| Autor: |
Madin JS; Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kaneohe, Hawai'i, USA., Baird AH; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia., Baskett ML; Department of Environmental Science and Policy, University of California, Davis, CA 95616, USA., Connolly SR; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia.; School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia., Dornelas MA; Centre for Biological Diversity, Scottish Oceans Institute, University of St Andrews, St Andrews KY16 9TH, UK. |
| Abstrakt: |
Body size is a trait that broadly influences the demography and ecology of organisms. In unitary organisms, body size tends to increase with age. In modular organisms, body size can either increase or decrease with age, with size changes being the net difference between modules added through growth and modules lost through partial mortality. Rates of colony extension are independent of body size, but net growth is allometric, suggesting a significant role of size-dependent mortality. In this study, we develop a generalizable model of partitioned growth and partial mortality and apply it to data from 11 species of reef-building coral. We show that corals generally grow at constant radial increments that are size independent, and that partial mortality acts more strongly on small colonies. We also show a clear life-history trade-off between growth and partial mortality that is governed by growth form. This decomposition of net growth can provide mechanistic insights into the relative demographic effects of the intrinsic factors (e.g. acquisition of food and life-history strategy), which tend to affect growth, and extrinsic factors (e.g. physical damage, and predation), which tend to affect mortality. |
