Measurement of the Threatened Biodiversity Existence Value Output: Application of the Reﬁned System of Environmental-Economic Accounting in the Pinus pinea Forests of Andalusia, Spain

: Are we able to determine the existence value output generated for society through the preservation of wild species threatened with extinction? In this article we defend the theory that the service of preserving threatened species with risk of extinction is an existence value output with a hidden transaction price if it can be established that there are consumer or state willingness to pay an additional tax above the government total cost to avoid an increase in one threatened species in relation to the number recorded at the opening of the accounting period. This output is estimated by adding the total cost and the additional consumer tax which the consumers state that they are willing to pay through a choice experiment survey. Our reﬁned monetary System of Environmental-Economic Accounting (rSEEA) extends the existence value output concept and valuation principles recommended by the United Nations. In this paper, this rSEEA was applied to Pinus pinea forests in protected as well as non-protected areas of Andalusia, Spain in 2010. The results show that the net value added from protected areas is 40% higher than that from non-protected areas. It is incidental that the environmental beneﬁts in both areas coincide.


Introduction
Mitigating the threat of extinction of wild species and the degradation/destruction of their natural habitats on the planet has been addressed by governments in many countries through public policies strictly regulating changes in land use and coastal areas as well as moving away from economic activities involving the extraction of plants and animals in national parks. Policies aimed at incentivising the development of economic activities in protected areas other than national parks are common. Regarding economic statistics, in the design of public policies for protected areas, governments do not provide the public service of environmental-economic accounts for protected and non-protected natural areas. The conventional System of National Accounts (SNAs) provides the gross domestic product (gross value added) of the commercial economic activities without uncovering the contribution of nature [1]. This limitation of the public statistics makes it difficult to determine the economic contribution of nature conservation policies to the gross value added at national/sub-national territory scale. Government policies on the preservation of wild species threatened with extinction (hereafter biodiversity) are aimed at mitigating and/or avoiding its irreversible loss and that of its habitats through regulating economic activities and prohibiting the commercial extraction of wild animals and woody products in national parks. Common to all types of protected area is the fact that the government regulations omit the implementation of ecosystem accounting. Since the Nagoya protocol came into force, the agendas of specialized government institutions have begun to include the debate on standardizing the regulations and implementation of monetary ecosystem accounting [2][3][4][5].
The tragedy of the accelerated irreversible loss of biodiversity due to the increase in the extraction of natural resources and changes in the use of land and aquatic areas may have been mitigated by protectionist regulations at global and national/sub-national scales, although the results are insufficient to stop the loss of wild species and their habitats on the planet [2,6]. Specialized institutions (e.g., United Nations Statistical Commission, Eurostat) and experts are constantly alerting governments on the urgency of avoiding/mitigating the effect of economic activities on the degradation and loss of biodiversity in natural areas, whether specifically designated as protected areas or not. New active investment policies are required for integrated management of biological and economic sustainability of territories at local, national, and global spatial scales. Regarding environmental management, it is considered that for active policies on biodiversity to be long-lasting, they must be based on the best scientific biophysical and economic knowledge available [7].
The biodiversity existence value output (hereinafter biodiversity output) refers only to the species preservation services at the transaction price stated by Andalusian passive consumers of these services. Thus, we do not measure the environmental benefits of the species incorporated in other outputs, such as for example, the recreational and cultural landscape. The simulated biodiversity output measured at the transaction price tends to be rejected by academic experts and national accountants [5,8]. Technical reports on the economic activities in protected areas do not directly address the contribution of biodiversity, but rather, show the output and/or values added of other conventional economic activities incorporated in the SNA which use the natural and environmental resources of the protected areas for free [9][10][11].
The exception to this rejection of the biodiversity output among scientific publications is that which deals with the estimation of net value added at regional level (with no distinction between protected and non-protected areas) of Andalusian forests as a whole [12] and cork and holm oak woodlands [13,14]. Studies estimating biodiversity outputs have also been carried out at the scale of publicly owned conifer forest farms located in protected areas of Andalusia, one focusing on forests of Pinus nigra Arn., Pinus halepensis Mill., Pinus sylvestris L. and Pinus pinaster Ait. [15] and another on Pinus pinea L. [16].
The objective of this research is to value the biodiversity output in protected and non-protected areas of Stone pine (Pinus pinea) forests (SPs) in Andalusia, Spain. The gross values added (GVA) and net values added (NVA) as well as the operating benefit (B) were divided into produced benefit (PB) and environmental benefit (EB). The latter is a term synonymous with ecosystem service (ES). The estimated number of threatened species and the economic results for the biodiversity of the SPs in protected and non-protected areas are compared.
The United Nations System of Environmental-Economic Accounting-Ecosystem Accounting (SEEA-EA) rejects the valuation of simulated transaction price of the biodiversity output [5,17]. This recommendation is not adopted in this article as we consider it to be inconsistent, bearing in mind the valuation methods and extension of the concept of economic output without market price as recommended in chapters 8-11 of the SEEA-EA (hereafter SEEA). Our refined SEEA (henceforth rSEEA) consists of incorporating the biodiversity benefit (B) at the simulated transaction price in the valuation of the biodiversity output. The biodiversity benefit is estimated using the choice experiment and simulated exchange value (SEV) methods which provide the valuation of the additional marginal willingness to pay of passive consumers.
In this article our rSEEA is applied in an area defined by the map tiles of the Spanish Forest Map in which the predominant canopy fraction corresponds to Pinus pinea (SP), an Land 2022, 11, 1119 3 of 21 area totalling 243,559 hectares of which 57% falls within protected areas and the remaining 43% in non-protected areas [18].
The biodiversity output (O) is estimated by aggregating the values of the additional consumer tax (ACT) marginal willingness to pay and the total cost (TC) of the biodiversity, representing the output of preserving the 104 wild biological species threatened with risk of extinction which are present in the protected and non-protected areas of the Stone pine forests (SPs) of Andalusia.
In the following sections of the article, we describe the concepts, methods, and results which explain the consistency of the results in terms of the economic rationale of the consumers and the government ecosystem trustee in the SPs of Andalusia.

Concept of Transaction Price of Biodiversity Output
This sub-section sustains the theory that biodiversity threatened with extinction can generate a demand function based on the preferences of passive consumers who pay or are willing to pay to avoid/mitigate the risk of extinction.
This research concept of biodiversity output refers solely to species threatened with risk of extinction [19] (pp. 41-45). The output of the biodiversity preservation service (the same threatened species may be contributing to other economic products, e.g.,: public recreation services, self-consumption of private amenities by the owners) relates to the wellbeing perceived by the passive consumers in the period, associated with avoiding and/or mitigating the risk of losing a biological species in return for their marginal willingness to pay a simulated additional consumer tax (ACT) and the total cost (TC) [20] (Figure 1, p. 4). ment and simulated exchange value (SEV) methods which provide the valuation of the additional marginal willingness to pay of passive consumers.
In this article our rSEEA is applied in an area defined by the map tiles of the Spanish Forest Map in which the predominant canopy fraction corresponds to Pinus pinea (SP), an area totalling 243,559 hectares of which 57% falls within protected areas and the remaining 43% in non-protected areas [18].
The biodiversity output (O) is estimated by aggregating the values of the additional consumer tax (ACT) marginal willingness to pay and the total cost (TC) of the biodiversity, representing the output of preserving the 104 wild biological species threatened with risk of extinction which are present in the protected and non-protected areas of the Stone pine forests (SPs) of Andalusia.
In the following sections of the article, we describe the concepts, methods, and results which explain the consistency of the results in terms of the economic rationale of the consumers and the government ecosystem trustee in the SPs of Andalusia.

Concept of Transaction Price of Biodiversity Output
This sub-section sustains the theory that biodiversity threatened with extinction can generate a demand function based on the preferences of passive consumers who pay or are willing to pay to avoid/mitigate the risk of extinction.
This research concept of biodiversity output refers solely to species threatened with risk of extinction [19] (pp. 41-45). The output of the biodiversity preservation service (the same threatened species may be contributing to other economic products, e.g.,: public recreation services, self-consumption of private amenities by the owners) relates to the wellbeing perceived by the passive consumers in the period, associated with avoiding and/or mitigating the risk of losing a biological species in return for their marginal willingness to pay a simulated additional consumer tax (ACT) and the total cost (TC) [20] (Figure 1, p. 4).

Figure 1.
Simulated market equilibrium output for threatened biodiversity. Notes: P* is demand and supply simulated market equilibrium price; O* is the price of the output that corresponds to the total amount of threatened species (Q*); PAC is government output average total cost; B is total operating benefit; PB is produced benefit; EB is environmental benefit; TC is total cost; IC is inter- Figure 1. Simulated market equilibrium output for threatened biodiversity. Notes: P* is demand and supply simulated market equilibrium price; O* is the price of the output that corresponds to the total amount of threatened species (Q*); P AC is government output average total cost; B is total operating benefit; PB is produced benefit; EB is environmental benefit; TC is total cost; IC is intermediate consumption; LC is labour cost; D is depreciation of manufactured (produced) fixed capital; and Q* is total number of threatened species.
The argument that the biodiversity output (O) cannot be valued as there is no equivalent with which it can be compared with to reveal its transaction price is incorrect and stems from this value being confused with its intrinsic value [19] (p. 27), [5] (Para. 6.72, p. 137). Thus, the price of the biodiversity output is the relationship of the exchange Land 2022, 11, 1119 4 of 21 decided by natural persons or institutions (in representation of natural persons) transferred reciprocally in the exchange in exclusive property rights over the biodiversity output and its consumption appropriated in return for real and/or simulated payment. The rationale behind why people can reveal/state a maximum price for the biodiversity demand is that in the future this species threatened with extinction can have a hitherto unknown use for humanity. A growing number of academics in social and natural sciences employ the term 'non-use' to refer to the passive uses of the option values among which is the biodiversity output; it is consistent to state the absence of a simulated transaction of something without human use. This is not the case of biodiversity as evidenced by the voluntary donations by people with the aim of preserving the threatened biodiversity of the planet [21]. This output of the threatened biodiversity is a passive consumption by people in addition to the passive output of the landscape conservation service (people's willingness to pay tax to avoid losses of non-threatened natural habitats) to which biodiversity contributes as a natural production factor of the cultural landscape.
The corollary of the above arguments is that the existence of a biodiversity demand function has the economic meaning of a transaction value when contrasted with the observed real or simulated acts of the passive consumers [20] (Figure 1, p. 4). The observed consumption is revealed in the voluntary contributions of the consumers to the economic units addressing the preservation of threatened biodiversity, the acceptance of public spending, and the additional payment towards the latter stated by the consumers in the surveys estimating the maximum marginal willingness to pay tax (e.g., choice experiment).

The Refined SEEA Output and Income Accounts for Threatened Biodiversity
The benefit of the threatened biodiversity at the scale of Andalusian forests is the same for all individual species, the forest area distribution of each of these individual species being where differences arise in this regard. The environmental benefit is obtained by subtracting the produced benefit from total benefit. The produced benefit is imputed according to a subjective real profitability rate of 3% of the government's public spending investment in the management of biodiversity for each type of forest at the scale of the micro-tiles of the Spanish Forest Map for Andalusia [18].
In countries with greater personal income levels the surveys gauging the opinion of the population reveal a general acceptance of current public spending on the preservation of habitats and wild species [22,23] (70% of Spaniards and 65% of Europeans consider that the destruction of natural habitats or the loss of animal or plant species is an "immediate and urgent" problem [22]). The government (acting as an ecosystem trustee) manages biodiversity by investing an operating total cost (TC). The biodiversity total cost in the rSEEA corresponds to the lower bound of the marginal willingness to pay tax revealed by the passive consumers. This assumption is based on the fact that it is the consumers who, through their votes, periodically endorse the programmes of environmental policies applied by the governments as part of their public spending actions in representation of the citizens ( Figure 1). It is necessary to estimate the upper bound of the marginal willingness to pay tax of passive consumers regarding the biodiversity output ( Figure 1, Table 1).
The standard System of National Accounts (SNAs) and SEEA estimated the threatened biodiversity output according to the total cost (TC) at purchase prices ( Table 1). The condition of the biodiversity output as a public service without market price means that the SNA assumed a value of zero for the simulated benefit (B). In this research the inconsistency of the SNA of imputing a value of zero to the B implicitly embedded in the output (O*) is avoided by simulating its exchange value through stated preference methods recommended by the United Nations in the SEEA guidelines [5]. Table 1. Key economic variable and accounting identity application of the refined SEEA in this case study on the existence value of threatened biodiversity in Pinus pinea forests of Andalusia.

Class
Acronym This Paper's rSEEA United Nations SEEA [5] Accounting Identity Output O Service of preserving wild species threatened with risk of extinction. It is valued by summing additional consumer tax (ACT) and total cost (TC). ACT is measured by a choice experiment survey to Andalusian households. TC is measured by biodiversity production function accruing from Andalusian government unpublished sources.
Service of preserving wild species threatened with risk of extinction is hidden in the government general production account of the System of National Accounts (SNAs). It is valued at total cost (TC).  Simulated benefit is valued at additional consumer tax (ACT) transaction price for Stone pine forests (SP) which the adult population of Andalusia would be willing to pay via an annual payment to avoid a one-species variation in the number of threatened species at the close of the period compared with the number at the opening of the period. Benefit is divided into imputed competitive produced capital benefit (PB) and residual environmental benefit of durable ecosystem asset (EB).
Rejects the existence of simulated benefit at transaction price for the existence value of threatened biodiversity [5] (para. 6.72, p. 137). The simulation of the upper bound of biodiversity output requires us to estimate the possible existence of a marginal willingness to pay additional tax (ACT) on top of the lower bound demand (TC) in return for avoiding/mitigating the future loss of species or an increase by one species in the number of species threatened with extinction at period closing.
In the Pinus pinea case study, the ACT of the biodiversity was firstly estimated (a mixed transaction value of area extent and biodiversity physical change values) together with the landscape conservation service using the choice experiment method and the transaction price of the ACT was determined using the simulated exchange value method [12] (Supplementary Texts S9 and S10). In accounting terms, the ACT corresponds, by definition, to the benefit (termed net operating surplus in the SNA and SEEA) given that the stated lower bound demand corresponds to the TC ( Figure 1, Table 1).
In this article we used information obtained from the choice experiment survey carried out in the Andalusian forest areas (AFAs) in 2010 [12]. An intuitive definition of the choice experiment applied is that the consumers are presented with a choice of preservation through the payment of an annual "fee" of their choice over a period of 30 years to ensure that the output of biodiversity does not decline (the number of species threatened or lost does not increase), to guarantee that the current situation is maintained, they pay an "insurance premium" as additional consumer tax (ACT) in order for the government to invest and therefore prevent the decline in the number of wild species in risk of extinction.
Consumers who stated a positive ACT AFAs wish to assure the future persistence of the species threatened with extinction according to some of the conventional degrees established by institutions and experts [24]. It was simulated that the ACT AFAs is raised through an annual charge (e.g., tax) to adult persons resident in Andalusian households. In return for this payment the consumers hope to avoid/mitigate a one-species increase in the number of threatened species (Q*), which stood at 224 recorded at the opening and closing of the 2010 period in the Andalusian forest areas (AFAs) [12] (Figure S12: Nonparametric function for revenue from landscape conservation and threatened biodiversity preservation) [24].
The ACT AFAs of the landscape and biodiversity are separated for econometric procedures [12] (Table S3: Extended production account of Andalusian forests). The simulated additional marginal willingness to pay for any individual threatened species s (ACTs AFAs ) is estimated assuming that all the species have the same transaction value in the AFAs as a whole. The simulated additional marginal willingness to pay per unit area of presence (As AFAs ) of the species s (ACTsa AFAs ) is estimated by dividing up the ACTs AFAs .
The ACTs SP of an individual threatened species s in the areas of Pinus pinea (SP) forest in Andalusia is estimated by multiplying its ACTsa SP by the area in which it has a relevant presence (As SP ). Finally, the estimation of the ACT SP of the quantity (Q* SP ) of threatened species in the Andalusian SP concludes with the summation of the individual ACTs SP of all the species: ACTsa AFAs = ACTs AFAs /As AFAs ACTs SP = ACTsa AFAs × As SP (3) Given the TC, and the ACT exchange values, the O* is estimated directly by aggregating these TC and ACT transaction values ( Figure 1, Tables 1, A1 and A2).
The refined SEEA (rSEEA) key concepts and accounting identities that make it possible to estimate the threatened biodiversity output are summarized in Table 1. The production and generation of income accounts estimate the gross values added (GVA) and net values added (NVA), respectively.
The production account for biodiversity registers the output including the final output consumed (FOc) valued at social price, defined as the simulated market price (FOc) and the own account manufactured (produced) gross fixed capital formation (GFCF) valued at the total investment cost price (TCi) ( Table 1): The final output consumed (FOc) of biodiversity demand estimates the output of each single species (not that of the overall individuals of each species) revealed/stated by the passive consumers who wish to assure their future persistence across the total area in which its presence is relevant [19] (pp. 41-45). The FOc originates in the enjoyment provided to the consumers associated with avoiding and/or mitigating the species extinction risk through their direct and indirect voluntary contributions via the ecosystem trustee (as the government institution that administers the biodiversity collective property rights, subrogated in the name of society as a whole). The FOc of the biodiversity is estimated by summing the ecosystem trustee ordinary produced total cost (TCo) and the passive consumers' marginal willingness to pay the ACT (Figure 1, Tables 1, A1 and A2).
Given the ecosystem trustee ownership condition of being a free access public service, the final output consumed (FOc) of the biodiversity demand can only be registered in the production account of the ecosystem trustee. The difference between the final output (FO) and the intermediate consumption (IC) provides the gross value added (GVA). The net value added (NVA) contains the operating incomes of the labour and the operating capital benefit termed net operating surplus (NOS) in the SNA and SEEA ( Table 1). The produced total cost (TC) incorporates the ordinary total costs (TCo) and the investment total costs (TCi). This circumstance means that the ordinary benefit (Bo) and the total benefit (B) coincide due to having assumed that the benefit (NOSi) of the GFCF is zero in the accounting period (Table 1).
The components of the B are the operating produced benefit (PB) of manufactured (produced) capital and environmental benefit (EB) of the ecosystem asset. The latter is called ecosystem service (ES) in the SEEA. A competitive real profitability rate (e.g., 3%) chosen subjectively by the analyst is imputed to the produced capital to estimate the imputed competitive PB. By subtracting the PB from the B, the residual value of the EB (or ES) is estimated directly, as long as the difference is positive. If not, then the B coincides with the PB and the EB has a value of zero (Table 1).

Rationale of Public Management of the Pinus pinea Forests of Andalusia
In Andalusia, the area occupied by habitats with the presence of Pinus pinea is currently at its historical maximum. Reforestations of Stone pine on the Atlantic coast have been documented going back to the early Middle Ages with the aim of generating intermediate service outputs to protect against the advance of moving dunes as well as the final output of wood supply for the fishing industry of the Atlantic coast [25]. In the last third of the nineteenth century and over the course of the twentieth century, governments in Spain adopted policies of reforestation in the form of pure stands as well as stands mixed with species of the Quercus genus and such policies have been continued over the past four decades by the government of Andalusia. Based on the new legislation relating to forestry and the protection of natural areas, the government of Andalusia has been pursuing policies to increase public areas and invest in forests since the1990 s. In this context, Stone pine is one of the native species of the genus Pinus with the greatest expansion [26,27].
Historically, the dominant final use of Stone pine forests has been the production of wood, charcoal, pinecones, game hunting, honey, aromatic herb essences, livestock grazing, and mitigating the advance of moving dunes on the Atlantic coast. Since the early 1990's the objectives of the Andalusian government policies have changed, adapting to market trends such as loss in commercial profitability of timber and the emerging final demand of consumers for public services of landscape conservation in Spanish and European society [22,23,28]. The management of Stone pine forests in Andalusia is currently orientated towards improving the production of intermediate and final services. Among the intermediate services are those of conservation forestry by non-industrial private landowners who thereby improve their enjoyment of the final consumptions of recreational hunting and private amenities. These public investments in conservation forestry normally involve agreements between the government of Andalusia and the private or public landowners [29]. The greater part of the investment in conservation forestry is undertaken by the government of Andalusia in public farms with the aim of maintaining and improving the final consumption of public services of the Stone pine working landscape [26].
The presence of Stone pine forests is currently documented in a given territory based on the criteria of spatial scale and dominance attributes of the trees in terms of tree density and age (see detailed technical report by the [26]).
In this case study research, we quantified the area of Stone pine in Andalusia based on map tiles of the Spanish Forest Map (MFE) and on the third National Forest Inventory (NFI). In this article the areas of Pinus pinea refer to those where it is the main species within the map tiles, either in the form of pure or mixed stands (Tables 2 and A1). The areas of Pinus pinea-dominated map tiles are classified into protected areas (SP PAs ) and non-protected areas (SP NPAs ). Pure stands account for around 50% of the area of Pinus pinea in non-protected areas while they make up less than 30% in protected areas (Table A1). Mixed stands of Pinus pinea, with one or two species of trees, account for 65% and 46% of the areas of the SP PAs and SP NPAs, respectively. Species of the Quercus genus predominate in the mixed stands, making up 40% in the SP PAs and 20% in the SP NPAs (Table A1).   (Tables 2 and A1).
The eight classes of protected area can be differentiated into three groups according to the level of intervention. The first is the national park, which includes in its management plan the avoidance of extraction by humans of live woody stocks and wild animals. The exceptions to this are those extractions undertaken for technical reasons associated with the management of wildlife compatibility, mitigating undesired damage due to competition, epidemics among wild species, and damage to the abiotic environment. The second is the natural park, with regulations that meet the requirements of the European Landscape Convention and which are aimed at the continuation of economic activities compatible with the persistence of wildlife and the natural environment [28]. In the six remaining categories of protected areas of Pinus pinea in Andalusia the regulations regarding economic activities are more permissive than in the case of natural spaces (Table 3). The new laws for protected natural areas in Andalusia incorporate silviculture aimed at the preservation of unique wild species of flora and fauna in danger of extinction risk as part of forest management in accordance with the European Union legislation and other international treaties on the protection of wildlife [24,30].

Economic Results for Pinus pinea Biodiversity
In this article we focus on the estimation of the existence value output, at the simulated transaction price, of the preservation service for unique wild species threatened with extinction risk in of the most valuable habitats in Andalusia, which is the Stone pine forest in protected as well as non-protected areas (Table A1).
Interpreting the comparative economic results for the threatened biodiversity of Stone pine forests in protected and non-protected areas of Andalusia is complex given the nature of the overall production and the subjective criteria adopted by an analyst in relation to the quantification of the passive consumers' scope.
Although the ownership of the SPs is distributed equally among the protected and non-protected areas, it is in the former that the government, through the ecosystem trustee, invests to a greater extent in management aimed towards the preservation of species in danger of extinction. The final output (FO) and the final output consumed (FOc) of the threatened biodiversity are 50% greater in the protected areas and the produced fixed investment (GFCF) is double that of the non-protected areas ( Table 4).
The additional consumer willingness to pay tax (ACT SP ) for the biodiversity is estimated for 104 species in their respective individual areas in the SPs (As SP ) in which they are present across the total of 243,559 hectares, this being the sum of the area of Andalusian map tiles with a predominance of Pinus pinea forest, 57% of which corresponds to protected areas (SP PAs ) and 43% to non-protected areas (SP NPAs ) (Table A2). Five threatened biological species in the SP PAs and nine in the SP NPAs fall short of an exchange value for the ACTs which is equal to or greater than one EUR per hectare due to their low As SP (Table A2). The ACT (which is equivalent to the net operating surplus) is 10% higher in the protected areas (Table 4). This difference in the values of the ACT SP between the SP PAs and SP NPAs can be explained based on the other associated vegetation in the map tiles dominated by the Stone pine forest, their specific locations, and the differences in the amounts of produced investment by the ecosystem trustee.
The government (ecosystem trustee) is directly responsible for the total cost (TC) of threatened biodiversity management. The three components of the TC, that is, intermediate consumption (IC), labour cost (LC), and depreciation (D) of produced durable goods (fixed capital) in the protected areas are 1.9, 2.1, and 2.6 times greater than those of the nonprotected areas, respectively. The own ordinary intermediate consumptions of services (SSoo) are of scarce quantity. The total cost (TC) for protected areas is 2.1 times that of the non-protected areas.
The net value added (NVA) of the protected areas is 1.4 times that of the non-protected areas. The incomes from labour in the case of the SP PAs are 2.1 times those of the SP NPAs . The operating benefit (B) is distributed spatially, the values depending on the amount of investment by the government (Figure 2). The produced benefit (PB) of the protected areas is 5.6 times greater than that of the non-protected areas, this being the reason why the environmental benefit (EB) coincides by chance for the SP PAs and SP NPAs of Andalusia in the 2010 period. Since the same species are present in both areas, the reason is that there is more public spending on preserving biodiversity in protected areas and therefore more produced benefit (PB) from produced capital and employee labour cost (LC).
The EB account for 42% of the final outputs consumed (FOc) in the protected areas and for 61% in the non-protected areas. The EB make up 50% of the NVAs in the protected areas and 69% in the non-protected areas.
The steady state situation in the number of the threatened wild species in the accounting period explains the fact that the capital gain value is close to zero, all else being equal. In this circumstance the net value added and the total income nearly coincide, as do the environmental benefit (ecosystem service) and the environmental income. Thus, in the Stone pine forests of Andalusia, the net added value is a measure of the total income from biodiversity, implying that sustainable management is achieved in both economic and biological terms. equal. In this circumstance the net value added and the total income nearly coincide, as do the environmental benefit (ecosystem service) and the environmental income. Thus, in the Stone pine forests of Andalusia, the net added value is a measure of the total income from biodiversity, implying that sustainable management is achieved in both economic and biological terms.

The Omission of the Benefit of Biodiversity in the SEEA Guidelines
The existence of a transaction price for the demand function of the final output consumed of biodiversity is rejected by some of the academic community and specialized statistical institutions such as the United Nations (see [5,17]) and academic authors (see [19]). The SEEA [5] relates the role of the biodiversity components to the condition of the natural production factors embedded in the nature-based outputs consumed in the present, apart from the existence value output: "the SEEA EA adopts the CBD (Convention of Biological Biodiversity) definition of biodiversity which recognises ecosystem, species and genetic diversity as the broad components of biodiversity. These components of biodiversity are not considered ecosystem services in themselves but there are distinct elements within these components that can be directly linked to ecosystem service supply" [5] (para. 6.60, p. 135). Thus, the SEEA focuses on the role of the physical accounts of biodiversity in order to provide information on the biological sustainability of ecosystem natural resource consumption in the period and simulated expected trends of future consumption: "the SEEA EA supports discussion on the link between biodiversity and economic activity and human wellbeing by providing a description of the relationships between ecosystems, the species that comprise them, and the SNA and non-SNA benefits that ecosystems provide" [5] (para. 13.41, p. 281).
The SEEA does not modify the SNA valuation of the output consumed of threatened biodiversity according to the purchased ordinary total cost (TCo) to the government [5,17]. Therefore, the SEEA omits the estimation of the benefits of existence value output of the threatened biodiversity embedded in the final output consumed (FOc): "while recognising the importance of genes and their diversity in underpinning ecosystem function and the flow of ecosystem services, the development of accounts for the genetic level of biodiversity has not yet been advanced. However, as data on genetic material for selected species becomes more widely available, the use of accounting to frame the connection to economic and human activity and wellbeing may be of relevance" [5] (para. 13.41, p. 281). The SEEA recognises an intrinsic value of unique genetic variety which, not being related to people, does not have economic exchange value: "the purpose in accounting for biodiversity includes informing conservation actions and the enhancement of biodiversity as an environmental management objective in its own right" [5] (para. 13.16, p. 277). However, the threatened biodiversity can have a hidden exchange value when human actions reveal/state a demand for the preservation of species. In this situation, while maintaining an intrinsic value for the ecologic functions, the human action here is aimed at satisfying the demand for final output consumption of the species.
The biodiversity output that counts is that which is motivated by the desire to assure its indefinite persistence, and this is linked to the critical stock of individuals in their natural habitat [31]. In the case of species where the number of individuals is maintained above the amount considered critical to reveal threat of species extinction, there is no biodiversity output. The SEEA recognises that "the relationship between changes in ecosystem extent and ecosystem condition and changes in the suitable habitat available for individual species or species extinction risk can be made explicit" [5] (para. 13.32, p. 279). This role of complementing the physical accounts of biodiversity excludes its biodiversity output incorporation in the monetary accounts of the SEEA: "species accounts can therefore readily complement the other information, especially concerning economic activity and human wellbeing in accounting for biodiversity" [5] (para. 13.32, p. 280).
In this article we argue that, apart from the contributions of threatened biodiversity to the environmental benefit embedded in other outputs recognised by the SEEA and generated in the ecosystem accounting area, it is consistent to measure the demand for threatened biodiversity output at the simulated demand transaction price. Consequently, we maintain that it would not be for reasons of inconsistency with the concept of income if the environmental benefit embedded in the final output consumed of threatened biodiversity were kept out of the monetary measurements of the SEEA.

Uncertainty in the Estimation of the Threatened Biodiversity Demand
The government-subrogated demand for threatened biodiversity includes the demand from the European Union consumers who "pay" for their consumption of the final output consumed of threatened biodiversity in the Stone pine forests of Andalusia through the European Community budget (e.g., Lynx pardinus L.). The difference between this lower bound (total cost) of the demand for biodiversity and the upper bound (output) of the demand from consumers in member states of the European Union was estimated in this research only as the additional willingness to pay additional consumer tax (ACT) stated by the adult population of Andalusia. The choice experiment survey carried out in the rest of Spain and four other European Union countries (own unpublished data) as part of the RECAMAN project [32]; the experiment on threatened biodiversity in the forests of Andalusia, uncovered positive marginal willingness to pay additional passive consumer tax (ACT), which confirms the benefits embedded in threatened wild biodiversity output not only in Andalusia but also the rest of Spain and European countries as a whole. The results obtained in this Andalusian Stone pine forests research regarding the total demand for biodiversity in Andalusia are conservative values and it is to be expected that given the global nature of threatened biodiversity preservation, the benefits perceived by the population concerned as a whole are greater than those estimated in this research stated by Andalusian resident households.

Towards the Management of Biodiversity Based on Economic-Environmental Accounting
Over recent decades, management by the Andalusian government has successfully maintained stability in the number of species in danger of extinction, although this situation may not be assured if the degradation of Pinus pinea habitats on the Atlantic coast persists. The challenge faced by the government regarding the sustainable management of threatened biodiversity in the Pinus pinea forests is that of implementing policies restricting the use of water for crop irrigation and land use changes on the Atlantic coast, such policies are being rejected by a large proportion of the local population. In this situation, in which there is a high risk of extinction of biodiversity, the government must address the probability of extinction as an unacceptable irreversibility based on the precautionary principle. If the government total cost of avoiding this irreversibility is tolerable to the society concerned as a whole, then it is licit for the government to take measures to avoid it, even though this can lead to a loss of income to current generations. The argument in this case is that it is the government, on the basis of the precautionary principle, and not the individuals who comprise the current generations, that is the guarantor of preserving the species legacy which must where possible be transmitted to future generations.
The custody of the threatened biodiversity by the government, having the attribute of subrogated exclusive property right over the final output consumed, is configured as an economic activity additional to other activities that may be generated in the ecosystem accounting area as well as beyond the area, to which the populations of wild flora and fauna contribute. It should be concluded from the arguments expressed in the above sections that, given the subrogated property and transmission rights of the ecosystem trustee (government as fiduciary of the legacy of threatened biodiversity), the existence value output of the threatened biodiversity meets the requirements of the exchange value as required in the economic valuation principles of our refined System of Environmental-Economic Accounting.
A part of the academic community and the statistical offices of the United Nations does not accept the simulated transaction price of the final consumed output of the threatened biodiversity preservation services. We show in this article that this omission is not based on the advances made in recent decades regarding methods of valuing public services without market prices. It is true that the measurement of the environmental benefit of biodiversity requires the conjunction of multiple methodologies and complex subjective modelling, the total cost of the production function, and the simulated demand of passive consumers. Intuitively explaining this complexity of measuring the benefit generated by the consumed final output of threatened biodiversity justifies the fact that certain assumptions and simplifications must be adopted in the reasoning and development of the non-market output valuation methods.

Conclusions
The results show that in the 2010 period no changes in land use or the number of threatened species were registered in the SPs. The estimated economic indicator values for the biodiversity are notably higher in the protected areas than in the non-protected areas, with the exception of the environmental benefit (ecosystem services). It should be noted that it is coincidental that the estimated values per unit area for the environmental benefit of biodiversity are the same for the protected and non-protected areas of the Andalusian SPs. It should not be concluded from this result that the ecological functions of protected and non-protected areas are also equivalent. While in economic terms the transaction price expresses the comparison of equivalence between the items exchanged as a single numeraire (e.g., monetary), this is not the case for biophysical functions of wildlife existence. Species need to feed, rest, sleep, nest, and protect themselves from predators, among other requirements, these necessities are not exchangeable (at least in their totality) in order to derive equivalent exchange value in a single numeraire. It would appear paradoxical that people are willing to pay more for the biodiversity of a protected area of Stone pine while at the same time the same residual amount is estimated to remunerate the ecosystem services in the protected and non-protected areas of SPs in Andalusia that they consume for free.

Data Availability Statement:
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to ownership rights.

Acknowledgments:
The authors thank the Agency for Water and Environment of the Regional Government of Andalusia for the financial and field work support for the REnta y CApital de los Montes de Andalucía (RECAMAN) project (Contract NET 165602), the Valoraciones de servicios y activos de AMenidades privadas de fincas SILvopastorales (VAMSIL) project of CSIC (ref.: 201810E036), and the Modelización de cuentas bio-físicas y Económicas de hábitats Costeros: estudios de casos de empresas Agrarias y Pesqueras en el suroeste de la península Ibérica" (MECAPI) project of CSIC (ref.: 202010E141). Isabel Martin and Luis Guzman at the Andalusian Environment and Water Agency (AMAYA) made relevant contribution to the field work of the RECAMN project. We acknowledge the contributions of Alejandro Caparrós, Paola Ovando, Eloy Almazán, and Begoña Álvarez-Farizo and other colleagues in the framework of the RECAMAN project for the methods and results presented in this article. We thank Adam B. Collins for the final English version of this paper.

Conflicts of Interest:
The authors declare no conflict of interest. Table A1. Map tile area with predominance of Andalusian Stone pine in protected (SP PAs ) and non-protected areas (SP NPAs ) (2010).