Fitting abundance distribution models in tropical arboreal communities of SE Brazil

Abstract

The species abundance distribution of ecological communities has been represented through several mathematical models, of which the most common are: geometric series, logseries, lognormal, and a type of broken stick, this latter found only in animal communities. There is no consensus on the underlying biological processes, but initial observations on plant communities related these models to equilibrium and high richness (lognormal), stress or disturbance and low richness (logseries and geometric series). Recently the value of these relationships was challenged, and other descriptors were considered better predictors of richness, disturbance and stress. We aimed at investigating how these models and their parameters, as well as dominance and evenness are related with species richness, stress and disturbance in six tropical forest communities, SE Brazil: two well-conserved fragments, two disturbed by fire, and two swampy forests (anoxic stress). The models did not show consistent relationships with richness, disturbance or stress. The parameters and indices of diversity α (logseries) and λ (lognormal) varied closely with richness, and the dominance was larger in the communities submitted to stress or disturbance. Our results indicate the need of further studies in order to validate (or refute) the use of abundance distribution models for detection of patterns related to richness, stress or disturbance in tropical arboreal communities. On the other hand, richness and dominance did respond to disturbance and stress.

Effect of anthropogenic pressure on grasshopper (Orthoptera: Acridomorpha) species diversity in three forests in southern Cameroon

“…This distribution model shows that although they had different levels of utilization and degradation, these three forest ecosystems are disturbed by human activities (Hughes 1986). Under these conditions, the available resources may be immobilized by a small number of species that develop strategies of resistance to human disturbances (Ramade 2009, Cielo Filho et al 2012, Havyarimana et al 2013; this was the case of M. granulosa, S. opacula, and H. gerstaeckeri in the forests studied. The other species are relegated to the unfavorable areas (Ramade 2009), as was the case with G. opilionoides and P. femorata, two very rare species found only in the less degraded forest of Ngutadjap.…”

“…Abundance distribution models.-The abundance distributions of the reported species were compared to the geometric distribution model of Motomura, the broken stick model of Mac-Arthur, and the log series model of Fisher (Carlo et al 1998, Cielo Filho et al 2012, Havyarimana et al 2013, Marcon 2015 to find the one that fits most to our dataset. These models provide information on how species are distributed and on how they share the available resources in the ecosystem (Havyarimana et al 2013).…”

Checklist of coral reef fishes of Darvel Bay, Sabah, Malaysian Coral Triangle, with a note on the biodiversity and community structure

“…Darvel Bay's historical and ongoing IUU fishing activities and rapid land-use change may cause a possible phase shift in macroalgae communities resulting in reef fish community observed to follow a logseries model. The logseries model is commonly used to characterise the biological community experiencing disturbances and/or living in restricted environmental conditions ( Cielo Filho et al 2002 , Hill and Hamer 2004 ). The logseries model present a pattern of monopoly by a few dominant species and uneven distribution of species in a community ( Cielo Filho et al 2002 ; Magurran 2004 ).…”

Ecology of Floodplain Campos de Murundus Savanna in Southern Amazonia

“…This metric is the basis of many conservation studies (May 1988). Another important tool for the study of communities is the investigation of the patterns of distribution and species abundance and their comparison with predictions from mathematical models (Cielo-Filho et al 2002). For example, the spatial and statistical patterning of the species diversity of communities may help explain whether they are shaped by biotic interactions or are randomly assembled (Weiher and Keddy 1999;Gotelli and McCabe 2002).…”