The cultural keystone species (CKS) concept (i.e. ‘species that shape in a major way the cultural identity of a people’ as defined by Garibaldi and Turner in 2004) has been proposed as part of a common framing for the multiple entangled relationships between species and the socioecological systems in which they exist. However, the blurred and prolific definitions of CKS hamper its univocal application. This work examines the current use of the term CKS to reconcile a definition and explore its practical applications for biocultural stewardship. We ran a search for the words ‘cultural’ AND ‘keystone’ AND ‘species’. Our search was limited to peer‐reviewed articles published in English between 1994 and 2022 (inclusive) and was conducted using Google Scholar, PubMed, Scopus and Web of Science. We extracted and analysed bibliometric information as well as information on (i) the CKS components, (ii) humans' support for CKS and (iii) the definitions of CKS. From the 313 selected documents, the CKS concept appears to be increasingly accepted, as evidenced by a growing corpus of literature. However, the absence of a systematic and precise way of documenting CKS precludes global cross‐cultural comparisons. The geographical distribution of authors using the concept is biased. We found that 47% of all the CKS reported and 38% of the works identified in our review were located in North America. Beyond ‘supporting identity’, several other of nature's contributions to people are associated with the CKS definitions. However, the contributions of the sociocultural group to the survival and conservation of the CKS (i.e. stewardship) are made explicit only in one‐third of the documents reviewed. To advance biocultural stewardship as a conservation paradigm, we suggest (a) defining CKS as an indissoluble combination of a non‐human species and one or more sociocultural groups; (b) acknowledging that species and sociocultural group relations should be classified in a continuum, according to gradients of relationship intensity; and (c) explicitly acknowledging the reciprocal relationships between sociocultural groups and species. Read the free Plain Language Summary for this article on the Journal blog.

The arrival and spread of chestnut blight, caused by the fungus Cryphonectria parasitica (Murrill) Barr, in Caucasian Azerbaijan has compromised the livelihoods of chestnut farmers and is causing rapid genetic erosion in the center of diversity for the European chestnut, Castanea sativa Mill. In Azerbaijan, blight was first reported in 2008 and is currently present in all chestnut-growing regions. Fortunately, there is a demonstrated biological control technique which may be applied in the context of Europe and Eurasia. This presents an opportunity to simultaneously achieve environmental and genetic resource conservation goals while reinforcing the livelihoods and maintenance of diversity of the nation’s chestnut growers. However, national institutions primarily recognize the economic and genetic importance of certain elite crops, particularly those which were prominent production goods during the Soviet period. The present work was undertaken to characterize the socio-economic role of chestnut production and use in the communities where this crop is grown and sold. We investigate the monetary role of chestnut sales in the livelihoods of growers and collectors. It is hypothesized that while continuing to be a minor production good nationally, chestnut sales in a newly entrepreneurial agricultural sector have taken on tremendous livelihood importance to specific communities. The socio-economic importance of chestnut-based income to Azerbaijan’s chestnut-growing communities is illustrated by the results of in-depth household budget interviews from 22 chestnut-growing households in two villages.

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.