Simulating carbon stocks and fluxes of an African tropical montane forest with an individual-based forest model.

Rico Fischer,Andreas Huth,Michael Kleyer,Andreas Hemp,David Schellenberger Costa,Markus Fischer,Gemma Rutten,Andreas Ensslin,Sebastian Paulick,Robert Planque

doi:10.1371/journal.pone.0123300

Abstract

Tropical forests are carbon-dense and highly productive ecosystems. Consequently, they play an important role in the global carbon cycle. In the present study we used an individual-based forest model (FORMIND) to analyze the carbon balances of a tropical forest. The main processes of this model are tree growth, mortality, regeneration, and competition. Model parameters were calibrated using forest inventory data from a tropical forest at Mt. Kilimanjaro. The simulation results showed that the model successfully reproduces important characteristics of tropical forests (aboveground biomass, stem size distribution and leaf area index). The estimated aboveground biomass (385 t/ha) is comparable to biomass values in the Amazon and other tropical forests in Africa. The simulated forest reveals a gross primary production of 24 tcha-1yr-1. Modeling above- and belowground carbon stocks, we analyzed the carbon balance of the investigated tropical forest. The simulated carbon balance of this old-growth forest is zero on average. This study provides an example of how forest models can be used in combination with forest inventory data to investigate forest structure and local carbon balances.

Highlights

Tropical forests have long been recognized as highly productive ecosystems [1]
The comparison is made on the level of plant functional types (PFT)
We found that shade-tolerant (PFT1&2) and intermediate shade-tolerant (PFT3) tree species are most dominant in the investigated forest

Summary

Introduction

Tropical forests have long been recognized as highly productive ecosystems [1]. As such, these forests play a key role in the global carbon cycle. More than 50% of global carbon stored in living biomass is located in the tropics [2]. These forests are considered as a carbon sink with 1.2 Gt C per year [2,3,4]. Whether tropical forests serve as carbon sinks or sources is unclear due to their heterogeneity and the potential impacts of climate change and land use [5,6]. While most studies of tropical forests concentrate on regions in PLOS ONE | DOI:10.1371/journal.pone.0123300 April 27, 2015

Methods

Results

Conclusion