Biodiversity

what is a biosphere

living organisms do not live in isolation but are always interacting with one another and their abiotic environment

give an example of a small ecosystem

a pond

give an example of a large ecosystem

a rainforest

what is an ecosystem

interactions between living and non-living aspects of the environment

what is a biome

• particular abiotic factors

• leads to an abundance of particular flora and fauna characteristics of that environment

what is biodiversity

the variety of living organisms present in an area

what is global biodiversity

• all the different plants, animals, fungi and microorganisms species worldwide

why is measuring biodiversity important

• important indicator of stability of ecosystems

• essential for conservation to allow scientists to track changes over time

what is species richness

• the number of different species in an area

what is species evenness

the number of individuals of each species within the community

what is habitat biodiversity

• the number of different habitats found within an area

• each habitat supports a number of different species

what is genetic biodiversity

the variety of genes that make up a species

what occurs when there is a high genetic biodiversity

a variety of characteristics exhibited within a species and better adaptation to a changing environment

what is a species

a group of organisms with similar morphology and physiology

they are able to interbreed to produce fertile offspring

what is a community

All the populations of different species living and interacting in the same area at the same time

what is an intraspecific competition

• competition between the same species

what is interspecific competition

competition between members of different species

what is an abiotic factor

a non-living environmental influence on an organism

what is a biotic factor

all the living organisms of all species living in the same place at the same time

what is a niche

the role of a particular species of organism in the community and the way in which it responds to environmental factors

what is a population

• a group of organisms of the same species, living in the same place at the same time

how are domestic dogs created

• selectively breeding individuals with the traits that they want

describe the genetic variability within domestic dog breeds

• genetic variation within breeds decreased because their effective population size is limited by humans controlling their access to mates

describe the genetic variability among domestic dog breeds

• increased as the different breeds diverged

what is the net effect of domestic dogs

• a population with more genetic diversity than their closest wild cousin, the wolf

what are the ways in which a species can become less genetically diverse

• if isolated from a population of members of its species

• (founder effect)

• if a disease or volcanic eruption cause population numbers to drop suddenly

• (genetic bottle neck)

describe the cheetahs genetic bottleneck

• around 10,000 years ago

• population was reduced to very low numbers and the remaining animals became inbred

• low genetic variability makes lethal genetic disorders more common- low reproductive success

• may be a millennia before they fully recover their genetic diversity

what are the levels at which biodiversity can be evaluated

• genetic, habitat, speciesn

why is biodiversity important

• it provides ecosystems with resilience so they are more able to survive in the face of change

• interconnections between species in turn strengthens the individual component of the ecosystem

what happens if biodiversity is reduced

• it has the potential to harm all species in the ecosystem

• only relatively few species may be directly impacted

what is a keystone species

• a species involved in a lot of processes to aid the habitat

• if it dies it would have a big impact on the whole ecosystem (domino effect)

what is genetic biodiversity

• the more alleles present in the population= the more genetically biodiverse the population is

what is the effect of a species having high genetic biodiversity

• more likely to be able to adapt to changes in the environment

what are the factors that lead to increased genetic biodiversity

• mutation- spontaneous changes to DNA that create new alleles

• interbreeding between different populations, leading to alleles being transferred between the populations- gene flow

describe selective breeding

only individuals with desirable traits are allowed to breed

reduces genetic biodiversity

describe captive breeding

• zoos may only have a small number of captive individuals of a species available for breeding

• the zoo keeper selects the parents

what is a genetic bottleneck

• genetic biodiversity can be reduced by a sudden decrease in population size

• resulting in the loss of alleles

how do you calculate genetic biodiversity

proportion of polymorphic gene loci- number of polymorphic gene loci/total number of loci

what are polymorphic genes

genes that have more than one allele

what are monomorphic genes

genes that only have one allele

what is the effect of polymorphism on genetic biodiversity

higher proportion of polymorphism= higher genetic biodiversity

what are the main problems of human population growth on biodiversity

• deforestation

• agriculture

• climate change

how does deforestation affect biodiversity

• habitat loss- reduction of species

• decreases species biodiversity- decreased population size of species (loss of alleles)

• soil erosion- decreased nutrients

how do agricultural techniques lead to a reduction in biodiversity

• removal of hedgerows- reduces habitat biodiversity

• use of chemical pesticides and herbicides- loss of species and genetic biodiversity- potential loss of pollinators

how does climate change impact biodiversity

• extinction of arctic/antarctic animals and plant species

• migration of animal species further north/south- changing the distribution of species

• flooding of low-lying land- fewer terrestrial habitats

• temperature changes- change in growth patterns

describe the number of successful species in an area of high/low biodiversity

• high- a large number

• low- relatively few

describe the nature of the environment in an area of high/low biodiversity

• low- stressful and/or extreme with relatively few ecological niches

• high- relatively benign/not stressful- more ecological niches

describe the adaptation of species to an environment in an area of high/low biodiversity

• low- relatively few species live in the habitat- with specific adaptations for the environment

• high- many species- few specific adaptations

describe the type of food webs in an area of high/low biodiversity

• low- relatively simple

• high- complex

describe the effect of a change to the environment on the ecosystem as a whole in an area of high/low biodiversity

low- major effects on the ecosystem

high- ofte relatively small effect

what is sampling

• investigating a subset of a population or community

why is sampling used

it is quicker and easier than investigating the whole population or community

what are sweep nets used to collect

• flying insects

• insects on top of vegetation

• insects can be transferred to a ziplock bag where they can be further inspected and identified/counted

how can you standardise sweep netting

• same sweeping method

• same no. steps per sweep

• if doing a transect- one sweep per step

what is tree beating used to collect

• mainly used for crawling insects

how do you carry out tree beating

• brushing insects on vegetation onto a sheet and beating/catching the insects on a sheet

what are pooters used to collect

individual insects

what is kick sampling used to observe

• invertebrates in streams and small rivers

how is kick sampling carried out

• kicking the sediment in a river/stream and hold the net downstream from where you are kicking

how do you standardise kick sampling

• use the same net and same number of kicks

why is standardisation needed in sampling

• to ensure consistentdata collection and comparability of results across different sampling sites.

describe pitfall traps

• imbedded into the ground

• cover protects trap from rainfall so caught insects don’t drown

what are pitfall traps used to collect

• crawling insects that live on the floor

what are quadrats used to sample

• immobile organisms- such as plants

what are gridded quadrats used to measure

percentage cover of plant species

what are the aspects you can measure using quadrats

• species density

• frequency of occurrence of organisms

• percentage cover

• estimate for species abundance using ACFOR/SACFOR scale

what does SACFOR stand for

• super abundant

• abundant

• common

• frequent

• occasional

• rare

what does ACFOR stand for

• abundant

• common

• frequent

• occasional

• rare

describe point quadrats

allows sampling of tall/overlapping vegetation

describe random sampling

• samples are taken at randomly selected sites

• a marked-out grid and a random number generator are used to create random coordinates

• used to get an overall idea of the abundance of each species

describe non-random sampling

• sites are chosen based on specific criteria or characteristics

• often used when certain areas are of particular interest for study

• more systematic

• doesn’t give all individuals an equal chance of being selected

describe systematic sampling

• samples are taken at regular intervals- ensuring complete coverage of the area

• used to detect changes in abundance of a population or community along a transect

describe opportunistic sampling

• uses organisms that are conveniently available

• not very reliable

• easy

describe stratified sampling

a random sample is taken from each subgroup or stata of the population- e.g. male and female

why is stratified sampling used

• it obtains representative results

what is an interrupted transect

• gap is always the same distance between transects- e.g. one meter

what are the pros and cons of interrupted transects

• good for long transects- because it is quicker

• misses out some data in the transect- pattern may not be as clear

describe continuous transects

no gaps between the data collection

what are the pros and cons of continuous transects

• easy for a pattern to be detected

• slower- less ideal for long transects

what is Simpson’s diversity index

• gives community a number between 0 and 1 that indicates it’s biodiversity

• a community with a low number has a low diversity and a community with a high value has a high biodiversity

• takes into account species richness and evenness

what is the formula for Simpson’s biodiversity index

D= 1- {(n/N)²

n= number of individuals of a particular species
N= total number of individuals of all species

what is conservation

active management by humans of an ecosystem to restore biodiversity

describe preservation

leaves ecosystems undisturbed (no human intervention) in order to maintain biodiversity

why is conservation of biological resources important for economic reasons

resources needed to survive and provide income

e.g. timber managment

why is conservation of biological resources important for social reasons

people enjoy natural beauty

why is conservation of biological resources important for ethical reasons

humans have responsibility to conserve existing ecosystems for future generations

what is sustainable development

• new projects undertaken in order to meet the needs of people today without impacting future generations

• important when considering land use

describe CITES

• an agreement between international governments to regulate the trade of endangered species

• endures trade doesn’t endanger wild populations

describe the Rio convention

• international meeting which emphasised the need for sustainable use of ecosystems

• allowed sharing of genetic resources and access to scientific knowledge and tech

• promoted ex situ conservation methods

what is in situ conservation

in the animals natural habitat

what is ex situ conservation

in the animals non-natural habitat

e.g. a zoo

describe the millenium seed bank

• underground collection of seeds conserved for the future

• at any point in the future they would be able to germinate and reintroduce the plants back into the wild

what are the advantages of seed banks

• possible to conserve the diversity of plant species

what are the disadvantages of seed banks

not a viable option for all plants in the world

what are the aesthetic reasons for maintaining biodiversity

• humans experience pleasure and sense of wellbeing when being in a beautiful environment

• inspiration for musicians and writers

what are the ecological reasons for maintaining biodiversity

• removing one species will have effects on all other species due to interdependence between species

• high biodiversity maintains the gene pool which provides protection against weather events, natural disasters and diseases

what is lundy island conservation zone and what do they do

• protected marine area in the bristol channel

• protect rare species

• want to ensure waters remain protected and conserved by all users

• educate visitors

what are the advantages of lundy island conservation zone

• protection of rare species

• education of visitors

• supports scientific research

what are the disadvantages of lundy island conservation zone

• restricted fishing- reduction of income

• costly management

• conflict between human land use and conservation

describe the serengeti national park and what they do

• anti-poaching

• breeding and rehabilitation programs

• restoration of native vegetation

• protected area in tanzania