Introduction to Ecology

Vocabulary Taxonomy Biodiversity Six- kingdoms Dichotomous key Classification of animals Food web Biome Ecosystem

Ecology

What is Ecology The study of how organisms interact with their environment All organisms must interact with both living and nonliving things that surround them

Levels of Organization To add to our list of the levels of organization: Cells  Tissues Organs  Organ Systems  Organisms  Population  Community  Ecosystem  Biosphere

Levels of Organization Ecologists tend to label groups of organisms. Let’s look at a familiar setting for example: Your house is part of a town, this is part of a state, which is part of a country, which is part of a continent.

Levels of Organization Cont. No individual organism lives completely on its own. It may live with other individuals of the same species to form a population. Several populations living together make up a community. Several communities in a given area make up a biome.

Organization Cont. Collectively, all the biomes of the planet earth make up the biosphere. Again, the most basic level of ecological organization is the individual/species. A group of individuals of the same species make up a population. A community is all the populations of living organisms in an area.

Levels of organization

Organization Cont. The boundary of a community is determined by the distribution of its members. The boundary of one community is not necessarily the boundary of another community. We say these communities overlap.

Organization Cont. A biome is a large geographical area with a similar climate.

Biosphere The biosphere is the region on Earth where all life exists.

The environment Made up of all the living and nonliving things that surround an organism. Vocabulary: Abiotic Factors Biotic Factors

Two parts of an Ecosystem Biotic and Abiotic factors that are or were alive/living in an ecosystem. Examples: animals, plants, insects, bacteria, fungi, and dead organisms.

Abiotic Factors in an environment that are not or never were alive. Examples: rock island, gases, water, sun, minerals and temperature.

Environment vs Habitat Many species can survive in more than one environment. But each species has its “home” or habitat. Fish may be able to live in fish tanks, but would rather live in the wild

Habitat and Niche Each organism confronts the challenge of survival in a different way. The niche an organism occupies is the sum of all the ways it utilizes the resources of its environment. Part of this role may be played as the predator and part may be played as the prey.

Niche Example: Snakes eat mice and other birds and rodents but snakes are also eaten by birds of prey and mice eat grasshoppers and other insects.

Niche A niche may be described in terms of space utilization, food consumption, temperature range and mating requirements. An organism’s niche would also take into account its behavior. You can think of an organism’s niche as its job/role in the environment.

Niche A beaver is an ecosystem engineer. It cuts down trees and dams up a river which will flood the forest with a pond. Eventually the trees will dies, new species of plants and wildlife will arrive to take advantage of the new conditions. Eventually, this forest will become a meadow. The beaver’s NICHE is the role it plays in shaping the environment. But… it is also a main prey species for predators.

Habitat Niche is not synonymous with habitat. Habitat is a place, niche is a pattern of living. Habitat is the address and niche is the job or occupation. If two organisms have the same habitat and similar niches, they will compete with each other over the available resources. (food- water -shelter)

Habitat Competition is the struggle between two organisms within their habitat. If a species can avoid competing they may co-exist. But if they compete, one will eventually drive the other out of the habitat, unless they have slightly different niches. Example: times of activity

Different Niches to avoid competiton: Nocturnal – active at night Diurnal - active during the day Crepuscular – active at dawn and dusk

Different Niches to avoid competiton: cont… Migration – moving from one area to another to use resources Hibernation – reducing activity severely for a period of time.

Basic Concept of Ecology The fundamental idea behind the study of ecology is that all organisms are interdependent. They interact with one another and the physical environment.

Habitat A place where an organism lives or can be found.

Ecosystem An interacting system that consists of groups of organisms and their non-living environment with in a boundary.

Oligotrophic Lake: Nutrient poor, water is clear, oxygen rich; little productivity by algae, relatively deep with little surface area.

Eutrophic lake: nutrient rich, lots of algal productivity so it’s oxygen poor at times, water is murkier  often a result of input of agricultural fertilizers

Rivers and Streams: Organisms need adaptations so that they are not swept away by moving water; heavily affected by man changing the course of flow (E.g. dams and channel-straightening) and by using rivers to dispose of waste.

Wetlands: includes marshes, bogs, swamps, seasonal ponds Wetlands: includes marshes, bogs, swamps, seasonal ponds. Among richest biomes with respect to biodiversity and productivity. Very few now exist as they are thought of often as wastelands.

Estuary: Place where freshwater stream or river merges with the ocean Estuary: Place where freshwater stream or river merges with the ocean. Highly productive biome; important for fisheries and feeding places for water fowl. Often heavily polluted from river input so many fisheries are now lost.

Intertidal Zone: Alternately submerged and exposed by daily cycle of tides. Often polluted by oil that decreases biodiversity.

Coral Reefs: occur in neritic zones of warm, tropical water, dominated by cnidarians (corals); very productive, protect land from storms; most are now dying from rise in global temperatures

Deep-sea vent: Occurs in benthic zone; diverse, unusual organisms; energy comes not from light but from chemicals released from the magma.

Tropical Forest: Vertical stratification with trees in canopy blocking light to bottom strata. Many trees covered by epiphytes (plants that grow on other plants).

Example of Tropical, Dry Forest

Desert: Sparse rainfall (< 30 cm per year), plants and animals adapted for water storage and conservation. Can be either very, very hot, or very cold (e.g. Antarctica)

Chaparral: Dense, spiny, evergreen shrubs, mild rainy winters; long, hot, dry summers. Periodic fires, some plants require fire for seeds to germinate.

Temperate Grassland: Marked by seasonal drought and fires, and grazing by large animals. Rich habitat for agriculture, very little prairie exists in US today.

Temperate Deciduous Forest: Mid-latitudes with moderate amounts of moisture, distinct vertical strata: trees, understory shrubs, herbaceous sub-stratum. Loss of leaves in cold, many animals hibernate or migrate then. Original forests lost from North America by logging and clearing.

Coniferous forest: Largest terrestial biome on earth, old growth forests rapidly disappearing, usually receives lots of moisture as rain or snow.

Tundra: Permafrost (Permanent frozen ground), bitter cold, high winds and thus no trees. Has 20% of land surface on earth.

Climate Definition? The overriding factor that determines the general nature of an ecosystem. If the climate is always hot and dry, the soil will be sandy. The plants, animals and other life will be specially adapted for survival in a desert.

Climate cont. If the climate is hot and moist, then there will be many trees, characteristic of a Rainforest. Some animals and insects will be adapted for living in trees. They are called arboreal and include monkeys and spiders.

What do organisms need to survive? Basic requirements for survival include: Food Water Shelter

Competition An important aspect of the struggle for survival involves competition for limited resources Food Water Shelter Sunlight

Limiting Factors Limiting factors are factors that affect the population size of a species in a specific environment. They can be abiotic or biotic.

Predator – Prey relationship Predators are a biotic limiting factor. They control population size by feeding on prey. There is a delicate balance that needs to be maintained.

Carrying Capacity When all the limiting factors are considered together we can determine the maximum number of organisms that can survive in an area.

Key Idea All organisms have the ability to produce populations of unlimited size But their environment keeps their numbers in check.

Categories of Populations Populations are labeled by the function they serve in the ecosystem Producers Consumers Decomposers

Energy Flow Through an Ecosystem Food Chains, Food Webs, Energy Pyramids

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2 Begins with the SUN Photosynthesis 6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

Organisms that can make glucose during photosynthesis are called PRODUCERS.

Producers use most of the energy they make for themselves.

The energy that is not used by producers can be passed on to organisms that cannot make their own energy.

Organisms that cannot make their own energy are called CONSUMERS.

Consumers that eat producers to get energy: Are first order or primary consumers Are herbivores (plant-eaters)

A consumer that eats another consumer for energy: Is called a secondary or second order consumer May be a carnivore or a herbivore May be a predator May be a scavenger

A consumer that eats a consumer that already ate a consumer: Is called a third order or tertiary consumer May be a carnivore or a herbivore May be a predator May be a scavenger

Consumers that eat producers & other consumers Are called omnivores Omnivores eat plants and animals

Consumers that hunt & kill other consumers are called predators Consumers that hunt & kill other consumers are called predators. They animals that are hunted & killed are called prey.

Consumers that eat other consumers that have already died are called scavengers.

The transfer of energy from sun to producer to primary consumer to secondary consumer to tertiary consumer can be shown in a FOOD CHAIN.

Another way of showing the transfer of energy in an ecosystem is the ENERGY PYRAMID.

Energy pyramids show That the amount of available energy decreases down the food chain It takes a large number of producers to support a small number of primary consumers It takes a large number of primary consumers to support a small number of secondary consumers

Food Webs: Are interconnected food chains They show the feeding relationships in an ecosystem

So what is a Food Chain? A food chain shows a one way flow of energy in an ecosystem It may not be the only way energy flows in the ecosystem

Food Webs When all of the food chains of an ecosystem are considered we can draw up a food web It shows all of the possible paths that energy can take in an ecosystem It also shows how organisms are dependant on each other in the ecosystem

Food Web poster At least A3 poster Choose an ecosystem Explain the ecosystem Describe the ecosystem Have pictures of the animals DUE: 22nd JANUARY