Effects of litter manipulation on litter decomposition in a successional gradients of tropical forests in southern China.

Hao Chen,Shaofeng Dong,Jiangming Mo,Lei Liu,Tao Zhang,Shenglei Fu,Zhanfeng Liu,Geshere A Gurmesa,Chuan Ma,Ben Bond-Lamberty

doi:10.1371/journal.pone.0099018

Abstract

Global changes such as increasing CO2, rising temperature, and land-use change are likely to drive shifts in litter inputs to forest floors, but the effects of such changes on litter decomposition remain largely unknown. We initiated a litter manipulation experiment to test the response of litter decomposition to litter removal/addition in three successional forests in southern China, namely masson pine forest (MPF), mixed coniferous and broadleaved forest (MF) and monsoon evergreen broadleaved forest (MEBF). Results showed that litter removal decreased litter decomposition rates by 27%, 10% and 8% and litter addition increased litter decomposition rates by 55%, 36% and 14% in MEBF, MF and MPF, respectively. The magnitudes of changes in litter decomposition were more significant in MEBF forest and less significant in MF, but not significant in MPF. Our results suggest that change in litter quantity can affect litter decomposition, and this impact may become stronger with forest succession in tropical forest ecosystem.

Highlights

Litter decomposition is a key process that regulates nutrient recycling in ecosystems, influences net ecosystem carbon (C) storage, and is the first step in the formation of soil humus [1]
No significant difference in litter decomposition rate was found between mixed forest (MF) and masson pine forest (MPF) for all species
When compared within forest type, litter decomposition rate was significantly lower in chinensis Hanc (CC) leaf litter than in SS in the monsoon evergreen broadleaved forest (MEBF) and MF (Table 2, P = 0.037 and 0.021, respectively)

Summary

Introduction

Litter decomposition is a key process that regulates nutrient recycling in ecosystems, influences net ecosystem carbon (C) storage, and is the first step in the formation of soil humus [1]. Litter decomposition can be affected by many environmental factors including the physical environment (e.g. temperature, moisture, and soil pH), nutrients availability and activities of decomposers in the soil [2]. Litter quantity can alter microclimate, number and dynamics of decomposer organisms and nutrient availability in forest floor and mineral soil [3]. It has been reported that global climate changes due to rising atmospheric CO2 concentration and temperature can increase net primary production (NPP) and litter production in forest ecosystems [4,5,6]. Evaluating the effects of these changes in litter inputs on litter decomposition is crucial for our understanding of ecosystem nutrient supplies and future global C cycle

Objectives

Methods

Results

Discussion

Conclusion