Mass loss and nutrient release during the decomposition of sixteen types of plant litter with contrasting quality under three precipitation regimes.

Ningning Du,Yanjiang Zhang,Wenrao Li,Xiaorong Wei,Xingchang Zhang,Liping Qiu

doi:10.1002/ece3.6129

Abstract

Mass loss and nutrient release during litter decomposition drive biogeochemical cycling in terrestrial ecosystems. However, the relationship between the litter decomposition process and the decomposition stage, precipitation, and litter quality has rarely been addressed, precluding our understanding of how litter decomposition regulates nutrient cycling in various ecosystems and their responses to climate change. In this study, we measured mass loss as well as carbon and nutrient releases during the decomposition of 16 types of leaf litter under three precipitation treatments over 12 months in a common garden experiment (i.e., using standardized soil and climatic conditions). Sixteen types of leaves were divided into three functional groups (evergreen, deciduous, and herbaceous). The objectives were to understand the effects of decomposition stages and precipitation regimes on litter decomposition and to examine the relationship between this effect and chemical properties. The mass loss and release of nitrogen and potassium were significantly higher in the 6‐ to 12‐month stage of decomposition (high temperature and humidity) than in the 0‐ to 6‐month stage. Phosphorus was relatively enriched in evergreen leaves after 6 months of decomposition. The rates of mass loss and nutrient release were significantly greater in herbaceous than in deciduous and evergreen leaves. Increasing precipitation from 400 to 800 mm accelerated mass loss and potassium release but decreased phosphorus release in the 0‐ to 6‐month stage of decomposition. These results highlighted the contribution to and complexity of litter chemical properties in litter decomposition.

Highlights

The decomposition of litter in ecosystems plays an important role in mediating major ecosystem processes (Berg et al, 1993; Salinas et al, 2011; Zhou, Clark, Su, & Xiao, 2015) and sustaining the productivity and functionality of terrestrial ecosystems (Adair et al, 2008)
We present results regarding mass loss and nutrient release during the decomposition of the leaf litter under three precipitation scenarios to test the following hypotheses: (H1) Mass loss and nutrient release will increase with precipitation, and this response will be consistent across three functional groups of leaves; (H2) there will be a stronger mass loss and nutrient release response to different precipitation regimes in the early compared to the late stage of decomposition; and (H3) there is a strong correlation between the chemical properties of litter, and the contribution of these properties to mass loss and nutrient release will follow different models at different stages of decomposition
Our results further showed that significantly higher nutrient release occurred from the herbaceous and deciduous leaves than from the evergreen leaves (p < .001, Figure 2b), which is consistent with the patterns of influence of functional groups on the rate of mass loss (RM) (Figure 2b)

Summary

Introduction

The decomposition of litter in ecosystems plays an important role in mediating major ecosystem processes (Berg et al, 1993; Salinas et al, 2011; Zhou, Clark, Su, & Xiao, 2015) and sustaining the productivity and functionality of terrestrial ecosystems (Adair et al, 2008). Previous estimations have shown that approximately 90% of global terrestrial plant production is transferred into the dead organic matter pool, and the rest is consumed by herbivores (Cebrian, 1999). Among the production transferred into dead organic matter, approximately 76% is lost to the atmosphere (1.9 Mg C ha−1 year−1) and 24% is redistributed into the soil (Chambers, Schimel, & Nobre, 2001). Mass loss and nutrient release during the decomposition of litter have important links to ecosystem processes (Berg & McClaugherty, 2013). The study of the decomposition of plant litter on the Loess Plateau has important theoretical and guiding significance

Methods

Findings

Discussion

Conclusion