Plant functional diversity and species diversity in the Mongolian steppe.

Indree Tuvshintogtokh,Xiufang Xie,Bayart Mandakh,Xuehua Ye,Duo Ye,Zhenying Huang,Guofang Liu,Ming Dong

doi:10.1371/journal.pone.0077565

Abstract

BackgroundThe Mongolian steppe is one of the most important grasslands in the world but suffers from aridization and damage from anthropogenic activities. Understanding structure and function of this community is important for the ecological conservation, but has seldom been investigated.Methodology/Principal FindingsIn this study, a total of 324 quadrats located on the three main types of Mongolian steppes were surveyed. Early-season perennial forbs (37% of total importance value), late-season annual forbs (33%) and late-season perennial forbs (44%) were dominant in meadow, typical and desert steppes, respectively. Species richness, diversity and plant functional type (PFT) richness decreased from the meadow, via typical to desert steppes, but evenness increased; PFT diversity in the desert and meadow steppes was higher than that in typical steppe. However, above-ground net primary productivity (ANPP) was far lower in desert steppe than in the other two steppes. In addition, the slope of the relationship between species richness and PFT richness increased from the meadow, via typical to desert steppes. Similarly, with an increase in species diversity, PFT diversity increased more quickly in both the desert and typical steppes than that in meadow steppe. Random resampling suggested that this coordination was partly due to a sampling effect of diversity.Conclusions/SignificanceThese results indicate that desert steppe should be strictly protected because of its limited functional redundancy, which its ecological functioning is sensitive to species loss. In contrast, despite high potential forage production shared by the meadow and typical steppes, management of these two types of steppes should be different: meadow steppe should be preserved due to its higher conservation value characterized by more species redundancy and higher spatial heterogeneity, while typical steppe could be utilized moderately because its dominant grass genus Stipa is resistant to herbivory and drought.

Highlights

As one of the most important contemporary environmental problems, the loss of biodiversity has become a major topic of concern [1]
The study was performed in three types of steppes in the central Mongolian steppe belt (Figure 1), which was authorized by Institute of Botany, Mongolian Academy of Sciences (MAS)
The dominant plant functional type (PFT) in meadow steppe were subdominant in typical steppe (Table 2, Figure 2)

Summary

Introduction

As one of the most important contemporary environmental problems, the loss of biodiversity has become a major topic of concern [1]. On-going climate changes threaten species diversity in natural ecosystems [2,3,4,5,6], especially in drylands [7]. There are three main types of steppes including the meadow, typical and desert steppes, which are all ecologically fragile as they are sensitive to climate changes, anthropogenic disturbances or both [14]. In recent years, overgrazing and cultivation activities have reduced their vegetation cover, which is critical to protect steppes from wind erosion [15]. These landuses have led to a conversion of vegetation type from typical to desert steppes [16]. Despite high potential forage production shared by the meadow and typical steppes, management of these two types of steppes should be different: meadow steppe should be preserved due to its higher conservation value characterized by more species redundancy and higher spatial heterogeneity, while typical steppe could be utilized moderately because its dominant grass genus Stipa is resistant to herbivory and drought

Objectives

Methods

Results

Discussion

Conclusion