Will seasonally dry tropical forests be sensitive or resistant to future changes in rainfall regimes?

Abstract

Seasonally dry tropical forests (SDTF) are located in regions with alternating wet and dry seasons, with dry seasons that last several months or more. By the end of the 21st century, climate models predict substantial changes in rainfall regimes across these regions, but little is known about how individuals, species, and communities in SDTF will cope with the hotter, drier conditions predicted by climate models. In this review, we explore different rainfall scenarios that may result in ecological drought in SDTF through the lens of two alternative hypotheses: 1) these forests will be sensitive to drought because they are already limited by water and close to climatic thresholds, or 2) they will be resistant/resilient to intra-and inter-annual changes in rainfall because they are adapted to predictable, seasonal drought. In our review of literature that spans microbial to ecosystem processes, a majority of the available studies suggests that increasing frequency and intensity of droughts in SDTF will likely alter species distributions and ecosystem processes. Though we conclude that SDTF will be sensitive to altered rainfall regimes, many gaps in the literature remain. Future research should focus on geographically comparative studies and well-replicated drought experiments that can provide empirical evidence to improve simulation models used to forecast SDTF responses to future climate change at coarser spatial and temporal scales.

Functional organization of woody plant assemblages along precipitation and human disturbance gradients in a seasonally dry tropical forest

“…Accordingly, the traits we found to be responsive to CAD were those related to both light capture and water conservation strategies (i.e., leaf area and specific leaf area; Westoby et al, ; Wright et al, ; Wright et al, ). On the other hand, precipitation has been recognized as a key driver of community‐level patterns in SDTFs (Allen et al, ; Díaz & Cabido, ; Le Bagousse‐Pinguet et al, ; Maestre et al, ), including in Caatinga dry forests, particularly through environmental filtering acting on species and trait distribution (Rito, Arroyo‐Rodríguez, et al, ; Sfair et al, ). Previous studies have in fact proposed that changes in precipitation may be more important than CAD (Rito, Arroyo‐Rodríguez, et al, ).…”

Effects of seasonal precipitation change on soil respiration processes in a seasonally dry tropical forest

“…Miranda., ; Wilson, Marra, & Sillett, ). However, there are few studies directly exploring the effects of seasonal precipitation changes on soil respiration (Allen et al, ). In this study, we delayed the wet season (DW) for two months by reducing throughfall during early wet season and then adding water during early dry season.…”

Climate severity and land‐cover transformation determine plant community attributes in Colombian dry forests

“…Water deficit, as the result of drought conditions, may induce cavitation and hydraulic failure (Markesteijn, Poorter, Paz, Sack & Bongers, ; Méndez‐Alonzo, Paz, Cruz, Rosell & Olson, ; Pineda‐García, Paz, Meinzer & Angeles, ), which in turn have negative consequences on plant growth, recruitment, and survival (Allen et al., ). Thus, the intensity of dry seasons is likely to be one of the main drivers of plant community assembly and forest structure across TDF (Allen et al., ; Murphy & Lugo, ).…”