A Healthy Earth (Leaving Cert CASD): Revision Notes

Ecosystem Investigation

What is ecosystem investigation?

Understanding how our local environment works is crucial for protecting it. An ecosystem represents the complex web of relationships between all living things and their physical surroundings. When we investigate ecosystems, we're essentially becoming environmental detectives, gathering evidence about how human activities and natural factors affect the health of our local environment.

Local ecosystem investigations help us understand the real-world impact of environmental pressures like pollution, climate change, and human development. As a student investigator, you'll learn to collect your own data and propose practical solutions to protect these vital systems.

Understanding your data sources

Before diving into fieldwork, it's important to understand the types of information you'll be working with:

Primary data is information you collect yourself through direct observation, measurement, and surveys in the field. This might include pH measurements you take from a local stream or species counts from a woodland area. This data is valuable because it's current, specific to your study area, and gives you hands-on experience with scientific methods.

Secondary data comes from existing sources like government environmental reports, scientific databases, or previous research studies. While you didn't collect this information yourself, it provides valuable context and allows you to compare your findings with larger patterns.

Air ecosystem investigation

Air quality directly affects both human health and ecosystem stability. Urban areas often experience elevated pollution levels from traffic, industry, and heating systems, making air ecosystem studies particularly relevant for students.

Investigating air pollution impacts

When studying air ecosystems, focus on air pollution as your primary environmental factor. Pollution sources include vehicle emissions, industrial processes, and fossil fuel combustion. These activities release harmful substances that can damage both living organisms and the broader ecosystem.

Collecting air quality data

Your investigation should combine measurable data with observational evidence:

Drawing conclusions and taking action

Compare your data from different locations to identify patterns. Areas with higher traffic or industrial activity typically show elevated pollution levels and fewer pollution-sensitive species like lichens.

Effective protection strategies include:

• Increasing tree coverage to naturally absorb carbon dioxide and philtre pollutants

• Promoting sustainable transport through better cycling infrastructure and public transport

• Supporting renewable energy initiatives to reduce fossil fuel dependence

Soil ecosystem investigation

Healthy soil forms the foundation of terrestrial ecosystems, supporting plant growth and providing habitat for countless organisms. Soil investigations help us understand how human activities affect this critical resource.

Investigating soil health factors

Focus on soil compaction and contamination as key environmental pressures. These problems often result from intensive agriculture, construction activities, littering, and inappropriate land use practices.

Collecting soil data

Effective soil investigations require both chemical and biological assessments:

Analysis and protection strategies

Compare data from undisturbed areas (like established gardens) with disturbed locations (such as heavily trafficked areas). Healthy soils typically show neutral pH, good drainage, and abundant biological activity.

Key soil protection approaches include:

• Composting and organic gardening to improve soil structure and fertility naturally

• Reducing chemical inputs by minimising pesticide and synthetic fertiliser use

• Preventing erosion through cover crops and appropriate vegetation management

Water ecosystem investigation

Freshwater ecosystems are particularly vulnerable to pollution and climate change impacts. Water investigations help us understand how human activities affect aquatic life and water quality.

Investigating water quality factors

Focus on water pollution and temperature changes in local rivers, ponds, or lakes. These changes can result from agricultural runoff, urban drainage, industrial discharge, and climate change effects.

Water quality data collection

Comprehensive water studies combine chemical testing with biological surveys:

Understanding water ecosystem health

Higher pollution levels typically reduce biodiversity and affect water clarity, temperature, and chemical balance. Clean water ecosystems support diverse invertebrate communities and maintain stable chemical conditions.

Effective water protection strategies include:

• Reducing agricultural runoff by controlling fertiliser application and creating buffer strips along waterways

• Preventing littering through community education and regular clean-up activities

• Monitoring industrial discharge to ensure proper wastewater treatment

Biodiversity investigation

Biodiversity studies examine the variety and abundance of species in different habitats. These investigations help us understand how environmental pressures affect ecosystem complexity and stability.

Investigating biodiversity pressures

Focus on habitat loss, invasive species, and human disturbance as primary factors affecting local biodiversity. Development, pollution, and climate change can dramatically alter species communities.

Biodiversity survey methods

Effective biodiversity studies use standardised sampling techniques:

Biodiversity conservation actions

Compare species richness between disturbed and undisturbed areas to understand human impact patterns. Generally, undisturbed habitats support more diverse and stable species communities.

Key conservation strategies include:

• Creating wildlife corridors and installing nesting boxes to provide habitat connectivity

• Removing invasive species that outcompete native plants and animals

• Supporting habitat restoration through rewilding and tree-planting programmes

Data collection techniques and survey methods

Successful ecosystem investigations depend on using appropriate survey methods and understanding different data types.

Qualitative versus quantitative approaches

Qualitative data involves descriptive observations that help you understand ecosystem conditions. Examples include noting the presence or absence of indicator species, describing water clarity, or observing animal behaviour patterns.

Quantitative data provides numerical measurements that allow for statistical analysis and comparison. This includes species counts, pH readings, temperature measurements, and percentage coverage calculations.

Essential survey techniques

Different ecosystems require specific survey methods:

• Quadrats are square frames used for sampling plants and small organisms in a defined area

• Transects involve systematic sampling along predetermined lines through habitats

• Kick sampling stirs up riverbed sediments to collect aquatic invertebrates

• Pitfall traps are containers placed in soil to capture ground-dwelling insects

• Air sensors and diffusion tubes measure atmospheric pollutant concentrations

• Water testing kits assess chemical parameters like pH, turbidity, and nutrient levels

Exam preparation tips

Understanding how to present your ecosystem investigation effectively is crucial for exam success:

• Always identify the environmental factor you're investigating (such as air pollution, soil contamination, or habitat loss)

• Describe your primary data collection method clearly, explaining why you chose specific techniques

• Present findings using appropriate visual aids like graphs, tables, or maps to make patterns clear

• Link your results to ecosystem health conclusions by explaining what your data reveals about environmental conditions

• Suggest practical protection actions that directly address the environmental pressures you've identified