 Its members compete with one another for food, water, mates, and other resources.  Some species have adaptations that reduce competition within a population.

 Is made up of several populations interacting with one another

 A change in one population in a community will cause changes in the other populations.

 Is the role a species plays in a community  Includes the space, food, and other conditions an organism needs to survive and reproduce.  It includes how a species uses and affects its environment.

In California, rainbow trout live primarily in riffles (shallow, fast-flowing areas) and feed on pikeminnows; in the absence of the minnows, the trout’s area expands to include the pools and more terrestrial insects that fall on the pool surface. The desert bighorn prefers desert mountain ranges — these mountain ranges constitute the bighorn’s habitat.

 Terrestrial ecosystem – those located on land. –Two major adaptations that allowed plants to live on land were:  1. Vascular Tissue that allows plants to survive on land by letting them absorb water, & nutrients through their roots and transport food produced in the leaves to the rest of the plant.  2. The presence of mechanical strengthening tissue in stems and leaves. –Three important adaptations that allowed animals to live on land were:  1. Eggs that can develop out water.  2. Internal fertilization.  3. Ability to get oxygen from air rather than water (lungs).

 Aquatic ecosystem may beeither or saltwater Major Adaptations of aquatic organisms: Plants 1) Flexibility in the event of changes in water level or water movements 2) Air-filled cavities often extend throughout the leaves & stems of aquatic plants, providing an internal atmosphere Animals 1) Gills to obtain oxygen from the water. 2) Fins, scales and shells for movement and protection. 3) Osmoregulation: Ability to live in water with different salt contents (ie: freshwater or saltwater)

The aquatic biome consisting of waters containing 3.5% salt on average; includes the oceans and covers more than 70% of the Earth's surface. One major adaptation required to live in a marine biome is osmoregulation. Osmoregulation is the regulation of the movement of water by osmosis into and out of cells; the maintenance of water balance within the body.

 Include – streams, ponds, and lakes  Major adaptations include: –Osmoregulation (reverse of marine biomes) –Their gills must be able to diffuse dissolved gasses while keeping the salts in the body fluids inside. gills –Their scales reduce water diffusion through the skin: freshwater fish that have lost too many scales will die. –Well developed kidneys to reclaim salts from body fluids before excretion. kidneys

 Is a coastal body of water, partially surrounded by land, in which fresh water and salt water mix.  Salinity ranges between that of seawater and that of freshwater, and depends on how much fresh water the river brings into the estuary.

 Climate –Temperatures never rise above freezing for long.  Short periods of winter sunlight & long summer days.  Permafrost – layer of permanently frozen ground. Adaptaions include: Plants: -shallow roots. -able to withstand long periods of limited sunlight. Animals: -thick layer of fat. -thick fur. -white color for camouflage.

 Climate – severe winters and short, mild summers (warmer and wetter than tundra)  Vegetation: Land of mixed pine, fir, hemlock, and spruce trees  Animals – migratory birds, moose, lynx, porcupines

 An arid region with sparse to almost not existent plant life  Vegetation –succulents; fast-growing herbs.  Animals – must be able to withstand limited water, very hot days and often very cold nights.

 Receive between 25 and 75 cm of precipitation annually  Vegetation – grasses  Animals – buffalo, cattle, prairie dogs, foxes, ferrets, snakes, lizards, birds, insects

 Precipitation – 70 – 150 cm annually; warm summers.  Vegetation – broad- leaved hardwood trees that lose their foliage annually (oak, maple, and beech)  Animals – squirrels, mice, rabbits, deer, many birds, and bears

 Is uniformly warm and wet (gets 400 cm of rain annually).  Vegetation – jungles of dense, tangled broad- leaved evergreens.  Animals – parrots, monkeys, snakes, lizards, big cats.

INCLUDES:  All the Biomes on the planet.  Biotic factors: all the living organisms that inhabit an environment.  Abiotic factors: all the nonliving parts of the environment: –Air currents –Temperature –Moisture –Light –soil

The Biosphere is made up of all the biomes on the planet, and includes both biotic and abiotic factors.