Abundance Patterns and Community Attributes of Fishes Relative to Environmental Gradients

1987 ◽  
Vol 44 (S2) ◽  
pp. s198-s215 ◽  
Author(s):  
T. R. Marshall ◽  
P. A. Ryan
Keyword(s):  
Food Webs ◽  
Environmental Gradients ◽  
Species Abundance ◽  
Lake Area ◽  
Secchi Disk Transparency ◽  
Abundance Patterns ◽  
Morphoedaphic Index ◽  
Environmental Unpredictability ◽  
Polymictic Lakes ◽  
Canadian Boreal Forest

Seventy-five lakes of the Canadian boreal forest were examined for patterns of fish species abundance and community structure in relation to gradients of four environmental variables: (1) lake area, (2) mean depth, (3) Secchi disk transparency, and (4) morphoedaphic index (MEI). Mean depth appeared to exert the greatest control on the relative abundance of the species considered. The remaining variables influenced abundance in unique ways, although, as with mean depth, this influence was mainly a consequence of changes in thermal and nutrient regimes. An examination of lower trophic components indicated that these regimes appear to structure food webs, with distinctly different patterns in food webs occurring in dimictic and polymictic lakes. Major shifts in aquatic biota occur in the transition region between lake types. Lakes with these characteristics are at a lower successional state due to environmental unpredictability, as demonstrated by an increasing importance of r- over K-strategists.

Species abundance patterns of plants in Swedish semi-natural pastures

Ecography ◽  
1995 ◽  
Vol 18 (3) ◽  
pp. 310-317 ◽  
Author(s):  
Asa Eriksson ◽  
Ove Eriksson ◽  
Hans Berglund
Keyword(s):  
Species Abundance ◽  
Abundance Patterns

scholarly journals Remotely Sensed Variables of Ecosystem Functioning Support Robust Predictions of Abundance Patterns for Rare Species

2019 ◽  
Vol 11 (18) ◽  
pp. 2086 ◽  
Author(s):  
Salvador Arenas-Castro ◽  
Adrián Regos ◽  
João F. Gonçalves ◽  
Domingo Alcaraz-Segura ◽  
João Honrado
Keyword(s):  
Species Distribution ◽  
Ecosystem Functioning ◽  
Environmental Changes ◽  
Predictive Accuracy ◽  
Species Abundance ◽  
Habitats Directive ◽  
The European Union ◽  
Distribution Models ◽  
Essential Information ◽  
Abundance Patterns

Global environmental changes are affecting both the distribution and abundance of species at an unprecedented rate. To assess these effects, species distribution models (SDMs) have been greatly developed over the last decades, while species abundance models (SAMs) have generally received less attention even though these models provide essential information for conservation management. With population abundance defined as an essential biodiversity variable (EBV), SAMs could offer spatially explicit predictions of species abundance across space and time. Satellite-derived ecosystem functioning attributes (EFAs) are known to inform on processes controlling species distribution, but they have not been tested as predictors of species abundance. In this study, we assessed the usefulness of SAMs calibrated with EFAs (as process-related variables) to predict local abundance patterns for a rare and threatened species (the narrow Iberian endemic ‘Gerês lily’ Iris boissieri; protected under the European Union Habitats Directive), and to project inter-annual fluctuations of predicted abundance. We compared the predictive accuracy of SAMs calibrated with climate (CLI), topography (DEM), land cover (LCC), EFAs, and combinations of these. Models fitted only with EFAs explained the greatest variance in species abundance, compared to models based only on CLI, DEM, or LCC variables. The combination of EFAs and topography slightly increased model performance. Predictions of the inter-annual dynamics of species abundance were related to inter-annual fluctuations in climate, which holds important implications for tracking global change effects on species abundance. This study underlines the potential of EFAs as robust predictors of biodiversity change through population size trends. The combination of EFA-based SAMs and SDMs would provide an essential toolkit for species monitoring programs.

scholarly journals The emergent interactions that govern biodiversity change

2020 ◽  
Vol 117 (29) ◽  
pp. 17074-17083 ◽  
Author(s):  
James S. Clark ◽  
C. Lane Scher ◽  
Margaret Swift
Keyword(s):  
Species Interactions ◽  
Environmental Gradients ◽  
Local Population ◽  
Species Abundance ◽  
Community Change ◽  
Model Specification ◽  
Data Simulation ◽  
Breeding Bird ◽  
Probabilistic Uncertainty ◽  
Nonlinear Responses

Observational studies have not yet shown that environmental variables can explain pervasive nonlinear patterns of species abundance, because those patterns could result from (indirect) interactions with other species (e.g., competition), and models only estimate direct responses. The experiments that could extract these indirect effects at regional to continental scales are not feasible. Here, a biophysical approach quantifies environment– species interactions (ESI) that govern community change from field data. Just as species interactions depend on population abundances, so too do the effects of environment, as when drought is amplified by competition. By embedding dynamic ESI within framework that admits data gathered on different scales, we quantify responses that are induced indirectly through other species, including probabilistic uncertainty in parameters, model specification, and data. Simulation demonstrates that ESI are needed for accurate interpretation. Analysis demonstrates how nonlinear responses arise even when their direct responses to environment are linear. Applications to experimental lakes and the Breeding Bird Survey (BBS) yield contrasting estimates of ESI. In closed lakes, interactions involving phytoplankton and their zooplankton grazers play a large role. By contrast, ESI are weak in BBS, as expected where year-to-year movement degrades the link between local population growth and species interactions. In both cases, nonlinear responses to environmental gradients are induced by interactions between species. Stability analysis indicates stability in the closed-system lakes and instability in BBS. The probabilistic framework has direct application to conservation planning that must weigh risk assessments for entire habitats and communities against competing interests.

The structure of ground beetle assemblages (Coleoptera: Carabidae) at fig fruit falls (Moraceae) in a terra firme rain forest near Manaus (Brazil)

2001 ◽  
Vol 17 (4) ◽  
pp. 549-561 ◽  
Author(s):  
WILFRIED PAARMANN ◽  
JOACHIM ADIS ◽  
NIGEL STORK ◽  
BURKHARD GUTZMANN ◽  
PHILIPP STUMPE ◽  
...  
Keyword(s):  
Rain Forest ◽  
Ground Beetle ◽  
Species Abundance ◽  
Carabid Beetles ◽  
Terra Firme ◽  
Stepping Stones ◽  
Host Trees ◽  
Abundance Patterns ◽  
Beetle Assemblages ◽  
Abundant Genus

The carabid beetle assemblage found feeding on fig fruit falls at night was studied in a terra firme rain forest near Manaus (Amazonia) from July 1991 to August 1996. A total of 8926 carabid beetles were collected on 64 fruit falls from 10 fig species. The most abundant genus was Notiobia with eight species, N. pseudolimbipennis being the most abundant. The Notiobia species comprised 92% of all specimens collected and all feed on small fig seeds. Their species abundance patterns varied considerably between individual fruit falls and during the course of a single fruit fall. However, the species abundance patterns for all Notiobia at all observed fruit falls for each of the two commonest fig species (Ficus subapiculata, F. guianensis), as well as for fruit falls of the remaining fig species, were very similar. Through feeding and breeding experiments and observations of reproductive success by dissection of females, only two of the eight Notiobia species were found to be specialized fig seed feeders, being able to reproduce only on fig fruit falls. The remaining six species of this genus use fig fruit falls as alternate hosts or ‘stepping stones’ between fruit falls of their host trees, which are widely separated both in time and space.

Empirical Models for Zoobenthic Biomass in Lakes

1987 ◽  
Vol 44 (5) ◽  
pp. 990-1001 ◽  
Author(s):  
Joseph B. Rasmussen ◽  
Jacob Kalff
Keyword(s):  
Littoral Zone ◽  
Chlorophyll Concentration ◽  
Empirical Models ◽  
Phosphorus Concentration ◽  
Lake Area ◽  
Total Phosphorus Concentration ◽  
Secchi Disk Transparency ◽  
Littoral Zones ◽  
Explained Variance ◽  
Local Variability

Estimates of macrozoobenthos from the literature were regressed against a series of limnological variables to yield empirical models for zoobenthic biomass in the profundal, sublittoral, and littoral zones of lakes. Variables indicative of phytoplankton biomass (chlorophyll concentration, total phosphorus concentration, and Secchi disk transparency) explained between 14 and 57% of the variance of zoobenthic biomass ((g/m2)0.1). Other factors such as humic colour, morphometry (slope, mean depth, ratio of mean to maximum depth, and lake area), and mean annual air temperature substantially increased the amount of explained variance. In the profundal and sublittoral zones, the best models explain 70% of the variance in zoobenthic biomass. Littoral zone models explained less than 50%, and this deficiency was attributed to sampling difficulties and to high local variability of slope and wave exposure in the littoral zone.

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