Biodiversity extinction thresholds are modulated by matrix type

Autor(es)

Boesing, Andrea Larissa ^[1] ; Nichols, Elizabeth ^[2] ; Metzger, Jean Paul ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Ecol, Sao Paulo, SP - Brazil

^[2] Swarthmore Coll, Dept Biol, Swarthmore, PA 19081 - USA

• Tipo de documento: Artigo Científico
• Fonte: ECOGRAPHY; v. 41, n. 9, p. 1520-1533, NOV 2018.
• Citações Web of Science: 10

Resumo

Biodiversity extinction thresholds are abrupt declines in biological diversity that occur with habitat loss, associated with a decline in habitat connectivity. Matrix quality should influence the location of thresholds along habitat loss gradients through its effects on connectivity; however these relationships have seldom been explored empirically. Using field data from 23 independent 1254 ha landscapes in the Brazilian Atlantic Forest, we evaluated how tropical avian biodiversity responds to native forest loss within habitat patches embedded either in homogeneous pasture matrix context (with a high proportion of cattle pastures), and heterogeneous coffee matrix context (with high abundance of sun coffee plantations). We considered taxonomic, functional, and phylogenetic diversity, and tested if matrix type and choice of diversity metric influenced the location of biodiversity thresholds along the forest cover gradient. We found that matrix type postponed the abrupt loss of taxonomic diversity, from a threshold of 35% of forest cover in homogeneous pasture matrix to 19% in heterogeneous coffee matrix. Phylogenetic diversity responded similarly, with thresholds at 30 and 24% in homogeneous-pasture and heterogeneous-coffee matrices, respectively, but no relationship with forest cover was detected when corrected for richness correlation. Despite the absence of a threshold for functional diversity in either matrix types, a strong decline below 20% of habitat amount was detected. Finally, below 20% native habitat loss, all diversity indices demonstrated abrupt declines, indicating that even higher-quality matrices cannot postpone diversity loss below this critical threshold. These results highlight that taxonomic diversity is a more sensitive index of biodiversity loss in fragmented landscapes, which may be used as a benchmark to prevent subsequent functional and phylogenetic losses. Furthermore, increasing matrix quality appears an efficient conservation strategy to maintain higher biodiversity levels in fragmented landscapes over a larger range of habitat loss. (AU)

• Processo FAPESP: 13/12777-0 - Influência da composição da paisagem e da diversidade funcional e filogenética das comunidades de aves na provisão do serviço de regulação de pragas agrícolas
• Beneficiário: Andrea Larissa Boesing
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/11676-8 - Quantificando a base mecanicista de serviços ecossistêmicos associados à regulação de doenças em paisagens agrícolas
• Beneficiário: Elizabeth Stevens Nichols
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/23457-6 - Projeto interface: relações entre estrutura da paisagem, processos ecológicos, biodiversidade e serviços ecossistêmicos
• Beneficiário: Jean Paul Walter Metzger
• Linha de fomento: Auxílio à Pesquisa - Programa BIOTA - Temático