植物生态学报 ›› 2016, Vol. 40 ›› Issue (3): 187-199.doi: 10.17521/cjpe.2015.0343

• 研究论文 •    下一篇

刈割和施肥对高寒草甸物种多样性和功能多样性时间动态及其关系的影响

孔彬彬1, 卫欣华1, 杜家丽1, 李英年2, 朱志红1,*()   

  1. 1陕西师范大学生命科学学院 710119
    2中国科学院西北高原生物研究所 810008
  • 收稿日期:2015-09-08 修回日期:2016-02-06 出版日期:2016-04-11 发布日期:2016-03-25
  • 通讯作者: 朱志红 E-mail:zhuzhihong@snnu.edu.cn
  • 基金资助:
    基金项目 国家自然科学基金(31570425)

Effects of clipping and fertilization on the temporal dynamics of species diversity and functional diversity and their relationships in an alpine meadow

Bin-Bin KONG1, Xin-Hua WEI1, Jia-Li DU1, Ying-Nian LI2, Zhi-Hong ZHU1,*()   

  1. 1College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China

    2Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
  • Received:2015-09-08 Revised:2016-02-06 Online:2016-04-11 Published:2016-03-25
  • Contact: Zhi-Hong ZHU E-mail:zhuzhihong@snnu.edu.cn

摘要:

强烈扰动和环境胁迫对植物群落的物种多样性(SD)和功能多样性(FD)有重要影响, 但SD和FD随时间的变化模式及其关系至今少有研究。该研究通过对高寒矮生嵩草(Kobresia humilis)草甸为期7年(2007-2013年)的刈割(3个水平: 不刈割、留茬3 cm和留茬1 cm)和施肥(2个水平: 施肥和不施肥)控制实验探讨了SD和FD随时间的变化模式及其关系。研究结果显示: (1)刈割显著增加了SD和FD, 施肥处理则降低了SD, 对FD增加仅有微弱影响; (2)各处理群落的SD随着时间而下降, FD则随时间增加; (3)随着刈割强度的增加, SD(x)-FD(y)关系由正线性相关变为无相关, 斜率大小为slopel ≥ slopem > slopeh (下标l、m和h分别表示轻度、中度和重度扰动强度), 施肥并不会改变此关系形式和斜率; (4)刈割与施肥对SD和FD的互作效应都不显著, 且不施肥群落SD(x)-FD(y)关系的斜率也为slopel ≥ slopem > slopeh。上述结果说明, 刈割并不一定导致植物功能性状的趋同构建, 也能引发趋异构建, 而施肥引起的强烈种间竞争也并未显著增强趋异构建过程, 这与植物群落构建理论的预测不完全一致。与施肥相比, 刈割扰动是决定群落中SD-FD时间关系形式的主要因素, 并决定着SD-FD关系斜率的变化。

关键词: 刈割, 施肥, 植物功能性状, 物种多样性, 功能多样性

Abstract:
Aims Strong disturbance and environment stress have significant influence on species diversity (SD) and functional diversity (FD) in plant community. However, the changes in SD, FD and their relationships over time remain controversial. Previous studies showed that the SD-FD relationship along disturbance gradients can represent positive correlation, negative correlation and/or sigmoid curve, respectively. Our aim here is to explore the temporal dynamics patterns of SD and FD in a community experienced disturbance. Particularly, we explored how specific disturbance factor and/or disturbance intensity affect the SD-FD relationship over time.
Methods The experiment was conducted in the alpine Kobresia humilis meadow at Haibei Research Station of the Chinese Academy of Sciences with clipping (unclipping, stubbled 3 cm and 1 cm) and fertilizing (12.75 g·m-2·a-1 urea + 3.06 g·m-2·a-1 ammonium phosphate) treatments from 2007 to 2013. GLMRMANOVA regression analysis and ANCOVA were used for analyzing the effects of different treatment factors and their interaction on SD, FD, the patterns of temporal dynamics of SD and FD and their relationship over time.
Important findings SD and FD significantly increase with increasing clipping intensity. In contrast, fertilization decreased SD and increased feebly FD. During the experiment period, SD declined with time while FD increased. The SD-FD relationship was positively correlated in unclipped and moderate clipped plots, but was not correlated in heavy clipped plots. The slope of SD(x)-FD(y) relationship declined with the increase in clipping intensity. In contrast, fertilization did not change the shape and slope of the SD(x)-FD(y) relationship. The effects of the interaction of clipping and fertilization on SD and FD were not significant, and the slope changes along clipping gradients were identical in fertilized and unfertilized plots. These results suggest that clipping disturbance may induce trait divergence rather than trait convergence in this meadow community, while the strong interspecific competition resulted from fertilizing may not significantly intensify the trait divergence. These findings were inconsistent with the predictions of plant community assembly theory. Compared with fertilizing disturbance, clipping disturbance should play a more important role in shaping the SD-FD relationship.

Key words: clipping, fertilization, plant functional traits, species diversity, functional diversity