Community-wide spatial and temporal discordances of seed-seedling shadows in a tropical rainforest

PLoS One. 2015 Apr 9;10(4):e0123346. doi: 10.1371/journal.pone.0123346. eCollection 2015.

Abstract

Several factors decrease plant survival throughout their lifecycles. Among them, seed dispersal limitation may play a major role by resulting in highly aggregated (contagious) seed and seedling distributions entailing increased mortality. The arrival of seeds, furthermore, may not match suitable environments for seed survival and, consequently, for seedling establishment. In this study, we investigated spatio-temporal patterns of seed and seedling distribution in contrasting microhabitats (bamboo and non-bamboo stands) from the Brazilian Atlantic Forest. Spatial distribution patterns, spatial concordance between seed rain and seedling recruitment between subsequent years in two fruiting seasons (2004-2005 and 2007-2009), and the relation between seeds and seedlings with environmental factors were examined within a spatially-explicit framework. Density and species richness of both seeds and seedlings were randomly distributed in non-bamboo stands, but showed significant clustering in bamboo stands. Seed and seedling distributions showed across-year inconsistency, suggesting a marked spatial decoupling of the seed and seedling stages. Generalized linear mixed effects models indicated that only seed density and seed species richness differed between stand types while accounting for variation in soil characteristics. Our analyses provide evidence of marked recruitment limitation as a result of the interplay between biotic and abiotic factors. Because bamboo stands promote heterogeneity in the forest, they are important components of the landscape. However, at high densities, bamboos may limit recruitment for the plant community by imposing marked discordances of seed arrival and early seedling recruitment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brazil
  • Ecosystem*
  • Fruit / growth & development
  • Rainforest*
  • Seedlings / growth & development*
  • Seeds / growth & development*
  • Soil
  • Tropical Climate

Substances

  • Soil

Grant support

This study received financial support from the São Paulo Research Foundation (FAPESP 03/11073-7) and from the Brazilian National Research Council (CNPq 143107/2006-2) to DCR, and was framed within the Biota project supported by São Paulo Research Foundation (FAPESP 99/09635-0) granted to RRR (project leader). MAP received a research grant from CNPq (303559/2008-0), and PJ was granted by an Excellence grant from Junta de Andalucía, Spain (RNM2010-5731), CYTED-XII project 409AC0369, a Ciência sem Fronteiras grant (CNPq 401258/2012-2), as well as a Severo Ochoa Excellence Award from the Ministerio de Economía y Competitividad (SEV-2012-0262). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.