Applied Ecology

1. Applied Ecology

2. Contents • Diversity • Effects of Pollution on Diversity • Structural, Physiological and Behavioural Adaptations of Organisms for Survival in a Given Niche • Agricultural Ecosystems • Harvesting from a Natural Ecosystem • Conservation

3. Diversity • Depends on: - number of species and abundance of each species in an ecosystem • Growth of population depends on: - Abiotic factors - Biotic factors Index of Diversity: d = N(N-1)/Σn(n-1) d: index of diversity N: total number of organisms of all species in area n: total number of organisms of each species in area

4. Impact of Humans • Humans pose a huge threat to lives of animals, plants and their environment • Our impact is so great due to: - technologies that change the world so quickly - population increase - consumption of natural resources, and waste

5. Human Population Growth • Humans can adapt to survive in almost all habitats and climates. The human population is increasing rapidly and is threatening the environment • The population will eventually be limited by these factors: - food and water supply - disease and pollution - over-crowding - sudden changes in climate

6. Pollution • Atmospheric: Caused by combustion, exhaust fumes, livestock, waste dumps • Effects: - smoke, which damages air quality - carbon dioxide and Methane, which cause climate change - sulphur dioxide and nitrogen dioxide, which mix with rainwater to form acid rain - carbon monoxide, which is poisonous to humans and animals • Water: Caused by deposition of substances into seas, lakes, rivers • Effects: - sewage and oil, which destroy habitats and kill animals - fertilisers and pesticides, which damage ecosystems

7. Examples of Relationships (Interactions) Between Species Ecological Niche • Describes how organisms in an ecosystem interact • What it does that affects or contributes to its surroundings • Includes: habitat, relationships and nutrition

8. Agroecosystems • Definition: formed by interactions between biotic (plants, microbes etc.) and abiotic (temp. humidity etc.) factors in a defined area, an agroecostystem influences the distribution and population of living organisms • Tends to minimise human impact • Differs from natural ecosystems: - maintenance at an early successional state - monoculture - crops planted in rows - simplification of biodiversity - intensive tillage - use of GM organisms and artificially selected crops

9. Agroecosystems • Refers to the study of an ecological phenomenon in the crop field e.g. relations between predators and prey • Needs energy input to maintain a balance e.g. use of pesticides disturbs balance by killing organisms • Maintenance keeps pest populations at manageable levels: - ecosystems are ever changing systems - ecosystems follow food webs - All elements of an agroecosystem are closely linked. Disturbance to one has effects on others

10. Harvesting from a Natural Ecosystem • Humans have a huge impact on the planet. This includes intensive farming, selective breeding and pesticides/fertilisers • Impacts of Monoculture: • Genetic diversity is reduced, crops susceptible to disease • Fertilisers pollute groundwater • Pesticides pollute groundwater • Species diversity is reduced • Countryside less attractive • Crop rotation: breaks pests’ life cycles, improves soil texture and can increase soil nitrogen

11. Harvesting from a Natural Ecosystem • Hedgerows have been diminishing due to human need for barren land • Benefits of hedgerows to ecosystem: • Provide habitats • Animals use them to move safely between woodlands • Shelter predators of pests • Windbreaks, shelter, reduce soil erosion • Provide habitats for pollinating insects • Importance is now being recognised and farmers are receiving grants to plant hedgerows

12. Harvesting from a Natural Ecosystem • Inorganic fertilisers are most common but affect the environment • Benefits of organic fertilisers to ecosystem: • Compounds decompose slowly and prevent leaching • They are cheap • Can be disposed of on fields and not only in landfill sites • Improves soil structure and improves drainage and aeration • But… bulky and less concentrated than inorganic ones, highly odorous and can contain weed seeds etc.

13. Harvesting from a Natural Ecosystem • Intensive farming can damage the environment. e.g.

14. Harvesting from a Natural Ecosystem • Pesticides can harm larger organisms. e.g.

15. Harvesting from a Natural Ecosystem • Fishing: Unsustainability: the using up of resources faster than they are produced so that they will not continue in the future e.g. North Sea Cod are over-fished so are reproducing slower than are being caught. Effect  population is heavily declining • Forestry: Humans burn wood or clear land for farming  deforestation: 1) destroys habitats 2) causes soil erosion  barren land and flooding 3) causes pollution from combustion 4) increased levels of carbon dioxide as loss of photosynthesis

16. Conservation • Humans recognise the necessity to maintain a balance between the needs of ourselves and other species • Conservation of forests: encouragement of sustainable use of forests • Governments must be persuaded that more money can often be made by exploiting forests on a sustainable basis than by destroying them

17. Summary • Diversity • Effects of Pollution on Diversity • Structural, Physiological and Behavioural Adaptations of Organisms for Survival in a Given Niche • Agricultural Ecosystems • Harvesting from a Natural Ecosystem • Conservation