EMBARAZO Y LACTANCIA
25. MOXIFLOXACINA ACTIVIDAD
Many of the above-mentioned values can be quantified in monetary terms. Monetary or financial valuation methods fall into three basic types, each with its own repertoire of associated measurement issues (Table 2.4); direct market valuation, indirect market valuation and survey-based valuation (i.e. contingent valuation and group valuation).
If no site-specific data can be obtained (due to lack of data, resources or time), then benefit transfer can be applied (i.e. by using results from other, similar areas to approximate the value of a given service in the study site). This method is rather problematic because, strictly speaking, each decision-making situation is unique. However, as more data become available from new case studies, benefit transfer becomes more reliable.
Although Table 2.4 is based on various literature sources, and seeks to reflect a broad consensus on monetary valuation methods, other views and terminologies do exist. For example, Dixon and Pagiola (1998) use the term
Figure 2.2 The total economic value framework
Note: ‘bequest value’ is often also shown as another kind of (future) use (option) value.
Table 2.4 Monetary valuation methods, constraints and examples
Method Description Constraints Examples
1. Dir ect Mark et V aluation 2. Indir ect Mark et V aluation
Market price The exchange value (based on marginal productivity cost) that ecosystem services have in trade
Market imperfections and policy failures distort market prices
Mainly applicable to the ‘goods’ (e.g. timber) but also some cultural (e.g. recreation) and regulating services (e.g. pollination) Factor income or
productivity factor method
Measures effect of ecosystem services on loss (or gains) in earnings and/or productivity)
Care needs to be taken not to double- count values
Reversal of soil degradation which increases site quality and ecosystem productivity and thereby incomes of forest owners Public pricing * Public investments, e.g.
land purchase, or monetary incentives (taxes/subsidies) for ecosystem service use or conservation
Property rights sometimes difficult to establish; care must be taken to avoid perverse incentives Investments in watershed protection to provide drinking water, or conservation measures Avoided (damage) cost method
Services that allow society to avoid costs that would have been incurred in the absence of those services
It is assumed that the costs of avoided damage or
substitutes match the original benefit; however, this match may not be accurate, which can lead to underestimates as well as
overestimates.
The value of the flood control service can be derived from the estimated damage if flooding would occur
Replacement cost and substitution cost
Some services could be replaced with human- made systems
The value of groundwater recharge can be estimated from the costs of obtaining water from another source (substitute costs) Mitigation or
restoration cost
Cost of moderating effects of lost functions (or of their restoration)
E.g. cost of preventive expenditures in absence of wetland service (e.g. flood barriers) or relocation Travel cost method Use of ecosystem
services may require travel and the associated costs can be seen as a reflection of the implied value
Overestimates are easily made; the technique is data intensive
E.g. part of the recreational value of a site is reflected in the amount of time and money that people spend while travelling to the site Hedonic pricing
method
Reflection of service demand in the prices people pay for associated marketed goods
The method only captures people’s willingness to pay for perceived benefits; very data intensive
For example: clean air, presence of water and aesthetic views will increase the price of surrounding real estate
‘change in output of marketable goods’ as a combined term for market price and factor income; and they combine avoided (damage) cost, replacement cost and mitigation cost into so-called ‘cost-based approaches’.
Each method has its advantages and disadvantages. Yet, in order to reach an approximation of the true contribution of native forests and plantations to human welfare and the economy, a mix of these methods should be applied to include all functions, and associated goods and services, in the decision- making process.
In Table 2.5, a first attempt is made to quantify the difference in service performance between native and planted forests.
By using a mix of valuation methods, based on over 100 case studies, Costanza et al (1997) came to a conservative estimate that the total economic value of native forests is, on average, between US$300 and 2000/ha/year (1994 values).
Although there are very few data available about the monetary value of ecosystem services provided by plantations, the data that are available indicate that the (average) TEV of plantations is lower than the average TEV of native forests (Fisher et al, 2008).
Table 2.4 continued
Method Description Constraints Examples
Contingent valuation method (CVM)
This method asks people how much they would be willing to pay (or accept as
compensation) for specific services through questionnaires or interviews
There are various sources of bias in the interview techniques; also there is controversy over whether people would actually pay the amounts they state in the interviews
It is often the only way to estimate non-use values; for example, a survey
questionnaire might ask respondents to express their willingness to increase the level of water quality in a stream, lake or river so that they might enjoy activities like swimming, boating, or fishing
Group valuation Same as contingent valuation (CV) but then as an interactive group process
The bias in a group CV is supposed to be less than in individual CV Uses results from other,
similar areas, to estimate the value of a given service in the study site
Values are site and context dependent and therefore in principle not transferable
When time to carry out original research is scarce and/or data is unavailable, benefit transfers can be use (but with caution)
3.
Surveys
4. Benefit Transfer
Source: In de Groot et al, 2006, compiled after Barbier et al, 1997; King and Mazotta, 2001; Wilson and
Table 2.5 Difference in provision of goods and services between natural and
plantation forests
Main Goods and services provided by forests Natural (2) Plan-
ecosystem US$/ha/ tation
services year (1) (3)
categories
Food (from harvesting forest wildlife or 3 43 0 gathering plant-products)
Raw materials (e.g. timber, fibre) 1 138 +
Energy resources (e.g. fuelwood, biofuels) 2 (incl. in + above) Fodder and fertilizer (e.g. leaves, other organic 1 (incl. in 0 matter) above)
Genetic resources (genes and genetic 2 16 –
information used for animal and plant breeding and biotechnology)
Natural medicines and pharmaceuticals 2 (incl. in – (e.g. drugs, models, tools, essay org.) above) Biochemicals (non-medicinal) (e.g. for dyes, 2 (incl. in – biocides, food-additives) above) Ornamental resources: wildlife used in e.g. 2 (incl. in raw – fashion, handicraft, jewellery, worship, souvenirs, materials) decoration, as pets and in landscaping
Air quality regulation (e.g. capturing dust 2 87 – particles, NOx fixation, etc)
Climate regulation 2 141 –
Including carbon sequestration and storage
Water quality regulation (filtering of 2 3 –
rainwater and run-off water)
Water regulation (buffering of extremes in 2 2 – run-off and river discharge)
Natural hazard regulation (reduction of storm 1 2 0 and flood damage)
Erosion prevention (soil retention and 3 96 –
prevention of landslides/siltation) and
maintenance and restoration of productive 10 soils
Biological control (reduction/prevention of 1 2 – – crop, livestock and/or human diseases by
providing a barrier or habitat for control of vectors)
Pollination (providing habitat for pollinators of 2 (incl. in – crops and wild plants) above)
Pr
ovisioning Services
Yet native forests are still converted into single-function land-use types (e.g. croplands) on a large scale even though proof is mounting that the total value of multi-functional use of natural and semi-natural landscapes is, in the long term, often economically more beneficial than short-term economic benefits generated by the converted systems (Balmford et al, 2002). Clearly,
Table 2.5 continued
Main Goods and services provided by forests Natural (2) Plan- ecosystem tation
services (3)
categories
Aesthetic information (non-recreational 2 (incl. in – enjoyment of scenery) recr.)
Recreation and nature-based tourism 2 66 –
Cultural heritage and identity (many people 2 2 – value a ‘sense of place’ which is often associated
with forests)
Inspiration (e.g. for art, folklore, national symbols, 2 (incl. in – architecture, design, advertising cultural) Spiritual and religious information (many 2 (incl. in – individuals and religions attach spiritual values to cultural) forests and/or individual species)
Educational information (both formal and 2 (incl. in – – informal education in nature) cultural) Science (ecosystems, incl. forests influence the 2 (incl. in – – type of knowledge systems developed by cultural) different cultures)
Refugium (provide habitat for resident plants 3 – – – and animals and migratory species and thus
contribute to maintenance of biodiversity and evolutionary processes
Nursery (provide reproduction habitat for ? ?
species with commercial value that spend their adult life elsewhere)
(1) Average monetary value of this service US$/ha/year (based on meta-analysis of over 100 studies by Costanza et al, 1997)
(2) Qualitative scale indicates relative performance of natural forests in providing the given services: 1 = low, 2 = medium, 3 = high
(3) +/0/– indicates difference in services-provision between natural and plantation forest (+ = service is enhanced, 0 = remains the same, – = service is reduced)
(*) based on publications mentioned in the table-title. Of course there are large differences between forest types and management regimes so this must be seen as a very rough indication and further study is needed.
Source: qualitative scale based on interpretation of information from Brown and Lugo, 1990; Parotta et al, 1997,
2002; Shelton et al, 2001; de Groot et al, 2002; MEA, 2003).
Cultur
al and
Amenity Services
(information functions)
these economic calculations must be interpreted with care but they can help to highlight the economic (and financial) implications of these ecosystem conversions and identify ‘winners and losers’, which can help to develop financing schemes for sustainable management. If all forest services were valued properly, and landholders received some of this value, then plantation establishment might become financially attractive in degraded areas where they could be environmentally very beneficial (e.g. to reduce erosion, improve control of the water table and provide resources and other services).