Comparing the stability of successional transient models in kelp forests and barrens (south-east Pacific): Implications for conservation monitoring
Ortiz, Marco;Uribe, Roberto A.
Univ Catolica Norte, Fac Ciencias Mar, Dept Biol Marina, Coquimbo, Chile.
Univ Antofagasta, Fac Ciencias Mar & Recursos Biol, Inst Antofagasta, Inst Ciencias Nat AvH, Antofagasta, Chile.
Lab Costero Huanchaco IMARPE, Area Macroalgas & Biodiversidad, Huanchaco, La Libertad, Peru.
conservation;ecological succession;management;stability;transient models
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS
Ecological stability based on statistical variability was contrasted with the asymptotical local stability of transient states during successional changes in community structure in kelp forests and barren grounds. Simplified semi-quantitative ecological models with different levels of complexity were constructed to represent transient successional states in kelp and barrens, and Routh-Hurwitz's criteria and Levins' criterion of local stability were also estimated. The results suggest that ecological stability based on statistical variation does not match local (mathematical) stability, since although successional changes in kelp exhibited less variability (measured as percentage coefficient of variation), barren beds were more locally stable. The local stability criteria used in the current work could be a suitable technique for evaluating the likelihood of transient ecological states to resist or change, since it considers states at equilibrium to maintain their properties only against small disturbances. These outcomes are relevant because the natural alternation between kelp and barrens could be disrupted by the intensive harvest of kelp species carried out over the last 10 years on the central-north Chilean coast and in other temperate ecosystems. Additionally, the negative effects of harvesting kelp species could have a synergetic relationship with other drivers such as climate change and coastal pollution. Thus, strict policy managements to limit the kelp harvest are deeply encouraged. A monitoring programme for assessing the current conditions of benthic-pelagic ecosystems along the Chilean coast is also required.