APES unit 2
species diversity
# of species in a region or in a particular type of habitat
A one-hectare pond is sampled in early September. The sample yields 1 small catfish as well as 17 benthic invertebrates that represent 10 species. Which of the following can be estimated from the sample for the invertebrates in the pond? A: The species richness B: The pond's productivity C: The uniformity of species distribution in the pond D: The degree of disturbance E: The stability of the ecosystem
A
Which of the following would be categorized as a cultural ecosystem service of forests? A: Recreation and scenic areas for tourism B: Timber and landscape materials C: Mushroom and plant harvests D: Soil stabilization and air purification
A explanation: recreation and tourism are the nonmaterial or cultural ecosystem services of forests
Based on the theory of island biogeography, which of the following is the most likely reason that an island in the ocean that is 5 kilometers from a continent would have a higher number of species than one that is 15 kilometers from a continent? A: There are more species that have the ability to travel 5 kilometers than can travel 15 kilometers. B: Islands that are closer to continents always have a wider range of habitats than more distant islands do. C: There are smaller populations of each species on islands that are at greater distances from continents. D: Islands that are closer to continents always have more ecological niches than more distant islands do.
A explanation: takes less energy and less locomotion to travel 5km than 15km
specialist
A consumer that primarily eats one specific organism or feeds on a very small number of organisms.
Highly specialized species tend to evolve on islands because of the environmental conditions and resource availability. Based on the theory of island biogeography, which of the following would most likely experience the greatest decline of specialist species if an invasive species emigrated from the mainland? A: A small island a far distance from the mainland B: A small island in close proximity to the mainland C: A large island a far distance from the mainland D: A large island in close proximity to the mainland
B
The consumption of mosquitoes by bats and the control of flooding provided by tropical forests in mountainous areas of Central America are examples of A: adaptive radiation B: ecosystem services C: evolution by natural selection D: ecological equilibrium E: positive feedback loops
B
Which of the following is a measure of the biodiversity of an ecosystem? A: The total number of individuals of a single animal species B: The density of individuals in a hectare C: The total number of different plant species D: The soil depth at which burrowing insects are located
C explanation: the number of different species is a primary measure of biodiversity that is also known as species richness
For which of the following reasons do small isolated islands have a greater rate of species extinction than larger, less isolated islands? A: Small isolated islands are more likely to receive more migrating species. B: Small isolated islands provide opportunities for a greater diversity of species. C: Because of their size, small isolated islands accumulate more species by chance. D: Small isolated islands have a lower availability of resources. E: Because they have fewer available niches, small isolated islands are targeted and colonized by species.
D
Which of the following best describes a supporting ecological service provided by wetlands? A: Wetlands serve as a source of aesthetic inspiration for art and literature. B: Wetlands provide opportunities for ecotourism, which provides revenue to the local economy. C: Wetlands serve as a major reservoir for nitrogen in the nitrogen cycle. D: Wetlands provide a habitat for a wide variety of organisms.
D
Which of the following statements about levels of biodiversity is correct? A: genetic biodiversity is a measure of the total number of genes in a community B: a narrow distribution of habitats leads to an increase in species diversity C: global hotspots are areas where species diversity is thriving due to habitat restoration D: a population with high genetic biodiversity is better able to respond to environmental stressors
D explanation: genetic diversity is an important part of natural selection, as genetic variation is more likely to allow some individuals in a population to survive in a changing environment
Which of the following can be used to assess the biological diversity of an area? A: Population size of each species and area occupied by each population B: Minimum population area and minimum viable population size C: Ratio of r-strategists to K-strategists and life expectancy of K-strategists D: Number of individuals under fifteen years old and number of individuals over sixty-five years old E: Genetic variation within each species and number of species present
E
ecosystem engineers
a keystone species that creates or maintains habitat for other species
genetic diversity
a measure of the genetic variation among individuals in a population
random process
a repeatable process with unknown individual outcomes but a long-run pattern
generalists
a species with a broad niche that can tolerate a wide range of conditions and can use a variety of resources
how do organisms adapt to their environment over time?
both in short and long-term scales, through incremental/small changes at the genetic level
does wildlife engage in short or long-term migration?
both, for a variety of reasons, including natural disruptions
cause of sea levels varying significantly
changes in the amount of glacial ice on Earth over geologic time
pioneer members/species
commonly move into unoccupied habitat and over time adapt to its particular conditions, that may result in the origin of new species
predator-mediated competition
competition in which a predator is instrumental in reducing the abundance of a superior competitor, allowing inferior competitors to persist
result of environmental changes (sudden and/or gradual)
could threaten a species' survival, requiring individuals to alter behaviors, move or perish
anthropogenic activities and effects
derived from human activities opposed to those occurring naturally can disrupt ecosystem services, which could result in economic and ecological consequences
levels of biodiversity
genetic div, species div, and ecosystem div
what does biodiversity in an ecosystem include?
genetic, species and habitat diversity
provisioning services
goods that humans can use directly ex: food crops, furs, natural rubber, lumber
intrinsic value
has worth independent of any benefit it may provide to humans
How have islands been colonized?
in the past, by new species arriving from elsewhere
what does ecological tolerance apply to?
individuals and species
result of major environmental change or upheaval
large swathes of habitat changes
consequence of loss of habitat
leads to a loss of specialist species, followed by a loss of generalist species also leads to reduced numbers of species that have large territorial requirements
why have species evolved into specialists vs. generalists?
limited resources, such as food and territory on most islands long-term survival of specialists may be jeopardized if and when invasive species are introduced and outcompete the specialists
ecosystem diversity
measure of the diversity of ecosystems or habitats that exist in a given region
how does having a larger number of species benefit ecosystems?
more likely to recover from disruptions
regulating services
natural ecosystems help to regulate environmental conditions ex: pollination, decomposition, water purification, erosion and flood control
supporting services
natural ecosystems provide support services that are extremely costly ex: nutrient cycling, water cycling and soil formation and retention
species richness
number of different species found in an ecosystem
periodic process
occurring at repeated intervals
episodic process
occurring occasionally and at irregular intervals
Earth system processes
operate on a range of scales in terms of time
what are the three different types of Earth system processes
periodic, episodic, random
indicator species
plant or animal that by its presence, scarcity or chemical composition, demonstrates that some distinctive aspect of the character or quality of an ecosystem is present
two main types of ecological succession
primary and secondary succession
cultural services
provides an aesthetic benefit for which people will pay ex: tourism, recreation (bike path)
what are the categories of ecosystem services?
provisioning, regulating, cultural, supporting
ecological tolerance
range of conditions, such as temperature, salinity, flow rate, and sunlight that an organism can endure before injury or death results
secondary succession
reestablishment of a damaged ecosystem in an area where the soil was left intact after a disturbance/disaster
what have island species evolved into?
specialists vs. generalists
instrumental value
species may have worth as an instrument or tool that can be used to accomplish a goal also ECOSYSTEM SERVICES
keystone species
species whose activities have a particularly significant role in determining community structure
primary succession
succession that occurs in an area in which no trace of a previous community is present, food web is created
relationship between population and its genetic diversity
the more genetically diverse a population is, the better it can respond to environmental stressors a population bottleneck can lead to a loss of genetic diversity
ecological succession
the predictable replacement of one group of species by another group of species over time
island biogeography
the study of the ecological relationships and distribution of organisms on islands, and of these organisms' community structures
what will succession in a disturbed ecosystem affect?
total biomass, species richness, and net productivity over time
do natural disruptions to ecosystems have environmental consequences?
yes, and it may be great as or greater than many human-made disruptions