Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (10): 991-1002.DOI: 10.17521/cjpe.2015.0465

• Research Articles • Previous Articles     Next Articles

Relationships between soil nutrients and plant functional traits in different degradation stages of Leymus chinensis steppe in Nei Mongol, China

Dan LI1, Saruul KANG1,*, Meng-Ying ZHAO1, Qing ZHANG1,2, Hai-Juan REN1, Jing REN1, Jun-Mei ZHOU1, Zhen WANG1, Ren-Ji WU1, Jian-Ming NIU1,2,*   

  1. 1College of Life Sciences, Inner Mongolia University, Hohhot 010021, China

    2Sino-US Center for Conservation, Energy and Sustainability Sciences, Inner Mongolia University, Hohhot 010021, China
  • Online:2016-10-10 Published:2016-11-02
  • Contact: Saruul KANG,Jian-Ming NIU

Abstract:

Aims Understanding ecological implications of plant functional traits is helpful in exploring community assembly under different environments of nature and human disturbances, and then to reveal the maintenance mechanism of the ecosystem services. By analyzing vegetation and soil data derived from field observations in Leymus chinensis steppe of Xilin River Basin in Nei Mongol, we aimed to explore the responses of plant functional traits to changing soil nutrients at different degradation stages. Methods We observed 69 plots for both plant community structure and soil attributes using quadrat and soil-drilling methods. Five plant functional traits, namely the specific leaf area (SLA), leaf dry matter content (LDMC), leaf carbon to nitrogen ratio (C:N), leaf lignin content (LLC), and maximum height (MH), were measured for each plot. We also tested soil attributes, such as total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and organic carbon (OC). The sixty-nine communities were classified into four groups (undegraded L. chinensis + forbs, slightly degraded L. chinensis + Stipa sp., moderately degraded L. chinensis + Cleistogenes squarrosa, and heavily degraded L. chinensis + Artemisia frigida) using TWINSPAN software. The relationships between plant functional traits and soil nutrient variables were analyzed for the four community groups using the Pearson’s correlation test with SPSS 21.0 software. Important findings (1) The soil nutrients decreased with the grassland degradation process and there were significant differences in TN and TP between the undegraded L. chinensis + forbs and heavily degraded L. chinensis + A. frigida communities; (2) plant functional traits also showed strong differences between the degradation stages. MH and C:N decreased with degradation. A significant difference was observed in MH between the undegraded L. chinensis + forbs and slightly degraded L. chinensis + Stipa sp. communities. The difference in C:N was also significant between the undegraded L. chinensis + forbs and heavily degraded L. chinensis + A. frigida communities; (3) the effects of soil nutrients on plant functional traits changed with grassland degradation. AN was negatively correlated with MH, LLC, and C:N in the slightly degraded L. chinensis + Stipa sp. community. In the moderately degraded L. chinensis + C. squarrosa community, those three traits mentioned above showed significantly positive correlations with TP; (4) while analyzing the degraded grassland, different relationships between plant functional traits were found. In the slightly degraded L. chinensis + Stipa sp. community, LLC was positively correlated with all other traits. Moreover, positive correlations also occurred between C:N and MH, C:N and LDMC, and C:N and LLC. In the heavily degraded L. chinensis + A. frigida community, all traits demonstrated the most significantly positive correlations.

http://jtp.cnki.net/bilingual/detail/html/ZWSB201610003

Key words: plant functional traits, soil nutrient, degradation succession, the Leymus chinensis steppe, Xilin River Basin