unit 3: Plants And Environment Flashcards
State the human effects on plant growth and distribution
trampling,habitat destruction,pollution,use of chemicals,over harvesting and monocultures
what is trampling and how does it effect
Footpaths and cattle tracks
It can flatten plants and alter which species grow in a habitat
Give examples of habitat destruction
Deforestation , clearing of land for agriculture or building
Give an example of pollution
Acid rain which destroys Habitats and kills plants and aquatic animals
Give examples of chemicals
Pesticides , fungicides , herbicides , fertilisers they all reduce biodiversity of an ecosystems
how would you estimate a population size
1)divide the area into a grid with numbered coordinates using string posts
2)use a random generator to produce points of coordinates to randomly choose position to sample
3)place quadrants at this point
4)count the number of individuals in the first quadrat
5)repeat the sampling and counting at least 9 times to obtain results of at least 10 set of results
6)repeat this method at both sites
7)produce a table of results
8) calculate mean value per m2 for each area
9)represent results as bar charts/histograms
-statistical analysis
how would you use a transect to measure the distribution of organisms from a field into a woodland
1)use a transect and position it so that it is in a straight line going through both the field and the woodland
2)use a 1m2 quadrat at start/0m and count the number of organisms lift and place
3)every 5 meters place a quadrat down , record and count
4)repeat 19 times to get a result of 20
5)bar charts, statistical tests
6)record other factors eg light intensity
how does over harvesting effect plant growth and distribution
deplete the soil of nutrients,preventing plants from growing as well
how does monocultures effect plant growth
growing one type of plant reduces biodiversity
what is aeration of soil
there are spaces between soil particles which allow oxygen to diffuse, for the plants to respire , for microorganisms to respire this is needed for decomposition and nitrification of the soil, helps plants absorb water and nutrients , prevents toxins forming , prevents plants contracting diseases
what pH do plants normally grow in
pH 4,5-7,5
why is light intensity important
-for plants to photosynthesise
-way they produce food
-plants grow more quickly in the summer when there is more sunlight
why is temperate important
-extreme of temperature can effect plant growth
-high temp can cause respiration to take place more quickly than photosynthesis
-products of photosynthesis are used up and plants cannot grow as quickly
-at low temp , photosynthesis is very slow which means plants grow poorly
-when the temp drops below 0C plant cells an tissues can be destroyed
why is water important
-water is taken up by the roots which is transported to the leaves for photosynthesis
-water also dissolved minerals in the soil which can be taken up by the roots
-if soil becomes waterlogged it can cause the roots to rot killing the plants
-plants loose water fro the leaves by transpiration so water has to be replaced continuously
-different plants need different amounts water
postive control?
full nutrients = healthy growth
