Fundamentals of Ecology: Organisms, Environment, and Soil

Fundamentals of Living Things and Environment

Composition of Living Matter

Living things are primarily composed of carbon, oxygen, hydrogen, and nitrogen. These elements constitute organic matter.

Essential Life Functions

Living things perform three main functions:

• Nutrition
• Interaction
• Reproduction

Conditions Necessary for Life

The fundamental conditions required for life include:

1. Liquid water
2. A magnetic field
3. A protective atmosphere
4. Carbon compounds
5. An energy source

Environmental Factors

Abiotic Factors

These are the environmental and physical conditions that influence where organisms can live.

Biotic Factors

These encompass the living things within an environment and the interactions between them.

Ecosystem Components

Biotope

This is the non-living part of an environment, including all the abiotic factors.

Biocenosis

This refers to all living things from every species that inhabit a defined area (the biotope), possessing everything necessary for survival.

Ecosystem Definition

An Ecosystem is a natural environment (biotope) inhabited by a group of living things (biocenosis) that interact with each other and their surroundings.

Formula: Biotope + Biocenosis = Ecosystem

Roles within the Ecosystem

The roles of living things include:

• Producers
• Consumers (primary, secondary, tertiary)
• Decomposers

Food Chains

Matter and energy are transferred between different living things in an ecosystem. For example: Acorns → Squirrel → Eagle.

Soil Structure and Function

Components of Soil

Soil contains mineral particles, air, and water (absorbed by plant roots), as well as dead organic matter and various types of living things.

Soil Formation Process

Soil forms as a result of rocks being weathered, or broken up, by water, ice, and living things.

Life in the Soil

Organisms in the soil play an essential role in the cycle of matter by breaking down dead animals and plants into vital nutrients, besides plant roots.

• Detritivores: Earthworms, insects, mites…
• Decomposers: Bacteria and fungi…

Functions of Soil

The soil performs key functions:

1. It stores the rainwater needed by plants.
2. Decomposers feed on the remains of living things, releasing simple inorganic molecules such as nitrogen and mineral salts.

Soil Horizons

• Topsoil: Made up of partially decomposed organic matter and the majority of living things found in soil.
• Subsoil: Formed by mineral particles of different sizes and nutrients resulting from the decomposed organic remains from the topsoil.
• Parent Material: No alteration occurs; no soil formation processes are active here.

Biomes and Biodiversity

Biome Definition

Areas with similar climatic conditions where communities of living things share common features.

Photosynthesis Requirements

Abiotic factors needed for photosynthesis are: Temperature, rainfall, and quantity of light.

Biodiversity

This is the variety of different types of life that can be found in a specific biome.