Various reasons have been proposed for observed changes but yet more studies are still needed since factors for change are sometime spatially determined. For example there are limited reports which show that long term climate change may result to land use cover change due to changes in rainfall patterns and rise in temperature favouring other land uses to emerge with consequences on community livelihoods . On the other hand, made an attempt to link the impact of various environmental factors including climate change and land use and findings showed that the link is some-how indirect which suggests further investigation. On the other hand, in Tanzania a study by has revealed that there has been an increase in cultivated land due to population increase and investment in agriculture sector. In addition, a study by  found the root causes of the land use and cover changes that have taken place on the southern slope of Mount Kilimanjaro are many and multi-faced. They include demographic factors, colonial and post-independence government policies, institutional factors, legislation, as well as socio-cultural, economic and environmental factors.

Further more studies by William revealed that liberalized economic relations, such as free trade agreements and economic globalization change people’s relations to the physical environment hence induce changes in LU. The intensity and scale of land use change has increased drastically in re-cent decades, partly due to expansion of farmlands, ebb and flow table settlements and climate stresses that force agro-pastoral communities to search for virgin pastures and croplands. Basing on these trends, land use cover change and degradation of the natural resources such as land, water, forests, woodlands, grasslands and wildlife in Tanzania have been common in various ecosystems in particularly slopes of Kilimanjaro ; Usangu basin and slopes of Mount Rungwe in the volcanic region and thus exposing rural communities to vulnerable ecosystems . Although many studies have been able to establish changing land use cover types at a wide scale in various agro ecological systems. Very few of them have been able to isolate various biophysical and social factors that have contributed to such changes and where the changes observed have positive impacts. The overall aim of this study was to assess and analyse different land use cover types over the last 2 decades in two agro ecological zones of Tanzania characterised by semi humid and semi arid conditions. The study also made an at- tempt to isolate both biophysical and social factors that have played a significant role in causing land use cover change.

To discuss environmental factors that have contributed to land use cover change in case study zones one should consider both driving forces and the process it self. Various scholars have suggested that poverty, changes in policies and strategies are among the key driving forces to land use cover change . Findings showed that in all four case study villages three major wealth groups namely the rich, middle and poor groups are common and their distribution at village level ranged on average in the order of 10%, 30% and 60% for the rich, flood table the middle and the poor respectively. It was clearly noted that the majority of people are poor and most of them live under poverty and this has contributed to degradation or natural resources contributing to LUCC. It was also clearly revealed that changes and introduction of new polices in the country contributed to LUCC changes for example the introduction of villagilization policy in Tan-zania in mid 1970’s whereby people were clustered in villages called “Ujamaa” or “live close together” contributed to deforestation in new areas where they moved into for settlement and opening of new farms.Environmental change in particular changing rainfall pattern and other rain related factors are shown in Figure 3 for semi arid zone were found to have contributed directly or indirectly to LUCC. Similar observations were also reported for sub humid zone where by 81% of the total respondents indicated so. However 19% of responded were not able to clearly the pattern and trend of rainfall some perceiving that it has increased. This observation is not surprising and it could be explained in terms of existing spatial variability of rain which is common in such areas. Increasing temperature was also among factors mentioned during FGD that has contributed to LUCC in both sub humid and semi arid zones.