Floristic structuring of woody plants from the Chaco in light of abiotic factors

Abstract

The phytogeographic domains are structured by different geoclimatic (abiotic) factors, such as altitude, temperature and precipitation. Thus, our goal was to investigate the possible abiotic factors that are related to the floristic richness of the tree-shrub component throughout the Chaco remnants. This study is based on data of the presence and absence of species in different remnants related to geoclimatic data. In addition, World Wildlife Fund shapes were used to differentiate dry and wet Chaco. The database aggregated 36 areas and 522 species. The different clusters obtained by floristic affinity between groups in Chaco was mainly related to temperature, altitude and seasonality of precipitation. In remnants where the seasonality of precipitation and altitude were more evident, there is greater dissimilarity in the composition of the tree-shrub vegetation. On the other hand, the temperature gradient explained the floristic homogeneity in the humid Chaco. Thus, the richness of the tree-shrub component of the Chaco is mainly attributed to three geoclimatic factors. Dry Chaco presents greater floristic dissimilarity compared to Humid Chaco. Still, the seasonality of the precipitation and the altitude play a dominant role in the structuring of trees and shrubs in the Dry Chaco and the temperature in the most homogeneous formations that integrate the humid Chaco.

Revealing the influence of climatic variables on the distribution of legume dispersal traits in the Chaco

“…For the Chaco, however, our analyses showed that the seasonality of both climatic variables shapes the distribution of morphological traits of Fabaceae and, considering that the family is highly representative in terms of richness and abundance in the biome (Lima et al 2015;Morales et al 2019), we expect a similar pattern to be found for the vegetation in general. It is worth mentioning that the Chaco is formed by a mosaic of dry vegetation, with the presence of forested, savannah, and monodominance regions of species (e.g., Schinopsis balansae) (Prado 1993) and, in the case of more extensive geographic scales, all vegetation structure in the biome is correlated to abiotic factors such as climate (Assunção et al 2022).…”

“…Environmental predictors such as climate and soil properties are some of the modulators of species distribution and richness around the globe on different spatial scales (Dell et al 2011;Jara-Guerrero et al 2011;Moles et al 2014;Payne et al 2018;Baptista et al 2020;Assunção et al 2022).…”