Urban and peri-urban trees, parks, forests and wetlands form what is known as the natural infrastructure (NI) providing multiple ecosystem services to surrounding populations. NI contribute to climate adaptation by storing carbon and reducing the impacts of heat waves and floods. They maintain biodiversity, mitigate air pollution, and improve water and soil quality. NI also enhance the quality of life of citizen by providing opportunities for recreation, hence promoting physical activity and reducing mental illness.Today, global changes are increasing both the vulnerability of NI and the importance of the ecosystem services they deliver to urban and peri-urban communities. By 2050, two-third of the wold population is expected to live in urban areas, intensifying the number of individuals and communities that draw or could draw direct and indirect benefits from NI. At the same time, continuous pressure from urbanization is resulting, in many cities, in the degradation of NI into small and isolated fragments with reduced biodiversity. These transformations are compromising the equitable distribution of ecosystem services and reducing the ability of NI to withstand further disturbances from climate extremes, invasive species and disease, or urban development.It is therefore crucial that land management decisions taken today insure the resilience of NI to future changes.As such, there is a pressing need to better assess and quantify the ecosystem services delivered by NI, to determine the risks posed to these benefits by potential future threats to NI, and to develop new approaches and tools that will help deciders invest in sound protection and restoration efforts of NI. This exchange session will highlight conceptual, methodological and technological advances for building resilient NI that sustain the continuous delivery of benefits to urban and peri-urban communities in the face of global changes.

This session will bring together four experts who focus on different dimensions of the topic, namely, urban forestry, public and environmental health, ecological economics and environmental governance, as well as biodiversity science and ecological connectivity, to present exciting ongoing approaches, remaining knowledge gaps and promising directions for future research. Presentations by speakers will be followed by exchanges with the participants.

1. Strategies to Promote the Implementation of Natural Infrastructures in Urban Areas

Jérome Dupras
Département des sciences naturelles, Université du Québec en Outaouais
Canada Research Chair in Ecological Economics

Through ecosystem service modeling, the analysis of semi-structured interviews held with key actors involved in the planning of the Quebec City and Montreal regions and documentary analysis, we seek to understand the conditions that could lead to the establishment of a multiscale green infrastructure for the city. This conference first describes the regions’ environmental and political context and the management and planning processes that have led to important deterioration of natural assets over the past decades. We then review the ongoing or planned programs, tools and actions that have been undertaken in the region to favour the implementation of green infrastructures, such as payment programs for ecosystem services, agro-environmental practices and new approaches in conservation policies. Finally, we analyze the opportunities, constraints, advantages and disadvantages in the implementation of this type of project in this region based on our expert survey.

2. Designing networks of natural infrastructure for socio-ecological resilience and biodiversity.

Andrew Gonzalez
Department of Biology, McGill University
Liber Ero Chair in Biodiversity Conservation
Director of the Quebec Centre for Biodiversity Science
Co-chair of the Group on Earth Observations – Biodiversity Observation Network (GEO BON)

Natural infrastructure (NI) is an important asset for cities as they adapt to the impacts of climate change. NI supplies benefits to people in the form of ecosystem services. The current management challenge lies in designing networks of NI that maintain the benefits to people throughout a city while minimizing the risks to NI from development and climate change. We have developed methods to identify and prioritize networks of NI to maintain biodiversity and ecosystem services in urban areas. I will present the results of our approach applied to Montreal. Setting priorities for the management and design of NI networks based on connectivity is an efficient strategy for ensuring the benefits to people and nature in the long term. I will describe recent initiatives applying our methodology within the city. Our approach is general and can be applied to any city in the world where NI is a priority for climate adaptation.

3. Using a functional approach to design resilient urban and peri-urban forests

Christian Messier
Département des sciences biologiques, Université du Québec à Montréal/ Département des sciences naturelles, Université du Québec en Outaouais

Hydro-Québec Industrial Research Chair on Control of Tree Growth
Canada Research Chair in Forest Resilience to Global Changes

Urban and peri-urban forests provides important ecosystem services, such as reduced environmental exposures and improved human health. These services will become even more important with climate change, especially with most humans now living in cities. Yet urban and peri-urban trees are also being threatened by changing climate, urban growth and new exotic pests and diseases. Hence, to maintain these important ecosystem services provided by urban trees and forests, it is important to develop novel management practices that are aimed at increasing their resilience. Traditional management practices have favored low-diversity tree communities for esthetic reasons or convenience. However, such low diverse communities are inherently more susceptible to collapse, as individuals will respond similarly to a given environmental stress. I will present a new management approach aimed at augmenting true diversification – favoring functional diversity and, therefore, resilience – to reduce risks and increase the potential for sustained delivery of services, to maintain or ideally increase urban tree cover.

4. The urban forest and respiratory health

AudreySmargiassi
École de santé publique - Département de santé environnementale et santé au travail, Université de Montréal
Researcher at Quebec Institute of Public Health & at the Public Health Research Center of the University of Montreal

The urban forest, which includes trees in streets and parks, is associated with health benefits due to the reduction of noise, air pollution and heat islands; as well as favoring well-being, social interactions and physical activity. Yet it is unclear what features of trees and the urban forest promote these benefits. On the contrary, tree pollen can increase allergies. As part of this presentation, I will focus on results of ongoing studies on the influence of features of the urban forest on respiratory problems such as asthma and rhinitis; I will also discuss the influence of the forest on the reduction of air pollution and subsequent respiratory effects. I will put these results in the context of current gaps and controversies in the literature, particularly in relation to the benefits and dis-services of the urban forest for respiratory health.

Moderator: Élise Filotas
Département Science et Technologie, Université TÉLUQ
Researcher at Centre for Forest Research & Quebec Centre for Biodiversity Science