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Certain, Gregoire; Barraquand, Frederic; Gardmark, Anna. |
1.Multivariate autoregressive (MAR) models are an increasingly popular technique to infer interaction strengths between species in a community and to predict the community response to environmental change. The most commonly employed MAR(1) models, with one time lag, can be viewed either as multispecies competition models with Gompertz density‐dependence or, more generally, as a linear approximation of more complex, nonlinear dynamics around stable equilibria. This latter interpretation allows for broader applicability, but may come at a cost in terms of interpretation of estimates and reliability of both short‐ and long‐term predictions. 2.We investigate what these costs might be by fitting MAR(1) models to simulated two‐species competition,... |
Tipo: Text |
Palavras-chave: Forecasting; Interaction strength; MARSS; Multivariate autoregressive models; PRESS perturbation. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00439/55085/56521.pdf |
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Cognat, Mathis; Ganthy, Florian; Auby, Isabelle; Barraquand, Frederic; Rigouin, Loic; Sottolichio, Aldo. |
The relative impact of light, depth, hydrology, hydrodynamics, sediment and nutrients on growth of the seagrass Zostera noltei was investigated in Arcachon Bay, where the extent of seagrass beds has been decreasing for 20 years. A comprehensive multi-parameter survey of 9 sites was conducted monthly over one year. A three-parameter logistic growth model was fitted to biomass data to unravel the relative contributions of environmental factors on seagrass growth. The present study highlights the fact that, in addition to the dominant positive effect of light on plant growth, the hydrological and hydrodynamic parameters were important drivers for Z. noltei growth at the scale of the whole Bay. At the scale of individual sites, other factors such as macroalgal... |
Tipo: Text |
Palavras-chave: Physical parameters; Light; Hydrodynamics; Adaptation; Statistical growth model. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00451/56229/57789.pdf |
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