a group of various species that live in the same place & interact with one another.
what is an ecosystem?
a community along with the living and non living enviroment.
what is a community of organisms?
a web of relationships
what are examples of biotic factors that affect an ecosystem.
relationships between organisms
what does biotic describe?
living factors that in an ecosystem. they also include once-living things such as dead organisms & the waste of an organism
what are abiotic factors
the physical or nonliving factors of an enviroment examples are oxygen, water, rocks, sand, sunlight, temperature & climate.
what is a habitat?
the place where an organism lives.
what is biodiversity
the variety of organisms in a given area
what can have a big influence on biodiversity?
-high or low temperatures
> these lower biodiversity
-limited food or water
ecosystems with high biodiversity
are more often able to resist damage
what is succession
the replacement of one kind of community by another at a single place over a period of time
what are pioneer species?
the first organisms to appear in a newly made habitat are often called pioneer species. They change the habitat in such a way that other species replace pioneer species. often new species replace pioneer species.
how does an ecosystem respond to change?
in such a way that the ecosystem is restored to equilibrium.
what partly determines the species that live in a particular place?
what is climate?
the average weather conditions in an area over a long period of time
what is a biome?
a large region characterized by a specific kind of climate & certain kinds of plant and animal communites
what are 2 key factors of climate that determine biomes
temperature and precipitation
precipitation also determines the kinds of species that are found in a biome
how are earth's major terrestrial biomes grouped?
by latitude into tropical, temperate, & high- latitude biomes
latitudes Temperate 30 to 60 degrees tropical near equator 60 degrees or higher high latitude
how does latitude affect a biome
it affects the amount of solar energy that a biome receives & thus affects the biomes temperate range.
receive large amounts of rain & are warm all year.
they have the greatest biodiversity of any land biome. at least half of earth's species of land organisms live in tropical land forests.
tropical grasslands. get less rain then rain forest. long dry season and short wet seasons. the most well known are in eastern africa
get very little rain. they have less water & have few plants and animals.
- have a wide range of temperatures throughout the year
- temperate grasslands
have moderate precipitation & cooler temps. than savannas. often highly productive when used for agriculture.
grow in mild climates that receive plenty of rain. Deciduous shed leaves in fall because of cold winter. Evergreen do not.
receive little precipitation. they have a wide temperature range throughout the year.
high latitude biomes
have cold temperatures. coniferous forest in cold wet climates > taiga
winters are long and cold. most precipitation falls in summer
tundra gets very little rain so plants are short most water is frozen.
not usually called biomes most often referred to as aquatic ecosystems.
- organized in fresh water ecosystems, wetlands, estuaries, & marine ecosystems
fresh water ecosystems
located in bodies of fresh water such as lakes, ponds, & rivers. variety of plants, fish, arthrpods, mollusks, & other inverebrates
provide a link between the land & fully aquatic habitats. water loving plants dominate. many species of birds, fishes, & plants are supported. Important because they moderate flooding and clean water that flows through them..
is an area where fresh water from a river mixes w/ salt water from an ocean. productive because they constantly receive fresh nutrients from rivers & the oceans
are found in the salty water of the oceans.
What is the primary source of energy for an ecosystem?
What doe photosynthetic organisms do?
change light energy from the sun into energy that they can use to grow. examples plants & algae
What are producers?
the basic food source for an ecosystem.
What are consumers?
organisms that eat other organisms instead of producing their own food.
what are decomposers?
are organisms that break down the remains of animals. ex. algae and fungi
how does energy flow in an ecosystem?
from the sun to the producers to consumers to decomposers.
what is a trophic level?
Each step in the transfer of energy through an ecosystem.
what forms a food chain?
In ecosystems energy flowing from one trophic level to the next.
what is the first trophic level made up of?
What uses the energy in sunlight to build energy rich carbs.
plants, algae, & some bacteria.
what is the 2nd trophic level made up of?
herbivores which eat producers.
what is the 3rd trophic level include?
some carnivores are on the 3rd trophic level because they eat herbivores..
what is a carnivore?
any animal that eats another animal
whats on the 4th trophic level?
other carnivores that eat carnivores.
what are omnivores?
animals that are both herbivores and carnivores, such as bears
what is a food web?
a complicated interconnected group of food chains.
Is energy stored at each link in a food web?
yes, but some energy that is used dissipates as heat into the enviroment & is not recycled.
the 10 % rule
trophic levels starts with Producers with the most energy then herbivores, small carnivores, and then large carnivores.
what level has the most energy in the pyramid?
the lowest, producers.
what is an energy pyramid?
a triangular diagram that shows an ecosystem's loss of energy which results as energy passes through the ecosystem's food chain is called an energy pyramid.
what are five of the most important substances for life?
water, carbon, oxygen, nitrogen, & phosphorus. an ecosystem must be able to cycle these kinds of matter in order to support life.
what is the water cycle?
continuously moves water between the atmosphere the land and the oceans
what is the water cycle?
- water vapor condenses & falls to earths surface as precipitation
- some of this water percolates in to the soil & becomes groundwater. others runs across the surface or earth into rivers, lakes, & oceans.
- then, the water is heated by the sun & re-enters the atmosphere by evaporation. Water also evaporates from trees.
what is transpiration?
process of water evaporating from trees and plants.
both of these cycles are closely tied together
carbon & oxygen cycles.
what is the carbon cycle?
the continuous movement of carbon from the nonliving environment into living things & back.
what play an important role in cycling cartoon & oxygen through an ecosystem.
animals, plants & other photosynthesizing organisms
-plants use the CO2 in the air to build organic molecules during photosynthesis.
- during photosynthesis oxygen is released into the surroundings. Many organisms such as animals use this oxygen to help break down organic molecules which releases energy & CO2 then plants can use the CO2 in photosynthesis. Carbon is also released in the air through combustion.
What is combustion?
The burning of a substance. The burning of fossil fuels releases CO2 in the atmosphere. burning things like oil & coal.
why must nitrogen be cycled?
must be cycled through an ecosystem so that the nitrogen is available for organisms to make proteins
what is the nitrogen cycle?
the process in which nitrogen circulates among the air, soil, water, & organisms in an ecosystem.
nitrogen cycle steps
most organisms cannot use nitrogen gas. It must be changed into a different form.
A few bacteria have enzymes that enzymes that can break down N2. These bacteria supply the nitrogen that all other organisms need.
the bacteria splits N2 & then binds nitrogen atoms to hydrogen to form ammonia NH2. Nitrogen may be fixed by lightening. but more is fixed by bacteria. Nitrogen fixing bacteria lives in the soil & on the rots of some plants. it is also fixed when humans burn fuels in vehicles & industrial plants.
what is nitrogen fixation?
the process of combing nitrogen w/ hydrogen to form ammonia
how do plants gets nitrogen?
assimilation. its the process in which plants absorb nitrogen.
what is ammonification?
nitrogen from animal waste or decaying bodies is returned to the soil by bacteria. Ammonia is then converted to nitrite & then nitrate by the process of nitrification. In denitrification nitrate is changed to nitrogen gas which returns to the atmosphere.
what is an important part of ATP & DNA
phosphorus & it must be cycled in order for an ecosystem to support life.
what is the phosphorus cycle?
the movement of phosphorus in different chemical forms from the surroundings to organisms & then back to the surroundings. it is often found in soil & rocks as calcium phosphate, which dissolves in water to form phosphate. the roots of plants absorb phosphate, humans & animals that eat the plants reuse the organize phosphorus. When they die phosphorus is returned to the soil.