Transcript Ecology
Ecology is the study of interactions among organisms and their environment. Ecologists are scientists who study these relationships. Ecologists divide the environmental factors that influence organisms into two groups (abiotic and biotic factors). Many times, ecologists must travel to specific environments to examine the organisms that live there. Biome - a large geographical area having the same climate and major life forms. A ecosystem is a group of organisms & their physical environment. In an ecosystem you have three classes of consumers: Herbivore - eats plants only Carnivore - eats meat Omnivore - eats both A habitat is where an organism lives within an ecosystem. An ecosystem is the biotic community and its abiotic factors. Examples of ecosystems include coral reefs, forests, and ponds. The carrying capacity is the maximum population size that can live in an environment over time. A limiting factor is a biotic or abiotic factor that restricts the size of a population. •Food can be a limiting factor if the amount of food can only support a certain number of an animal in a population. Biotic factors are the living or once-living parts of the environment (plants, animalsprey, etc) Abiotic factors are the nonliving parts of the environment (light, water, air, nutrients, soil, minerals, nesting sites) What are the biotic and abiotic factors in this picture? http://www.thegardenhelper.com/102902.JPG Cows Air Grass Water Trees Soil, Shrubs Light Others unseen rocks Temperature The total number of species and biological communities in a region and the amount of genetic variation in each species The loss of biodiversity is a huge ecological problem Genetic diversity decreases as its populations decline- consequences in a population to adapt to changing environment Genetic variability-measure of its potential to adapt; evolutionary insurance policy • • • • • Limit pollution (air, soil, water) Control transport of invasive species Limit the use of natural resources (clear cutting rainforests, interfering with river flow to wetlands, slow down oil and gas consumption) Conserve natural resources Protect endangered species (plants and animals) The interaction between two or more organisms, or groups of organisms, that compete for the same resources (in short supply) Can be between members of the same species and/or members of the different species Most important aspects of natural selection Results: reduction in the numbers of one or both competitorsDistribution of organisms in habitats A living thing that makes food using materials from the environment (nutrients) & the Sun. Primary - uses food produced by plants (eats plants) Secondary - obtains energy by eating primary consumer (eats meat) Living things that eat the remains and waste of plants and animals. Like bacteria, It breaks down organic material. Producers are plants: Grass Trees Flowers Weeds The produce energy through photosynthesis Consumers are animals (including humans): Bacteria (also decomposer) insects rodents dog/wolf/fox bears INTERACTIONS AMONG ORGANISMS Predator-prey An animal that hunts or kills other animals for food is called a predator. An animal that is eaten by another is called prey. Can you match some predatorprey relationships? Predator Prey Symbiosis Symbiosis is a long term relationship between 2 or more species - Mutualism – both organisms benefit ex. Coral (home) and algae (food) - Commensalism – One organism is helped, while the other is neither helped or harmed ex. Remoras ride on sharks and eat what they leave behind in food scraps - Parasitism – one benefits (parasite) the other is harmed (host) and weakened ex. ticks A living thing All organisms of the same species that live in the same place. Population that shares an area All populations within a certain area. Food Chain, Webs, and Pyramid ENERGY FLOW AMONG ORGANISMS Everything you do requires energy. How do you get the energy that you need? All living things get energy from their food to carry out life processes. Plants make their food. Animals eat their food. A food chain shows how each living thing gets its food. Plants make food using energy from the sun. Some animals eat plants and some animals eat other animals. Each link in a chain is food for the next link. Arrows indicate the direction of energy flow. A food chain is the passing of food energy from one organism to another. Plants are called producers because they are able to use the energy from the sun to produce the food they need using carbon dioxide and water. Animals cannot make their own food so they must eat plants and/or other animals. They are called consumers. There are three groups of consumers. HERBIVORES Animals that eat ONLY PLANTS are called herbivores. http://www.gpnc.org/pronghor.htm CARNIVORES Animals that eat OTHER ANIMALS are called carnivores. www.desertusa.com/ www.desertusa.com / http://www.orcahome.de/orcafa ct.htm OMNIVORES Animals that eat BOTH animals and plants are called omnivores. American bear http://animaltrial.com/animals/bearpicturesfolder /blackbearpictures/blackbearwalking.html Raccoon http://www.loomcom.com/raccoo ns/gallery/jpegs/raccoon1.jpg A herbivore is called a primary, or first order consumer because it eats the producers. A carnivore that eats herbivores is a secondary, or second order consumer. Some predators are called tertiary, or third order consumers. These animals usually have no predators. Some animals eat dead animals or carrion. They are called scavengers. They help break down or reduce organic material into smaller pieces. hyeina vulture roach http://pested.unl.edu/amerroa.jpg http://www.factmonster.com/i pka/A0768543.html http://www.mbr-pwrc.usgs.gov DECOMPOSERS Organisms (bacteria and fungi) which feed on decaying matter. Decomposers and scavengers break down dead plants and animals. They also break down the waste (feces) of other organisms. Decomposers are very important for any ecosystem. If they weren't in the ecosystem, the plants would not get essential nutrients, and dead matter and waste would pile up. Why are there more herbivores than carnivores? In a food chain, energy is passed from one link to the next. When a herbivore eats, only a fraction of the energy that it gets from the plant food becomes new body mass; the rest of the energy is lost as waste or converted to heat (by the herbivore). Likewise, when a carnivore eats another animal, only a portion of the energy from the animal food is stored in its tissues. In other words, organisms along a food chain pass on much less energy (in the form of body mass) than they receive. ENERGY PYRAMID Because a large amount of energy is lost at each link, the further along the food chain you go, the less energy is available. We use the energy pyramid as a model to show decreasing available energy at each level in the pyramid. 0.1% energy 1% energy 10% energy 100% energy FOOD WEBS Most organisms are part of more than one food chain. Many animals eat more than one kind of food in order to meet their food and energy requirements. These interconnected food chains form a food web. All energy comes from the sun - which makes it the MARINE FOOD WEB http://www.gould.edu.au/foodwebs/kids_web.htm Photosynthesis 6CO2 + 6H20 + energy (sunlight) Energy C6H12O6 (glucose)+ 6O2 from Sun is used to fuel a chemical reaction between carbon dioxide and water producing glucose Process which plants use CO2 from air to make sugars Reproduces Oxygen Makes food for energy Ecological Succession - the orderly changes in a ecosystem as one type of community changes into another Pioneer species – lichens and mosses – live in area and grow on rocks, releasing acids that break them down over time to form soil Plants start to grow in soil Small animals move into area Large animals feed on smaller animals Organisms die leaving richer soil supported larger plants – shrubs Soil becomes richer supporting trees Reaches a stable point of established growth know as a climax community