ECOLOGY ECOSYSTEMS AND THEIR INTERACTIONS ECOSYSTEMS A biological

ECOLOGY ECOSYSTEMS AND THEIR INTERACTIONS

ECOSYSTEMS: A biological community of interacting organisms and their physical environment (habitat) Include: Flora (plants & fungi) Fauna (animals) Lower life forms (protists & bacteria) Water & soil

HABITATS An organism’s physical environment Large habitat Atlantic Ocean Forests Jungles Small habitat – “microhabitat” Rotting Log Large Intestine Riffle, Run, or Pool in a Stream

BIOTIC FACTORS Living components of an ecosystem Animals, plants, fungi Predators Bacteria

ABIOTIC FACTORS Non-living Sunlight Air Water Minerals components in an ecosystem

ORGANIZATION IN THE ENVIRONMENT Organization Level 1. 2. 3. 4. 5. 6. Organism Population Community Ecosystem Biome Biosphere Example Human being Family Town People and buildings State of VT/US World/Planet

ORGANIZATION IN THE ENVIRONMENTEXPLAINED Population- a group of individuals of the same species that live together. Community- all the populations that live in an area and interact with each other. Ecosystems- made up of a community of organisms and the abiotic factors. Biosphere- The part of Earth where life exists.

BIOMES Earth’s biosphere is made up of different biomes Biomes are geographic areas with similar soil and climates Have similar species adaptations (Ex: Organisms living in Arctic biomes have thick fur &/or thick layer of blubber Common plants and animals characteristic of those climates. (Ex: Iguanas are found naturally in warm biomes because of their

INTERACTIONS WITHIN A COMMUNITY A community works like a team – each member has its own job to do but they are all connected. Interactions are driven by the need to obtain energy (eat!) Ex: In a forest community there are grasses, rabbits and foxes. Rabbits eat the grass. Foxes eat the rabbits. All the matter in every ecosystem is cycled between the air and soil among plants, animals, fungi & microbes

COMMUNITY MEMBERS Producers- the plants! Very important in an ecosystem, feeds the herbivores & omnivores. Consumers- eat the plants and other animals. Primary consumers- Insects that eat grass Secondary consumers- Birds that eat the insects Tertiary consumers- The fox that eats the bird Decomposers- Fungi & bacteria that break down dead matter. They recycle nutrients back into the ecosystem. Are also very important.

FOOD CHAINS • Food Chains show the path of energy through trophic levels, always beginning with producers

FOOD WEBS Much more complex Represents what actually happens in an Note how the arrows point- from what is being eaten to what eats it! ecosystem What is the abiotic factor that drives all food webs/ecosystems? (Hint: What do the plants need to obtain energy? ) What is missing from the food web? (Hint: how are nutrients recycled? )

ENERGY TRANSFERS & ECOLOGICAL PYRAMIDS Within an ecosystem’s consumers, energy is lost between each trophic level, but the amount of nutrients available stays the same. The law of conservation of energy states that energy, mass & matter is never lost, only converted into something else. The “lost” energy is changed into heat, which is given off by living things, and used for cellular respiration.

INTERDEPENDENT RELATIONSHIPS IN AN ECOSYSTEM In an ecosystem organisms may compete for resources, some may depend on another for their source of food, and others may help each other Competition- Fight other organisms for food, space, water, etc Symbiosis/Mutualism- both species benefit from the relationship Example- A hawk and owl both compete for mice, a maple and oak tree fight for light and water. One species will eventually lose, but both use up more energy during the “fight”. Example- A tree provides a place for lichens to grow on, also the algae in the lichen provide food and the lichen provides a home for the algae. Predation & Parasitism- Involves the killing and consuming of another, parasites need a host to feed on but does not usually kill. The host is weakened and usually can’t fight off infections or obtain energy. Predation example- A wolf consuming a deer Parasitism example- A tape worm in a dog’s intestines

PREDATOR - PREY RELATIONSHIPS There is a close interaction between predator & prey, each can influence the “fitness” of the other. If predators have more food available their numbers will increase. The increase in predators will then decrease the amount of food/prey available. The predators numbers will then begin to decrease. Once there are fewer predators, the food/prey population will increase. It’s a CYCLE!

CARRYING CAPACITY Any given environment can only support so many organisms Organisms compete for abiotic factors (shelter, food, water) If a population reaches its max, organisms will: Die Move Adapt

NICHES A niche is the role an organism plays in an ecosystem Two organisms CANNOT occupy the same niche If they did, they would compete for resources One of them would either: Die Move Adapt

HOMEOSTASIS Remember that organisms maintain homeostasis (a stable internal environment) so do ecosystems. Homeo = Same, Stasis = State of activity The biotic factors of an ecosystem rely on the abiotic factors such as temperature, water, nutrients If there are too much or too little of certain abiotic factors the biotic factors may die

HOMEOSTASIS DISRUPTION Fire Tornado Volcano Hurricanes Humans Tsunami Invasive Species

HOMEOSTASIS DISRUPTION In the food web; what would happen to the ecosystem if foxes were no longer there? How would the food web change if there was a drought? ØThe completeness of an ecosystem determines it’s health. ØBiodiversity describes the variety of species found in ecosystems ØA very diverse ecosystem means a healthy one!

NATURAL SELECTION AND ADAPTATION After a disruption organisms may die, move or adapt to the changes. Within a population there are many genetic variations. Just look around the room at the genetic variations of hair color or eye color within our population Some variations come from genetic mutations. A mutation is an inheritable change of genetic material and can be beneficial, neutral, or bad. An example of how variations leads to natural selection is found within the ground finch population of the Galapagos Islands. Normally the bird feeds on small seeds, but during the 1970’s there was a drought and only large seeds were available. Larger birds within the population were able to eat the seeds, and the smaller birds died off

NATURAL SELECTION & ADAPTATIONS CONT. Natural Selection- Through deaths within a population the “undesirable” traits are removed, leaving organisms with a trait that helps them survive their new environment. The surviving members adapt, or change, to their new surroundings, or they have specific genes that help them survive. Adaptations are characteristics that help an organism to survive under certain environmental conditions Adaptations can be behavioral, morphological (the form & structure ) or physiological (outward appearance) The surviving members of a population pass their genetic material onto offspring, producing a new generation that can survive