Chapter 31: Communities and Ecosystems

________ is the process of converting ammonium to nitrate, which is done by nitrifying soil bacteria.

________ is the process of converting nitrate to nitrogen gas, which is done by denitrifying bacteria.

________ and some beetles, termites, and maggots are soil detritus feeders.

________ are also called biomes and are defined by temperature and rainfall.

________ are photosynthetic organisms that produce most of the organic nutrients for the biosphere.

________ occurs when environmental change is too rapid for suitable adaptations to evolve.

________ convert organic nutrients back into inorganic chemicals and release them to the soil or atmosphere, completing the chemical cycle in an ecosystem.

________ ecosystems cover 70 % of the Earth's surface, and the richest ones are near the coasts.

Lemming ________ is affected by the availability of phosphates and calcium in the tundra.

________ are located offshore, and estuaries occur where rivers meet the sea.

________ also interact with the physical environment to acquire food.

________ are animals that eat both plants and animals.

________ and grizzly bears are critical seed dispersers for whitebark pine trees.

________ have significantly decreased the populations of many native species of fish in the Mississippi River system.

________ preformed organic nutrients and release CO2 into the atmosphere.

________ have biotic and abiotic components that regulate population size.

________ are a keystone species in the northwestern United States and Canada.

________ between two species for limited resources has a negative effect on the abundance of both species.

________ is a relationship in which one species benefits while the second species is neither harmed nor benefited.

________ were formed during the Carboniferous period when an exceptionally large amount of organic matter was buried before decomposing.

________ interact with the physical environment to acquire food.

________ feed on detritus floating in marine waters.

________ is a symbiotic relationship where both members benefit.

________ to reduce carbon dioxide emissions include alternative sources of energy and increased energy efficiency of cars and appliances.

________ are the dominant photosynthesizers on land.

________ take detritus from the sea bottom.

________ break down the log and provide food for earthworms and insects living in and on the log.

The ________ provides a home for ants of the species Pseudomyrmex ferruginea.

________ take up carbon dioxide from the air and incorporate it into organic nutrients through photosynthesis.

________ is composed of the remains of dead organisms plus the bacteria and fungi that aid in decay.

The ________ is the final level of biological organization and includes all ecosystems on Earth.

________ graze directly on algae or plants.

The pond or lake must contain vegetation where the backswimmer can hide from ________ and birds.

________ are designated as keystone species in tropical forests.

________ can grow on rocks because the fungal member extracts minerals from the rocks, which are provided to the algal partner.

The ________ is a tropical grassland with a high temperature and alternating wet and dry seasons.

________ is largely dependent on the availability of inorganic nutrients.

________, such as differences in beak sizes of ground finches on the same island, is evidence of competition and resource partitioning.

________ may feed on each other, and birds flying throughout the forest may feed on the ________ and worms living in and on the log.

________ have been found to support communities in some caves and at hydrothermal vents along deep- sea oceanic ridges.

________, zebra mussels, the Chestnut blight fungus, fire ants, and African bees are well- known exotic species that have killed native species.

A group of interacting populations of different species living in the same area.

The number of different species living in a community.

The process of ecological community development on a previously uninhabited area.

The process of ecological community development on an area that has been disturbed but not completely destroyed.

A relationship between two or more organisms that strive for the same resources.

A relationship between two organisms in which one organism, the parasite, benefits at the expense of the other organism, the host.

A relationship between two organisms in which one organism benefits, while the other organism is neither harmed nor benefited.

A relationship between two organisms in which both organisms benefit.

The place where an organism lives and its surroundings.

The role an organism plays in its community, including its interactions with other organisms and its use of resources.

The principle that two species cannot occupy the same ecological niche indefinitely.

The process by which two or more species divide up a resource in a way that minimizes competition.

The process by which two closely related species evolve different traits in order to reduce competition for resources.

Organisms that can produce their own food from inorganic materials.

Organisms that cannot produce their own food and must consume other organisms for energy.

Organisms that eat other animals.

Organisms that break down dead organic matter into simpler substances.

A food web in which energy flows from plants to herbivores to carnivores.

A food web in which energy flows from dead organic matter to decomposers to other organisms.

A linear sequence of organisms in which each organism feeds on the one below it.

A position in a food chain or food web, determined by the organism's feeding relationship.

The processes by which elements and compounds are recycled through the biosphere.