U2T4 - Keywords Flashcards
Hydrophytes
Adapted to live in water. Have adaptations to minimise gas exchange, especially since tissues are under water.
Arid
Having little or no rain.
Aerenchyma
Large air spaces.
Diurnal
Difference between hottest and coldest part of the day.
Competitors
Organisms compete for a resource which is in short supply, this results in a winner + a loser.
Intraspecific Competition
Organisms of the same species are competing for a resource.
Interspecific Competition
Organisms of different species’ are competing for a resource.
Ecological Niche
Organism’s role within ecosystem. What it feeds on, where it lives, climatic + edaphic factors it prefers + competition.
Competitive Exclusion Principle
No 2 organisms can occupy the same niche. If they do, it’d be competition + one species would have to lose.
Sampling
Ways to estimate the amount/abundance of organisms present in particular habitat.
Density
Number of individuals present, usually sampled using quadrats, most common way of sampling animals. Not suitable for all plants as some are hard to decipher where they start + end/
Percentage Cover
Usually for plants as difficult to distinguish between individuals, gives an estimation.
Frequency
Species recorded as present/absent at certain sampling point. Pin frames/point quadrats often used for this. 5% frequency = 5% pins used touched species. If a number of species touch pin, then they are also recorded.
Percentage frequency
Indicates percentage of all quadrats/sampling points in which a species occurs in.
Random Sampling
If area to be sampled is uniform/absence of clear pattern in species distribution, this is used. It avoids bias. Grid set out using tape measures at right angles, random numbers generated by calculator. Assuming distribution is relatively even.
Systematic Sampling
Used when zonation/clear transition from one habitat type to another occurs. Along a line or transect.
Line Transect
Sampling continually at intervals along transect line (tape). Only those touching tape are counted.
Belt Transect
Sampling along transect line using quadrats rather than tape. Percentage cover represented by line graph, histogram or kite diagram.
Interrupted Belt Transect
Sampling at intervals along overall transect due to large distance. e.g. Sand Dune 1km+. Several belt transects at intervals within overall transect. Use kite diagram for data especially if more than 1 organism present. Otherwise can use line diagram or bar chart.
Abiotic Factors
Non-living/physical factors. e.g. soil moisture, soil organic content, soil temp, soil pH + light intensity.
Edaphic Factors
Factors that relate to the soil.
Biotic Factors
Factors linked to living organisms. e.g. competition from other organisms + grazing.
Relative Light Intensity
e.g. Light reaching group in certain habitat as % of light reaching open group.
Pitfall Traps
Samples small group animals. Must sink trap sufficiently into soil so edge not above ground level, check regularly to avoid predation by other organisms.
