Ecology

What is Ecology? The study of interactions between organisms and how they relate to the physical environment.

Levels of Ecological Organization Species: group, which can mate and produce fertile offspring .

Levels of Ecological Organization Population - all the members of a species inhabiting a given location.

Levels of Ecological Organization Community - all the interacting populations in a given area.

Ecosystem - the living community and physical environment functioning together as an interdependent, self sufficient, stable system. Ecosystem requirements - Energy source - Energy flow and storage in organic compounds - Cycling of material

Levels of Ecological Organization Biome: A group of ecosystems with similar flora, fauna and climate.

Levels of Organization Biosphere - the portion of the earth in which life exists

Abiotic and Biotic Components of an Ecosystem Abiotic Factors - include physical and chemical factors which affect the survival of organisms. Ex: Light intensity Temp. range pH. Supply of gases Amount of moisture Types of soil or rock Availability of minerals.

Biotic Factors Biotic Factors - all the living things that directly or indirectly affect the environment. Ex: organisms and their : Interactions Parts Wastes

Nutritional Relationships . Autotrophs Heterotrophs synthesize their own food from inorganic raw materials (H2O and CO2) Photosynthesis cannot make their own food, and must ingest preformed organic matter.

Types of Heterotrophs

Saprophytes Saprophytes (Decomposers)- heterotrophic plants, fungi or bacteria that live off dead organic matter

Herbivores Herbivores - animals that consume plants

Carnivores Carnivores - eat other animals Predators - kill their own prey Scavengers - feed on dead animals they did not kill Omnivores - eat both plants and animals

Symbiotic Relationships Symbiotic Relationships – include different organisms living together in a close association.

1. Commensalism - one organism is benefited and the other is not affected (+, 0) ex. Barnacles on a whale Shark and Remora Fish

2. Mutualism - both organisms benefit (+,+) ex. Lichens. A lichen is a cross between an algae and a fungi. Both organisms benefit from the relationship

Parasitism - the parasite benefits at the expense of the host (+,-) ex. The male angler fish on the female angler.

Energy Flow in an Ecosystem All organisms need energy for their metabolic activities Food Chain- Displays a one way relationship of energy flow in an ecosystem

Food Web Shows the interrelationship between food chains.

Food Web Interactions Producers – Organisms that manufacture their own food. Consumers – 1. Primary consumers - herbivores. 2. Secondary consumers – carnivores, feed on other consumers. 3. Tertiary consumers- carnivores that feed on the secondary consumers. 4. Quarternary Consumers- Top order consumers, food chains or food webs rarely extend beyond a quarternary consumer because energy is lost. Decomposers – organisms of decay break down organic wastes and dead organisms into simpler substances (bacteria, fungi). ** Decomposers return chemical substances to the environment for reuse.

Energy Pyramid Pyramid of Energy - there is much more energy at the producer level of a food web than the consumer level. A pyramid can be used to show this energy loss: Top order Consumer Energy decreases as you climb the pyramid Biomass decreases as you climb the pyramid Secondary Consumer Primary Consumers Producers

Pyramid Facts Only 10% of ingested nutrients are used to build new tissue (Food for next feeding level). 90% is lost as heat energy Eventually the energy in and ecosystem is lost, thus it must have a constant input of energy from the sun. Biomass Pyramid - The decrease of energy at each successive feeding level means that less biomass can be supported at each level.

Material Cycles In a self-sustained ecosystem materials must be recycled for reuse. Carbon Hydrogen Oxygen Cycle (C-H-O) involves the process of photosynthesis and respiration.

Water Cycle - involves photosynthesis, transpiration, evaporation, condensation, respiration, and excretion. Respiration Transpiration

Nitrogen Cycle - plants need nitrogen to make plant proteins. Plants obtain Nitrogen from the soil, or from nitrogen fixing bacteria that change atmospheric N2 into a form usable by plants. Animals obtain nitrogen by eating plants, or animals that ate plants. Bacteria of Decay - break down and convert wastes and dead organisms into materials used by plants (nitrates and nitrites)

Nitrogen Cycle

Ecosystem Formation Ecosystems change with time until a stable system is formed.

1. Pioneer Organism: Organism that is first to inhabit an area Ecological Succession - the replacement of one community by another until a stable climax community is reached. Succession begins with pioneer organisms and finishes with a climax community 1. Pioneer Organism: Organism that is first to inhabit an area Ex: lichens on bare rock 2. Climax Community: A stable ecological community in which little change occurs. Ex. A hardwood forest Oak-hickory and hemlock-beech-maple, represent climax communities found in N.Y. State.

LIMITING FACTOR Any abiotic factor that limits the size of a population Ex: low temp may limit type of plant or animal life in an area. Ex: the amount of dissolved oxygen may limit the number of, or the species of fish that can survive. Carrying Capacity – the number of organisms of any single species that an ecosystem can support

Carrying Capacity

Competition - occurs when different species living in the same habitat use the same limited resources such as food, space, water, etc. If two or more groups have the exact same role in the ecosystem then they are said to share the same NICHE. Niche – the role an organism plays in a community During competition a species may be eliminated. This usually establishes one species per niche.

Growth of Human Population What factors have contributed to this exponential growth?

Warbler Niches Habitat – the environment an organism lives in.

Limiting Factors and Carrying Capacity

Biosphere and Humans Human's unique and powerful influence on the physical and living world, have changed the environment with some positive and negative effects. I. Negative Aspects 1. Human Population Growth - has exceeded the food producing capacity of many ecosystems.

2. Over hunting - has resulted in the extinction of some species. 3. Importation of Organisms - importing organisms, which have no natural enemies, can disrupt an ecosystem. 4. Exploitation of Wildlife - both flora and fauna can disrupt an ecosystem. 5. Poor land use and management - increased urbanization has resulted in less farmland and natural habitats for wildlife.

6. Loss of Biodiversity – can effect the stability of an ecosystem. 7. Technological oversights - have led to pollution of water, land, and air. Water pollutants Heat - reduces dissolved oxygen Sewage Chemicals Heavy metals

Air pollutants Carbon dioxide – Is a major contributor to the Greenhouse effect Hydrocarbons Nitrogen oxides - causes acid rain Sulfur dioxide - causes acid rain

8. Disposal of non-biodegradable wastes has also become a major solid waste disposal problem. II. Positive Aspects Increased awareness has led to the prevention of negative disruption to the environment. 1. Population Control

Conservation of resources - Erosion control (reforestation and overcroping) - Water and energy conservation - Recycling 3. Pollution Control - of water and air are being attempted by forming laws and new techniques of sanitation

4. Species preservation - habitat 4. Species preservation - habitat protection such as national parks and wildlife refuges have helped endangered species. 5. Biological Control - of insect pests does not disrupt food webs and contaminate the earth. Ex: sex hormones, natural parasites