10. (a) (i) What is the precise meaning of the term niche as used by ecologists? (ii) From your investigations of a named ecosystem, give one example each of: 1 - Leaving Cert Biology - Question 10 - 2016

An example of a safety hazard in a named ecosystem, such as a forest, could be fallen branches or slippery terrain due to wet conditions, which may cause accidents during fieldwork.

A source of error could be misidentifying species during data collection, which could lead to inaccurate conclusions and affect the integrity of the study.

For the collection of fauna in a named ecosystem, I used pitfall traps, which involved setting up containers in the ground to capture small animals such as insects and amphibians.

The identification of the collected fauna was carried out using a key and photographs from relevant field guides to ensure accurate classification of the species.

The quantitative study of a named plant species was conducted by using random quadrats placed throughout the ecosystem to count the density of the species. Ensuring randomness involved using a random number generator to select quadrat locations.

Using a random sampling technique is essential to prevent bias in data collection. It ensures that every individual in the population has an equal chance of being selected, leading to more reliable and representative results.

1. Soil pH: Variations in soil acidity can influence plant growth and distribution.
2. Water availability: The amount of water in the soil affects plant survival and can limit distribution in arid environments.

Human activity, such as urban development or agriculture, can lead to habitat destruction, which reduces biodiversity and alters the ecosystem's structure.

The trophic level refers to the position an organism occupies in a food chain, indicating its role in the flow of energy and nutrients. Levels include primary producers, primary consumers, secondary consumers, and higher-level consumers.

Food chains are generally short because of energy loss at each trophic level. Typically, only about 10% of the energy is available to the next level due to metabolic processes, limiting the number of levels.

In the food chain A → B → C → D, the letter C represents the secondary consumer.

The population of C may decline naturally due to predation from a higher trophic level, such as D, or factors like disease that affect overall health and survival.

If the population of C is significantly reduced, the population of D may increase due to a decrease in predation pressure. This could lead to overpopulation of D, resulting in increased competition for resources and potential imbalance in the ecosystem.

The secondary consumer in the given food chain can be a primary consumer in another chain if it primarily feeds on a different type of organism, such as a plant. This flexibility allows species to occupy different roles based on available resources in their environment.