How Tree Species Differ as Recruitment Foci in a Tropical Pasture

Abstract

In a Neotropical pasture, I predicted that two characteristics of trees, type of fruit produced and amount of shade cast, would affect recruitment and growth of woody plants underneath them. I also predicted that woody plants that persisted in active pasture would affect the species assemblages under trees after pasture abandonment. To investigate these hypotheses, I examined the assemblages of recruits under several types of trees in active pasture and also under similar trees that were fenced off (enclosed) to simulate abandoned pasture. The trees were Ficus spp. (fleshy fruits, deep shade), Pentaclethra macroloba (dry fruits, deep shade), Cecropia spp. (fleshy fruits, sparse shade), and Cordia alliodora (dry fruits, sparse shade). Recruitment into “open” pasture plots (i.e., without trees) was also examined. In active pasture, the species assemblage of woody recruits depended on the tree under which they grew. The assemblage under Ficus was dense and diverse, under Cecropia and Cordia it was moderately dense and diverse, in open pasture it was sparse and species‐poor, and under Pentaclethra it was dominated by its own seedlings. These patterns were found in the enclosed pasture as well, apparently because woody plants that had survived in the active pasture continued to grow after “abandonment.” However, after enclosure, many new plants also became established, such that the enclosed pasture plots had almost twice as many woody plants and species as the active pasture plots. Growth of woody plants was most rapid under trees with the least shade (Cecropia, Cordia) and in open pasture. In contrast, growth of recruits was slower under the much shadier Ficus, and thus, in the initial stages of succession, Ficus appeared not to be as important a “recruitment focus” for woody plants. Growth of recruits under the equally shady Pentaclethra was also slow, but Pentaclethra seedlings readily established just outside the canopies of parent trees, where they grew quickly and created dense, monospecific stands. The results of this study suggest that patterns of early succession to forest after pasture abandonment will depend on the kinds of trees found in the pasture. Persistent woody recruits under trees in active pasture constitute sources of advanced regeneration that will substantially affect forest succession after pasture abandonment.

Brachystegia boehmii and Brachystegia floribunda facilitate the establishment of montane forest trees in miombo woodland in northern Malawi

“…Similar facilitative effects have been reported in successional processes (Slocum 2001, Yoshihara et al 2010 and in the process of riparian forest tree encroachment into savannah (Shararn et al 2009). Hennenberg et al (2006) reported that fires can occur frequently with high grass cover, but rarely with low grass cover.…”

Isolated Ficus trees deliver dual conservation and development benefits in a rural landscape

“…In some cases, the average densities of plants were two (firewood, human food, livestock fodder, medicinal resources) or almost three (high-grade timber) times higher under Ficus trees than under non-Ficus trees. 2015, 44:678-684It appears likely that the higher densities of valuable plants growing under Ficus trees is a consequence of Ficus trees supporting higher plant densities per se, as has been demonstrated in studies from the Neotropics (Slocum 2001;Guevara et al 2004). However, the exact reasons for a higher density of useful plants growing under Ficus trees compared to non-Ficus trees are hard to disentangle.…”

“…Furthermore, if the areas under isolated Ficus trees are well managed, they are likely to provide important resources for local households over long timescales, aligning conservation and development objectives through community resource management (Hutton and LeaderWilliams 2003;Adams et al 2004;Martin et al 2009). As the cost of reducing grazing and vegetation clearance under Ficus trees is low (Barnes et al 2014), and as Ficus trees occur in rural landscapes across the tropics (Slocum 2001;Guevara et al 2004;Eshiamwata et al 2006;Caughlin et al 2012), the conservation of Ficus trees and the plant communities associated with them could yield low-cost improvements to human welfare on a global scale.…”

Bird Functional Traits Respond to Forest Structure in Riparian Areas Undergoing Active Restoration

“…Birds are widely used as bioindicators for the monitoring of ecosystems under restoration, as they commonly present fast responses to forest development [16][17][18] and perform important ecological functions such as pollination, seed dispersal, and predation [19][20][21]. Bird assemblages can show large shifts in their composition according to the vegetation successional stage [22][23][24][25].…”