Ecosystems, their components, processes and functions are all subject to transformation or management by local populations. Traditional ecological management is understood to be a set of interventions and transformations which are the result of community decisions regarding the natural and artificial systems, with the explicit purpose of adapting the landscape to make it more habitable and ensuring the availability of certain natural resources (Casas et al., 2014). According to Toledo et al. (2003), resource management is an adaptive response to the uncertainty of their availability. It is part of the human desire to domesticate or control whatever is affected by this condition of uncertainty, so as to ensure the continuation of social and cultural life (Blancas et al., 2014).

The subject of landscapes as biocultural systems has been studied widely over recent years (Berkes et al., 2000; Miller and Davidson-Hunt, 2010; Casas et al., 2014; Lins Neto et al., 2014). They are considered as physical spaces which reflect the use, values, learning and cosmovisions of the societies inhabiting them over time (Capparelli et al., 2011; Castro et al., 2012), and they also acquire a symbolic character as they are accorded significance by the different cultures (Greider and Garkovich, 1994; Boillat et al., 2013; Fernández-Llamazares et al., 2016).

The landscapes have been, and still are, constantly changed by their human inhabitants, leading to processes of domestication through both individual and collective subsistence practices which are reproduced and recreated in a dynamic way. This leads to socio-environmental constructions impregnated with everyday experience, in a permanent state of adaptation to the surroundings and their changing conditions (Berkes and Davidson-Hunt, 2006; Haber, 2006; Kareiva et al., 2007; Castro et al., 2012; Lema, 2014). It is currently considered that the study of these practices in contexts that have undergone processes of change represents a key way of understanding the value of resources and their potential conservation (Washington, 2013; Blancas et al., 2014).

Local strategies for managing certain space-time resources depend on perception of which resources are useful and can be taken advantage of and preserved, and which are not, according to the necessities and perspectives arising over time among the population (Blancas et al., 2014). Shaanker et al. (2003) highlight that locals' ecological knowledge may have important implications for the long term conservation of plant resources, and that communities with a greater degree of this knowledge might be more “prudent” in their use of the environment, through adoption of less destructive harvesting practices, particularly when economic interests are affected, and even when being “prudent” implies poorer short term returns.

The study of the body of fuelwood knowledge which forms part of the accumulative cultural heritage of local communities, referred to conceptually as traditional ecological knowledge (TEK) (Berkes et al., 2000), may contribute to the construction of perspectives on the sustainable management of these ecosystems. This involves in-depth study of the knowledge and practices associated with use of the environment, which are related to the maintenance of ecological cycles, and therefore ensure sustainability, thus making possible the coexistence and even the evolution of inhabitants along with their natural resources (Berkes et al., 2000; Shaanker et al., 2003; Berkes, 2004; Tiwari et al., 2010). Despite the progress made in this subject with regard to the use of firewood (Cardoso et al., 2012, 2015; Arre et al., 2015; Morales et al., 2017), the processes associated with domestication of the arid cultural landscape leading to the promotion and supply of these scarce resources are still unknown. The studies refer mainly to firewood extraction as a destructive practice that shows little care for the environment or resource renewal (Tabuti, 2007).

Among the practices of anthropization of the environment, the ex and in situ management of vegetation (Casas et al., 2007, 2008, 2014; Lins Neto et al., 2014), control of ecological succession, diversion of watercourses and the gathering of useful plants (Davidson-Hunt and Berkes, 2003; Molares and Ladio, 2009; Pirondo and Keller, 2014), have been mentioned as strategies which increase the supply of species of interest and reduce the uncertainty of their availability throughout the year and in succeeding years (Barrera-Bassols and Toledo, 2005; Molares and Ladio, 2009). For example, taking advantage of ruderal and exotic species that appear rapidly on land where clearings have been produced by disturbances of moderate intensity is a practice shared by many cultures (Molares and Ladio, 2014).

The species diversity constructed through different management practices may be taken advantage of in different ways, utilitarian versatility being considered as the sum of the different uses presented by a certain resource. It has been found that the species with highest use consensus in these societies often present high utilitarian versatility, a pattern based on profound knowledge of the best-known species, which promotes caring attitudes, since the people value the potential of the species in a holistic way (Richeri et al., 2013). Studies performed on medicinal plants have shown that plants native to a certain place generally offer greater use diversity than exotic species, due to the longer period of time they have been in contact with local populations (Molares and Ladio, 2009).

Since ancient times indigenous communities in Patagonia have bonded with the resources in their environment, which has not only allowed them to develop a deep knowledge of nature, but has also favored the creation of diverse landscapes with different levels of domestication (Ladio and Molares, 2014; Sedrez dos Reis et al., 2014). These communities have viewed nature as a fundamental part of their life system. In particular, the Andean environment, across its entire altitudinal gradient, is taken advantage of as a source of natural resources through different gathering practices, although practices tending toward tolerance, facilitation and promotion are also observed (Ladio and Molares, 2014), generating a gradient/continuum of landscapes with different levels of human intervention. These spaces were, and still are, valued differentially according to their vegetation and geomorphological characteristics, as well as their utilitarian and symbolic attributes (Ladio and Lozada, 2003, 2004; Ladio et al., 2007).

The gathering of woody species for fire is a subject of great socioeconomic relevance on a global level (Tabuti et al., 2003; Chettri and Sharma, 2007; Ramos et al., 2008) and as an area of study, considering the cultural value of heating by firewood, the severity of winter at this latitude, the scarcity of available petroleum-based alternatives, and their high cost (Cardoso et al., 2012). As a result, most households, and the rural or semi-rural ones in particular, depend principally on plants for cooking and heating (Cardoso et al., 2012; Arre et al., 2015). Recent ethnobotanical studies in Patagonia have documented consumption patterns of firewood species, the attributes of the wood, and preferences shown by locals, oriented mainly toward native species (Cardoso et al., 2012, 2013, 2015; Arre et al., 2015) and the new practices employed to counteract scarcity of the firewood resource, such as the use of exotic species of more or less recent appearance in the region (Cardoso et al., 2017). This evidence reflects constant processes of hybridization of knowledge, which make possible the incorporation of new woody elements to compensate for deficiencies (Cardoso and Ladio, 2011).

The objectives of this work were to analyze the gathering patterns of firewood plants and their relationship with the different domesticated landscapes that form part of daily life in two rural communities of the Patagonian steppe. Our questions are: (1) whether environments with a lower level of landscape domestication are used more intensively for firewood gathering, in terms of species richness and use consensus. (2) whether in these environments with a lower level of landscape domestication a higher proportion of native species are gathered, and a higher number of species that were used in the past. (3) whether in these environments with a lower level of landscape domestication the woody species are used in a more versatile way.

Our results show that the landscapes with a lower level of domestication are not the most intensively used, not in terms of number of species, use intensity or species with higher use versatility. For the two communities living on the Chubut steppe, gathering patterns of firewood plants depend entirely on landscapes with different levels of domestication, which are used in an articulated way. This gathering pattern is dynamic and possibly evolves with the changes that come about in the landscape and other factors such as livestock breeding. All these environments created according to the needs of locals are used in a complementary way, possibly indicating “prudent” (Shaanker et al., 2003) and diversified use of these resources, so that the impact of gathering is distributed across the entire environmental gradient (Cardoso et al., 2017). This reflects an integrated concept of the landscape, as has been widely documented for different traditional peoples in Argentina (Crivos et al., 2004; Pirondo and Keller, 2014). In other words, the landscape units present spatial continuity in response to ecological gradient, type of management and the multiple interconnections generated by the inhabitants and their domestic animals, all of which is accompanied by global exploitation (Capparelli et al., 2011; Molares and Ladio, 2012, 2014).

The communities of Costa del Lepá and Gualjaina obtain in total 28 different firewood species, a richness similar to that registered by Cardoso et al. (2012), who recorded 27 species in other rural zones on the Patagonian steppe. This richness is the result of diverse use of the landscape and the integration of new supply strategies, such as purchase and social welfare plans (Cardoso et al., 2013). The species are shared little between environments, considering the intentional addition of exotic and new species in the most domesticated landscape, mainly for firewood purposes. However, the low diversity of species in these environments (10 species) coincides with domestication patterns that tend toward a reduction in the number of species, monoculture and specialization of species (Amico, 2002). The three types of environment analyzed showed no significant differences in the proportions of native and exotic species gathered, indicating that gathering pressure is shared between the different landscapes. Nevertheless, the multinomial analysis showed that the probability of collecting native plants is 100 times higher in environments with low domestication, while the reverse is true for exotic species. The inhabitants have incorporated a high proportion of exotic species through cultivation, in addition to those species which have begun to grow in the wild. This could be favored by the decreasing availability of native resources and the strong influence of external government organizations which provide technical support that promotes the incorporation of exotic resources (Eyssartier et al., 2013). The use of exotic species in domestic landscapes in Patagonia and other regions of the world has been highlighted by several authors to be a local solution to various needs, since in general they are easily available, fast growing, and more tolerant than native species (Eyssartier et al., 2009; Dos Santos et al., 2010; Richeri et al., 2013; Rovere et al., 2013), in addition to complementing native species, covering new needs, and diversifying the offer of useful plants (Albuquerque, 2006; Medeiros, 2013; Ladio and Albuquerque, 2014).

The semi-domesticated landscape, which includes mainly river valleys, with an intermediate level of human intervention, was also a significant site for the gathering of firewood. In these environments the species richness of native plants gathered is higher than that of exotics, although the latter are the most used. The more frequent use of the exotic species may be associated with their abundance, accessibility and quality, as observed in other studies (Albuquerque et al., 2009; Cardoso et al., 2012). One notable example of this is Salix sp., an exotic species of rapid growth that quickly colonizes and becomes established on most Patagonian riverbanks, in many cases displacing the native species S. humboltiana, and competing successfully for resources and suitable regeneration sites (Bozzi et al., 2014).

In contrast, the landscapes where there had been relatively little anthropic intervention presented the greatest number of cites for native firewood plants (100 times more than the most domesticated environment). Previous investigations carried out in similar environments in Patagonia have highlighted the important use of native species for firewood, compared to exotics (Cardoso et al., 2012). Schinus johnstonii is the most frequently gathered resource in this landscape. The cultural importance of this species over time has been documented in archaeobotanical studies and in recent work in the region, highlighting this species' characteristics of high calorific value and long-lasting embers (Ancibor and Pérez de Micou, 1995; Cardoso et al., 2013; Morales et al., 2017).

The results also indicate that there is no variation in pattern of use of the landscape in terms of use versatility, and that in general terms the combustible plants are not very versatile, possibly due to their fuel uses (heating and cooking) being prioritized in the interview. Even so, it must be mentioned that the firewood plants, as well as providing energy, are a source of animal fodder, are used in making shelters for the animals and in construction, as also found by Cardoso et al. (2012) and Morales et al. (2017). These authors highlight the fact that the introduction of rapidly growing exotic firewood plants in peri-domestic areas increases the richness of uses of the flora, revealing mechanisms that improve inhabitants' self-sufficiency.

It is interesting to note the dynamics of use of the different landscape areas over time. According to informants, during their infancy the semi-domestic and low anthropic intervention environments were of more importance for plant gathering than they are now, given their higher offer of species with high calorific value. At the present time, the extraction of firewood is affected by the work of large livestock companies, as well as the increasing problem of desertification due to overgrazing, amongst other factors, which cause damage to the soil and plant cover. These phenomena gradually configure a new landscape, thus generating the need for new strategies to obtain supplies (Marconetto, 2006).

Analysis of the interviews reveals that historically, the purchase of firewood species was infrequent in the studied communities, as was the use of gas. It has been recorded that half the population now buys firewood plants, mainly N. antarctica, which comes from the Sub-Antarctic Forest, and is one of the most commonly used and most commercially exploited species (Arre et al., 2015). The current tendency to purchase firewood, as a provision strategy, has also been observed in other rural communities (Ramos et al., 2008; Cardoso et al., 2012); in this way the factor of uncertainty in the availability of these subsistence resources, as conceptualized by Blancas et al. (2014), is decreased.

Together with the preferential use of species adapted to the disturbances typical of these environments (e.g., fires, overgrazing) (Morales et al., 2017), this suggests an articulated, dynamic system in which processes of climate and socio-political change (decrease in precipitation, mineral extractivism, etc.), flora and populations all coevolve. Thus, complementary use of the landscape, selection of species that grow quickly after harvesting and innovation in supply strategies (purchase), understood as local responses to the problem of change (Ladio, 2017), promote faster recuperation of the landscape and woody species, decreasing uncertainty and increasing biocultural resilience (Ladio, 2017; Morales et al., 2017). For example, some informants revealed that since many people have started buying firewood, regeneration of native plants such as Retanilla patagonica has been observed. This moment in the collective memory of the studied populations marks the beginning of an indirect process of promotion of the availability of this species, so that it can be used in the future; this is, therefore, management that will promote domestication of the environment.

Firewood gathering has always been stigmatized and associated with practices considered as destructive, and carried out by poor communities. In our case study visibilization of the firewood gathering practice from the perspective of landscape domestication allows us to reveal more complex, integral processes. Although native plants are much used and obtained from environments with a low level of domestication, inhabitants do not seem to concentrate their efforts on those environments alone. Medium and high domestication level landscapes contribute exotic (and native) plants which play a substantial role, alleviating use pressure on native species, and while this cannot prevent over exploitation, it does minimize it. The continuity of use of wood for combustible purposes is also favored, guaranteeing a supply of this resource, fundamental for subsistence, and an important component of the locals' lifestyle. Complementary use of the landscape is the underlying logic, but the incipient domestication of species present in the totally domesticated environments is also an interesting aspect that should be studied in more depth. The growth of these plants (10 species) is being encouraged with irrigation, thermal and wind protection, pruning, the adding of organic material from home composting, etc., which generates greater production of firewood and reduces impact in terms of extraction of native species.

In the arid region of Patagonia significant effects are expected in the coming years, in association with global climate change. These changes will no doubt affect the communities whose subsistence depends on their close bond with the landscape and its resources (Rabassa, 2010). Within this scenario it is essential to review government strategies and conservation plans, which are always top-down. The inclusion of bottom-up perspectives on the subject of firewood is necessary in order to find solutions that take local management and cosmologies into account in an inclusive way (Ladio, 2017). Our empirical information reveals that the inhabitants of Patagonia are creating new environments with richness and versatility of use, and seeking new alternatives in the face of firewood scarcity, through landscape domestication.

AL and SM conceived of the study, designed the questionnaires, participated in data analysis and performed statistical analysis. DM carried out questionnaires among the Mapuche communities, analyzed the tales, performed statistical analysis and drafted the manuscript. The three authors read and approved the final manuscript.