What Role Does Elevational Variation Play in Determining the Stock and Composition of Litter?

Abstract

This study analyzed the role of Caatinga vegetation structure in the accumulation, composition and distribution of litter along an elevation gradient in the Brazilian semi-arid region. Fifty sampling units were established for shrub-tree vegetation analysis, and 50 1-m 2 plots for sampling litter. Sampled litter was screened in fractions of leaves, stems, reproductive structures, miscellaneous and animal remains and then weighed. Total accumulated litter weighed 72.3 kg and was composed mainly of stems (45.2%). A positive correlation was found between total litter and elevation, as well as between leaf fraction and richness and basal area, while the stem fraction was negatively associated with richness, abundance and basal area. The results reflect a joint effect of abiotic factors and community structure, which produces heterogeneous environments that favor variation in litter production and quality along the elevation gradient.

Application of soil seed bank techniques to facilitate forest restoration in the Caatinga

“…The locations with altitudes and steeper slopes have a large volume of plant litter and consequently high species richness (Almeida et al, 2020). However, the Serra Branca collection environment had an altitude of up to 700 m, higher than Pimenteira, and showed lower species richness (Figure 3B).…”

“…In addition to that, the Serra Branca has a steep slope and rocky terrain, which interfere with the accumulation of dead plant biomass (necromass). Moreover, in this environment, there is a greater accumulation of leaves and branches, with the presence of recalcitrant components that cause a low decomposition rate in the semi-arid environment (Almeida et al, 2020) and, consequently, do not favor seed germination.…”

Effects of topographic factors on distribution of cacti along an elevation gradient in Brazilian Caatinga

“…Trails left by grazing domestic animals, mainly goats (Capra aegagrus), and selective cut marks in the vegetation, are commonly found at the base of the mountain (Diniz 2016; Ramos et al 2020). The intermediate portion to the top of Serra da Arara is characterized by greater rock cover, steep slopes and the presence of bromeliads (Almeida et al 2020; Diniz 2016) contribute to the formation of distinct microhabitats which has a more arboreal size, greater species richness and the presence of some typical taxa from more humid regions, when compared to lower altitude vegetation (Diniz 2016; Ramos et al 2020).…”

“…These areas have a set of particularities that make them indispensable environments for understanding the Caatinga and its environmental complexity (Silva et al 2014). Despite having a low altitudinal range, severe changes occur in the structure, composition and pattern of species richness, characterized by an increase in the number of species as the elevation gradient progresses (Lopes et al 2017;Almeida et al 2020).…”

“…For example, gravity-driven movement of nutrients from mountain top downwards has resulted in deeper and more fertile soils at the base of mountains (Santos et al 2009;Ramos et al 2020). In addition, the stock and composition of litter varies along these gradients, which can contribute to changes in patterns of species richness (Almeida et al 2020). Playing a synergetic role, anthropic disturbances are evident in the lower areas of these elevation gradients and, consequently, drive changes in land cover and in tree shrub communities (Silva et al 2014;Lopes et al 2017;Silva & Souza 2018).…”