The papers included in the book reveal the intrensic relationship between the species of plants and animals and the environment of a region. The interdependence of man on plants and animals and the symbiotic relationships in the biotic and abiotic elements of ecosystems have also been examined and it has been emphasised that in plants, animals and men some of the relationship are inherited from the past, others will be active at the present time, while others will be oriented towards the future by the complex interplay of politicoeconomic and socio-psychological factors. Each chapter of the book is self contained and written in a lucid style and give us a sense to respect all the living and non-living components of the earth's surface so that the fast changing ecosystems may retain their resilience characteristics.