"Ecosystem Services" Essay by Heather Tallis and Peter Karieva
Magazine
R1
Essay
Ecosystem
services
Heather Tallis1 and Peter
Kareiva2
Humans have always depended
on nature for environmental assets
like clean water, nutrient cycling
and soil formation. These have
been called by different names
The Indonesian mangrove habitats shown above are relatively low in biodiversity
through human history, but are
(compared to other tropical habitats), yet are among the world’s most valuable
presently gaining global attention
ecosystems when one accounts for their storm protection, fisheries production, and
as ‘ecosystem services’. Gretchen water supply. In fact mangroves are estimated to provide ecosystem services at a per
Daily defines ecosystem services hectare rate ($9,900 per year) nearly five times higher than the per hectare rate for
as “the conditions and processes tropical forests, which are noted for their high biodiversity. Thus, at a global scale,
through which natural high biodiversity does not necessarily correspond to the greatest ecosystem services
— a reality that may cause conservation efforts to broaden their goals beyond simply
ecosystems, and the species that
maximizing biodiversity.
make them up, sustain and fulfill
human life”. Until recently, we
have tended to take ecosystem importance of ecosystem Millenium Ecosystem Assessment
services for granted, as they have processes and other forms of identified functions as
generally been ‘free’, despite their capital (physical, social, cultural, provisioning (food, water, fuel,
obvious economic value to intellectual). Economic valuation fiber), regulating (prevention of
humans. In fact, a recent global need not cover all values of soil erosion, flood control), cultural
analysis by the Millenium ecosystems; progress is made (recreation, spiritual value, sense
Ecosystem Assessment simply by capturing values that of place) or supporting (soil
concluded that well over half of are presently egregiously formation, nutrient cycling, oxygen
the world’s ecosystem services overlooked. As a society, the from photosynthesis).
are being degraded or used modern world routinely uses Regardless of the ways they can
unsustainably. With a global cost–benefit analyses to judge be grouped, ecosystem services
population soon to number nine between alternative pathways. have been brought into the
billion people, ecosystems The valuation of ecosystem limelight largely due to interest
services are becoming so services facilitates difficult from multiple, usually disparate,
degraded that many regions in the decisions about how to proceed sectors. Corporations and private
world risk ecological collapse. It with development to keep up with land owners have begun to
may be time for the era of free ever-expanding human recognize that their resource
ecosystem services to come to an populations. Without economic bases are finite and are, in some
end. The idea of paying for valuation, decision-makers and cases, factoring ecosystem well-
ecosystem services is causing governments implicitly assign being into the corporate or
corporations, private land owners, ecosystem processes a value of individual balance-sheet. For
conservation organizations and zero and, not surprisingly, then instance, British Petroleum gained
governments to take note. Even select actions that reap rewards support from the public, and even
prominent business-oriented according to values everyone some conservation organizations,
magazines such as The Economist already understands (like a new in their bold move to break from
have recently featured ecosystem factory). Hence valuation, even if it the fossil fuels industry by publicly
services on their cover (see the 21 is flawed, may get ecosystem recognizing the association
April 2005 issue). processes on the table and lead to between fossil fuels and climate
If we are to start paying for more sustainable policies. change, and then selecting a
ecosystem services, we have to Several attempts have been corporate strategy that reflected
know how much to pay. made to classify and exhaustively the role of carbon sequestration
Economists and ecologists are list ecosystem services. There is and reduced emissions in climate
just beginning to credibly assign no present consensus on a useful control. On a less grand, but
economic value to ecosystem taxonomy, though de Groot and equally relevant scale, cattle
processes, transforming these coworkers and the Millenium ranchers and foresters may use
processes into tradable, Ecosystem Assessment have both ecosystem services as another
marketable services. This established groupings that align commodity that can be sold
approach gives us a common ecosystem functions with goods beyond beef or timber, as long as
currency to assess the relative and services. For example, the they can find someone willing to
Current Biology Vol 15 No 17
R2
thinking about nature, differences
Box 1 of opinion can be dramatic. For
example, some scientists suggest
Mangroves: from $2000 shrimp to tsunami protection
a virtual one-to-one mapping
between ecosystem services and
Mangroves have long been the poster child of Mangroves have also illustrated the
biodiversity. Others point out that
ecosystem services. The list of the services importance of understanding what ecosystem
there are many cases where low
provided by mangroves is long and well characteristics are necessary for particular
appreciated by subsistence communities services. The recent Indian Ocean tsunami diversity systems can provide
globally. Many of these services have already provided a textbook example of the role of
tremendous ecosystem services,
been targets of valuation studies, including mangroves in coastal protection. Most areas
and that modest losses of
finfish and non-finfish commercial and in Sri Lanka with relatively good mangrove
biodiversity may not substantially
subsistence fisheries, timber and firewood, status before the tsunami were protected and
undermine ecosystem services.
dyes, tourism, medicinal remedies, education, received little wave damage as expected, but
Many conservationists also fear
physical coastal protection, carbon storage, some were severely damaged. In other
that placing values on ecosystem
and even existence and option values. The words, the mangroves acted like an
services will lead to the loss of
power of such valuations was shown early insurance policy against storm damage
appreciation of species for their
on, when the Fijian government temporarily nature s insurance policy, with no premiums
own sake. History has shown that
stopped mangrove reclamation in the 1960 s charged to anyone. Of course, if all of the
and 1970 s after seeing the results of a partial coastal regions bludgeoned by the tsunami markets are generally unkind to
valuation study. had recognized the value of mangroves,
natural systems. Others see
much damage and suffering could have been
markets as tools that can instill
A later case study showed the economic and
averted.
ecological perils of neglecting the value of conservation value into lands
mangroves. A large mangrove area on India s Interestingly, just as is the case with regular
under human use that would
east coast houses a shrimp farming industry insurance policies, the details matter. A
traditionally not be valued if the
that relies on wild brood shrimp. But, closer look at the patterns of damage and the
only measure were biodiversity.
mangroves were cleared for new farms coastal vegetation showed that the damaged
Possibly the boldest move to
subsidized by the government and the areas had dominant mangrove trees like
embrace and understand
remaining mangrove area is half of that Rhizophora sp. in good condition, but had
ecosystem services to date is the
required just to provide enough wild brood understories dominated by less typical
Millennium Ecosystem
shrimp for existing farms. Overdevelopment mangrove associates (species not always
Assessment, mentioned above.
has led to a wildly fluctuating brood shrimp found in mangroves). This detail of forest
market where a single shrimp can sell for as character, not visible from satellites, made all This assessment of the status of
much as $2000 USD. Analyzing the partial the difference. If mangrove restoration efforts
the earth’s ecosystems was
value of mangroves for brood shrimp spurred by the recent disaster focus on
requested by the United Nations
provision alone would have clearly identified expanding the extent of major mangrove
Secretary General, Kofi Annan. As
the optimal number of farms, saving subsidy species while ignoring understory species,
stated in the report: “the objective
money, providing a sustainable industry and the region could face an equally grave threat
of the Millenium Ecosystem
retaining more mangroves. from the next tsunami.
Assessment was to assess the
consequences of ecosystem
change for human well-being and
pay for clean watersheds or interested in ecosystem services. to establish the scientific basis for
erosion control. Private donor dollars presently actions needed to enhance the
Ecosystem services have also pay for most domestic and conservation and sustainable use
piqued the interest of the public international conservation of ecosystems and their
sector and national governments. activities. Though these funds contributions to human well-
For example, several agencies have set aside vast tracts of being”. The assessment cost over
within the US government pristine systems, they alone will $20 million and involved 1300
(USEPA, USACE, USDA) recently not be enough to protect the scientists who volunteered their
showed their interest in majority of the earth’s ecosystems time synthesizing and analyzing
ecosystem services when they and the species they house. In data and models.
commissioned the National comparison, realization of the All of this interest is derived
Research Council to produce a market worth of ecosystem from a healthy base of theory and
report on the topic and the status services has the potential to only a few real-world examples
of aquatic ecosystem services in increase conservation funding by that scratch the surface of
the US. These government orders of magnitude. Ecosystem possible tools for the sticky
agencies recognize the utility of services also have the possibility business of assigning values to
ecosystem service valuation for of aligning conservation value and ecosystem functions. The point of
its potential to inform policy poverty alleviation. Functioning economic valuation is to estimate
decisions that include ecosystems provide clean, the importance of changes in
consideration of trade-offs, for disease-free water, fertile soil and ecosystem services to human
providing damage assessments numerous other basic human welfare. There is an active
and for incorporating needs. movement to formalize ecosystem
environmental assets and services The paradigm of ecosystem service values in public and
into national income accounts. services is not accepted by private sectors by creating
Conservation organizations everyone, and even among those markets for ecosystem services,
have several reasons to be who champion this new way of and at a minimum changing
Magazine
R3
Fish for personal
policies away from perverse
consumption caught by net
subsidies.
from a coral reef in
The most common and most
Indonesia. Although the
appropriate approach to non- importance of coral reefs
market valuation is called total for fisheries is well-known,
economic value (TEV). This unsustainable practices
such as blast fishing
approach does not necessarily
commonly squander these
assess the total value of an
ecosystem services, and
ecosystem, but rather allows
leave future generations
changes to be calculated for all deprived. In this Indonesian
values (use and non-use values) community, blast fishing
associated with one or several had been halted, and local
people enjoy a bountiful
ecosystem functions. Any
harvest of fish. If blast
calculation of TEV will depend
fishing yields too much
heavily on the spatial and
short-term economic gain
temporal scales being assessed, due to exports to Japan or
so analysts must be clear about elsewhere, the wisdom of
the intended scope of their study. sustainable practices does
not so easily triumph.
TEV can be assessed as
willingness to pay (WTP) or
willingness to accept (WTA)
payment. WTP is the more service, or some other form of potential may be even riskier as
common method, as more tools incentive. Some payment systems species continue to blink out of
for estimating economic value are are already established and existence and ecosystems
relevant to this approach and functioning for selected continue to collapse around us.
WTP can usually be considered a ecosystem services. For example,
conservative estimate in cases there are at least five active Further reading
Costanza, R., d’Arge, R., de Groot, R.,
where WTA would be preferred. carbon markets in the world, and
Farber, S., Grasso, M., Hannon, B.,
The recent NRC report reviews farmers in parts of the US are
Limburg, K., Naeem, S., O’Neill,
the many methods for calculating subsidized to leave fields fallow R.V., Paruelo, J., et al. (1997). The
WTP and should be consulted for for several years to encourage soil value of the world’s ecosystem
services and natural capital. Nature
details and guidelines. formation and retention. The
387, 253–259.
Many problems must be solved Perrier bottled water company
Daily, G.C. ed. (1997). Nature’s
before the valuation of ecosystem pays fees to landowners in Services: Societal Dependence on
services can become a watersheds upstream of their Natural Ecosystems (Washington:
Island Press).
mainstream activity. Primarily, we springs to retain forests,
Millennium Ecosystem Assessment.
need to acquire sufficient guaranteeing a clean, reliable
(2005). Ecosystems and human
information about ecosystem water source. But even these well-being:synthesis (Washington:
processes to make valuation tools will be difficult to apply in Island Press).
possible. Beyond that basic non-capitalist countries or Postel, S., and Thompson, B.H. (2005).
Watershed protection:capturing the
biophysical information, we also developing regions with minimal
benefits of nature’s water supply
lack an understanding of how infrastructure. Economists and services. Nat. Resour. Forum 29,
economic value scales with multilateral international agencies 98–105.
ecosystem processes. For will need to apply creative Valuing Ecosystem Services. (2004).
Towards better environmental
instance, a single wetland grass thinking in impoverished countries
decision making (Washington:
plant does not cycle enough to help the value of ecosystem
National Academies Press).
nutrients to be of value to an services be realized in places www.ecosystemservicesproject.org
upland cattle farmer. But how where no one can afford to pay for (CSIRO initiated project studying
ecosystem services and how to
many plants are considered much of anything.
consider these services in land
valuable? 100 plants? One hectare Valuation of ecosystem services
management decisions)
of wetland? And how does this is but one of many tools that will www.ecosystemvaluation.org/(funda-
answer change with seasons, be used in the continual struggle mentals of dollar valuation, with
links to indicators of ecosystem
climate fluctuations and land use to allow coexistence of humans
value)
change in the watershed? and the suite of species and
http://esd.uvm.edu/ (NSF funded
Another challenge lies in our ecosystems that make our lives ecosystem services database and
ability to devise pragmatic possible. Ecosystem services and search tool)
programs for the monetization of their dollar value is one of the few www.actionbioscience.org/environ-
ment/esa.html (Ecological Society
services. Hardest of all may be ideas that resonate in corporate
of America factsheet on ecosystem
finding someone willing to pay, and governmental board rooms, services with links)
when the tradition has been to on stock exchanges and in farm
receive these services for free. houses, mud huts, eco-tourist 1Biology, University of Washington,
Ecosystem service valuation will lodges and palm palapas. Seattle, Washington 98195, USA.
2The Nature Conservancy, 4722 Latona
only achieve its promise if there Investing in ecosystem services is
Avenue NE Seattle, Washington 98105,
are markets and buyers for the a risky business. Ignoring their
USA.
R1
Essay
Ecosystem
services
Heather Tallis1 and Peter
Kareiva2
Humans have always depended
on nature for environmental assets
like clean water, nutrient cycling
and soil formation. These have
been called by different names
The Indonesian mangrove habitats shown above are relatively low in biodiversity
through human history, but are
(compared to other tropical habitats), yet are among the world’s most valuable
presently gaining global attention
ecosystems when one accounts for their storm protection, fisheries production, and
as ‘ecosystem services’. Gretchen water supply. In fact mangroves are estimated to provide ecosystem services at a per
Daily defines ecosystem services hectare rate ($9,900 per year) nearly five times higher than the per hectare rate for
as “the conditions and processes tropical forests, which are noted for their high biodiversity. Thus, at a global scale,
through which natural high biodiversity does not necessarily correspond to the greatest ecosystem services
— a reality that may cause conservation efforts to broaden their goals beyond simply
ecosystems, and the species that
maximizing biodiversity.
make them up, sustain and fulfill
human life”. Until recently, we
have tended to take ecosystem importance of ecosystem Millenium Ecosystem Assessment
services for granted, as they have processes and other forms of identified functions as
generally been ‘free’, despite their capital (physical, social, cultural, provisioning (food, water, fuel,
obvious economic value to intellectual). Economic valuation fiber), regulating (prevention of
humans. In fact, a recent global need not cover all values of soil erosion, flood control), cultural
analysis by the Millenium ecosystems; progress is made (recreation, spiritual value, sense
Ecosystem Assessment simply by capturing values that of place) or supporting (soil
concluded that well over half of are presently egregiously formation, nutrient cycling, oxygen
the world’s ecosystem services overlooked. As a society, the from photosynthesis).
are being degraded or used modern world routinely uses Regardless of the ways they can
unsustainably. With a global cost–benefit analyses to judge be grouped, ecosystem services
population soon to number nine between alternative pathways. have been brought into the
billion people, ecosystems The valuation of ecosystem limelight largely due to interest
services are becoming so services facilitates difficult from multiple, usually disparate,
degraded that many regions in the decisions about how to proceed sectors. Corporations and private
world risk ecological collapse. It with development to keep up with land owners have begun to
may be time for the era of free ever-expanding human recognize that their resource
ecosystem services to come to an populations. Without economic bases are finite and are, in some
end. The idea of paying for valuation, decision-makers and cases, factoring ecosystem well-
ecosystem services is causing governments implicitly assign being into the corporate or
corporations, private land owners, ecosystem processes a value of individual balance-sheet. For
conservation organizations and zero and, not surprisingly, then instance, British Petroleum gained
governments to take note. Even select actions that reap rewards support from the public, and even
prominent business-oriented according to values everyone some conservation organizations,
magazines such as The Economist already understands (like a new in their bold move to break from
have recently featured ecosystem factory). Hence valuation, even if it the fossil fuels industry by publicly
services on their cover (see the 21 is flawed, may get ecosystem recognizing the association
April 2005 issue). processes on the table and lead to between fossil fuels and climate
If we are to start paying for more sustainable policies. change, and then selecting a
ecosystem services, we have to Several attempts have been corporate strategy that reflected
know how much to pay. made to classify and exhaustively the role of carbon sequestration
Economists and ecologists are list ecosystem services. There is and reduced emissions in climate
just beginning to credibly assign no present consensus on a useful control. On a less grand, but
economic value to ecosystem taxonomy, though de Groot and equally relevant scale, cattle
processes, transforming these coworkers and the Millenium ranchers and foresters may use
processes into tradable, Ecosystem Assessment have both ecosystem services as another
marketable services. This established groupings that align commodity that can be sold
approach gives us a common ecosystem functions with goods beyond beef or timber, as long as
currency to assess the relative and services. For example, the they can find someone willing to
Current Biology Vol 15 No 17
R2
thinking about nature, differences
Box 1 of opinion can be dramatic. For
example, some scientists suggest
Mangroves: from $2000 shrimp to tsunami protection
a virtual one-to-one mapping
between ecosystem services and
Mangroves have long been the poster child of Mangroves have also illustrated the
biodiversity. Others point out that
ecosystem services. The list of the services importance of understanding what ecosystem
there are many cases where low
provided by mangroves is long and well characteristics are necessary for particular
appreciated by subsistence communities services. The recent Indian Ocean tsunami diversity systems can provide
globally. Many of these services have already provided a textbook example of the role of
tremendous ecosystem services,
been targets of valuation studies, including mangroves in coastal protection. Most areas
and that modest losses of
finfish and non-finfish commercial and in Sri Lanka with relatively good mangrove
biodiversity may not substantially
subsistence fisheries, timber and firewood, status before the tsunami were protected and
undermine ecosystem services.
dyes, tourism, medicinal remedies, education, received little wave damage as expected, but
Many conservationists also fear
physical coastal protection, carbon storage, some were severely damaged. In other
that placing values on ecosystem
and even existence and option values. The words, the mangroves acted like an
services will lead to the loss of
power of such valuations was shown early insurance policy against storm damage
appreciation of species for their
on, when the Fijian government temporarily nature s insurance policy, with no premiums
own sake. History has shown that
stopped mangrove reclamation in the 1960 s charged to anyone. Of course, if all of the
and 1970 s after seeing the results of a partial coastal regions bludgeoned by the tsunami markets are generally unkind to
valuation study. had recognized the value of mangroves,
natural systems. Others see
much damage and suffering could have been
markets as tools that can instill
A later case study showed the economic and
averted.
ecological perils of neglecting the value of conservation value into lands
mangroves. A large mangrove area on India s Interestingly, just as is the case with regular
under human use that would
east coast houses a shrimp farming industry insurance policies, the details matter. A
traditionally not be valued if the
that relies on wild brood shrimp. But, closer look at the patterns of damage and the
only measure were biodiversity.
mangroves were cleared for new farms coastal vegetation showed that the damaged
Possibly the boldest move to
subsidized by the government and the areas had dominant mangrove trees like
embrace and understand
remaining mangrove area is half of that Rhizophora sp. in good condition, but had
ecosystem services to date is the
required just to provide enough wild brood understories dominated by less typical
Millennium Ecosystem
shrimp for existing farms. Overdevelopment mangrove associates (species not always
Assessment, mentioned above.
has led to a wildly fluctuating brood shrimp found in mangroves). This detail of forest
market where a single shrimp can sell for as character, not visible from satellites, made all This assessment of the status of
much as $2000 USD. Analyzing the partial the difference. If mangrove restoration efforts
the earth’s ecosystems was
value of mangroves for brood shrimp spurred by the recent disaster focus on
requested by the United Nations
provision alone would have clearly identified expanding the extent of major mangrove
Secretary General, Kofi Annan. As
the optimal number of farms, saving subsidy species while ignoring understory species,
stated in the report: “the objective
money, providing a sustainable industry and the region could face an equally grave threat
of the Millenium Ecosystem
retaining more mangroves. from the next tsunami.
Assessment was to assess the
consequences of ecosystem
change for human well-being and
pay for clean watersheds or interested in ecosystem services. to establish the scientific basis for
erosion control. Private donor dollars presently actions needed to enhance the
Ecosystem services have also pay for most domestic and conservation and sustainable use
piqued the interest of the public international conservation of ecosystems and their
sector and national governments. activities. Though these funds contributions to human well-
For example, several agencies have set aside vast tracts of being”. The assessment cost over
within the US government pristine systems, they alone will $20 million and involved 1300
(USEPA, USACE, USDA) recently not be enough to protect the scientists who volunteered their
showed their interest in majority of the earth’s ecosystems time synthesizing and analyzing
ecosystem services when they and the species they house. In data and models.
commissioned the National comparison, realization of the All of this interest is derived
Research Council to produce a market worth of ecosystem from a healthy base of theory and
report on the topic and the status services has the potential to only a few real-world examples
of aquatic ecosystem services in increase conservation funding by that scratch the surface of
the US. These government orders of magnitude. Ecosystem possible tools for the sticky
agencies recognize the utility of services also have the possibility business of assigning values to
ecosystem service valuation for of aligning conservation value and ecosystem functions. The point of
its potential to inform policy poverty alleviation. Functioning economic valuation is to estimate
decisions that include ecosystems provide clean, the importance of changes in
consideration of trade-offs, for disease-free water, fertile soil and ecosystem services to human
providing damage assessments numerous other basic human welfare. There is an active
and for incorporating needs. movement to formalize ecosystem
environmental assets and services The paradigm of ecosystem service values in public and
into national income accounts. services is not accepted by private sectors by creating
Conservation organizations everyone, and even among those markets for ecosystem services,
have several reasons to be who champion this new way of and at a minimum changing
Magazine
R3
Fish for personal
policies away from perverse
consumption caught by net
subsidies.
from a coral reef in
The most common and most
Indonesia. Although the
appropriate approach to non- importance of coral reefs
market valuation is called total for fisheries is well-known,
economic value (TEV). This unsustainable practices
such as blast fishing
approach does not necessarily
commonly squander these
assess the total value of an
ecosystem services, and
ecosystem, but rather allows
leave future generations
changes to be calculated for all deprived. In this Indonesian
values (use and non-use values) community, blast fishing
associated with one or several had been halted, and local
people enjoy a bountiful
ecosystem functions. Any
harvest of fish. If blast
calculation of TEV will depend
fishing yields too much
heavily on the spatial and
short-term economic gain
temporal scales being assessed, due to exports to Japan or
so analysts must be clear about elsewhere, the wisdom of
the intended scope of their study. sustainable practices does
not so easily triumph.
TEV can be assessed as
willingness to pay (WTP) or
willingness to accept (WTA)
payment. WTP is the more service, or some other form of potential may be even riskier as
common method, as more tools incentive. Some payment systems species continue to blink out of
for estimating economic value are are already established and existence and ecosystems
relevant to this approach and functioning for selected continue to collapse around us.
WTP can usually be considered a ecosystem services. For example,
conservative estimate in cases there are at least five active Further reading
Costanza, R., d’Arge, R., de Groot, R.,
where WTA would be preferred. carbon markets in the world, and
Farber, S., Grasso, M., Hannon, B.,
The recent NRC report reviews farmers in parts of the US are
Limburg, K., Naeem, S., O’Neill,
the many methods for calculating subsidized to leave fields fallow R.V., Paruelo, J., et al. (1997). The
WTP and should be consulted for for several years to encourage soil value of the world’s ecosystem
services and natural capital. Nature
details and guidelines. formation and retention. The
387, 253–259.
Many problems must be solved Perrier bottled water company
Daily, G.C. ed. (1997). Nature’s
before the valuation of ecosystem pays fees to landowners in Services: Societal Dependence on
services can become a watersheds upstream of their Natural Ecosystems (Washington:
Island Press).
mainstream activity. Primarily, we springs to retain forests,
Millennium Ecosystem Assessment.
need to acquire sufficient guaranteeing a clean, reliable
(2005). Ecosystems and human
information about ecosystem water source. But even these well-being:synthesis (Washington:
processes to make valuation tools will be difficult to apply in Island Press).
possible. Beyond that basic non-capitalist countries or Postel, S., and Thompson, B.H. (2005).
Watershed protection:capturing the
biophysical information, we also developing regions with minimal
benefits of nature’s water supply
lack an understanding of how infrastructure. Economists and services. Nat. Resour. Forum 29,
economic value scales with multilateral international agencies 98–105.
ecosystem processes. For will need to apply creative Valuing Ecosystem Services. (2004).
Towards better environmental
instance, a single wetland grass thinking in impoverished countries
decision making (Washington:
plant does not cycle enough to help the value of ecosystem
National Academies Press).
nutrients to be of value to an services be realized in places www.ecosystemservicesproject.org
upland cattle farmer. But how where no one can afford to pay for (CSIRO initiated project studying
ecosystem services and how to
many plants are considered much of anything.
consider these services in land
valuable? 100 plants? One hectare Valuation of ecosystem services
management decisions)
of wetland? And how does this is but one of many tools that will www.ecosystemvaluation.org/(funda-
answer change with seasons, be used in the continual struggle mentals of dollar valuation, with
links to indicators of ecosystem
climate fluctuations and land use to allow coexistence of humans
value)
change in the watershed? and the suite of species and
http://esd.uvm.edu/ (NSF funded
Another challenge lies in our ecosystems that make our lives ecosystem services database and
ability to devise pragmatic possible. Ecosystem services and search tool)
programs for the monetization of their dollar value is one of the few www.actionbioscience.org/environ-
ment/esa.html (Ecological Society
services. Hardest of all may be ideas that resonate in corporate
of America factsheet on ecosystem
finding someone willing to pay, and governmental board rooms, services with links)
when the tradition has been to on stock exchanges and in farm
receive these services for free. houses, mud huts, eco-tourist 1Biology, University of Washington,
Ecosystem service valuation will lodges and palm palapas. Seattle, Washington 98195, USA.
2The Nature Conservancy, 4722 Latona
only achieve its promise if there Investing in ecosystem services is
Avenue NE Seattle, Washington 98105,
are markets and buyers for the a risky business. Ignoring their
USA.