<P> Since 2000, the concept of landscape scale conservation has risen to prominence, with less emphasis being given to single - species or even single - habitat focused actions . Instead an ecosystem approach is advocated by most mainstream conservationists, although concerns have been expressed by those working to protect some high - profile species . </P> <P> Ecology has clarified the workings of the biosphere; i.e., the complex interrelationships among humans, other species, and the physical environment . The burgeoning human population and associated agriculture, industry, and the ensuing pollution, have demonstrated how easily ecological relationships can be disrupted . </P> <Table> <Tr> <Td> "</Td> <Td> The last word in ignorance is the man who says of an animal or plant: "What good is it?" If the land mechanism as a whole is good, then every part is good, whether we understand it or not . If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering . </Td> <Td>" </Td> </Tr> <Tr> <Td_colspan="3">--Aldo Leopold, A Sand County Almanac </Td> </Tr> </Table> <Tr> <Td> "</Td> <Td> The last word in ignorance is the man who says of an animal or plant: "What good is it?" If the land mechanism as a whole is good, then every part is good, whether we understand it or not . If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering . </Td> <Td>" </Td> </Tr>

Review of ecological concepts and principles basis of biological control