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Ecosystems

keefb56 Environmental Science Bachelors Degree Englisch 200 Karten

Leaf cutter ants and fungal garden are example of .....?

Karten in diesem Stapel (200)

  1. 1AbioticNon living components, but not dead matter
  2. 2Actual ETMeasured water loss< potential ET when water supply to surface limiting rate of loss
  3. 3Advectiontransport of properties by fluid motions
  4. 4AerenchymaHollow plant tissue in flood adapted scenario to allow gases to reach roots
  5. 5AlbedoProportion of reflected incidental light by a surface
  6. 6AlleopathyMechanism that allows some plants to restrict growth of competitors (e.g. toxins into soil from roots,leaves and litter)
  7. 7allocthanous Matteroriginating from outside the ecosystem and imported into it. Such inputs are often an important source of food for detritivores. (CB p.109)
  8. 8alternative stable statesEcosystem stability is related to both resistance and resilience. Sometimes for a given ecosystem there may be more than one stable state, and the change from one to the other is not gradual but the results of a change in condition, which takes the system across a threshold. (Block 3 Part 1.3)
  9. 9amensalismInteraction between two species such that one species suffers a disadvantage or cost, and there are neutral effects on the other. (CB p.6)
  10. 10ammonificationA reaction in which organisms break down amino acids and produce ammonia (NH3). (CB p.115)
  11. 11analysis of variance (ANOVA)A statistical method which exploits the reduction in total variation to determine the significance of particular factors. (Block 1 Part 5.2)
  12. 12angiospermsTrue flowering plants, such as Nuphar lutea (water lily). (Block 3 Part 1.4 Predicting outcomes)
  13. 13anoxicDescribes a system where oxygen availability is very low (e.g. less than 2% of the atmosphere) and thus largely unavailable to organisms. (CB p.86)
  14. 14AnthropoceneThe term for the most recent period of geological time that is defined by the effects of humans on the Earth system. There is debate as to when this started, with estimates ranging from ~250 years ago i.e. since the onset of the Industrial Revolution, to ~5000–7000 years ago. The term is used by some scientists but is yet to gain full acceptance.
  15. 15anthropogenicResulting from human activity. (Block 3 Part 1.2 ITQ 1.3)
  16. 16area-based modelSee population-based model. (Block 4 Part 2.4)
  17. 17assimilation efficiencyThe proportion of food consumed that can be assimilated. (CB p.14)
  18. 18assimilationThe uptake and retention in biomass of carbon compounds by organisms (primary producers and consumers). (CB p.106)
  19. 19benthic feederBottom-feeding, i.e. an organism than obtains food from sediments at the bottom of the water body, e.g. A. brama. (Block 3 Part 1.3)
  20. 20bioaccumulationBuild-up of toxins in an individual organism’s tissues; occurs when toxins are taken up or absorbed at a greater rate than that at which they are lost or broken down. (CB p.155 and p.194)
  21. 21bioamplificationThe increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain as a consequence of organisms eating other organisms at a lower level that have accumulated the substance. The organisms at the top of the food chain have higher concentrations of toxins in their tissues than would be expected from direct exposure alone. (CB p.155 and p.194)
  22. 22biodiversity hotspotsThe most ecologically rich and most threatened places on the planet. A biodiversity hotspot habitat contains at least 1500 endemic plant species. There are 34 global hotspots identified by Conservation International. (Block 3 Part 3.7)
  23. 23biomagnificationThe increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain as a consequence of organisms eating other organisms at a lower level that have accumulated the substance. The organisms at the top of the food chain have higher concentrations of toxins in their tissues than would be expected from direct exposure alone. (CB p.155 and p.194)
  24. 24biomanipulationThe deliberate alteration of an ecosystem by adding or removing species, especially predators (e.g. Abramis brama or Esox lucius respectively). (Block 3 Part 1.3 More on lake fish)
  25. 25biotic nitrogen fixation (BNF)The conversion of atmospheric nitrogen gas to ammonium compounds by living organisms such as cyanobacteria (blue-greens) and members of the bacterial genus Bradyrhizobium. (CB p.110)
  26. 26bioticPertaining to living organisms. (CB p.87)
  27. 27zoophagousOrganism that gains its nourishment by consuming animal tissues (carnivorous), e.g. many species of beetle and wasps. (Block 3 Part 4.3 Table 4.3)
  28. 28zooplanktonComponent of plankton that is not photosynthetic but grazes on the phytoplankton, e.g. tiny crustaceans like water fleas (Daphnia spp.). (Block 3 Part 1.2)
  29. 29xenobioticChemicals in the natural environment that are of human origin. (CB p.153)
  30. 30windthrowUprooting or stem break of trees due to wind. (CB p.22)
  31. 31water deficitWhen a vertical water balance is negative, water may be drawn from stores, such as the soil; the reduction in stored water is referred to as a deficit. Sometimes “moisture deficit” is used for the same concept. (CB p.66)
  32. 32water balanceThe sum of the water inputs and outputs of a subcatchment, which indicates whether storage within the subcatchment is expected to have changed. (CB p.66, Block 2 Part 1.5)
  33. 33wallowsShallow depressions, about 4 – 6m across where the soil is bare and impacted, where Bison habitually scratch and roll. (CB p.135)
  34. 34volatilisationThe process by which substances are lost from the soil by conversion to gases, which escape to the atmosphere. (CB p.110)
  35. 35vesicular-arbuscular mycorrhizas (VAM)Endomycorrhizas characterised by the absence of a fungal sheath and intracellular fungal structures such as vesicles and arbuscules. (Block 2 Part 4.3)
  36. 36vertical water balanceIncluding only the elements of a water balance that relate to vertical fluxes (i.e. precipitation and evapotranspiration) but excluding all horizontal fluxes (e.g. surface flows, throughflow and run-off). (CB p.66)
  37. 37verifyA checking process used to determine whether the model and its behaviour are a reasonable representation of the system under investigation. (CB p.26)
  38. 38valley of attractionLow-lying area of stability landscape that represents a relatively stable equilibrium condition of an ecosystem in that it resists change following perturbation. (Block 3 Part 1.3 Summary of ‘Flipping lakes’)
  39. 39validateA testing process that determines the extent to which the model output agrees with the behaviour of the real system. (CB p.26)
  40. 40trophic cascadePhenomenon in which even quite subtle effects on predators can be magnified in a downward flow of effects on grazers and plants in the lower trophic levels, i.e. a series of effects down the food chain. (Block 3 Part 1.4)
  41. 41turnover rateThe fraction of material that enters or leaves a pool over a specific time. (CB p.25)
  42. 42transpirationThe flux of water from its liquid state in plants to its gaseous state in the atmosphere. (CB p.66)
  43. 43trade-offAn evolved trait where an organism benefits from one characteristic (e.g. large stomata), allowing more rapid carbon uptake at the expense of another character (e.g. faster water loss), leading to less-efficient use of transpired water. (CB p.68, Block 2 Part 1.3)
  44. 44top-down controlControl of population or biomass that acts from ‘above’, i.e. from higher trophic levels such by predation (cf. bottom-up control). (Block 3 Part 1.4 Summary of ‘The tropic cascade’)
  45. 45timestepThe gap in time between successive states simulated by a numerical model, i.e. its temporal resolution. (CB p.202)
  46. 46throughfallWater that drops from the canopy of plants. (CB p.117)
  47. 47thermophilic‘Heat loving’, for example, thermophilic bacteria that thrive at high temperatures, such as hot springs. (CB p.120)
  48. 48theoretical modellingBased on theory or logic rather than on experimentation, observation or experience. (CB p.21)
  49. 49theoretical modelA scientific model constructed from previously established theories and relationships designed to simulate the real world based on the theoretical understanding of processes rather than direct observations of them. (CB p.21 and p.74)
  50. 50surface roughnessThe roughness of a surface affects the flow of liquids or gases over it due to frictional effects. Forests have higher surface roughness than grassland, which leads to a greater reduction in windspeed. (Block 4 Part 2.5)
  51. 51surface firesGround-level fires that are much less severe and are the type commonly used for land management. (CB p.145)
  52. 52summer-greenDeciduous in response to cold. (CB p.209)
  53. 53sulfate-reducing bacteriaBacteria capable of reducing sulfate to sulfide. (CB p.101)
  54. 54substrateAny substances that is consumed in an enzymatic reaction, such as organic compounds on which microbes feed. (CB p.90)
  55. 55stomatal conductanceThe ease with which gases can move into and out of the leaf via the stomatal pores: the wider open the pores, the higher the conductance. (CB p.69)
  56. 56stemflowWater that flows down stems of plants (from rain and snow, etc.). (CB p.117)
  57. 57stability and stable equilibriumThe ability of a population or ecosystem to stay at or move towards an equilibrium. An equilibrium may be locally or globally stable. Steady state is another term for stable equilibrium. (CB p.37, Block 3 Part 1.4 ITQ 1.22)
  58. 58species richnessThe number of species found in a given area. (Block 3 Part 3.3)
  59. 59sorbedA term embracing both adsorped and absorbed substances. (CB p.125)
  60. 60soil water potentialThe availability of water, measured in units of pressure, in the soil compared with a reference state of free water at ground surface. (CB p.79)
  61. 61soil respirationCarbon dioxide emitted from the soil to the atmosphere as a result of combined heterotrophic and autotrophic processes. (CB p.92)
  62. 62Soil organic matter (SOM)A mixture of soil components derived from dead organisms including decaying plant and animal parts, microorganisms and various slimy exudates; found mainly in soil A horizons. (CB p.90)
  63. 63simulation (for a climate model)Synonymous with run or integration, the process of producing a model prediction. (Block 4 Part 3.4)
  64. 64sign graphs (also known as causal loop diagrams)Diagrams of interconnecting factors linked by arrows; the arrows are marked with plus (+) or minus (–) signs, which indicate that a change in one factor gives rise to a change in the linked factor in the same or the opposite direction respectively. These diagrams can be used to identify feedback loops and distinguish between positive and negative feedback loops. (Block 4 Part 1.4)
  65. 65service providersThe idea that ecosystems can provide services, e.g. coastal protection by mangroves. (CB p.53)
  66. 66serotinyThe process in which seeds are held in long-lived woody fruits or cones, which are often attached to trunks or large branches and open to release seeds only after fire. (CB p.149)
  67. 67sensitivity analysisA process of testing a model to see how sensitive it is to changes in different parameters. (CB p.26)
  68. 68senescenceThe depression of body functions as part of the process of growing old. (PTG Section 2.1)
  69. 69semi-volatileCompounds with boiling points higher than water and which may vaporise when exposed to temperatures above room temperature; semi-volatile organic compounds can undergo repeated evaporation and deposition cycles in soil, air and water at ordinary environmental temperatures. (CB p.194)
  70. 70search timeHow long it takes a consumer to find a suitable food item. (Block 3 Part 1.4 Stability and exploitation of food resources)
  71. 71saproxylophagousSpecies that eat dead wood, e.g. woodworm beetles. (Block 3 Part 4.3 Table 4.3)
  72. 72saprotrophAn organism that feeds on dead or decaying plants or animals. (CB p.5)
  73. 73saprophagousOrganism that gains its nourishment by feeding on dead organic matter, e.g. woodlice, centipedes, springtails. (Block 3 Part 4.3 Table 4.3)
  74. 74runSee simulation. (Block 4 Part 3.4)
  75. 75run-offWater leaving a subcatchment as overland flow. (CB p.66, Block 2 Part 1.5))
  76. 76riskThe possibility of suffering harm or loss; a situation involving exposure to danger. (PTG Section 2)
  77. 77RiparianClose to or related to a river or stream bank. (CB p.90)
  78. 78ribulose-1,5-bisphosphate carboxylase oxygenase(Rubisco)The most abundant protein in the world. It is the enzyme responsible for converting carbon dioxide into sugar in photosynthetic organisms. (CB p.108)
  79. 79ribosomesOrganelles found inside cells that are involved in the synthesis of polypeptides and proteins. (PTG Section 5)
  80. 80rhizosphereA narrow zone of soil surrounding plant roots that is directly affected by exchanges of materials (such as water, oxygen, nutrients and plant exudates) between the roots and the soil. It is an area densely populated with microorganisms such as bacteria and an active site for processes such as energy exchange and nutrient cycling. (CB p.22)
  81. 81rhizosphereA narrow zone of soil surrounding plant roots that is directly affected by exchanges of materials (such as water, oxygen, nutrients and plant exudates) between the roots and the soil. It is an area densely populated with microorganisms such as bacteria and an active site for processes such as energy exchange and nutrient cycling. (CB p.22)
  82. 82responseThe reaction to a change in input to a system. (CB p.30)
  83. 83resourceDescribes an aspect of the environment for which organisms compete and which they consume (e.g. water, nutrients, light energy). Contrasts with condition. (CB p.84)
  84. 84resorptionThe process by which nitrogen and other nutrients may be withdrawn from senescing tissues into the perennial biomass before leaves are shed; otherwise known as internal recycling. (CB p.116)
  85. 85resolutionThe level of detail represented by a model, determined by the size or number of its grid cells. (CB p.202)
  86. 86resilientAn ecosystem that is resilient is one that is resistant to change and or recovers quickly following disturbance. (Block 3 Introduction to Block 3)
  87. 87resilienceMeasure of the ability of an ecosystem to resist change and or the rate at which an ecosystem recovers after a disturbance and returns to a steady state. (CB p.52)
  88. 88resilience hypothesisConcept that, following a change in environmental conditions, community composition follows a pattern of delayed recovery that is described by a catastrophe curve, in which there are alternative stable states. (Block 3 Part 4.3)
  89. 89residualThe difference (deviation) of an observed value from the predicted value in the regression. (Block 2 Part 2.1)
  90. 90reservoirThe amount of material stored in different parts of the environment; in practice it tends to be a term used for long term storage. (CB p.25)
  91. 91rendzinaA thin soil developed over a calcareous parent rock that has A and C horizons, but no B horizon. (CB p.197 Figure 12.10)
  92. 92regressionA statistical method which exploits the reduction in total variation to determine the significance of particular factors (Block 1 Part 5.2).
  93. 93reductionistAn approach to studying complex systems or phenomena by reducing them to their simple or fundamental components. (CB p.17)
  94. 94reanalysis dataData, based on observations, that have been reanalysed using models to remove random sources of variability and error. (Block 4 Part 3.4)
  95. 95rain-greenDeciduous in response to precipitation. (CB p.210)
  96. 96propagulesStructures that can give rise to new individuals, e.g. seeds, spores, bulbs, runners and cuttings
  97. 97process–function approachA way of looking at an ecosystem in terms of the processes and functions operating in that system, looking at the energy and materials that move through the system rather than being concerned with the organisms involved in the system. (CB p.31, Block 1 Part 3.4)
  98. 98potential ETThe atmospheric demand for water from a surface. (CB p.79)
  99. 99positive feedbackWhen new data facilitate and accelerate the transformation or action in the same direction as the preceding results, they are positive feedback – their effects are amplified. Positive feedback amplifies possibilities of divergences (evolution, change of goals); it gives the system the ability to access new points of equilibrium. (Block 3 Part 1.3 Positive and negative feedbacks)
  100. 100porometerAn instrument that measures the rate at which water vapour diffuses out of leaves. (CB p.73)
  101. 101populationA set of individuals of the same species, either within a given area or which are able to interbreed. A closed population is one without emigration or immigration. (CB p.24)
  102. 102population–community approachA way of looking at an ecosystem in terms of the organisms and populations within the system, rather than at the processes that operate within the system. (CB p.31, Block 1 Part 3.4)
  103. 103population-based model(also referred to as area-based) A type of dynamic global vegetation model in which the basic variables are averages over the entire population of plants of each type within a grid cell. (CB p.210, Block 4 Part 2.4)
  104. 104population regulationThe processes that produce persistence of a population at or around a certain population size. (CB p.39
  105. 105black boxAny component or subsystem in a system in which only the inputs and outputs are of interest, it is not necessary to define or understand the internal mechanisms or structures within the box, as its behaviour can be adequately explained by the inputs and outputs. (CB p.27)
  106. 106BoleThe trunk of a tree.
  107. 107bottom-up controlControl of an organism’s numbers or production by the supply of resources, e.g. food or mineral nutrients (c.f. top-down control).
  108. 108boundary layerThe portion of the atmosphere close to a surface, where air movement is limited by friction with the surface. It represents the boundary between the surface and the fully turbulent air above. The thickness of a boundary layer depends on wind speed and on the scale of the system – it can vary from a few millimetres around an individual leaf to a few metres above a patch of vegetation, to several kilometers when viewed at a global scale.
  109. 109C3-pathwayThe ‘conventional’ photosynthetic pathway in which carbon dioxide is fixed directly into a sugar. The initial sugar compound has just 3 carbon atoms
  110. 110C4-pathwayAn alternative photosynthetic pathway that uses an enzyme (PEP carboxylase) which is more efficient at scavenging carbon dioxide than the one (RUBISCO) used in the C3-pathway. Carbon dioxide is fixed into malic acid initially, which has 4 carbon atoms, hence C4-pathway. The malic acid is transported to photosynthetic cells, which re-release CO2 and use RUBISCO to refix it as sugar.
  111. 111canopy exchangeThe two-way movement of material between leaves and the wider environment, either through leaching by rainwater or absorption of nutrients dissolved from dust etc. that is deposited on leaves.
  112. 112cantharidinA poisonous chemical compound secreted by the male blister beetle and given to the female during mating, who uses it to cover her eggs with as a defence against predators.
  113. 113carrying capacity (K)The maximum density of individuals that can be supported by a given level of resources
  114. 114catastrophe curveGraphical representation of the relationship between two variables that can have alternative stable states.
  115. 115ChaosSituation where population density (or some other variable) fluctuates in an apparently unpredictable way, even though the dynamics are described by a deterministic (predictable) equation. This is in contrast to truly random processes. Chaos may occur when density dependence is coupled with high rates of population increase.
  116. 116charophytesGreen algae superficially resembling horsetail ferns, e.g. stoneworts.
  117. 117chelatesOrganic molecules that can bind to metal ions.
  118. 118chemoautotrophOrganism that uses energy derived from the oxidation of inorganic chemicals (rather than from light) to synthesise organic compounds.
  119. 119closed nutrient cycleA cycle in which nutrients are held tightly within an ecosystem, leading to efficient cycling
  120. 120closed systemsSystems that do not exchange materials andor energy with other systems. Few systems are closed and those that exchange only small amounts of energy or materials with other systems are described as ‘relatively closed’.
  121. 121coarse woody debrisThe largest organic matter-size fraction consisting of large pieces of wood, not normally considered part of the forest floor litter.
  122. 122commensalismAssociation between two organisms of different species from which one species gains an advantage without any positive or negative effect on the other.
  123. 123comminutionProcess by which conditioned litter is broken down into small particles.
  124. 124competitive exclusionEcologically identical species cannot stably coexist. Effectively, the niches of the competing species are identical.
  125. 125computational costThe amount of computational work to solve a problem; this translates into an amount of computer time that depends on the computer.
  126. 126conditionDescribes an aspect of the environment that affects the functioning of an organism but which is not consumed by it (e.g. temperature, soil pH, wind speed).Contrasts with “resource”
  127. 127conditioningProcess that makes litter palatable to detritivores.
  128. 128convectionVertical mixing driven by density contrasts. In the atmosphere, it is usually the result of local heating.
  129. 129coupledDescribes the extent to which the properties of the bulk atmosphere affect the rate of water loss from a canopy. The decoupling coefficient, Ω, describes whether a canopy is well coupled to the atmosphere (Ω value near 0), in which case the boundary conductance is high, or poorly coupled (Ω value near 1), in which case the boundary conductance is low. (CB p.77)
  130. 130crassulacean acid metabolism (CAM)The alternative photosynthetic pathway employed by many succulent species to overcome water limitation. The key aspect is that carbon dioxide is taken up at night rather than during the day. Like the C4-pathway, CO2is initially fixed as malic acid and stored overnight; being re-released and fixed as a sugar by the action of RUBISCO during the day.
  131. 131cross-scale effectsThe view that functional redundancy acting across different spatial scales is a significant factor in increasing the resilience of ecosystems.
  132. 132crown firesThe hottest and most devastating fires that move along the top of vegetation and spread down to soil level.
  133. 133cuticleThe outer layer of a leaf that is composed of waxes secreted by the epidermal cells.
  134. 134cyanobacteriaA group of photosynthetic prokaryotes (bacteria) that contain versions of chlorophyll that give them a blue–green colour; unlike green plants they can sometimes fix nitrogen; also known as blue–green bacteria algae.
  135. 135cyprinidSoft-finned, mainly freshwater fishes typically having toothless jaws and cycloid scales, such as A. brama; the family includes many benthic feeders, grazers and plankton feeders; family also includes carp, tench, roach, rudd and dace.
  136. 136decoupling coefficient– see coupled
  137. 137deep percolationWater draining through the soil into underlying permeable rock.
  138. 138delayed density dependenceThe survival, fecundity or migration rates of individuals in one generation are dependent on the density of individuals in the previous generation. An important factor underlying large fluctuations or cycling of predator and prey populations.
  139. 139denitrificationThe process in which nitrates are reduced to gaseous nitrogen or oxides of nitrogen. This process is used by facultative anaerobes. These organisms flourish in an aerobic environment, but are also capable of breaking down oxygen-containing compounds (e.g. NO3–) to obtain oxygen in an anoxic environment. Examples include the bacteria Pseudomonas (Smith, 1990).
  140. 140density dependenceVariables, such as survival, fecundity or migration, that change with density and thereby influence population dynamics. Density dependence is required for population regulation
  141. 141density-independentThis refers to models of population change in which population parameters such as survival or fecundity are assumed not to change with density, i.e. they are independent of density. (CB p.39)
  142. 142dependent (variable)Refers to a variable that changes in response to change in an independent variable.
  143. 143diazotrophsMicroorganisms that fix nitrogen.
  144. 144diffusionMixing or spreading, usually by unresolved processes.
  145. 145diffusivityThe rate of diffusive mixing.
  146. 146discrete logistic equationThis represents a simple mathematical model of regulated population dynamics. The regulation is achieved by incorporating density dependence into the equations.
  147. 147diurnal averageThe average over a one-day (24-hour) period. (Block 4 Part 3.4)
  148. 148DONDissolved organic nitrogen found in soils (for example amino acids).
  149. 149dynamic global vegetation model (DGVM)A computer model of global vegetation, including dynamic (disequilibrium) effects such as establishment and succession.
  150. 150Earth system modelA computer model of the Earth’s climate system, including some or all of its abiotic and biotic components. (CB p.201, Block 4 Part 1.4)
  151. 151ebullitionThe technical term for bubbling. (CB p.103)
  152. 152ecosystem demographyAn approach to terrestrial ecosystem modelling that represents the size and age structure of populations by dividing plant functional type populations into subclasses.
  153. 153ecosystemA set of organisms and abiotic (non-living) components that are linked by processes of energy transfer and material cycling.
  154. 154Name the seven type of interaction between organismsCommensalism,
    amenalism,
    mutualism,
    parasitism,
    predation,
    herbivory,
    competition
  155. 155OU definition of ecosystemsA set of organisms and abiotic components that are linked by processes of energy transfer and nutrient cycling
  156. 156name three mutualistic interactionsMycorrhizal-plant
    pollinator-plant
    single cell organism-digestive systems
  157. 157Food chains start with......?Autotrophs
  158. 158Formula for GPPGPP= NPP+R
  159. 159Formula for NPPNPP=T+D+C+S
  160. 160Leaf cutter ants and fungal garden are example of .....?microbivoryLeaf cutter ants and fungal garden are example of .....?
  161. 161two ways to increase food for decomposersconditioning and comminution
  162. 162Formula for consumptionC =A+U+F or consumed equals assimilated plus urine plus faeces
  163. 163Formula for assimilation efficiency?assimilated over consumed or A/C
  164. 164What is Lindemann's ratio and what does it apply to?An : An−1
  165. 165In ecosystem modelling what are the three types of systems approach?Reductionist and holistic or combined
  166. 166How are systems developed?Theoretically or empirically
  167. 167What is the Lotka-Volterra model? What assumptions are built in?It measures predator prey dynamics. One prey and one predator, and prey cannot escape predation.
  168. 168Steps in theoretical modelling?1) Identify system and boundaries
    2) define relationships
    3) Specify mechanisms
    4) Validate to reality
  169. 169Steps in empirical modelling?1) gather data
    2) determine relationships
    3) validate against known data
  170. 170What is a black box?Part of a model where the content or mechanisms are not understood but the input and outputs can be estimated empirically
  171. 171What two approaches are common in modelling ecosystems?Population-community where organisms are key or process-function
  172. 172zero or even minuses in a box and arrow model mean what?positive feedback which amplifies
  173. 173Odd minuses in a box and arrow model mean what?Negative feedback that balances
  174. 174What are the three key terms in ecosystem dynamics?Stability, equilibrium and perturbation
  175. 175How can stability be viewed?Via energy flow, material cycling or interactions
  176. 176What is the finite rate of population change?It is shown as lambda. It is as a formula the average proportion of individuals surviving to adulthood times the average number of offspring per mature individual. If > 1, population increases, if < 1 pop drops.
    If = 1 steady state (births equals deaths)
  177. 177What are the two population models?density independent or density dependent. DI's tend to be unrealistic but good over short time frames. DD's focus on fecundity and survival rates
  178. 178ecotoxicologyThe scientific study of the direct effect on ecosystems of xenobiotic chemicals. (CB p.154)
  179. 179ectomycorrhizaSymbiotic association between fungi (mainly basidiomycetes) and tree roots in temperate zones; characterised by presence of fungal sheath. There are usually no intra-cellular fungal structures. (Block 2 Part 4.3)
  180. 180emergent propertiesProperties that arise or emerge from the operation or behaviour of a system that cannot be inferred from the properties of the system components.
  181. 181emerging infectious diseaseA human disease that has become more common in recent years. (CB p.166)
  182. 182empirical modelA model based on data from observation or experience. (CB p.21)
  183. 183empiricalBased on experimentation, observation or experience rather than on theory or pure logic. (CB p.21)
  184. 184endomycorrhizaSymbiotic association between fungi and roots of plants; characterised by the absence of a fungal sheath but the presence of intra-cellular hyphal structures, such as vesicles, arbuscules and coils. (Block 2 Part 4.3)
  185. 185environmental toxicologyThe scientific study of the direct effect on people of xenobiotic chemicals. (CB p.154)
  186. 186epicormic growthTrees such as cork oak and some Australian eucalypts sprout rapidly after fire because dormant buds protected by bark are stimulated to grow by loss of foliage. (CB p.148)
  187. 187endophytesFungi or plants that live inside other plants, whether parasitically or not. (PTG Section 5.2)
  188. 188epigaeic [or epigeic]Surface-living organisms, e.g. spiders, ants, centipedes.
  189. 189equilibrium processA mechanism of population regulation in which population size is maintained around an equilibrium by the availability of resources or the action of competitors and predators (c.f. non-equilibrium process). (Block 3 Part 4.3)
  190. 190equilibriumA population or ecosystem is at equilibrium when the population size or components of the ecosystem remain the same from year to year. (CB p.37 and Block 3 Introduction to Block 3)
  191. 191ericoid mycorrhiza (ERM)Endomycorrhizas involving plants of the family Ericaceae (heathers, bilberries etc.), in which the fungal symbiont is mainly Hymenoscyphus ericae that forms a loose network of hyphae on the surface of the root and dense hyphal complexes within the root cells. (Block 2 Part 4.3)
  192. 192evapotranspirationThe combined rate of transpiration from vegetation with evaporation from other surfaces (e.g. open water or damp soil). (CB p.66, Block 2 Parts 1.3 and 1.5)
  193. 193excess waterThe quantity of precipitation falling during a defined period that is over and above the potential evapotranspiration occurring during the same period. That is to say the vertical water balance (P-E) is positive. (CB p.66)
  194. 194eutrophicIndicating a water body with high inputs of nutrients. (Block 3 Part 1.2)
  195. 195eutrophicationThe process by which water bodies are made more eutrophic through an increase in their nutrient supply. (Block 3 Part 1.1)
  196. 196exoenzymesEnzymes that are secreted from cells so that they act on substrates external to the plasma membrane. (CB p.118)
  197. 197external loadNutrient inputs into aquatic ecosystems – mainly from groundwater, fluvial and atmospheric sources. (Block 3 Part 1.2)
  198. 198extremophilesOrganisms (commonly microorganisms) that live in extreme environments. (CB p.96)
  199. 199facultative aerobic bacteriaBacteria that can switch from aerobic to anaerobic and back as environmental circumstances dictate. (CB p.119)
  200. 200feedback loopWhere a transformation or an action within a system impacts on other parts of the system and these impacts then produce an effect on (or feed back to) the system in either a positive manner (enhancing the first action) or a negative manner (damping down the first action). (Block 1 Part 3.3 and CB p.28)

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Bachelors Degree Environmental Science Karteikarten am Ecosystems, erstellt von keefb56 am 08/05/2016.
Erstellt von
keefb56
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