Supporting Nature-Based Solutions via Nature-Based Thinking across European and Latin American cities.

Nature-Based Solutions concepts and practices are being used worldwide as part of attempts to address societal challenges but have also been criticised for not dealing with deeper transformations needed to face urgent issues including biodiversity loss, climate change and inclusion. In this paper, we explore how an inclusive, integrated and long-sighted approach, emphasising a more radical integration of nature within cities, might support the transformations needed to endure major contemporary challenges. Addressing important emerging critiques of Nature-Based Solutions, we consider the potential of a more incisive form of Nature-Based Thinking (NBT) in cities, based on more holistic perspectives. The paper draws on a reflective and iterative research process that engaged both the research and practice communities through a symposium and a series of futures workshops that together explored the potential of NBT to develop future nature-cities relations in Europe and Latin America. The results of the reflective process suggest that notions of nature with people-not for people- new organisational structures, and the intention and capacity to apply long-term perspectives, are needed when planning for NBS interventions aimed at sustainable urban development. This includes developing a cultural-structural change based on new and inclusive understandings of human-nature relations, and novel governance paradigms that allow cross-sectoral coordination and engagement of local stakeholders beyond formal organisational structures.

Evidence-Based Integrated Analysis of Environmental Hazards in Southern Bolivia.

The "Valles Cruceños" rural region plays a fundamental role for securing food and other resources for the neighboring, and fast sprawling, city of Santa Cruz de la Sierra (Bolivia). Due to the increasing pressure on its natural resources, the region is affected by progressive and severe environmental degradation, as many other rural regions in South and Central America. In this situation, sound policies and governance for sustainable land management are weak and not supported by data and scientific research outputs. With the present study, we aim at developing a novel and practical integrated hazard analysis methodology, supporting the evidence-based understanding of hazard patterns and informing risk assessment processes in the urban-rural continuum. Firstly, the main environmental hazards affecting the area were identified via questionnaire campaigns, held by the staff of local municipalities. Focusing on the hazards mostly perceived by the inhabitants of the region, including deforestation, water pollution and precipitation changes, hazard maps were created by using multiple environmental hazards indicators. An integrated hazard map was then built in a GIS environment, after a pair-wise comparison process. The maps represent a first baseline for the analysis of the present status of natural resources in "Valles Cruceños" area, and the proposed approach can be scaled up for integrated environmental hazards analysis in similar areas of Latin America.

Fog collection as a strategy to sequester carbon in drylands.

Advection fog is the sole source of water for many near-the-sea arid areas worldwide such as the lomas, i.e. fog-dependant landscapes of the coastal zone of Peru and Northern Chile, where deforestation occurred since 16th century, leading to a progressive and severe desertification. There, today's local socio-ecological systems suffer from lack of freshwater because they cannot rely anymore on the contribution of fog captured by vegetation. This paper presents the results of an experimental reforestation project carried out in Mejia (Peru), where tree seedlings of five native and exotic species were planted in two permanent plots in 1996. Part of the seedlings were irrigated during the first three years after planting, others not. The irrigation was carried out thanks to water harvesting by large fog collectors. From the third year onwards, all trees relied only on fog water collected by their canopy. Survival rate, height, and root-collar diameter were monitored until 2010, when also the soil carbon and nitrogen stocks were measured. Fifteen years after the planting, about 65% of trees were still alive and growing, and reforestation had induced substantial carbon sequestration both above- and below-ground. Of the tree species, Acacia saligna was definitely best performing than the other, with most of the above ground carbon stored in its biomass and a consequent high efficiency as natural fog collector. Overall, the combination of fog collection by nets and the plantation of trees showing good fog collection capacity, represented a successful strategy for allowing reforestation of arid environments and induced fast and substantial carbon sequestration. Greater efforts should be thus devoted for this purpose, paying special attention to the selection of the most suitable tree species to plant, especially looking at the local biodiversity. This work is dedicated to the memory of Professor Mario Falciai, passed away in 2015, who firstly conceived the experiment and attended all the work since 1996, bringing in our University the idea of Fog Collection for sustainable water management.

A tree from waste: Decontaminated dredged sediments for growing forest tree seedlings.

The sediments dredged from a waterway and decontaminated through a phytoremediation process have been used as substrates alternatively to the traditional forest nursery substrate for pot productions of holm oak (Quercus ilex L.) planting stocks. The substrates, made by mixing decontaminated sediments to agricultural soil at different degrees, were tested in order to evaluate their suitability as growth substrates. The experiment was carried out at the nursery of the Department of Agricultural, Food and Forestry Systems of the University of Florence (Italy). The experimental design consisted of four randomized blocks with six pots as replicates for each of the following treatments: 100% sediments, 66% sediments, 33% sediments, 100% agronomic soil and 100% traditional peat based substrate. In each pot, one holm oak acorn was seeded. Germination and both physiological and morphological traits of the seedlings were analysed during and at the end of the first growing season. Holm oak grown in phytoremediated sediments at higher concentrations showed germination levels comparable to those in the traditional substrate, and survival capacity (especially in 66% sediments) slightly higher than in 100% soil. Physiological performance of seedlings resembled that on the traditional substrate which required the addition of fertilizer, at least for the first growing season. Seedlings grown in mixed substrates with higher sediment concentrations occasionally showed better photosynthetic capacity with improved connectivity between the units of the photosystem II. At the end of the first growing season, height as well as the number of growth flushes of the seedlings grown in sole sediment or soil-sediment substrates were similar to what generally is observed for forest nursery stock of Quercus spp.. Regarding the root-system articulation and growth in depth, results in the mixed substrates were comparable to those for seedlings grown in the traditional forest nursery media, and higher than seedlings grown in 100% agronomic soil. According to our results, the reclamation of dredged sediments can provide appropriate nursery substrate for germination beds for forestry species.

A Different Way to Stay in Touch with 'Urban Nature': The Perceived Restorative Qualities of Botanical Gardens.

Botanical gardens represent interesting arenas for research in environmental psychology and environment-behavior relations. They can be considered a very particular type of restorative environment and also have a relevant social function for the promotion of a more sustainable lifestyle in current societies. In this paper, we present a study assessing the relationship between the perceived restorativeness, the psychological and physical benefits experienced, and the subjective well-being reported by visitors of botanical gardens in four different cities in Italy (N = 127). As expected, a bootstrapping mediation model supported the idea that perceived restorativeness of botanical gardens significantly predicts visitors' subjective well-being, both directly and indirectly through perceived physical and psychological benefits of the visit. A moderation model also revealed that the relationship between restorativeness and well-being varies across respondents with different socio-demographic characteristics, being stronger for singles as compared to couples with and without children, respectively. The theoretical and practical implications of these findings are discussed.