◽  
Region I ◽  
The Family

Abstract Species richness and composition of Neotropical forest bird communities vary spatially at both large and small scales, but previous comparisons based on 100 ha plots have not replicated plots within a region. I sampled birds in two 100 ha plots in lowland forest of eastern Ecuador to better understand how species richness and composition vary over smaller spatial scales. Birds were sampled in February and April of 2002–2005 (only in February in 2005). Plots were approximately 1.5 km apart in predominantly terra firme forest. A total of 319 species (285 and 281 per plot) from 43 families were represented in ~16 000 detections per plot; number of species and detections per sample averaged approximately 185 and 2300, respectively. Numbers of species and detections per family were strikingly similar in the two plots, but numbers of detections of individual species often differed, likely in response to differences in habitat between the two plots. Species richness and composition were similar in many respects to comparable data from Ecuador, Peru, and French Guiana, but differed from those of Panama. Differences were most pronounced at the species level, less at the genus level, and least when comparisons were based on families. Differences among sites in South America were correlated with geographic distance at the species and genus levels, but not at the family level. Results illustrate the value of replicated plots within a region for understanding how species richness and composition can vary at small spatial scales, and highlight the importance of beta diversity for determining overall patterns of regional diversity.

The effect of fire on birds of mulga woodland in arid central Australia

2010 ◽  
Vol 19 (7) ◽  
pp. 949 ◽  
Author(s):  
Adam J. Leavesley ◽  
Geoffrey J. Cary ◽  
Glenn P. Edwards ◽  
A. Malcolm Gill
Keyword(s):  
Vegetation Structure ◽  
National Park ◽  
Arid Zone ◽  
Canopy Cover ◽  
Bird Community ◽  
Bird Communities ◽  
Time Since Fire ◽  
Central Australia ◽  
Acacia Aneura

The principal ecosystem driver in arid Australia is unpredictable rainfall, but it is hypothesised that fire also plays an important role in determining the distribution of animals. We investigated the effect of fire on birds in mulga (Acacia aneura) woodland in the central Australian arid zone. The study was conducted at Uluru–Kata Tjuta National Park using 63 sites classified into one of three time-since-fire classes: burnt 2002; burnt 1976; and long-unburnt. Birds were sampled in the winter and spring of 2005 and 2006 and vegetation structure was measured at all sites. Vegetation structure varied with time-since-fire. The burnt 2002 treatment was an early seral stage of mulga woodland and effectively a grassland. The burnt 1976 and long-unburnt treatments were both woodland, but the long-unburnt treatment had greater canopy cover and height. The bird community in the burnt 2002 treatment was characterised by granivores, whereas that in the burnt 1976 and long-unburnt treatments was characterised by foliar insectivores. All species showed monotonic responses to time-since-fire (i.e. none were at significantly highest density in the burnt 1976 treatment). Fire in mulga woodland changed the vegetation structure and consequently also changed the composition of the bird communities.

Bird communities and climate change

2019 ◽  
pp. 221-235
Author(s):  
Lluís Brotons ◽  
Sergi Herrando ◽  
Frédéric Jiguet ◽  
Aleksi Lehikoinen
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Spatial Scales ◽  
Climatic Variability ◽  
Global Environmental Change ◽  
Habitat Type ◽  
Bird Community ◽  
Bird Communities ◽  
Global Changes ◽  
Impacts Of Climate Change

Climate variability drives many aspects of the ecology of species directly or indirectly through changes in habitat type and structure, and thus long-term climatic variability has been thought to be the key determinant of community structure and change at large spatial scales. We review potential and reported impacts of climate change on shifts in bird community structure and composition. Bird communities are expected to change structure and composition, but observed changes appear generally slower than expected from temperature changes. However, we still lack a better understanding of regional differences in bird community responses to the different components of climate change and the explicit integration of climate with other global changes such as land uses, pollution, and invasive species. Finally, we propose a conceptual framework to guide our capability of understanding models and anticipate impacts of climate change on bird communities in a context of general and global environmental change.

scholarly journals Longleaf Pine Restoration: Implications for Landscape-Level Effects on Bird Communities in the Lower Gulf Coastal Plain

2003 ◽  
Vol 27 (2) ◽  
pp. 107-121 ◽  
Author(s):  
James W. Tucker ◽  
Geoffrey E. Hill ◽  
Nicholas R. Holler
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Longleaf Pine ◽  
Bird Species ◽  
Pinus Palustris ◽  
Bird Communities ◽  
Selective Logging ◽  
Neotropical Migrants ◽  
Individual Species ◽  
Riparian Habitats

Abstract The longleaf pine (Pinus palustris) ecosystem of the southeastern United States is among the most heavily degraded of all ecosystems. Less than 1% of the original longleaf pine forests remain as old-growth stands. Eglin Air Force Base (Eglin) in northwest Florida contains the largest remaining extent of longleaf pine, but much of this habitat has been degraded through fire suppression, selective logging, and planting off-site species of pines. We examined the distribution of bird species among habitats during spring and fall 1994–1995 to assess the influence of large-scale habitat restoration on bird communities across the landscape. During both spring and fall, species richness and relative abundance of neotropical migrants were greatest in oak hammocks and riparian habitats. During spring, the abundance of resident species was greatest in barrier island scrub and flatwoods, but species richness of residents also was high in oak hammocks. During fall, both species richness and abundance of residents were greatest in oak hammocks and flatwoods. Analyses of abundance for individual species (both neotropical migrants and residents) suggested that each habitat examined was important for ≥1 species. An analysis examining the importance of habitats for conservation found that oak hammocks and riparian habitats were important for species of high management concern, but burned sandhills along with oak hammocks and riparian habitats were very important for species of the greatest management concern. Our results suggest that habitat modifications resulting from restoration of the longleaf pine ecosystem will benefit many species of management concern. Bird species negatively affected by habitat modifications for longleaf pine restoration were abundant in other habitats. South. J. Appl. For. 27(2):107–121.

Sign in / Sign up

Export Citation Format

Share Document