Variation in the impact of non‐native seaweeds along gradients of habitat degradation: a meta‐analysis and an experimental test

• DOI: 10.1111/oik.02197
• Publication Date: 2015-03-30T05:15:55Z
• Authors: Laura Tamburello; Elena Maggi; Lisandro Benedett...; Giuseppe Bellistri; Alex James Rattray; Chiara Ravaglioli; Luca Rindi; Jason Roberts; Fabio Bulleri
• Keywords: 0106 biological sciences; 13. Climate action; 14. Life underwater; 15. Life on land; 01 natural sciences; Ecology, Evolution, Behavior and Systematics

Biological invasions are acknowledged among the main drivers of global changes in biodiversity. Despite compelling evidence species interactions being strongly regulated by environmental conditions, there is a dearth studies investigating how effects non‐native vary areas exposed to different anthropogenic pressures. Focusing on marine macroalgae, we performed meta‐analysis test whether and direction magnitude their resident communities varies relation cumulative impact levels. The relationship between human levels intensity emerged only for reduced subset response variables examined. Yet, was trend community biomass abundance become less negative at heavily impacted sites. By contrast, seaweed evenness tended increase with hypothesis decreasing severity invader’ impacts along gradient habitat degradation also tested experimentally regional scale comparing removal alga, Caulerpa cylindracea , assemblages rocky reefs Assemblages urban pristine site did not differ when invaded, but so C. removed. Our results suggest that, despite generally weak impacts, more can be expected stressful environments (i.e. degraded or sites), where competitive presumably driving force structuring communities. Implementing strategies controlling establishment seaweeds should be, thus, considered priority preserving biodiversity relatively areas. On other hand, control invaders sites could warranted lessen role as propagule sources. Synthesis Local stressors that severely alter biotic abiotic conditions may underpin context‐dependency biological invasions. We used an experimental examine ecological assemblages. Possibly, stronger prevail sites, mainly structured interactions. Hence, management efforts mostly directed prevent spread weak, positive most add ongoing debate rehabilitation plans.