Ecology PowerPoint

Ecology and Conservation G.1 Ecology of Species Outline the factors that affect the distribution of plant species including temperature, water, light, soil pH, salinity and mineral nutrients Explain the factors that effect the distribution of animal species including temperature, water, breeding sites, food supply and territory

Investigation on Ecology What are the possible IV’s ? Will you have a range or 2 conditions? How will you control and monitor your IV? How will you measure your DV?, will you sample or count all organisms? What are the different techniques? Will you work in the field or model conditions in the lab? What is your sample size? Think about how data analysis affects your data collection and methodology.

How abiotic factors affect plant distribution Different species thrive under different conditions. Individuals within a population will vary somewhat and… Each population has a range of tolerance for any abiotic factor Within this range will be some optimum level and…. Outside the range few individuals will survive

The law of tolerance “ The existence, abundance and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species” ( Miller, Living in the Environment, p.104)

Light Solar energy powers almost all ecosystems Autotrophs need light In terrestrial systems light is usually NOT the limiting factor, although plants, trees may compete for light In aquatic systems light can only penetrate so far down: photic zone, water absorbs more red light. Light is also important in behavior- organisms can sense the relative amounts of day and night- photoperiod- affects breeding, migration, flowering

Water Organisms in aquatic environments must balance their internal osmolarity- this requires some homeostatic mechanism Terrestrial organisms need water, some plants have adaptations to low water (xerophytes) Animals also have adaptations to low water environments: camels, small rodents with very long Loops of Henle, etc.

Temperature Temperature affects metabolic reactions Some organisms cannot regulate their internal temperatures: ectotherms Endotherms can only regulate their internal temps so much and so cannot live in temp extremes Cells may rupture if below freezing Some organisms have adaptations to extreme heat: thermophiles, adaptations to cold, thick fat layer, fur Temp and water are 2 most important factors in climate climatograph

pH Organisms have optimal pH‘s which differ- ex. Coniferous forest like low pH, the plant Asperula likes alkaline soil where there is chalk or limestone Adaptations allow some organisms to live at extremes, other organisms are very sensitive- like phytoplankton

Salinity Similar to pH Organisms that can withstand high salt concentration are called halophiles

Minerals Plants need to obtain minerals from the soil Nitrogen, potassium and phosphorous are the most important

Breeding Sites Animals require certain conditions to breed If these are not available they may not breed successfully Insects may need water Wetlands are important sites for birds, destruction of these sites can drastically affect a population

Food supply Animals need a food supply, many animals have very specific requirements- ex Pandas will only eat bamboo, whales eat krill Other animals can adapt to different foods, generalist, like humans

Territory Some animals are territorial- they establish and defend discreet areas. They must be in their territory to eat or breed. Animals will fight to stay in the territory

Distribution patterns Clumped : some areas have higher density than others fish swimming in a group expend less energy. May decrease predation Territoriality will cause this pattern

Distribution patterns Uniform : organisms are spread out evenly Plants space out evenly to maximize light and water Animals may have uniform distribution as a result of aggressive interactions This pattern is less common in nature

Distribution patterns Random : an unpredictable pattern Happens when there is no strong attraction or or repulsion among individuals The location of one is not dependent on another Most common pattern

Niche The species way of life, functional role, where it lives, what it eats, what eats it, what abiotic factors it requires, how it reproduces, how it affects living and nonliving things in its environment. Niche is based on 3 main components: habitat , nutrition and relationships

Niche What describes a palm tree’s niche? An autotroph- provides food for the animals, humans Roots help maintain water table Provides shade for plants and animals Recycles nutrients Provides habitats for insects and birds Provides support for vines

Niche Some aspects of a species may overlap. The birds on the right inhabit the same tree but have different niches. Two species cannot occupy the same niche

Competitive exclusion This is the principle that states that 2 species cannot occupy the same niche If 2 species have the same niche and are in the same environment they will compete and one will win, the other will lose (be excluded)

Fundamental and realized niche Fundamental niche is the potential way an organism exists, given the total range of environmental conditions, due adaptations of the species. Realized niche is the ACTUAL way an organisms exists, which results from its adaptations and competitions with other species Realized niche is smaller than fundamental niche Biozone 284, 286,287,288, research ONE organism from page 285 for homework

Review What are 3 factors that affect distribution of plants? What are 3 things that affect distribution of animals? What is the precautionary principle? Define niche. What is the competitive exclusion principle? Compare fundamental and realized niche.

Ecology of Communities Interactions between species: All organisms are affected by interactions with other organisms. What are some ways organisms interact?

Competition If 2 different species are competing for the same resource this is called interspecific competition. The growth of one or both will be affected. Because of the competitive exclusion principle there are 2 possible fates when two species occupy the same niche: Either the less successful one will become extinct or will evolve enough to use different resources. The differentiation of niches is called resource partitioning.

Competition Intraspecific competition is when organisms of the same species compete. Two kinds: Adapted or programmed : instinctual social behavior to maintain hierarchy in the population Unadapted or incidental : due to scarce resource

Herbivory The consumption of an autotroph is herbivory Plants cannot move or defend themselves like animals but they do have some defenses: Spines, thorns, chemicals like strychnine, nicotine, bitter taste Animals also have adaptations such as sensors to locate food, mouthparts adapted to shredding tough plants or sucking nectar

Predation The interaction between species when one species kills and eats the other Predator-prey relationship Animals have adapted to protect themselves from predators in many ways: Camouflage, mechanical protection, chemical defenses

Symbiosis Two or more species live together in direct contact. Three types are: parasitism, commensalism and mutualism

Parasitism Interaction where one species lives on another, receiving nutrition from that organism,called the host. Parasites often do not kill their host but the relationship is harmful to the host Examples: tapeworms in humans, mistletoe and trees

Mutualism Both species benefit from the relationship Examples: clown fish and anemone, leguminous plants and N-fixing bacteria, honey bee and clover

Biomass Biomass is usually based on dry mass. To prepare specimens for dry mass you put it into a drying oven for about 14 hours. All the water should be gone by that point. For the most accurate data you include the entire plant and all the organisms- this is called the standing crop.

Alternate methods for measuring biomass Measure the biomass of the sample and extrapolate from that what the biomass of the population would be. Take samples of target species by cutting at soil level. Determine mean mass by multiplying by mean stem density

Alternate methods for measuring biomass Sample the area using a quadrat that is randomly selected Determine the mean height of the sample Multiply the mean height by stem density This gives an indirect measurement of biomass Some new methods using digital image analysis can also be used

Random sampling techniques Determine the area to be sampled Divide it into small areas or quadrats Use a random number table to determine which ones you will sample Throw your quadrat over your back- where it lands, is where you sample

Practical Ecology Quadrat: a frame that forms a known area. It may be subdivided into smaller areas. It can be used to measure: Percentage cover, density or frequency

Practical Ecology Frequency: The chance of finding a named organism within the sample area in a number of quadrats May be expressed as a percent of the total number of quadrats sampled

Frequency Throw the quadrat randomly in the sample area Record the presence or absence of a named organism within each quadrat Repeat for a number of throws Tabulate results

Percent Cover Use when it is difficult to determine individual organisms. Throw the quadrat randomly Determine the area that is covered by the organism Calculate percentage

Density Throw the quadrat randomly Count the number of organisms in the entire quadat or sample within the quadrat randomly (the technique is dependent on the size of the organism) Repeat and determine the mean and or total number based on area.

How many quadrats should you do? Each quadrat is like a replicate The more you do, the more likely you will have reliable results Time, size of the area, variation in distribution are factors that must be considered

Transect Line transect: String a line along the ground from two points. This is usually done where there is some gradation of an abiotic factor. Look for presence of target organism/s at some predetermined interval or sample continuously. Analyze to see if abiotic factor affects presence of organism

Transect Belt transect Same as line transect, except you are sampling some width rather than just a point. You can use a small quadrat Biozone 347-358

Review Discuss relationships between organisms: Predation, parasitism, mutualism, competition, herbivory Report on sampling method: describe technique, report on results, how would you analyze the data?,evaluate technique: errors, what type of organism is best suited to this method,

G.2 Measuring Production of an ecosystem Remember that organisms are grouped into trophic levels depending on their feeding relationships The trophic level that supports the ecosystem is the first, made up of primary producers. (photosynthetic, chemosynthetic). In order to measure the production of an ecosystem we look at how productive the producers are

Measuring Production of an ecosystem Only a very small part of the energy of the sun is converted into chemical energy in the plant. What percentage do you think this is? 1%

Measuring Production of an ecosystem Primary Production is the amount of light energy converted to chemical energy during a given unit of time. Gross primary production is the total amount of light E converted to chemical E per unit of time. (GPP)

Measuring Production of an ecosystem Net production is the GPP minus the energy used by the producers for respiration R. So NPP=GPP-R NPP is a more helpful number than GPP, why? In some cases NPP is as little as 25% of GPP- large trees have more respiration expenditures.

Measuring Production of an ecosystem Biomass is the energy of primary production per unit area per unit of time. (J/m2/yr) Biomass is expressed in terms of the dry mass of organic material.

Measuring Production of an ecosystem Calculations: page 304 and 305 in Biozone

Trophic Levels Organisms are classified into trophic levels according to their feeding relationships Producers on the first level, primary consumers on the second, etc. This works well if you are looking at a food chain but becomes more difficult when looking at real ecosystems in a food web

Trophic Levels As you move up trophic levels there tend to be less organisms and less energy, Why? Some times one organism, like a tree, can support many small organisms, but energy always decreases

Pyramid of Energy Pyramids of energy are a way to show how energy moves from one trophic level to the next Units are in energy/unit area/unit time Plants: 809 J/m2/yr Herbivore:37 J/m2/yr Small carnivore: 11 J/m2/yr Large fish: 1.5 J/m2/yr Parasite on fish: 0.01 J/m2/yr

Succession Ecological succession is a change in a community following a disturbance There are two kinds: Primary: when there are no living organisms Secondary: some organisms have survived

Succession The pattern of and causes of re-colonization will differ depending on the site and the reason for the disruption The species that colonize first will alter the environment and make it more hospitable for future organisms

Succession Research and describe one actual example of ecological succession

Succession What are some of the most common changes to an ecosystem during succession? Amount of organic material increases. As plants and animals die, they contribute to the organic component of the soil. Decomposers break this material down and recycle nutrients Soil becomes deeper Soil structure improves, increasing water retention Soil erosion decreases Amounts of nutrients increase Diversity of organisms increases and types of organinisms will probably change

Initially: Bare Ground No plant competition for light, space, nutrients or water. Soil mobile and liable to erosion and loss. A more extreme surface microclimate because the bare soil both absorbs and reflects heat more than soil covered in vegetation. A drier environment because there is no plant cover to hold moisture above ground and little humus to hold it in the soil. Lower nutrient levels in the soil . Two Years Later Intense plant competition for space and other resources. Soil bound by roots and plant cover. The plant cover provides a certain amount of ground insulation from extremes of temperature. There are now also a variety of microclimates within the vegetation. Plant cover and increasing humus levels help to retain water. The nutrient levels in the soil will have increased.

How do living things affect the abiotic environment? How can biotic factors affect water? Trees and other plants hold water in the soil,and reduce soil erosion. deforestation causes desertification

How do living things affect the abiotic environment? Temperature Living things generate heat as a byproduct so temperature can be affected Phytoplankton can cause localized increases in temperatures of aquatic systems

How do living things affect the abiotic environment? Carbon dioxide and oxygen levels are affected by organisms Amount of nutrients in soil are affected by decomposition of organic matter, this will also affect the quality of the soil as seen in succession.

Biomes and Biosphere G.2.9 Distinguish between biome and biosphere. Biome = Communities on earth that contain similar plant and animal inhabitants Biosphere = part of Earth that can contain life (incl: atmosphere)

Abiotic factors and distribution of biomes What abiotic factors most affect the distribution of biomes? Temperature and rainfall Climatograph is a graph of rainfall and temperature

Biomes Outline the characteristics of six major biomes. Characteristics: temperature, moisture, characteristics of vegetation. Biomes: desert, grassland, shrubland (chaparral, matorral, marquis, garigue, dry heathlands, fynbos), temperate deciduous forest, tropical rainforest, tundra

Example: Chaparral Found between 32 and 40 degrees latitude on the West Coast of continents. Dry climate Precipitation is mainly in winter Annual rainfall 300 to 750 mm in 2-4 month period. Plants: olive,shrub oak, maritime pine, eucalyptus Many plants have thorns

G.3 Biodiversity and Conservation Discuss reasons for the conservation of biodiversity using rainforests as an example Ethical Ecological Economic Aesthetic Give an account including a range of arguments, assessments of the relative importance of various factors or comparisons of alternate hypotheses

G.3 Biodiversity and Conservation Extinction of species: Almost a quarter of the world's mammals face extinction within 30 years, according to a United Nations report on the state of the global environment. One in eight bird species is also in danger of extinction, and more than 5,000 different plants. over 99 percent of the species that ever walked on Earth no longer exist. There is virtual unanimity among scientists that we have entered a period of mass extinction not seen since the age of the dinosaurs, an emerging global crisis that could have disastrous effects on our future food supplies, our search for new medicines, and on the water we drink and the air we breathe. Estimates vary, but extinction is figured by experts to be taking place between 100 to 1,000 times higher than natural "background" extinction.

G.3 Biodiversity and Conservation What is causing this acceleration of extinctions? Introduction of invasive species. These new speicies may be parasites, predators, compete for food, habitat. Often species are brought into an ecosystem to control some unwanted organism but the long term affects are hard to predict. The zebra mussel, accidentally brought to the United States from southern Russia, transforms aquatic habitats by consuming plankton and settling in dense masses over vast areas. At least thirty freshwater mussel species are threatened with extinction by the zebra mussel.

G.3 Biodiversity and Conservation Habitat destruction Humans destroy habitats of organisms when land is cleared for agriculture, buildings, roads, cutting forests, etc.

G.3 Biodiversity and Conservation Hunting, overfishing

G.3 Biodiversity and Conservation Pollution The Artic Char is a type of trout found in Lakes in Ireland In The early 1980s these fish were plentiful By 1990, the Char had gone extinct, due to pollution of lakes with fertilizers and other agricultural run off.

G.3 Biodiversity and Conservation

G.3 Biodiversity and Conservation Magnolias are one of the oldest flowering plants on earth. Several species are endangered due to habitat loss, clearing land for coffee growing, deforestation Magnolia sinica grows in China. There is only 1 population of 10 trees left.

G.3 Biodiversity and Conservation Simpsons Diversity Index Simpson's Diversity Index(actually your syllabus uses the SI reciprocal)l is a measure of diversity. In ecology, it is often used to quantify the biodiversity of a habitat. It takes into account the number of species present, as well as the abundance of each species.

G.3 Biodiversity and Conservation The value of this index starts with 1 as the lowest possible figure. This figure would represent a community containing only one species. The higher the value, the greater the diversity. The maximum value is the number of species (or other category being used) in the sample. For example if there are five species in the sample, then the maximum value is 5. D= diversity index N= total number of organisms of ALL species found n= number of individuals of a particular species High D suggests a stable, ancient site and low D suggests pollution, recent colonization or agricultural management

G.3 Biodiversity and Conservation Species Number (n) n(n-1) Woodrush 2 2 Holly (seedlings) 8 56 Bramble 1 0 Yorkshire Fog 1 0 Sedge 3 6 Calculate D N= 15 Sum of n(n-1)= 64 So the reciprocal of 64/210 D= 3.3

G.3 Biodiversity and Conservation How would you collect data to determine diversity in a particular location?

G.3 Biodiversity and Conservation Biotic Index is a way to determine if an ecosystem is polluted by looking at the type of organisms inhabiting that system. Some organisms are tolerant and some are sensitive.

G.3 Biodiversity and Conservation Species that serve as early warnings of damage to a community are called indicator species Trout is an indicator species in a river and gives an indication of water quality and oxygen levels

G.3 Biodiversity and Conservation Lichens indicate levels of sulfur dioxide Different species can tolerate different amounts of sulfur so this is a way to use a biotic indicator to estimate pollution

G.3 Biodiversity and Conservation Birds are good indicators since they are found in almost all communities and are sensitive to changes Scientist are trying to genetically engineer plants to indicate harmful biological or chemical agents that can be released by terrorists Barn owl

G.3 Biodiversity and Conservation Outline the damage caused to marine ecosystems by the overexploitation of fish About 3/4 of the world’s commercially valuable marine fish species are overfished or fished near their limits

G.3 Biodiversity and Conservation Overfishing is the greatest threat to populations that live near the surface Bottom dwelling fish are affected by overfishing and habitat destruction Overfishing leads to commercial extinction

G.3 Biodiversity and Conservation If areas are allowed to recover, reductions can be temporary But new methods of fishing are changing this Huge fleets of boats use sonar, satellite global positioning systems and aircraft to find fish Some ships are as large as football fields They deploy gigantic nets or lines that extend up to 80 k Modern fishing techniques can cause 80% depletion in 10-15 years

G.3 Biodiversity and Conservation Numbers of swordfish, marlin, tuna, and cod have reduced by 90% since 1952 North Atlantic cod may never recover because of the additional problem of habitat loss Larger fish are most vulnerable but smaller fish are also becoming affected The problem of bycatch is also made worse with modern techniques

G.3 Biodiversity and Conservation Fish are more endangered than any other group of species to to human activities: pollution, habitat loss, over exploitation and introduction of non native species

G.3 Biodiversity and Conservation What are international measures that could promote the conservation of fish? Due to the nature of fish habitats, this requires international efforts First it is important to identify which species are in danger, so countries need to work together to collect scientific data. The International Union for the Conservation of Nature and Natural Resources (IUCN) keeps Red Lists of species in danger of extinction

G.3 Biodiversity and Conservation National and International treaties to help protect marine species: Convention on International Trade in Endangered Species (CITIES), Global Treaty on Migratory Species, US Marine Mammal Protection Act ,International Convention on Biological Diversity

G.3 Biodiversity and Conservation Sea turtles: Kemp’s Ridley, Leatherbacks and Hawksbills are threatened due to: loss of egg laying habitat, overexploitation of eggs and turtles for food and jewelry and bycatch US shrimp trawlers used to kill as many as 55,00 sea turtles but since 1989 the US government requires trawlers to use turtle exclusion devices. Just changing the shape of the hook and bait can reduce turtle bycatch by 90%

G.3 Biodiversity and Conservation Conservationist can use two methods to protect species: In situ conservation- where organisms are protected in aquatic and terrestrial reserves and Ex situ conservation where organisms are captured and kept in zoos, gardens and seed banks

International treaties like the Convention on International Trade in endangered Species (CITIES) has been signed by 160 countries and lists 900 species that can’t be traded as live specimens or wildlife products because they are in danger of extinction

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