Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (5): 384-396.DOI: 10.3724/SP.J.1258.2013.00040

Special Issue: 青藏高原植物生态学:生态系统生态学

Previous Articles     Next Articles

Optimal plant traits and plant functional types responsible to clipping, fertilizing and watering in alpine meadow

LI Yan,ZHU Zhi-Hong()   

  1. College of Life Sciences, Shaanxi Normal University, Xi’an 710062, China
  • Published:2013-05-16
  • Contact: ZHU Zhi-Hong

Abstract:

Aims Our objective was to study vegetation dynamics and changes in ecosystem functions based on plant traits and characteristics of plant functional types (PFTs).
Methods A field manipulation experiment with a split-plot design was conducted in alpine meadow at the Haibei Research Station of the Chinese Academy of Sciences from 2007 to 2011. Three clipping levels (stubbled 1 cm, 3 cm and unclipped) were used on the whole plot and subplots were treated with or without fertilizer and watering. The recursive algorithm and multivariate analysis were implemented to search for optimal trait subsets and plant response types (PRTs), which could response to experimental treatments, and to identify plant effect types (PETs) impacting the aboveground net primary productivity of community.
Important findings Under each of four resource conditions, i.e., unfertilized and unwatered (NFNW), fertilized only (F), watered only (W) and fertilized and watered (FW), the optimal response trait subsets were different, i.e., leaf margin-plant height-leaf weight-specific leaf area, life cycle-plant height-leaf weight-specific leaf area, life cycle-chlorophyll content-leaf surface-plant height-leaf weight-specific leaf area, and propagative organ-leaf margin-plant height, respectively. Of these responses, plant height, leaf weight and specific leaf area were more sensitive to treatments than others. Under the resource conditions, we found 14 optimal PRTs and four PETs in all of the PFTs. These PETs can explain 50.3%-86.4% of variation in productivity. The optimal PRTs and the optimal PETs account for 70% and 20% of all PFTs. PETs account for 28.5% of PRTs, therefore, there was partial overlap between PETs and PRTs. These results indicate that both vegetation response to grazing disturbance and ecosystem functioning changes could be accurately reflected by easily measurable plant functional traits. However, the optimal trait subsets and PFTs could be different depending on when the heterogeneity of resources is taken into account. PETs are the optimal PFTs reflecting vegetation response to grazing disturbance, but also changes in ecosystem functioning.

Key words: clipping, fertilizing, functional effect type, functional response type, plant functional trait, watering