Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Salit Kark

Department of Evolution, Systematics and EcologyThe Silberman Institute of Life Sciences

The Hebrew University of Jerusalem

Conservation Biology (Ecology)Lecture 2Oct 2009

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

What is Biodiversity?What is Biodiversity?"...the diversity within species, between species and of "...the diversity within species, between species and of

ecosystems” (UN Convention on Biological Diversity 1992)ecosystems” (UN Convention on Biological Diversity 1992)

The within species component has been defined as “the The within species component has been defined as “the frequency and diversity of different genes and/or genomes...” frequency and diversity of different genes and/or genomes...” (IUCN 1993)(IUCN 1993)

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

What is Biodiversity?

“the millions of plants, animals, and microorganisms, genes they contain, and the intricate ecosystems they help build into the living environment” (World Wildlife Fund, 1989)

“the variety of life on Earth at all its levels, from genes to ecosystems, and the ecological and evolutionary processes that sustain it.” (Gaston 1996)

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

How many species are there?

Which groups do they belong to?

Why is it so unevenly distributed?

Patterns of biodiversityPatterns of biodiversity

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Where is it found?

What are the main correlates?

Patterns of biodiversityPatterns of biodiversity

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Conservation International’s hotspots

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Global environmental changesClimate change

Habitat fragmentation and destruction

Invasion by alien species

Major threat to biodiversity, to the functioning of ecological systems and to the services provided to humanity by nature (threshold?)

Opportunity to address research questions central to conservation ecology (“grand natural experiment”)

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Human related factors shaping biodiversity:

We will deal with some of these in more detail during our course: Fragmentation and habitat destruction Urbanization and changes in land use Agriculture (type, matrix) Introduced species Pollution Climate changes (changes in climatic means and extremes, competition, communities, distributions ranges…)

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Genetic diversity

Number of populations

Number of species

Number of endemic and rare species

Ecosystems and their services

Biodiversity decline:

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Current extinction rates are likely occurring at 100 to 1000 times the normal background extinction rates. If these continue over the centuries, there will be extinction levels as in the Big Five.

Biodiversity and extinction today

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Source: World Conservation Monitoring Centre, "Global Biodiversity" Chapman & Hall, London, 1992).

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Ecologists estimate that we have lost hundreds of thousands of species in the past 50 years.

Experts predict that if present trends continue, we are likely to lose half of all living species within the next century.

Certain groups and regions are disappearing faster:

Almost half of all plant species could be facing extinction (Science, Nov 2002)

Tropical forests, Mediterranean regions…

One of the differences from past extinctions is the rapid pace of today's extinctions.

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Many documented extinctions from the recent past have occurred on islands (e.g. New Zealand, Hawaii and Mauritius)

but some prominent continental exceptions (such as passenger pigeons, some species of buffalo and mastodon)

Local Extinctions on Islands: Human Impact Over History

dodoIvory-billed woodpecker

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

The last captive specimen of the marsupial tiger died in a Tasmanian zoo in 1936. No living specimen has been verified since, but sporadic reports persist in Tasmania, Victoria, and Western Australia.

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

20% of birds in Pacific region gone due to human colonization of islands

60 endemic species on Hawaiian islands went extinct 1,500 yrs ago after settlers arrived

44 species (including flightless moas) went extinct in New Zealand after Polynesian settlers arrived.

Evidence over past 2,000 years shows Evidence over past 2,000 years shows major human effects:major human effects:

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Tropical Forests Tropical forests occupy only 7% of the land

area on Earth but contain 50% of the species

Human impact is more recent in tropics

currently have highest population growth rates

Highest rates of habitat loss

Africa and Americas 1980-1990: 0.7% tropical forest lost per year

Asian tropical forest worse: 1.1% loss per year

Amazon forest largest continuous forest on Earth. Forest destruction rapid and large scale.

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

How can we calculate the rate of species extinctions from habitat fragments?

There have been only a few such estimates, but combining the rate of habitat loss, the species-area relationship and survivorship curves gives a crude extinction curve.

Biodiversity: Extinction by numbers

Stuart Pimm and Peter Raven 2000. Nature 403,843-5

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

?יש הכחדות בישראל...

?גנים

מינים

מערכות

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

מהם , מיני צמחים שנכחדו בישראל39כיום ידוע על . נכחדו עד אמצע שנות השישים69%

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.לחשיבה ומנהיגות סביבתית ,מכון ירושלים לחקר ישראל והוצאת בבל

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

רון פרומקין ,אבי שמידע ,יובל ספיר ,אורי פרגמן –ספיר ונעם לויןצמחים נכחדים בישראל

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Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Why conserve biodiversity?

The value of biodiversity

Indirect:

Water and soil protection, climate regulation…

Existence (inherent), ethical values

Direct:

Economic, resources

?למה לשמור

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

The value of biodiversity

Source: The Economic Value of BiodiversityIUCN —The World Conservation Union

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

The value of biodiversity (Meffe 1997)

Category Instrumental value

Examples

Goods Food, fuel, fiber, med, cosmetic

Services Pollination, water purification, carbon fixation

Information Genetic engineering, applied biology, biotechnology, pure science

Psycho-spiritual Aesthetic beauty, religious awe, scientific knowledge

Intrinsic value

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

The value of biodiversity – forest example

Source: The Economic Value Of Biodiversity

IUCN —The World Conservation Union

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Why conserve biodiversity?

The value of biodiversity

Indirect:

Water and soil protection, climate regulation…

Existence (inherent), ethical values

Direct:

Economic, resources

Salit Kark, Conservation Biology, Hebrew University, Lecture 2

Some ethical arguments for preserving biodiversity (Primack 2002):

Each species has a right to existEach species has a right to exist

Species are interdependent (The Rivet hypothesis)Species are interdependent (The Rivet hypothesis)

We have responsibility as stewardsWe have responsibility as stewards

Responsibility for future generationsResponsibility for future generations

and more…and more…