Treesearch

The initial phase of the research that addressed correlation between annual forest disturbance maps produced from LANDSAT images and water quality and flow data indicate that forest disturbances in conjunction with intense atmospheric precipitation commonly trigger fluxes of several chemical constituents, such as nitrogen, phosphorus carbon. These fluxes appear to be correlated with intense soil erosion. While concentration on N, P and dissolved C do not significantly fluctuate, their total fluxes vary by five to twenty times when flow volumes increase by on order of magnitude during peak...

For most simulation modeling efforts, the goal of model developers is to produce simulations that are the best representations of realism as possible. Achieving this goal commonly requires a considerable amount of data to set the initial parameters, followed by validation and model improvement – both of which require even more data. The Forest Vegetation Simulator (FVS) is a widely-used, distance-independent forest growth simulator that can be used to model a wide variety of forest conditions and silvicultural treatments. Extensions to FVS include modules for simulating fire effects and...

The use of fire as a land management tool is well recognized for its ecological benefits in many natural systems. To continue to use fire while complying with air quality regulations, land managers are often tasked with modeling emissions from fire during the planning process. To populate such models, the Landscape Fire and Resource Management Planning Tools (LANDFIRE) program has developed raster layers representing vegetation and fuels throughout the United States; however, there are limited studies available comparing LANDFIRE spatially distributed fuel loading data with measured fuel...

FIESTA (Forest Inventory ESTimation for Analysis) is a user-friendly R package that was originally developed to support the production of estimates consistent with current tools available for the Forest Inventory and Analysis (FIA) National Program, such as FIDO (Forest Inventory Data Online) and EVALIDator. FIESTA provides an alternative data retrieval and reporting tool that is functional within the R environment, allowing customized applications and compatibility with other R-based analyses. Over the last few years, the tool has expanded to include new modules that accommodate nonrespons...

Raster modeling is an integral component of spatial analysis. However, conventional raster modeling techniques can require a substantial amount of processing time and storage space, often limiting the types of analyses that can be performed. To address this issue, we have developed Function Modeling. Function Modeling is a new modeling framework that streamlines the raster modeling process by utilizing delayed reading methods. Using this approach, we have successfully characterized the impacts of fuel treatments on soil erosion, estimated basal area, trees, and tons of above ground biomass...

Trout, salmon, grayling and whitefishes (Salmonidae) are among the most ecologically and economically important fishes. They also are among the most vulnerable to global warming, and increasing drought, floods, and wildfires. In North America, salmonids occur from central Mexico northward along coastal regions and mountainous interiors to the Arctic Plains. A variety of existing stressors have reduced population sizes and extent and fragmented habitats, making salmonid populations increasingly vulnerable to climate-driven disturbances. This contribution explores specific threats posed by...

In the western US, Greater Sage-Grouse (Centrocercus urophasianus Bonaparte [Phasianidae]) have become an indicator species of the overall health of the sagebrush (Artemisia L. [Asteraceae]) dominated communities that support a rich diversity of flora and fauna. This species has an integral association with sagebrush, its understory forbs and grasses, and the invertebrate community dependent on that flora. Adult birds and their growing chicks consume a wide variety of understory species, and the invertebrates that develop on this flora are an important source of protein, especially for...

The prediction of invasion patterns may require an understanding of intraspecific differentiation in invasive species and its interaction with climate change. We compare Japanese honeysuckle (Lonicera japonica) plants from the core (100-150 yr old) and northern margin (< 65 yr old) of their North American invaded range to determine whether evolution during invasion increases the probability of future expansion.

The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume, require a more in-depth understanding of the FIA compilation system, such as how equations are selected based on species and plot location. For other computed variables, their derivation and meaning might not be clear to many...

Mapping the number, size, and species of trees in forests across the western United States has utility for a number of research endeavors, ranging from estimation of terrestrial carbon resources to tree mortality following wildfires. For landscape fire and forest simulations that use the Forest Vegetation Simulator (FVS), a tree-level dataset, or “tree list”, is a necessity. FVS is widely used at the stand level for simulating fire effects on tree mortality, carbon, and biomass, but uses at the landscape level are limited by availability of forest inventory data for large contiguous areas....