Forestry, from theory to practice: Central European ideas in native Patagonian forests in a context of climate change

José Omar Bava ^1* Marina Caselli ^1,2*

• ¹ Centro de Investigación y Extensión Forestal Andino Patagónico (CIEFAP), Esquel, Argentina
• ² National Scientific and Technical Research Council (CONICET), Buenos Aires, Buenos Aires, Argentina

In recent decades restoration, conservation, and sustainable forest management have been fundamental in mitigating global climate change (Zhang et al., 2021;Kauppi et al., 2022;Konstantin et al., 2022). Through sustainable forest management (SFM), mitigation can be extended by conserving carbon in forest products (Nabuurs et al., 2018;Verkerk et al., 2020;Tognetti et al., 2022;Loguercio et al., 2024). However, climate change affects the health of the forest and jeopardises the capacity of forest managers to achieve their objectives and meet forest-related needs of society (FAO, 2017), affecting SFM in many aspects, such as tree growth, tree mortality due to drought and heat, pathogen outbreak, and inducing changes in disturbance regimes, particularly fire (Keenan, 2015;Cailleret et al., 2017;Choat et al., 2018;Upadhyay & Tripathi, 2019;Kitzberger et al., 2022;Reiter et al., 2024).The new context has promoted an adaptation of traditional forestry towards a new forest management paradigm. While, in a general framework, traditional forestry has been based on simplifying forest structures and minimising or avoiding disturbances, the new paradigm highlights the importance of maintaining and increasing the variability of forest structures as a tool for ecosystem adaptation (Puettmann et al., 2009;Donoso, 2013;O'Hara and Ramage, 2013;Lafond et al., 2014;Isbell et al., 2015;Bowditch et al., 2020). This new approach requires monitoring forest functions and anticipating the effects of disturbances to carry out resilient actions that avoid negative consequences on forest services and productivity (Santopuoli et al., 2021;Tognetti et al., 2022). This can be done through nature-based solutions and close-to-nature silviculture (Brang et al., 2014), which are important components of climate-smart forest management, to increase timber production, adaptation, and mitigation sustainably.The forests of Argentinian Northpatagonia provide goods and services and contribute to the comprehensive development of the region. Their current distribution has been modelled mainly by anthropic fire at the beginning of the colonization of the territory (Veblen et al., 2003;Defossé et al., 2020), and was conditioned by the revegetation capacity of the species and the existence of fire refuges (Veblen and Lorenz, 1987;Kitzberger, 1994). Added to the risk of new catastrophic fires, north Patagonian forests under forest management are scarce, and some of them are subjected to extractive activities without planning, compromising sustainability and the forest's ability to adapt to changes (Grosfeld et al., 2019).The forest disturbances, whether natural or anthropic, interact with climate change, impacting ecosystems and the well-being of the associated populations (Suarez and Kitzberger, 2010;Amoroso et al., 2015;Rodríguez-Catón et al., 2016). Climate change strongly affects Patagonian forests, because biodiversity in the mountains, which includes exclusive species and a richness conditioned by small-scale environmental heterogeneity, is particularly vulnerable to rapid change (Tognetti et al., 2022;Adler et al., 2023). Since the late 1970s, the combination of fluctuations in oceanatmosphere climate variability patterns has resulted in warmer and drier conditions across southern South America (Garreaud et al., 2009;Jacques-Coper and Garreaud, 2015). Further, the climate change scenarios for this region predict a reduction in rainfall and an increase in mean summer temperature (DGF CONAMA, 2006). For this reason, in promoting SFM, it is crucial to maintain and/or improve forest resilience and resistance (Lloret et al., 2011;Tognetti et al., 2022).Northpatagonian forests also present a particular situation of demand for forestry production. Wood production from local native forests has historically been declining, and most of the wood comes from forests established more than 2,500 km away. From the point of view of the carbon balance, this demand could be better supplied with wood from the sustainable management of the local native forests, whose productive potential does not exceed 40% of the total forest area of the region. On the other hand, the lack of use pressure on the local wood resources can be considered an advantage for achieving SFM, taking into account the authorities' low capacity to supervise forestry activity.The objective of this paper is to propose for discussion the main features of a concept that critically considers the local conditions, both natural and socioeconomic, to promote a cautious use of the Northpatagonian forests in a scenario of uncertainty. The principles of sustainable management of native forests have been applied in Central Europe for more than 200 years (Burschel and Huss, 1997). Argentine and Chilean foresters, trained based on the Central European forestry school, were invited to adapt the Patagonian forests to silvicultural systems that were developed in Central European temperate forests (Martínez-Pastur et al., 2003), with similar dynamic processes, but with another framework. In north Patagonia most of the forests are in a natural state, therefore, the direct application of the same management practices perfectioned in Central Europe is not easy.The paradigm for the adaptation to Central European management systems is that the most cautious practice is to understand local natural dynamics processes and try to imitate them. However, the application of this idea should not only consider the ecological characteristics but also the socioeconomic system. There is a marked difference in the degree of anthropization between Central European and Northpatagonian forests. In Patagonia, we work in primary or secondary post-fire forests. So, in general, it is not possible to identify stands similar to those present in managed forests in Central Europe, as changes in the structure tend to occur along gradients. The socio-economic context for forest management in Patagonia is also different from Central Europe, especially in the institutional framework, the profitability of the system, the level of demand and technology, the idiosyncrasies of the actors, and the technical expertise. In North Patagonia, most forests belong to private farmers who, as a result of a new forestry law, since 2007 have to submit a management plan if it is intended to log their forests. They are generally livestock producers who have shown little or no interest in incorporating forestry into their productive system (Grosfeld et al., 2019). However, they may occasionally show interest in carrying out small forest interventions for one or a few years. In this case, the role of forest managers should not be to propose SFM in perpetuity at the property level, but rather, on the contrary, should focus on providing sustainability conditions for each of the isolated interventions, considering the forest potential at the landscape level.Furthermore, the challenge of climate change is inducing changes in the way silviculture is applied and in the objectives of forest management in Central Europe, mainly focused on a "naturalisation" of forest strategy (Gregor et al., 2022). However, worldwide climate change restricts the paradigm of imitating the natural dynamic of the forest through management. We can no longer know for sure what this "natural dynamic" is, since climate change modifies the type, frequency, and intensity of disturbances and, therefore, the dynamic processes (O'Hara, 2016). In this context, we, like Central European foresters, are forced to provide guidelines for managing and restoring forests in a framework of very high uncertainty (Lawrence, 2016;Tognetti et al., 2022), although starting from very different reference ecosystems and socio-economic conditions. The scarcity of demand for wood production in Northpatagonian forests can be seen as an opportunity, in the same way as the relatively close-to-nature state of most of the forests. Thus, it should be easier to move towards a sustainable management process if the wood demand is low and the forest structure is heterogeneous. Furthermore, certain processes and services are better preserved than in Central European forests, for example, the role of woody debris in biodiversity (Loguercio et al., 2019(Loguercio et al., , 2024)). Our efforts then, must be aimed at preserving these attributes while carrying out SFM for wood production.A reasonable recommendation for Patagonian native forests would be an adaptative management forest approach that minimises the changes caused to the forest. This approach has been applied in other parts of Europe, i.e. through Continuous Cover Forestry (Mason et al., 2022) and climate-smart forest management (Nabuurs et al., 2018). The selection of trees to be harvested and favoured must be adjusted to micro-scale structural variations, without attempting to homogenise the surface. This would give the forest greater resistance and resilience to disturbances (Tognetti et al., 2022). At the same time, part of the canopy should remain occupied by large ancient trees to maintain biodiversity (Ceddia et al., 2014) and improve microclimatic conditions by reducing desiccating winds. This entails an artisan selection and a very careful falling. This is feasible in low-scale productions of small farmers. This scale could be also well managed and supervised by the local forestry services.Besides, the duration of easily flammable seral stages of shrubland communities should be shortened with the rapid progression toward high forests (of greater carbon capture and stock) (Gowda et al., 2023;Loguercio et al., 2024), although preserving resprouting species as insurance for rapid recovery in case of burning. Managing forest disturbances, favouring resilient trees, implementing forest reserves, combining carbon storage, sequestration, and substitution, using forest bioenergy and wood for long-lived uses, and preventing land degradation by forest goods and services revalorization, must be our guiding light.As the demand for logging interventions comes from farmers who do not have long-term forestry plans, sustainability has to be considered at a forestry basin scale, using this level of planning to calculate the annual allowable cut rather than the property level. This requires broadening the knowledge about the structure, growth, dynamics, and possible responses to disturbances of our native forests, but mainly focusing on practice (Lawrence, 2016), carrying out silvicultural interventions based on this knowledge. That is, managing forests without having in mind a complete picture of the future or target forest. Therefore, it is necessary to have permanent monitoring systems that allow periodic analysis of the effects of interventions and their interaction with the climate, to make scientifically-based management decisions (Tognetti et al., 2022). This information could be obtained from a combination of remote sensing technologies, and through temporal and permanent forest plots. In this sense, some initiatives are starting to get underway, e.g. the recently created Forest-Climate Network of Argentina and the KLIMNEM project (Walentowski et al, 2020). However, there are only a few experiences of implementation of forestry schemes in experimental plots in Northpatagonia, much of them being successful but lacking continuity, which prevents detailed analysis, and makes scaling and planning at the landscape level difficult.On the other hand, some Northpatagonian forests have been gradually degraded due to deficiencies in the management of herbivory, unplanned forest harvesting, and large-scale fires, whose frequency exceeds that defined as natural. The environmental conditions for the recovery of these forests differ from the conditions in which they originated, so the success of the natural recovery processes is largely unknown. Since climate change continues and accelerates, probably in the most extreme conditions it will be necessary to perform active restoration, for which the question of the inclusion of exotic species and assisted migration remains open.So, we work in a different framework from Central Europe, and there are not enough experiences of successful adaptations in long-term forest management in North Patagonia, but as foresters, it is our task to continue learning from the challenges and take advantage of the opportunities. Climate change is here to stay and does not allow us to predict expected responses to our actions. The literature can guide us, but we must find the procedures that lead us to sustainable management (Burschel and Huss, 1997). The challenge of applying forestry adapted to Patagonian forest ecosystems opens up a range of possibilities and questions in the search for sustainability. Our efforts to deepen our knowledge of the functioning of these natural ecosystems and increase experimentation in managed forests will be the tools to make the right choices. Our goal will be to contribute to the maintenance and increase of the forest provision of goods and services, the use of wood for carbon storage, the revaluation of forests by landholders, and the restoration and conservation of forest lands for the good of all humanity.