universal symptoms of poor health or damage to system integrity: The buildup of waste material and the proliferation of simpler life forms (bacteria, insects) that thrive on it - but no consequent population growth in those species that normally prey on them; The loss of keystone species, often a top predator, causing smaller carnivores to proliferate, very often overstressing herbivore populations; A higher rate of species mortality due to disease rather than predation, climate, or food scarcity; The migration of whole species into or out of a region, contrary to established or historical patterns; The proliferation of a bioinvader or even a monoculture where previously a more biodiverse species range existed. Some practices such as organic farming, sustainable forestry, natural landscaping, wild gardening or precision agriculture, sometimes combined into sustainable agriculture, are thought to improve or at least not to degrade ecological health, while still keeping land usable for human purposes. This is difficult to investigate as part of ecology, but is increasingly part of discourse on agricultural economics and conservation. Ecotage is another tactic thought to be effective by some in protecting the health of ecosystems, but this is hotly disputed. In general, low confrontation and much attention to political virtues is thought to be important to maintaining ecological health, as it is far faster and simpler to destroy an ecosystem than protect it—thus wars on behalf of ecosystem integrity may simply lead to more rapid despoliation and loss due to competition. Deforestation and the habitat destruction of deep-sea coral reef are two issues that prompt deep investigation of what makes for ecological health, and fuels a great many debates. The role of clearcuts, plantations, and trawler nets is often portrayed as negative in the extreme, held akin to the role of weapons on human life. (See Human impact on the environment.) See also Ecosystem health EcoHealth Index of biological diversity Natural capital Normative science Overconsumption Overexploitation Resilience (ecology) Scorched earth References Costanza R, Norton BG and Haskell BD (1992) Ecosystem health: new goals for environmental management, Island Press, . Center for Ecological Health Research University of California, Davis. It is one of four environmental research centers established in 1991 by the U.S. Environmental Protection Agency (R819658 & R825433) Environmental health