The Determination of Floristic Diversity within Image Forest Reserve (IFR) Land Cover Types, Kilolo District, Tanzania

Abstract

Image Forest Reserve (IFR) in the Eastern Arc Mountains of Tanzania is known for its high floristic diversity within the various land cover types. The study was conducted from August to October 2019 to determine the floristic diversity in IFR. A total of 170, 20m x 40m were systematically set at an inter-plot interval of 250 m within the land cover types. Plants were identified for their botanical names, determined for A, and herbarium specimens were collected and identified later at the DSM herbarium and NHT in Arusha. Also, 2m x 5m nested subplots were set to determine shrubs and saplings, while 1m x 1m were laid for non-woody plants and tree seedlings. The Shannon index of diversity (H') and index of dominance (ID) were calculated using the H’ and ID indices; plant species evenness (J′) was also calculated. ANOVA was used to compare species composition parameters among the different land cover types. A total of 502 plant species were identified in IFR. Woodland had the largest number of plant species (38.0%) followed by trees (31.0%), shrubland and grassland (21.9%) and bare land and rocks (9.1%). The forest had the largest number of trees (115) followed by woodland (93), shrubland and grassland, and bare land and rocks had the least species diversity. The woodland had the largest relative abundance (50.3%), trailed by forest (38.9%), shrubland and grassland (8.8%), and bare land and rocks (1.9%). The H’, A, ID and J’ showed a significant difference within the forest, woodland, shrubland and grassland, and bare land and rocks. The largest plant species diversity group had an H' < 0.0195 (230 - plant species). The medium group H' ranged from ≥ 0.0195 - ≤ 0.0504 (55-plant species), and the largest H' group ranged from ≥ 0.0649 - ≤ 0.3358 with only 10 plant species. The plant species with the largest abundance had also the largest H’, and D, and hence were suggested to be the most abundant. The A, number of species (S), H’, and ID were suggested to differ significantly within the land cover types. The floristic diversity findings establish their presence and create awareness towards the conservation strategy priorities for Tanzania Forest Agency. The survey team recommends further research on biological species of IFR, participatory forest management to stimulate the sense of ownership responsibility, implementation of laws and bylaws, land cover types gaps restoration, introduction of non-woody income-generating projects, provision of regular education to the community, awareness creation on forest resources conservation, ensure permanent boundaries beacons.