Ecology The Biosphere Ecosystems and Communities Biosphere Human Interactions

Levels of Organization Individual organism – first level of organization Species – group of organisms that can breed and produce fertile offspring Population – members of the same species that live in the same area Community – different populations living in a defined area Ecosystem – all organisms living in a particular place along with the nonliving environment Biome – a group of ecosystems with the same climate and similar dominant communities Biosphere – the Earth

Levels of Organization

Energy Flow Sunlight is the main energy source for life on Earth Autotrophs/Producers – organisms that use energy from sunlight or chemicals to produce food Photosynthesis – process of using light energy to create bonds in glucose Chemosynthesis – process of using chemicals to produce carbohydrates

Energy Flow

Heterotrophs/Consumers – organisms that rely on other organisms for their energy and food supply Herbivores – organisms that obtain energy by eating only plants Carnivores – organisms that obtain energy from eating only animals Omnivores – organisms that obtain energy from eating plants and animals Detritivores – organisms that obtain energy from eating plant and animal remains and other dead matter Decomposers – organisms that obtain energy from breaking down organic matter

Feeding Relationships Food chain – a series of steps in which organisms transfer energy be eating and being eaten Food web – a network of complex interactions among feeding relationships between various organisms in an ecosystem Trophic level – each step in a food chain or food web

Feeding Relationships Predation – a relationship in which one species eats another species Camouflage – the colors or patterns on animals that help them hide in their surroundings

Feeding Relationships Symbiosis – a relationship in which two different species live in close association Parasitism – a symbiotic relationship in which one organism feeds off another organisms Host – an organism that is food for a parasite

Feeding Relationships Mutualism – a symbiotic relationship in which both organisms benefit Commensalism – a symbiotic relationship in which one organism benefits and the other is not affected

Feeding Relationships

Ecological Pyramids Energy pyramid – energy stored in on level is passed on to the next; only about 10 percent of the energy available within one tropic level is tranfered to organisms at the next trophic level Biomass pyramid – total amount living tissue within a given trophic level Number pyramid – number of individual organisms at each trophic level

Ecological Pyramids

The Water Cycle

Evaporation – the process by which water changes from liquid form to an atmospheric gas Transpiration – the process by which water evaporates from the leaves of plants Precipitation – water falling from the atmosphere in the form of rain or snow Condensation – the process by which water changes from atmospheric gas to liquid form Run-off – water moving along the surface of the Earth Seepage – water being absorbed by the soil Root uptake – water being absorbed by plants

The Carbon Cycle

Photosynthesis – process of converting CO 2 into glucose Respiration – process of converting glucose into CO 2 Decomposition/Deposition – process of returning carbon compounds to soil Volcanic activity – puts CO 2 into atmosphere from interior of Earth

The Nitrogen Cycle

Nitrogen fixation – bacteria converting nitrogen gas from the atmosphere into ammonia Denitrification – soil bacteria convert nitrates into nitrogen gas Ammonium – a nitrogen-containing compound used to cycle nitrogen into an ecosystem Nitrate – a nitrogen-containing compound used directly by plants

Climate Climate – the average, year-after-year conditions of temperature and precipitation in a particular region Weather – day-to-day condition of Earth’s atmosphere at a particular time and place The Greenhouse Effect – Carbon dioxide, methane, water vapor, and a few other atmospheric gases trap heat energy and maintain Earth’s temperature range.

Climate As a result of the differences in latitude and angle of heating, Earth has three main climate zones, polar, temperate and tropical.

Heat Transport Unequal heating of the Earth drives wind currents. Warm air currents rise, while cold air currents sink. Also, unequal heating causes ocean currents. Warm ocean currents rise, while cold ocean currents sink. Landmasses affect the movement of wind and ocean currents.

Heat Transfer

Biomes Terrestrial – having to do with the Earth Tropical forest – a terrestrial biome with many trees and organisms Savanna – a terrestrial biome with grasses and grazing animals Desert – a very dry terrestrial biome Chaparral – a terrestrial biome with many shrubs

Biome Temperate grassland – a terrestrial biome with fertile soil and tall grasses Temperate deciduous forest – a terrestrial biome with wet forests that change activity during the winter Coniferous forest – a dry, cold terrestrial biome with cone-bearing trees Tundra – a cold, dry terrestrial biome with shrubs and small trees Permafrost – permanently frozen soil

Aquatic Ecosystems Freshwater wetlands: water covers the soil or is present at or near the surface of the soil for part of the year. Examples: bogs, marshes, and swamps. Estuaries: formed where rivers meet the seas. Detritus: tiny pieces of organic material Salt marshes (temperate-zone) and mangrove swamps (tropical-zone)

Aquatic Ecosystems

Photic zone – well-lit upper layer Aphotic zone – permanently dark Intertidal zone – submerged in water and exposed to atmosphere Coastal ocean – low tide mark to the end of continental shelf Coral reefs – named for coral animals whose hard, calcium carbonate skeleton make up their structure

Aquatic Ecosystems Determined by the depth, flow, temperature and chemistry of the overlying water. Freshwater: Flowing water and standing water –Flowing water: rivers, streams, creeks, and brooks that flow over land –Standing water: lakes and ponds containing free-floating organisms (plankton)

Populations Population density – the number of individuals in a population in a particular area Sample – a part that represents an entire population Stability –the ability of a community to resist change Niche – the role an organism plays in the community

Populations Growth rate – the amount by which a population’s size changes in a given time Carrying capacity – the largest density an ecosystem can support for a particular population Density-dependent factor – a factor related to the density of a population that affects population size Density-independent factor – a factor that affects population size, but does not depend on the population density

Populations Competition – when organisms try to use the same resources Immigrate – to move into a population Emigrate – to leave a population Boom-bust cycle – a period in which the densities of populations increase or decrease at the same time

Populations Uniform – when a population spreads out evenly through an ecosystem Clumped – when a population spreads out in small groups through an ecosystem Random – when a population has no order as to how it is distribution through an ecosystem

Ecological Succession Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community. Pioneer species – first species to populate the area.

Ecological Succession

Human Impact Most populations eventually reach carrying capacity in their ecosystems. However, humans do not follow this pattern. When food or space becomes limited, humans find other resources to meet their needs. Scientists do not know the carrying capacity for humans. Currently, the population of the world is 6 billion. To meet their needs, humans at times harm or damage other organisms in their ecosystems.

Human Impact As humans go through their daily lives, they produce a large amount of trash and waste. Waste products are often disposed of in certain areas that were once habitats. Humans do not use some of these areas. However, they litter the land and water around them. This trash can harm or kill other organisms.

Human Impact Pollution – anything added to the environment that is harmful to living things Chemical runoff – the chemical waste produced on land that enters water sources Eutrophication – a process in which chemical runoff causes algae growth that chokes out other organisms in a water ecosystem

Human Impact Acid rain – rain that is caused by pollution and is harmful to organisms because it is acidic

Human Impact Greenhouse effect – the warming of the atmosphere because of trapped heat energy from the sun Ozone – a form of oxygen Solar energy enters the atmosphere. However, instead of reflecting back into space, greenhouse gases trap the energy in the atmosphere. This causes overall global warming.

Human Impact Land development – the changes people make to natural land so it becomes land for farming or living space Deforestation – the removal of forest ecosystems for land development

Human Impact Introduced species – a species taken from its natural ecosystem and placed in another ecosystem Examples: Kudzu, snakehead fish

Human Impact Conservation biology – the science of using ecological information to help reduce damage to the environment Landfill – an area where trash is collected and stored Recycling – using waste products to create new products Emission – a chemical waste given off as has

Human Impact Reserve – a protected area that cannot bu used for building or growth Landscape ecology – using ecological information to help balance human and environmental needs Protecting ecosystems helps protect species that live in them. Hunting seasons are times when certain animals can be hunted or fished.

Human Impact Endangered species have only a small number of individuals. Most countries have laws that protect the species on the endangered species list. Recovery plan – a plan using scientific knowledge to help bring endangered species back from possible extinction Biodiversity – total of all life on Earth

Human Impact Geology – the study of the nonliving parts of the Earth Biogeology – the study of the interaction between living and nonliving parts of the environment Engineering – the use of math and science to create methods and machines to help solve problems or make life better Engineer – person who works in engineering

Human Impact Technology – any device, machine, or method designed to solve a human problem or question Medical technology – any technology designed to solve a medical problem Patents – a government notice of ownership for a piece of technology Scientific journal – a scientific magazine The goal of scientists is to understand the natural world and solve problems to make life better.