Different landforms which exist in an ecosystem, support different and specific vegetation. Ecosystem diversity is difficult to measure since the boundaries of the communities, which constitute the various sub-ecosystems are elusive. Forests perform important ecological functions such as maintaining delicate ecological and hydro- biological balances, conserving soil, controlling floods, drought and pollution. Forests also provide habitats for innumerable plants, animals and microorganisms. Agro-ecosystems tend to become poorer with more intensive cultivation, but could be a valuable local genetic resource with proper management.
There are examples where the depletion of a few species within a forest has caused a deleterious impact on the whole eco- and agro-ecosystems.Aloe veraandAsparagus racemosusspecies in addition to their medicinal properties, are also good soil binders. Removal of these plants for their underground parts has caused large scale soil erosion in Maradavally forests.
Bombax ceibacommonly known as 'Mahamara' in Maradavally forest area, has been the main shelter tree for honey bee colonies. Over exploitation of the species for its latex, has resulted in reduction of honey bee populations which are the main pollinating agents in forests as well as in cultivated fields.
Paddy growers of Maradavally village have been usingHasiosiphon eriocephalusas green manure crop which was once available in plenty in forest area. This species in addition to its nutritional value, also possesses the insecticidal properties believed to protect rice fields from the attack of insects and pests. Large scale exploitation of the species by the pesticide manufacturing companies during the last few years has deprived local people of its use.