Subsistence of Mesoamerican human peoples has been characterized by a strong relation with their neighboring natural resources and ecosystems. Evidence of such relation are the more than 6000 plants species that are currently used to satisfy a broad spectrum of needs . Nearly 1000 of these plant species are managed with different practices and intensities, and some 200 have clear signs of domestication [1–3]. Plant management practices and their intensity are guided according to human purposes and needs, and according to socio-cultural and ecological contexts [2, 3]. Some practices are usually aimed to ensure or increase the availability of a particular resource that is scarce, and others to promote particularly attractive variants within populations [3, 4]. Similarly, some plant resources have low importance, while others are particularly relevant not only in people’s subsistence but also as elements of their cultural identity. Among the latter relevant species maize, beans, chili peppers and squashes can be mentioned as the more representative in Mesoamerica , but others, nearly 100 to 200 plant species play important cultural roles, among them agaves have a special place. Studying the factors that currently influence decisions of management and domestication is particularly important in an area that has been recognized as one of regions of the world with the earliest signs of domestication and agriculture [2, 5, 6]. In addition, since these processes are continual and on-going, understanding them allows establishing viable bases for technological innovation for sustainable management of natural resources and ecosystems, one of the main current challenges of humanity .
Agave species have been important edible plant resources for Mesoamerican peoples since prehistory [5–7], and currently are used to satisfy multiple needs such as food, construction materials, fibers, beverages, living fences, medicine, tools, and religious ceremonies, among others. The relationship between agaves and humans has been cardinal to Mesoamerican cultures for whom agaves were in the past represented as deities and currently continue being part of their worldviews [8–12]. Most of agave traditional uses remain alive, especially in rural communities, where they represent not only a complement to the household’s subsistence, but in some cases the main or the only source of monetary incomes [5, 6]. The current activity that represents by far the main source of incomes from agaves is the traditional production of the distilled spirits called mescal, which is carried out by peoples of 24 (from a total 32) Mexican states and involves at least 53 agave species [11, 12]. The majority of these species are harvested directly from wild populations and there is scarce information about the existence or not of practices aimed to prevent their depletion. According to [12, 13], some few species are in situ managed and some others, even fewer, are cultivated ex situ with clear signs of domestication [7, 8].
During the last decades, regional, national and international demand of mescal spirits has pronouncedly increased, a phenomenon called the “mescal boom”. Currently, only eight states of Mexico have been recognized in the mescal’s appellation of origin (“Denominación de Origen Mezcal”, DOM, for its acronym in Spanish), among them the state of Michoacán, in which 29 municipalities received their recognition as part of the DOM in 2012. This fact increased the regional, national and international demand of Michoacán’s mescal, which has influenced an increasing pressure on wild populations of several species as well as on the few agave crop species used for this activity.
According to Gallardo et al. , the mescal production in Michoacán has a tradition of about 400 years old. Five Agave species are used for such purpose: Agave tequilana Web. and A. americana L. var. subtilis (Trel.) Valenz.-Zap. & Nabhan, which are domesticated species and exist only under cultivation, as well as A. angustifolia Haw., A. cupreata Trel. & Ber., and A. inaequidens ssp. inaequidens Koch. These species grow wild in the regional forests, although some communities have started to cultivate them in the last 20–25 years. Local governmental programs enhance mescal production and contribute to make it a growing activity, promoting its commercialization and exportation. However, they have forgotten the need to assure a sustainable provision of the mescal raw matter. The traditional mescal producers led by the market demand, have exceeded their traditional small production capacities, causing over-extraction of their wild and cultivated resources, as well as of other essential materials necessary for mescal production, particularly fuelwood and spring water. Governmental programs do not take into account neither issues of resources supply, programs and regulations of management of wild agave populations, nor the establishment of agaves and woody species plantations. This situation seriously endangers the wild populations of agave, the forests they form part, and the sustainability of this important socioeconomic activity. Therefore, social-ecological studies for establishing the bases of a long-term sustainable production are a priority in Michoacán and other areas of Mexico.
Some studies have documented cases of local extinction and endangered populations of wild Agave species related to the lack of management strategies in territories of mescal producing communities. These are for instance the cases of Agave potatorum Zucc. in the Tehuacán Valley; and Agave cupreata in the Balsas River basin [9, 10, 12, 15–17]. These semelparous species reproduce only by seeds  and like all mescal agaves, they are harvested when mature, just before the flowering stalk starts to develop, thus cancelling their only chance of sexual reproduction. The sexual reproductive event may take place when agaves reach about eight to 20 years old, a period varying among species, varieties regions, soils, and shade. With some important exceptions, the apparently prevailing extraction pattern of wild mescal agaves in Mexico is to collect all the reproductive individuals existing in a site and wait for the younger agaves to start flowering for cutting them. This practice, which is even more common as the demand of mescal increases in markets, modifies the natural demographic cycle of agaves thus surpassing the recovery capacity of populations.
As we examined previously in the case of A. potatorum [9, 10, 12, 15], the risk to local extinction of wild agave populations is determined by a complex relationship between distribution, abundance, reproduction type, length of life cycle, the intensity of extraction, which is in turn related to the demand of mescal in markets. But importantly, the risk also depends on the occurrence or not of practices directed to prevent the impact on agave populations. The risk should be visualized in two important dimensions, one is the probability of losing the populations of plant resources, and the other, the consequent probability of losing the socio-cultural and economic activity that mescal production represents for people.
Management may include regulations, planning, and actions directed to maintain populations and recover those decimated or extinct [5, 6, 8, 12]. As Gonzales-Insuasti et al. [18, 19], Arellanes et al.  and Blancas et al. [3, 13] documented, management responses are influenced by multiple factors related with socio-cultural, economic, ecological and availability pressures. Considering these studies, we hypothesized that similarly as in other species that are non-timber forest resources, in A. inaequidens we would find that the greater the risk the greater the management responses by people; but, alternatively, in situations in which no management is practiced, the greater the risk the greater the probability of agave populations depletion and eventually local extinction. Unfortunately, the latter situation is probably the most common and its characterization could help to identify the priority areas for protection, conservation and restoration activities, in order to construct sustainable forms of managing these plant resources.
Particularly important in this study was documenting the management strategies that are being designed and constructed by local people to decrease the risk of A. inaequidens. These strategies involve expressions of traditional ecological knowledge (TEK) on the target species and the ecosystems it belongs. In addition, the management techniques available may potentially help to implement them in the critical areas where the species is in high risk of disappearing. The different experiences of management practices are also expressions of different social and ecological contexts in which the risk of agaves and the management responses occur. Comparing those situations may allow understanding the context in which management techniques are being constructed, which in turn would help to provide criteria for planning innovation in the multiple contexts in which A. inaequidens is used to produce mescal. Interchange of experiences of management strategies between communities and agave handlers is, therefore, an attempt to construct a catalog of technical alternatives for a more rapid response to a problem that, because of the rhythms of markets, is now surpassing the rhythms of technical innovation in traditional contexts. Our study aims to contribute to document local management strategies and to develop proposals for research, actions, and responsibilities to implement by coordinated actions among producers, government, NGOs, and the academic sector.