Distribution, ecology, and reproduction of bryophytes in a humid enclave in the semiarid region of northeastern Brazil

摘要

The ready availability of water resources distinguishes the humid forest of Chapada do Araripe, Ceará State, Brazil, from the semiarid vegetation around it. The regional climate demonstrates a marked seasonality of rainfall that affects the ecological strategies of the species found there. We studied the bryophytes of the humid forest of Chapada do Araripe, analyzing their diversity, geographic distributions, and ecological and reproductive aspects. Bryophytes were collected from different substrates using the random-walk method. We gathered information concerning the geographic distribution, functional groups (life forms, light tolerance guilds, and habits) and reproductive aspects of each taxon. We found 76 bryophyte species, predominantly mosses (45 species). Ten new occurrences were recorded for Ceará State, including a new taxon for northeastern Brazil. Most species are widely distributed in that country. Desiccation tolerant (turf) and intermediate (mat and weft) life forms predominated, as well as generalist species in terms of their light requirements. Sixty eight percent of the species demonstrated substrate preferences. Monoicous (67 %) sexual systems predominated over dioicous. The species displayed functional groups and reproductive aspects tolerant to adverse conditions that maximized the use of available resources and allowed their persistence under the seasonal conditions of the forest.