Changing ecological communities along an elevation gradient in seasonally dry tropical forest on Hispaniola (Sierra Martín García, Dominican Republic)

Abstract

We report the results of systematic vascular plant and bird surveys in Seasonally Dry Tropical Forest (SDTF) across leeward and windward elevation gradients (31–884 masl) in the Sierra Martín García (SMG), Dominican Republic. We expected to see gradual, systematic changes in plant distributions with elevation owing to the strong effect of topoclimate. In contrast, we predicted bird community composition to be related only weakly to elevation, because we expected bird distributions to be more strongly related to vegetation structure than composition. Based on 48 vegetation transects, we identified seven groups that differed in their species composition, which was correlated with elevation and precipitation. The most distinctive vegetation community occurs in dry, warm, and low elevations on the leeward slope, featuring large numbers of non‐woody indicator species (those species found frequently within one group but not in other groups) even though most of its trees and shrubs represent species that are widespread. Low rainfall and shale bedrock (rather than limestone) may be the primary drivers of distinctiveness in the low‐elevation leeward plots. On the leeward slope, where we also surveyed the birds, the vegetation community changes gradually with elevation at mid‐ to high elevations. The most distinctive bird community also was associated with the low‐elevation forest on shale bedrock and was dominated by widespread species. At higher elevations, but still within leeward SDTF, the bird communities had a stronger component of species endemic either to Hispaniola or to Caribbean islands, and species turnover did not correspond to the elevation gradient. Abstract in Spanish is available with online material.

Spatial Occupancy, Local Abundance and Activity Rhythm of Three Ground Dwelling Columbid Species in the Forests of Guadeloupe in Relation to Environmental Factors

“…We detected ZD more frequently and in higher abundance at camera-trap survey locations that were dominated by flooded forest and dry forest, thus confirming previous observations [32,101,102]. In addition, Model 4 (∆AICc = 2.18) suggested that elevation had a marginal negative influence on the abundance of ZD, confirming recent observations on Hispaniola [103]. Conversely, we observed BQD more often in the tropical rainforest habitat, as previously reported [28].…”

Effects of land‐use change on avian taxonomic, functional and phylogenetic diversity in a tropical montane rainforest

“…The clearing of forest in the tropics is often concentrated at lower elevation habitats, leading to the loss of specific vegetation types and their associated bird assemblages (Franklin et al, 2019;Harris et al, 2014) Although birds have been the focus of many land use change studies worldwide, research coverage in the Afrotropics remains poor and is dominated by the evaluation of taxonomic diversity, which is not always sufficiently informative about ecosystem processes and responses to environmental disturbances (Cadotte et al, 2011;Mouillot et al, 2013;Petchey & Gaston, 2002;Walker et al, 1999).…”

“…For instance, the removal of mature trees (large and tall) affects canopy foragers and cavity nesters (Bonaparte et al., 2020; Lindenmayer, 2017), while changes in microclimatic and edaphic conditions, such as soil water content, affect the abundance of soil invertebrates, which avian insectivores consume (Cifuentes‐Croquevielle et al., 2020; Sutherland & Green, 2004). The clearing of forest in the tropics is often concentrated at lower elevation habitats, leading to the loss of specific vegetation types and their associated bird assemblages (Franklin et al., 2019; Harris et al., 2014). For example, (a) in the montane rainforests of Rwanda, Neate‐Clegg et al (2020) reported the upslope shift of bird communities following anthropogenic habitat transformation over 15 years in Nyungwe National Park, while (b) in the Volcanoes National Park, Rwanda, where the vegetation stratification is well marked, extirpation of bird species such as Cercococcyx montanus (Barred long‐tailed cuckoo) was documented after the clearance of the low‐elevation mixed forest (Vande weghe & Vande weghe, 2011).…”

Patterns of variation in plant diversity vary over different spatial levels in seasonal coastal wetlands

“…This provides excellent understanding of how biodiversity is impacted by individual drivers such as along temperature, precipitation or latitudinal gradients (Fitzpatrick et al, 2013;Franklin et al, 2019;Ibanez et al, 2018). However, environmental gradients are multivariate; multiple drivers of biodiversity change operate together.…”

“…While there is a large body of literature highlighting the role that spatial scale can play in shaping biodiversity patterns, they tend to focus on a single driver of diversity change. This provides excellent understanding of how biodiversity is impacted by individual drivers such as along temperature, precipitation or latitudinal gradients (Fitzpatrick et al, 2013; Franklin et al, 2019; Ibanez et al, 2018). However, environmental gradients are multivariate; multiple drivers of biodiversity change operate together.…”