Distribution of the native earthworm fauna of the Perth metropolitan sector of the Swan Coastal Plain

2002 ◽  
Vol 8 (3) ◽  
pp. 196
Author(s):  
Ian Abbott ◽  
Allan Wills
Keyword(s):  
Coastal Plain ◽  
Native Species ◽  
Species Abundance ◽  
Common Species ◽  
Habitat Diversity ◽  
Remnant Vegetation ◽  
Invertebrate Diversity ◽  
Swan Coastal Plain ◽  
Species Abundances ◽  
Species Area

Assessment of areas suitable for inclusion in a comprehensive, adequate and representative (CAR) reserve system has been based primarily on distribution of original native vegetation and occurrence of vertebrates, particularly birds and mammals. However, reliable predictors of vertebrate and floristic diversity are not necessarily adequate predictors of invertebrate diversity. We sampled the earthworm fauna of the Perth metropolitan Swan Coastal Plain (SCP) to examine whether vegetation-based criteria are sufficient for identifying a conservation estate for native earthworms. Twenty-one native species were collected from 136 sample localities. All five previously described native species from the region and three native species previously collected but not formally described were again collected, while 13 previously uncollected species were found. Species abundances of native earthworms were uneven, in common with species-abundance relationships for many other invertebrate assemblages, with 10 singleton occurrences of species and few common species. Species diversity increased away from the coast across the sandy geomorphic units Quindalup, Spearwood and Bassendean. Our study did not resolve whether dlifferences in earthworm faunas reflect the gradient in soil qualities across these units, gradients in species-area effects, habitat diversity effects or a combination of these. Blocks of remnant vegetation identified in the Western Australian Government's Bush Forever plan as containing natural areas of regional conservation value are also likely to support at least one native earthworm species. However, many of the blocks of remnant vegetation so identified are not within the formal conservation estate. Two species identified in this survey fortuitously persist only in remnant vegetation patches not considered regionally significant. Actual regional diversity was estimated to be 38 native species, indicating many uncollected relatively rare species. Although earthworms are a low diversity group compared with other invertebrates, the localized distributions of most species indicate that the formal conservation estate does not provide adequate protection. Ongoing degradation of unprotected remnant vegetation will result in extinctions of localized invertebrate species.

scholarly journals A new method to analyze species abundances in space using generalized dimensions

2015 ◽  
Author(s):  
Leonardo A Saravia
Keyword(s):  
Species Abundance ◽  
Abundance Distribution ◽  
Community Patterns ◽  
Information Dimension ◽  
Generalized Dimension ◽  
Species Abundances ◽  
Species Abundance Distributions ◽  
Species Area ◽  
Generalized Dimensions ◽  
Relationship Of

Species-area relationships (SAR) and species abundance distributions (SAD) are among the most studied patterns in ecology, due to their application to both theoretical and conservation issues. One problem with these general patterns is that different theories can generate the same predictions, and for this reason they cannot be used to detect different mechanisms of community assembly. A solution is to search for more sensitive patterns, for example by extending the SAR to the whole species abundance distribution. A generalized dimension ($D_q$) approach has been proposed to study the scaling of SAD, but to date there has been no evaluation of the ability of this pattern to detect different mechanisms. An equivalent way to express SAD is the rank abundance distribution (RAD). Here I introduce a new way to study SAD scaling using a spatial version of RAD: the species-rank surface (SRS), which can be analyzed using $D_q$. Thus there is an old $D_q$ based on SAR ($D_q^{SAD}$), and a new one based on SRS ($D_q^{SRS}$). I perform spatial simulations to examine the relationship of $D_q$ with SAD, spatial patterns and number of species. Finally I compare the power of both $D_q$, SAD, SAR exponent, and the fractal information dimension to detect different community patterns using a continuum of hierarchical and neutral spatially explicit models. The SAD, $D_q^{SAD}$ and $D_q^{SRS}$ all had good performance in detecting models with contrasting mechanisms. $D_q^{SRS}$, however, had a better fit to data and allowed comparisons between hierarchical communities where the other methods failed. The SAR exponent and information dimension had low power and should not be used. SRS and $D_q^{SRS}$ could be interesting methods to study community or macroecological patterns.

scholarly journals Self–organized instability in complex ecosystems

2002 ◽  
Vol 357 (1421) ◽  
pp. 667-681 ◽  
Author(s):  
Ricard V. Solé ◽  
David Alonso ◽  
Alan McKane
Keyword(s):  
Rare Species ◽  
Scaling Law ◽  
Species Abundance ◽  
Field Studies ◽  
Species Number ◽  
Neotropical Forests ◽  
Species Abundances ◽  
Long Tails ◽  
Critical Boundary ◽  
Species Area

Why are some ecosystems so rich, yet contain so many rare species? High species diversity, together with rarity, is a general trend in neotropical forests and coral reefs. However, the origin of such diversity and the consequences of food web complexity in both species abundances and temporal fluctuations are not well understood. Several regularities are observed in complex, multispecies ecosystems that suggest that these ecologies might be organized close to points of instability. We explore, in greater depth, a recent stochastic model of population dynamics that is shown to reproduce: (i) the scaling law linking species number and connectivity; (ii) the observed distributions of species abundance reported from field studies (showing long tails and thus a predominance of rare species); (iii) the complex fluctuations displayed by natural communities (including chaotic dynamics); and (iv) the species–area relations displayed by rainforest plots. It is conjectured that the conflict between the natural tendency towards higher diversity due to immigration, and the ecosystem level constraints derived from an increasing number of links, leaves the system poised at a critical boundary separating stable from unstable communities, where large fluctuations are expected to occur. We suggest that the patterns displayed by species–rich communities, including rarity, would result from such a spontaneous tendency towards instability.

scholarly journals Freshwater cyclopoids and harpacticoids (Crustacea: Copepoda) from the Gnangara Mound region of Western Australia

Zootaxa ◽  
2009 ◽  
Vol 2029 (1) ◽  
pp. 1-70 ◽  
Author(s):  
DANNY TANG ◽  
BRENTON KNOTT
Keyword(s):  
Ground Water ◽  
Western Australia ◽  
Coastal Plain ◽  
National Park ◽  
South Australia ◽  
Common Species ◽  
Unconfined Aquifer ◽  
Swan Coastal Plain ◽  
Freshwater Copepods ◽  
First Time

The Gnangara Mound is a 2,200 km 2 unconfined aquifer located in the Swan Coastal Plain of Western Australia. This aquifer is one of the most important ground water resources for the Perth Region and supports a number of groundwaterdependent ecosystems, such as the springs of Ellen Brook and root mat communities of the Yanchep Caves. Although freshwater copepods have been documented previously from those caves and springs, their specific identity were hitherto unknown. The current work formally identifies copepod samples collected from 23 sites (12 cave, three bore, five spring and three surface water localities) within the Gnangara Mound region. Fifteen species were documented in this study: the cyclopoids Australoeucyclops sp., Eucyclops edytae sp. nov., Macrocyclops albidus (Jurine, 1820), Mesocyclops brooksi Pesce, De Laurentiis & Humphreys, 1996, Metacyclops arnaudi (G. O. Sars, 1908), Mixocyclops mortoni sp. nov., Paracyclops chiltoni (Thomson, 1882), Paracyclops intermedius sp. nov. and Tropocyclops confinis (Kiefer, 1930), and the harpacticoids Attheyella (Chappuisiella) hirsuta Chappuis, 1951, Australocamptus hamondi Karanovic, 2004, Elaphoidella bidens (Schmeil, 1894), Kinnecaris eberhardi (Karanovic, 2005), Nitocra lacustris pacifica Yeatman, 1983 and Paranitocrella bastiani gen. et sp. nov. Tropocyclops confinis is recorded from Australia for the first time and A. (Ch.) hirsuta and E. bidens are newly recorded for Western Australia. The only copepod taxa endemic to the Gnangara Mound region are E. edytae sp. nov. (occurs primarily in springs and rarely in the Yanchep National Park Caves) and P. bastiani gen. et sp. nov. (confined to the Yanchep National Park Caves containing tuart root mats). Paracyclops chiltoni was the most common species, whilst T. confinis and N. l. pacifica were rarely encountered. Metacyclops arnaudi was the only taxon absent from ground waters. The copepod fauna recorded in the caves and springs of the Gnangara Mound region are comparable, with respect to species richness, endemicity and the varying degrees of dependency on ground water, to those reported from similar habitats in South Australia and Western Australia. Restoring the root mats and maintaining permanent water flow within the Yanchep Caves, as well as minimising urban development near the Ellen Brook Springs, are essential to protect the copepod species, particularly the endemic P. bastiani gen. et sp. nov. and E. edytae sp. nov., inhabiting these unique ground water environments.

The zoogeographic significance of urban bushland remnants to reptiles in the Perth region, Western Australia

1994 ◽  
Vol 1 (2) ◽  
pp. 132 ◽  
Author(s):  
R. A. How ◽  
J. Dell
Keyword(s):  
Cluster Analysis ◽  
Coastal Plain ◽  
Significant Relationship ◽  
Urban Areas ◽  
Coastal Region ◽  
Swan Coastal Plain ◽  
Reptile Species ◽  
Species Area ◽  
Taxonomic Groups ◽  
Swan River

The 71 reptile species occurring in the Perth region make this area as diverse as any similar sized coastal region in Australia. Cluster analysis of the lizard assemblages of 17 bushland remnants in the region indicate that three main sub-regions can be identified; Darling Plateau and Scarp, Offshore Islands and Swan Coastal Plain. Within the Swan Coastal Plain the lizard and skink faunas of remnant bushlands on the same landform are more similar to one another than they are to those of adjacent landforms. The Swan River appears to be a distributional boundary for some species. Species-area relationships indicate a variety of responses amongst the different taxonomic groups of reptiles, with snakes being the most sensitive to loss of habitat. The isolated remnant bushlands of inner urban areas retain a variety of reptile species, but there is no significant relationship with remnant size. The implications of zoogeographic and area relationships to conservation are discussed.

scholarly journals A new method to analyze species abundances in space using generalized dimensions

2014 ◽  
Author(s):  
Leonardo A Saravia
Keyword(s):  
Species Abundance ◽  
Abundance Distribution ◽  
Community Patterns ◽  
Information Dimension ◽  
Spatially Explicit Models ◽  
Generalized Dimension ◽  
Species Abundances ◽  
Species Abundance Distributions ◽  
Species Area ◽  
Generalized Dimensions

Species-area relationships (SAR) and species abundance distributions (SAD) are among the most studied patterns in ecology, due to their application in both theoretical and conservation issues. One problem with these general patterns is that different theories can generate the same predictions, and for this reason they can not be used to detect different mechanisms. A solution for this is to search for more sensitive patterns. One possibility is to extend the SAR to the whole species abundance distribution. A generalized dimension (\(D_q\)) approach has been proposed to study the scaling of SAD, but there has been no evaluation of the ability of this pattern to detect different mechanisms. An equivalent way to express SAD is the rank abundance distribution (RAD). Here I introduce a new way to study scaling of SAD using a spatial version of RAD: the species-rank surface (SRS), which can be analyzed using \(D_q\). Thus there is an old \(D_q\) based on SAR (\(D_q^{SAD}\)), and a new one based on SRS (\(D_q^{SRS}\)). I perform spatial simulations to relate both \(D_q\) with SAD, spatial patterns and number of species. Finally I compare the power of both \(D_q\), SAD, SAR exponent, and the fractal information dimension to detect different community patterns using a continuum of hierarchical and neutral spatially explicit models. The SAD, \(D_q^{SAD}\) and \(D_q^{SRS}\) all had good performance in detecting models with contrasting mechanisms. \(D_q^{SRS}\) had a better fit to data and a strong ability to compare between hierarchical communities where the other methods failed. The SAR exponent and information dimension had low power and should not be used. SRS and \(D_q^{SRS}\) could be an interesting addition to study community or macroecological patterns.

scholarly journals A new method to analyze species abundances in space using generalized dimensions

2014 ◽  
Author(s):  
Leonardo A Saravia
Keyword(s):  
Species Abundance ◽  
Abundance Distribution ◽  
Community Patterns ◽  
Information Dimension ◽  
Spatially Explicit Models ◽  
Generalized Dimension ◽  
Species Abundances ◽  
Species Abundance Distributions ◽  
Species Area ◽  
Generalized Dimensions

Species-area relationships (SAR) and species abundance distributions (SAD) are among the most studied patterns in ecology, due to their application in both theoretical and conservation issues. One problem with these general patterns is that different theories can generate the same predictions, and for this reason they can not be used to detect different mechanisms. A solution for this is to search for more sensitive patterns. One possibility is to extend the SAR to the whole species abundance distribution. A generalized dimension ($D_q$) approach has been proposed to study the scaling of SAD, but there has been no evaluation of the ability of this pattern to detect different mechanisms. An equivalent way to express SAD is the rank abundance distribution (RAD). Here I introduce a new way to study scaling of SAD using a spatial version of RAD: the species-rank surface (SRS), which can be analyzed using $D_q$. Thus there is an old $D_q$ based on SAR ($D_q^{SAD}$), and a new one based on SRS ($D_q^{SRS}$). I perform spatial simulations to relate both $D_q$ with SAD, spatial patterns and number of species. Finally I compare the power of both $D_q$, SAD, SAR exponent, and the fractal information dimension to detect different community patterns using a continuum of hierarchical and neutral spatially explicit models. The SAD, $D_q^{SAD}$ and $D_q^{SRS}$ all had good performance in detecting models with contrasting mechanisms. $D_q^{SRS}$ had a better fit to data and a strong ability to compare between hierarchical communities where the other methods failed. The SAR exponent and information dimension had low power and should not be used. SRS and $D_q^{SRS}$ could be an interesting addition to study community or macroecological patterns.

scholarly journals A new method to analyze species abundances in space using generalized dimensions

2015 ◽  
Author(s):  
Leonardo A Saravia
Keyword(s):  
Species Abundance ◽  
Abundance Distribution ◽  
Community Patterns ◽  
Information Dimension ◽  
Generalized Dimension ◽  
Species Abundances ◽  
Species Abundance Distributions ◽  
Species Area ◽  
Generalized Dimensions ◽  
Relationship Of

Species-area relationships (SAR) and species abundance distributions (SAD) are among the most studied patterns in ecology, due to their application to both theoretical and conservation issues. One problem with these general patterns is that different theories can generate the same predictions, and for this reason they cannot be used to detect different mechanisms of community assembly. A solution is to search for more sensitive patterns, for example by extending the SAR to the whole species abundance distribution. A generalized dimension ($D_q$) approach has been proposed to study the scaling of SAD, but to date there has been no evaluation of the ability of this pattern to detect different mechanisms. An equivalent way to express SAD is the rank abundance distribution (RAD). Here I introduce a new way to study SAD scaling using a spatial version of RAD: the species-rank surface (SRS), which can be analyzed using $D_q$. Thus there is an old $D_q$ based on SAR ($D_q^{SAD}$), and a new one based on SRS ($D_q^{SRS}$). I perform spatial simulations to examine the relationship of $D_q$ with SAD, spatial patterns and number of species. Finally I compare the power of both $D_q$, SAD, SAR exponent, and the fractal information dimension to detect different community patterns using a continuum of hierarchical and neutral spatially explicit models. The SAD, $D_q^{SAD}$ and $D_q^{SRS}$ all had good performance in detecting models with contrasting mechanisms. $D_q^{SRS}$, however, had a better fit to data and allowed comparisons between hierarchical communities where the other methods failed. The SAR exponent and information dimension had low power and should not be used. SRS and $D_q^{SRS}$ could be interesting methods to study community or macroecological patterns.

scholarly journals A new method to analyze species abundances in space using generalized dimensions

2014 ◽  
Author(s):  
Leonardo A Saravia
Keyword(s):  
Species Abundance ◽  
Abundance Distribution ◽  
Community Patterns ◽  
Information Dimension ◽  
Spatially Explicit Models ◽  
Generalized Dimension ◽  
Species Abundances ◽  
Species Abundance Distributions ◽  
Species Area ◽  
Generalized Dimensions

Species-area relationships (SAR) and species abundance distributions (SAD) are among the most studied patterns in ecology, due to their application in both theoretical and conservation issues. One problem with these general patterns is that different theories can generate the same predictions, and for this reason they can not be used to detect different mechanisms. A solution for this is to search for more sensitive patterns. One possibility is to extend the SAR to the whole species abundance distribution. A generalized dimension (\(D_q\)) approach has been proposed to study the scaling of SAD, but there has been no evaluation of the ability of this pattern to detect different mechanisms. An equivalent way to express SAD is the rank abundance distribution (RAD). Here I introduce a new way to study scaling of SAD using a spatial version of RAD: the species-rank surface (SRS), which can be analyzed using \(D_q\). Thus there is an old \(D_q\) based on SAR (\(D_q^{SAD}\)), and a new one based on SRS (\(D_q^{SRS}\)). I perform spatial simulations to relate both \(D_q\) with SAD, spatial patterns and number of species. Finally I compare the power of both \(D_q\), SAD, SAR exponent, and the fractal information dimension to detect different community patterns using a continuum of hierarchical and neutral spatially explicit models. The SAD, \(D_q^{SAD}\) and \(D_q^{SRS}\) all had good performance in detecting models with contrasting mechanisms. \(D_q^{SRS}\) had a better fit to data and a strong ability to compare between hierarchical communities where the other methods failed. The SAR exponent and information dimension had low power and should not be used. SRS and \(D_q^{SRS}\) could be an interesting addition to study community or macroecological patterns.

scholarly journals Native Species Abundance Buffers Non-Native Plant Invasibility following Intermediate Forest Management Disturbances

2019 ◽  
Vol 65 (3) ◽  
pp. 336-343 ◽  
Author(s):  
Donald P Chance ◽  
Johannah R McCollum ◽  
Garrett M Street ◽  
Bronson K Strickland ◽  
Marcus A Lashley
Keyword(s):  
Species Richness ◽  
Loblolly Pine ◽  
Native Species ◽  
Biotic Resistance ◽  
Species Abundance ◽  
Data Sets ◽  
Native Plant ◽  
Species Abundances ◽  
Intermediate Disturbances ◽  
Native Species Richness

Abstract The biotic resistance hypothesis (BRH) was proposed to explain why intermediate disturbances lead to greater resistance to non-native invasions proposing communities that are more diverse provide greater resistance. However, several empirical data sets have rejected the BRH because native and non-native species richness often have a positive relation. We tested the BRH in a mature loblolly pine (Pinus taeda) forest with a gradient of disturbance intensities including canopy reduction, canopy reduction + fire, and canopy reduction + herbicide and fire. We analyzed data from the study using a combination of Pearson’s correlation and beta regressions. Using species richness, we too would reject BRH because of a positive correlation in species richness between native and non-native plants. However, native species abundance was greatest, and non-native species abundance was lowest following intermediate disturbances. Further, native and non-native species abundances were negatively correlated in a quadratic relation across disturbance intensities, suggesting that native species abundance, rather than richness, may be the mechanism of resistance to non-native invasions. We propose that native species abundance regulates resistance to non-native invasions and that intermediate disturbances provide the greatest resistance because they promote the greatest native species abundance.

scholarly journals A new method to analyze species abundances in space using generalized dimensions

2015 ◽  
Author(s):  
Leonardo A Saravia
Keyword(s):  
Species Abundance ◽  
Abundance Distribution ◽  
Community Patterns ◽  
Information Dimension ◽  
Spatially Explicit Models ◽  
Generalized Dimension ◽  
Species Abundances ◽  
Species Abundance Distributions ◽  
Species Area ◽  
Generalized Dimensions

Species-area relationships (SAR) and species abundance distributions (SAD) are among the most studied patterns in ecology, due to their application in both theoretical and conservation issues. One problem with these general patterns is that different theories can generate the same predictions, and for this reason they can not be used to detect different mechanisms. A solution for this is to search for more sensitive patterns. One possibility is to extend the SAR to the whole species abundance distribution. A generalized dimension (\(D_q\)) approach has been proposed to study the scaling of SAD, but there has been no evaluation of the ability of this pattern to detect different mechanisms. An equivalent way to express SAD is the rank abundance distribution (RAD). Here I introduce a new way to study scaling of SAD using a spatial version of RAD: the species-rank surface (SRS), which can be analyzed using \(D_q\). Thus there is an old \(D_q\) based on SAR (\(D_q^{SAD}\)), and a new one based on SRS (\(D_q^{SRS}\)). I perform spatial simulations to relate both \(D_q\) with SAD, spatial patterns and number of species. Finally I compare the power of both \(D_q\), SAD, SAR exponent, and the fractal information dimension to detect different community patterns using a continuum of hierarchical and neutral spatially explicit models. The SAD, \(D_q^{SAD}\) and \(D_q^{SRS}\) all had good performance in detecting models with contrasting mechanisms. \(D_q^{SRS}\) had a better fit to data and a strong ability to compare between hierarchical communities where the other methods failed. The SAR exponent and information dimension had low power and should not be used. SRS and \(D_q^{SRS}\) could be an interesting addition to study community or macroecological patterns.

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