Advances in Determining the Value and Importance of Useful Plants for Rural Populations in Santiago Del Estero, Argentina

The ecosystem services are components of nature, directly enjoyed, consumed, or used to yield human well-being [1]. Medicinal plant species constitute an important alternative to conventional medicine in a large number of developing countries, especially within poor communities that inhabit rural areas and lack access to health services [2]. Similarly, plants provide extra food supply for people living in poor regions. Nonmarket valuation, and other economic techniques that emphasize exchange values over cultural and ecological values, have been subject to criticism regarding the inability of exchange values to represent the total value of an ecosystem [3]. Many of these forest goods and services do not have a market price to reflect the benefits they provide to society. While several goods such as timber have market prices, or are at least partially traded in the market (such as game for hunting), most forest services are generally non-priced public goods (leisure and recreation, watershed protection, biodiversity, etc.) [4]. Especially in the context of the valuation of ecosystem goods and services, this is an unjustified oversimplification, as there are often trade-offs between the short-term and long-term use of nature. Thus, a suitable valuation method has to take into account irreversibility and long-term consequences. As a consequence, values are not static but dynamic and depend on the co-evolution of the three subsystems nature, economy and society [5]. Bruno and Sarmiento [6] investigated the economic dependence of people who inhabit forests with their services. Studies of indigenous and popular knowledge about natural resources are becoming increasingly important in defining strategies and actions for the conservation or recovery of forests. The key role of indigenous and local knowledge in biodiversity conservation and management has been consistently highlighted within many international directives [7]. The use of plants and plant products for different purposes such as food, wood, medicine, fiber, oil, fodder, aroma and ornament could be traced as far back as the beginning of human civilization [8]. Crimson Publishers Wings to the Research Research Article


MCDA.000642. 6(4).2020
Others studies on medicinal plant use have been conducted in several localities in Santiago del Estero, northern Argentina, by Díaz [9], Sarmiento et al. [10]. Regarding useful plants for food, Sarmiento et al. [11,12] published studies on consumers' tastes and preferences. He also did research on the knowledge of native forest food products in urban populations. The properties of dye plants were valued by Sarmiento and Guerrero Maldonado [13]. These studies and research were carried out within a thematic network of medicinal, aromatic and dye plants in northern Argentina, coordinated by Arraiza et al. [14]. Under the Ecosystem Services approach, ecosystems are considered to be important because of the multiple values they offer. They provide individual utility and economic development (i.e. instrumental value), help to build meaningful relationships between humans and nature (i.e. relational values), and serve as ends in themselves (i.e. intrinsic values) [15][16][17]. Therefore, ES valuations are crucial since they attempt to reflect these multiple values [18].

Objective
The objective of this paper is to examine the studies about valuation of ecosystem services provided from useful plants in Santiago del Estero, Argentina and to determine information gaps on this topic.

Material and Methods
The study was conducted in different rural areas in the province of Santiago del Estero. The province has a population of 874,006 inhabitants [19] and covers an area of 136.351km 2 , in northwestern Argentina. The study area lies between latitudes 20° to 30°S and longitudes 62° to 66°W. The inhabitants are mostly rural people with low incomes and far from major urban centers. Productive economic activities aimed at low-scale subsistence are predominant in most of these areas. Surveys were conducted personally and individually on a population accessed at random in the locations described, and trying to cover as many families as possible. In all the study cases the Contingent Valuation Method was applied. A similar survey was applied in all the sites studied. In the case of medicinal and aromatic plants, 17 surveys were performed in Santos Lugares, 30 surveys in Guampacha and 80 surveys on a sample population within the 18-82 age range, being women the majority [9,10]. Regarding dye plants, the sample population to which the survey was conducted was composed of thirty-five (35) people in the 16-78 age range, and corresponding entirely to women (no man was found dedicated to the craft with sheep wool or to the collection of dye plants) [13]. Between 2017 and 2018, the provision of food plant in others parts of the province were valued [20] with Contingent Valuation Method in 111 cases.

Result and Conclusion
Regarding medicinal species, there are only two other studies in the province and correspond to the western area departments. This work was the first carried out in the sampled areas and the results can be compared with the ones obtained in other studies and will help expand the database in Santiago del Estero (Table 1). Regarding plants for medicinal purposes, of the total respondents, 97.5% obtained them directly from the forest. In addition, 65% said to have cultivated a plant in their garden. Most people obtain the plants from the forest or grow them in their garden. The importance of the natural environment for these people as a source of alternative timber resources is demonstrated. The results can be the basis for researching the development of potential markets of medicinal plants in the region, as Khan and Abdur [21] comment. More research on the use of aromatic plants in Santiago del Estero should be done since there is no research results related to the valuation of aromatic plants in the province. Regarding dye species, there is no history of research in the province.

MCDA.000642. 6(4).2020
This document is the first of its kind in this area. The importance of the implementation of the method and the value found can generate future applications in similar situations. In Salta, Argentina, Lambaré et al. [22] studied and compared the use of dye plants between 1994 and 2000 with those in 2007 and 2008. They also analyzed the current factors in the acquisition and transmission of knowledge related to such use. In relation to rural people's perceptions of the value of natural resources, the healing uses they give to medicinal plants have become a natural heritage they are willing to protect and preserve for future generations. As for the economic value expressed in monetary terms, the environmental service of the plants studied represents money that people avoid spending on medical services due to the free availability of medicinal plants. If the values of Consumer Surplus and Surplus Compensatory calculated for the WTP and WTC are contrasted, it can be noted that the values obtained are very similar for both, although slightly higher than those calculated for WTA and WTP. Regarding food plants, there is no history of research in the province. This document is the first of its kind in this area. In view of the trends to value ecosystem services, it is necessary to find other values of ecosystem services such as the conservation of biodiversity, carbon capture or water quality in the region.