Spatial and Seasonal Variation in Rain Use Efficiency in Semiarid Grasslands of Inner Mongolia

Jyoti Bhandari,Xuebiao Pan,G C Dhruba Bijaya

doi:10.1155/2015/917415

Abstract

Rain use efficiency (RUE) is an important indicator for identifying the response of plant production to variation in precipitation patterns, especially in semiarid ecosystem grasslands of Inner Mongolia. We have investigated the response and spatial patterns of RUE to precipitation patterns based on five years (2006, 2007, 2008, 2012, and 2013) of records from semiarid ecosystem sites across Inner Mongolia. Our results showed thatRUEADMwas lowest in the wettest year (2012) and highest in the year following the driest year (2008). There was no significant correlation betweenRUEADMandRUETDMin typical and desert steppe.RUETDMwas strongly correlated with both annual precipitation (AP) and growing season precipitation (GSP) compared toRUEADM.RUEADM, therefore, cannot be used in place ofRUETDM.RUEADMincreased with species richness. The relationship betweenRUEADMand species richness was significantly correlated in meadow steppe, typical steppe, and desert steppe. Our findings can shed light on the spatial utilization pattern of seasonal rainfall in semiarid grassland ecosystems.

Highlights

In arid and semiarid ecosystems, precipitation is an important factor in controlling biodiversity and ecosystem functioning [1]
We found that RUEADM, based on above ground dry matter, varied from 0.19 to 0.86 g m−2 mm−1 and was highest in meadow steppe and lowest in desert steppe (Table 1)
This study provides a broad analysis of Rain use efficiency (RUE) based on both above ground dry matter and total dry matter in 3 semiarid grassland types in the Inner Mongolia of China

Summary

Introduction

In arid and semiarid ecosystems, precipitation is an important factor in controlling biodiversity and ecosystem functioning [1]. Rain use efficiency (RUE) is defined as the amount of biomass produced per unit of precipitation and is the key indicator for measuring the response of plant production to precipitation [2,3,4]. Factors such as vegetation composition, soil condition, and biogeochemical constraints may affect rain use efficiency [2, 3, 5, 7]. Higher diversity of plant species and functional groups may have greater RUE through increased productivity [4, 7, 9,10,11,12]. The interaction of RUE with seasonal precipitation patterns and spatial patterns of both above ground dry matter (ADM) and total dry matter (TDM) is not fully understood. Total dry matter is the sum of ADM and below ground dry matter (BDM)

Methods

Results

Conclusion