Multiple Environmental Controls on Cockroach Assemblage Structure in a Tropical Rain Forest

摘要: Arthropod abundance and diversity are remarkable in tropical forests, but also spatially patchy. This has been attributed either to resources, predators, abiotic conditions or disturbances, whether such factors may simultaneously shape arthropod assemblage structure is little known. We used cockroaches test for multiple environmental controls on 25 km2 of Amazonian forest. performed nocturnal, direct searches 30 plots (250 m × 2 m) during two seasons, gathered data biotic from previous studies. Cockroach increased with dry litter mass, a measure resource amount, while species richness phosphorus content, availability. decreased ant relative abundance. composition changed along the gradient of: (1) soil clay which correlates broad differentiation between flood-prone non-flooded forest; (2) moisture, consistent known interspecific variation desiccation tolerance; (3) according ants, potential predator. Turnover was correlated conditions—sorting physiological requirements disturbance-related life history traits—and ants' selective pressure. abundance, diversity, seem be controlled by distinct sets factors, predators were represented emerged as common factor underlying cockroach distribution. Such patterns community have previously overlooked undue focus single few forest arthropods. Resumo A abundância e diversidade de artropodos sao notaveis em florestas tropicais, mas espacialmente variaveis devido fatores como recursos, predadores, condicoes abioticas ou perturbacoes. Pouco conhecido do quanto esses podem moldar simultaneamente assembleia artropodos. Usamos baratas para testar multiplos controladores ambientais sobre estrutura da floresta. Em dois periodos anuais, efetuamos busca ativa noturna parcelas obtivemos dados estudos anteriores. A riqueza aumentaram com disponibilidade (serrapilheira) qualidade (porcentagem fosforo serrapilheira) respectivamente. especies decresceu formigas. composicao mudou ao longo gradiente (i) teor argila solo, que se relaciona diferenciacao entre propensas nao inundacao; (ii) umidade consistente variacao interspecifica na tolerância dissecacao (iii) acordo mudanca foi correlacionada abioticos, selecionando requerimentos fisiologicos historia vida, tambem pressao seletiva abundância, parecem ser controladas por distintos, predadores—representados formigas—emergem um fator comum moldando distribuicao baratas. Este padrao comunidade tem sido negligenciado focos alguns pode aos tropicais.