Local communities have somehow survived and have taken care of their environment since long before nature conservation and grocery stores based on intensive farming were invented, and therefore, they may know something we still need to learn. Biosemiotician Timo Maran repeatedly stresses in his recent book (2020) that current environmental issues are derived from a semiotic problem, the result of semiotic pollution, or the corrupt way we relate to the ecosystem. Maran refers to Kalevi Kull, outlining the motivation of our actions by “our sign-based distinctions” and stressing that the impoverishment of the ecosystem is the result of self-contained culture [21: 2]. Basing his argument on Juri Lotman’s communication theory and Gregory Bateson’s epistemology of the sacred, he proposes that “normal functioning of culture depends on the dialogue with what lies outside of cultural codes and hierarchies”, indicating the necessity to support interactive practices with “the rest of ecosystem” (Ibid). Maran emphasises the importance of tacit knowledge (an idea framed by Hungarian philosopher Michael Polanyi as a kind of pre-linguistic knowledge acquirable only through participation, living through the process) and its impact on our relationship with nature (Ibid: 27). Indeed, all the knowledge and skills acquired from the environment are of very participatory origin and without an actual hands-on approach the relationship cannot function. Maran refers to Sebeok stressing: “humans are semiotically rooted in nature” (Ibid: 29), yet those roots tend to fade in modern lifestyle.

In ethnobotany, the majority of scientific publications speak about explicit (languaged) knowledge: it is easy to document. Tacit knowledge cannot be easily documented [6], as it is learned only through person-to-person instruction or through personal experience/experimentation. It may not have any names or it may have them in some cultures or languages but not in others. The opportunities to express tacit knowledge through the explicit are limited, as not all experiences can be named. Culture and language are developed in a specific environment and shape the way we perceive ourselves and (in) that or any other environment.

Let’s take foraging as an example. Some aspects of the explicit form of foraging practices (like plant names and the names of the local dishes) are intensively studied and addressed in the majority of wild food plant-related research. Recently, the ethno-organoleptic properties of wild plants have also been covered [28]. At the same time, ethnoecological terminology (like names of habitats or types of landscape) is very rarely addressed [23]. Even in these limited studies, many aspects have been largely neglected (like local names of plant parts, different levels of readiness of plants for consumption, references to poisons, to name only a few). The corpora of LFK components are much more diverse (Fig. 1) and have not yet been completely mapped, even for languaged forms of LFK.

Complexity of local foraging knowledge. Designed with adobe stock

Since February 2002, when then US Secretary of State for Defence Donald Rumsfeld highlighted the “unknown unknowns” for political decisions, the concept has become viral. The existence of the unknown unknown has already been acknowledged in experimental biology [15], although in relation to ethnobiology only the level of the known unknown has been recognised, introduced by other disciplines [13]. The idea has long been used in business management and derives from the field of cognitive psychology: in 1955, two American psychologists, Joseph Luft and Harrington Ingham, developed the visual tool called the Johari Window [20]

Using the original Johari Window as a matrix, I adapt it to LEK studies in a way that opens a new perspective. However, we need to keep in mind that even if the notion of knowledge is widespread for LEK, we should not forget the initial definition of TEK: as the complex of knowledge, practices, and beliefs contained in TEK [3] does not correspond to the notion of knowledge in science. Therefore, in this context, I suggest talking about the acknowledgement of LEK elements by people and leaving the knowledge as a term when we speak about science in the context of Johari Window. Knowledge is the understanding or awareness of information, facts, or principles (e.g. scientific component), whereas acknowledging is the act of recognising or accepting the existence of specific knowledge by people. In simpler terms, what I hereafter call known refers to what science knows, while acknowledged refers to the reflection of people on their practices related to the environment. So, LEK–science interactions can be divided into four categories on a known–unknown/acknowledged–unacknowledged scale (Table 1).

Known and acknowledged is LEK which people refer to as to their own (e.g. whose existence is acknowledged) and realise its value, while it makes sense for science as well (e.g. it is scientifically comprehended and/or documented). It refers to scientifically proven (or accepted) elements of LEK that have become common knowledge and seemingly hold no potential interest in science (like long-tested or described medicinal plants or widely used wild food plants). It is kind of boring, but there are many publications that consider long-proven trajectories, which are still needed in order to see the “big picture”.

The known but unacknowledged category consists of components of LEK which are studied by scientific discourse but not considered important to people, even if those elements are part of their everyday routine. Sometimes I sense people’s genuine interest in trying to understand why such highly educated guests are interested in what they had for dinner or how they search for a plant while they are instead offering to list for us the medicinal plants they have learned from a TV show or book which they value highly at a specific moment. Those are elements of LEK that we, as scientists, study without people actually giving them value. A major part of hypothesis-driven scientific investigation covers this category. We study what we find interesting for science, even thinking sometimes that we do science for people. Our goal is to prove or deny the existence of the phenomena that we, scientists, know or think exist. We assume that LEK contains some knowledge that may be able to help to solve humanity’s challenges; we just need to understand which and how. The easiest example is related to bioprospecting: by screening for bioactive molecules in exotic medicinal plants with certain characteristics, we can evaluate the level of their efficacy even if people use them for other purposes.

The unknown but acknowledged category can also be covered by science, but more on the qualitative side. This is new knowledge for science, which is discovered when science is done with people or as a result of long-term observations and participation in community life. Rarely, the elements belonging to this category can be discovered as a side-product of hypothesis-driven research, but most often they are simply ignored or deemed unimportant (like ad hoc names, blurred elements of knowledge, new book-based uses, and many more).

The unknown and unacknowledged is the most interesting category for our discussion. Science has no idea that it exists, as it cannot yet comprehend it from a scientific point of view). People also do not acknowledge its existence (in a way that science could grasp it), although it may be an integral part of their practices and beliefs. Being unknown and unacknowledged, these elements cannot be named, for now. The moment either science or people account for any of it, such an element automatically moves into one of the other three categories.

To start talking about these unknown and unacknowledged elements, we would need to name them first. In ecology, there is a relatively recent concept of dark diversity, which encompasses the diversity that cannot be observed (e.g. missed by sampling performed in a specific place) yet affects the observable diversity and helps to understand the composition and dynamics of ecological communities [26]. The idea of dark diversity is derived, although a bit unconnectedly, from the concept of dark matter in astronomy, which corresponds to 90% of all matter in the universe and whose discovery and description caused a scientific revolution [9]. Although dark knowledge has already been defined as something hidden and forbidden [5], we could use the term dark local knowledge (DLK) to describe the unknown and unacknowledged aspects of LEK. DLK can potentially provide us with the invaluable touch of experience of countless generations, opening for us different ways of seeing reality. Dark local knowledge, thanks to the hieratic nature of LEK, may still possess yet unknown aspects supporting the sustainability of human life.

One may question that if DLK is unknown and unacknowledged, how can we find it and if we need to do it? Here, we should not forget about the practice and believes contained in the definition of LEK and should rely on the theory of partial overlap defined by David Ludwig [19], suggesting the importance of failures alongside successes in knowledge integration of Indigenous and Western scientific ontologies, as full integration often fails to accept Indigenous standpoints. In his path-breaking book Culture and Explosion [16], semiotician Juri Lotman, in the chapter on monolingual systems, describes the communication process as the exchange of information through the points of reference jointly shared by the two communicating entities. Yet, dialogue is possible only as the result of the existence of the non-intersecting parts of the knowledge systems of two communicating entities: the more diverse they are, the more productive the communication is. Without involving non-intersecting parts, the dialogue turns into a monologue, as both entities know what it is all about and when the otherness is exhausted, the exchange is no longer possible, and diversity cannot be celebrated. Exchange and tolerance of being different can produce, instead, higher diversity for both humans and the environment they inhabit; for example, multi-cultural co-existence in Iraqi Kurdistan created high diversity in gathered wild vegetables as there was space for every culture to develop along its own trajectory [27]. A richness which, even in the face of war, has survived and gives hope to people.

Local Knowledge System studies are badly needed to understand and reinforce our relationship with the environment. Because of frightening “end of the world” narratives and losing touch with ourselves and with the environment, humanity faces a “myth gap” [11]: facts and arguments are not enough, we again need stories that tell us who we are, where we live, and where we are going. LEK (and DLK) may provide the tools to help overcome this gap, supporting local communities and offering positive examples of reciprocal coexistence and restoring relationships with and within the environment. Our goal is to amplify and resonate “shared stories that become real, create context, meaning and shared purpose for framing decisions and guiding action” [1].