植物生态学报 ›› 2013, Vol. 37 ›› Issue (5): 384-396.doi: 10.3724/SP.J.1258.2013.00040

• 研究论文 • 上一篇    下一篇

高寒草甸对刈割、施肥和浇水发生响应的最优植物性状集和功能型

李燕, 朱志红*   

  1. 陕西师范大学生命科学学院, 西安 710062
  • 收稿日期:2012-12-09 修回日期:2013-03-25 出版日期:2013-05-01 发布日期:2013-05-16
  • 通讯作者: 朱志红 E-mail:zhuzhihong@snnu.edu.cn
  • 基金资助:

    国家自然科学基金

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

LI Yan and ZHU Zhi-Hong*   

  1. College of Life Sciences, Shaanxi Normal University, Xi’an 710062, China
  • Received:2012-12-09 Revised:2013-03-25 Online:2013-05-01 Published:2013-05-16
  • Contact: ZHU Zhi-Hong E-mail:zhuzhihong@snnu.edu.cn

摘要:

基于植物性状和功能型的特征变化对于研究植被动态和生态系统功能变化具有重要意义。通过在高寒矮嵩草(Kobresia humilis)草甸为期5年(2007–2011年)的刈割(不刈割、留茬3 cm、留茬1 cm)、施肥(施肥、不施肥)和浇水(浇水、不浇水)控制实验, 采用递归算法(recursive algorithm)和多元回归分析筛选对模拟放牧发生响应的最优植物性状集和响应功能型, 以及影响群落生产力变化的作用功能型。研究结果显示: (1)在不施肥不浇水、仅施肥、仅浇水和既施肥又浇水4种条件下的最优植物性状集不同, 它们分别是叶缘形状-株高-叶干质量-比叶面积、生活周期-株高-叶干质量-比叶面积、生活周期-叶片叶绿素含量-叶表面结构-株高-叶干质量-比叶面积和繁殖结构-叶缘-株高。其中, 株高、叶干质量和比叶面积是对刈割和土壤资源变化更为敏感的植物性状。(2)在这4种处理条件下, 共获得14个最优响应功能型和4个作用功能型。作用功能型对群落生产力变异的解释能力在50.3%–86.4%之间。(3)最优响应功能型和作用功能型分别占功能型总数的70%和20%。作用功能型占最优响应功能型的28.5%, 两者间仅存在部分重叠。上述结果说明, 植物功能性状和功能型变化能够准确地反映植被的放牧响应和生态系统功能变化, 但是不同资源条件下群落的最优响应性状集和功能型不同。作用功能型是同时反映植被放牧响应和生态系统功能变化的最优功能型。

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.