Contrasting responses of plants and pollinators to woodland disturbance

COULIN, CAROLINA; AIZEN, MARCELO A.; GARIBALDI, LUCAS A.

AUSTRAL ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2019 vol. 44 p. 1040 - 1051

1442-9985

Preserving species diversity is critical to ensure ecosystem functioning; however, different components of diversity might respond to human disturbancein different ways. Similarly, trophic levels might have uncoupledresponses to the same disturbance, thus ameliorating or aggravatingthe persistence of ecological communities. In this study, we analysedhow the density, richness and evenness of flowers and pollinatorsrespond to four levels of woodland thinning intensity (0, 30, 50 and70% of woodland basal area removed) over 2 years in three contrastingsites. We found a mismatch in the response of flowers and pollinatorsto thinning. Flower density and richness had disparate responses,depending on the site and year, while evenness did not change withthinning. In contrast, pollinator density and richness, but notevenness, consistently increased with thinning among years and sites.These results suggest that thinning has a great influence onpollinators through changes in abiotic conditions and, perhaps,flower attractiveness rather than through small-scale changes inflower density and richness. At the site where tree flowers wereabsent, bee pollinator community composition was impoverished,suggesting that trees provide important floral resources topollinators. Our findings indicate that disturbance may diminishlocal plant abundance and richness, but pollinator abundance andrichness are enhanced after intense thinning at small scales.p { margin-bottom: 0.25cm; line-height: 120%; }