2 4 Ecology Organism Word Definition Organism A

2. 4 Ecology Organism Word Definition Organism A single living individual Ecosystem All interacting communities of organisms and abiotic factors of the environment within a defined area. Environment The sum total of all of the factors in the surroundings that influence an organism Abiotic factors Non-living chemical and physical factors of the environment (e. g. temperature, light, water, soil, nutrients). Biotic factors Includes factors such as food, organisms, competition. Predation, parasitism Climate Weather conditions in a certain geographical area averaged over a long period of time. Micro-climate local atmospheric zone where the climate differs from the surrounding area Weather Rainfall, temperature average (or highs and lows), sunshine hours and wind in a particular area at a particular time. Adaptation The feature that increases the chances that an organism will survive and reproduce. Structural; physical structure / feature of the organism Behavioural; certain behaviour of an organism Physiological; certain functioning of an organisms body Habitat The place where an organism lives Niche The way an organism makes it’s living; its role in the community Fundamental niche the full range of environmental conditions (biotic and abiotic) under which the organism can survive Realised Niche The niche that the organism actually occupies. Gause’s principle THE COMPETITIVE EXCLUSION PRINCIPLE If two species, with the same niche, coexist in the same ecosystem, then one will be excluded from the community due to intense competition. Tolerance An organisms ability to survive in a habitat with variation in environmental conditions Optimum range A habitat that has environmental conditions where a species will function at it’s best. Stress When the environmental conditions differ from the optimum range Acclimation When an organism can make adjustments to its tolerance levels over time to environmental conditions Liebigs’law of minimum It states that growth is controlled not by the total of resources available, but by the scarcest resource Limiting factors A factor that controls a process, such as organism growth or species population size or distribution.

It states that growth is controlled not by the total of resources available, but by the scarcest resource Liebigs’law of minimum Limiting Factor In the Ecosystem A factor that controls a process, such as organism growth or species population size or distribution. Affect each other Organism SJ Gaze acclimatation Optimum range Organism allow All together makes up one species Gause’s Principle If two species, with the same niche, coexist in the same ecosystem, then one will be excluded from the community due to intense competition. To live in tolerance A habitat that has environmental conditions where a species will function at its best.

2. 4 Ecology Populations Word Definition Organism A single living individual Population All the organisms of a given species occupying a defined area sampling Counting a smaller number of organisms and calculating the estimated population size or density in a given area. Quadrat sampling Population count of a individual taken within an area of defined size at selected points. Transect sampling Samples along a selected line (transect) through a community. Capture / Recapture Lincoln Index Total pop = No. of animals in 1 st sample (marked) x No. of animals in 2 nd sample ----------------------------------------------------number of marked animals in 2 nd sample (recaptured) Population number The total number of individuals of a single species in a defined area Density Population density is total population size per unit of area. Distribution The way individuals in a population are spaced from each other Clumped – focused around tolerance levels of niche Spaced – often seen in territories Random – not based on distribution of resources Age structure Defines the relative proportions of individuals of each age: a. Pre-reproductive b. Reproductive c. Post-reproductive Natality Birth rate, usually expressed as live births per 1, 000 persons per year Mortality Death rate Survivorship is the chance of an organism staying alive at any given age. Survivorship curves By plotting survivorship data on a log scale we can construct survivorship curves. There are three main types of survivorship curves. Type l - low mortality in the juvenile phase (humans) Type ll – constant mortality rate through all ages (jellyfish, birds) Type lll – high juvenile mortality (shellfish, plants) J - curves Exponential growth followed by a crash in numbers, overshooting the carrying capacity Sigmoid growth S – shaped growth curve in which numbers increase exponentially at first, followed by levelling off of growth rate till numbers stabilize at carrying capacity. Carrying capacity The maximum numbers of individuals that can be supported by a given environment Population growth= Births – Deaths + Immigration - Emigration R- Selected population growth Early reproduction, Short life span, High mortality rate, Little or no parental care, Large investment in producing large numbers of offspring, Below carrying capacity K-Selected population growth Late reproduction, Long life span, Low mortality rate, Extensive parental care, Greater investment in maintenance and survival of adults, At or near carrying capacity Population regulation Factors that control population growth; include density dependant and density independant Environmental Resistance Decreases the birth rate, or increases death rate, related to environmental conditions, such as food & space. Biotic Potential maximum rate at which a population could grow given optimal conditions (food, water, space) Density dependant factors Density independent factors Factors that become more inhibiting of growth as the density increases ; Food, Water, Shelter, Disease Growth Factors that are not influenced by the current density of a population; weather extremes, climate

K= carrying capacity Density dependent If none then population reaches biotic potential Food, Water, Shelter, Disease Organism Population growth Weather extremes, climate Density independent Population regulation Number of individuals in a defined area Density A single living individual Population number = 5 high low population Distribution All the organisms of a given species occupying a defined area Age Structure Random Mortality Natality Clumped Birth rate per 1000 Death rate per 1000 Uniform Survivorship curves slow growth Number of survivors (log scale) Rapid growth zero growth Type l - low mortality in the juvenile phase K-Selected population growth Late reproduction, Long life span, Low mortality rate, Extensive parental care, Greater investment in maintenance and survival of adults, At or near carrying capacity Type ll – constant mortality rate through all ages Type lll – high juvenile mortality R-Selected population growth Early reproduction, Short life span, High mortality rate, Little or no parental care, Large investment in producing large numbers of offspring, Below carrying capacity Percentage of maximum life span SJ Population Gaze

2. 4 Ecology Community Word Definition Community A area that contains populations of species interacting with each other – the biotic components of an ecosystem Environmental heterogeneity a range of resources in the natural habitat - allows one species to survive just beyond the niche limits of the other competing species. Zonation A graduated range of Abiotic factors (environmental) in an area - examples a rocky shore and altitudinal zonation up the side of a mountain. Stratification is caused by a vertical gradient of abiotic factors. This may be seen in a forest where variation in light levels and quality, temperature, wind, precipitation levels etc may determine the type of species found at each level Succession Changes in species distribution in time. Changing environmental conditions (abiotic) and the effect of previous species (biotic) provide newly available niches that new species can exploit. Intraspecific interactions Interactions between members of the same species Competition When two species or individuals compete for limited resources causing harm to both (or decreased benefits) Predation The killing of other organisms for food Predator-prey cycles The fluctuation in population number of predator which lags behind the rise and fall of prey – attributed to predation and environmental factors Territoriality means the claiming of space – and the resulting resources found within that space – food, water, nesting sites, even mating partners. Home range A home range is an area that an individual or group may occupy or be found at various times of the year. Interspecific interactions Relationships between members of different species. Mutualism Relationship between two species in which both species benefit – eg insect pollination Commensalism Relationship between two species in which one species benefits and the other is not affected. Amensalism The presence of one species harms another but it is not affected itself Exploitation Relationship between two species in which one species benefits at the expense of another – Predation – predator kills prey, Herbivory – Herbivore doesn’t kill plant, Parasitism – doesn’t kill it’s host Antibiosis Relationship between two species in which one benefits or is not affected while the other one is harmed –eg penicillin mould. Social organisation Interactions within a group of individuals of the same species which benefit the group as a whole – may not benefit certain individuals Individual (the female have dependant cubs with her) – eg, Polar bears Family groups collect food and raise offspring together – eg, nesting birds Extended Family groups often with a ranking of dominance (African hunting dogs) most females are related – male is not Networks of smaller groups joining together food, security – eg rabbits, Complex super organisations where there is a division of labour and niche – the entire colony acts as an entire organism eg termites, ants

Changes in species distribution in time Community Territory time Succession Zonation A graduated range of Abiotic factors (in an area Defending of space by a species Stratification a vertical gradient of abiotic factors Patterns location Community Home range Area an individual or group may occupy A area that contains populations of species interacting with each other Same species Environmental heterogeneity a range of resources in the natural habitat Intraspecific interactions Interspecific interactions Different species Exploitation Parasitism organism doesn't kill it’s host Herbivory Harmful relationships Competition for resources – food, space, light, nutrients, water, mates Consuming plants for food Predation killing of other organisms for food Predator-prey cycles Beneficial relationships Resource sharing – food, shelter Offspring / juvenile rearing Predation protection – warning, safety in numbers Social organisation SJ Individual Family Groups Extended Family Groups Networks Complex super organisations Gaze

2. 4 Ecology Ecosystem Word Definition ecosystem A community plus all the non-living matter in the area, e. g. a forest includes not only the inhabitants but also the non-living parts of the soil. Trophic level Position of an organism in a food chain; plants occupy the first trophic level and herbivores the second Food chain A series of organisms through which energy flows, the first link is always a producer. Food web A series of food chains linked together showing the feeding relationships of all species in a community. Producer Species occupying trophic level one, the plants and phytoplankton that convert suns energy into food by the process of photosynthesis Consumer An organism that feeds off another organism, either plant or animal or fungi – often killing them in the process Decomposer An organism that feeds of dead organic material returning nutrients into the ecosystem Energy Entering the ecosystem from the sun, about 1% gets converted to chemical energy but photosynthesis Pyramids of energy These show the proportion of energy stored at each trophic level, approximately 10% get passed on to each successive trophic level. Pyramids of numbers Showing the number of organisms at each level required to feed one top carnivore. Pyramids of biomass The total dry weight of organisms (standing crop) in a particular trophic level. Organisms vary greatly in size, often being larger the further up the trophic levels, so a pyramid of biomass more accurately reflects the transfer of energy. Heat energy Pyramids of biomass decrease from one trophic level to the next. Energy, in the form of heat energy is wasted at each step in a food chain. This is due to: – respiration using up energy for movement and warmth; – energy (heat) lost to the surroundings; – energy and materials lost in excretion Biochemical cycles Nutrients are continually recycled between the abiotic environment and the biotic communities Carbon Cycle Carbon is circulated through the ecosystem from CO 2 in the atmosphere to carbon in organisms (via the photosynthesis process of plants). It is released back to CO 2 by respiration, decomposition after death, transformation into fossil fuels (over millions of years) and eventual combustion (burning) Nitrogen Cycle Nitrogen gas in the atmosphere is fixed into useable form by 1) nitrogen fixing bacteria (in legumes) and nitrifying bacteria in nitrates or 2) lightning. The plants can take up the nitrates through their roots and convert them to amino acids → then protein which can be passed along the food chain to consumers. Bacteria can either decompose organisms back into nitrates for plants or into N 2 gas (denitrifying bacteria) Phosphate cycle Plants uptake phosphates from the soil through their roots. This is passed on to the next trophic level through consumption. The phosphates are released back into the soil by decomposers (bacterial or fungal) Water cycle The water or hydrologic cycle refers to the continuous circulation of moisture on earth, particularly between the atmosphere and the earth’s surface. Solar radiation provides the energy for the water cycle. Water changes between gaseous and liquid states through the processes of transpiration, evaporation, and precipitation.

ONE WAY travel of energy through an ecosystem Consumer An organism that feeds off another organism, either plant or animal or fungi – often killing them in the process Energy lost through respiration and heat Decomposer Energy lost through consumption photosynthesis An organism that feeds of dead organic material returning nutrients into the ecosystem Energy lost through death A series of organisms through which energy flows, the first link is always a producer. Ecosystem Energy Circular travel of nutrients through an ecosystem Nutrient cycles respiration N 2 These show the proportion of energy stored at each trophic level CO 2 Carnivores respiration Herbivores ammonification ammonium NH 4+ Producers nitrification Gaze death C NO 3 Nitrates NO 3 - Showing the number of organisms at each level required to feed one top carnivore. fossilisation assimilation Nitrogen fixing bacteria Fossil fuels Decomposers decomposition - N 2 CO 2 10% passed on to each level Pyramid of numbers combustion consumption Carbon Pyramids Pyramid of energy respiration photosynthesis Trophic Levels Ecosystem Food chain Entering the ecosystem from the sun, about 1% gets converted to chemical energy but photosynthesis SJ Position of an organism in a food chain decomposer Light energy producer Species occupying trophic level one, the plants and phytoplankton that convert suns energy into food by the process of photosynthesis consumer Producer Consumer, producer or decomposer Pyramid of biomass The total dry weight of organisms (standing crop) in a particular trophic level