A forever young ecosystem: Light gap creation and turnover of subtropical mangrove forests in Moreton Bay, Southeast Queensland, Australia

摘要

Light gaps act as important renewal agents in mangrove forests. Light gaps progress through a number of stages starting from the death of a patch of trees through to its infill and rejuvenation of forest. These define a process of mangrove regeneration where forests naturally replace themselves over time. Light gaps in Moreton Bay mangroves were assessed to develop a greater understanding of the physical characteristics and microclimate change with adjacent canopies. Historical aerial photographs from 1978 to 2007 were analysed to reveal the dynamic processes of these mangrove forests and the role of light gap creation. The annual average number of new light gaps and the annual average number of gaps in recovery phases were calculated and used to estimate forest turnover. The average size of gaps in Moreton Bay is 84.2 m2. Average forest turnover based on gap creation decreased from 1987 to 2007. An increase in gap creation rate may be indicative of an increase in storm activity - a possible tangible effect of global climate change.