Among-site variability in the stochastic dynamics of East African coral reefs

PeerJ

article

Katherine A. Allen¹  John F. Bruno³  Fiona Chong¹  Damian Clancy⁴  Tim R. McClanahan⁵  Matthew Spencer¹  Kamila Żychaluk⁶ 

[1] School of Environmental Sciences, University of Liverpool;Institute of Integrative Biology, University of Liverpool;Department of Biology, University of North Carolina at Chapel Hill;School of Mathematical and Computer Sciences, Actuarial Mathematics and Statistics, Heriot-Watt University;Wildlife Conservation Society;Department of Mathematical Sciences, University of Liverpool

关键词: Vector autoregressive model;    State-space model;    Stochastic dynamics;    Community composition;    Spatial variability;    Temporal variability;    Coral reef;    Bayesian statistics;   

DOI  :  10.7717/peerj.3290

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Coral reefs are dynamic systems whose composition is highly influenced by unpredictable biotic and abiotic factors. Understanding the spatial scale at which long-term predictions of reef composition can be made will be crucial for guiding conservation efforts. Using a 22-year time series of benthic composition data from 20 reefs on the Kenyan and Tanzanian coast, we developed Bayesian vector autoregressive state-space models for reef dynamics, incorporating among-site variability, and quantified their long-term behaviour. We estimated that if there were no among-site variability, the total long-term variability would be approximately one-third of its current value. Thus, our results showed that among-site variability contributes more to long-term variability in reef composition than does temporal variability. Individual sites were more predictable than previously thought, and predictions based on current snapshots are informative about long-term properties. Our approach allowed us to identify a subset of possible climate refugia sites with high conservation value, where the long-term probability of coral cover ≤0.1 (as a proportion of benthic cover of hard substrate) was very low. Analytical results show that this probability is most strongly influenced by among-site variability and by interactions among benthic components within sites. These findings suggest that conservation initiatives might be successful at the site scale as well as the regional scale.

【 授权许可】

CC BY