Download Chapter 3 Notes

Agriculture Technology Class
Chapter 3 Notes
Biomes of North America
Ecosystems consist of:
a.
b.
c.
d.
plants
animals
microorganisms
nonliving materials
that all interact with each other.
Boundaries between ecosystems frequently overlap.
Biomes are grouping of ecosystems within a region that
have similar vegetation and climatic conditions.
Climate is determined by altitude and distance from the
equator.
Plankton are the main food source either directly or
indirectly for nearly all marine animals.
Phytoplankton –microscopic plants found in water.
Zooplankton –microscopic animals found in water.
Water environments:
Consist of Temperature, light, current, minerals,
oxygen.
The most limiting factor in the water environment
determines how acceptable the environment will be.
Turbid –refers to how cloudy water is due to suspended
particles. Deals with ‘light penetration’ which can limit
photosynthesis.
Dissolved minerals can affect aquatic environments.
Nitrates and phosphates can stimulate growth of blue
green algae that blocks light penetration.
Dissolved water concentration is affected by the flow and
temperature of water.
Lotic habitats deals with water flowing freely in streams
and rivers. Supports little plant life.
Lentic habitats deals with standing water. Water
temperatures can vary due to depths. Shallow water is
warm. Deep waters are cold on bottom and warm on top.
(Thermal stratification.)
Dissolved oxygen levels. Warm temperatures with slow
currents will yield low levels of oxygen. Cold
temperatures with fast currents will have high oxygen
levels.
Wetlands are areas of land that are flooded and may
consist of dry land parts of the year. Land is usually
porous and soaks up large amount of water.
Marine biomes:
 Largest biome.




Oceans, bays, estuaries
71% of earth
Salinity –salt concentrations
Most marine life is found in shallow waters due to
high amounts of light and low amounts of water
pressure.
 As waters become deeper, pressure rises and light
sources decrease. (lesser amounts of food)
Ocean environmental zones:
 Intertidal zone – near shore. Exposed during low
tide
 Neritic zone –part of the continental shelf. Most
favorable living area of marine life.
 Oceanic zone –starts at outer edge of continental
shelf. Deep ocean waters and limited life species.
200 yards.
Estuary – area of mixing of salt and freshwaters.
Terrestrial biomes:
Large ecosystems consisting of plants, animals
and other living organisms that live on land.




Desert biome
Tundra biome
Grassland biome
Temperate forest biome
 deciduous forests –leaf bearing trees
 strata—layers of vegetation
 canopy – ceilings of leaves
 understory –short trees
 shrub layer – short brushes beneath the
understory
 herb layer – shortest plants next to ground
 forest floor – decaying plant matter
 Coniferous forest biome
 evergreens and/or conebearing trees
(conifers)
 very little other growth