¥Open-system self-regulating EcosystemsÕ overall stability ÒdynamicallyÓ maintained by 3 chief mechanisms:
–Controlling the rate of chemical and
material cycling with the ÒwaterÓ
system
–Controlling the rate of energy flow
through the ÒwaterÓ
system
–Maintaining a diversity of species
& food webs so that system stability is not affected seriously by the loss of some food
web links and/or species
¥Human-induced alterations of ÒnaturalÓ water systems
–Disruption of essential
material/nutrient cycle:
¥Changing the rate of cycling by
material overloads or leaks in the system
¥Breaking the cycle
¥Introduction of human-made chemicals
into the water, especially those with no natural decomposition chain
–Disruption of energy flow(s)
¥Entropy or heat build-up in the
system by consumption of too much energy by human society
¥Changing properties and/or
composition of the atmosphere leading to an increase or decrease in the solar energy input
involved in hydrological cycle
¥Altering drainage systems (quality,
quantity, direction of flow, etc.)
–Disruption of the ecosystem by
destruction of species diversity and/or the food web
–