Soil Horizons and Environmental Science

These flashcards cover key terms and concepts related to soil horizons, ecological processes, environmental science, and human impact on ecosystems.

Soil Horizons

The layers of soil that are characterized by their composition and depth, including O, A, E, B, C, and D layers.

Organic Horizon

The top layer of soil that contains decomposed organic matter, commonly known as humus.

A Horizon

The layer of top soil that contains less humus compared to the O horizon and is rich in minerals.

E Horizon

The layer of soil that may not always be present and is characterized by leaching of metals.

B Horizon

Also known as subsoil, this layer accumulates minerals leached down from the upper layers.

C Horizon

The layer made up of larger pieces of bedrock, with little soil development.

Nitrogen Cycle

The process by which nitrogen is converted in the environment and within organisms, consisting of processes like denitrification, nitrogen fixation, and nitrification.

Denitrification

The process by which nitrates are reduced and ultimately converted into nitrogen gas (N2) which is released into the atmosphere.

Nitrification

The process of converting ammonia (NH4+) into nitrates (NO3-) through microbial activity.

Bioaccumulation

The accumulation of substances, such as pesticides or other chemicals, in an organism over time.

Carbon Cycle

The movement of carbon through the environment, involving processes such as photosynthesis, respiration, and decomposition.

Tragedy of the Commons

A situation where individuals act in their own self-interest and deplete shared resources, leading to overall detriment.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance; its removal can cause ecosystem collapse.

Primary Productivity

The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.

Eutrophication

The process of nutrient pollution that leads to increased plant growth and decay, resulting in lower oxygen levels.

Ecological Succession

The process of change in the species structure of an ecological community over time, including primary and secondary succession.

R-selected Species

Species that reproduce quickly, have many offspring, and provide little to no parental care.

K-selected Species

Species that produce fewer offspring, provide significant parental care, and have longer life spans.

Invasive Species

Non-native species that spread widely in a new ecosystem, often causing harm to native species.

Endangered Species Act

A law designed to protect critically endangered species from extinction as a consequence of economic growth and development.

CITES

The Convention on International Trade in Endangered Species of Wild Fauna and Flora, to ensure that international trade does not threaten the survival of species.