J Plant Ecol ›› 2018, Vol. 11 ›› Issue (3): 453-464.DOI: 10.1093/jpe/rtx016

• Research Articles • Previous Articles     Next Articles

Convergence of community composition during secondary succession on Zokor rodent mounds on the Tibetan Plateau

Yingbo Yang1, Jacob Weiner2, Gang Wang3 and Zhengwei Ren3,*   

  1. 1 State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, 768 Jiayuguan West Road, Lanzhou 730020, China; 2 Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg DK-1870, Denmark; 3 State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, 222 Tianshui Road, Lanzhou 730000, China
  • Received:2016-05-24 Accepted:2017-03-01 Published:2018-03-06
  • Contact: Ren, Zhengwei

Abstract: Aims The community succession theory is much debated in ecology. We studied succession on Zokor rodent mounds on the Tibetan Plateau to address several fundamental questions, among them: (i) During secondary succession, does the community composition converge towards one community state or multiple states depending on the initial colonization? (ii) Do mound communities located in different background communities exhibit different assembly trajectories?
Methods In a sub-alpine meadow, we investigated a total of 80 mound communities at several successional stages in three different background communities resulting from different management histories and compared their changes in species composition. The distribution of plant communities over time was analyzed with quantitative classification and ordination methods. The co-occurrence patterns of species were evaluated at each successional stage, and the degree of convergence/divergence among communities was obtained by calculating two beta-diversity indices.
Important findings During secondary succession, species richness of mound communities changed over time, and this change was dependent on the background community. Five life-form groups exhibited different dynamic patterns in species richness and plant cover. Community composition and the degree of species co-occurrence between communities increased over time since disturbance. There was much variation in species composition at earlier stages of succession, but communities on older mounds became more similar to each other and to their surrounding vegetation over the course of secondary succession. Post-disturbance succession of Zokor mound communities transitioned from 'multiple alternative states' to 'background-based deterministic community assembly' over time. Tradeoffs between competition and colonization, as well as the characteristics of different life-forms and mass effects within a limited species pool are the mechanisms responsible for convergence of mound communities.

Key words: multiple alternative states, background-based deterministic community assembly, sub-alpine meadow, disturbance, plant communities

摘要:
Aims The community succession theory is much debated in ecology. We studied succession on Zokor rodent mounds on the Tibetan Plateau to address several fundamental questions, among them: (i) During secondary succession, does the community composition converge towards one community state or multiple states depending on the initial colonization? (ii) Do mound communities located in different background communities exhibit different assembly trajectories?
Methods In a sub-alpine meadow, we investigated a total of 80 mound communities at several successional stages in three different background communities resulting from different management histories and compared their changes in species composition. The distribution of plant communities over time was analyzed with quantitative classification and ordination methods. The co-occurrence patterns of species were evaluated at each successional stage, and the degree of convergence/divergence among communities was obtained by calculating two beta-diversity indices.
Important findings During secondary succession, species richness of mound communities changed over time, and this change was dependent on the background community. Five life-form groups exhibited different dynamic patterns in species richness and plant cover. Community composition and the degree of species co-occurrence between communities increased over time since disturbance. There was much variation in species composition at earlier stages of succession, but communities on older mounds became more similar to each other and to their surrounding vegetation over the course of secondary succession. Post-disturbance succession of Zokor mound communities transitioned from 'multiple alternative states' to 'background-based deterministic community assembly' over time. Tradeoffs between competition and colonization, as well as the characteristics of different life-forms and mass effects within a limited species pool are the mechanisms responsible for convergence of mound communities.