Effects Of Sand Mining On Land Degradation And Plant Species Diversity: A Case Study Of North B District Of Unguja Region, Zanzibar

ABSTRACT

A study was carried out to assess effects of sand mining on land degradation and plant species diversity in North „B‟ district, Zanzibar based on specific objectives to: (1) investigate community perception on sand mining, (2) asses the impact of sand mining on socio-economic activities among small holder farmers,(3) determine effect sand mining on land degradation. The study also aimed (4) to determine effect of sand mining on plant species biodiversity, (5) to identify important strengths, weaknesses, opportunities and challenges (SWOT) on sustainable mining and (6) to investigate efforts undertaken among local communities to overcome ecological threats due to sand mining. Structured and semi-structured questionnaires were enumerated among 120 respondents from three villages, with intense sand mining namely, Donge, Kazole and Pangatupu compared to Mahonda village which was used as a positive control. Socio-economic survey was coupled with interviews and panel discussions. Effect of sand mining on plant species diversity was assessed using 18 square sample plots of 20 m x 20 m. Data on the effect of sand mining on land degradation were analyzed using Statistical Package for Social Services (SPSS). Sand mining was attributed land degradation (85.6%), low agricultural productivities (64.4%), shortage of agricultural land (55.8%) and soil erosion (38.8%). Data on plant species were analysed using Statistical Analytical System (SAS) and result were: Index of dominance (C) of shrubs species ranged from 0.14- 0.19 and tree species range from 0.11- 0.15.Shannon-Weiner index diversity (H‟) of shrubs species ranged from 1.18- 1.98 and tree species ranged from 2.08- 2.3. Sand mining with associated with decreased plant species diversity as indicated by 0.12 shrub species, 0.10 tree species index of dominance and Shannon - Weiner index of diversity 2.18 vi shrub species, 2.69 tree species for Mahonda non – mined site. The study concludes that, to identify strengths that people have knowledge on conservation especial on land degradation and plant species. It is recommended that, the government in collaboration with other stake holders should make special effort to mobilize the community to participate in controlling campaign against adverse effects of sad mining