Introduction to Ecology Ch. 13

Ecology ….the study of the interactions between organisms and the living and nonliving components of their environment. Greek: Oikos = house

A Key Theme In Ecology Interconnectedness or Interdependence: All 5 levels of Ecological Organization , influence by biotic and abiotic factors.

Levels of Ecological Organization Organisms-> Populations-> Community->Ecosystem-> Biome

Levels of Ecological Organization Definitions: Populations: A group of indiciduals of one species living in one area. Community: All organisms living in one area. Ecosystems: All the organisms in a given area as well as the abiotic (non living) factors\ Biosphere- The global ecosystem.

How do we Research? Lab: pg.401 Observation Experimentation Modeling: taking past data to predict how it will effect the ecological organisms in question. Improving Predictions Weather observation techniques have improved and there have been technological advancements in predicting the weather in recent times. On average, a five-day weather forecast of today is as reliable as a two-day weather forecast 20 years ago. Despite this major scientific and technical progress, many challenges remain regarding long-term weather predictability.

Biotic and Abiotic Factors Biotic: all living things Abiotic: temperature, humidity, pH, salinity, oxygen concentration, sunlight, nitrogen, and precipitation.

Changes in the Environment

Changing one factor in an ecosystem can effect Biodiversity. Biodiversity: The variety of life in an ecosystem. Keystone Species: A single species that effects the entire ecosystem The carnivorous starfish Pisaster ochracceus is a keystone species in the intertidal zones of the Pacific northwest Paine (1969) originally defined a keystone predator as a species that feeds preferentially on the dominant competitor among its prey species, such that the keystone predator’s feeding prevents the dominant prey from excluding other species, and therefore maintains a higher species diversity in the system than in the keystone’s absence

Energy Transfer Producers: Autotrophs (photo and chemo) Gross primary productivity, biomass, and net primary productivity Gross energy: Amount of energy produced total, Net energy: amount of energy that can be used by others.

Consumers Heterotrophs: Herbivores, carnivores, omnivores, detritivores, saprophytes, and decomposers.

Energy and the rule of 10

Food Web

What type of consumer are you? Generalist: have a varied diet Specialists: only eat one specific organism or a few types organisms. Include: Herbivores:Plants Carnivores: Animals Ominivores: Plants and Animals Detritovores: Eat detritus, dead organics Decomposers: Like fungi break down organic matter into simple compounds.

How does matter Cycle? Water cycle Oxygen Cycle Carbon Cycle Nitrogen Cycle Phosphorous Cycle

Ecosystem Recycling

Today’s Environment Exploding Human Population ….increasing demand for energy, food, and space. Population: A group of individuals of one species living in one area who interbreed and interact. Human Population Graphs

Sixth Mass Extinction ….Loss of habitat, pollution, over hunting and fishing. Oil Rig Disasters…oops!

The Great Pacific Garbage Patch                      The Great Pacific Garbage Patch The size of Texas

Thinning Ozone Layer

Clamatic Changes Global Warming and the Greenhouse Effect.

Enduring Changes Performance Vs. Environmental Changes

Responding to Changes Acclimation

Control of Internal Conditions ….Conformers and Regulators

Escape ….Dormancy and Migration

The Niche Species’ Role: environmental conditions needed resources number of offspring time of reproduction all environmental interactions

Fundamental Niche ….range of conditions/resources a species can potentially tolerate and use. Realized Niche ….range of conditions/resources a species actually use.

Generalists Vs. Specialists

Measuring Populations Growth Rate: birth, death, emigration, immigration Demographers assume immigration and emigration are zero when calculating growth rate.

The Exponential model

The Logistic Model

Population Regulation Density Independent Factors ….weather, floods, and fires have the same effect regardless of population size.

Density Dependent Factors ….include resource limitations and are triggered by increasing population density.

Perils of Small Populations: Loss of Genetic Variation

Species Interactions Ant Farmers Of The Amazon

Types of Symbiosis Predation

Parasitism

Competition ….Competitive Exclusion

Character Displacement and Resource Partitioning ….Finding ways for species with similar niches to live together.

Mutualism ….Both species benefit. Commensalism ….One species benefits and the other is not affected.

Succession Primary Succession

Secondary Succession

Terrestrial Ecosystems

Aquatic Ecosystems Oceans

Aquatic: Fresh Water Eutrophic Lakes and Oligotrophic Lakes Ponds, rivers, and streams.

How Technology can help. Dr. Thomas’ Article On “Green Clean”