6GEO3 Unit 3 Contested PlanetTopic 3: Biodiversity under Threat

What is this topic about?

• Biodiversity under Threat is the third of the ‘resources’ topics

• It examines the nature of biological resources, essentially plants and animals, and how people use and conserve them

• The earth’s biosphere represents a critical part of the planet as a life support system

• How humans act towards the biosphere reveals a great deal about their priorities, attitudes and understanding.

Biodiversity’s future?An endangered Kangaroo in San

Diego Zoo

1.Defining biodiversity2. Biodiversity threats3. Managing biodiversity

CONTENTS

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1. Defining biodiversity • Biodiversity can be defined in a

number of ways • High levels of biodiversity might be

seen as ‘healthy’ because narrow genetic diversity means species are vulnerable to disease

• Species diversity is the most commonly used definition.

Bio…?

•Biodiversity – the variety of genes, species and ecosystems in an area. •Biosphere – the thin veneer of living material on the planet’s surface•Biome – a global scale ecosystem e.g. tropical forest •Biomass - the total weight of living matter per unit area (dry)

Influences on biodiversity• Biodiversity is high on large, high, tropical (low latitude) islands –

Madagascar, Sumatra and Java are good examples

Lack of factors to limit growth: lots of light,

warmth and rain promote growth

Altitude produces a range of ecological zones, each with its

own species

Islands are isolated, so evolution goes its own

way producing new unique species and

varieties; this is called endemism.

The isolation of islands limits human influence – at least until recently

Decay and nutrient cycling

are rapid in tropical soils

Large areas can support large numbers of species in complex

food chains, with space for top carnivores.

Today, humans factors are important – how protected is an area? Does poverty

force people to destroy ecosystems? How widespread is deforestation and

the need for new farmland? How fast is population growing? Do people care

about biodiversity?

Global biodiversity

• Due to several 100 years of intense human activity the global pattern of biodiversity is no longer ‘natural’.

• Humans can have both positive and negative influences on biodiversity

• Norman Myers coined the terms ‘biodiversity hotspot’

• Hotspots are areas with:High species richnessHigh levels of endemism (uniqueness)Facing severe human threats • Biodiversity hotspots (see map, next

slide) are often tropical areas, islands and highlands –but also areas in the developing world where poverty leads to ecosystem destruction.

Biodiversity hotspots

Combined area covers only 2.3% of the Earth's land surface. Each hotspot has already lost at least 70% of its natural vegetation. Over 50% of the world’s plant

species and 42% of all terrestrial vertebrate species are endemic to the 34 biodiversity hotspots.

The value of ecosystems • Ecosystems have value• In some cases, a financial value can be

calculated – income from timber or tourism• Much of the value of ecosystems cannot easily

be calculated in monetary terms• Healthy, biodiverse ecosystems are essential

for maintaining human wellbeing

You need to be able to assess the value of ecosystem services

with reference to one global ecosystem (biome) e.g. coral

reef, tropical forests, or temperate grasslands etc.

2. Biodiversity threats

• Biodiveristy hotspots are by definition areas which are under threat

• In some areas, threats are so great that extinction is occurring

• These areas can be seen on the map to the right (compare to map on slide 7)

• Cold environments tend to be fragile and lack resilience

• Small islands have low populations of species, and have high endemism

• Forests are simply too resource rich to be left alone in many cases.

Global threats

• Globally there are a number of trends which threaten ecosystems and biodiversity

Local threats

• In small scale areas, local threats can be numerous and represent a severe threat to ecosystems and biodiversity.

Localised deforestation; clearance for farming

and urbanisation

Tourism development; trampling, erosion;

urbanisation and associated pollution; increased risk of

wildfires

Overfishing and harmful forms of fishing e.g.

dynamite and cyanide

Siltation from runoff; increased risk of alien

invasive species

Runoff from farms and urban areas;

eutrophication and heavy metals in rivers, lakes and

seas

Mining, ranching and overgrazing, road building

leading to ecosystem fragmentation

Ecosystem processes

• Functioning ecosystems have a continual flow of nutrients (top) and energy (bottom) through them

• These systems are self-regulating, but prone to human disruption:

Deforestation or over fishing depletes the biomass store in the nutrient cycle

Climate change may affect precipitation, runoff, decay rate and weathering rate

Alien species can disrupt the food web, changing the balance of predators and prey

Eutrophication drastically increases available nutrients

Alien invasive species

• Our globalised world has increased the threat from alien invasive species

• These are species which move out of their natural habitat and colonise new areas, as a result of human activity

• Such species don’t move because they want to find a better place to live!

• Some aliens are introduced deliberately, perhaps as a food source, predator or ornamental species, but then escape into the wild and have unintended consequences

• Other aliens are accidental introductions

Successful invaders tend to be:Capable of rapid reproduction

Able to disperseRapid growing

Tolerate a range of environmental conditions

Able to eat a wide range of foods

Species such as rats, goats, the Chinese Mitten crab and Zebra Mussel are successful,

and highly destructive, aliens

Ecosystem destruction

• Pristine ecosystems are rare today• Highly developed countries tend

to have few of them, although they may use their wealth to protect, conserve and restore ecosystems

• Wealth, and leisure time, tend to mean people have positive attitudes to the environment

• In NICs and RICs (see graph) threats to ecosystems tend to be severe, as ecosystems are used as resources and there is limited money for conservation

• In less developed countries, yet to industrialise, ecosystem may not be exploited yet – but for how long?

3. Managing biodiversity

• Given that 6.5 billion humans cannot stop ‘using’ ecosystems, is there are safe way to use them?

• A certain level of use (yield) is sustainable – be it logging, fishing, hunting etc.

• This level is the Maximum Sustainable Yield for a species / ecosystem – the level at which utilisation by humans does not lead to long term decline in species numbers

• In reality, taking the MSY leaves no room for error (or climate change, disease etc)

• The Optimum Yield is lower, and safer in terms of long term sustainability.

Players• Different players have

conflicting views on biodiversity and ecosystems

• One player may have quite complex views e.g. wanting to protect the rainforest but still use its products

• Some players view ecosystems as a resource to be exploited, but this could be out of necessity (subsistence) as well as for profit (TNCs)

• Other players may be much more conservation minded and focus on the ecological and aesthetic value of biodiversity

“First, get rid of them tree, then its

perfect cattle country”

“What a great photo, but the car parking could be better”

“What do we want? National

Park! When do we want it? Now!”

“Keep the forest, we’ll build the

hotel on this side of the lake”

Organisations and campaigners

IGOs Individuals NGOs Government

UNESCO, UNEP Sting, Al Gore, David Attenborough

Greenpeace, WWF

UK (local and national)

Different arms of the UN are responsible for CITES, World Heritage Sites and helped with the Millennium Ecosystem Assessment.Global treaties, scientific research and monitoring are important aspects of their work.

Certain individual campaigners have the ability to reach a global audience and push for change.

Some NGOs, like WWF or The Nature Conservancy help manage conserved areas.Other like Greenpeace, campaign to keep issues in the media, and lobby governments and IGOs

Government policy is crucial to ecosystems conservation and preservation of biodiversity. Governments implement and police treaties like CITES and set up and run National Parks and other conservation areas.

What to conserve?

• There is not, and never will be, a limitless pot of money for conservation.• Decisions have to be taken about what should be conserved , but these

decisions are difficult to make

ICONIC speciesRaising money for Pandas, Tigers and Chimps is relatively easy, but how important are they at a global level?

KEYSTONE speciesSpecies such as Bees, the pollinators of numerous plants, are crucial but hard to ‘sell’ to a wary public

HOTSPOTSHotspots are clearly under threat and very biodiverse; they would yield a lot of conversation per $ spent, but many areas (like the Arctic) are not biodiverse enough to qualify

ECOREGIONSEcoregions are large areas, like Amazonia; conserving them would achieve a great deal, but would be expensive and difficult to police and monitor. Ecoregions do fit the ‘Single Large’ rather than ‘several small’ model which would allow species to shift due to climate change.

Management strategies • Ecosystems and biodiversity can be managed in a range of different

ways • There is a spectrum of different management strategies• Some are sustainable as they balance ecological and human needs

Scientific Preserve with no

access for public

Wildlife Parks and

Nature Reserves

National Parks;

extractive reserves

Conservation and

Development areas

‘Paper Parks’

Zoos and Gene Banks

Sustainable Management

Biosphere reserves

• One of the most common form of conservation management is the UNESCO Biosphere reserve model

• Biosphere reserves use the principle of zoning to conserve core ecological areas, whilst allowing some economic development – such as eco-tourism or managed hunting or logging

• Educating local people to conserve resources for future generations is important

• Biosphere reserves usually have scientific research and monitoring activities too

• Famous locations such as the Galapagos and Komodo NP use elements of the biosphere reserve model

Biodiversity futures• 2010 is the UN International Year of Biodiversity • This alone shows how important biodiversity is to the

planet’s future. • UNEPs GEO-4 Project (2007) identifies 4 possible futures for

biodiversity and ecosystems (below)• There are some difficult choices to be made!

Markets First Profit driven future, playing lip-service to sustainability. Continued degradation of biodiversity

Policy FirstA greater balance between human and ecological wellbeing, but humans are put first by short-termist policymakers and ecosystems are protected when possible and expedient

Security First ‘Me First’ – the focus is on maintaining the wealth of the few in a very unequal world; IGOs like the UN are viewed with suspicion; the environment is there to be exploited.

Sustainability First Equal weight is given to human and ecological wellbeing , and thinking is long-term to gradually recover lost ecological ground