Treesearch

The ignition of small fuel elements plays a crucial role in fire propagation. These fine fuels are often the first to ignite and serve as a bridge for fire spread to larger scenarios. The moisture content of these fuels significantly affects their flammability and thermal behaviour. In this study, the effect of fuel moisture content (FMC) and orientation on the drying, pyrolysis, ignition, and thermal processes of a cellulose solid fuel is investigated through a series of numerical simulations. In addition, experimental ignition-time measurements were conducted at the U.S. Forest Service...

Crib fires are a way to produce fires with higher repeatability than generally is the case for wildland and urban scenarios and consequently are used to study fire behavior. Models for simulating large-scale fires benefit from characterization against relevant test conditions. Here we describe a modeling and experimental effort to better explore fire dynamics at the larger range of what is achievable in laboratories. The modeling that corresponds to the tests is used to provide parameters to larger-scale transport modeling efforts for climate effects as well as to evaluate modeling under...

Wildfires have increasingly affected human and natural systems across the western United States (WUS) in recent decades. Given that the majority of ignitions are human‐caused and potentially preventable, improving the ability to predict fire occurrence is critical for effective wildfire prevention and risk mitigation. We used over 500,000 wildfire ignition records from 2000 to 2020 to develop machine learning models that predict daily ignition probability across the WUS and incorporate a wide range of physical, biological, social, and administrative variables. A key innovation of this work...

Public lands are sources of valuable ecological, social, cultural, economic, scientific, and recreational resources in the United States. Wildfires may threaten the continued provision of some of these benefits. Fire management on public lands is increasingly challenging due to the growing array of human activities responsible for fires, including recreational target shooting. We used detailed information in agency fire reports from 1992 to 2020 to advance our understanding of contemporary wildfire ignition sources and patterns on a subset of public lands managed by the Bureau of Land...

Wildfires are burning more area across the western US than they have in the recent past, driving an increased need for post-fire reforestation. At the same time, trees are struggling to keep up with climate change and post-fire tree planting may present an opportunity to plant seedlings from seed sources adapted to changing conditions. To better understand how reforestation outcomes for an ecologically and economically important conifer species in the northwestern US vary with seed source and site conditions, we conducted a post-fire western larch ( Larix occidentalis ) planting experiment...

The Mendocino National Forest reached out to the public in 2023 and 2024 to understand community connections to the forest and hear ideas about how to recover after recent wildland fires. We heard from 523 people over two months! Over 60% of those who participated had lived in the area for more than 25 years. For over half of participants (54%), this was their first time providing input to the Mendocino National Forest. The M3P tool (Mapping, Prioritization and Public Participation) was used to gather and understand public input. This executive summary provides key highlights from these...

Aquatic ecosystems worldwide face increasing human–wildlife conflicts as fishing activities overlap with critical habitats for vulnerable species. Human–wildlife interactions in artisanal fisheries exemplify socio-ecological systems that necessitate adaptive management approaches, integrating ecological and social dimensions. This study integrates socio-ecological systems theory and quantitative modelling to identify gear-based and attitudinal pathways for coexistence between fishermen and the African manatee (Trichechus senegalensis) in Lake Ossa Wildlife Reserve, Cameroon. We conducted...

Fire is an ecological disturbance that can accelerate nutrient cycling and alter herbivore distribution in grasslands and shrublands. Historically and today, humans have used prescribed fire to enhance forage quality for wild and domestic herbivores, and to achieve other management objectives. Contextual factors such as ecosystem type, seasonality, and fuel characteristics can determine how prescribed fire affects forage quality. For example, forage quality enhancements are relatively short lived in shortgrass steppe and subhumid grasslands but may persist for multiple years in northern...

Plants are an integral part of the Earth’s Critical Zone, linking the atmosphere, hydrosphere, lithosphere, and biosphere (Field et al. 2015). To improve our insights into ecological theory and ecosystem processes, we need a more holistic view of plants that incorporates the “unseen elephant” of belowground plant organs and their traits (Fig. 1). Roots and belowground stems (e.g., rhizomes and tubers) acquire and store nutrients and support belowground buds that enable plants to regenerate following dormant seasons or disturbance (Klimešová and Klimeš 2007). Although belowground plant...

Competitive effects on biomass and vegetative reproduction can be especially strong when plants are young and establishing their clonal network of ramets. Invasive clonal plants may mitigate the effects of competition better than native clonal plants. We evaluated the competitive effects on the propagule supply and the number and biomass of tillers and rhizomes of invasive (Bromus inermis) and native (Pascopyrum smithii) perennial grass seedlings. Competition reduced aboveground biomass and the number of tillers for both species in most competitive scenarios, except for B. inermis under...