Impact of Biofuel Production on Land-Use Change: Case of Jatropha Farming, Kisarawe District, Tanzania

Modern Environmental Science and Engineering, 2017; 3 (4): 263-271Globally, agricultural sector is the major driver for land use change (LUC), in East Africa where savannas, grassland and shrubland are dominant, land previously occupied by forests is the major source of new agricultural land. The use of agricultural-based biofuels has been expanding worldwide, biofuel farming associated with LUC should be measured as the direct land use change (dLUC); when a biofuel feedstock (e.g., jatropha) directly displaces another land use. The indirect land use change (iLUC); when a productive land use displaced by a biofuel feedstock propels the conversion of native vegetation elsewhere. Few studies have been carried out in Tanzania to investigate the effect of agriculture-based biofuel on LUC, the objective of this study was to investigate the LUC resulting from jatropha production introduced in year 2009 by Sunbiofuel Company in villages within Kisarawe District, Coast Region. Remote sensing and geographical information system (GIS) techniques on Landsat multidate satellite imagery and secondary data were used to establish patterns of direct and indirect LUC. Multidate satellite images were classified and analyzed to study the LUC at three epochs; before cultivation (year 1985), immediately after starting production (year 2010) and year 2011. The study revealed a significant increase in cultivated land, a decrease in forested land and encroachment into forest reserve. It was concluded that the conversion of land used for crop production into jatropha farming caused direct and indirect LUC in the area. The outputs from the study can be used as inputs to the models and methodologies for quantifying LUC effects due to introduction/expansion of biofuels production within a district.Norwgegian Development Agenc

Dynamics of land use and land cover changes in the Pugu and Kazimzumbwi forest reserves

Urban growth contributes to land use and land cover changes in protected forest reserves primarily through conversion of peri-urban areas into settlements, agriculture and unsustainable harvesting of ecosystem services to meet demands of the population in the peri-urban and urban areas. It has been widely argued that increased anthropogenic activities have altered the forest cover for Pugu and Kazimzumbwi Forest Reserves. Nonetheless, these arguments are little supported by quantitative data. A study on the dynamics of land use and cover changes in the Pugu and Kazimzumbwi Forest Reserves therefore investigated long-term changes that have occurred as a result of human activities in the areas for the periods 1985-1995 and 1995-2010. Landsat TM and ETM+ images were used to locate and quantify the changes using remote sensing and GIS techniques. Perceptions of local people on historical changes and drivers for the changes were also collected from three neighbouring villages and integrated in the assessment. The analysis was augmented by statistical analysis of 30 years historical rainfall and temperature records from Dar es Salaam and Kisarawe Climatic Stations. The study revealed remarkable decline in closed forest area in the latter period at -1.7 ha/year for Kazimzumbwi Forest Reserve (KFR) and -1.53 ha/year for Pugu Forest Reserve. The woodland variably decreased during the 1985 and 1995 period for both PFR and KFR but increased for PFR and decreased for KFR in the latter period. Unlike for closed forest and woodland, the cultivated land and built up area increased between the two periods for both forests reserves, while other covers variably increased or decreased between the years. The peoples’ perceptions and drivers for the changes are presented and discussed together with the land use and land cover change analysis. The study concludes that, there has been remarkable changes in land use and cover in the catchment and these require concerted actions to reverse the changes and enable the forest reserves contribute to REDD initiatives.CCIA