* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Ecological Concepts
Survey
Document related concepts
Storage effect wikipedia , lookup
Introduced species wikipedia , lookup
Restoration ecology wikipedia , lookup
Molecular ecology wikipedia , lookup
Biogeography wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Island restoration wikipedia , lookup
Biodiversity action plan wikipedia , lookup
Habitat conservation wikipedia , lookup
Microbial metabolism wikipedia , lookup
Renewable resource wikipedia , lookup
History of wildlife tracking technology wikipedia , lookup
Ecological fitting wikipedia , lookup
Lake ecosystem wikipedia , lookup
Human impact on the nitrogen cycle wikipedia , lookup
Transcript
Interactions: Environments and Organisms Chapter 5 1 Ecological Concepts • • __________ - Study of ways organisms interact with each other and with their nonliving surroundings. __________ - Everything that affects an organism during its lifetime. – Biotic - ___________________ – Abiotic - ______________________ 2 Levels of Organization in Ecology 3 Ecological Concepts • ____________ - Any factor whose shortage or absence restricts species success. – Range of Tolerance - Range of conditions an organism can survive in. Temperature pH DO 4 Habitat and Niche • • _______ - Space an organism inhabits; defined by biological requirements of each particular organism. – Usually highlighted by prominent physical or biological features. Niche - __________________________________ • Includes all ways an organism affects organisms with which it interacts as well as how it modifies its physical surroundings. Fig. 5.3 – • 5 Ecological Niche 6 Genes Population and Species • • ________ - Distinct pieces of DNA that determine the characteristics an organism displays. Population ____________________________________ ____________________________________ – Contains more kinds of genes than any single individual within the population. 7 Genes Population and Species • Species ____________________________________ ____________________________________ ____________________________________ ____________________________________ – Working definition that only applies to organisms that sexually reproduce. Some species are easy to recognize, while others are more difficult. 8 Natural Selection • • ______________ - Process that determines which individuals within a species will reproduce and pass their genes to the next generation. Conditions: – Individuals within a species show genetically determined variation. – Organisms within a species typically produce huge numbers of offspring, most of which die. 9 Natural Selection Conditions – – – Excess number of individuals results in a shortage of specific resources. Due to individual variation, some individuals have a greater chance of obtaining needed resources and thus have a greater likelihood of survival and reproduction. As time passes, percentage of individuals showing favorable variations will increase while percentage showing unfavorable variations will decrease. 10 Evolutionary Patterns • • __________ - A change in the kinds of organisms that exist and in their characteristics. – Ex. Building tolerance to pesticides. Speciation ____________________________________ ____________________________________ – Thought to occur as a result of a species dividing into two reproductively isolated subpopulations. 11 Evolutionary Patterns • • Extinction - Loss of entire species. – Of estimated 500 million species believed to have ever existed on earth, 98-99% have gone extinct. __________ - Two or more species can reciprocally influence the evolutionary direction of the other. – Grazing animals and grass species. 12 Kinds of Organism Interactions • Predation _____________________________________ _____________________________________ Prey adaptation is manifested in a higher reproduction rate. Fig. 5.7 13 Kinds of Organism Interactions – Prey species benefits by eliminating non-adaptive genes from the gene pool. Poorly adapted predators are less likely to obtain food and thus pass on non-adaptive genes. 14 Competition • • • Competition - Two organisms strive to obtain the same limited resource, and both are harmed to some extinct. – ___________ - Members of same species competing for resources. (Mice for Cheese) – ___________- Members of different species competing for resources. (Fox & Hawk for Mice) The more similar the competing species, the more intense the competition. Fig. 5.8 15 Competition • ______________________ - No two species can occupy the same ecological niche in the same place at the same time. – Less fit species must evolve into a slightly different niche. 16 Symbiotic Relationships • ___________ - Close, physical relationship between two different species. At least one species derives benefit from the interaction. – Parasitism ______________________________________ ______________________________________ ______________________________________ Ectoparasites - Live on host’s surface. Fleas Endoparasites - Live inside host. Tapeworms 17 Symbiotic Relationships • • Commensalism - One organism benefits while the other is not affected. – Remoras and Sharks ___________ - Both species benefit. Obligatory in many cases as neither can exist without the other. – Mycorrhizae 18 Community and Ecosystem Interactions • • Community - Assemblage of all interacting species of organisms in an area. __________ - Defined space in which interactions take place between a community, with all its complex interrelationships, and the physical environment. 19 Major Roles of Organisms in Ecosystems • Producers - Organisms able to use sources of energy to make complex organic molecules from simple inorganic molecules in the environment. – Ex. Grasses, Trees, Moss, Ferns 20 Roles of Organisms • __________ - Consume organic matter to provide themselves with energy and organic matter necessary for growth and survival. – Primary Consumers Herbivores (plants) – Secondary Consumers Carnivores (animals) Omnivores (plants and animals) – Scavengers (dead animals) 21 Roles of Organisms • • _______________ – Digest organic molecules in detritus into simpler organic compounds, and absorb soluble nutrients. (Bacteria and Fungi) Use non-living organic matter as source of energy. Keystone Species – Play critical role in maintenance of specific ecosystems. Bison in American Tall Grass Prairie 22 Energy Flow Through Ecosystems • Each step in the flow of energy through an ecosystem is known as a ___________. – As energy moves from one trophic level to the next, most of the useful energy (90%) is lost as heat (2nd Law of Thermodynamics). Because energy is difficult to track, biomass (weight of living material) is often used as a proxy. 23 Energy Flow Through an Ecosystem 24 Food Chains and Food Webs • • _________ - Passage of energy from one trophic level to the next due to one organism consuming another. – Some chains rely on detritus. _________ - Series of multiple, overlapping food chains. – A single predator can have multiple prey species at the same time. – Fig. 5.15 25 Food Chain 26 Nutrient Cycles in Ecosystems • Organisms are composed of molecules and atoms that are cycled between living and non-living portions of an ecosystem. – Biogeochemical Cycles - another name for nutrient cycles. 27 Carbon Cycle • Carbon and oxygen combine to form carbon dioxide. – Plants use carbon dioxide during photosynthesis to produce sugars. Plants use sugars for plant growth. Herbivores eat plants, and incorporate molecules into their structure. Respiration breaks down sugars releasing CO2 and water back into the atmosphere. 28 Carbon Cycle 29 Nitrogen Cycle • Cycling of nitrogen atoms between abiotic and biotic ecosystem components. – Producers unable to use atmospheric N. Must get nitrate NO3 or ammonia NH3. – ___________________ converts nitrogen gas N2 into ammonia. Legumes (Roots) Plants construct organic molecules. Eaten by animals. Drains soil of Nitrogen. – Decomposers also break down nitrogencontaining molecules releasing ammonia. 30 • • Nitrogen Cycle Nitrifying bacteria are able to convert ammonia to nitrite, which can be converted to nitrate. Denitrifying bacteria are able to (under anaerobic conditions) covert nitrite to nitrogen gas (N2) which is ultimately released into the atmosphere. 31 Nitrogen Cycle 32 Phosphorus Cycle • Phosphorus is not present in the atmosphere as a gas. – Phosphorus compounds released by erosion and become dissolved in water. Plants use phosphorus to construct necessary molecules. Animals gain necessary P via herbivory. Decomposers recycle into soil. 33 Phosphorus Cycle 34 Human Impact on Nutrient Cycles • Two activities caused significant changes in carbon cycle: – Burning of fossil fuels. (2001 – IPCC Report) Converting forests to agricultural land. Fossil fuel burning also increased amount of nitrogen available to plants. Fertilizer carried into aquatic ecosystems. Increase aquatic plant growth rate. Lowered oxygen concentrations. – • • 35 Review • • • • Ecological Concepts – Habitat and Niche Natural Selection and Evolution Organism Interactions – Predation – Competition Community and Ecosystem Interactions – Roles of Organisms – Energy Flow Through Ecosystems – Nutrient Cycles in Ecosystems 36 37