植物生态学报 ›› 2019, Vol. 43 ›› Issue (1): 16-26.doi: 10.17521/cjpe.2018.0119

• 研究论文 • 上一篇    下一篇

漓江河岸带植物功能性状变异与关联

梁士楚,刘润红,荣春艳,常斌,姜勇()   

  1. 广西师范大学珍稀濒危动植物生态与环境保护教育部重点实验室/广西师范大学生命科学学院, 广西桂林 541006
  • 收稿日期:2018-05-20 接受日期:2018-12-08 出版日期:2019-01-20 发布日期:2019-04-25
  • 通讯作者: 姜勇 E-mail:yongjiang226@126.com
  • 基金资助:
    国家“十二五”科技支撑计划(2012BAC16B03);国家自然科学基金(31860124)

Variation and correlation of plant functional traits in the riparian zone of the Lijiang River, Guilin, Southwest China

LIANG Shi-Chu,LIU Run-Hong,RONG Chun-Yan,CHANG Bin,JIANG Yong()   

  1. Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Normal University/College of Life Science, Guangxi Normal University, Guilin, Guangxi 541006, China
  • Received:2018-05-20 Accepted:2018-12-08 Online:2019-01-20 Published:2019-04-25
  • Contact: JIANG Yong E-mail:yongjiang226@126.com
  • Supported by:
    Supported by the National Science and Technology Pillary Program during the Twelfth Five-year Plan Period of China(2012BAC16B03);the National Natural Science Foundation of China(31860124)

摘要:

研究植物功能性状随环境梯度的变异和关联格局, 对于认识不同环境梯度下群落构建和植物适应型具有重要意义。该研究以漓江河岸带不同河段植物群落为研究对象, 调查了研究区内36个样方的物种组成, 测量了样方内42种木本植物的叶面积(LA)、比叶面积(SLA)和木材密度(WD)的功能性状值, 并运用性状梯度分析法对3个功能性状进行群落内(α组分)和群落间(β组分)组分分解及相关性分析。结果表明: (1)群落平均LA表现为中游最小且和下游差异显著, 群落平均WD则表现为中上游显著高于下游, 群落平均SLA在两两河段间均差异显著。(2)不同河段的3个植物功能性状β组分差异显著且实际观测值均小于随机模拟的零模型分布, 但α组分在河岸带不同河段均差异不显著且3个功 能性状的α组分分布范围均小于β组分, 说明在河岸带不同河段的群落构建过程中环境筛选的作用要大于群落内种间的相互作用。(3)性状SLALA在群落间和群落内呈现出实际观测和随机模拟的相关性均较低, 暗示了LASLA各自代表了植物在不同生态策略上的维度; 但SLAWD实际观测值和随机模拟值呈现出较强的负相关关系, 暗示这2个性状对于环境筛选表现出较高的整体趋同适应性, 体现了植物功能性状对群落间环境变异的依赖性大于群落内种间相互作用的依赖性。

关键词: 漓江, 河岸带, 功能性状, 尺度变异, 性状梯度分析, 冗余分析, 相关性, 零模型

Abstract:
Aims Patterns of variation in plant functional traits and the correlation among them are important for understanding species coexistence and the maintenance of biodiversity. Our objectives in this study were to understand how variation and correlation of plant functional traits, at both the species and community levels, influence 1) plants adaptation to changing environments, and 2) the mechanisms of community assembly.
Methods We investigated species composition of riparian plant communities in 36 plots along the longitudinal gradient (represented by upstream, midstream, downstream) of the Lijiang River, Guilin, Southwest China. We measured three functional traits for 42 woody plant species: leaf area (LA), specific leaf area (SLA), and wood density (WD). For each plant community, we calculated 1) species abundance-weighted mean community trait values, and 2) species-level mean trait values. For each of these calculations, we used trait-gradient analysis to partition the three traits into alpha and beta components. We then conducted Pearson correlations to analyze the relationships among the three traits along the longitudinal gradient. Finally we tested the strength of environmental filtering using a null model that generates randomly assembled communities with species richness given by observed values.
Important findings The species abundance-weighted mean community value of LA was lowest in the midstream communities, which was significantly different from that in the downstream communities. The mean community value of WD for midstream and upstream communities was significantly higher than that for downstream communities. Mean community value of SLA was significantly different among the three reaches. The beta components of the three functional traits significantly differed among the three reaches and had observed values that are, on average, lower than simulated values. However, alpha components for all three traits were not significantly different among the three reaches and had consistently lower variation than beta components. This implies that the variation in the mean community trait value across plots was greater than trait variation between species within plots. The observed and simulated values of the alpha components for both LA and SLA were weakly correlated with each other within and among communities, which suggests that there are independent axes of differentiation among coexisting species. On the other hand, comparisons between observed and simulated values indicated that significantly negative correlations between SLA and WD were largely the result of strong environmental filters. Finally, these results imply that variation of plant functional traits is greater among communities than within communities.

Key words: Lijiang River, riparian zone, functional traits, scale variation, trait-gradient analysis, RDA ordination, correlation, null model