Chapter 7


Terms in this set (...)

Any network of relationships among a group of components, which interact with and influence one another through exchange of matter and/or information, is referred to as
a system
A system receiving inputs and producing outputs without undergoing any changes in size or function is said to be in
dynamic equilibrium
Cattle on an open range, in some areas, may compact fragile soils while grazing. This can damage plant roots, leading to fewer, smaller plants, which may in turn cause cattle to graze more and work harder to obtain food. This is an example of a
positive feedback loop
The eutrophication that has taken place in the Gulf of Mexico and other locations appears to be due to
excess nutrients from fertilizers
The physical, abiotic components of our planet can be divided into the
lithosphere, hyrdosphere, and atmosphere
A natural ecosystem, undamaged by human activity, is
an open system of organic and inorganic materials and energy
The swamplands of extreme southern Louisiana, which contain elements of both the forests and the coast, could be called,
an ecotone
A small scetion of prairie grasses, over a year, produces enough biomass to feed insects, mice, rabbits, birds, deer, antelope, and a host of decomposers. The amount of food potentially available to the herbivores is the
net primary production
The rate at which biomass becomes available to consumers is termed
net primary productivity
The biosphere consists of the
sum of all the planet's living organisms and the abiotic portions of the environment
Ecotones are the
transitional zones between ecosystems
Examining areas from the landscape scale, termed landscape ecology, is useful because
multiple ecosystems may exist in a single area with many transitional zones
are required in large amounts for organisms to survive
Experiments done in coastal regions of oceans throughout thr world have demonstrated that
the same few micronutrients limit growth everywhere
Plants conduct photosynthesis, making glucose and other carbohydrates. To do this they need
water from the soil and carbon dioxide form the atmosphere
The largest pools of carbon in the carbon cycle are
sedimentary rock and fossil fuels
The origin of all phosphorus in biological tissues is
phosphorus weathered from rock
The origin of all nitrogen in biological tissues is
atmospheric N2 gas
Nitrogen fixation is a process that makes nitrogen available to plants by
mutualistic and free-living bacteria
Humans have dramatically altered the rate of nitrogen fixatio into forms usable by autotrophs
as we produce synthetic fertilizers and apply them to crops, lawns, and parks
The freshwater we depend on for our survival accounts for
3% of all water on Earth
Aquifers are
underground water reservoirs
By damming rivers and using methods such as flood irrigation, we are
increasing evaporation
Rock that has undergone heat or pressure that causes it to change form is called
The process of subduction
occurs when denser ocean crusts slide beneath lighter continental crusts
Human beings have dramatically altered the flux rate of nitrogen from
the atmosphere to various pools on the earth's surface