UPSC Essentials: One word a day- Ecological stress

Subject: Environment and Ecology

What is ecological stress?

Ecological or biological stress is defined as a disturbance in ecological balance or ecosystem equilibrium. The disturbance can be physical, chemical, and biological. This stress can be chronic or episodic. It can occur when foreign substances or agents are introduced in large concentrations and can bring ecological change. In living organisms, this can cause survival risk or growth and reproductive restrictions.

(Note: Stress is a physiological condition that results from environmental or social pressure and which may affect the functioning or behavior of its recipients.)

How are environmental stressors categorized?

Stressors can be natural environmental factors. At times they may also result from human activities. Environmental stressors can have a local, regional or global influence.

 Environmental stressors can be categorized into the following categories:

— Physical stress– It refers to brief but intense exposure to kinetic energy. This is a type of ecological disturbance because of its acute, episodic nature.

Examples- volcanic eruptions, windstorms, and explosions.

— Wildfire- A disturbance, during which much of the biomass of an ecosystem is combusted. It can cause the death of a dominant species.

— Pollution- It occurs when chemicals are present in concentrations large enough to affect organisms and thereby cause ecological changes. Nutrients such as phosphate and nitrate when introduced into the environment can influence productivity and other ecological processes. This type of pollution is known as eutrophication.

— Thermal stress- It occurs when heat releases influence ecosystems.

Example: as seen in the vicinity of natural hot-water vents on the ocean floor. A more prominent example is areas where industries discharge heated water.

— Radiation stress- It is connected to excessive loads of ionizing energy.

Example: on mountain tops with high exposure to ultraviolet radiation. Also, at places where there are exposures to radioactive materials.

— Climatic stress- It is connected with excessive or insufficient regimes of temperature, moisture, solar radiation, and combinations of these.

Example: Tundra and deserts are examples of climatically stressed ecosystems.

 — Biological stress- It is associated with the diverse interactions that occur among organisms of the same or different species.

Example: the harvesting and management of species and ecosystems by humans.

(Note: biological pollution-The introduction of invasive, non-native species.)

Point to ponder: What is ecosystem integrity?

(Sources: link.springer.com, environreview.com.ng)