Mangrove community recovery potential after catastrophic disturbances in Bangladesh

Publikations-Art

Zeitschriftenbeitrag

Autoren

Sheikh Harun-or-Rashid, Kruse, M. , Böcker, R.

Erscheinungsjahr

2009

Veröffentlicht in

Forest Ecology and Management

Verlag

www.Elsevier.com

Band/Volume

257 (2009)/

Seite (von - bis)

923-930

Schlagworte

Mangrove

The objective of this study was to compare the variation in the soil seed banks and the aboveground vegetation in relation to three habitats, i.e., swamp forests, grassland and sand dunes within the Sundarbans mangrove forests of Bangladesh. We collected vegetaion data (species and their percentage cover) by using quadrat sampling: 10m x10m for swamp forest an 5m x 5m for grassland and sand dunes. We estimated the density of viable seeds of species in the sand bank by counting germinants from soil cores in a germination chamber. Species richness and composition on both aboveground vegetation and the soil banks differed significantly among habitats. We identified a total of 23 species from the soil seed bank. Of these, two were true mangrove species and the remaining were non-mangrove species, including halophytic grasses, herbs and mangrove associate species. Our results confim that mangrove species do not possess a persistent soil seed bank. the presence of high-desity non-mangrove andassociated mangrove species in the soil seed bank implies that after frequent catastrophic disturbances which limit incoming propagules from adjacent forest stand, large canopy gaps can easily become invaded by non-mangrove and mangrove associate species. This would result in the formation of a cover of non-mangrove species and cryptic ecological degradation in mangrove habitats. We suggest that forst managers should actively consider gap plantations with mangrove species in the large canopy gaps created after catastrophic distrurbances to counteract the invasion of non-mangrove species and cryptic ecological degradation.