CHAPTER 2: PRINCIPLES OF ECOLOGY 11/29/16
Ecology The scientific discipline in which the relationship among living organisms and their interactions with their environments are studied.
Scientist who study ecology are called Ecologists. Ecologist travel the world and study organisms in their environment and compile research on how they affect each other and how their environment affects the organisms.
There are many branches of ecology. Some include: Habitat ecology Community ecology Population ecology Evolutionary ecology Taxonomic ecology Human ecology Applied ecology Ecosystem dynamics And there are many more!
The Biosphere
The Biosphere is the portion of earth that supports life. The term bio means Life.
The biosphere forms a thin layer around the earth. It extends several kilometers above earths surface into the atmosphere and extends several kilometers below the ocean s surface to the deep ocean vents.
It includes landmasses, bodies of freshwater & saltwater, and locations below the earths surface that support life.
From Rainforest to deserts to coral reefs and cities, diverse organisms populate diverse locations.
The biospheres diverse environments bring the most diverse organisms that are able to survive in their particular environment. Ecologists study these environments and their organisms, their adaptations, and the factors in their environments.
Biotic factors The living factors in an organisms environment are called Biotic factors.
The biotic factors include all of the organisms that live in the forest. Whether it be on land or in water. Ranging from the algae to the birds that migrate through the area.
Abiotic Factors The nonliving factors in an organisms environment are called Abiotic factors.
These factors include temperature, air or water currents, sunlight, soil type, rainfall, or available nutrients.
Organisms depend on abiotic factors for survival. Abiotic factors important to a plant are rainfall, amount of sunlight, the type of soil its planted in, the temperature, and the nutrients available in the soil.
Yesterday we talked about what makes up the biosphere. Today we will be disusing how the Biosphere is way to large and complex to study as a whole. So scientist have adopted to study the different levels of organization within the biosphere to get an understanding of the biosphere as a whole.
Levels of Organization
Organism Population Biological Community Ecosystem Biome Biosphere The Levels of organization increase in complexity as the numbers and interactions between organisms increase.
To gain a better understanding of the levels of organization. We are going to use this ocean as an Example.
Organism The lowest level of organization (the individual organism itself).
Population Individual organisms of a single species that share the same geographical location at that same time.
Biological Community A group of interacting populations that occupy the same geographical location at the same time.
Ecosystem A biological community and all of the abiotic factors that affect it.
Biome A large group of ecosystems that share the same climate and have similar types of communities.
Biosphere All of the biomes on earth combined.
Ecosystem Interactions
A Habitat is an area where an organism lives.
A niche is the role or position that an organism has in its environment. How it meets its needs for food, shelter, and reproduction.
Community interactions
Organisms that live together in a biological community are constantly interacting with each other. It is these interactions along with abiotic factors that shape their ecosystem.
These interactions can include competition for food, shelter, and potential mates. Even so, some organisms depend on each other for survival.
Competition Competition occurs when more than one organism uses the same resource at the same time. These resources may include food, water, space, and light. As strong organisms directly compete with weak organisms, only the strong survive and others die off.
Predation The act of one organism pursuing and consuming another organism for food. Organism that pursues another organism is called the predator and the organism that is pursued is called the prey.
Symbiotic Relationships The close relationship that exist when two or more species live together is called symbiosis. *There are three different types of symbiosis.
1. Mutualism A relationship between two or more organisms that live closely together and benefit from one another. Example: Bees and flowers.
2. Commensalism A relationship in which one organism benefits and the other is neither helped nor harmed in the process. Example: clown fish and sea anemones.
3. Parasitism symbiotic relationship in which one organism benefits at the expense of another organism. Example: flee or tick, bacteria, tapeworm, heartworm, etc.
Flow of Energy in an Ecosystem
Energy in an Ecosystem An autotroph is an organism that collects energy from sunlight or inorganic substances to produce food. Photosynthesizing organisms Also called primary producers
A heterotroph is an organism that gets its energy requirements by consuming other organisms. (Also called consumers) Heterotrophs that only eats plants are called Herbivores. Primary consumers
Heterotrophs that prey on other heterotrophs are called Carnivores. Secondary consumers.
Animals that mostly eat secondary consumers are called Tertiary consumers.
Organisms that eat both plants and animals are called omnivores.
Detritivores are organism that eat fragments of dead matter in an ecosystem, returning nutrients to the soil, air and water where the nutrients can be reused by organisms. Decomposers are similar to detritivores.
Decomposers are the primary method and tool to break down organic compounds and make nutrients available to producers to reuse. Without them none of this would happen and nutrients would not be recycled.
Models of Energy Flow
Food webs and food chains are used by ecologist to model energy flow through an ecosystem.
Each step of the food chain or food web is called a trophic level.
Autotrophs make up the first trophic level in all ecosystems and heterotrophs make up the remaining levels. Disregarding the first level, organisms at each level get their energy from organisms in the level before it.
A food chain is a simple model that shows how energy in an ecosystem flows Arrows represent one way energy flow which typically starts with producers to consumers.
Food webs are models that represent the many interconnected food chains and pathways in which energy flows through a group of organisms.
An ecology pyramid is a diagram that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level in an ecosystem.
Pyramid of Energy Each level represents the amount of energy that is available to that trophic level. With each step there is a loss of 90%.
Pyramid of Biomass Each level represents the amount of biomass consumed by the level above it. Amount of biomass is the total mass of living matter.
Pyramid of Numbers Each level represents the number of individual organisms consumed by the level above it.
1.What are producers and consumers in an ecosystem? 2.How does energy flow through an ecosystem? 3.What are food chains, food webs, and ecology pyramid models?
Cycling of Matter
The Water Cycle
All living organisms rely on freshwater for survival. Fresh water constitutes about 3% of all water on earth. Water available for living organisms is about 31% of all freshwater. The remaining 69% of all freshwater is frozen and found in ice caps and glaciers.
Scientist who study water are called Hydrologist.
Water is constantly being evaporated into the atmosphere from bodies of water, soil, and organisms. Water in the atmosphere is called water vapor.
Water vapor rises and begins to cool in the atmosphere. Clouds form when the cooling water vapor condenses into the droplets around dust particles in the atmosphere.
Water falls from the sky as precipitation in the form of rain, snow, sleet, or hail, transferring that water to the earths surface. Ground water and run off then flow into streams, rivers, lakes and oceans, where they will evaporate again and continue the cycle.
About 90% of water vapor evaporates from oceans, lakes, and rivers. 10% from surface of plants through a process known as transpiration.
Draw your own water cycle diagram and label all steps.