Explain the following words as used in ecology: (i) Ecosystem - Leaving Cert Biology - Question 13 - 2015

A community in ecology refers to all the different populations of various species that coexist and interact within a particular environment. These interactions can be competitive, predatory, or symbiotic, and the community contributes to the overall health and stability of the ecosystem.

Fauna encompasses all animal life, typically found in a specific region or habitat. This term is used to classify and study the diversity of animal species within particular ecosystems, highlighting the roles they play in ecological interactions.

One predator I studied is the great horned owl from the temperate forest ecosystem. An adaptive feature of this predator is its excellent night vision, allowing it to hunt effectively during the night when its prey, such as small mammals, is more active.

Variation refers to differences among individuals within a population or species. These differences can be due to genetic factors as well as environmental influences, leading to a range of phenotypes.

Variation in plant height can occur due to several factors, including genetic diversity within the species, differences in available nutrients in the soil, variations in water availability, and exposure to sunlight.

A - Large producer (e.g., oak tree), B - Named larger herbivore (e.g., deer), C - Named smaller herbivore (e.g., rabbit), D - Parasite (e.g., insect feeding on plant).

The organism named at point B is most likely to be a herbivore, as it consumes plant material.

Energy loss at each trophic level limits the length of food chains; as energy is lost primarily as heat, the available energy diminishes, making it insufficient to support many levels.

As energy decreases, fewer organisms can be sustained at the final trophic level; thus, typically, there are fewer top predators.

Some decomposer species may not be able to occupy the vacant niche due to specialized adaptations that are specific to particular environmental conditions or available resources that differ from their own needs.

The introduction of non-native animals can disrupt local ecosystems, outcompete native species for resources, introduce diseases, and threaten the balance of existing food chains.

Using small mesh sizes can lead to the capture of juvenile fish, disrupting fish populations and preventing them from reaching maturity and reproducing, which threatens species sustainability.

Cutting hedgerows during these seasons can destroy nesting sites for birds and disrupt the life cycles of many insects, leading to declines in biodiversity.

Spreading slurry can lead to runoff that pollutes waterways, causing algal blooms that deplete oxygen levels and harm aquatic life, alongside the potential risks of pathogens being introduced to the water supply.