Ecology And Conservation

Simpson Index Of Biodiversity
One method of measuring biodiversity
Abiotic Factors That Affect Distribution Of Plants
Temperature and water, light, soil pH, salinity, and mineral nutrients
Temperature And Water On Plant Distribution
If temperatures are hot there is most likely less water.Plant species more numerous in moist areas
Light On Plant Distribution
If plants have small leaves they aren't adapted to catch light and need it almost constantly
Soil pH On Plant Distribution
Different plants thrive at different pH levels
Salinity On Plant Distribution
Salty environments have certain plant types
Mineral Nutrients On Plant Distribution
Soil building up for hundreds of years has mineral nutrients that can support large trees. Some mineral nutrients can only support shrubs, lichen, and mosses
Factors Affecting Distribution Of Animal Species
Temperature, water, breeding sites, food supply, and territory
Temperature On Animal Distribution
Only certain species are adapted for very high temperatures and only some for very low temperatures
Water On Animal Distribution
Many animals are specifically adapted to live in wetlands. Some need the water for their eggs, others rely on bodies of water for food
Breeding Sites On Animal Distribution
Animals have specific needs for breeding sites. Habitat destruction can interfere with their ability to reproduce
Food Supply On Animal Distribution
Many animals are adapted to feed on specific food and must live where that food supply is available. Other animals are more wide-ranging
Territory On Animal Distribution
Some animals live in specific areas. And some animals mark their territory
Quadrat Method
A square of a certain size. Organisms in it are counted and are used to determine the population size
Transect Technique
Commonly used for studying how the distribution of plants in an ecosystem is affected by abiotic factors
Niche Concept
An organism's particular role in an ecosystem. Includes where the organism lives, what and how it eats, and its interactions with other species
Spatial Habitat
The area inhabited by any particular organism
Feeding Activities
The feeding activities of an organism affect the ecosystem by keeping other populations in check
Interaction With Other Species
Include competition, herbivory, predation, parasitism, and mutualism. Organism may be in competition for food supply, may itself be the prey, may harbor parasites, etc
Competition Between Species
When two species rely on the same limited resource, one species will be better adapted than the other to benefit from the resource (Coyotes and red foxes)
A herbivore is a primary consumer feeding on a producer. The growth of the producer is critical to the well-being of the primary consumer (rabbits eat grass)
A predator is a consumer eating another consumer. One consumer is the predator and one is the prey. The number of prey affects the number of predators and vice versa (lynx and hare)
A parasite is an organism which lives on or in a host and depends on the host for food for at least part of its life cycle. Host is harmed by the parasite (Plasmodium causing malaria in humans)
Two species living together where both organisms benefit from the relationship (Lichen's relationship with algae and fungi)
Competitive Exclusion
States that no two species in a community can occupy the same niche (G. F. Gause lab experiment with Paramecium: P. aurelia and P. caudatum. Showed effects of interspecific competition between two closely related organisms)
Fundamental Niche
The potential mode of existence, given the adaptations of the species
Realized Niche
The actual mode of existence, which results from its adaptations and competition with other species
Relationship Between Fundamental And Realized Niche
Fundamental niche is the complete range of biological and physical conditions under which an organism can live and realized niche is when conditions have changed and a new and narrower niche is created (fox and coyote situation)
The total mass of organic matter. Organic matter consists of carbohydrates, lipids, and proteins. Matter usually contains water so it has to be dried to be measured. Expressed by: g m^-2yr^-1 (grams per meter squared per year)
Energy Flow Through The Ecosystem
As energy goes from producers to consumers it is lost dramatically throughout
Gross Production
The total amount of organic matter produced per unit area per unit time by a trophic level in an ecosystem
Net Production
Gross production less the material expended by the plants in respiration
Gross And Net Production
Both measured in kJ per squared meter per year
Calculating Gross And Net Production
Gross production - respiration = net production
Pyramids Of Biomass
Similar in shape to pyramids of energy. The higher trophic levels have low total biomass per unit area of ecosystem. Biomass is lost during respiration at each trophic level. When glucose is broken down for energy, it is converted into carbon dioxide gas and water
Difficulties Of Classifying Organisms Into Trophic Levels
For example an eagle is a tertiary consumer when eating rattlesnakes but a secondary consumer when eating rabbits. Omnivores are difficult to classify into one trophic level. For example bears eat plants, bugs, and other mammals
Ecological Succession
The change in abiotic and biotic factors in an ecosystem over time
Primary Succession
Begins when plants begin growing on a previously barren and lifeless area. First colonizers are usually lichens. As they die and decompose they form soil. Eventually there will be enough soil for other seeds to germinate
Secondary Succession
A new group of organisms takes over following a natural or artificial upheaval of the primary succession. Much faster than primary succession as soil is already present and there may be existing seeds and roots present.
Differences Between Primary And Secondary Succession
P: begins with no life S: follows a disturbance of the primary succession
P: no soil S: soil is present
P: new area e.g. volcanic island S: old area e.g. following a forest fire
P: lichen and mosses are first plants S: seeds and roots already present
P: biomass low S: biomass higher
P: low production S: higher production
Living Organisms Change The Abiotic Environment
Organic matter increases, soil gets deeper, soil erosion reduces, soil structure improves, and mineral recycling increases
Organic Matter Increases (Living Organisms Change The Abiotic Environment)
Soils contains a reservoir of organic matter or humus which is a result of the death and decay of many plants and animals. Humus quickly absorbs and releases water and is therefore an excellent medium for plant growth. It is lightly packed and allows oxygen to be available for plant roots
Soil Gets Deeper (Living Organisms Change The Abiotic Environment)
Leaf litter and decayed plants create organic matter which is now mixed with the sand of the dune thus creating a deep, well-draining soil on the mature dune. It is deep enough to support the tall trees which live there
Soil Erosion Reduces (Living Organisms Change The Abiotic Environment)
Throughout the story of the dune succession, you can see how plant roots stabilize first the sand and then the soil
Soil Structure Improves (Living Organisms Change The Abiotic Environment)
Sand does not hold moisture. Gradually, over hundreds of years, humus develops and slowly produces a structure which holds moisture and minerals and allows the aeration of plant roots
Mineral Recycling Increases (Living Organisms Change The Abiotic Environment)
Bacteria and fungus can be active in recycling nutrients in soil which has enough humus. Ecosystems create their own nutrients by recycling them from the plants and animals that live and die there
Anywhere that organisms live
Divisions of the biosphere. Occur because of global weather patterns and topography
Tundra Biome
High elevations, low temperatures, low precipitation
Coniferous Forest Biome
High elevations, cold temperatures, slightly more rainfall
Temperate Forest Biome
Lower elevations, temperatures are even warmer, more water is available
Desert Biome
Low elevations, warm temperatures, little precipitation
Tropical Forest Biome
Low elevations, warm temperature, very high moisture
Seven Major Biomes
Desert, Grassland, Shrubland, Temperate Deciduous Forest, Tropical Rainforest, Tundra, Coniferous Forest
Simpson Diversity Index
Formula: D=N(N-1)/sum of n9n-1)
D=diversity index
N=total number of organisms in the ecosystem
n=number of individuals of each species
Biological Diversity
Richness: the number of different organisms in a particular area
Evenness: how the quantity of each different organism compares with the other
Economic Reasons For Conservation Of Biodiversity
Attempts to farm on rainforest soils has not been successful. Most of the nutrients are locked up in the tissues of the plants and the soil left behind after logging is devoid of nutrients. Plant sources of medicines and chemicals are lost forever if species are extinct. As long as the rainforest exists, there is the possibility that local crop plants and farm animals could be improved with alleles from wild populations. Ecotourism could improve the local economy
Ecological Reasons For Conservation Of Biodiversity
Loss of one species could affect other species because many organisms in the ecosystem are interdependent. Diversity protects an ecosystem against invaders. If alien species are introduced, they will be competing with the existing species in the ecosystem. The more diverse the ecosystem is, the better able it is to withstand pressure from alien species. Disruption of the ecosystem can lead to soil erosion and flooding
Ethical Reasons For Conservation Of Biodiversity
The ethical solution to saving the rainforest is to include the local population in creative ways to conserve it. Many organizations are helping communities make a living from the rainforest while at the same time preserving it. We have an ethical responsibility to conserve the rainforest so that future generations have access to its beauty and wealth of organisms. Another ethical way to help is creating public awareness of the problem
Aesthetic Reasons For Conservation Of Biodiversity
Humans have the ability to visit natural areas in our biosphere that have been preserved. Ecotourism is a booming industry which is helping save parts of the rainforest. Rainforest has inspired many writers and artists
Arguments Against Conservation
Conservation measures may slow down the economic development of countries with tropical rainforests. Clearing these forests does provide some land for agriculture. Tropical rainforests can be reservoirs of pest species or species which transmit disease
Introduction Of Alien Species
Disrupts communities. They are often able to out-compete native species. It reduces biodiversity. Many native species can be forced out of an ecosystem by one invader. Example: Kudzu (introduced from Japan to the U.S. Was an ornamental plant but was also seen as a fast-growing plant which could solve the problem of soil erosion. Finally recognized as a pest weed.)
Deliberate Release Of An Alien Species
Kudzu: introduced from Japan to the U.S. Was an ornamental plant but was also seen as a fast-growing plant which could solve the problem of soil erosion. Finally recognized as a pest weed. Currently in the southern states and an annual sum of $500 million is lost through the effects of kudzu
Accidental Release Of An Alien Species
Zebra Mussels: Invaded North America possibly by European cargo ship which contained these mussels in its ballast water. They have spread allover the Great Lakes. Have had an enormous economic impact. They clog any pipe which transport surface waters thus affecting utility plants, factories, and water treatment plants. They are causing the water in Lake Michigan to be really clear and enables more light to penetrate the water. More light causes increased growth of aquatic weeds. Weeds provide a good place for fish to hide and spawn
An Alien Species Under Control
Prickly Pear: the cactus was introduced to Australia by Europeans and Americans. It was spreading at a rate of 400,000hectares per year. A moth called Cactoblastic cactorum feeds on the cactus. They were immediately brought to Australia and there is now a balance between the two populations
Impact Of Alien Species On Ecosystems
Alien introductions can lead to interspecific competition, predation, and extinction of a native species. All cause a reduction in diversity
Interspecific Competition
A species which invades an ecosystem can out-compete the native species. Example: Grey squirrel dominating the red squirrel
Predation Of Alien Species
A species which invades an ecosystem can eat another species. Example: ocean fish being free to travel to freshwater areas (lamprey)
Species Extinction
A species which invades an ecosystem can out-compete the native species and cause its extinction. Example: Nile perch in Lake Victoria. Lake Victoria is shared by the African countries Kenya, Tanzania, and Uganda. In the 1950s fish population declined due to over fishing. The Nile perch was introduced to increase fish population. 80% of the fish population was originally cichlids. By 1970 the cichlid population had dropped to 1%. Of 400 species of cichlids in Lake Victoria, 200 are now extinct
Biological Control
The idea of using a natural predator to control an unwanted or invasive species
Purple Loosestrife
An aggressive plant which has invaded the US and Canada. It displaces native wetland plants and became the the dominant plant in wetland areas. Serious threat to biodiversity because a single plant that produces two million seeds each season are dispersed along rivers and waterways. Beetles can be control agents. The goal of biological control is to reduce the numbers of purple loosestrife in the environment
Red Fire Ants
Are an imported pest insect in the US. They are common in the southern states and heading north. They compete with native ants and dominate. A phorid fly is a natural predator of the fire ant
A process by which chemical substances become more concentrated at each trophic level. When chemicals are taken up by plants they may not be harmed by it. However, when consumers eat the plants it takes in a larger amount of chemicals. If a secondary consumer eats the primary consumer the amount of chemicals taken in are magnified even more. Chemicals which are biomagnified in this manner are fat soluble. After ingestion, they are stored in the fatty tissue of the secondary consumer
Causes Of Biomagnification
Chemicals are used to kill pests. One of these pesticides was DDT. It was not known that DDT did not break down and would persist for decades in the environment. DDT was commonly sprayed on plants and eventually entered water supplies. It was absorbed by microscopic organisms then eaten by small fish then larger fish then the DDT built up in the fatty tissue of the larger fish then birds ate the larger fish
Consequences Of Biomagnification
DDT caused a decline in the number of birds. Eggs of these birds were easily cracked. DDT was building up in the tissue of the birds and interfering with calcium for the shell to be hard
Non-Lethal Skin Cancer (Effects Of Ultraviolet Radiation)
Basal and squamous cell carcinoma are common forms of skin cancer which are not lethal. Scientists have been collecting data on these forms of skin cancer and have found that a decrease of 1% of stratospheric ozone increases these cancers by 2%
Lethal Skin Cancer (Effects Of Ultraviolet Radiation)
Malignant melanoma is a form of skin cancer which is lethal in 15-20% of cases. Early detection is the key factor in recovery from this type of skin cancer
Mutation Of DNA
UV radiation causes changes in the structure of DNA
Reddening of the skin due to UV radiation is caused by enlargement of small blood vessels. Some cells of the epidermis die and peel off
A clouding of the lens of the eye leading to loss of vision. Long-term exposure to UV rays is a risk factor for cataracts
Reduced Biological Productivity
UV radiation can damage and kill plant cells. Affects the ability of plants to photosynthesize. UV can also damage the DNA of cells involved in growth. This can reduce the biomass of the plant and decrease net productivity. Phytoplankton or floating microscopic plants are especially susceptible
The Ozone Layer
Absorbs UV radiation. 20 kilometers thick. The formation of ozone (O3) occurs in the stratosphere when an oxygen molecule (O2) breaks apart and reacts with another oxygen molecule to form ozone. Ozone is constantly being formed, broken down, and re-formed
Chlorofluorocarbons. CFCs are the cause of ozone depletion. The Montreal Protocol was adopted to phase out CFCs by reducing use of refrigerator coolants, propellants for aerosols, and material used to make foam packaging. In the stratosphere CFCs break down to release chloride ions. The chloride ions react with ozone molecules to produce C10 and oxygen. The C10 joins with an oxygen atom to form more oxygen gas and release a chloride ion. This leaves a free chloride ion to destroy another ozone molecule
Indicator Species
Species that are very sensitive to environmental change. Lichen is a common indicator of air quality. Lichens are not usually found on trees in a city because of pollution. Since lichens also retain metal in their tissues, they can show the presence of lead or mercury in the air. Macroinvertebrates found in water determine water quality
Biotic Index
When you perform a river or stream study, you count the number of macroinvertebrates collected in each sample and record the data on a stream study form. The number of organisms of each group is multiplied by a factor which is determined by how sensitive the organism is to pollution. The presence of sensitive organisms is multiplied by a higher number. The more sensitive organisms you have in the sample, the higher the quality of the water in the river or stream. The total number is called the biotic index
Factors Contributing To Extinction
The Carolina parakeet was a bright yellow and orange bird that went extinct due to loss of habitat, human fashion, and captivity
Features Of Nature Preserves Which Promote Biodiversity
Three biogeographic features are taken into account when nature reserves are planned: the size of the reserve, the amount of edge, and the use of corridors
Determinations In Size (Features Of Nature Preserves Which Promote Biodiversity)
Larger sites are favored over small sites. Small sites will have low population numbers. With lower numbers there is greater risk for extinction. Unexpected factors like fire or disease could occur. Small habitats also have more edge area overall than a large site. They are more at risk for predation and competition by invasive species
Edge Effect (Features Of Nature Preserves Which Promote Biodiversity)
Example: the forest edge is the boundary between the forest and the disturbed area around it. At the edge of there forest there is more sunlight, more wind, and less moisture than the center of the forest. Organisms that live in the edge have more competition from other species
Corridors (Features Of Nature Preserves Which Promote Biodiversity)
Connect otherwise isolated habitats. Wildlife can travel between habitats in these corridors. Can be as simple as a tunnel under a busy road or as extensive as the following example. To connect China's giant pandas with more habitats, the World Wide Fund for Nature (WWF) working with the Chinese government has established corridors between 40 isolated panda populations. Some problems with corridors are: narrow corridors can expose animals to predators, invasive species can enter the habitat using a corridor, corridors which affect human populations can cause controversy
Management Of Conservation Areas
Restoration, recovery of threatened species, removal of introduced species, legal protection against development or pollution, and funding and prioritizing.
Restoration (Management Of Conservation Areas)
Attempts to return the land to its natural state
Recovery Of Threatened Species (Management Of Conservation Areas)
Usually helped when their habitat is restored
Removal Of Introduced Species (Management Of Conservation Areas)
Most of the exotic species which are introduced die out because they do not have adaptations to the local ecosystem. However they can be devastating and need managed
Legal Protection Against Development Or Pollution (Management Of Conservation Areas)
Nature reserves are protected against activities which might harm the native animals and plants. Such activities might include extraction of minerals, development of recreational facilities, hunting of animals or over-use by the public. Active management measures would include posting of signs and using security personnel to assure protection o the nature reserve from harmful human activities
Funding And Prioritizing (Management Of Conservation Areas)
Increasing public awareness of reserves helps gather funds to support the reserve. Management of nature reserves requires a balance between the good of the ecosystem, maintenance of diversity, and the costs involved