Perhaps the most important element of a monitoring program is where the treatments and subsequent
monitoring project will be implemented. A detailed geographical description of the area to be sampled is an absolute necessity because it will also provide context for design descriptions. In statistical terms
this description provides the scope of the treatments and, in most monitoring programs, the scope of
inferences made by the statistical tests. Boundaries of the entire sample area should be explicitly stated and diagrammed on an appropriate map. In most cases, large scale maps (such as National Forest maps) will not provide the detail needed for a fire monitoring effort. Maps with a scale less than 1:30,000 will do a better job of accurately delineating the project area.
The entire sampling area must be spatially divided into sampling stratifications that match the sampling objective. Most resource managers delineate areas of homogeneous vegetation (stands), but fire monitoring can be stratified by other classifications such as aspect, slope, fuel condition, or land ownership. FIREMON presents procedures for mapping areas of similar fire severity from satellite imagery (see Landscape Assessment section), and the manager can also use severity as a stratifying factor.
As you define your strata be sure to match the mapping criteria with your sampling objectives. For example, if ponderosa pine restoration is a primary objective, then be sure the strata mapping guidelines delineate various successional stages of ponderosa pine communities. The sampling design can incorporate more than one stratification factor. For instance, a possible design might be to install FIREMON plots in all old-growth ponderosa pine stands that have slopes less than 50 percent and are on National Forest lands.
Figure ISS-2 shows three ecological characteristics mapped on a sample landscape: A) three levels of tree density, B) two levels of dead and down fuel load, and C) a corridor of exotic weed invasion along
the roads. The levels would be determined by the FIREMON architect based on project objectives. In D, characteristics A, B, and C are combined to identify nine sampling strata divided into 17 polygons. One stratum has low tree density and low fuel without exotic weeds, another has low tree density and low fuel with exotic weeds, another has moderate tree density and low fuel without exotic weeds, and so on. Potentially there could have been 12 strata in this example (3 x 2 x 2 = 12) but not all of the combinations occurred. Note how quickly adding ecological characteristics and levels increases the potential number of sampling polygons, which in turn increases the complexity of the monitoring project. This example landscape will be used for demonstration throughout the ISS.
The mapping of sampling entities across the landscape is greatly dependent on the type of fire: prescribed burns or wildfires (postevent monitoring projects versus complete monitoring projects). The difference is that for wildfires and wildland fire use, fire effects monitoring plots are installed after the fire, whereas prescribed fire monitoring plots are measured both before and after the burn. Most wildland fire use burns (previously called prescribed natural fires) fall into the postevent category because of the absence of preburn plots. In these cases, sample stands must be identified after the wildfires using remotely sensed images (aerial photos or satellite imagery) taken before the fire if fire effects measurements are to be summarized by vegetation type. If fire severity stratification is necessary the Landscape Assessment methodology can be used.
The mapping effort, and its integration with FIREMON sampling efforts, can be made much easier if the mapping and analysis are done within a Geographical Information System (GIS). A GIS allows complex queries on landscape and stand attributes that make design and subsequent implementation of a FIREMON sampling strategy efficient. A GIS can produce maps of the sample area for reference and navigation, and the sampled FIREMON field data can be linked to the GIS for many other applications (landscape pattern analysis, satellite imagery mapping).
Two statistics must be computed once the sample area has been mapped and the landscape divided into polygons. First, compute the total treatment area of the study site(s). Exclude all areas that will not be sampled (talus slopes, lakes, glaciers) from the estimate. Then, compute the number of polygons or stands within the area to be sampled. These statistics will be used to determine the resources needed to accomplish the sampling.
The sampling environment, like the project goal and objectives, provides the spatial and logistical sideboards for project planning. There are four attributes about the sampling area that must be known before sampling design can continue: 1) size of area, 2) topographic complexity, 3) transportation network, and 4) ecological characteristics. The size of the sampling project is often dictated by the boundary of the burn, and burn boundaries are notoriously coarse, so it is important that a precisely Figure ISS-2—Overlay maps of strata defined by the stratifying factors in your monitoring project to identify
the different polygons on the landscape. Once a sampling design has been determined, the polygons will be sampled with FIREMON plots. In this figure the strata of A) tree density, B) fuel load, and C) exotic weed invasion are overlaid to identify the sample polygons in D. Each shade and/or patten combination represents a specific sampling strata. There are 17 polygons grouped into 9 sampling strata.
developed burn map is provided for monitoring. Topography will dictate many aspects of the sampling effort. Steep, dissected landscapes will be difficult and dangerous to navigate, so the sampling project should be designed to accommodate or avoid these troublesome conditions. The network of roads, trails, and navigable terrain will provide the means of transporting crews to sampling areas. Remote areas with only trail access will require another level of planning because crews will probably need backcountry supplies along with the already extensive sampling gear, and this may require packstock support (mule and horse packing). Last, the ecological characteristics of the sample area will dictate the sampling design and methods. Forested environments will probably require time-intensive individual tree surveys, while rangeland types can be sampled using standard vegetation surveys. Areas with thick vegetation or high fuel loadings will be difficult to traverse. And areas with abundant threatened and endangered species will require a high resolution sampling design to properly evaluate fire’s impact in small but highly valuable habitats.