The term “biocultural” was first applied to the field of anthropology in the 1970s (Wiley and Cullin 2016), where the meaning of “biocultural” in this field was the sociocultural and environmental influences on human biology (McElroy 1990). Later, through the joint efforts of ethnobotany, ethnoecology, and other disciplines, the term “biocultural” was no longer limited to independent biodiversity or cultural diversity but emphasized the interactions between the above two. Researchers from a wide range of disciplines, including biology, anthropology, sociology, botany, geography, and especially the related practice disciplines of planning and landscape architecture, have expanded research related to biocultural topics (e.g., biocultural adaptation, biocultural evolution, biocultural model, biocultural predictors, biocultural sciences and biocultural diversity) (Baltes and Singer 2001; Bates et al. 1993; Goodman et al. 1988; Luz et al. 2018; Msaidie et al. 2011). Biocultural diversity (BCD) has become an interdisciplinary field combining natural and social sciences, linking linguistic diversity, cultural diversity, and biodiversity worldwide (Maffi 2007). They form an important part of the world map of diversity studies.
In general, BCD research has examined multiple perspectives within multidisciplinary intersections, such as the shift from biodiversity to biocultural diversity and the development of biocultural diversity from a concept to a global practice. Specifically, the shift from biodiversity to BCD has been facilitated by the expansion of research horizons in biology and interdisciplinary collaborations (from the 1980s to the early 21st century). The term “biodiversity”, which began in biology, was initially thought to embrace every living creature (Wilson 2006), but it separated the relationship between human society and the natural environment, a dichotomy that has led to an overemphasis on the bias of “native” biodiversity research and the limitations of the research space (Wang 2022). To break this limitation, the International Congress of Ethnobiology in 1988 proposed for the first time that biological and cultural diversity are inextricably linked. And the 1992 Convention on Biological Diversity also recognized the need to respect and maintain the traditional practices of indigenous and local communities regarding the conservation and promotion of local biodiversity (UNEP 1992). As some scholars have identified biological, linguistic, and cultural diversity as being threatened by the same forces (Harmon 1996), they have proposed thinking about the integration of human culture into biodiversity. Earlier studies have used the distribution of linguistic diversity as a proxy for assessing the level of cultural diversity, confirming the positive spatial correlation between biodiversity and linguistic diversity (cultural diversity) (Harmon 1996; Loh and Harmon 2005; Stepp et al. 2004).
Since then, the concept of BCD has been defined and put into global practice (late 20th to early 21st centuries). Luisa Maffi (Maffi 2005) integrated research hotspots from multiple disciplines and summarized the concept of BCD: “Biocultural diversity comprises the diversity of life in all of its manifestations: biological, cultural, and linguistic, which are interrelated (and possibly coevolved) within a complex socio-ecological adaptive system”. The global practice has developed from three themes: exploring the correlation between biodiversity and linguistic diversity; measuring and assessing BCD; and researching the loss and sustainability of BCD (Maffi 2007). Nearly a decade later, scholars have explored how BCD research can mitigate global biological and cultural diversity loss in terms of study scales, types of research subjects, and relationships between study areas and cities. For example, some scholars have studied the remedial conservation of declining BCD at national and regional scales (Arnaiz-Schmitz et al. 2018; Vidal and Brusca 2020). The study areas are mostly selected in remote villages, mountains, sacred sites, and other edge areas with high BCD to explore the interaction between local indigenous peoples and natural ecosystems, biocultural loss factors and solutions (Agnoletti et al. 2019; Haider et al. 2020). In contrast, in crowded areas or on the edges of cities far from nature, the exploration of BCD in the context of modern civilization is still in its early stages. It is not ready to cope with single economies and culture types.
The research focus on BCD has not made a great breakthrough in three decades. We summarize that there are at least three reasons for the slow advancement of the research process: (1) The parallel problem of interdisciplinarity after the emergence of the field of BCD research. The field of biodiversity belonging to the natural sciences is centered on nature, while humans and society were initially excluded, and only later were cultural factors introduced into the field of biodiversity for correlative studies. Cultural diversity is a subfield of the social sciences that investigates the relationship between language, customs, economy, and other factors with nature. The difference in the core and the staggered research of scholars on both sides have led to a blocked integration of the two disciplines. Biodiversity and cultural diversity have thus undergone a transition from simple overlay to organic integration. (2) The disciplinary character of BCD has led to the limitation of hotspot research areas. Biodiversity research has mostly focused on pristine areas without human disturbances, while cultural diversity research has focused on indigenous cultures and endangered languages. This has led to a fixed mindset of BCD to the higher diversity of local culture and ecology, far from the central areas of political and economic activity under modern civilization. As a result, BCD has been criticized by some scholars as "primitivism" that sacrifices less diverse regions (Brosius and Hitchner 2010; Cocks 2006). (3) Finally, BCD research suffers from the problems of data acquisition, insufficient funding, and integrating the knowledge of interdisciplinary experts. On the one hand, regional BCD studies at different scales cannot be conducted without reliable biological and cultural data sets. On the other hand, research requires the integration and application of interdisciplinary expertise.
The current research on BCD is facing a dilemma from theoretical approaches to practical implementation, and there is an urgent need to protect and enhance BCD at the world level. Previous reviews of BCD have focused on the importance statement and protection recommendations of the indigenous traditional knowledge (Fernandez-Llamazares and Cabeza 2018; Fernandez-Llamazares et al. 2021; Sharifian et al. 2022; Turner et al. 2022), BCD in an urban context (Buizer et al. 2016; Vierikko et al. 2016) and its concepts and approaches (Franco 2022; Gavin et al. 2015). However, these reviews are limited to special topics, such as knowledge systems, urban green space, biocultural approaches, and so on, without providing a systematic review of existing research focus in the field of BCD. We conducted a grounded theoretical analysis of the full papers of BCD literature in recent years to break the stagnation and provide a theoretical contribution to the region-wide enhancement of BCD. The three specific objectives of this review are: 1) to construct the framework of recent research on BCD and to identify the research focus;2) to propose comprehensive pathways to enhance BCD, and 3) to summarize the gaps and guide the potential future directions of the field. The research intends to provide a theoretical contribution to future BCD implementations.