Body Size Abundance Research Articles

PREDICTING PATTERNS OF MAMMALIAN SPECIES DIVERSITY FROM A PROCESS-BASED SIMULATION MODEL

Large-scale ecological patterns emerge from multiple biological processes that interact on several scales and are affected by the heterogeneity of the environment. I use a landscape simulation model to explore and analyze how interactions among various ecological processes affect patterns of mammalian species diversity according to body size. The model incorporates ecological realism by using mammalian allometric relationships with realistic values taken from field data. It uses energy as a common currency to model and compare how species of different sizes use their environment. Components of the model include landscape, habitat, patch, community, species, and population. Processes include continuous-time population growth, saturation effect, species-habitat matching, demographic stochasticity (local-scale), dispersal, and catastrophic stochasticity (landscape-scale). I simulated a 16-patch landscape, with each patch having a unique habitat, and a 10-species pool in which species differ only in body size. Summed over the landscape, a log-normal relationship between body size and species abundance emerges. Additionally, geographic range increases nonlinearly with the log of body size. These patterns are qualitatively consistent with patterns of mammalian species diversity observed in natural systems, suggesting that they can emerge from scaling of habitat use with body size. I also simulated a simple 4-patch landscape, with each patch having a unique habitat, and a 26-species pool to draw from in which species differ only in body size. The results show that interspecific competition by itself reduces species diversity in each habitat and in the entire landscape. Stochasticity depresses mean population sizes but opens opportunities for species to avoid competitive exclusion. It also allows different habitats to have different communities that are characterized by the consequences of which large species become locally extinct at random. Demographic and catastrophic stochasticities differ, however, in their characteristic effects on species diversity. These characteristic effects can be used as fingerprints to identify processes acting in nature. Dispersing individuals move between habitats and reestablish the local populations of their species. Overall, the model provides us with predictions of how process-interactions in heterogeneous landscape may affect species composition and community structure.

Growth response of pikeperch larvae in relation to body size and zooplankton abundance

Growth response of pikeperch larvae in relation to body size and zooplankton abundance

Phylogeny and the Relationship Between Body Size and Abundance in Bird Communities

1. Within local bird communities, relationships between body size and abundance across the subtaxa within lower-level taxa (such as species within genera) are no more likely to be positive than those across the subtaxa in higher-level taxa (such as suborders within orders). 2. The species within tribes of birds which have no close relatives in the world tend to show positive relationships between body size and population abundance. However, the relatedness of the tribe to others in its community is not a significant predictor of the sign of the body size-abundance pattern. 3. The date at which the species last shared a common ancestor is a better predictor of the size-abundance pattern than is the relatedness of a tribe to other birds in the world

The relationship between body size and population size in bromeliad tank faunas

Relationships between body size and abundance in collections of animals from the tanks of 73 bromeliads belonging to five species were analysed. Unlike data in previously published stuthes on this relationship, these collections of species are not taxonomically restricted and represent complete communities over the macroscopic range of organisms. There is no overall tendency for there to be a positive or negative relationship between population abundance and body size of morphospecies. We can find no evidence that body size-abundance patterns are triangular in complete communities. However, there is weak evidence that the relationship in the aquatic subsets of those communities may have some underlying triangularity, with medium-sized species having the largest populations.

The relationship between body size and population size in bromeliad tank faunas

Relationships between body size and abundance in collections of animals from the tanks of 73 bromeliads belonging to five species were analysed. Unlike data in previously published studies on this relationship, these collections of species are not taxonomically restricted and represent complete communities over the macroscopic range of organisms. There is no overall tendency for there to be a positive or negative relationship between population abundance and body size of morphospecies. We can find no evidence that body size-abundance patterns are triangular in complete communities. However, there is weak evidence that the relationship in the aquatic subsets of those communities may have some underlying triangularity, with medium-sized species having the largest populations.