Plant species composition, diversity and utilization impacts on the miombo woodland ecosystems of Hanang district, Tanzania
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Date
2008
Authors
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Journal ISSN
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Publisher
Sokoine University of Agriculture
Abstract
Miombo woodlands constitute one of the most extensive forest vegetation types in
Africa. This complex ecosystem provides vital products and services to the
livelihood systems of millions of rural and urban dwellers. The study was carried
out in four
forest reserves to assess plants species composition, diversity.
dominance, human utilization and its impacts on the miombo woodland of Hanang
District, Tanzania. Ecological data were collected through forest inventory while
socioeconomic data were collected through household questionnaire survey. Data
from forest inventories were analyzed in MS EXCEL program to compute species
richness, dominance and diversity. Descriptive statistics in cross tabulation were
carried out to analyze socioeconomic data using Statistical Package for Social
Sciences (SPSS) software. A total of 69 tree species belonging to 22 families were
identified. The average Shannon-Wiener index of diversity (//’) for all the forests
reserves were 3.3 and 0.1 respectively, having high species diversity in all forests.
Based on the species Importance Value Index (IVI), Julbernardia globiflora was the
most dominant in three of the four forest reserves while Brachystegia spiciformis
was most dominant in the fourth reserve in the district. A total of 12 species were
common in all forest reserves and therefore widespread. A total of 49 tree species
are utilized by the surrounding local communities for different purposes. Major
products utilised from the woodlands include firewood (95%), charcoal (58%), poles
(56%) and timber (5%). Harvesting of various tree species for different purposes
were the most common human impacts observed in the area. It is concluded that.
given the variation in species diversity and dominance between individual forest
reserves, management strategies should be site specific so as to balance both
ecological diversity of the individual forest and local uses in a sustainable manner. It is recommended that, there is a need to promote and encourage alternative activities
such as improved cooking stoves, biogas use, beekeeping and tree planting that will
aim at reducing future utilization pressure of miombo woodland in the district.
Enrichment planting with indigenous plant species in those forested areas where
substantial tree removal was evident as well as increase law enforcement to protect
the forest reserves is also recommended.
Description
Dissertation
Keywords
Miombo woodlands, Hanang District, Miombo-ecosystems, Forestry, Plant species