Spatial Dynamics and Structure of Human Disturbed Mangrove Forests in Contrasting Coastal Communities in Eastern Africa

Abstract

The spatial dynamics and structure of mangrove forests in peri-urban, rural and rural island settings in Mozambique was investigated to test the hypothesis that peri-urban forests are more impacted. LandSat images from 1991, 2002 and 2013 were analysed for changes in area cover and forest structural data were collected in the field. At the peri-urban site, mangrove cover increased by 22.7%, while at the rural site 23.2% were lost. The small area of the rural island was not assessed, but losses are expected given the high density of stumps. All forests are structurally small, with height and diameter of species varying significantly among sites (p < 0.001). The forest complexity index varied from 1.61 (rural island), to 0.90 (peri-urban) and 0.39 (rural). The communities harvested all diameter classes at the rural island, while class 5.1–8 cm was preferred at the peri-urban and rural sites. The proportion of stumps:live trees were 1:11 (peri-urban site); 1:9 (rural) and 1:4 (rural island). The proportions of regenerating classes were 16:4:1 (peri-urban); 76:16:1 (rural) and 8:1:0 (rural island). This study provided important insights to mangrove forest structure and uses in an understudied region and showed that management plans are required at all sites for sustainable use.