I. INTRODUCCIÓN
2.2. TIPOS DE UNIONES CELULARES
2.2.2. Uniones célula-matriz
New Zealand has a long history of non-market valuation. The first New Zealand studies in this field were undertaken by Russell Gluck (1974), who measured the values associated with recreational angling, and by Woodfield & Cowie (1977), who measured the value of a backcountry tramping experience in Fiordland National Park. Since then, over 130 non-market valuation studies have been recorded on the New Zealand Non-Market Valuation Database, which is maintained by Lincoln University115; and reasonably detailed summaries of many New Zealand non-market valuation studies are now available on the extremely comprehensive, international EVRI
database116. VALUEbase117, which is funded by the Swedish Environmental Protection Agency, and the New South Wales government database ENValue118 have also been useful sources of values; however, neither of these have been maintained, with VALUEbase last updated in December 2004 and ENValue in April 2004. Despite TEEB (2011: chapter 4) noting them as popular databases for ecosystem valuation, the ARIES database119 does not contain any New Zealand studies and the RED database is no longer available. The following analysis of New Zealand applications of non-market valuation is based on studies contained in the New Zealand Non-Market Valuation Database. In keeping with studies in other countries, New Zealand non-market valuation studies have primarily focussed on four of Max-Neef’s (1991) fundamental needs: subsistence, protection, affection and leisure values. To our knowledge, no studies have attempted to place a monetary value on understanding, participation, creation, identity or freedom. Therefore, in the rest of this section, we use examples of New Zealand studies to illustrate the importance that the community places on only those ecosystem services that have been valued.
Subsistence
Subsistence service values, such as the value of food, are frequently measured in markets. For example, the annual value of groundwater sourced from the Waimea Plains was estimated to be about $250 million—approximately $40 million to irrigators (essentially the value of increased food production), $173 million to industrial users and $33 million to the bulk water supplier (White et al. 2001).
In addition to marketed services, ecosystem services also include non-marketed subsistence services, which arise from the use of resources such as water, which has both quantity and quality attributes. For example, Welsh (1991) estimated the mean annual household benefits of the Christchurch domestic water supply at $2500. Similarly, Creagh (2010) measured the value of maintaining the cleanliness of domestic water supplies in Auckland and Christchurch, finding that Auckland households were willing to pay about $180 extra each year in addition to the average water charge of $267 (total = $447) for the maintenance of clean water and Christchurch households were willing to pay in the order of $400 extra each year in addition to the average water charge of $85 (total = $485). Furthermore, Kerr et al. (2003) showed that Christchurch
115 www2.lincoln.ac.nz/nonmarketvaluation/
116 Environmental Valuation Reference Inventory: www.evri.ca 117 www.beijer.kva.se/valuebase.htm
118 www.environment.nsw.gov.au/envalueapp/
households were willing to pay over $500 per year to augment the domestic water supply from new sources in order to avoid a diverse range of impacts on ecosystem services as a result of extra demand on the existing source, including changes in provisioning services.
Protection
Several studies have investigated the importance of flood protection to New Zealanders.
Samarasinghe & Sharp (2008) carried out a hedonic valuation study, which estimated that people were willing to pay a $22,000 premium on houses outside a floodplain. In a study of Waimakariri River floodplain residents, Kerr (1989) found that the average household was willing to pay $320 per annum to reduce the 30-year risk of flooding from 30% to 10%. Welsh (2001) assessed the value of reduced flooding to Waitakere City residents and found that there were aggregate annual benefits to the city of $35 million from the avoidance of flooding to 420 houses in a typical year. Investigations into other forms of protection include Tait et al. (2011), who estimated that Canterbury households were willing to pay $27 per year to reduce the risk of sickness from recreational water contact from 6% to 1%; Takatsuka et al. (2009), who determined that a 50% reduction in arable farming greenhouse gas emissions would lead to annual benefits of about $100 to Canterbury households; and Kerr & Cullen (1995), who valued the improvement of Paparoa National Park native forest conditions through the control of introduced possums at $300–400 per person per year.
Affection
Affection includes both affection for other people and affection for nature, with the latter being expressed in the concept of existence value. An early study that investigated this need was that of Kerr (1985), who estimated the value of avoiding hydroelectric development of the Kawarau River in Central Otago. The benefits came largely from protection of the natural landscape and amounted to $68 per household per year—a substantial amount when aggregated over all New Zealand households. Similarly, Mortimer et al. (1996) estimated that conservation benefits on Te Hauturu-o-Toi/Little Barrier Island had a total value of $9 million per year to Auckland households; and Yao & Kaval (2008), in their investigation into support for council biodiversity- enhancing tree planting programmes on public land, found that the programmes had mean benefits of $256 per person per year. Kerr & Sharp (2007) investigated the value to South Island residents of protecting endangered species in the Mackenzie Basin, and found that the protection of Hebe cupressoides from local extinction was valued at $41 million, assuming a 10% discount rate; and protection of the robust grasshopper (Brachaspis robustus) and the bignose galaxias (Galaxias macronasus), both of which are only found in the Mackenzie Basin, were valued at about $70 million each.
Leisure
The New Zealand Non-market Valuation Database contains 48 studies of recreation values, which are considered leisure services in Max Neef’s (1991) categorisation. Two of these studies summarise values obtained from New Zealand outdoor recreation studies: Kaval & Yao (2007) analysed 58 estimates from 19 studies to derive an overall mean120 of $71 per recreation day; and Kerr (2009) found that there were higher values for freshwater fishing, with a mean of $39 per angler-day121 compared with a mean of $25 per recreation day for other outdoor recreation activities. Beville & Kerr (2012) estimated that the invasion of Canterbury rivers by didymo (Didymosphenia geminata) would reduce leisure services from angling by $9.5 million122 per year.
120 Year 2007 dollars. 121 Quarter 1, year 2009 dollars. 122 Year 2008 dollars.
Services meeting multiple needs
Some studies do not fit neatly within Max-Neef’s needs typology, but underscore the role of ecosystem services. For example, a large number of studies have assessed the implications of water pollution on recreation and existence values. Water pollution can affect a range of ecosystem services, including provisioning services (both directly by making the water unsuitable for human consumption and indirectly by making it unsuitable for agricultural irrigation), leisure services (through impacts on recreational use), protection services (because of health risks) and affection services (because of implications for the functioning of the ecosystem that affect existence values). Combined, these effects can be extremely significant. For example, Sheppard et al. (1993) valued improvement in water quality from D to C standard in the lower Waimakariri River at $96 million. Similarly, Harris (1984: 205) estimated that Waikato residents would have benefitted by $3.7 million per annum from improvements in the water quality of the Waikato River as a result of ‘health, recreation, aesthetics and conservation values’ (Harris 1984: 205).
Increasingly, choice experiments are being carried out to identify the relative magnitude of values arising from different environmental attributes. In some cases, these can be separated into different ecosystem service categories, but not always. Examples of such studies include, inter alia, Baskaran et al. (2013), Kerr & Sharp (2008), Kerr & Sharp (2010), Kerr & Swaffield (2012), Marsh (2012), Marsh et al. (2011), Tait et al. (2011) and Takatsuka et al. (2009). For example, Kerr & Swaffield (2012) were able to demonstrate the relative importance of high-quality stream water, the avoidance of gorse (Ulex europaeus) on riverbanks, increased water clarity and increased local employment. This type of integrated study can provide guidance on the merits of alternative policies for the management of resources.
When making management decisions, trade-offs between ecosystem services often need to be made. One area that exemplifies such trade-offs is agricultural irrigation. For example, Harris (2012) estimated that the present value of increased agricultural production from the proposed Waitohi irrigation scheme in North Canterbury is in the order of $910 million, with a net present value estimated at $200 million, once the $710 million of costs are accounted for. However, reductions in several other services are offset against those gains, including changes in cultural services, such as the loss of recreational opportunities; loss of regulating services because of the risk of dam burst; and impacts on supporting services because of elevated nutrient discharges into the environment. Some of the trade-offs that have been assessed for this proposal are described in Box 15.