Report
Teaser, summary, work performed and final results
Periodic Reporting for period 1 - Ko-Tsah-To (Temperatures, ash and soil hydrology: predicting fire impact from plant traits)
Teaser
Climate change increases the frequency and intensity of vegetation fires around the world. Fire can considerably increase the landscape’s vulnerability to flooding and erosion, which is in part caused by fire-induced soil damage and hydrological changes. While it is known...
Summary
Climate change increases the frequency and intensity of vegetation fires around the world. Fire can considerably increase the landscape’s vulnerability to flooding and erosion, which is in part caused by fire-induced soil damage and hydrological changes. While it is known that plants can alter the fire environment, there is a major knowledge gap regarding the fundamental mechanisms by which vegetation mediates fire impact on soil physics and hydrology. I addressed this gap by considering for the first time the cascading effects of plants on fire and soil hydrology, focusing on two important factors in post-fire hydrology: soil heating and ash. My hypothesis is that plant structural and chemical traits vary within the landscape and control fire impact on soil physical properties by affecting heat and ash production. I tested this hypothesis with a combination of spatial sampling, lab experiments and modeling, using contrasting plant species and soils from watersheds in Portugal and the Navajo Nation (USA). Results indicate that plant flammability traits vary in the landscape, with implications for both soil heating and ash. I found that ash production and size is highly affected by the duration of smouldering combustion, and that loosely packed fuels (like standing fuels) therefore produce coarser ash than more densely packed fuels like litter beds. Within these fuel types, both plant species and fuel moisture content were important controls. These findings can help predict and mitigate fire risk and impact across landscapes, facilitate development of risk maps, and generate knowledge with implications for nature conservation, land use planning, fire management, safeguarding of water quality, and potential policy making. The training and research opportunities provided by this project changed a European braindrain into a braingain, supporting reintegration of a successful interdisciplinary scientist and her large network after three years in the USA. Through this reintegration I have been able to: 1) build my European network of interdisciplinary and intersectoral collaborators, 2) conduct original and innovative interdisciplinary research, 3) secure a permanent position as a tenured Assistant Professor at a leading European University, and 4) solidify my science communication and outreach by working with highly respected national and international media as well as with local and indigenous communities. As such, Marie Curie funding has opened up both a novel research line as well as the basis for new interdisciplinary and intersectoral collaborations in the soil and fire sciences which this summer has showed is highly needed in this changing climate.
Work performed
Work centered around three large field campaigns, in Portugal, on the Navajo Nation (USA), and the UK. Methods were tested in Portugal, where I studied the spatial variability of flammability by measuring the amount of live and dead fuel (vegetation) and modeled resulting fire behavior. Results showed that flammability and resulting soil heating varies in the landscape and that because of human disturbance on fuels it cannot be easily predicted from readily available topographic information. Navajo Nation fieldwork focused on determining plant flammability traits in relation to quantitative fire metrics (time to ignition, heat release, flaming duration, smouldering duration), to calibrate ecological approaches. UK fieldwork addressed the flammability of temperate species during the extreme 2018 summer drought, in light of expected shifts in fire regime towards more temperate regions.
All plant material collected in these field campaigns was experimentally burned to measure fire metrics and quantify and analyze resulting ash. This showed the importance of species differences and packing effects on ash production, and a strong effect of smouldering combustion. The ash characteristics along with existing data on ash and soil textures was used to determine hydrological effects of ash for a wide range of soil types using modeling approaches typically used in irrigation and drainage research (WP4).
The project has produced two peer-reviewed publications (with four more being finalized), participation in nine international workshops/conferences (thirteen oral and poster presentations by my students and me), an integrated science-stakeholder workshop, seminar for an indigenous summer school, interaction with four EU projects, my listing as a ‘local hero’ in the EU PROTECTS awareness campaign and in a book on 22 inspirational women in science, three new grant proposals, and a large number of tv and radio interviews and written press in the 2017 and 2018 fire seasons.
Final results
This project considered for the first time the cascading effects of plant ecology and traits on fire behavior and resulting soil impacts. It combined soil science, hydrology, fire science and ecology to bridge gaps between these fields and further the understanding of interdisciplinary linkages. Aside from moving beyond the state-of-the-art, this project has had and will continue to have a major impact on my career. I acquired new research competences in ecology and fire sciences, transferable skills on grant writing, project management, intersectoral transfer of knowledge, and strengthened my leadership skills. This project allowed me to travel and build a new European network of interdisciplinary researchers, with whom I am already pursuing follow up funding for joint projects. I solidified these achievements by securing a permanent position three years earlier than anticipated. For Europe, this project has strengthened ties between northern and southern member states in a time where it is clear that we need to do more to prepare ourselves for current and future shifts in fire regimes. I was able to integrate my American network and expertise into my new European network, which means that I am now ready to lead a large interdisciplinary intersectoral grant application with strong ties within and outside Europe. This benefits both European research and innovation capacity, as well as provides essential opportunities to ensure we are able to manage the impact of the wilder wildfires we are seeing now. This project has and will therefore benefit scientists from the fields of soil science, hydrology, ecology and fire science, indigenous and other local communities, fire services and land managers, and policy makers.