Nature-based social prescribing programmes: opportunities, challenges, and facilitators for implementation.

BACKGROUND: Evidence on the health benefits of spending time in nature has highlighted the importance of provision of blue and green spaces where people live. The potential for health benefits offered by nature exposure, however, extends beyond health promotion to health treatment. Social prescribing links people with health or social care needs to community-based, non-clinical health and social care interventions to improve health and wellbeing. Nature-based social prescribing (NBSP) is a variant that uses the health-promoting benefits of activities carried out in natural environments, such as gardening and walking. Much current NBSP practice has been developed in the UK, and there is increasing global interest in its implementation. This requires interventions to be adapted for different contexts, considering the needs of populations and the structure of healthcare systems. METHODS: This paper presents results from an expert group participatory workshop involving 29 practitioners, researchers, and policymakers from the UK and Germany's health and environmental sectors. Using the UK and Germany, two countries with different healthcare systems and in different developmental stages of NBSP practice, as case studies, we analysed opportunities, challenges, and facilitators for the development and implementation of NBSP. RESULTS: We identified five overarching themes for developing, implementing, and evaluating NBSP: Capacity Building; Accessibility and Acceptability; Networks and Collaborations; Standardised Implementation and Evaluation; and Sustainability. We also discuss key strengths, weaknesses, opportunities, and threats for each overarching theme to understand how they could be developed to support NBSP implementation. CONCLUSIONS: NBSP could offer significant public health benefits using available blue and green spaces. We offer guidance on how NBSP implementation, from wider policy support to the design and evaluation of individual programmes, could be adapted to different contexts. This research could help inform the development and evaluation of NBSP programmes to support planetary health from local and global scales.

The influence of urban trees and total vegetation on asthma development in children.

Objective: We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass) and season. Methods: We used a cohort of all children born in Montreal, Canada, between 2000 and 2015. Children and cases were identified from linked medico-administrative databases. Exposure to residential vegetation was estimated using the Normalized Difference Vegetation Index (NDVI) for total vegetation and using the total area covered by deciduous and evergreen crowns for trees in 250 m buffers centered on residential postal codes. Seasonal variations in vegetation were modeled by setting values to zero on days outside of pollen and leaf-on seasons. Cox models with vegetation exposures, age as a time axis, and adjusted for sex, material deprivation, and health region were used to estimate hazard ratios (HR) for asthma development. Results: We followed 352,946 children for a total of 1,732,064 person-years and identified 30,816 incident cases of asthma. While annual vegetation (total and trees) measures did not appear to be associated with asthma development, models for pollen and leaf-on seasons yielded significant nonlinear associations. The risk of developing asthma was lower in children exposed to high levels (>33,300 m2) of deciduous crown area for the leaf-on season (HR = 0.69; 95% confidence interval [CI] = 0.67, 0.72) and increased for the pollen season (HR = 1.07; 95% CI =1.02, 1.12), compared with unexposed children. Similar results were found with the Normalized Difference Vegetation Index. Conclusion: The relationship between urban vegetation and childhood asthma development is nonlinear and influenced by vegetation characteristics, from protective during the leaf-on season to harmful during the pollen season.

Strong variations in urban allergenicity riskscapes due to poor knowledge of tree pollen allergenic potential.

Exposure to allergenic tree pollen is an increasing environmental health issue in urban areas. However, reliable, well-documented, peer-reviewed data on the allergenicity of pollen from common tree species in urban environments are lacking. Using the concept of 'riskscape', we present and discuss evidence on how different tree pollen allergenicity datasets shape the risk for pollen-allergy sufferers in five cities with different urban forests and population densities: Barcelona, Montreal, New York City, Paris, and Vancouver. We also evaluate how tree diversity can modify the allergenic risk of urban forests. We show that estimates of pollen exposure risk range from 1 to 74% for trees considered to be highly allergenic in the same city. This variation results from differences in the pollen allergenicity datasets, which become more pronounced when a city's canopy is dominated by only a few species and genera. In an increasingly urbanized world, diverse urban forests offer a potentially safer strategy aimed at diluting sources of allergenic pollen until better allergenicity data is developed. Our findings highlight an urgent need for a science-based approach to guide public health and urban forest planning.

A technique for the management of posttraumatic aniridia and aphakia.

Aim: To describe our results with HumanOptics IOL-ArtificialIris complex in post traumatic aphakia and aniridia. Methods: Retrospective, single-surgeon chart review of cases in which aniridia and aphakia were corrected using HumanOptics IOL-ArtificialIris complex sutured to the sclera with Gore-Tex® sutures and coupled with the Akreos® IOL (Bausch&Lomb). Results: The authors present four cases of ocular trauma with globe rupture. For every patient, posterior vitrectomy was done and an artificial iris-lens diaphragm was sutured to the sclera. All patients had a good functional and cosmetic outcome. Conclusions: Surgical implantation of the HumanOptics IOL-ArtificialIris complex coupled with the Akreos® IOL was successful in alleviating post-trauma aphakia and aniridia related visual impairment.

Distinct growth responses to drought for oak and beech in temperate mixed forests.

PURPOSE: Droughts are expected to become more intense and frequent. Mixed forests can be more resilient to extreme events, but are the individual trees in mixed forests also more resilient to drought? METHODS: We sampled 275 trees in 53 temperate forest stands in northern Belgium: monocultures, two-species mixtures, and the three-species mixture of Fagus sylvatica, Quercus robur, and Q. rubra. We related the annual basal area increment of individual trees to drought severity from 1955 to 2015 and calculated growth resistance, recovery, and resilience for six contrasting drought episodes (spring, summer, or full-year drought). RESULTS: Tree growth of the diffuse-porous F. sylvatica was more sensitive to drought, summer drought in particular. The ring-porous Q. robur and Q. rubra were mainly affected by spring drought. In general, a tree's growth response to drought was not affected by tree species diversity, but some identity effects emerged. CONCLUSION: The asynchrony in drought responses among the tree species (a large and immediate decrease in growth followed by swift recovery in F. sylvatica vs a smaller delayed response in Quercus) might stabilize productivity in forests in which both are present. The impact of the predicted increasing drought frequency will depend on the timing of the droughts (spring vs summer).

Tree diversity mitigates defoliation after a drought-induced tipping point.

Understanding the processes that underlie drought-related tree vitality loss is essential for anticipating future forest dynamics, and for developing management plans aiming at increasing the resilience of forests to climate change. Forest vitality has been continuously monitored in Europe since the acid rain alert in the 1980s, and the intensive monitoring plots of ICP Forests offer the opportunity to investigate the effects of air pollution and climate change on forest condition. By making use of over 100 long-term monitoring plots, where crown defoliation has been assessed extensively since 1990, we discovered a progressive shift from a negative to a positive effect of species richness on forest health. The observed tipping point in the balance of net interactions, from competition to facilitation, has never been reported from real ecosystems outside experimental conditions; and the strong temporal consistency of our observations with increasing drought stress emphasizes its climate change relevance. Furthermore, we show that higher species diversity has reduced the severity of defoliation in the long term. Our results confirm the greater resilience of diverse forests to future climate change-induced stress. More generally, they add to an accumulating body of evidence on the large potential of tree species mixtures to face manifold disturbances in a changing world.