Introduction to Ecosystems and Ecology

Ecosystem

An ecosystem is a community of plants and animals (living things) that interact with each other and their natural surroundings, including non-living things such as rocks, water, and air. Each ecosystem is sustained by a flow of energy through it and the recycling of nutrients within it.

Community

When plants and animals live together, they form a community.

Photosynthesis

Photosynthesis is the process in which plants absorb CO₂ from the air and convert it into sugar using the sun's energy.

Biomes

Biomes are large ecosystems at the global scale where the climate and vegetation are uniform.

Xerophytic Plants

Xerophytes are plants that have adapted by altering their physical structure to survive in harsh climates. These plants exhibit several adaptations that allow them to thrive in arid environments. For example, xerophytic plants, such as cacti:

• Do not have leaves but instead depend on chlorophyll in the outer tissue of their skin to conduct photosynthesis.
• Reduce transpiration by eliminating leaves or greatly reducing leaf size.
• Have a waxy surface on their skin that seals in moisture and produces food for the plant.

Food Chain

A food chain represents the transfer of energy through an ecosystem from primary producers (plants) to consumers (animals) and decomposers (bacteria and fungi).

Afforestation

Afforestation is the establishment of a forest or stand of trees in an area where there was no forest before.

Reforestation

Reforestation is the establishment of forest cover, either naturally or artificially, in an area that was previously forested.

Podzol Soil

Podzol soil is a type of soil where vast coniferous forests grow. It has the following characteristics:

• The ground surface is covered with a thick layer of needles.
• Beneath the needles is a pale gray sandy layer because rain leaches away nutrients.
• The soil is acidic.
• Few worms and microorganisms can live in it.

Nutrient Recycling

Nutrient recycling is the process in which minerals necessary for plant growth are taken up from the soil and returned when plants shed their leaves or die.

Energy Flows

Energy flows describe the transfer of energy through an ecosystem by means of a food chain. The primary source of energy is sunlight.

Biomass

Biomass refers to the total amount of organic matter contained by plants and animals in a given area.

Non-Living Things

Non-living things encompass anything that was never alive.

Living Things

Living things are characterized by their ability to grow, reproduce, and respond to their environment.

Logging

Logging refers to the industry of timber harvesting.

Litter

Litter consists of the remains of dead animals and plants.

Sustainable Forestry

Sustainable forestry is a way of using forest resources without depleting them or harming the environment.