Are extinction debts reflected in temporal changes of life history trait profiles? A fifteen-year reappraisal of bryophyte metacommunities in a fragmented landscape

Abstract

Forest fragmentation impacts community structure at both local and regional scales over time. Understanding the resilience of tropical forests to anthropogenic impacts and the period for communities to recover are critical steps for conservation policy implementation. We took advantage of a dynamic group of land plants to study temporal changes in their community structure over a period of 15years at a landscape-scale experimental fragmentation site in central Amazonia. We observed an overall increase in estimated epiphyll abundances and species richness in smaller fragments (1- and 10-ha reserves) suggesting recovery rather than a belated accumulation of local extinction events. However, higher turnover in smaller fragments, when compared to larger ones, was driven by increased presence of core species indicating interspecific differences in survivability. These disproportionate changes in occupancy patterns and relative abundances in fragments were best explained by life history traits reflecting increased dispersal capacity and physiological tolerances suggesting recovery of the phyllosphere community in smaller fragments (1- and 10-ha) over 15years. Even for this group renowned for fast generation times and high reproductive output, epiphyll metacommunities of smaller fragments have yet to recover from local extinctions accrued following the initial fragmentation nearly 40years ago. However, the interaction of dispersal capacities and physiological tolerances are playing a significant role in the recovery of their spatiotemporal distributional patterns in this experimentally fragmented landscape.