Ecological impact of fire place use in urban forests and consequences for visitor management

Urban forests are popular recreation areas in Europe. At the same time, these forests are important habitats for plants and animals and often harbour a high biodiversity. Recreational activities, for example picnicking and grilling and in particular the creation and usage of fire rings outside official picnic sites ("wild" fire rings), can cause extensive damage to soil and vegetation. Firewood collection depletes woody debris, leading to a loss of habitat for specialized organisms. Economical consequences of forest recreation include maintenance costs of recreational infrastructure and diminishing revenues due to visitor-related damage to trees and subsequent reduction in timber quality. In the present thesis I examined the effects of fire place use on the forest soil, including soil microbial biomass and enzyme activity, ground vegetation, shrubs, trees and amount of woody debris. In addition, the reduction in timber value resulting from recreational damage to trees was estimated. In order to develop and implement measures, it is important to find out why forest visitors create and use "wild" fire rings instead of official picnic sites. Therefore, I conducted a forest visitor survey focusing on visitor preferences concerning fire places. An experiment was conducted with four new fire places designed to fulfil forest visitors' requirements, and a follow-up survey documented visitors' reactions. A survey aimed at forestry experts in the whole of Switzerland provided valuable information on foresters' perceptions concerning the consequences of picnicking and grilling and forest recreation in general. At frequently used fire places we found reduced plant species densities in the ground vegetation and shrub layer and changes in plant species composition. Picnicking and grilling also reduced the height and changed the age structure of shrubs and young trees. The amount of woody debris was lower in disturbed plots than in control plots. Soil microbial biomass (Cmic and Nmic) and dehydrogenase activity were differently affected by short- and long-term trampling. In a short-term experiment, these soil characteristics decreased at low and medium, but not at high trampling frequencies. In contrast, the same soil characteristics decreased with increasing trampling intensity in a long-term field survey at fire places that had been in use for more than a decade. The activity of β-glucosidase was only affected by short-term trampling. Phosphomonoesterase activity was most severely affected by long-term trampling, most probably as a result of the loss of plants. The reduction in timber value due to visitor-related damage to trees ranged from 19 to 53 € per hectare and year in two suburban forests. Total recreationinduced costs, i.e. additional expenses and reductions in timber value exceeded 10% of the total annual expenditures of the two forest enterprises examined. The forest visitor survey revealed a preference for fire places near streams, away from forest roads and close to open spaces. While some visitors highly appreciated the well-equipped official sites, others preferred more natural infrastructure with pieces of stones forming a fire ring rather than concrete rims, and logs to sit on instead of benches. Experimental fire places consisting of a ring of stones and logs fulfilled the needs concerning infrastructure of visitors who normally use "wild" sites. However, the location of fire places was termed more important than their infrastructure. Forestry experts' perceptions regarding reasons for "wild" site creation differed largely from the results of the forest visitor survey. According to experts, an insufficient number of barbecue pits, available firewood and forest visitors seeking adventure and romanticism repeatedly lead to the creation of "wild" fire rings

Urban forest usage and perception of ecosystem services – A comparison between teenagers and adults

We thank Christoph Düggelin and Marc Baume for the interpretation of the photographs and two anonymous reviewers for comments on the manuscript. The project was funded by the Swiss State Secretariat for Education, Research and Innovation SERI, Switzerland (Grant No. C13.0135) as a contribution to the COST Action PF1204 and by the Swiss Federal Office for the Environment, Switzerland (Grant No. 16.0074.PJ / S062-1129).Peer reviewedPublisher PD

A spatial Bayesian network model to assess the benefits of early warning for urban flood risk to people

This article presents a novel methodology to assess flood risk to people by integrating people's vulnerability and ability to cushion hazards through coping and adapting. The proposed approach extends traditional risk assessments beyond material damages; complements quantitative and semi-quantitative data with subjective and local knowledge, improving the use of commonly available information; and produces estimates of model uncertainty by providing probability distributions for all of its outputs. Flood risk to people is modeled using a spatially explicit Bayesian network model calibrated on expert opinion. Risk is assessed in terms of (1) likelihood of non-fatal physical injury, (2) likelihood of post-traumatic stress disorder and (3) likelihood of death. The study area covers the lower part of the Sihl valley (Switzerland) including the city of Zurich. The model is used to estimate the effect of improving an existing early warning system, taking into account the reliability, lead time and scope (i.e., coverage of people reached by the warning). Model results indicate that the potential benefits of an improved early warning in terms of avoided human impacts are particularly relevant in case of a major flood event

Linking demand and supply factors in identifying cultural ecosystem services of urban green infrastructures:A review of European studies

Urban green infrastructure provides a number of cultural ecosystem services that are greatly appreciated by the public. In order to benefit from these services, actual contact with the respective ecosystem is often required. Furthermore, the type of services offered depend on the physical characteristics of the ecosystem. We conducted a review of publications dealing with demand or social factors such as user needs, preferences and values as well as spatially explicit supply or physical factors such as amount of green space, (bio)diversity, recreational infrastructure, etc. and linking demand and supply factors together. The aim was to provide an overview of this highly interdisciplinary research, to describe how these linkages are being made and to identify which factors significantly influence dependent variables such as levels of use, activities or health and well-being benefits. Commonly used methods were the combination of questionnaires with either on-site visual recording of elements or GIS data. Links between social and physical data were usually established either by using statistical tools or by overlaying different thematic maps. Compared to the large number of variables assessed in most studies, the significant effects in the end were relatively few, not consistent across the studies and largely dependent on the context they were seen in. Studies focused on aesthetic and recreational services, while spiritual, educational and inspirational services were not considered when creating links to spatially explicit ecological structures. We conclude that an improvement and harmonization of methodologies, cross-country studies and an expansion of this line of research to a wider range of services and more user groups could help clarify relationships and thereby increase applicability for urban management and planning.</p

Waldnutzung durch Waldkindergärten und Schulen: Chancen und Risiken für den Wald

Kindergärten und Schulen nutzen die Schweizer Wälder vermehrt als Klassenzimmer. Die pädagogische und sozialwissenschaftliche Forschung beschäftigt sich seit vielen Jahren intensiv mit den Auswirkungen des Waldunterrichts auf die persönliche und schulische Entwicklung der Kinder. Es fehlt aber an Forschung und Literatur, die den Einfluss dieser Waldnutzung auf die Vegetation des Waldes und den Erhalt sowie die Entwicklung der Bäume im Bestand untersucht. Im Rahmen einer Bachelorarbeit wurde diese Thematik mittels Feldaufnahmen und Interviews analysiert. Fazit: Der Waldunterricht sollte immer an den gleichen Stellen durchgeführt werden, um negative Einflüsse auf den Wald zu minimieren. Zudem sollten Synergien zwischen den einzelnen pädagogischen Angeboten besser genutzt werden

How do forest visitors perceive forest management forms? Public acceptance of coppice-with-standards in urban forests

To mitigate climate change consequences, a shift to more renewable energy sources is necessary. The traditional forest management form coppice-with-standards features efficient harvesting cycles and could therefore provide a reliant biomass source. Particularly forests close to urban settlements are popular destinations for outdoor recreation. Therefore, for a well-functioning interaction between recreation and forest management, forest visitors' preferences need to be considered. Even though, coppice-with-standards have been studied scientifically from various points of view, including its cultural and ecological values, little focus was put on the perceived visual attractiveness of this management form. Therefore, this study aims to investigate how forest visitors perceive different forest management forms with a focus on coppice-with-standards in the case study area in Zurich, Switzerland by performing qualitative Go-Along interviews and a quantitative forest visitor survey. The statistical analysis revealed that forest visitors have divided opinions on this management form and prefer even-aged high forest as well as continuous forest management. Therefore, in case of an increasing use of coppice-with-standards management for biomass production, implementation in recreational forests needs to be weighed against less frequently visited areas. However, addressing the visitors with well-targeted communication strategies could result in increased understanding and acceptance and could therefore support the implementation process also in recreational forests

Advancing forest inventorying and monitoring

Key message Evolving societal demands and accelerated ecological dynamics due to global change are rapidly altering forest ecosystems and their services. This has prompted the need for advancing forest inventorying and monitoring initatives to expand their scope, improve data collection, foster scientific understanding, and better inform policy responses. Here, we discuss the collaborative processes followed to develop an Advanced Inventorying and Monitoring (AIM) system for Swiss forests. Further, we provide the key messages that emerged from this process which can be of interest to those involved in similar processes at the national/international level