Nitrogen and Phosphorus Concentration in Leaf Litter and Soil in Xishuangbanna Tropical Forests: Does Precipitation Limitation Matter?

S Mani,Min Cao

doi:10.3390/f10030242

Abstract

Tropical forests are generally expected to be limited by the availability of nitrogen (N) and phosphorus (P), and these nutrient limitations could be increased by changes in forest biogeochemistry due to limited precipitation. This effect is presumed to be enhanced in the forests predominated by monsoon climate. The present study examined the impacts of monthly precipitation on total N and P in leaf litter and soil of Xishuangbanna tropical forests. Litterfall and top soil were sampled from each of the five 20 × 20 m plots established in the primary (PTF) and secondary tropical forests (STF), at monthly interval for one year. Soils were strongly acidic and showed significant differences between the sites. The monthly amounts of soil and leaf litter nutrients showed great variations between the PTF and STF. Leaf litter N and P were associated with precipitation in both dry and rainy seasons. Soil N and P were not significantly related to precipitation, indicating that changes in vegetation composition and litterfall production together accounted for variation in soil N and P. Our results suggest that the precipitation limitation may affect the leaf litter N and P changes, but did not support the prediction that precipitation limitation can immediately lead to effects on soil N and P in the Xishuangbanna tropical forests.

Highlights

In tropical forest ecosystems, nitrogen (N) and phosphorus (P) are the most important limiting nutrients for carbon sequestration [1]
The degrees of variation (CV, %) for total litterfall, leaf litter N and P were higher in Primary Tropical Forest (PTF) than
secondary tropical forest (STF), and those for soil N and P were higher in STF than PTF

Summary

Introduction

In tropical forest ecosystems, nitrogen (N) and phosphorus (P) are the most important limiting nutrients for carbon sequestration [1]. Low P availability is usually expected [3] in tropical forest ecosystems N limitation is common [4]. These nutrient limitations could be exacerbated by changes in forest biogeochemistry in response to less rainfall [5]. Climate and soil quality are widely recognized as major drivers of virtually all properties of ecosystems and communities. The effects of climate on soil properties are not widely appreciated, despite major advances in the understanding of soil formation and ecosystem dynamics [8]

Objectives

Methods

Results

Discussion

Conclusion