Farmers in the Middle Hills of Nepal have a heavy dependence on tree products to sustain their agricultural systems. They manipulate tree cover on their privately-owned agricultural land - generally on terrace edges and on non-cultivated patches within the agricultural complex. Trees also occur on non-private (common) land surrounding villages, and these trees are also controlled by the farmers, even if the land is under the legal authority of the Forest Department. This paper examines changes in tree cover which are taking place on the various classes of land in a 14,000-ha catchment near Kathmandu. Comparisons were made using air photographs flown in 1972 and 1989. The area of each land-use category was determined for eight sample sites and the percentage of tree crown cover was calculated for each category. The results indicated that there was no significant shift from common land (forest/grass) to agricultural land between the two dates. The percentage of tree crown cover on the major agricultural land-use category (upland terraces) and the common land showed a significant increase between 1972 and 1989. As these two categories make up 86 percent of the sample sites, there are strong indications that the overall landscape is undergoing a steady afforestation process at the hands of the farmers.