Sustainability of home gardens

Old Pictures Bear Feeding Yosemite

Home gardens can be sustainable production systems, but usually only under low-input and low-yield conditions. For example, the home gardens of the Chagga, on Mt. Kilimanjaro (Tanzania), represent ecologically sustainable land-use systems, but their productivity is relatively low and needs to be increased if they are expected to support larger populations (Fernandes et al. 1989). Migration of young people to urban areas has disrupted the traditional transmission of the knowledge and experience...

Theories to Explain High Diversity in the Tropics

The question, Why are there so many species in the tropics is one that has intrigued scientists for almost a century. Scores of theories have been put forth to account for the increase in diversity in almost all taxa along a gradient of decreasing latitude. Pianka (1966) reviewed the major theories of the time and lumped them into six categories the time theory the theory of climatic stability the theory of spatial heterogeneity the competition hypothesis the predation hypothesis and the...