Habitat fragmentation disrupts a plant-disperser mutualism in the temperate forest of South America

RODRÍGUEZ-CABAL, M., M.A. AIZEN Y A. NOVARO

BIOLOGICAL CONSERVATION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2007 vol. 39 p. 195 - 202

0006-3207

The disruption of dispersal mutualisms may have profound consequences for seedlingrecruitment, plant demography, and population persistence, with potential cascadingeffects throughout the rest of the community. In the temperate forest of South America,the seeds of the mistletoe Tristerix corymbosus, a proposed key species, are dispersed solelyby the endemic marsupial Dromiciops gliroides. In three sites that included two contrastinghabitats, one fragmented and the other not, we assessed effects of forest fragmentation onmarsupial abundance, fruit removal, seed dispersal and seedling recruitment rates.We alsocompared the age structure of mistletoe populations between fragmented and non-fragmentedforest habitats. Fragmentation affected negatively marsupial abundance, fruitremoval, seed dispersal, and seedling recruitment. The local extinction of D. gliroides wasassociated with the complete disruption of mistletoe seed dispersal. Mistletoe populationsin fragmented forests exhibited a deficiency in juveniles because of a lack of recruitment.Thus, effects of forest fragmentation on this dispersal mutualism have clear demographicconsequences, which may compromise the survival of mistletoe populations.