Tham khảo tài liệu 'food production approaches, challenges and tasks part 4', khoa học tự nhiên, công nghệ sinh học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 46 Food Production - Approaches Challenges and Tasks Years population Density 1986 119352 1992 134821 2002 178540 2006 212628 Annual increase 4664 Table 2. Dynamics of the population size and population density during the study period Relationship between land use conversion and population density The Pearson correlation analysis indicated that change in land cover could be linked to population growth. In general there was a strong relationship between population and change in areas of cropland r2 p and dense forest land r2 p but the relationship was weak with change in area of open woodland r2 p . Significant relationships between population and areas of cropland and open woodland were observed throughout the four time series Table 3 . The higher correlations occurred in 2002 and 2006 with cropland and in 1986 and 1992 with open woodland p . However the correlations were generally low between population and dense forest land and especially it was not significant in 2002 p . Cropland Dense forest Open woodland 1986 1992 2002 2006 1986 1992 2002 2006 1986 1992 2002 2006 r2 F P- value Table 3. Coefficient of determination r2 together with F-statistic and p-values for significant Pearson correlation to examine relationship between areas of each cover type and population density. Farming practices over time and environmental implication Results from the farmers interviews revealed the presence of important migrant people in Southern Burkina Faso. They were from different origins and mostly from 14 different provinces of the central and the northern regions of the country Figure 2 . Home provinces from the central regions included Kadiogo Boulkiemde Sanguie Ganzourgou Kouritenga Oubritenga Kourweogo and
