Biodiversity 4.2 Flashcards
(43 cards)
1
Q
biodiversity
A
the variety of species found in a ecosystem and the variety of genes
2
Q
importance of biodiversity
A
interdepence of species
3
Q
habitat biodiversity
A
- different types of habitats you can have in a particular area (e.g. sand dunes,
woodland, meadows, streams)
4
Q
species richness
A
the number of different species
5
Q
species evenness
A
- a measure of the relative abundances of species within a community
6
Q
how do we calculate the diversity of a habitat?
A
- Simpson’s index
D= 1- sum of number individuals in one species/total number of individual species squared, - high simpson’s index value indicates a diverse habitat
7
Q
genetic biodiversity
A
- total number of different alleles in a population.
8
Q
how do we calculate genetic biodiversity
A
- n.o of polymorphic loci/total of loci x 100
9
Q
random sampling
A
- the positions of the sampling points are completely random or due to chance. random generated numbers as coordinates for samples can be used.
- ensures that data is not biased by selective sampling
- may not cover all areas of a habitat species equally. species with a low presence may be missed leading to an underestimate of biodiversity.
10
Q
opportunistic sampling
A
- involves picking and choosing sampling locations based on various non-random factors.
- easier and quicker than random sampling
- data mat be biased. presence of a large colourful species may entice the researcher to include that species leading to a overestimate of biodiversity.
11
Q
systematic sampling
A
- samples are taken at fixed intervals across the habitat
- belts and line transects can be used as systematic techniques
- useful when the habitat shows a clear gradient in some environmental factors
- other species not on the line or within the belt may be missed, leading to a underestimate of biodiversity
12
Q
stratified sampling
A
- involves matching the number of sampling locations in a particular habitat with the relative proportion of area that habitat covers in the whole area being studied.
- representable of the population
- could possibly lead to a over-representation of some areas in the sample
13
Q
quadrats
A
- used in random sampling
- square frame
- numbers can be generated and used as coordinates to place the quadrats accurately.
- inside the quadrat percentage cover needs to be calculated as a measure of their abundance
- percentage cover can be measured using a point frame. lower the frame into the needle and record any plant touching the needles.
14
Q
transects
A
- taken across a habitat by stretching string or tape measure across the habitat.
- large habitats a line transect may be used where you record the plants touching the line at set intervals along it.
- quadrat may be used at set intervals( interrupted belt transect).
- continuous belt transect can be used where a quadrat is placed beside the line and moved along the line so you can study a band or belt in detail
15
Q
ecological reasons to maintain biodiversity
A
- keystone species need to be protected as they have a disproportionate effect upon its environment relative to its abundance. interdependence of organisms
- decline of a keystone species could result in less food for another species therefore there population also decreases.
- maintaining genetic resources
- decline in biodiversity= decline of genetic diversity meaning plants and animals that have adapted to solve our problems are lost.
- molecules valuable in developing a new and effective pharmaceutical product may be lost.
16
Q
economic reasons for maintaining biodiversity
A
- ecotourism
- reducing soil depletion caused by continuous monoculture as the soil becomes less fertile so declines agricultural yield. This is because the crop takes the minerals out of the soil, and when the crop is harvested these minerals are removed from the ecosystem. soil depletion has a effects around the world such as landslides and floods, an increase in pollution, desertification and a decline in global food production
17
Q
techniques in sampling animals\
A
- pooters. suitable for low vegetation that is not too woody.
- sweep nets. Used long grass. insects are caught and emptied of a white sheet to be identified. be careful the insects do not crawl or fly away
- pitful taps. trap set in soil to catch small ground insects. should be sheltered in rainy weather so it doesn’t fill up
- A tullgren funnel. leaf litter is placed in funnel. a light above the litter drives the animals downwards as the litter dries out and warms up.
- kick sampling. used to catch freshwater invertebrates living in streams or rivers. A net in placed on the stream-bed so that the water is flowing into it and the stream-bed just above the net is churned up by the scientist (using their foot) for a set period of time.
18
Q
aesthetic reasons to maintain biodiversity
A
People find it beautiful to look at
- to be enjoyed by future generations
19
Q
capture-recapture technique
A
- first the sample of animals is captured
-marked harmlessly
-released
-recaptured
calculate the total population = number of individuals initially marked x number of individuals recaptured/ number of individuals recaptured already marked.
20
Q
factors affecting biodiversity
A
- human population growth= increased demand for food and consumer goods
Humans alter ecosystems to provide ourselves with food, destroy and fragment habitats, use more of the earths resources, pollute the atmosphere. - monoculture is when areas are cleared to grow one strain of a species. reduces genetic diversity as the population of species is decreased
- selective breeding decreases genetic diversity as farmers select particular traits ignoring other characteristics. other breeds become rare and may die out resulting in a loss of biodiversity known as genetic erosion.
-climate change caused by humans is now occurring too fast for many species to be able to adapt to these changes, which could result in many species becoming extinct and a major decline in biodiversity
-global warming is causing many species to move towards the poles. However, these species may not be able to compete with, or may even out-compete, the species already present in these habitats, with either result leading to decreased biodiversity. - some species may not be able to adapt to increasing temperatures fast enough and may go extinct as a result
-increased CO2 production may kill of species.
21
Q
conservation in situ
A
- carrying out active management to maintain the biodiversity in the natural environment
22
Q
examples of in situ conservation schemes
A
- wildlife reserves such as national parks.
-areas within countries where the wildlife and environment are protected
Governments control these areas and pass legislation to ensure their protection
There are several restrictions: Humans access is strictly controlled, Industrial activities such as agriculture and building are tightly regulated, Hunting is limited or completely prohibited
-Marine parks are protected areas of water that have been set up for the conservation of endangered marine ecosystems and species. They also have restrictions to prevent overfishing and pollution
23
Q
advantages of in situ conservation schemes
A
- more likely to survive in the wild
-can protect the whole population - less disruption to the animals
24
Q
disadvantages of in situ conservation
A
- hard to enforce bans on hunters/poachers
-can’t protect from predation and intraspecific competition - no protection from climate change
25
conservation ex situ
Protecting animals and plants away from their natural habitat
26
example of conservation ex situ
-zoos- captive breeding programmes can breed individuals of a species so their offspring can be released into the wild. modern reproductive technologies such as freezing sperm, eggs or embryos, artificial insemination, IVF can be used
Zoos are an invaluable resource for scientific research. Scientists are able to closely study animal’s genetics, behaviours and habitat needs.
- Botanic gardens- use cuttings and seeds collected from the wild to establish a population of the endangered species in captivity. Methods of tissue culturing and cloning can also be used to obtain large numbers of plants from a small sample size
The captive population can be used in the future for reintroduction into habitats where they have become rare. allows research to investigate reproduction and growth in different plant species so that they can be grown in captivity . If the plants original habitat no longer exists they try to find suitable new habitats
- seedbanks
27
examples of storing genetic material for Conservation
-Frozen zoos store genetic material from animals (eggs, sperm, tissue samples etc) at very low temperatures so that they can be kept for a very long time.
-A large amount of genetic material can be stored in a relatively small space
-In the future genetic materials from extinct animal species could be used to breed and reintroduce a species through IVF and genetic engineering
-A seed bank is a facility that conserves plant diversity by drying and storing seeds in a temperature controlled environment
Usually, seeds of the same species are collected from different sites to maintain the gene pool
-If the plant species goes extinct then the seeds can be used to grow them again
28
disadvantages of ex situ conservations programmes
- captive population is likely to have a limited genetic diversity
- breeding can be less successful in captivity
- when reintroduced, there can also be difficulties with acceptance by existing wild members of their species therefore less successful
- can be expensive to set up e.g. botanic gardens are difficult to find
-ethical reasons- caging animals can only care for small numbers
29
CITES
-stands for conservation on international trade in endangered species
-regulates and monitors trade in selected species
-ensures trade in animals does not threaten wild populations therefore less endangered animals can be traded
-prohibits the commercial trade of wild plants
30
Rio convention on biological diversity (CBD)
- promotes sustainable use of organisms/habitats and ecosystems
- share genetic resources
-share scientific knowledge
-raises the profile of biodiversity with governments
31
Country stewardship scheme (2005)
- provides funding to farmers + other land managers in England to deliver effective environmental management on their land
- provides funding to land managers to conserve, enforce + promote the countryside by looking after wildlife species and their many habitats, protecting historic features and natural resources.
-- improve the natural beauty and diversity of the countryside
- improves opportunities for public access
32
the importance of sampling
- provides an estimate for the whole habitat
- impossible to count every individual
- counting every individual is too time consuming
- sample representative of the whole are
33
what does a low Simpson's index value suggest
- a habitat is dominated by one species therefore is unstable and unable to withstand change. a small change in the environment that affects one species could damage or destroy the whole habitat.
34
species
-breed to produce fertile offspring
35
Habitat
the area where individuals in a species live
36
how would you describe a high simpsons index value
- has biodiveristy therefore has a high species richness and species eveness
- this mean the ecosystem is stable and liekly to withstand change
-
37
how would you describe a low simpsons index value
- Domimated by one species
- change in one species is likely to affect the whole habitat therefore the ecosystem is unstable and unliely to withstand a change
38
Why is it better to store seeds than adult plants
- can be collected without damage to the plants
-take up little space
-can store a large number
-viable for long periods
-less suspectible to disease
39
Advantages of Ex situ conservation
- feeding the animals well
-treated for disease
-protection from hunting/preachers
- reduced intraspecifc variation
-mating- artificial selection which can be used to maintain genetic diversity
40
Why is randomisation important
To avoid bias
41
How to deduce how samples to use ?
-must be representable
-to calculate the mean
-avoid recounting the same plant
-sample at different times of the year/month/day
42
How to use a belt transect
-Use a qudrat; every ....m;
count the number of organisms of each species; use an identification key; use a method to avoid recounting; calculate a mean. Repeat at different times of the years
43
How to measure biodiversity in a field
use 2 tape measures to make a grid; generate random coordinates;
use a quadrat at those coordinates to count the number of individuals of each species; use an identification key; use a method to avoid recounting; sample at different times of the year;
