Liana functional assembly along the hydrological gradient in Central Amazonia

Abstract

Soil hydrology, nutrient availability and forest disturbance determine the variation of tropical tree species composition locally. However, most habitat ltering is explained by tree species' hydraulic traits along the hydrological gradient. We asked whether these patterns apply to lianas. At the community level, we investigated: (i) whether the hydrological gradient, soil fertility and forest disturbance explain liana species composition; and (ii) whether differences in leaf and stem wood functional traits were linked to species composition along ecological gradients. We sampled liana species composition in 18 1-ha plots across a 64 km² landscape in Central Amazonia and measured ten leaves and stem wood traits across 115 liana species in 2,000 individuals. We correlated liana species composition summarized with PCoA with the functional composition summarized by PCA, considering the species mean values of traits at the plot level. We tested the relationship between ordination axes and the environmental gradients. Liana species composition was highly correlated with functional composition. Taxonomic (PCoA) and functional (PCA) composition were strongly associated with the hydrological gradient, with a slight impact of forest disturbance on functional composition. Species at valley areas had higher stomata size and higher proportions of self-supporting xylem than plateau. Differently, lianas on plateaus invest more in fast-growing leaves (higher SLA), although with a higher wood density. Our study reveals that lianas use different functional solutions in dealing with each end of the hydrological gradient and that the relationships between habitat preferences and traits explain lianas species distributions not straightforwardly as previously found for trees.

Environmental heterogeneity influences liana community differentiation across a Neotropical rainforest landscape

“…For this latter study, the authors modeled climatic data describing a precipitation gradient related to changes in elevation even over small distances in the LTBS and showed the important role of these gradients in palm community differentiation, along with variation in soil water availability. Thus, these environmental variables are interrelated in a complex way and may be key drivers of plant community differentiation, as discussed in other liana studies (Liu et al, 2021(Liu et al, , 2023Manzané-Pinzón et al, 2018;Rocha et al, 2022;Romero-Saltos, 2011). Interestingly, the basal area data produced a contrasting ordination (Figure 5c), suggesting that environmental heterogeneity influences the establishment and biomass accumulation differentially among species.…”

Lianas in tropical dry forests have higher embolism resistance but similar hydraulic efficiency than lianas in rainforests

“…The vegetation of the Ducke Reserve was an old-growth perennial rainforest with a high diversity of tree and liana species. The forest has a closed canopy of 30-37 m and emerging trees reaching 45 m (Guillaumet and Kahn, 1982; Ribeiro et al , 1999; Rocha et al , 2022). The topography was heterogeneous, with elevations ranging from 40 to 140 m above sea level (Ribeiro et al , 1999).…”

The influence of forest structure on the abundance, biomass, and composition of lianas in tropical forest fragments

“…When we compare the number of species found in our study area, which attained a larger area than Laurance et al (2001), the number of species was almost double (47.7%) for 2.88 ha in the BDFFP. And for a region 80 km away, at the Ducke Reserve, our study comprises a third (33.1%) of the total lianas species inventoried there (Rocha et al 2022).…”

“…For the BDFFP areas,Laurance et al (2001) found that the abundance of lianas varied with soil edaphic factors, such as fertility, texture, and slope. In the Ducke Reserve, terrain height above nearest drainage (HAND) is a compositional descriptor for two of the most representative liana families: Bignoniaceae and Fabaceae(Schietti et al 2014;Gerolamo et al 2022;Rocha et al 2022). In the studies mentioned above, Bignonia aequinoctialis (Bignoniaceae) was found at shorter distances from the water table.…”

“…Rocha et al 2022) and the life stage of the individual(Nogueira et al 2011). In addition, the climbing guild is an essential parameter to analyze because there may be a signi cant relationship with tree size for the population of some species whose climbing strategy is based on tendrils and hooks(Laurance et al 2001;Yang et al 2018).…”