Ecological Factors and Organism Adaptations

Ecological Factors and Environmental Impact

Ecological factors are characteristics of the environment that affect living things. There are two main types:

• Biotic factors: The organisms that share the same natural environment.
• Abiotic factors: Physical and chemical conditions such as sunlight, temperature, oxygen content, water, and the concentration of salts and minerals.

The Role of Limiting Factors

Each species has specific requirements to develop normally. A limiting factor is a factor that is above or below the point at which an organism cannot develop properly. For example, in arid zones, water is a limiting factor for plants.

Adaptation of Organisms to the Environment

Organisms must adapt to the ecological factors of their environment in order to survive. Adaptation is the evolution of organisms so that they are able to survive in a specific environment. It can be morphological, physiological, or behavioral adaptation.

Generalist vs. Specialist Organisms

Generalist organisms are able to survive in a greater variety of environmental conditions. They are normally animals with a varied diet. Omnivores are usually generalists, like raccoons. Specialist organisms cannot tolerate significant changes to their environment. Herbivores are often specialists. For example, the koala almost exclusively feeds on eucalyptus leaves.

Adaptation to Water Scarcity

Water is scarce in arid zones (little rainfall and moisture in the ground) and in cold areas where most of it is frozen, meaning organisms cannot use it. Adaptations to obtain water and reduce its loss include:

• Storage in special tissues
• Drought-resistant seeds
• Leaves with a small number of stomata that open at night
• Deep and extensive root systems
• Hard, small leaves
• Annual plants completing their life cycle in the season that favors their development

Adaptation to Temperature

Physiological functions depend on the external temperature. Within the right temperature range, biological processes are optimized. Above or below this range, these processes cannot be carried out properly. In extreme temperatures, biological functions can stop working. Adaptations to temperature include:

• Reducing blood flow to avoid heat loss
• Skin insulation (fat and hair)
• Metabolic rate slowdown in winter (hibernation)
• Individuals coming together to increase the temperature around them
• Searching for warmer zones
• Plants growing close to the ground to reduce heat loss
• Important organs growing underground
• Leaves falling in autumn