Search

Wildfire in peatlands is of global importance due to the risk of direct carbon release. While considerable attention is given to carbon release, other wildfire impacts and indirect risks, such as the impact on soil pH, remain less studied. Peatlands characteristically require acidic conditions (soil pH ≤ 4.5) for optimal functioning. However, wildfire-produced ash often has a high pH and ash input into soil could potentially increase soil pH.We studied a wildfire in a raised-bog peatland in the south of the Netherlands – where considerable peat smoldering and ash production occurred – by combining field observations with lab experiments. We measured the pH of topsoil and ash samples, which were collected from the area approximately two months after the wildfire. A smoldering experiment with peat was done to estimate the alkalinity in freshly produced ash (herein: ‘fresh ash’) and to able to compare it to ash collected in the field (herein: 'aged ash'). Finally, the amount of fresh ash needed to increase soil pH was quantified in an incubation and titration experiment with ash and peat soil.All topsoil samples collected from the field were acidic (pH ~3-4), even in sampling locations with ash present. Fresh ash produced in the smouldering experiment was alkaline, while aged ash collected during field work was slightly acidic. This indicates that alkalinity was likely leached from the ash by the time of field work. The incubation experiments showed that a ≥3 cm ash layer is needed to increase soil pH by at least 1 unit. Results suggest that ash, when produced in high enough quantity, can change peatland soil pH. However, dilution and ageing of the ash after a wildfire, as likely occurred in our field site, will constrain the period of elevated soil pH after wildfires and subsequent ash input. This transit increase in soil pH suggests that even wildfires with considerable ash production do not lead to increased soil pH.

There is a growing recognition that there needs to be a shift from firefighting to wildfire prevention (through fuel and landscape management and engagement with stakeholders) of which disaster risk reduction plays a major role. In the Netherlands, where flood and water has been centrally managed from 1798, there has been a shift from fighting against water (disaster management) to flood risk reduction and living with water. The same approach is needed in integrated fire management and thus there are lessons that can be learnt from this for society, agencies and government. Integrated fire management which consists of science-based decision making by multidisciplinary teams through cooperation and collaboration of parties involved and affected. Fire science is multi-disciplinary and needs to be addressed in a multi-disciplinary manner. Challenges faced in both sectors are similar in terms of scale, governance and engaging with society. A systematic literature review lead to the identification of lessons from Dutch water management and Room for the River Programme that may be applied to integrated fire management. In the Netherlands there is a recognition that (flood) risk management should be a programmed, flexible process of continuous improvement of management practices by active learning about current interventions and drivers of change. The expected results will provide guidance on how to improve prevention of wildfires within Integrated Fire Management.

In recent years fires of greater magnitude have been documented throughout northwest Europe, and with several climate projections indicating future increases in fire activity in this temperate area, it is imperative to identify the status of fire in this region. This study unravels important unknowns about the state of the fire regime in northwest Europe by characterizing one of the key aspects of fire behavior, the rate of spread (ROS). Using an innovative approach to cluster VIIRS hotspots into fire perimeter isochrones to derive ROS, we identify the effects of land cover and season on fire rate of spread of 254 landscape fires that occurred between 2012 and 2020. Results reveal no significant differences between land cover types and there is a clear peak of ROS and burned area in the months of April and May. During this late spring period, 67 % of the burned area occurs and median fire runs are approximately 0.16 km/hr during a 12 hour overpass. Heightened ROS and burned area values persist in the bordering months of March and June suggesting that may present the extent of the fire season in northwestern Europe. Accurate data on ROS among the represented land cover types as well as periods of peak activity are essential for determining periods of elevated fire risk, the effectiveness of available suppression techniques as well as appropriate mitigation strategies (land and fuel management).

Climate change is expected to alter fire regimes but also rainfall patterns. Fire is a natural process that removes vegetation and may affect soil properties, resulting in changes in overland flow and streamflow generation. Some fires cause erosion and may even cause destructive debris flow and other events, which can not only threaten lives and property but also leave lasting imprints in landscapes. The geomorphological response after fire events is a complex function of pre-fire landscape and vegetation properties, fire behavior and effects, and post-fire rainfall timing, duration and intensity. In this talk, I highlight these processes using examples of past events, and explore geomorphological response to fires in a future where both fire and rainfall may be be rather different.

As professionals who study the control and prevention of wildfires, we argue that reducing the resulting loss of life and property calls for the involvement of socially diverse local communities. People from different cultural backgrounds respond differently to wildfire risk, as do men and women (C. Eriksen Gender and Wildfire: Landscapes of Uncertainty; Routledge, 2013). This presents practical and policy challenges for firefighting agencies. For instance, fire prevention and emergency warning must be tailored to specific groups. And engagement with local communities could be an awkward fit with wildland firefighting institutions, which are strongly hierarchical and have a masculine culture (A. M. S. Smith and E. K. Strand Fire 1, 45; 2018). Fire-prevention strategies should include public education and real-time mass communication (see also A. M. S. Smith et al. Bioscience 66, 130–146; 2016). Communities need advice on managing fire risk. This requires devolution of political power from centralized bureaucracies to local organizations, and promotion of disciplinary, sectoral and social diversity among fire scientists, policymakers and wildfire managers.

Media such as television, newspapers and social media play a key role in the communication between scientists and the general public. Communicating your science via the media can be positive and rewarding by providing the inherent joy of sharing your knowledge with a broader audience, promoting science as a fundamental part of culture and society, impacting decision and policy makers, and giving you a greater recognition by institutions, colleagues and funders. However, the interaction between scientists and journalists is not always straightforward. For instance, scientists may not always be able to translate their work into a compelling story, and journalists may sometimes misinterpret scientific output. In this paper, we present insights from hydrologists and journalists discussing the advantages and benefits as well as the potential pitfalls and aftermath of science-media interaction. As we perceive interacting with the media as a rewarding and essential part of our work, we aim to encourage scientists to participate in the diverse and evolving media landscape. With this paper, we call on the scientific community to support scientists who actively contribute to a fruitful science-media relationship.