Plant community properties predict vegetation resilience to herbivore disturbance in the Arctic

Authors

  • James D. M. Speed,

    Corresponding author
    1. Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3TZ, UK
    2. University Centre in Svalbard (UNIS), PO Box 156, N-9171 Longyearbyen, Norway
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    • Present address: Museum of Natural History and Archaeology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.

  • Elisabeth J. Cooper,

    1. Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, Tromsø University, N-9037 Tromsø, Norway
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  • Ingibjörg S. Jónsdóttir,

    1. Institute of Biology, University of Iceland, Sturlugata 7, IS-101 Reykjavík, Iceland
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  • René Van Der Wal,

    1. Aberdeen Centre for Environmental Sustainability, University of Aberdeen, School of Biological Sciences, Aberdeen AB24 3UU, UK
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  • Sarah J. Woodin

    1. Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3TZ, UK
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Correspondence author. E-mail: james.speed@vm.ntnu.no

Summary

1. Understanding the impact of disturbance on vegetation and the resilience of plant communities to disturbance is imperative to ecological theory and environmental management. In this study predictors of community resilience to a simulated natural disturbance are investigated. Responses to disturbance are examined at the community, plant functional type and species level.

2. Field experiments were set up in seven tundra plant communities, simulating disturbance based on the impact of grubbing by an increasing herbivore population of pink-footed geese (Anser brachyrhynchus). The short-term resilience of communities was assessed by comparing community dissimilarity between control plots and plots subject to three disturbance intensities based on the foraging impact of these geese. Potential for long-term recovery was evaluated across different disturbance patch sizes.

3. Resilience to disturbance varied between communities; those with higher moss cover and higher soil moisture, such as wetlands and mires, were most resilient to disturbance.

4. The wetter communities demonstrated greater long-term recovery potential following disturbance. In wetland communities, vegetative recovery of vascular plants and moss was greater in smaller disturbed patches and at the edges of patches.

5. The response of vegetation to disturbance varied with intensity of disturbance, plant community and plant species. The use of functional type classifications only partially explained the variation in species responses to disturbance across communities, thus their use in predicting community changes was limited.

6.Synthesis. The impact of disturbance is shown to be plant-community specific and related to the initial abiotic and biotic properties of the community. By showing that resilience is partly predictable, the identification of disturbance-susceptible communities is possible, which is of relevance for ecosystem management.

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