Any network or relationships among a group of components, which interact with and influence one another through exchange of matter and/or information, information is referred to as
Prairie dogs constantly dig though the soil, making new burrows. They est the grasses, roots and all. This probably contributes
E) prairie dogs were part of a negative feedback loop once they were removed
When the rains came down on the rocky mountainsides, the water ran down into the grasslands where the
prairie dogs were active and ________.
C) quickly soaked into the loose soil, watering the grasses
The ranchers now wanted to bring back the prairie dogs because they realized that ________.
A) the prairie dogs kept the soil loose, so rain sank in and grasses grew
In a previous chapter you read about "keystone species." How do the prairie dogs in this story meet the
definition of a keystone species?
Their burrows loosened the soil and served as homes for other species; they helped with nutrient
recycling. They helped water sink into the soil and kept soil loose for grassroots. When they were
removed, the system collapsed.
a system receiving inputs and producing outputs without undergoing any changes in size or function is said to be in
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
A natural ecosystem, undamaged by human activity, is
a closed system of organic and inorganic materials as well as energy; where everything is recycled.
A small section 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
the biosphere consists of the
sum of all the planets living organisms and the abiotic portions of the environment
are required in large amounts for organism to survive
the largest pools of carbon in the carbon cycle are
sedimentary rocks and fossil fuels
The origins in all phosphorus in biological tissue is
or phosphorus dissolved int he ocean and taken up by shellfis
the origin in all nitrogen in biological tissue is
humans have dramatically altered the rate of nitrogen fixation into forms usable by autotrophs
as we produce synthetics fertilizers and apply them to crops, lawns and parks
underground water reservoirs
rocks that have undergone heat or pressure that causes it to change form is called
individuals of a single species fighting over access to a limiting resource is one example of
By definition, parasites-----their hosts
feed on and harm
------ capture solar energy and use photosynthesis to produce sugars
grazing animals such as deers
zoooplankton-eating fish are
herbivory is a type of
Benthic organism in the great lakes
are helped by the presence of zebra mussels
microbes in our digestive tract represent a type of-----relationship
which of the following are pioneer species
Efforts at urban restoration
Efforts at urban restoration intend to undo damage done to communities due to urban development.
Environmentally and economically acceptable means of controlling introduced invasive species
public education, introduction of appropriate predators , examination of imported goods.
desert and tundra have both
have relatively low precipitation
taiga and tundra both
have low temperature throughout the year