Ecology

What’s Ecology? Branch of biology that deals with the interactions among organisms and the interrelationships of the biological and physical environment in which they live. Biological environment: made up of plants and animals (all things living) Physical environment: made up of light, heat, moisture, wind, oxygen, carbon dioxide, soil nutrients, and atmosphere (non-living things…everything else)

Levels of Organization Organisms and the environment are studied at levels. Each level includes different factors… Species (organisms of the same kind)…which make up… Populations (members of the same species that live in a certain area)…which make up… Communities (populations living in a given area)…which make up… Ecosystems & Biomes (include all the communities & the physical environment functioning together)…which make up… Biosphere (part of the Earth upon which life exists)

Ecosystems They are the level of organization that Ecologists use to study the environment They includes Biotic (living) and Abiotic Factors (non-living). Requirements for a Stable Ecosystem: Need a constant supply of energy There must be living organisms that can use the energy to make organic compounds There must be a recycling of materials b/w organisms and the environment

Biotic Factors in an Ecosystem These are all the living things that affect an ecosystem There are 3 divisions of the biotic factors: Producers: organisms that make their own food. (ex.) plants

2. Consumers: organisms that eat producers and/ or other animals (ex 2. Consumers: organisms that eat producers and/ or other animals (ex.) animals 3. Decomposers: organisms that break down dead organisms and make their materials available to other living things (ex.) bacteria, saprophytic fungi

Abiotic Factors in an Ecosystem These are all the non-living things that affect an ecosystem. They directly affect an organism’s ability to live and reproduce in an environment. Soil: such as sand, clay, rock, swamp, acidic, alkaline, loam Water Air: gases such as oxygen, carbon dioxide, nitrogen, hydrogen Light Temperature Minerals: such as nitrogen, sodium, calcium, carbon, iron, potassium

Biomes The biosphere is organized into units called Biomes. Biome: large geographic area of earth identified by a particular type of dominant plant/animal life Two types… Terrestrial (land) Aquatic (water)

Biomes The biosphere is organized into units called Biomes. Biome: large geographic area of earth identified by a particular type of dominant plant/animal life Two types… Terrestrial (land) Aquatic (water)

Terrestrial Biomes Tundra: frozen subsoil 2. Taiga: long, sever winters, summers with thawing of subsoil

3. Temperate Deciduous Forest: moderate rain, cold winters, warm summers 4. Tropical Rain Forest: heavy rainfall, constant warmth

5. Grassland: variability in rainfall and temperature. Strong winds. 6. Desert: little rainfall, extreme daily temperature changes

Aquatic Biomes 1. Marine/salt water 2. Fresh water …they make up the Earth’s largest ecosystem. 70% of Earth’s surface is covered by water and more organisms live in water than on land.

Factors Affecting Water Biomes Amounts of available oxygen and carbon dioxide Temperature and light Amounts of dissolved minerals and suspended particles

Energy & Nutritional Relationships You’re either an autotroph (producer) or a heterotroph (consumer/decomposer) when it comes to obtaining energy/food. Different Types of Heterotrophs: Saprophytes: These are the decomposers. Include plants, fungi, bacteria Herbivores: animals that eat producers (plants) only Carnivores: animals that eat other animals only A. Predators…kill their prey/food B. Scavengers…feed off dead animals 4. Omnivores: animals that eat both plants and animals

Symbiotic Relationships Symbiosis is an example of how organisms interact with each other and with their environment. In symbiosis different species live together and at least one species benefits from it. Three Examples of Symbiotic Relationships: Mutualism: when both organisms benefit Commensalism: one benefits and the other is not affected in any way Parasitism: one benefits (the parasite) and the other (the host) is harmed

Food Chains & Webs Ecosystems need a constant supply of energy and organisms that can use the energy to make organic compounds/ nutrients The pathway of energy flow is represented by food chains/webs… Producer… to… Primary consumer… to… Secondary consumer… to… Higher-level consumer… to … Ecosystem

Pyramid of Energy The amount of available energy/food for an organism decreases at each higher level in a food chain/web This is because at each level more energy is lost as heat

Pyramid of Biomass Biomass: amount of organic matter in an ecosystem… The total amount of biomass an ecosystem can support decreases at each higher feeding level! This is because there is less energy available at each level for organisms to successfully survive!

Material Cycles The atoms and molecules on Earth cycle around living & non-living things. This is an example of how materials get recycled b/w the living and non-living environment. Three Different Cycles: Carbon-Oxygen Cycle Water Cycle Nitrogen Cycle

The Carbon - Oxygen Cycle Involves cellular respiration & photosynthesis (oxygen and carbon dioxide gases)

The Water Cycle Involves the evaporation and condensation of water

The Nitrogen Cycle Nitrogenous wastes and the remains of decayed organisms are converted by decomposers into compounds that can be used by autotrophs

Populations & Communities…Vocabulary Habitat: the place in an ecosystem where an organism lives Niche: is the role an organism plays in its ecosystem Stable Population: under stable environmental conditions, the # of organisms remains constant with small periodic changes. Limiting Factors: factors that reduce population growth (ex.) food, water, disease, predators, amount of living space available

Unstable Population: a drastically reduced number of organisms. (ex Unstable Population: a drastically reduced number of organisms. (ex.) endangered species Exploding Populations: the rapid reproduction of organisms, usually followed by a rapid decline (due to limiting factors). (ex.) algae blooms in lakes Carrying Capacity: the number of organisms any habitat can support Ecological Succesion: the change that a community undergoes over time - Climax Community: term given to the stable community that has taken over another community over time - Pioneer organisms: term given to the 1st organisms to populate a given area

Stages of Ecological Succession

Human Impact on the Environment The human population differs from all other organisms in its ability to change the environment. Human activities have upset ecosystems and have had negative environmental impacts on both biotic and abiotic factors. In order to survive as a species, humans need to understand that they interact with many different biotic & abiotic factors. Human activities can deliberately or inadvertently alter the equilibrium in ecosystems Resolving these issues requires increasing global awareness, cooperation, and action.

Human Survival Requirements: Clean air & water Nutritious food Fertile soil Space for shelter and living

Environmental Concerns 1. Population Growth: Human population growth is not stable, its been growing rapidly Is due to advances in medical knowledge and education Many ecosystems are unable to produce enough food resulting in starvation in certain countries Scientists believe humans are reaching the limits of their ability to increase as a species b/c requirements won’t be met due to limiting factors

The massive increase in human population size has lead to: Pollution Deforestation Global warming/Greenhouse effect Deterioration of the ozone layer (shield)

2. Environmental Pollution Pollutant: something that is put in the air, water, soil that makes it dirty and unfit for living things Substances become pollutants when they exceed the capacity of ecosystems to break them down, or they cannot be broken down and are toxic. Three Major Environmental Pollutants: Water pollution: pollutants – heat, pesticides, sewage, heavy metals, chemicals. Air pollution: pollutants – FOSSIL FUELS: (petroleum, coal, natural gas): GLOBAL WARMING/GREENHOUSE EFFECT (caused by too much carbon dioxide in air) ACID RAIN ( nitrogen oxides combine w/ water vapor)

3. Soil Pollution: pollutants – organic & inorganic chemicals, solid wastes, pesticides 3. Human Activities Humans must become environmentally literate b/c our activities affect the lives of other organisms Some organisms depend on us for their survival (ex.) English sparrow (needs us for nesting purposes) & mayfly (is food to game fish) Whales, whooping cranes and bald eagles have been negatively affected by humans

Extinction (ex. Dodo bird, passenger pigeon) has occurred as well as a rise of endangered species (ex. Blue whale). Possible causes: -overhunting -exploitation (selfish use) -poor land management -importation or organisms (no natural enemies) -use of biocides (ex. DDT)

A. Biocide Use Biocide: a chemical that is used to kill “undesirable” living thing like insects, weeds (ex. pesticides - (DDT), herbicides) Such chemicals can contaminate the soil, air, and water supply and disturb food chains DDT was responsible for the endangered status of the bald eagle Spraying of DDT was banned in 1973

B. Waste Disposal Solid wastes: Biodegradable: wastes that can be broken down naturally by microorganisms into harmless materials and then recycled and reused by organisms (ex. cotton, paper) Non-biodegradable: cannot be broken down (ex. plastic, glass, aluminum, disposable diapers)

C. Technology Technology: the use of tools, machines, inventions to do work and solve problems Industrialization has caused an increase in demand for and use of energy, fossil & nuclear fuels. Has had positive and negative effects on ecosystems and has changed the abiotic environment drastically Negative affects: - burning of fossil fuels– has added to air & water pollution. - Acid rain and the green house effect/global warming due to industrialization

Improving The Environment Population growth and environmental pollution will be limiting factors for the human species if they are not slowed down Environmental Laws: Laws aimed to stop pollution Encourage the development of new techniques for handling situations Freshwater Wetland Act Hazardous Waste Disposal Regulation Air pollution Control Laws State Environmental Quality Review (SEQR) Act Returnable Container Law Endangered Species Act

Conservation of Natural Resources Protection and wise use of natural resources (soil, water, air, energy, wildlife, open space) Renewable resources (ex. water, air, soil, plants, animals) – can be reused or replaced. Finite Resources (ex. fossil fuels & mineral deposits) – limited in supply and can’t be replaced. We now RECYCLE non-renewable resources as a conservation method and use WATERSHEDS to control the wasteful runoff of rain water.

Poor Land Management Rise of cities and suburban areas has reduced the land available for agriculture and disrupted the habitats of many organisms Some attempts to increase agricultural productivity have had negative affects… direct harvesting over cropping overgrazing failure to use cover crops …these practices have lead to erosion (wearing away of soil to wind & water) and loss of topsoil.

Things we’ve done to fix the matter… reforestation (replanting forests) growing cover crops (ex. alfalfa & clover) strip cropping terracing contour plowing

Wildlife Preservation The helping of endangered species Wildlife refuges and national parks help provide habitats Laws are passed to regulate over-hunting/over-fishing

Biological Pest Controls Substitutions of non-chemical or biological methods of pest control are being made over chemical methods Biological methods are less likely to affect the ecosystem negatively Methods of Biological Pest Control: Sex Hormones Natural predators or parasites Breeding pest resistant plants Releasing sterilized male insects