Gap creation and regenerative processes driving diversity and structure of mangrove ecosystems

Abstract

Turnover within both mangrove and terrestrial forests is driven by stand development in conjunction with factors influencing tree death and replacement at various temporal and spatial scales. Development in terrestrial forests appears comparable with that in mangroves but turnover seems to differ considerably between these broad forest types. The most important difference is in the character of small forest gaps. Gaps are common in terrestrial forests but those in mangroves rarely involve falls of large older trees in the first instance. Instead, mangrove trees usually die standing in small clusters of mixed age cohorts. Identifying a common cause for gap creation in mangroves might be important towards understanding what drives forest turnover but there is a greater need to quantify this process. Small-scale disturbance in mangrove forests is poorly quantified but preliminary evidence implies that its' importance may have been greatly under-estimated. Based on available observations, a conceptual model of mangrove forest development and gap regeneration is proposed. The model helps explain the peculiar characteristics and structure of mangrove forests and how these forests might respond to changing environmental conditions and disturbance at various landscape scales.