The Role of Traditional Livelihood Practices and Local Ethnobotanical Knowledge in Mitigating Chestnut Disease and Pest Severity in Turkey

Abstract

The European chestnut population is enduring multiple compounding exotic pest and disease outbreaks across Turkey. The deeply held value of the chestnut species for the Turkish public is reflected in substantial government conservation programming. Chestnut is predominantly found on state land managed by Turkey’s General Directorate of Forestry (GDF), which generally upholds restrictive policies for chestnut-related livelihood practices other than nut collection and beehive placement. Such policies are justified by a government position that human activities and presence is likely to worsen disease dynamics. Conversely, a growing body of research findings testify that small-scale livelihood practices maintain biological diversity and, furthermore, that this traditional maintenance of diversity has been correlated with decreased pathogen pressure within agroecosystems. However, few studies have investigated this phenomenon in the context of agroforestry systems. At a global ecological moment of increasingly pervasive and severe exotic forest pathogen impact, this paper investigates the influence of diverse small-scale livelihood practices and knowledge on chestnut tree health across the highly heterogenous geography of Turkey. We conducted ethnobotanical questionnaires with 96 chestnut-utilizing households, and chestnut tree health evaluations in georeferenced forest areas they identified, throughout Turkey’s Black Sea, Marmara, and Aegean regions. Using data from 1500 trees, we characterized the effects of subsequently recorded environmental, physiological, and anthropogenic factors on tree health using multiple correspondence analysis (MCA), multiple factor analysis (MFA), and mixed models. Our results show that the traditional human management of tree physiology and ecology has a significant positive effect on tree health, especially through the acts of grafting and culling as well as the maintenance of diversity. We argue that conceptualizing such livelihood systems as human niche construction and maintenance can help forest management agencies to better understand and conserve valuable landscapes, even in increasingly common periods of severe pathogenic pressure.

Methodological advances for hypothesis‐driven ethnobiology

“…Multilevel models integrate different structures for random effects such as individual, crossed and nested structures as well as various types of models accounting for different levels of complexity including a random intercept, random slope, and both random intercept and slope models. For example, a nested random effect could arise from establishing plots as nested in sites (Wall et al ., 2019) or from genera nested within a given plant family (Bebber et al ., 2007). Another example is related to testing the theory of non‐random medicinal plant selection (Moerman, 1979; Ford & Gaoue, 2017; Robles Arias et al ., 2020; Muleba et al ., 2021).…”

Scaling Up Pro-Poor Agrobiodiversity Interventions as a Development Option

“…These families are generally not in a position to afford substitutes [4,19]. Farmers often use agrobiodiversity to manage risks because of limited access to agricultural inputs, such as pesticides, fertilizers, and irrigation systems [5,[20][21][22][23][24]. The use of diverse sets of crop varieties and livestock breeds has ensured sustainable production under conditions of unpredictable rainfall patterns, droughts, storms, and floods [4].…”

Understanding Tree Health under Increasing Climate and Trade Challenges: Social System Considerations

“…In these contexts, decision-making is likely to be reactive and based on experience. Wall et al [8] provide another perspective on forest governance with the example of local land managers in Turkey who grow chestnut (Castinea sativa) facing opposition to their practices on state-owned land [8]. Investigations by the authors found that traditional land management practices positively contributed to healthy chestnut populations, but these practices are treated with suspicion by state authorities.…”

“…Differing risk perceptions have led forest authorities to believe that human activity in the forests is negative instead of considering the positive roles that people play in maintaining forest health as part of their livelihood practices. Risk perceptions around practices such as grafting to increase commercial chestnut production have, according to Wall et al [8], impeded the growth of multipurpose community forest initiatives. They call for greater inclusion of local knowledge in forest management thinking and emphasise the contribution of traditional practice to creating resilient forests.…”

“…The authors suggest that in contexts where there are multiple and varied stakeholders, site types, governance models and levels of risk, an approach is needed that provides land managers with the flexibility to make their own decisions on risk rather than having to implement statutory requirements. As Wall et al [8] point out, there is some merit in trusting local land managers to make the right decisions about the trees they manage.…”