The study of relationships between organisms and the environment.
The process by which populations change over time.
The largest spacial scale and highest level of ecological organization — i.e. the Earth.
Robert MacArthur
Studied warbler species in North America to see how they coexisted in their environment. The warblers were gathering insects from different parts of the trees.
Stable Isotope Analysis
Analysis of the relative concentrations of stable isotopes, such as C13 and C12, in materials. This is used to study the flow of energy and materials through ecosystems.
All organisms that live in an area and the physical environment in which those organisms interact.
The raw materials an organism must require from the environment to live.
Plants such as orchids and ferns that live on the branches and trunks of other plants. As they grow the form a “mat” as they trap organic matter, and these mats are rich in nutrients.
Evolutionary process by which organisms increase their ability to live in a new climate regime.
Major divisions of the terrestrial environment. Biomes are distinguished by their dominant plants.
What causes the variation in climates?
The uneven way in which the Earth is heated by the sun. This is due to the angle and which the Earth sits in relation to the sun.
What causes wind?
Differences in temperature and moisture level in the air.
Coriolis effect
Caused by the rotation of the earth which produced a deflection of winds and water currents to the right of their direction of travel in the N. Hemisphere and to the left in the S. Hemisphere. This is why winds do not move directly north to south.
O Horizon
organic horizon. The top layer of soil, made up of fallen organic matter. The deeper areas of the O horizon include partially decomposed matter.
A horizon
This horizon contains a mixture of mineral materials such as clay, silt, and sand. The A horizon is generally rich in mineral nutrients.
B horizon
Clays, humus, and other materials that have been transported by leaching from the A horizon. This horizon has the roots of many plants.
C horizon
The deepest layer of soil. It contains weathered parent material and rocks. Under the C horizon is unweathered parent material, such as bedrock.
Partnerships between fungi and root systems in which nutrients are gathered.
Tropical rain forest characteristics
By the equator, warm and wet all year, organisms have evolved to use the vertical dimension of the forest.
Tropical dry forest characteristics
Are found north and south of tropical rainforests, are more seasonal and have a dry season, old soils that are less acidic, and life depends on water.
Tropical savanna characteristics
North and south of tropical dry forests and within 10-20 degrees of the equator. Has wet and dry seasons, and drought combines with fire to maintain the savanna. Has impermeable soils that keep moisture toward the top of the soil layers.
Desert characteristics
Occur where subtropical air descends and drys the landscape. Little precipitation. Soil low in organic matter and can sometimes be classified as “lithosols” meaning stone or mineral soils.
Calcium carbonate rich soil horizon found in aged desert soils.