Nature-based early learning and childcare - influence on children's health, wellbeing and development: literature review

Discussion

This systematic review aimed to synthesise existing global literature to examine whether attending nature-based ELC influenced children's physical, cognitive, and social and emotional development. This was a comprehensive review of a large body of both quantitative and qualitative evidence.

Key findings

Findings from the quantitative evidence suggested predominately positive associations across a number of outcome domains and sub-domains. These are summarised below.

Based on very low and moderate evidence, playgrounds which included grassed areas, vegetation, natural elements, rocks, hills or shaded areas were positively associated with increased total physical activity, moderate-to-vigorous physical activity (MVPA) and step counts and decreased sedentary time during ELC.

Based on low and moderate evidence, compared to traditional ELC, nature-based ELC was positively associated with:

• balance
• self-regulation (ability to understand and manage behaviour)
• nature relatedness (or biophilia)
• play interactions

Based on moderate evidence, compared to traditional ELC, nature-based ELC was negatively associated with children's speed and agility.

Based on very low, low and moderate evidence, compared to traditional ELC, nature-based ELC had inconsistent findings on the following outcomes:

• object control skills
• attention
• social skills
• social and emotional development
• attachment
• initiative
• awareness of nature
• environmentally responsible behaviour
• illnesses
• behavioural problems (such as temper tantrums or hyperactivity)
• play disruption (aggressive and antisocial behaviours in play) and disconnection (withdrawn behaviour and nonparticipation in play)

Findings from the qualitative (e.g. practitioner reported feedback) element of the review also generally reported positive findings:

• Nature affords many more opportunities for children to be active, diversify their play, engage in risky play, interact with peers and teachers, increase their creativity and enable child-initiated learning compared to traditional settings.
• Nature-based ELC affords opportunities for children to be physical activity, to engage in diverse types of play and interact with peers. This combination is likely to have an impact on a range of physical, cognitive, and social and emotional outcomes (logic model).
• Children prefer settings which integrate some nature either a full naturalised playground or a mixed area. A small number of studies indicated that movement and risky play were similar no matter the setting type.

Strengths and limitations of the review process & evidence

This was a comprehensive review of global quantitative and qualitative evidence on the impact nature-based ELC on children's health, wellbeing and development. The review was guided by a steering group which consisted of experts in this area from research, policy and practice. These experts were involved throughout the project to ensure relevancy across disciplines. The review also involved international co-authors who supported data screening, translation of papers and providing important country specific contexts to ensure all global evidence was captured. A total of nine databases were searched and not restricted by publication year or language. Searches extended to websites and non-published research, and experts from policy, practice and research were contacted to provide evidence. We included all study designs and not just the "gold standard" to ensure this review provided an overview of the best available evidence to date. The review was registered to PROSPERO, an online systematic review registry, and a protocol published to BMC Systematic Reviews (22). Strict systematic review procedures were followed ensuring rigour at each step. Full text articles were screen and study quality were assessed independently by two reviewers.

However, we were unable to screen titles and abstracts or extract data in duplicate. This was mitigated by screening 10% of the titles and abstracts, and data were checked by a second reviewer. The EPHPP tool used to assess quality was modified slightly to ensure relevancy for the present review, but this may have reduced the validity and reliability of the tool. Strength and limitations of the evidence - 59 unique studies (representing 65 articles) were included in this review, of which, nine were controlled before and after designs. Eligible studies were conducted across 15 countries ensuring global relevancy of the report. Studies also tended to use reliable and valid methods for assessing the outcomes which gives greater confidence in the findings presented. However, the majority of these studies were cross-sectional or controlled cross-sectional with small sample sizes meaning that we cannot be certain that any results found were because of the exposure. Studies were predominately rated weak because the children and ELC settings were unlikely to be representative, it was unclear whether the researchers or outcome assessors were aware of the research questions (potentially introducing bias into the study) and withdrawals and dropouts were not reported or was high.

Implications for future research

To enhance the evidence base, future research should focus on well-designed controlled studies with larger sample sizes and robust valid and reliable measures for assessing a range of physical, cognitive, social, emotional, and environmental outcomes. This would help to understand whether benefits and possible harms are a result of attending nature-based ELC and not any other factor.

The studies included in the review only explored the short-term impacts of attending nature-based ELC (see logic model) meaning that we were unable to draw specific conclusions about possible longer-term benefits. However, we know from other literature how pathways may be drawn between the short and intermediate-term outcomes. For example (see Figure 17), previous systematic reviews have suggested that gross motor competence (movements which require the whole body such as running or jumping) is positively associated with physical activity levels in childhood and adolescence (94, 95). This relationship is bi-directional as physical activity is also associated with better motor competence (14). Young children who engage in higher levels of physical activity, particularly MVPA, are more likely to have a healthy weight (14); and obesity is both a cause and consequence of low levels of MVPA (96). Finally, evidence is suggestive of MVPA being positively associated with academic attainment (97) and higher levels of obesity being associated with lower attainment (98). This is just one example, but similar pathways exist for other short and intermediate-term goals.

Longitudinal studies that explore the impact of attending nature-based ELC over a longer period, e.g. into primary school, would a) enable us to understand the longer-term impacts and b) support continuity of policy in primary school education to ensure children continue to receive outdoor natural experiences. This is important because in Scotland the majority of children who attend nature-based ELC settings will transition into a traditional primary school setting that may offer predominately indoor and more sedentary education. This may result in children who attended nature-based ELC finding the transition more difficult, with any possible improvements gained from the nature-based experiences potentially diminishing over time.

Finally, the evidence base in the UK is limited. Only three studies were included in this review, of which, only one collected data in Scotland. As nature-based ELC increases in Scotland, it is important that more robust evidence (as described above) is collected to understand the impacts on children's health, wellbeing and development. Although evidence from other counties can be informative, each country has different policy, environmental and cultural contexts which may not translate. Examples include the weather, funding structure and country specific cultures (for example, aversion to being outdoors in poor weather or pervasive use of screen time). Most of the studies included in the review were conducted in the US or Australia where the climate is not comparable to Scotland. Similarly, many were also conducted in Norway which has a strong cultural emphasis on being outdoors in nature – the term "Friluftsliv" (translated "free air life") relates to the strong connection Norwegians have to nature (99). Finally, understanding the specific funding structure in Scotland is also an important factor. Many nature-based ELCs are still private meaning there is not equitable access for all children, although nature-based approaches are increasing through satellite and indoor/outdoor approaches in local authority ELCs.

Summary – Identified research gaps:

1. The evidence base is compounded by studies which have small sample sizes, are not controlled and use weak study designs (cross-sectional). This limits the conclusions we can draw from the evidence. Future research should be higher quality with stronger controlled designs and larger sample sizes to enable us to draw stronger conclusions on the impact of nature-based ELC on children's health, wellbeing and development.

2. None of the studies included assessed the longer-term impact of nature-based ELC on children's physical, cognitive, social, emotional and environmental development. By conducting longitudinal research, we will be able to understand more about the possible impacts of nature-based ELC and the mechanisms by which improvements occur.

3. The evidence base in Scotland and the UK is limited – only one study in the review was conducted in Scotland. Given the current focus on expanding nature-based ELC provision, it is important that more high quality research is conducted in Scotland to understand specific contexts (policy, environment and culture) and benefits (or harms) to children.

Implication for policy and practice

Based on very low to moderate quality evidence (with low number of children and studies across different outcomes), findings are supportive of nature-based approaches in ELC settings, with no findings suggesting harms to children. Across most outcomes, the findings generally favour nature compared to the comparison (traditional ELC). Only one outcome, speed and agility, was negatively associated, and this was across a small number of studies. Balance, self-regulation, nature relatedness and play interactions were positively associated with nature-based ELC compared to traditional ELC.

In Scotland there are three delivery models: outdoor (or nature-based ELC); indoor/outdoor (children move freely from indoors to outdoors); and satellite (taken to another setting for nature-based experiences). Table 11 presents the type of ELC provided per study for each outcome category where there were positive associations. The majority of studies used an outdoor approach, five studies used a satellite approach and one indoor/outdoor. It is important to highlight that irrespective of approach, in studies with favourable outcomes, children were exposed to large amounts of nature on almost a daily basis. For example, for studies that used a satellite approach, children had daily trips (18, 43, 59, 60, 79) meaning children spent most of their time outdoors in nature. Similarly in the study with the indoor/outdoor approach (35), children were allowed outdoors when they wanted but also participated in a weekly forest programme. It is important to highlight that these studies were conducted in countries which may have a better climate than Scotland meaning that it is perceived to be easier to be outdoors daily. However, across indoor/outdoor and satellite settings in Scotland, with support from the practitioners, it might be useful to quantify how regularly children are outdoors in nature to understand whether this can be improved. Findings from this report are important in providing evidence for expansion of free ELC entitlement; however, if nature-based approaches continue to increase in Scotland, these should be supported by robust research (as detailed in the previous section) to understand more about the impacts and any possible causal pathways.

Table 11. Positive outcomes grouped by type of nature-based ELC provision.

Outcome	Study	Description of nature-based ELC	Scottish ELC category	Discussions and implications
Balance	Ene-Voiculescu & Ene-Voiculescu (2015), Norway (18, 59, 60)	Children used the forest next to the ELCs every day for 1-2 hours throughout the year when they attended kindergarten. The small forest (7.7 hectares) consisted of mixed woodland vegetation, some open spaces of rocks and open fields and meadows in between. Occasionally they used the outdoor playground inside the ELCs.	Satellite	Nature-based ELC was significantly positively associated with balance in two out of three studies. All three studies used highly naturalised settings which are likely to afford opportunities for children to develop their balance (rocks, logs etc). It was unclear why the third study (Lysklett) was not positively associated with balance given the exposure was similar across these studies.
	Scholz & Krombholz (2007), Germany (62)	Forest kindergarten.	Outdoor
	Lysklett et al (2019), Norway(61)	Nature-based ELCs located close to a large recreational area, with woods, lakes and tracks just outside the city centre. They used the nearby nature area for hiking and playing least three times, per week	Satellite
Self-regulation	Cooper (2018), England (35)	Forest school sessions run by two trained leaders which operate for 10 week cycles on Tuesday AM and PM (2 hours each). Children attend either the AM or PM session. The forest school consists of trees and vegetation, a seating area made from logs, a mud kitchen using old crates and a tyre, a greenhouse and pond. The forest school is located on site and when children do not have forest school sessions outdoors, they have a " free flow" environment where children are allowed outside when they want.	Indoor/ outdoor	Nature-based ELC was positively associated with self-regulation in three studies (significant in two). All three studies had a high exposure to nature where children spend the majority of their time outdoors.
	Ernst et al (2019), USA (68, 70)	The ELCs utilised a combination of wild natural settings spaces that were minimally managed and natural playscapes designed specifically for nature play. The majority of time spent was in free play outdoors in unmaintained or minimally maintained natural settings regardless of weather conditions (approximately four to five hours per day). Children at both groups had one to two hours of daily outdoor playtime (weather permitting) in a maintained outdoor space that contained playground equipment.	Outdoor
	Müller et al (2017), Canada (45)	Nature kindergarten.	Outdoor
Nature relatedness	Müller et al (2017), Canada (45)	Nature kindergarten.	Outdoor	Nature-based ELC was positively associated with nature relatedness in three studies (significant in four). These studies used a combination of outdoor and satellite sessions, indicating that any increased exposure to nature may improve nature relatedness. One study (Rice & Torquati) found neither favourable nor unfavourable associations.
	Elliot et al (2014), Canada (43)	A two-year pilot project in which 22 students would spend the mornings from 9:00 to 11:45 outside their school, exploring their local natural environment.	Satellite
	Yilmaz et al (2020), Turkey (77)	Children visited a natural, unstructured area for one day in a week for four consecutive weeks. The education programme consisted of 12 semi-structured activities (3 per week). In addition, children also had 30 minutes' walk near a natural pond when they visit the setting each week and each week, children had 30 minutes unstructured free play time to discover the natural environment.	Satellite
	Barrable et al (2020), UK (England, Scotland, Wales)(78)	ELCs that have a continuous outdoor provision, with no permanent indoor access and children are outdoors for the whole duration of the ELC day.	Outdoor
	Giusti et al (2014), Sweden (79)	ELCs were assessed on their frequency of natural experiences. Each ELCs was ranked according to the highest frequency of use of the greatest variety of nature experiences in its surroundings. This included ten ELC's with the most frequent use of all nature experiences.	Satellite
	Rice & Torquati (2013), USA (80)	The nature ELCs featured: vegetation, gardens, areas for digging in soil, sand, and "loose parts" (sticks, seeds, pinecones etc) and other naturally occurring objects that children used in their play. Climbing structures and pretend play structures such as a boat or a playhouse were also included.	Outdoor
Play interactions	Burgess & Ernst (2020), USA (67, 68)	See Ernst et al (2019)	Outdoor	Nature-based ELC was significantly positively associated with play interaction in two studies. These settings are highly naturalised where children spend most of their time outdoors. One study found a negative association (Cordiano); however, in this study children also spend most of their time outdoors in nature.,
	Robertson et al (2020), Australia (81)	ELC located in a rural area and consisted of a small traditional playground area (sand pit, obstacle course etc.) and a larger open ended nature area consisting of trees, shrubbery, grass, natural loose-parts). It has a highly naturalised area towards the rear that was rich in natural elements including small and large shrubbery, and larger tree and vegetation	Outdoor
	Cordiano et al (2019), USA (34)	Outdoor ELC programme involved children spending five mornings per week at the school's outdoor campus. The children were outdoors in the forest for 90% of the school day.	Outdoor

There are key environmental features that appear particularly important for increasing total PA and MVPA, reducing sedentary time, supporting risky play and diversifying play types, enabling different human interactions and supporting creativity. These tend to be a combination of grassed areas, vegetation, natural elements, grass, rocks, hills and shaded areas. It is important, where possible, that ELC settings afford these natural features, possibly with a combination of traditional elements (such as open space) which may enhance other outcomes. Furthermore, some qualitative evidence highlighted that children may prefer playgrounds with a mixture of nature and traditional spaces. This evidence builds on the Scottish Government's "Out to Play - creating outdoor play experiences for children: practical guidance" (20) and could support a future revised version of this document.

The majority of studies included in the review did not look at the role of the practitioner specifically. However, the evidence suggests that nature is likely to afford opportunities for children to interact differently with their peers and practitioners. Practitioners are likely to influence the experiences children have in nature-based ELC by ensuring that children have opportunity to be outdoors in nature to enable them to play, be physically active and interact with each other. It is important that practitioners understand the importance of promoting being outdoors in nature and related benefits possibly through targeting training and removing barriers.

Suggested recommendations

1. Ensure that ELCs have a rich and varied environment that includes a combination of grassed areas, vegetation, natural elements, rocks, hills and/ or shaded areas. These appear particularly important for encouraging physical activity, diversifying play types and enabling human interactions which are important for childhood development.

2. Ensure that all children can access nature across all setting types: outdoor; indoor/outdoor; satellite. In studies where there was a likely association, evidence from this review suggested that both indoor/outdoor and satellite approaches provided children with high exposure to nature. Therefore, it is important to understand how much and how regularly (daily, weekly, etc) children are exposed to/engage with nature across each setting.

3. To aide future policy development in Scotland, it is important that researchers work collaboratively with practitioners and policy makers to establish what child and ELC level outcomes should be measured and how we can best collect data on these. By embedding robust evaluation practices, we can generate stronger evidence on the impact of nature-based ELC in Scotland.