Kevin C. Ryan

Remote Sensing of Forest Fire Severity and Vegetation Recovery

Burned forested areas have patterns of varying burn severity as a consequence of various topographic, vegetation, and meteorological factors. These patterns are detected and mapped using satellite data. Other ecological information can be abstracted from satellite data regarding rates of recovery of vegetation foliage and variation of burn severity on different vegetation types. Middle infrared wavelengths are useful for burn severity mapping because the land cover changes associated with burning increase reflectance in this part of the electromagnetic spectrum. Simple stratification of Landsat Thematic Mapper data define varying classes of burn severity because of changes in canopy cover, biomass removal, and soil chemical composition. Reasonable maps of burn severity are produced when the class limits of burn severity reflectance are applied to the entire satellite data. Changes in satellite reflectance over multiple years reveal the dynamics of vegetation and fire severity as low burn areas have lower changes in reflectance relative to high burn areas. This results as a consequence of how much the site was altered due to the burn and how much space is available for vegetation recovery. Analysis of change in reflectance across steppe, riparian, and forested vegetation types indicate that fires potentially increase biomass in steppe areas, while riparian and forested areas are slower to regrow to pre-fire conditions. This satellite-based technology is useful for mapping severely burned areas by exploring the ecological manifestations before and after fire.

Modeling postfire conifer mortality for long-range planning

A model is presented for predicting mortality of conifers after wildfire. The model requires stand data inputs and is linked with a mathematical fire behavior model that calculates fireline intensity. Fraction of crown volume killed is calculated for each species in a stand based on mensurational data. Duration of lethal heat at the base of trees is calculated from fuel consumption and burning time values. Fraction of crown volume killed and the ratio of critical time for cambial kill to duration of lethal heat are independent variables in a function that calculates probability of mortality. The model produces reasonable estimates of stand mortality for fire and site characteristics found in the northern Rocky Mountains, USA. It has a broad resolution appropriate for use in fire management planning and has potential applications for coniferous forests throughout the United States.

Assessing simulated ecosystem processes for climate variability research at Glacier National Park, USA

Glacier National Park served as a test site for ecosystem analyses that involved a suite of integrated models embedded within a geographic information system. The goal of the exercise was to provide managers with maps that could illustrate probable shifts in vegetation, net primary production (NPP), and hydrologic responses associated with two selected climatic scenarios. The climatic scenarios were (a) a recent 12-yr record of weather data, and (b) a reconstituted set that sequentially introduced in repeated 3-yr intervals wetter–cooler, drier–warmer, and typical conditions. To extrapolate the implications of changes in ecosystem processes and resulting growth and distribution of vegetation and snowpack, the model incorporated geographic data. With underlying digital elevation maps, soil depth and texture, extrapolated climate, and current information on vegetation types and satellite-derived estimates of leaf area indices, simulations were extended to envision how the park might look after 120 yr. The p...

Factors affecting sustained smouldering in organic soils from pocosin and pond pine woodland wetlands

The smouldering combustion of peat and muck soil plays an important role in the creation and maintenance of wetland communities. This experimental study was conducted to improve our understanding of how moisture and mineral content constrain smouldering in organic soil. Laboratory burning was conducted with root mat and muck soil samples from pocosin and pond pine woodland wetlands common on the North Carolina coastal plain. The results of laboratory and prescribed burning were compared. Laboratory results showed that moisture and mineral content influenced sustained smouldering in root mat soils. Predictions based on logistic regression analysis show that root mat soils with an average mineral content of 4.5% had an estimated 50% probability of sustained smouldering at a moisture content of 93%, whereas at moisture contents above 145% the estimated probability was less than 10%. The odds that root mat soil will sustain smouldering decrease by 19.3% for each 5% increase in moisture content. Root mat soils with an average mineral content of 5.5% and a moisture content of 93% had an estimated 61% probability of sustained smouldering. The odds that root mat soil will sustain smouldering combustion increased by 155.9% with each 1% increase in mineral content. Root mat and muck soils differ in physical and chemical characteristics expected to influence smouldering behaviour. The formation of muck soil has led to increases in density, smaller soil particle size, changes in water holding characteristics and increases in waxes, resins and bituminous compounds. Muck soil smouldered at higher moisture contents than root mat soil. Muck soil at a moisture content of 201% had an estimated 50% probability of sustained smouldering, whereas at moisture contents above 260% the estimated probability was less than 10%. The odds that muck soil will sustain smouldering combustion decrease by 17.2% with each 5% increase in moisture content. Ground fire in the prescribed burns stopped its vertical spread in organic soils at moisture contents consistent with logistic regression predictions developed from our laboratory results.

Spatial fuel data products of the LANDFIRE Project.

The Landscape Fire and Resource Management Planning Tools (LANDFIRE) Project is mapping wildland fuels, vegetation, and fire regime characteristics across the United States. The LANDFIRE project is unique because of its national scope, creating an integrated product suite at 30-m spatial resolution and complete spatial coverage of all lands within the 50 states. Here we describe development of the LANDFIRE wildland fuels data layers for the conterminous 48 states: surface fire behavior fuel models, canopy bulk density, canopy base height, canopy cover, and canopy height. Surface fire behavior fuel models are mapped by developing crosswalks to vegetation structure and composition created by LANDFIRE. Canopy fuels are mapped using regression trees relating field-referenced estimates of canopy base height and canopy bulk density to satellite imagery, biophysical gradients and vegetation structure and composition data. Here we focus on the methods and data used to create the fuel data products, discuss problems encountered with the data, provide an accuracy assessment, demonstrate recent use of the data during the 2007 fire season, and discuss ideas for updating, maintaining and improving LANDFIRE fuel data products.

Research and development supporting risk-based wildfire effects prediction for fuels and fire management: status and needs

Wildland fire management has moved beyond a singular focus on suppression, calling for wildfire management for ecological benefit where no critical human assets are at risk. Processes causing direct effects and indirect, long-term ecosystem changes are complex and multidimensional. Robust risk-assessment tools are required that account for highly variable effects on multiple values-at-risk and balance competing objectives, to support decision making. Providing wildland fire managers with risk-analysis tools requires a broad scientific foundation in fire behaviour and effects prediction as well as high quality computer-based tools and associated databases. We outline a wildfire risk-assessment approach, highlight recent developments in fire effects science and associated research needs, and recommend developing a comprehensive plan for integrated advances in wildfire occurrence, behaviour and effects research leading to improved decision support tools for wildland fire managers. We find that the current state of development in fire behaviour and effects science imposes severe limits on the development of risk-assessment technology. In turn, the development of technology has been largely disconnected from the research enterprise, resulting in a confusing array of ad hoc tools that only partially meet decision-support needs for fuel and fire management. We make the case for defining a common risk-based analytic framework for fire-effects assessment across the range of fire-management activities and developing a research function to support the framework.

Fire and fire ecology: Concepts and principles

Fire has been central to terrestrial life ever since early anaerobic microorganisms poisoned the atmosphere with oxygen and multicellular plant life moved onto land. The combination of fuels, oxygen, and heat gave birth to fire on Earth. Fire is not just another evolutionary challenge that life needed to overcome, it is, in fact, a core ecological process across much of the planet.

Eight-year tree growth following prescribed underburning in a western Montana Douglas-fir/western larch stand

Eight-year tree growth of western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii) was measured following prescribed underburning on burned and control plots in western Montana. Western larch on bun.ed plots had reduced radial growth in the first year following fire but increased growth in the next 7 years. Douglas-fir had similar growth on burned and unburned plots. Growth was not reduced by low levels of crown scorch or cambial injury. Stand basal area growth was less on burned plots due to high fire-caused mortality.

Fuzzy Logic Merger of Spectral and Ecological Information for Improved Montane Forest Mapping

Abstract Environmental data are often utilized to guide interpretation of spectral information based on context, however, these are also important in deriving vegetation maps themselves, especially where ecological information can be mapped spatially. A vegetation classification procedure is presented which combines a classification of spectral data from Landsat‐5 Thematic Mapper (TM) and environmental data based on topography and fire history. These data were combined utilizing fuzzy logic where assignment of each pixel to a single vegetation category was derived comparing the partial membership of each vegetation category within spectral and environmental classes. Partial membership was assigned from canopy cover for forest types measured from field sampling. Initial classification of spectral and ecological data produced map accuracies of less than 50% due to overlap between spectrally similar vegetation and limited spatial precision for predicting local vegetation types solely from the ecological information. Combination of environmental data through fuzzy logic increased overall mapping accuracy (70%) in coniferous forest communities of northwestern Montana, USA.

Wildland fire in ecosystems: effects of fire on cultural resources and archaeology

This state-of-knowledge review provides a synthesis of the effects of fire on cultural resources, which can be used by fire managers, cultural resource (CR) specialists, and archaeologists to more effectively manage wildland vegetation, fuels, and fire. The goal of the volume is twofold: (1) to provide cultural resource/archaeological professionals and policy makers with a primer on fuels, fire behavior, and fire effects to enable them to work more effectively with the fire management community to protect resources during fuels treatment and restoration projects and wildfire suppression activities; and (2) to provide fire and land management professionals and policy makers with a greater understanding of the value of cultural resource protection and the methods available to evaluate and mitigate risks to CR. The synthesis provides a conceptual fire effects framework for planning, managing, and modeling fire effects (chapter1) and a primer on fire and fuel processes and fire effects prediction modeling (chapter 2). A synthesis of the effects of fire on various cultural resource materials is provided for ceramics (chapter 3), lithics (chapter 4), rock art (chapter 5), historic-period artifacts/materials (chapter 6), and below-ground features (chapter 7). Chapter 8 discusses the importance of cultural landscapes to indigenous peoples and emphasizes the need to actively involve native people in the development of collaborative management plans. The use and practical implications of this synthesis are the subject of the final chapter (chapter 9).