Ecological Management

The relationships between plants and animals in their environment are known as biotic interactions or associations. These interactions closely link the biotic and abiotic components of the environment, which influence one another and are essential for maintaining ecosystem balance.

Symbiosis

Symbiosis refers to a close relationship between two organisms in which one or both benefit. Each participant in this association is called a symbiont. Symbiosis can be categorized into the following types:

1. Mutualism
2. Commensalism
3. Parasitism

Mutualism

Mutualism is an interaction where both species benefit, with neither being harmed. Most mutualistic relationships are facultative, meaning the species can live independently. However, some relationships are obligate, where the species are so interdependent that they cannot survive without each other.

Examples of mutualism include:

1. Legumes and nitrogen-fixing bacteria (rhizobia) in their root nodules
2. Termites and the protozoa in their gut
3. Bacteria in the rumen of ruminants

Commensalism

Commensalism is a relationship where one species benefits while the other is neither helped nor harmed. Although such relationships can be difficult to prove, they highlight the complexity of ecological interactions.

Examples of commensalism include:

1. Trees and epiphytes, where epiphytes use tree trunks for support
2. Certain bacteria in the human large intestine that feed on leftover food

Parasitism

Parasitism is a relationship where one species (the parasite) benefits at the expense of the other (the host). Parasites derive food, oxygen, living space, or support from their host, often causing harm. Parasites can also act as vectors, transmitting diseases to other organisms.

Types of parasites:

• Ectoparasites: Live on the external surfaces of the host, e.g., ticks, lice, and dodder plants
• Endoparasites: Live inside the host, e.g., tapeworms, roundworms, malaria parasites, and bacteriophages (viruses targeting bacteria)

Examples of parasitism:

1. Mosquitoes feeding on human blood
2. Hookworms or roundworms in the human digestive tract
3. Fleas feeding on the blood of dogs

Competition

Competition occurs when two or more organisms require the same resource for survival. This can occur among organisms of the same species or different species. Common resources involved in competition include food, water, sunlight, shelter, and space.

Predation

Predation involves one organism (the predator) hunting, killing, and consuming another organism (the prey). This interaction helps regulate populations and maintain ecosystem balance. Examples include lions hunting antelopes and hawks preying on mice.

Tolerance

Tolerance refers to the ability of organisms to withstand unfavorable environmental changes that affect their survival. Living organisms can endure minor shifts in biotic and abiotic factors, which are critical for their survival.

Tolerance Range

Organisms have a range of environmental conditions they can tolerate, known as their tolerance range. Survival becomes impossible beyond this range. For instance, most animals have a tolerance range for temperature between 0°C and 42°C. Below 0°C or above 42°C, survival is unlikely.

The concept of tolerance is closely linked to an organism's physiological and ecological adaptations. Some species are better suited to specific conditions, while others may struggle to survive.

Geographical Tolerance

Geographical tolerance refers to the areas where a species can exist within its minimum and maximum tolerance limits. This distribution is studied under biogeography, which examines the geographical spread of plants and animals. Variations in abiotic factors contribute to the formation of biomes such as tropical rainforests, savannas, deserts, and aquatic ecosystems, each supporting unique species in microhabitats.

An organism's ecological niche includes its habitat, activities, requirements, and impact on the environment.