Download Ecosystem services

ECONOMIC ASPECTS ON THE
CONSERVATION OF
BIOLOGICAL DIVERSITY
Göran Bostedt
Dept. Of Forest Economics
SLU
A comparison between conservation
of biodiversity and climate change
• UN Conference on Environment and
Development (UNCED) in 1992, the so
called Earth Summit, produced two binding
conventions:
– United Nations Framework Convention on Climate
Change, the so called climate convention.
– UN Convention on Biological Diversity, the so called
biodiversity convention.
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The story of two conventions...
• The climate convention: on the big stage in
research and politics.
– Led to the so called Kyoto protocol in 1997,
emissions of greenhouse gases should be
reduced
– Summit in Copenhagen 2009 aiming to find a
successor to the Kyoto protocol failed.
– UN’s climate panel, IPCC, aims to give
scientific support to the political negotiations.
that
• Biodiversitety convention: the small stage
– Led to the Cartagena protocol in 2003, which among other
things aims at protecting biodiversity against modern
biotechnology.
– Led 2005 to the Millennium Ecosystem Assessment, an
attempt at giving support to political negotiations, in a similar
way as the IPCC.
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The story of two conventions...
• The conservation of biological diversity is
seen as extremely important in the scientific
community.
– “The central environmental challenge of our time is
embodied in the staggering losses, both recent and
projected of biological diversity at all levels, from the
smallest organisms to charismatic large animals and
towering trees.”
Levin (1999):
Fragile Dominion: Complexity and the Commons
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The story of two conventions...
• The view that conservation of biodiversity is a
central challenge is not shared by policy
makers and the general public.
• Why the difference?
• Why has the climate change issue received
the political attention that conservation of
biodiversity is lacking?
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The story of two conventions...
• Two aspects can help to explain the difference:
•
The link from human activities to environmental changes.
•
The link from environmental changes to human welfare.
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Climate change
• Link from human activities to environmental
changes:
• Emissions of greenhouse gases cause increasing atmospheric
concentration of these gases – this is uncontroversial.
• Increasing concentration of greehouse gases leads to climate
change - in principle uncontroversial, but the question is how fast.
• Link from environmental changes to human welfare:
• List is long: Sea level changes
• Increased storm intensity
• Chnages in rainfall, with drought in some places
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Biodiversity
• Link from human activities to environmental
changes:
• Clear and perceivable evidence – more on this later.
• Link from environmental changes to human
welfare:
• Less obvious, so far – how are we affected when a species we
never heard about goes extinct in the Amazon due to deforestation?
They're running out of rhinos - what do I care?
Let's hear it for the dolphin - let's hear it for the trees
Ain't running out of nothing in my deep freeze
It's casual entertaining - we aim to please
At my parties
(Dire Straits)
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Milllenium Ecosystem Assessment 2005
• Ecosystems and biodiversity are
essential for human welfare.
• Ecosystem services is the central
organising principle.
• Contains a comprehensive account
of the status and trends when it comes to
biodiversity, in particular when it comes to habitat
changes.
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Factors behind the loss of biodiversity
•
•
•
•
•
Habitat destruction
Invasive species
Pollution (including Climate Change)
Population
Overharvesting
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Human activities and loss of
biodiversity
• How can we claim to have a ”biodiversity crisis” when we
today know about more species than ever before in the
history of mankind?
• To calculate extinction rates:
• Species-area curves: n = c * Az where n is the number of species and A is the
area of a certain region. The rate of change when A is reduced is then z.
• The value of the parameter z has been estimated for areas like islands.
• If z = 0,25 the rate of change in n is 25 times higher than the rate of change in
A.
• If we know the rate of change in A – e.g. the deforestation rate in the Amazon,
we can say something about the rate of loss in biodiversity.
• Large uncertainties in this method.
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Loss of biodiversity and human
welfare
• In the Millennium Ecosystem Assessment this link is largely
missing.
• An inconvenient truth:
• Rich countries have relatively low biodiversity (Europe, Japan, USA).
• Poor tropical countries have high biodiversity (Afrika, Asia, Latin Amerika).
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Plants in some countries
• Developing countries
Vascular plants Land area (km2)
• Brasil
56,215
8,456,510
•Malaysia
15,500
328,550
•Costa Rica
12,119
50,660
• USA
19,473
9,158,960
• Japan
5,565
374,744
• UK
1,623
241,590
• OECD-countries
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Loss of biodiversity and human
welfare
• Direct benefits:
• Consumptive benefits: Harvest for food, fibres, medicin, etc.
• Non-comsumptive benefits: Animal watching, ecoturism
• Indirect benefits:
• Ecosystem services: Nutrient circulation, purification of water, climate
stabilisation
• Non-use benefits:
• Existence benefits
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Biodiversity and economics –
issues for the economist
• What are the consquences of biodiversity loss and what are
the consequences of conservation? (costs and benefits)
• Which policy measures can be taken and which ones should
be taken? (management and policy)
• Tools of the economist:
•Cost-efficiency analysis
•Cost-benefit analysis
•Analys of incentives and institutions
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What is biodiversity?
-Species diversity
-Genetic diversity
-Eco system diversity
Noahs ark- problem –
Maximizing genetic diversity (Weitzman, 1998)
 The problem:
n
max
V  D( a)   ci ai
i 1
V = Net benefit
D(a) = Diversity of the set a of conserved species Sveriges lantbruksuniversitet
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ci = Cost of conserving species i
How do we measure D(a), the diversity
of the set of conserved species?
• The easiest way is just the number of conserved species –
species richness.
• Species richness is probably the most common measure of
biological diversity.
• Ecologists are quick to point out that there are more
important aspects than species richness.
• Why care about species richness?
• Species richness is connected to productivity, measured as
biomass/area.
• Species richness is important for bioprospecting Sveriges
and gives
greater
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resilience.
Beyond species richness – taking uniqueness into
account
* Genetisk diversitetsmått kan baseras på evolutionära träd
• One can argue that species
without close relatives should
be prioritized: uniqueness is
valuable
Figur 6.3 Släktträd för hominoider (från Weitzman, 1992)
Diversitetsmått baserat på evolutionärt träd
Art
Antal noder
 noder
Människa
4
17/4 = 4,25
Chimpans
4
17/4 = 4,25
Gorilla
3
17/3 = 5,67
Orangutang
2
17/2 = 8,5
Gibbon
2
17/2 = 8,5
Siamang
2
17/2 = 8,5
Summa
17
39,67
noderi
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distance, for instance in DNA
*Applying Weitzman’s
measure on cranes (from
Weitzman,
1993):
* Weitzman's diversity
measure:
Pairwise distances
A-B: 3
A-C: 1
A-D: 4
B-C: 4
B-D: 4
C-D: 5
Nearest neighbour
A-B + C + D = 8
A-B + D + C = 8
A-C + B + D = 8
A-C + D + B = 8
A-D + C + B = 8
A-D + B + C = 8
B-C + A + D = 9
B-C + D + A = 9
B-D + C + A = 9
B-D + A + C = 8
C-D + A + B = 9
C-D + B + A = 10
* The diversity of the set {A, B, C, D} = 10
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The crane family
Species
Applying Weitzman’s measure on cranes (from
Weitzman, 1993):
Latin name
Geographical area
Probability of extinction
Black crowned crane
Balearica pavonina
Central Africa
0,19
Grey crowned crane
Balearica regulorum
Souteast Africa
0,06
Demoiselle crane
Anthropoides virgo
Central Asia
0,02
Blue crane
Anthropoides paradisea
Southern Africa
0,1
Wattled crane
Bugeranus carunculatus
Southeast Africa
0,23
Siberian crane
Grus leucogeranus
Asia
0,35
Sandhill crane
Grus canadensis
North America
0,01
Saurs crane
Grus antigone
Southeast Asia
0,05
Brolga crane
Grus rubicunda
Australia
0,04
White-naped crane
Grus vipio
East Asia
0,21
Eurasian crane
Grus grus
Europe, Asia
0,02
Hooded crane
Grus monachus
East Asia
0,17
Whooping crane
Grus americana
North America
0,35
Black-necked crane
Grus nigricollis
Himalaya
0,16
Japanese crane
Grus japonesis
East Asia
0,29
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*Bevarandediagnostik för tranfamiljen:
Species
Black crowned
Crane (Africa)
Grey crowned
Crane (Africa)
Demoiselle crane
(Asia)
Blue crane
(Africa)
Wattled crane
(Africa)
Siberian crane
(Asia)
Sandhill crane
(North America)
Saurus crane
(Asia)
Brolga crane
(Australia)
White-naped
Crane (Asia)
Eurasian crane
(Eurasia)
Hooded crane
(Asia)
Whopping crane
(North America)
Black-necked
Crane (Asia)
Red-crowned
Crane (Asia)
Sum
Probability of
Extinction
in
years
Marginal diversity
50
Elasticity of diversity
(% increase in
diversity from 1%
decrease in probability
of extinction)
11.3
0.19
8.7
0.06
14.1
5.8
0.02
7.0
0.9
0.10
4.8
3.3
0.23
7.8
12.3
0.35
10.3
24.6
0.01
11.1
0.8
0.05
4.7
1.6
0.04
6.5
1.8
0.21
9.2
13.1
0.02
1.3
0.2
0.17
1.4
1.6
0.35
4.5
10.7
0.16
5.8
6.3
0.29
2.9
5.7
100
100
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Some analytical conclusions:
 Compare the Sandhill crane and the Whopping crane (both
North American species). Although the marginal diversity of
the Sandhill crane is larger, a dollar is better placed on the
Whopping crane since it is more endangered.
 The Siberian crane has very high elasticity of diversity, and
therefore very high conservation potential. Combines
uniqueness with high probability of extinction.
 Note that the above table gives no information about the
marginal cost of decreasing the extinction probability – a
necessary piece of information to complete an economic
analysis.
 Today, instead of making a systematic trade-off between
uniqueness and extinction risk, we simply wait until a species is
on the brink of extinction and then decide to save it, almost
regardless of the cost.
 It makes sense to look hard at indicators such as expected
diversity gain per conservation dollar.
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Conserving species for genetic prospecting
*A commong argument is that biodiversity is important as a source for future
medical drugs – genetic prospecting.
*In USA almost 25% of all prescribed medicin contain active ingredienses from
plants.
*As a source of clues in agricultural and medical research and certain other areas
natural organisms are very hard to replace. In this sense there is simply no
substitute for biodiversity as a wholes.
*However, the decision is usually marginal – should a marginal hectare of rain
forest be cut down or conserved for genetic prospecting? In such a situation it is
not the huge value of all biodiversity in the tropics that counts, but the benefits
and cost for genetic propecting on the margin.
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*The expected value of preserving a marginal hectare
for genetic prospecting depends on:
1)
2)
The expected value of the medical drug
The probability that the source of the drug is in
that marginal hectare.
Even if 1) is high the probability in 2) is very low
unless the number if alternative hectares of rain
forest are low. A variant of the ”water-diamond
paradox”.
Conclusion: This type of argument doesn’t hold up,
other benefits are more important on the margin, like
the benefits of ecosystem services and existence
values.
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Ecosystem services
• In the Millennium Ecosystem Assessment ecosystem services
are devided into four different categories: supporting, regulating,
cultural och providing.
• Supporting (understödjande): ecosystem functions that serve as a kind of base and are
essential for other functions. Can be nutrient and water circulation.
• Regulating (reglerande): more specific functions, e.g. pollination, air and water
purification.
• Cultural (kulturtjänster): all use for emotional wellbeing, e.g. estetic and recreational
values.
• Providing (tillgodoseende): the most obvious ecosystem services, like food and raw
materials, which become goods.
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A framework for valuing ecosystem
services
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Three challenges in valuing
ecosystem services
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Challenge 1
• To understand the ecological system and how it contributes to
goods and services that benefits humans.
• To understand how changes in the ecosystem leads to
changes in the production of these goods and services.
• The ”ecological production function”.
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Challenge 2
• To understand the value of the goods and services that the
ecosystem produces.
• To understand the distributional effects – who gets the
ecosystem services?
• The ”value of ecosystem services”.
• Some have market prices, but many have not.
• Today few non-market priced ecosystem services have been
valued.
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Challenge 3
• An integrated analysis – to combine ecology (and other
natural sciences) with economics and other social sciences)
in an integrated analysis.
• To convert this analysis to policy recommendations.
• Much of this research remains to be done.
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Conservation strategies
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Conservation strategies
• Assume we have decided on a goal and we have an
operational definition of this goal.
• How can we:
• Maximize the goal fulfillment given limited resources
(cost-efficiency analysis.
• Reach a socially efficient outcome (CBA).
• Conservation strategies can imply:
• Land-use changes
• Control of invasive speciesKontroll av invasiva arter
• Harvest policies
• Emission control
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Cost-efficient conservation strategies
• Is focused on habitat conservation through the creation of
reservations/protected areas.
• More known as:
THE RESERVE SITE SELECTION PROBLEM
(RSSP)
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*RSSP is based on the idea that the only way to conserve
biodiversity is to establish protected areas.
*The baseline assumption is that today’s reserve system is
inoptimally chosen. Historically researvations have often been
established because:
 The opportunity cost was low since the land had few competing
uses. This can explain why many protected areas have been
established in the mountain region, while a relatively small share
of the nature in southern Sweden has been protected. Similar
trends can be found in other countries.
 Estetic reasons may have been important. A certain nature area
may have been protected because of a majestic waterfall or some
strangely shaped rocks were there. This type of nature
conservation can be motivated on recreational grounds.
 Other reasons. The recreational needs of citizens in large cities
can motivate the establishment of protected areas near such
cities. Chance can also play a role, like if areas have been donated
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to the state.
Land area of Sweden divided in ownership categories and geographical areas, share
in reservations (% res), according to the Swedish National Forest Inventory
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Guiding principles behind a reserve network
Complementarity. With limited resources to establish new reservations they should be
chosen to complement already existing ones. Reservations in mountain regions can be
complemented with reservations in the forest land, reservations in the northern part of a
country can be complemented with reservations in the southern part, etc. Together the
reservations can encompass most nature types in a country.
Flexibility. Often several sites can fulfill the same biodiversity goals. One should
therefore not be locked at certain areas in say, the mountain region, if there are substitute
sites that give the same protection of biodiversity.
Irreplaceability. Certain areas may be irreplaceable in a reserve network, for instance in
the sense that certain threatened species only exist in a certain area. For these areas no
substitutes exist and complete coverage of all threatened species cannot be achieved (in
the sense that they are represented in the reserve network) cannot be reached unless they
are chosen.
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*The problem – called the Maximum Coverage
Problem (MCP):
Find a set of reserves that ”covers” as many species as possible in as small an area as
possible (MCP1).
Maximize the number of ”covered” species within a given budget, where different areas
have specific cost associated with setting them aside (MCP2).
*Information requirements: -MCP1: A geographical species data base.
-MCP2: As in MCP 1 + a geographical land value data
base.
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Example of a geographical species data base.
Species 1
Species 2
……….
Species n
Area 1
1
0
……….
1
Area 2
0
1
……….
1
:
:
:
:
:
:
:
:
Area m
0
0
1
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*One
way to find the optimal solution is through integer programming
using branch-and-bound algoritmer  computer intensive method if the
number of species and/or areas is large.
*A number of heuristic ( approximative) algorithms exist, which can find
a nearly optimal solution.
The Greedy Algorithm:
First choose the area with the most
species, then the area with the most
species that didn’t exist in the first area,
and so on.
The Rarity Algorithm:
Weigth each species by
1
, then
Nj
choose the area with the largest sum of
“species weights”. Remove the “covered”
species from the process and redo the
iteration.
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Simple example: choose 2 out of 4 areas as
reserves
A och B är hotspots.
According to the Greedy Algorithm we should choose either A or B, then either C or
D
But the obvious optimal choice is C and D.
Illustrates the importance of complementarity.
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*the Oregon study – some results: -Optimal solution:
90% of the species could be covered with 5
areas out of 441, i.e. 1,1% of the area of Oregon.
All the species could be covered with 23 areas
out of 441, 5,2% of the area of Oregon.
The Greedy Algorithm was nearly optimal when
only a few areas could be selected, so that
not all species could be covered.
•
The Rarity Algorithm was nearly optimal when
it came to covering all species (24 areas
rather than the optimal 23 was needed).
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450
Antal representerade arter
430
410
390
370
350
330
310
290
270
250
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Girighetsalgoritmen
Ovanlighetsalgoritmen
Optimal lösning - heltalsprogrammering
Antal områden i
reservatsnätverket
Species accumulation curves
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The Rarity Algorithm gives high weight to unusual species.
There is not only one but 144(!) optimal solutions.
How come? Several areas are perfect substitutes to each
other.
But 19 of the 23 areas appear in all the 144 solutions and
are thus irreplaceable in a reserve network.
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Irreplaceability values for Oregon reserves.
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*If costs are included the problem changes
(MCP2):
(1)
Max.  yi
i I
s. t .
 x j  yi
j Ni
cjxj  B
j J
i  I
(2)
(3)
yi = species i
I = tot. number of species
x j = area j
J = tot. number of areas
Ni  J = areas where species i exist, subset of J
c j = cost for conserving area j
B = budget restriction
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*Example - County USA study (Ando et al., 1998, Science)
*Based on occurrence data on the 911 species
That are listed under the Endangered Species Act.
*USA has 2851 counties. Land value = value of agricultural land.
*Assumption:
Species are evenly distributed within a county. It is therefore
Enough to conserve arbitrarily large area in every chosen
county. The size of this area does not influence the choice of
counties.
*Results:
The cost of conserving 50% of the threatened species is only
7,5% of the cost of conserving all of them.
Reason:
To conserve all threatened species some counties
with extremely high land values, like
San Fransisco county must be included.
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Concluding thoughts
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Conservation and economics
Economic research has much to contribute with when it comes to making rational
decisions in conservation issues, for instance through cost-efficiency analyses and
CBA.
Conservation biology – an established research field.
In a similar way one could talk about Conservation economics as a research field.
There are many challenges:
To measure the value of ecosystem services
To measure existence values
To integrate realistic ecological models with economics
Spatial issues (migration, reserve site selection, etc.)
Species interactions (predator-prey models under human harvesting, competition,
etc.)
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Conservation and economics (continued)
More challenges:
Irreversibilities (extinction etc.)
Incorporate climate change
Technological development
This requires cooperation between economists and ecologists!
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