Browsing by Author "Kumar, L."

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    Dynamics of forest cover conversion in and around Bwindi impenetrable forest, Southwestern Uganda
    (Journal of Applied Sciences and Environmental Management, 2011) Twongyirwe, R; Majaliwa, J. G. M.; Ebanyat, P.; Tenywa, M. M.; Sheil, D.; Heist, M. V.; Oluka, M.; Kumar, L.
    Forest cover has been converted to agricultural land use in and around the protected areas of Uganda. The objectives of this study were; to examine the dynamics of forest cover change in and around Bwindi impenetrable forest between 1973 and 2010 and to identify the drivers of forest cover change. The trend in forest cover change was assessed by analyzing a series of orthorectified landsat imageries of 1973, 1987 and 2001 using unsupervised and supervised classification. Land use/cover map for 2010 was reconstructed by analyzing 2001 image, validated and/or reconstructed by ground truthing, use of secondary data and key informant interviews. A series of focused group discussions and key informant interviews were also used to identify drivers of land use/cover change. Policies and institutional arrangements that could have affected forest cover change for the studied time period were also identified. Results showed that protected forest and woodlot in unprotected area had declined by 7.8% and 70.7% respectively as small scale farming and tea plantations had increased by 13.9% and 78.3% respectively between 1973 and 2010. The conversions were attributed to land use pressure due to population growth, change in socio-economic conditions and institutional arrangements. The severe loss of woodlot outside the protected area not only poses a potential threat to the protected forest but also calls for intervention measures if efforts to mitigate climate change impacts are to be realized
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    Variability Of Soil Organic Carbon Stocks Under Different Land Uses: A Study In An Afro-Montane Landscape In Southwestern Uganda
    (Geoderma, 2013) Twongyirwe, R.; Sheil, D.; Majaliwa, J.G.M.; Ebanyat, P.; Tenywa, M.M.; Kumar, L.
    We explore and compare quantities and patterns of Soil Organic Carbon (SOC) in protected forest and neighboring land around Bwindi Impenetrable National Park (a mountain protected area in Southwestern Uganda). We assessed paired sites of natural forest and major land uses (potato, tea and grazing lands) converted between 1973 and 2010. These pairings were replicated at three altitudinal zones. Plots (20m by 50m) were demarcated within each site. Five composite soil and core samples were obtained from 0 to 15cm (top-soil) and 15–30cm (sub-soil) at each plot. In total, 192 composite soil and core samples were collected. Within forest we found marked site to site variation in SOC from 54.6 to 82.6Mg/ha. There was a tendency for higher SOC in converted land, associated with higher bulk density suggesting quality based land use selection with forest left on inferior soils. Cultivation, landscape position, slope and sampling depth were all significantly (P<0.05) related to variation in SOC stocks following forest conversion but time since conversion had no detectable impact. Interestingly, there was no significant relationship between SOC in the top and sub-soils. Higher SOC is largely determined by higher bulk density. The large SOC stocks in these afro-montane soils are less predictable and more persistent than anticipated.