Sprouting, succession and tree species diversity in a South African coastal dune forest

Background

This study examines the role of sprouting in the maintenance of plant diversity where prevailing disturbance frequency and severity allows, specifically, in the coastal dune forest of Kwazulu-Natal. 

Goals & Methods

The researcher investigates four hypotheses: 1. Compared with site factors (slope and stem leaning), succession is more important in explaining species composition; 2. The incidence of basal sprouting decreases with advancement of succession whereas that of trunk sprouting decreases with advancement of succession; 3. Tree species diversity decreases with advancement of succession; and 4. Basal sprouting is associated with low species diversity. Data was collected from 42 20x20m plots - slope angle, canopy cover and height, dbh of the main stem and all the stems attached to the main stem at or close to the ground, branching height, nearest neighbor distance, stem leaning from normal vertical of the main stem and the number of live sprouts above and below 1.3m - the top ten tree species in the study were assessed.

Conclusions & Takeaways

The results suggest that basal sprouts are important on early successional sites thus, enabling trees to maintain multiple stems and to replace damaged stems; while trunk sprouts are important on late successional sites thus facilitating the persistence of established stems.