The impact of land cover change on floristic diversity and aboveground carbon stock in image forest reserve, Tanzania

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Date
2021-11
Journal Title
Journal ISSN
Volume Title
Publisher
university of Dar es Salaam
Abstract
Evaluating the impact of land cover change on floristic diversity and above ground carbon stock (AGtC ha-1) is important for awareness vegetation condition. A study was done in 2019 to assess the impact of land cover change on floristic diversity and aboveground carbon stock in Image Forest Reserve (IFR). Satellite images from Landsat 5 (TM) and Landsat 8 (OLI) for 1990, 2004, and 2018 were used for image processing of visual and digital image using ArcGIS 10.5 software. Plots of 20 m x 40 m were set at an inter-plot distance of 250 m, on which trees with a diameter ≥ 5 cm were measured. Nested plots of 2 m x 5 m were set for assessing shrubs, saplings, and poles, while 1 m x 1 m subplots were established to assess herbaceous plants, and tree seedlings. Anthropogenic activities were assessed and recorded on a scale of 1-5, where 1-20% was scaled as one (1); 21-40% (2); 41-60% (3); 61-80% (4); ≥ 81% (5). Shannon Wiener Diversity Index (H') was used to calculate diversity index, and Simpson index (Pi2) was used to calculate index of dominance. Tree density, relative density, and basal area were calculated. The identified land covers were forest, woodland, shrubland and grassland, and wooded grassland. Results revealed that from 1990 - 2004 woodland decreased by 577.89 Ha, shrub land and grassland decreased by 830.43 Ha, and wooded grassland decreased by 323 Ha, while forest cover increased by 1,731.96 Ha. Between 2004 - 2018 woodland increased in size by 572.31 Ha, shrub land and grassland cover (831.87 Ha), wooded grassland (313.47 Ha), while forest decreased in size by 1,717.56 Ha. The identified land cover change drivers were logging for timber, grazing, wildfires, encroachment, and snaring. A total of 502 plant species were identified, and woodland had the highest plant species diversity followed by other land covers. Forest had the highest AGtC ha-1 of all others. Tree regeneration varied significantly within the land cover types. The tree regenerants density was higher in forest followed by woodland, and wooded grassland was the least. Trees with a diemeter > 40 diameter had the highest basal area. This information that will enhance conservation strategy of IFR reflected from how land cover types have changed, diversity potential, carbon stocks, trees density and regeneration. Alternative income generating projects, participatory forest management, establishment of woodlots at local communities’ homesteads, and education should be applied to sustain the forest reserve.
Description
available in print form, East Africana Collection, Dr. Wilbert Chagula Library,(THS EAF QK411.T34K396)
Keywords
Plant diversity, Land use, Forest reserve, Tanzania
Citation
Kayombo, C. J. (2021) The impact of land cover change on floristic diversity and aboveground carbon stock in image forest reserve, Tanzania, University of dar es salaam, Dar es salaam
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