Temporal and spatial variation in the abundance of fish associated with the seagrass Posidonia australis in South-eastern Australia

1993 ◽  
Vol 44 (6) ◽  
pp. 881 ◽  
Author(s):  
DJ Ferrell ◽  
SE McNeill ◽  
DG Worthington ◽  
JD Bell
Keyword(s):  
Spatial Variation ◽  
Spatial Scales ◽  
Seagrass Beds ◽  
Beam Trawl ◽  
Management Decisions ◽  
Temporal And Spatial Variation ◽  
South Eastern ◽  
Eastern Australia ◽  
Temporal And Spatial ◽  
South Eastern Australia

A beam trawl was used to sample fish associated with the seagrass Posidonia australis between September 1988 and June 1990. We describe variation in abundance of fish at two spatial scales: among three seagrass beds 1-10 km apart within each of three estuaries, and among the estuaries separated by at least 100 km. Most species had significant differences in abundance among sites and estuaries that changed through time. However, many species also had consistent patterns in abundance among sites and among estuaries. For example, there were large and consistent differences in the abundance of many species among the three estuaries. Widespread changes in abundance (ie: changes that took place at all sites within an estuary or in most estuaries) were not common. The two spatial scales used in this study are also logical scales for management of seagrass habitats. The consistent differences in abundance of some fish found at both spatial scales will complicate management decisions.

scholarly journals Patterns of demography for rocky-shore, intertidal invertebrates approaching their geographical range limits: tests of the abundant-centre hypothesis in south-eastern Australia

2010 ◽  
Vol 61 (11) ◽  
pp. 1243 ◽  
Author(s):  
Eszter Z. Hidas ◽  
David J. Ayre ◽  
Todd E. Minchinton
Keyword(s):  
Rocky Shore ◽  
Spatial Scales ◽  
Range Limits ◽  
Range Limit ◽  
Frequency Distributions ◽  
South Eastern ◽  
Size Frequency ◽  
Eastern Australia ◽  
Intertidal Invertebrates ◽  
South Eastern Australia

The abundant-centre hypothesis predicts that species' abundances peak at the centre of their geographical ranges and decline gradually towards their range limits. We tested predictions of this hypothesis for three rocky-shore, intertidal invertebrates with planktonic larvae (the whelk, Morula marginalba, the snail, Afrolittorina pyramidalis, and the barnacle, Tesseropora rosea) by quantifying their patterns of abundance and size, and inferring pulses of recruitment from size-frequency distributions, at multiple spatial scales spanning a 600-km region in south-eastern Australia and encompassing roughly the southern third of their geographical ranges. At the regional scale, abundances for all species were, as predicted, dramatically lower at their range limits. This decline was not gradual, however, because there were large variations in abundance at smaller spatial scales, and abrupt declines at the south-eastern corner of Australia. Size did not change towards the range limit for any species, but size-frequency distributions suggested a decline in the frequency of recruitment events at the range limit for T. rosea. We conclude that the abundant-centre hypothesis is not an appropriate model for abundance distributions of benthic marine invertebrates with planktonic larvae, because of the vagaries of dispersal and recruitment interacting with complex current patterns along non-uniform coastlines.

Fire exclusion and soil texture interact to influence temperate grassland flora in south-eastern Australia

2016 ◽  
Vol 64 (5) ◽  
pp. 417 ◽  
Author(s):  
Claire Moxham ◽  
Josh Dorrough ◽  
Mick Bramwell ◽  
Brad J. Farmilo
Keyword(s):  
Soil Texture ◽  
Spatial Scales ◽  
Temperate Grassland ◽  
Management Tool ◽  
Native Plant ◽  
Temperate Grasslands ◽  
South Eastern ◽  
Eastern Australia ◽  
Fire Exclusion ◽  
South Eastern Australia

Fire has a major influence on the structure and composition of temperate grasslands and woodlands. We investigated whether the impacts of fire exclusion on a temperate grassland plant community varied according to the scale of investigation and soil texture. Ten sites with known fire histories were selected along a soil texture gradient in south-eastern Australia. Floristics and ground layer attributes were investigated at small (0.25 m2) and large (100 m2) spatial scales in regularly burnt and unburnt grasslands. Fire exclusion over a 10 year period led to declines in native species diversity, richness and cover at both spatial scales and in most cases effects were consistent regardless of soil texture. However, the richness of native plant species at small scales and the cover of native plants at large scales were most negatively influenced by fire exclusion on fine textured soils. Conversely, at large scales, exotic plant richness and cover were only weakly increased by fire exclusion. Responses of eight common species were modelled and in seven of these, fire exclusion was a strong predictor of occurrence, although both positive and negative responses were observed. These results reiterate the importance of frequent fire as a management tool in temperate grasslands, but also shed light on how sites may require specific fire management regimes depending on the underlying soil texture.

Modelling the abundance of wildlife using field surveys and GIS: non-native sambar deer (Cervus unicolor) in the Yarra Ranges, south-eastern Australia

2009 ◽  
Vol 36 (3) ◽  
pp. 231 ◽  
Author(s):  
David M. Forsyth ◽  
Steve R. McLeod ◽  
Michael P. Scroggie ◽  
Matthew D. White
Keyword(s):  
Predictive Model ◽  
Spatial Scales ◽  
Strong Support ◽  
Geographic Information ◽  
Field Surveys ◽  
Faecal Pellets ◽  
South Eastern ◽  
Eastern Australia ◽  
Sambar Deer ◽  
South Eastern Australia

Combining abundance data collected in designed field surveys with biophysical data derived from geographic information systems is a powerful way to investigate predictors of spatial variation in the abundance of wildlife. We used such an approach to evaluate hypotheses about factors influencing the abundance of sambar deer (Cervus unicolour Kerr, 1792), a large non-native herbivore, in south-eastern Australia. We developed a spatial model for the abundance of sambar deer faecal pellets in a 3650-ha area in the Upper Yarra Ranges, Victoria. We counted the number of sambar deer faecal pellets along 100 randomly located transects and used a geographic information system to estimate biophysical variables around each transect. We formulated our hypotheses about how those variables might affect the abundance of sambar deer pellets into 22 candidate models and used the deviance information criterion to identify the ‘best’ model(s). Because five models had strong support we used model averaging to generate a predictive model. The three variables included in the predictive model were aspect (abundance of pellets declined with increasing ‘northerliness’ and increased with increasing ‘easterliness’), distance to water and elevation; the latter two variables were positively correlated and had a negative effect on the abundance of pellets. In contrast to previous models of sambar deer abundance in south-eastern Australia, our spatial predictions of the abundance of faecal pellets can be easily tested and updated. Our approach would be useful for modelling the abundances of other wildlife species at a range of spatial scales.

scholarly journals Phylogenetic paleoecology: macroecology within an evolutionary framework

Paleobiology ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 171-177
Author(s):  
James C. Lamsdell ◽  
Curtis R. Congreve
Keyword(s):  
Species Diversity ◽  
Spatial Variation ◽  
Geographic Distribution ◽  
Evolutionary Biology ◽  
Phylogenetic Signal ◽  
Evolutionary Rates ◽  
The Other ◽  
Ecological Data ◽  
Temporal And Spatial Variation ◽  
Temporal And Spatial

The burgeoning field of phylogenetic paleoecology (Lamsdell et al. 2017) represents a synthesis of the related but differently focused fields of macroecology (Brown 1995) and macroevolution (Stanley 1975). Through a combination of the data and methods of both disciplines, phylogenetic paleoecology leverages phylogenetic theory and quantitative paleoecology to explain the temporal and spatial variation in species diversity, distribution, and disparity. Phylogenetic paleoecology is ideally situated to elucidate many fundamental issues in evolutionary biology, including the generation of new phenotypes and occupation of previously unexploited environments; the nature of relationships among character change, ecology, and evolutionary rates; determinants of the geographic distribution of species and clades; and the underlying phylogenetic signal of ecological selectivity in extinctions and radiations. This is because phylogenetic paleoecology explicitly recognizes and incorporates the quasi-independent nature of evolutionary and ecological data as expressed in the dual biological hierarchies (Eldredge and Salthe 1984; Congreve et al. 2018; Fig. 1), incorporating both as covarying factors rather than focusing on one and treating the other as error within the dataset.

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