Modeling the impact of liana infestation on the demography and carbon cycle of tropical forests. (11th September 2019)

• Record Type: Journal Article
• Authors: di Porcia e Brugnera, Manfredo; Meunier, Félicien; Longo, Marcos; Krishna Moorthy, Sruthi M.; De Deurwaerder, Hannes; Schnitzer, Stefan A.; Bonal, Damien; Faybishenko, Boris; Verbeeck, Hans
• Is Part Of: Global change biology. Volume 25:Number 11(2019)
• Page Start: 3767
• Page End: 3780
• Publication Date: 2019-09-11
• Subjects: carbon dynamics -- dynamic global vegetation model -- ecology -- lianas -- plant functional type -- tropical forest; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.14769
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: There is mounting empirical evidence that lianas affect the carbon cycle of tropical forests. However, no single vegetation model takes into account this growth form, although such efforts could greatly improve the predictions of carbon dynamics in tropical forests. In this study, we incorporated a novel mechanistic representation of lianas in a dynamic global vegetation model (the Ecosystem Demography Model). We developed a liana‐specific plant functional type and mechanisms representing liana–tree interactions (such as light competition, liana‐specific allometries, and attachment to host trees) and parameterized them according to a comprehensive literature meta‐analysis. We tested the model for an old‐growth forest (Paracou, French Guiana) and a secondary forest (Gigante Peninsula, Panama). The resulting model simulations captured many features of the two forests characterized by different levels of liana infestation as revealed by a systematic comparison of the model outputs with empirical data, including local census data from forest inventories, eddy flux tower data, and terrestrial laser scanner‐derived forest vertical structure. The inclusion of lianas in the simulations reduced the secondary forest net productivity by up to 0.46 tC ha −1 year −1, which corresponds to a limited relative reduction of 2.6% in comparison with a reference simulation without lianas. However, this resulted in significantly reduced accumulated above‐ground biomass after 70 years of regrowth by up to 20 tC /ha (19% of the reference simulation). Ultimately, the simulated negative impact of lianas on the total biomass was almost completely cancelled out when the forest reached an old‐growth successional stage. Our findings suggest that lianas negatively influence the forest potential carbon sink strength, especially for young, disturbed, liana‐rich sites. In light of the critical role that lianas play in the profound changes currently experienced by tropical forests, this new model provides a robust numerical tool to forecast the impact of lianas on tropical forest carbon sinks. Abstract : This is the first dynamic vegetation model that simulates lianas. We predict a strong impact on the carbon stocks, especially for younger (secondary) forests where liana density is higher.