Spatial Analysis For Conservation and Sustainability
Fire
Fire is now lacking in many ecosystems that require it, yet fire is also a dire threat to lives, homes, and livelihoods. Due to climate and land use change, fire frequency has risen in recent decades, and we study how societies and communities can better live with fire, and where to restore fire regimes.
Every year, wildfires destroy thousands of buildings in the United States, especially in the rapidly growing wildland-urban interface, where homes and wildland vegetation meet or intermingle. After a wildfire there is a window of opportunity for residents and public agencies to re-shape patterns of development, and avoid development in locations that are inherently at higher risk of wildfire destruction. We examined 28 of the most destructive wildfires in California, the state where most buildings are destroyed by wildfires, to evaluate whether locations of rebuilt and newly constructed buildings were adaptive (i.e., if building occurred in lower risk areas). In total, these fires burned 7,075 buildings from 1970 to 2009. We found minimal evidence for adaptation both in the number and placement of buildings post-fire. Rebuilding was common: 58% of the destroyed buildings were rebuilt within three to six years, and 94% within thirteen to twenty-five years after the fire. Similarly, we found minimal trends toward lower risk areas in the placement of 2,793 rebuilt and 23,404 newly constructed buildings over the course of 13–25 yr. In fact, long-term data revealed that relative risk of new construction either did not change significantly over time or increased. A destructive wildfire could provide an opportunity to assess and change building practices, yet our results show that such change is largely not occurring. As wildfires increasingly threaten communities, this lack of change could result in growing rates of destruction and loss of life.
Peatland fires can be some of the most catastrophic and expensive fires globally, including in the Great Lakes Region where wildfires in the mid-2000s burned through tens of thousands of acres in Michigan peatlands, and in 1976, when the Seney Fire burned for months underground consuming peat. Deep burning peatland fires can lead to the conversion and the permanent loss of peatlands, which are important refugias for plant and animal species. Such fires, however, have been infrequent since European settlement, and are assumed to have occurred only every few centuries or millennia. We investigated fire in peatlands to determine if historically fire in peatlands was indeed infrequent and severe.
Map of three peatland sites sampled across the Great Lakes Region in Wisconsin and Michigan.
Between 2017 and 2019, we collected samples from 220 fire-scarred trees in three peatlands within the Hiawatha and Chequamegon-Nicolet National Forests in the Great Lakes Region. Our sites were poor fen peatlands intermixed with dry to dry-mesic northern forests. We identified 141 fire years from 1548 to 1955. Prior to 1955 fires were historically frequent across our peatland sites occurring on average every 7 to 34 years depending on the site sampled. By using fire-scarred tree samples to investigate historical fire, we could identify fires that were likely low- to moderate-severity because fire scars are indicative of more frequent, low-severity fire whereas high-severity fires would have consumed most trees rather than just scarring them. We did not detect any fires after 1955, corresponding to the period when fire suppression efforts of the United States Forest Service became increasingly effective.
Fire-scarred tree sample including fires in 1734, 1755, and 1792 and the corresponding position (dormant or latewood) of the fire scar in individual tree rings.
Historically, fire was frequent in the peatlands we investigated and our research warrants rethinking of the role of fire in these ecosystems. Such a rethinking could have major implications on how managers use prescribed fire and mitigate wildfire risk in peatlands. Fire suppression since the mid-1900s in Great Lakes’ peatlands likely has unintended consequences including the encroachment of undesirable vegetation into open bogs and fens that were historically maintained by frequent fires over hundreds of years. Furthermore, it is possible that by removing frequent fire from peatlands in the Great Lakes Region these systems could become more prone to more severe, catastrophic fires that burn deep consuming peat soils. A possible mechanism for such a shift may be encroaching vegetation drawing more water from peat soils making them more susceptible to burning under severe drought conditions. Repeated prescribed burning under the more moderate conditions (e.g., surface vegetation of the peatlands is dry, but the peat soils are inundated with water) could be one approach to prevent encroachment and maintaining low-severity fire regimes. Fire management in peatlands of the Great Lakes Region needs to include rethinking the role of fire, considering it not just as a threat but also as a potential tool.
Collaborators: Jed Meunier (Wisconsin DNR) and Eric Rebitzke (US Forest Service)
Public lands provide many ecosystem services and support diverse plant and animal
communities. In order to provide these benefits in the future, land managers and policy
makers need information about future climate change and its potential effects. In particular,
weather extremes are key drivers of wildfires, droughts, and false springs, which in turn can
have large impacts on ecosystems. However, information on future changes in weather
extremes on public lands is lacking. Our goal was to compare historical (1950–2005) and projected
mid-century (2041–2070) changes in weather extremes (fire weather, spring droughts,
and false springs) on public lands. This case study looked at the lands managed by the U.S.
Forest Service across the conterminous United States including 501 ranger district units. We
analyzed downscaled projections of daily records from 19 Coupled Model Intercomparison
Project 5 General Circulation Models for two climate scenarios, with either medium-low or
high CO2 equivalent concentration (RCPs 4.5 and 8.5). For each ranger district, we estimated:
(1) fire potential, using the Keetch-Byram Drought Index; (2) frequency of spring
droughts, using the Standardized Precipitation Index; and (3) frequency of false springs, using
the extended Spring Indices. We found that future climates could substantially alter weather
conditions across Forest Service lands. Under the two climate scenarios, increases in wildfire
potential, spring droughts, and false springs were projected in 32–72%, 28–29%, and 13–16%
of all ranger districts, respectively. Moreover, a substantial number of ranger districts
(17–30%), especially in the Southwestern, Pacific Southwest, and Rocky Mountain regions,
were projected to see increases in more than one type of weather extreme, which may require
special management attention. We suggest that future changes in weather extremes could
threaten the ability of public lands to provide ecosystem services and ecological benefits to
society. Overall, our results highlight the value of spatially-explicit weather projections to
assess future changes in key weather extremes for land managers and policy makers.
Globally, and in the US, wildfires pose increasing risk to people and their homes. Wildfire management
assumes that buildings burn primarily in the wildland–urban interface (WUI), where homes are either ignited directly
(especially in intermix WUI areas, where houses and wildland fuels intermingle), or via firebrands, the main threat to
buildings in the interface WUI (areas with minimal wildland fuel, yet close to dense wildland vegetation). However, even
urban areas can succumb to wildfires. We examined where wildfire damages occur among urban, rural and WUI (intermix
and interface) areas for approximately three decades in California (1985–2013). We found that interface WUI contained
50% of buildings destroyed by wildfire, whereas intermix WUI contained only 32%. The proportion of buildings destroyed
by fires among classes was similar, though highest in interface WUI areas (15.6%). Our results demonstrate that the
interface WUI is where most buildings were destroyed in California, despite less wildland fuel. Continued advancement of
models, mitigation and regulations tailored for the interface WUI, both for California and elsewhere, will complement the
prior focus on the intermix WUI.
Globally, and in the US, wildfires pose increasing risk to people and their homes. Wildfire management
assumes that buildings burn primarily in the wildland–urban interface (WUI), where homes are either ignited directly
(especially in intermix WUI areas, where houses and wildland fuels intermingle), or via firebrands, the main threat to
buildings in the interface WUI (areas with minimal wildland fuel, yet close to dense wildland vegetation). However, even
urban areas can succumb to wildfires. We examined where wildfire damages occur among urban, rural and WUI (intermix
and interface) areas for approximately three decades in California (1985–2013). We found that interface WUI contained
50% of buildings destroyed by wildfire, whereas intermix WUI contained only 32%. The proportion of buildings destroyed
by fires among classes was similar, though highest in interface WUI areas (15.6%). Our results demonstrate that the
interface WUI is where most buildings were destroyed in California, despite less wildland fuel. Continued advancement of
models, mitigation and regulations tailored for the interface WUI, both for California and elsewhere, will complement the
prior focus on the intermix WUI.
Over the past 30 years, the cost of wildfire suppression and homes lost to wildfire in the U.S. have increased dramatically, driven in part by the expansion of the wildland-urban interface (WUI), where buildings and wildland vegetation meet. In response, the wildfire management community has devoted substantial effort to better understand where buildings and vegetation co-occur, and to establish outreach programs to reduce wildfire damage to homes. However, the extent to which the location of buildings affected by wildfire overlaps the WUI, and where and when outreach programs were established relative to wildfire, is unclear. We found that most threatened and destroyed buildings in the conterminous U.S. were within the WUI (59% and 69%, respectively), but this varied considerably among states. Fires with the greatest building loss were close to outreach programs (such as Firewise), but for 76% of destroyed buildings, the nearest outreach program was established post-wildfire. In these locations, as well as places new to the WUI or in areas where the fire regime is predicted to change, pre-emptive outreach could improve the likelihood of building survival and reduce the human and financial costs of structure loss.
Wildfires are a major threat to people and property in Wildland Urban Interface (WUI) communities
worldwide, but while the patterns of the WUI in North America, Europe and Oceania have been studied
before, this is not the case in Latin America. Our goals were to a) map WUI areas in central Argentina, and
b) assess wildfire exposure for WUI communities in relation to historic fires, with special emphasis on
large fires and estimated burn probability based on an empirical model. We mapped the WUI in the
mountains of central Argentina (810,000 ha), after digitizing the location of 276,700 buildings and
deriving vegetation maps from satellite imagery. The areas where houses and wildland vegetation
intermingle were classified as Intermix WUI (housing density > 6.17 hu/km2 and wildland vegetation
cover > 50%), and the areas where wildland vegetation abuts settlements were classified as Interface
WUI (housing density > 6.17 hu/km2, wildland vegetation cover < 50%, but within 600 m of a vegetated
patch larger than 5 km2). We generated burn probability maps based on historical fire data from 1999 to
2011; as well as from an empirical model of fire frequency. WUI areas occupied 15% of our study area and
contained 144,000 buildings (52%). Most WUI area was Intermix WUI, but most WUI buildings were in
the Interface WUI. Our findings suggest that central Argentina has a WUI fire problem. WUI areas
included most of the buildings exposed to wildfires and most of the buildings located in areas of higher
burn probability. Our findings can help focus fire management activities in areas of higher risk, and
ultimately provide support for landscape management and planning aimed at reducing wildfire risk in
WUI communities.
The process of vegetation burning is an essential component in the dynamics of grassy arid ecosystems. An understanding of the impact of fires on various components of the arid ecosystem is required for scientific, environmental, and management tasks, and it should be assessed with a high spatial and temporal resolution. This paper presents a method and description of data to be used in such an assessment of fire dynamics. The spatiotemporal dynamics of fires in the Chernye Zemli area is described. It shows the abundance of fires, their high interannual variability, clusterization in a territory, and the dominance of large fires.
The hazards-of-place model posits that vulnerability to environmental hazards depends on both biophysica and social factors. Biophysical factors determine where wildfire potential is elevated, whereas social factors determin where and how people are affected by wildfire. We evaluated place vulnerability to wildfire hazards in the coterminou US. We developed a social vulnerability index using principal component analysis and evaluated it against existin measures of wildfire potential and wildland–urban interface designations. We created maps showing the coincidence o social vulnerability and wildfire potential to identify places according to their vulnerability to wildfire. We found tha places with high wildfire potential have, on average, lower social vulnerability than other places, but nearly 10% of al housing in places with high wildfire potential also exhibits high social vulnerability. We summarised our data by states t evaluate trends at a subnational level. Although some regions, such as the South-east, had more housing in places with hig wildfire vulnerability, other regions, such as the upper Midwest, exhibited higher rates of vulnerability than expected. Ou results can help to inform wildfire prevention, mitigation and recovery planning, as well as reduce wildfire hazard affecting vulnerable places and populations.
One challenge in the effort to conserve biodiversity is identifying where to prioritize resources for active land management. Cost–benefit analyses have been used successfully as a conservation tool to identify sites that provide the greatest conservation benefit per unit cost. Our goal was to apply cost–benefit analysis to the question of how to prioritize land management efforts, in our case the application of prescribed fire to natural landscapes in Wisconsin, USA. We quantified and mapped frequently burned communities and prioritized management units based on a suite of indices that captured ecological benefits, management effort, and the feasibility of successful long- term manage-ment actions. Data for these indices came from LANDFIRE, Wisconsin’s Wildlife Action Plan, and a nationwide wildland–urban interface assessment. We found that the majority of frequently burned vegetation types occurred in the southern portion of the state. How-ever, the highest priority areas for applying prescribed fire occurred in the central, north-west, and northeast portion of the state where frequently burned vegetation patches were larger and where identified areas of high biological importance area occurred. Although our focus was on the use of prescribed fire in Wisconsin, our methods can be adapted to prioritize other land management activities. Such prioritization is necessary to achieve the greatest possible benefits from limited funding for land management actions, and our results show that it is feasible at scales that are relevant for land management decisions.
