tailieunhanh - OCEANOGRAPHY and MARINE BIOLOGY: AN ANNUAL REVIEW (Volume 46) - Chapter 2

Tóm tắt khả năng phục hồi sinh thái các rạn san hô phụ thuộc rất nhiều vào khả năng của các quần thể san hô để thiết lập lại trong môi trường sống bị chi phối bởi macroalgae. Các rạn san hô trên toàn cầu đang chịu áp lực ngày càng tăng nhanh chóng từ các hoạt động của con người, | EFFECTS OF BENTHIC ALGAE ON THE REPLENISHMENT OF CORALS AND THE IMPLICATIONS FOR THE RESILIENCE OF CORAL REEFS CHICO L. BIRRELL1 LAURENCE J. MCCOOK1 2 BETTE L. WILLIS1 GUILLERMO A. DIAZ-PULIDO3 1ARC Centre of Excellence for Coral Reef Studies and School of Marine and Tropical Biology James Cook University Townsville QLD 4811 Australia E-mail CLBirrell@ 2Great Barrier Reef Marine Park Authority Townsville 4810 QLD Australia and Pew Fellowships Program in Marine Conservation Corresponding Author E-mail 3ARC Centre of Excellence for Coral Reef Studies and Centre for Marine Studies The University of Queensland Brisbane St. Lucia 4072 QLD Australia E-mail Abstract The ecological resilience of coral reefs depends critically on the capacity of coral populations to re-establish in habitats dominated by macroalgae. Coral reefs globally are under rapidly increasing pressure from human activities especially from climate change with serious environmental social and economic consequences. Coral mortality is usually followed by colonisation by benthic algae of various forms so that algae dominate most degraded and disturbed reefs. The capacity of coral populations to re-establish in this algal-dominated environment will depend on direct and indirect impacts of the algae on the supply of coral larvae from remnant adults on settlement of coral larvae and on the post-settlement survival and growth of juvenile corals. The effects of benthic algae on coral replenishment vary considerably but the thick mats or large seaweeds typical of degraded reefs have predominantly negative impacts. Some algae mostly calcareous red algae may enhance coral settlement on healthy reefs. Algal effects on coral replenishment include reduced fecundity and larval survival pre-emption of space for settlement abrasion or overgrowth of recruits sloughing or dislodgement of recruits settled on crustose algae and changes to habitat