(SL) Unit Options (C); Topic C.1 Ecology and Conservation Flashcards
In ecology, a limiting factor is a
component of an ecosystem which limits the distribution or numbers of a population
A limiting factor defines optimal survival conditions according to what?
its effect on a species when in deficiency or excess
Limiting factors can be either…
biotic or abiotic
What are Biotic factors?
interactions between organisms – either intraspecific or interspecific
Define intraspecific and interspecific
intraspecific = within species,
interspecific = between species
What are Abiotic factors?
environmental conditions – such as light, temperature, salinity, rainfall, wind velocity, soil pH, etc.
What do you look for in an individual plant or animal to notice how they are adapted for survival in the unique conditions of their environment?
morphological, physiological, and behavioral characteristics.
what are morphological characteristics?
changes to the outward appearance of an animal as well as the form and structure of internal parts, like bones and organs.
(structures of the species)
What are the abiotic factors affecting the distribution of plant species?
temperature, water, light (intensity/wavelength), soil PH, soil salinity, mineral nutrient availability,
What are the abiotic factors affecting the distribution of animal species?
temperature, water, breeding sights, food supply, terriotry
explain an example of low-temperature adaptation in plants…
woody species of plants (e.g. Oak and Maple trees) synthesize ‘antifreeze proteins’ which prevents the formation of ice crystals inside cells. This enables these species to survive in temperatures as low as -40 degrees celsius, These species cannot survive at high temperatures as they transpire readily and will therefore dehydrate easily.
detail temperature and its effect on the distribution of the plant species…
plants can only survive in a range of temperatures to which they are adapted. Temperatures too high will denture the enzymes, these enzymes have optimal temperatures and control metabolic pathways. High temperatures also increase the rate of evaporation.
What are enzymes?
Proteins and catalysts
What does it mean for an enzyme to denature?
it means the structure of the enzyme will be lost.
What does the increase in the rate of evaporation lead to?
transpiration
detail water and its effect on the distribution of the plant species…
water availability limits plant growth in most terrestrial ecosystems. It is needed to maintain cell turgor, for photosynthesis and respiration to occur
what are terrestrial ecosystems?
ecosystems on land
what is cell turgor?
The pressure exerted by fluid in a cell that presses the cell membrane against the cell wall.
detail light and its effect on the distribution of the plant species…
light (intensity/ wavelength) limits the plants ability to carry out photosynthesis. Plants that grow in the share or lower light intensity contain more chlorophyll. P
detail soil pH and its effect on the distribution of the plant species…
Most plants only tolerate a narrow soil pH range. pH affects the availability of mineral nutrients, pH may affect the decomposition of organic matter and hence at the rate at which nutrients are recycled/made available to plants.
detail soil salinity and its effect on the distribution of the plant species…
most plants have a low soil salinity tolerance or can only tolerate a narrow range of salinity. High salinity makes osmosis by plants more difficult, or in extremes causes water loss.
what is osmosis?
the transport of a solvent through a semipermeable membrane that separates two solutions of differing solute concentration
or in this case an uptake of water
detail minerals nutrient availability and its effect on the distribution of the plant species…
minerals nutrient availability affects plant fertility, different plants needs minerals. Waterlogged soils encourage denitrifying bacteria and lower nitrogen availability to plants. Weathering of rocks often increases the availability of nutrients in the soil.
detail temperature and its effect on the distribution of the animal species…
temperature must be within a viable range (based on adaptations) for survival - few animals can survive extreme temperature conditions. Body size will determine an animal’s ability to conserve heat large body size means that heat is easily lost to / gained from the environment. homeotherms can colonize a wider range of habitats than poikilotherms.
what ratio is used for body size?
SA:Vol ratio
what are homeotherms?
organisms that maintain a stable internal body temperature
what are poikilotherms?
organisms where internal temperature varies considerably.
detail water and its effect on the distribution of the animal species…
water must be available in quantities sufficient for the particular species concerned.
detail breeding sites and their effect on the distribution of the animal species…
breeding sites are required for the maintenance of the species.
detail food and its effect on the distribution of the animal species…
food availability is critical in determining the maximum population size.
Can animals be specialized so that they will only consume a particular species of animal or plant>
yes
variations of what in food directly affect the abundance of the population
seasonal or geographical variation
detail territory and its effect on the distribution of the animal species…
not all animals are territorial, but those that may do so to attract mates, rearing young, forging for food, or to avoid predators.
How do animals mark territory?
by urinating or marking trees
what are examples of times spans that territories may be established for?
temporary (e.g for the duration of a breeding cycle) or permanent
establishment of territories can lead to what kinds of competition?
intra specific or inter specific
define intra specific
within species
define inter spesific
between species
what can you use quadrants to compare populations of plant or animal species for?
you can use it to compare populations of different species in the same area (species A vs species B)
or ro
compare populations of the same species in different areas (site A vs site B)
How do you conduct random sampling?
- map your area with a grid
- select coordinates for sample points randomly, using the random-number feature on your calculator, dice, or a random numbers table.
How do make sure the data collected is statistically significant?
- record as many samples as you can in the time allowed
-keep accurate notes and associated qualitative data
what do you count in a quadrant?
count plants only if they are attached to the soil within the quadrant: you may need to lift the flat laying foliage out of the way to see the roots.
What do you do with the data collected?
the data needs to be processed, presented, and tested for statistical significance. Comparing the two populations is an ideal candidate for the t-test.
line transacts can be used to correlate the distribution of a species with a what variable?
abiotic variable
what is a transact? and what does it do?
A transect is used to estimate species distribution over a set distance and in correlation with abiotic variables. This could be elevation, exposure, temperature, light levels, pH of soil, water content or more.
reminder: what is a abiotic variable?
a non-living part of an ecosystem that shapes its environment,.
How are line transects used?
the quadrants are placed at regular intervals and the populations of each species are recorded along with the abiotic variable
why are kite graphs often used to display the species distribution data?
because it allows the data to be presented in a clear and visual way.
why is Shelford’s law of tolerance a useful tool to understand?
it is useful to understand the relative abundance of a species and hence predict community structure.
What does shelfords law demonstrate?
it plots the range of a biotic or abiotic factor tolerated by a species
why is Shelford’s law of tolerance not easy to measure?
because there is a variability
