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Conservation Biology (Ecology)
Lecture 2
Oct 2009
Salit Kark
Department of Evolution, Systematics and Ecology
The Silberman Institute of Life Sciences
The Hebrew University of Jerusalem
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
What is Biodiversity?
"...the diversity within species, between species and of
ecosystems” (UN Convention on Biological Diversity 1992)
The within species component has been defined as “the
frequency and diversity of different genes and/or genomes...”
(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
Patterns of biodiversity
How many species are there?
Which groups do they belong to?
Why is it so unevenly distributed?
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Patterns of biodiversity
Where is it found?
What are the main correlates?
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Conservation International’s
hotspots
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Global environmental changes
Climate 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
Biodiversity decline:
Genetic diversity
Number of populations
Number of species
Number of endemic and rare species
Ecosystems and their services
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Biodiversity and extinction today
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.
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
One of the differences from past extinctions is the rapid
pace of today's extinctions.
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…
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Local Extinctions on Islands:
Human Impact Over History
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)
dodo
Ivory-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
Evidence over past 2,000 years shows
major human effects:
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.
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
Biodiversity: Extinction by numbers
Stuart Pimm and Peter Raven 2000. Nature 403,843-5
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 speciesarea relationship and survivorship curves gives
a crude extinction curve.
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
?‫יש הכחדות בישראל‬...
?‫גנים‬
‫מינים‬
‫מערכות‬
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
‫כיום ידוע על ‪ 39‬מיני צמחים שנכחדו בישראל‪ ,‬מהם‬
‫‪ 69%‬נכחדו עד אמצע שנות השישים‪.‬‬
‫צמחים נכחדים בישראל רון פרומקין ‪,‬אבי שמידע ‪,‬יובל ספיר ‪,‬אורי פרגמן –ספיר ונעם לוין‬
‫מתוך ‪:‬פרומקין ‪,‬ר '‪,‬חנין ‪,‬ד 'ואידלמן ‪,‬ע '(עורכים) ‪ 2004.‬סימני חיים‪ ,‬מרכז השל‬
‫לחשיבה ומנהיגות סביבתית ‪,‬מכון ירושלים לחקר ישראל והוצאת בבל‪.‬‬
‫‪Salit Kark, Conservation Biology, Hebrew University, Lecture 2‬‬
‫מתוך ‪:‬פרומקין ‪,‬ר '‪,‬חנין ‪,‬ד 'ואידלמן ‪,‬ע '(עורכים) ‪ 2004.‬סימני חיים‪ ,‬מרכז השל‬
‫לחשיבה ומנהיגות סביבתית ‪,‬מכון ירושלים לחקר ישראל והוצאת בבל‪.‬‬
‫צמחים נכחדים בישראל רון פרומקין ‪,‬אבי שמידע ‪,‬יובל ספיר ‪,‬אורי פרגמן –ספיר ונעם לוין‬
‫‪Salit Kark, Conservation Biology, Hebrew University, Lecture 2‬‬
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
?‫למה לשמור‬
Why conserve biodiversity?
The value of biodiversity
Direct:
Economic, resources
Indirect:
Water and soil protection, climate regulation…
Existence (inherent), ethical values
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
The value of biodiversity
Source: The Economic Value of Biodiversity
IUCN —The World Conservation Union
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
The value of biodiversity (Meffe 1997)
Category
Instrumental value
Goods
Examples
Services
Pollination, water purification,
carbon fixation
Genetic engineering, applied
biology, biotechnology,
pure science
Aesthetic beauty, religious awe,
scientific knowledge
Information
Psycho-spiritual
Food, fuel, fiber, med, cosmetic
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
Direct:
Economic, resources
Indirect:
Water and soil protection, climate regulation…
Existence (inherent), ethical values
Salit Kark, Conservation Biology, Hebrew University, Lecture 2
Some ethical arguments for preserving
biodiversity (Primack 2002):
 Each species has a right to exist
 Species are interdependent (The Rivet hypothesis)
 We have responsibility as stewards
 Responsibility for future generations
 and more…
Salit Kark, Conservation Biology, Hebrew University, Lecture 2