Mindfulness, historically rooted in Eastern spiritual practices, has evolved significantly within secular Western contexts since the 1970s, largely due to the efforts of Jon Kabat-Zinn (Noonan,
2014; Raj & Kumar,
2019). Initially embracing a spiritual and theoretical approach, mindfulness has shifted towards a more pragmatic application in contemporary settings (Lee et al.,
2021). Although today’s Western conceptualization of mindfulness incorporates central Buddhist principles and preserves foundational tenets such as wakefulness of mind and the development of insight (Nnanavamsa & Kirshnasamy,
2014; Rhys Davids & Stede,
1959), it is also recognized as a distinct, emerging cultural phenomenon (Schmidt,
2011). Thus, this modern adaptation draws from Eastern philosophy but diverges in certain respects from traditional Buddhist practices (Lee et al.,
2021; Schmidt,
2011). Today, mindfulness is well-defined as “the awareness that emerges through paying attention on purpose, in the present moment, and nonjudgmentally to the unfolding of experience moment by moment” (Kabat-Zinn,
2003, p. 145).
Nisbet et al. (
2009) viewed this person–nature relationship as an experience of connectedness to nature (CN), which can be described as “the affective, cognitive, and experiential relationship individuals have with the natural world or a subjective sense of connectedness with nature” (p. 719). This connection to nature has been associated with the capacity to develop a deepened sense of wellbeing (Howell & Passmore,
2013; Lumber et al.,
2017), and is considered to be psychologically restorative (Bragg & Atkins,
2016; Scopelliti et al.,
2019). Two theories that address the psychologically restorative properties of nature include attention restoration theory (ART; Kaplan & Kaplan,
1989) and stress reduction theory (SRT; Ulrich,
1983), which are both rooted in the biophilia hypothesis. The term biophilia was first used by Fromm (
1992) to describe “the passionate love of life and of all that is alive.” (p. 406). This was further developed by Wilson (
1984) to include having an inherent affiliation for natural forms of life. Since then, it has been conceptualized as an innate tendency to positively respond to nature, which stems from the need to adapt to an evolving environment (Scopelliti et al.,
2019).
To address the lack of integrative knowledge, the overarching aim of the scoping review study was to develop a better understanding of the diversity of contemporary NBM interventions. In order to achieve this overarching aim, the following research questions were formulated to guide the study: (1) What practices and methods are used in NBM interventions, and (2) environmental conditions are typically associated with NBM interventions?
Discussion
Research Question 1, which was aimed at identifying what practices and methods are used in NBM interventions, resulted in the generation of four themes: (1) conventional mindfulness practices combined with nature, (2) activity-based practices using nature, (3) NBM therapy practices, and (4) emerging practices. When looking at these categorizations it is clear that NBM interventions exhibit significant diversity and lend themselves to a wide range of therapeutic contexts.
HReST or MBSR-based NBM practices are for instance both conventional practices that are used for the treatment of stress-related difficulties (ReST; Lymeus et al.,
2019) or to improve general wellbeing (MBSR; Choe et al.,
2020a). NBM interventions such as Shunda or forest therapies are both activity-based practices that have been effectively used for either the treatment of substance-use disorders (
Shunda; Russell et al.,
2016) or depressive symptoms (forest therapies; Lee et al.,
2017). Other examples include using NBT, an NBM therapy practice aimed at improving symptoms of binge eating disorders (Corazon et al.,
2018a,
2018b); guided imagery, which falls under emerging practices, to improve anxiety symptoms (Nguyen & Brymer,
2018); and MBSR, adapted to a VR context, also an emerging practice, aimed at improving mental health and wellbeing (Choe et al.,
2020b). These are only a few examples of different NBM interventions that apply a variety of methods and practices in different clinical and nonclinical settings. Based on the above, it becomes clear that the diverse methods of facilitating mindfulness and incorporating nature in the different NBM interventions create a flexible and inclusive approach that is suitable for application in a vast range of clinical and nonclinical contexts.
Considering this diversity of practices and methods in multiple contexts,
population group suitability is an important factor to consider when determining the potential effectiveness of NBM interventions and their associated practices and methods. This factor was considered in several reviewed studies (see Høegmark et al.,
2021; Maund et al.,
2019; Russell et al.,
2016). For example, MBEs, according to Russell et al. (
2016), are regarded as suitable and effective NBM intervention approaches for young adult males suffering from substance-use disorders. Similarly, Høegmark et al. (
2021) reported that the predominant use of NBAs to facilitate mindfulness, which is considered a non-traditional therapeutic approach, was particularly effective and suitable for male populations who are more likely to resist traditional pathology-based or treatment-based approaches. One possible reason for this finding is that “nature can be experienced by the participants as a neutral place where they are not constantly reminded that they are engaged in a health course, and they are to a lesser extent reminded that they are sick” (Høegmark et al.,
2021, p. 15).
While the review did not explicitly focus on the population group suitability, findings did suggest the possible significance of this factor. Consequently, when considering the use of NBM interventions and the specific methods and practices employed, effectiveness should ideally be evaluated in a population-specific context rather than in a general manner. As such, the question is not so much which practices and methods should be used?, but rather which practices and methods should be used for this specific population?.
The review of practices and methods used in NBM interventions identified multiple forms of nature-based engagement aimed at facilitating mindfulness, including direct, indirect, passive, and active forms of engagement. For example, canoeing is a form of direct and active engagement with nature (Russell et al.,
2016), whereas mindful movement in nature is considered indirect and more passive (Choe et al.,
2020a; Clarke et al.,
2021). During the course of the review, there were no indications that some forms of engagement were necessarily more effective than others in terms of facilitating mindfulness. Instead, the findings indicate that all forms of nature-based engagement (direct, indirect, passive, and active) are potentially suitable to facilitate mindfulness (see Burgon,
2013; Choe et al.,
2020a; Clarke et al.,
2021; Johnson et al.,
2020; Lymeus et al.,
2019; Russell et al.,
2016). Literature supports this conclusion, stating that all forms of nature-based engagement have the capacity to develop a multidirectional relationship between nature and the individual (Meuwese et al.,
2021; Stigsdotter et al.,
2011), which is important for the facilitation of mindfulness. Therefore, it may be that engagement with nature in any of a variety of different ways positively impacts mindfulness to some degree. This lack of differentiation between specific forms of nature engagement in terms of its effectiveness in facilitating mindfulness, could however be due to the lack of comparative studies on the topic. The effectiveness of using different forms of nature-based engagement to facilitate mindfulness fell outside of the scope of this research, but represents a potentially fruitful avenue for future research.
The second research question, which was aimed at identifying what environmental conditions are typical of NBM interventions, prompted the identification of the following three themes: (1) naturally occurring environments, (2) curated natural environments, and (3) simulated natural environments.
From these themes, it is again clear that a wide range of environmental conditions have the capacity to facilitate mindfulness. Despite differences in the characteristics of the nature-based contexts used, all were reported to have restorative potential and to facilitate a state of mindfulness. For instance, environments characterized as biodiverse, sensory-rich, and secluded, such as wetlands and forests, were reported to offer restorative characteristics that adequately facilitate mindfulness (Clarke et al.,
2021; Maund et al.,
2019). Similarly, environments that are regarded as less biodiverse and more populated, such as parklands, are likewise capable of facilitating mindfulness (Choe et al.,
2020a), as are the virtual environments that were employed in some of the emerging NBM interventions (Choe et al.,
2020b).
Findings from existing literature did, however, suggest that individual preference, possibly mediated by one’s mental state, may play a role in how effective different environmental conditions are in eliciting mindfulness (Corazon et al.,
2010; Poulsen et al.,
2016,
2018). This contention is supported by Poulsen et al. (
2016), who found that an individual is likely to “seek a connection between the characteristics of the natural setting in the location of their choice and their mental state” (p. 6). This perceived match between the environment and mental state is a subjective experience that may also change as the intervention progresses, since
mental state is considered dynamic and subject to change (Poulsen et al.,
2016).
As such, even though all environmental conditions included in the review are reported to have restorative potential and the capacity to facilitate mindfulness, individuals may prefer environments that match their mental state. This matching is necessary to achieve an optimal restorative state, and is referred to as
compatibility (Kaplan,
1995), which is defined as “a good fit between a person’s inclinations or goals and what the setting facilitates or encourages” (Herzog et al.,
2011b, p. 91). This compatibility between the environment and the individual’s inclination and motivation (and therefore the need at that specific time), increases the perceived support the environment offers (Berto,
2014; Herzog et al.,
2011a). Since it is reasonable to assume that most individuals would prefer an environment that is perceived as supportive, compatibility may be a vital consideration when deciding on a particular nature-based context for the facilitation of mindfulness. The potential significance of this in the context of NBM interventions is not a well-researched area. As such, it may be of benefit to better understand whether individuals with certain mental states (i.e., depressive or anxious inclinations) perceive certain environmental conditions as more compatible, and therefore, more supportive. This improved understanding could better inform the choice of environmental conditions, and their associated characteristics, to optimally facilitate mindfulness in NBM interventions.
In this review, forest/woodland environments were the most commonly used to facilitate mindfulness. These immersive and sensory-rich environments are highly restorative and are considered natural healers (Abdullah et al.,
2021; Clarke et al.,
2021; Poulsen et al.,
2016). They embody Kaplan’s (
1995) restorative characteristics, offering a sense of being away, fascination, extent, and compatibility. However, the review shows that other environments that may offer similar characteristics and benefits have been largely underrepresented. This is supported by Maund et al. (
2019), who point out that wetlands, characterized as biodiverse and sensory-rich, “represent a valuable ecosystem for the promotion of mental health that, to date, has been largely overlooked” (p. 11). To address this neglect, future research could consider exploring the mindfulness-inducing properties and benefits of a diverse range of new and previously overlooked environments, such as alternative nature conservation areas (e.g., bushveld, floral kingdoms, or marine protected areas) that possibly offer similar outcomes in the facilitation of mindfulness. As a benefit of doing so, this field may find greater diversity in NBM contextual applications and improved accessibility due to the greater variety of applicable environmental contexts.
As part of the theme representing simulated environments, nature-based VR simulations emerged as the predominant area of focus (Abdullah et al.,
2021; Choe et al.,
2020b; Rozmi et al.,
2020). More specifically, research has focused on using VR as a potentially innovative solution that addresses, at least in part, issues of accessibility due to increasing rates of urbanization (Abdullah et al.,
2021; Rozmi et al.,
2020). While not a prominent finding in this review, nature-based guided imagery (GI) also emerged as a method used to simulate natural environments that address the effects of urbanization (Nguyen & Brymer,
2018). In the past, these approaches have been criticized for lacking professional training and for the lack of proper implementation (Sierpina et al.,
2007). However, since then new avenues and possibilities for training opportunities have been subjected to scholarly research (Rao & Kemper,
2017), and has contributed to its scientific rigor. Current literature indicates that mindfulness-based guided imagery practices are effective and feasible cost-effective approaches (Bigham et al.,
2014; Carroll,
2022).
Despite these favourable views, guided imagery as an NBM intervention seems underutilized, and consequently under-researched, based on the fact that this review only identified one article using nature-based GI (see Nguyen & Brymer,
2018). Given that even simulated environments are regarded as highly restorative and as having the capacity to improve mindfulness (Choe et al.,
2021), future studies could focus on developing nature-based GI as an NBM intervention. Nature-based GI may represent a cost-effective means of facilitating mindfulness in the absence of actual natural spaces, while still capitalizing on nature’s restorative benefits. Given that simulated environmental conditions are not bound to the constraints of the physical world, future research could explore novel environments that would be inaccessible in the context of regular NBM interventions. For example, underwater VR environments or aerial VR environments could offer a wider variety of newly accessible environmental conditions and novel avenues for the facilitation of mindfulness that are not restricted by the structures of existing NBM interventions or the physical environments that individuals have access to.
Limitations and Future Research
This review was not without limitations. Firstly, the inclusion criteria were limited to English language peer-reviewed studies. The studies included therefore generally represent perspectives and practices of dominant Western cultures, and possibly do not adequately address, for instance, African or Eastern perspectives. The findings may therefore also be limited in terms of their generalizability. Within these constraints, and in line with the rationale for doing a scoping review, the authors did endeavour to be as inclusive as possible in terms of the themes and subthemes identified in the existing literature. Topics like horticultural practices and animal-assisted practices (interventions within activity-based practices), GI (an intervention within emerging practices), and NBR (an intervention within NBM therapy practices) were therefore included, although they were represented by only a small number of studies. The relative scarcity of information on these aspects could possibly be ascribed to the small number of studies specifically related to these practices, or to the fact that existing studies contain only a tenuous or absent link to mindfulness. Both of these potential limitations offer lacunae that could be addressed in future research.
Overall, this scoping review aimed to provide an integrative understanding of existing NBM interventions by addressing the following two research objectives: (1) to describe what practices and methods typically form part of NBM interventions, and (2) to determine the environmental conditions that are typically associated with NBM interventions. From the included studies (
n = 30), a typological scheme for categorizing NBMS was proposed (Fig.
2) in which four main categorizations of NBM interventions were identified, including (1) conventional practices combined with nature, (2) activity-based practices using nature, (3) NBM therapy practices, and (4) emerging practices.
It was found that NBM interventions offer a diversity of non-traditional approaches that are suitable in various clinical and nonclinical contexts. Compared to pathology or treatment-based approaches, these interventions appear to be met with less client resistance. Furthermore, the review suggested areas of research that would enhance evidence-based practice by addressing ways to improve the suitability and effectiveness of various types of NBM interventions. As such, it is proposed that research focuses on population group suitability and individual compatibility with certain types of nature engagement.
In relation to the second research objective, three environmental conditions emerged that characterize the natural contexts within which existing NBM interventions typically take place, including (1) naturally occurring environments, (2) curated natural environments, and (3) simulated natural environments. It was found that all environmental conditions and their associated characteristics offered restorative conditions that effectively contribute to the facilitation of mindfulness. However, focused research is needed to determine whether certain environmental characteristics are perceived as more or less supportive for certain mental states, and to integrate previously overlooked environments to expand on existing NBM interventions and facilitate improved accessibility. Simulated natural environments offer potential alternatives in this regard, which include the development of cost-effective environmental simulations (nature-based GI) and the exploration of novel environments that are not bound to constraints associated with having physical access to natural spaces.
Overall, this review offers a more integrated understanding of the different practices and environments currently used within the existing field of NBM intervention. This could serve as a basis upon which future research can build to address the gaps noted in the discussion, and thereby enhance evidence-based practice.