A classification of plant formations and associated animal life into biotic units based on the predominant plant types, with at least eight major terrestrial types, is referred to as a(n) ___.
Which of the following allocates the greatest amount of biomass to photosynthetic tissue and the least amount to supportive tissue?
the extirpation of many of the island's bird and reptile species
The introduction of the brown tree snake in the 1940's to the island of Guam has resulted in
This is caused by excessive nutrient runoff into aquatic ecosystems
biodiversity hot spots
key geographic areas with high concentrations of endemic species and a large number of endangered and threatened species are known as __.
fragmented forests support a lesser biodiversity because the forested-adapted species leave, and only the edge and open-field species can occupy fragmented forests
which of the following is true about the current research regarding forest fragmentation?
Using the formula for effective population size, imagine a population of 1,000 small rodents. Of these, 300 are breeding females, 300 are breeding males, and 400 are nonbreeding juveniles. What is the effective population size?
Most of the nutrients in the ecosystem are removed in the harvested timber
Why do logged tropical rain forest soils typically have nutrient-poor soils?
C3 plants are more limited by CO2 availability because they lack mechanisms to prevent transpirational water loss
When levels of CO2 are experimentally increased in a typical grassland community, C3 plants generally respond with a greater increase in productivity than C4 plants. This is because
tropical rain forests
The highest diversity of plant and animal life occurs in
Which of the following is an example of a nonrenewable resource?
rate at which a renewable resource can be used indefinitely without reducing its available supply.
A sustained yield refers to the
In forestry, the period of time between harvests of trees at a site is called the ____.
needle-leaf evergreen leaves
Which of the following is the predominant leaf form of trees where the growing season is very short or where nutrient availability severely constrains photosynthesis and plant growth?
warm areas with seasonal rainfall in the tropics
savannas typically occur in
The dominant biome in mediterranean climates with hot, dry summers and cool, moist winters is
marine life that is caught, but is unwanted and discarded, is referred to as __
that current global warming is likely anthropogenic
The video on climate change and your textbook both agree on all the points below except
increase in developed countries and decrease in developing countries
as a consequence of global climate change, crop production is likely to
As aerosol concentrations increase
temperatures, sea levels, variability of climate, and precipitation will all increase
The general circulation models developed by atmospheric scientists predict that in the future,
increase their rate of photosynthesis
in response to an increase in atmospheric carbon dioxide, plants generally
deforestation is a major cause of increased atmospheric concentrations of
which of the following gases in the atmosphere is not considered a greenhouse gas
suppressing lightning-strike fires
which of the following would not be considered a goal of restoration ecology?
linking reserves by habitat corridors
The dispersal of plants and animals from one reserve to another within a network of reserves is best accomplished by
a large reserve exposes organisms to proportionately more habitat edges
which of the following is NOT an advantage for preserving a large reserve rather than a small reserve?
The area of suitable habitat necessary for maintaining the number of individuals and ensuring the long-term survival of a species should be highest for a ___.
occurs in a single geographic area and nowhere else
An endemic species is best defined as a species that
the primary cause of modern extinctions is ____
The negative consequences of harvesting a natural resource, such as the soil erosion and sedimentation of a river that occur after a forest is logged, typically are not included in the market price of the resource; these costs are referred to as
the rate of soil erosion increases
When trees are harvested and removed ____.
The vegetation formation dominated by needle-leaf evergreen trees and occurring at high latitudes or high elevations where growth is restricted to a few months of the year due to low temperatures is referred to as ___
frozen, treeless plains dominated by sedges, heaths, and willows at high latitudes and elevations is ____
some trees are cut but others are left to provide seed for new trees
Which of the following is not a characteristic of swidden agriculture or shifting cultivation?
Cultural eutrophication refers to the
accelerated nutrient enrichment of bodies of water due to runoff of chemical fertilizers.