Earthworms inhabiting bromeliads in Mexican tropical rainforests: ecological and historical determinants

Autor: Patricia Rojas-Fernández, Carlos Fragoso
Rok vydání: 1996
Předmět:
Zdroj: Scopus-Elsevier
ISSN: 1469-7831
0266-4674
DOI: 10.1017/s0266467400009925
Popis: In tropical rainforests, earthworms are currently found in litter, soils, the bark of decaying logs, in tree trunks and in bromeliads. The majority of reports on earthworms inhabiting tank bromeliads mention only their presence (Beutelspacher 1971, Laessle 1961, Mitchell 1986, Picado 1913), but little has been reported concerning their demography, dispersion, seasonal patterns in abundance and habitat specificity. Some studies provide estimations of total abundance (Lounibos et al. 1987, Paoletti et al. 1991), but only in one case is information provided at the species level (Lavelle & Kohlmann 1984). Colonization of aboveground habitats by earthworms has been explained by two ecological hypotheses: (1) a temporal shift in response to seasonal flooding of soils (Adis & Righi 1989) and (2) a permanent response to acidity, water saturation and low oxygen content of soils that occur in very wet tropical forests (Lee 1983). While studying the soil earthworm communities of Chajul tropical rainforest we became interested in the ecology of bromeliad earthworms. The main objectives of the study were to evaluate the habitat specificity of species and to obtain data on their abundance and spatial distribution. We also inquired into the causes of the bromeliad habitat shift, and its relationship with the two former hypotheses. Chajul is located in south-eastern Mexico (160 07' N, 900 55' W), 8 km away from the Guatemalan border. It is a seasonal tropical rainforest with a dry season (monthly precipitations less than 100 mm) of four months (JanuaryApril); the mean temperature and annual rainfall are 25.3?C and 2963 mm, respectively (for details on vegetation and soil types see Fragoso & Lavelle
Databáze: OpenAIRE
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