β-Diversity of Functional Groups of Woody Plants in a Tropical Dry Forest in Yucatan

Abstract

Two main theories have attempted to explain variation in plant species composition (β-diversity). Niche theory proposes that most of the variation is related to environment (environmental filtering), whereas neutral theory posits that dispersal limitation is the main driver of β-diversity. In this study, we first explored how α- and β-diversity of plant functional groups defined by growth form (trees, shrubs and lianas, which represent different strategies of resource partitioning), and dispersal syndrome (autochory, anemochory and zoochory, which represent differences in dispersal limitation) vary with successional age and topographic position in a tropical dry forest. Second, we examined the effects of environmental, spatial, and spatially-structured environmental factors on β-diversity of functional groups; we used the spatial structure of sampling sites as a proxy for dispersal limitation, and elevation, soil properties and forest stand age as indicators of environmental filtering. We recorded 200 species and 22,245 individuals in 276 plots; 120 species were trees, 41 shrubs and 39 lianas. We found that β-diversity was highest for shrubs, intermediate for lianas and lowest for trees, and was slightly higher for zoochorous than for autochorous and anemochorous species. All three dispersal syndromes, trees and shrubs varied in composition among vegetation classes (successional age and topographic position), whilst lianas did not. β-diversity was influenced mostly by proxies of environmental filtering, except for shrubs, for which the influence of dispersal limitation was more important. Stand age and topography significantly influenced α-diversity across functional groups, but showed a low influence on β-diversity –possibly due to the counterbalancing effect of resprouting on plant distribution and composition. Our results show that considering different plant functional groups reveals important differences in both α- and β-diversity patterns and correlates that are not apparent when focusing on overall woody plant diversity, and that have important implications for ecological theory and biodiversity conservation.

Succession of Ephemeral Secondary Forests and Their Limited Role for the Conservation of Floristic Diversity in a Human-Modified Tropical Landscape

“…To our knowledge, this is the first study to assess changes in the diversity and composition of a metacommunity of secondary forests during succession [61], [62], [63]. Our data show that an important part of the compositional variation across the metacommunity of secondary forests in the Agua Salud area is structured along a successional gradient, with early successional sites that are compositionally more similar to each other than to later successional sites and vice versa.…”

Recovery and early succession after experimental disturbance in a seasonally dry tropical forest in Mexico

“…These six species had resprouted, which allowed their rapid recovery after clearing. Other studies in SDTF have shown that resprouting is a common and effective mechanism of regeneration (Ewel, 1980;Murphy and Lugo, 1986;Negreros-Castillo and Hall, 2000;Kennard, 2002;McLaren and McDonald, 2003;Sampaio et al, 2007;López-Martínez et al, 2013). Another study, in gaps caused by similar disturbances, found that 81% of the species had resprouted within 14 months after cutting stems of dbh >2 cm (McLaren and McDonald, 2003).…”

“…The ability of species to maintain themselves as part of a new stand also depends on individual structural characteristics and competitive capacities (Yih et al, 1991;Williams-Linera et al, 1997Gaudet and Kaedy, 1988;Vandermeer et al, 2000;Dupuy et al, 2012;López-Martínez et al, 2013). Floristic composition is influenced by the nature of the disturbance (magnitude, frequency and intensity) and the condition of a community when the disturbance occurs (Kellman, 1970).…”

“…Chronosequence studies evaluate changes based on a comparison of various plots of different seral ages, while vegetation dynamics studies document the development of the vegetation in permanent plots, through remeasurements (Chazdon et al, 2007). Most studies in tropical vegetation have been carried out on chronosequences (Westman, 1990;Williams-Linera, 1990;Randall and Pickett, 1992;Snook, 1993;Denslow, 1995;Williams-Linera et al, 2011;Dupuy et al, 2012;López-Martínez et al, 2013). The main disadvantage of these studies is that they use spatially discrete locations to represent changes taking place over time (Pickett, 1989), so data show the net cumulative effect of both spatial and temporal differences.…”

Relating species richness to the structure of continuous landscapes: alternative methodological approaches

“…), but other factors such as individual (meta)population dynamics, herbivore–plant interactions, or strongly autocorrelated biophysical phenomena may be involved (López‐Martínez et al. ).…”