Unit 3 Flashcards
Biodiversity
Is the variety of all life on earth.
Includes genetic diversity, species diversity and habitat diversity.
Factors that affect biodiversity and benefits of biodiversity
Age of area - older areas - higher biodiversity
Environmental stability - earthuaks disturbances
Range of habitats
Benefits
- financial benefits
- invaluable services
- playgroud
-educational opportunities
Species diversity
is the number of different species in a given area taking into account the richness and evenness of the species.
Species diversity in communities is a product of two variables: the number of
species (richness) and their relative proportions (evenness).
Simpson Diversity Index formula and ca
D is the Simpson Diversity Index
N total number of organisms found
n is the number of individuals of a particular species
What does the Simposon Diversity Index allow?
Puts a mathematical value on the diversity of a community which allows comparison of communities over time and space
Genetic diversity and importance
Refers to the variation of genes within the genetic pool of a population of a species it is the means by which that population can adapt to change.
IMP
- Better chance members are reciliense and survive to disease
- Low genetic diversity makes the population more uniform and amplidies disabilities
- frequent extinction
- once lost GD difficult to regain
- wy rely on species for medicine, food..
Habitat diversity
The range of different habitats in an area.
Terrestial biomes - most important abiotic environment for plants: temperature, soil type, precipitation.. A variety of vegetation in an area results in a grater diversity of animals
Marine habitats - transient and changable an abiotcic factors incluse dissolved gasses, land runofff, marine topography, nutrients, salinity, pH, sunlight, temp
Links between habitat diversity, genetic diversity and species divesity
- High habitat diversity = more areas for populations –> greater variation of gene pool
- High habitat diversity = wide range of spaces for animals to adapt –> High species diversity
- High genetic diversity = increased adaptability of species –> higher species biodiversity
- High species diversity of plants –> higher habitat diversity
Evolution
is a gradual change in the genetic character of populations over many generations, achieved largely through the mechanism of natural selection.
Environmental change gives new challenges to species, which drives the evolution of diversity.
There have been major mass extinction events in the geological past.
Causes of evolution
Process of genetic variation
- Mutations (change in DNA) may be beneficial, harmful, neutral
- Natural selection - the gene variatons has survival advantages
Speciation
is the formation of a new species through biological processes.
Relationship between speciation and diversity
Evolution drives speciation and it is commonly dirved by isolation
- Geographic isolation: Populations are physically separated and can no longer interbreed
- Temporal isolation: Populations live their lives at different times of the day and so do not meet to breed.
- Behavioural isolation: They have different mating rituals.
Natural selection occurs through the following mechanism
Within a population of one species, there is genetic diversity, which is called variation.
Due to natural variation (range of genetic diversity). some individuals will be fitter than others.
Fitter individuals have an advantage and will reproduce more succesfully than individuals who are less fit
The offspring of fitter individuals may inherit the genes that give that advantage
Plate techtonics theory
The theory explains the motion of the earth’s lithosphere (outer layer) and the impact that has had on the distribution of the continents
Plate movement has a significant impact on evolution and creates opportunities for biodiversity
The separation and movement of the continents creates new islands and moves the continents into different climatic zones forcing evolutionary change.
The movement creates four types of plate boundaries each associated with different types of activity with varying impacts on biodiversity.
Hotspots and other volcanic activity create new land.
Endemic species
is unique to a particular location and not found elsewhere.
It is important that you understand and are able to explain how climatic variation impacts evolution through natural selection and thus biodiversity.
different areas of the world have very different climates, caused largely by their latitudinal positions.
The only organisms that can survive in an area are those that have evolved and adapted to the temperature, precipitation, and sunlight levels and the seasonal patterns they all show.
So a wide range of climatic zones means evolutionary adaptation and a wide range of organisms = MORE BIODIVERSITY
The range of climates seen on Earth provide diverse habitats, niches and food sources, all of which contribute to evolution through natural selection high biodiversity.
Plate boundaries
Three types
Divergent and convergent have both significant positive and negative impacts on biodiversity.
Convergent: Move together create mountains, volcanoes, land bridges, ocean trenches
divergent: Move apart and create opp for diversificaton
Volcanic activity affects diversity
Creates new habitats and niches both on land and in the oceans. Any new land created by volcanic eruptions is subject to succession as species colonise the area, for example the southern end of the Hawaiian island chain consists of a large active volcano, Kilauea.
Mass extinctions
is a sudden global decrease in the number of species over a relatively short period of time.
Background or normal extinction is the standard rate at which species go extinct.
Ordovician-Silurian mass extinction (440 million years ago): Glaciation caused by falling CO2 levels wiped out over 80% of marine life.
Late Devonian mass extinction (375-360 million years ago): Lasting 500,000 to 25 million years, it remains unclear but wiped out 75% of species, hitting marine life and coral reefs hard.
Permian mass extinction (250 million years ago): “The Great Dying” saw the loss of 96% of species; causes range from catastrophic events to gradual processes.
Triassic-Jurassic mass extinction (200 million years ago): Over 18 million years, around half of known species went extinct, possibly due to climate change, sea level fluctuations, and asteroid impacts.
Cretaceous-Tertiary mass extinction (65 million years ago): An asteroid impact in Yucatan eliminated dinosaurs and perhaps 80% of life, enabling mammals and birds to thrive.
Sixth (Holocene) mass extinction (ongoing): Driven by human activity, it is predicted to exceed 65 million years of species loss by 2065.
Estimating species numbers
Estimates of the total number of species on Earth vary considerably. They are based on mathematical models, which are influenced by classification
issues and a lack of finance for scientific research, resulting in many habitats and groups being significantly under-recorded
Human threats to biodiversity 6
- Population Growth
- there is increasing demand on natural resources which has led to over-exploitation of species, habitat degradation, human introduction of alien species and pollution of the environment - Over explotatition of resources
- Resorces need time to regenearet otherwise, numbers will fall below a threshold level from which they cannot recover. ex overfishing - Habitat degradation
- Forests have often been exploited for construction material, firewood, food and medicines
- land used for settlements, industrial development, grazing, growing crops - Invasive species
- Some of these invasive species have adapted to the new conditions and have gone on to breed successfully. Problems have arisen when they degrade the habitat or out-compete local species for resources such as food. - Pollution
These inputs can degrade the habitat and decrease species diversity. - Climate change
Human activity has increased the amount of greenhouse gases such as carbon dioxide, methane and chlorofluorocarbons in the atmosphere. Overall rise in weather temperatires, change in precipitation. Species unable to adaot
The role of the International Union for Conservaion of Nature (IUCN) Red List
Aims to provide information and analysis on the status, trends and threats to species in order to inform and catalyse action for biodiversity conservation
IUCN Redlist criteria to determine the conservation of species
- Population size: number of mature individuals
- Population size reduction: Loss of indivifuals
- Geographical range: extent of occurance and area of occupancy. Area of occupancy is where species are found normally. The extent of occurrence is the sites the species occupies
4.Number of locations: with thereates, number of locations may decline
- Extent of habitat fragmentation : species may become isolated and not have the critical numbers of mature individuals to survive
- Quality of habitat: contributes to success of species
- Probabilty of extinction
Case study - Extinct species
Tasmanian Tiger
Extinct about 2000 years ago
Carnivorous and had similar characteristics to a dog
Fed on kangaroos, rodents and birds
factos that contributed tho the exintion
- competition from dingoes and fogs
- human hunting
- habitat loss
- population fragmentation
Case study - critically endangered species
Hawksbill Turtle
Lives in tropical rainforests and coral reefs
Omnivorous - alge, sponges, mollucst, fish
Used in traditional medicines, jewlery, symbol of wealth, tourist attractions
Decline in species
- reduced nesting sites
- loss of feeding jabitats
- Ingestion of plastic
- climate chane
- collection of eggs
Case study - improved conservation status
Lears MaCaw
parrots that eats nuts, flowers and maize.
threats:
- capture of parrots - pet trade
- change to grassland habitat
- Grazing of its habitat by livestok
Action taken by CITES and Brazilian law
- monitoring bird habitat
- enforcing legislation
- Protecting palms from livestok
- health monitor of species
- education and awarness
Biological hotspots
More than 1500 endemic plant species and loss of more thann 70% of the vegegation
Role of EVS in conservation of biodiversity
Deep ecologist - Importance of intrinsic value of environment and species. Biorights of all species and habitats. Minimum disturbance and use of ecosystems. (PRESERVE RESOURCES)
Cornucopians - All natural resources can be justifiably used for human benefit. Human ingenuity and technological developments will find solutions to any future environmental problem. Any deficits can be overcome with substitutes. Exploitation of resources should only be limited by scientific, technological developments or by the economic cost. (RESOURCE EXPLOITATION)
Environmemntal managers - People should manage resources sustainably with concept of sustainable development central to all activities. Policies and regulations should be used to mange natural resources and restrict environmental damage. Economic and educational tools should be used to encourage sustainable development. Problems should be solved though community participation. (SUSTAINABLE DEVELOPMENT)
Reasons to conserve biodiveriwsty
Utilitarian value
- consumtive use - food, medicine
- non consumtpive - aesthetic, recreational
- services
- future value
Non-utilitarian value
- intrinstic value (biorights)
- Knowing experies exists
NON Govermental Organizations
are non-profit, voluntary organisations usually funded by charitable donations and membership fees.
NGOs often try to change policies, legislation and behavior at the individual level in a variety of ways:
- Lobby goverments
- Media use
-Direct action
- education awareness
- reaserch
- manage threatened habitats
- work together with goverments businesses communities
- monitor activity
Intergovermental organizations
EX.
The United Nations Environment Programme (UNEP)
Food and Agricultural Organizations (FAO)
Intergovernmental Panel on Climate Change (IPCC)
Key features
- ability to make decisions at international level
- provision of lastest information
- driect media communication
- long and lengthy decision making process
- politially driven decisions
- bureaucratic iamage - little understanding and connection with local communities
International conventions on biodiversity
Conservation approaches include habitat conservation, species-based conservation and a mixed approach.
CITES Convention on International Trade in Endangered Species of Wild Fauna and Flora
Ratified by more than 180 nations.
Aims to ensure that international trade does not threaten survival of the species.
It has three lists of controlled fauna and flora:
Appendix I contains species threatened with extinction and trade is only allowed under exceptional circumstances.
Appendix II contains species at potential risk from international trade; a permit is required for all trade in these species.
Appendix III contains species protected in one or more countries; they are not under global threat but are of concern in the countries which have nominated them for protection. Trade in appendix III species is regulated by use of permits and national laws.
Strengths
Restricts trade which threatens species becoming extinct.
Encourages education about endangered species.
Increases awareness of endangered species and changes perception about their use e.g. as pets or ornaments.
Can stimulate funding into research and conservation activities.
Weaknesses
Participation is voluntary, not mandatory.
Focuses on preservation of species and not sustainable use. If people are allowed to benefit from the wildlife (for example, through tourism revenue or trade of natural income), they have an incentive to protect them.
Focuses on species conservation, whereas the main threat to biodiversity is habitat loss.
Effective enforcement can be difficult.
Trade is often driven underground (illegal/black market).
Many countries with limited resources have other national priorit
Key stone species VS Umbrella Species
Keystone - These species interact through the food web with other species in the community
if lost could lead to the demise of other species.
Conserving a keystone species helps to protect the integrity of the community.
Umbrella - oftern large species requiring large habitat areas. Protecting the habitat also protects the spcies. The Giant panda is an umbrella species
In situ conservation
To prevent a species becoming extinct, the reasons for species loss need to be addressed.
- Lear’s MaCaw is restricted by CITES (discussed below) and national law in Brazil. Monitoring of illegal activity coupled with enforcement and working with local communities has led to improvements in bird numbers in their natural habitats.
- CITES
Ex situ conservation
This can be a long and expensive process in which organisms are taken out of their natural habitat in order to be conserved
Adv
ncrease numbers and decrease risk of extinction.
Opportunity to learn more about the species biology and behaviour.
Use of zoos, aquariums and botanical gardens to educate public about the species and gain financial and political support.
Genetic pool can be enhanced (including use of reproductive technology eg artificial insemination).
Provides a temporary safe place to live while habitats are being restored.
DISV
Require resources including finances to undertake ex-situ conservation.
Does not address causes of habitat loss.
Genetic pool may be small, not representative of original populations and could result in inbreeding problems.
They may not be able to survive in the wild if re-introduced. Need to develop hunting skills and migratory patterns which are difficult to learn in captivity.
Captivity can be detrimental to their health and also lead to aggressive behaviour.
They may be susceptible to disease when concentrated in a small area.
Breeding in captivity can be difficult for some species e.g. the giant panda has a poor success rate of breeding in captivity.
There are ethical concerns about keeping animals in captivity.
Reasons for designating a protected area
A clearly defined geographical space, recognised, dedicated and managed, to achieve the long term conservation of nature with associated ecosystem services and cultural values.
Types: National parkes, nature reserves, wilderness areas.
Reasons
- level of biodiversity eg. hotspots
-presence of endemic spcies
-Rarity of habitat type
-Geological features
- Educational value / scientific
- Cultural religious
Edge effect
Increase sunlight, temperature, lowers humidity, result in an increase of air movement
Change in abiotic factors affect habitat conditions and threaten speces + preduation and huntinf
What is the ideal shape for a conservation area and ideal location
optimal shape is a circle because it has a minimum edge to area ratio
f reserves are near to human settlements, large animals may venture out of the reserve and raid crops and even attack people
Characteristics of a succesfull protected area
Community support and involvement
Adequate funding
Increasing understanding through reasech
effective managemnet plan
legislatin and efectve enforecment
legal ststus
variaety of biodiversity
Protected area case study
Manu national park - Madre de Dios
Aims to conserve biodiversity in souther rainforest of peru
- Hotspot
Success
- reasech conducted
- educational programes
- visitors many per year
- recogized worldwide for diversity
Threats
- roads
- umbrella and flagshp species like jaguars and pumas
- Giant otter no longer due to effrt
3 zones in designing a protected area
Core area: the pristine natural environment under protection.
Buffer zone: found between the core area and transition zone. To minimise any harm in this area, use is limited e.g. for scientific research, training and education. This area acts as a barrier to protect the core area from human activities in the transition zone.
Transition zone: where there is sustainable use of natural resources. This area can be affected by human activities outside the transition zone such as intensive farming.
Evaluate the value of conecting reserves
Linking the reserves has various advantages:
It can allow migration between reserves and reduce isolation of the population.
Immigration from other reserves can increase the gene pool in the reserve.
It can allow for seasonal migration.
There are also some disadvantages associated with wildlife corridors connecting reserves:
Increase spread of disease from one reserve to another.
Increase threat from invasive species.
Increase threat from predators and hunters.
Human influences in protected areas
- noise distrurbances
- light pollution
- large animals can escape and raid crops or attack people
