The relative importance of climate, stand variables and liana abundance for carbon storage in tropical forests

Abstract

Aim To develop an integrative framework to evaluate variation in aboveground carbon storage (AGC). A model that can be applied to understand and predict how global‐change drivers influence tropical carbon sinks. Location Old‐growth tropical forests world‐wide. Methods Using structural equation modelling (SEM), we propose an a priori model to evaluate the direct and indirect effects of climate, stand variables (basal area, tree diameter and wood density at plot level) and liana abundance on AGC. Our model indicated that stand variables increased AGC while liana abundance decreased AGC indirectly via negative effects on stand variables. We used a multigroup SEM to test the generality of our framework using a standardized dataset of 145 plots (0.1 ha) in dry, moist and wet tropical forests. Results Our model explained over 85% variation in AGC and showed a positive and consistent relationship between stand variables and AGC across forests types. The effects of climate on AGC were indirect rather than direct, with negative effects of temperature in all forests. Liana abundance reduced tree diameter and basal area in moist forests, but did not affect AGC in wet or dry forests. Main conclusions Our results suggest that climate affects AGC indirectly, via its direct influence on stand variables and liana abundance. The effects of lianas on AGC result from reductions in stand variables and are as important as climate for moist forests, which harbour the greatest tropical carbon pools. Our model was consistent across forest types. This highlights the usefulness of an integrative framework to improve predictions of the effects of drivers of global change on tropical carbon sinks.

Do fragment size and edge effects predict carbon stocks in trees and lianas in tropical forests?

“…; Durán et al . ). There are four good reasons why lianas are more successful than trees in these conditions.…”

Global change effects on humid tropical forests: Evidence for biogeochemical and biodiversity shifts at an ecosystem scale

“…A 3 year liana removal experiment in a humid lowland Panamanian forest found an overall increased in woody biomass following liana removal, with woody stems going from 29% to 44% of aboveground biomass when lianas were absent [ van der Heijden et al ., ]. A recent model simulation also indicated that rising temperatures and increased dryness favored liana growth, with an overall negative effect on aboveground forest C storage [ Duran et al ., ]. Thus, reductions in tree biomass in favor of other life forms may reduce aboveground C storage in tropical forests with climate change.…”

Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance

“…The relationship between biodiversity and carbon storage is being debated as one of the current ecological topics (Cavanaugh et al, 2014;Day, Baldauf, Rutishauser, & Sunderland, 2014;Ruiz-Benito et al, 2014;Ruiz-Jaen & Potvin, 2011), and some aspects of climate-related effects have been well investigated (Durán, Sánchez-Azofeifa, Rios, & Gianoli, 2015;Wu et al, 2015). Because biomass is an important component of forest stand productivity, the relationship between biomass carbon and biodiversity can also be assimilated to the one of biodiversity and ecosystem function (Lasky et al, 2014).…”