Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (4): 343-351.DOI: 10.17521/cjpe.2015.0033

• Orginal Article • Previous Articles     Next Articles

Community succession and photosynthetic physiological characteristics of pasture plants in a sub-alpine meadow in Gannan, China

CHEN Shi-Wei, LIU Min-Xia*(), JIA Yun, AN Qi, AN Yan-Fei   

  1. College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
  • Received:2014-07-07 Accepted:2015-01-28 Online:2015-04-01 Published:2015-04-21
  • Contact: Min-Xia LIU
  • About author:

    # Co-first authors

Abstract: <i>Aims</i>

A plant’s photosynthetic characteristics reflect its adaptive strategies to a given environment. Using pasture plants within enclosures representing communities at different stages of habitat restoration, our objective was to determine how photosynthetic characteristics vary between these different communities and what causes these differences in order to find the theoretical basis to foster rehabilitation of degraded grassland in sub-alpine meadows.

<i>Methods</i>

We predicated a succession sequence according to the species richness and the Shannon-Wiener diversity indices, the important values of the main species, and the biotype of five different communities. We measured several photosynthetic parameters including area-based leaf CO2 assimilation rate (Aarea), special leaf area (SLA), foliar nitrogen content based on mass (Nmass), photosynthetic nitrogen-use efficiency (PNUE), water-use efficiency (WUE) and chlorophyll content (SPAD) of dominant species and three common species in each succession stage. Soil water content and total nitrogen of surface soil (0-20 cm) for each community were measured as well. One-way ANOVA was used to find the differences between dominant species, while principal components analysis (PCA) was used to reveal the variation in different communities for each measured parameter.

<i>Important findings</i>

Photosynthetic traits were different among dominant species and different succession communities. The Aarea, WUE and SPAD of the dominant species decreased as succession progressed, but the Nmass, PNUE and SLA showed no consistent patterns related to succession; they varied between different functional groups. For each of the non-dominant species, the Aarea and SPAD gradually decreased as succession proceeded from initial stage to climax stage. With succession, WUE and PNUE of the non-leguminous plants (Elymus dahuricus and Geranium wilfordii) decreased while SLA and Nmass increased. However, there were no obvious changes in these parameters for the leguminous plant (Medicago sativa). Soil water content and total nitrogen increased with succession, suggesting that water content and nitrogen are two important factors affecting variation of community photosynthetic characteristics in different stages of restoration succession.

Key words: functional group, photosynthetic physiological characteristics, restoration, succession, resource-use efficiency