DAR ES SALAAM, July 25 -- AS human beings, we have a love-hate relationship with trees. On the one hand, we see trees as our friend. They give us shade, fruits, medicines, firewood and charcoal, as well as building materials.

They assist supporting rainfall and in fertilising the soil. They help with preserving water sources, preventing soil erosion, cleaning our air, cooling our surroundings and protecting the soil.

They absorb carbon dioxide, give homes to animals, and help us feel less stressed. Being near trees lowers blood pressure and calms the mind. The list of advantages is much longer.

Yet, we seem, at the same time, to hate trees, especially in developing countries. In our urban areas, clearing trees is a noble action when on...