Treesearch

Interacting regeneration stressors create challenges for policy makers and managers who are tasked with making decisions for restoring forest following major disturbances, such as harvest or catastrophic mortality. Concern over an aging forest, dwindling young forest habitat, and restoration of native forests in the midwest and northeast United States has resulted in the development of the regeneration indicator (RI), a new ecological health indicator derived from 25 years of measuring advance regeneration in Pennsylvania. The RI protocols were added to the Northern Research Station (NRS),...

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...

Variability in historic fire regimes in eastern North America resulted in an array of oak savannahs, woodlands and forests that were dominant vegetation types throughout the region. In the past century, once abundant savannahs and woodlands have become scarce due to conversion to agriculture, or development of forest structure in the absence of fire. In addition, the future dominance of oak forests is uncertain due to chronic low regeneration potential of oak across the region and insufficient overstory recruitment. Restoration of oak savannahs and woodlands, and sustaining oak forests are...

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...

Many alien insect species currently impacting forested ecosystems in North America first appeared in urban forests. Unfortunately, despite serving as critical gateways for the human-mediated spread of these and other forest pests, urban forests remain less well documented than their “natural” forest counterparts. While Forest Inventory and Analysis (FIA) data provide good information about the composition of natural forests, only a small percentage of the more than 26,000 communities in the US and Canada have completed any sort of urban forest inventory, and these inventories have commonly...

Using empirical data from FIA, we modeled invasion richness and invasion prevalence as functions of 22 factors reflective of propagule pressure and/or habitat invasibility across the continental US. Our statistical models suggest that both propagule pressure and habitat invasibility contribute to macroscale patterns of forest plant invasions. Our investigation provides insight into sub-continental invasion patterns and processes, confirming the utility of accounting for multiple invasion measures and sub-regional heterogeneity.

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...

Biodiversity is expected to convey numerous functional benefits to forested ecosystems, including increased productivity and resilience. When assessing biodiversity, however, statistics that account for evolutionary relationships among species may be more ecologically meaningful than traditional measures such as species richness. In three broad-scale studies, we applied evolutionary diversity metrics to assess the relationship between biodiversity and forest function across broad U.S. regions, using Forest Inventory and Analysis (FIA) data. In one study, we assessed trends in live abovegrou...

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...

Small area estimation (SAE) techniques have been successfully applied in forest inventories to provide reliable estimates for domains where the sample size is small (i.e. small areas). Previous studies have explored the use of either Area Level or Unit Level Empirical Best Linear Unbiased Predictors (EBLUPs) in a univariate framework, modeling each variable of interest at a time, and not considering their potential correlation. Yet most forest inventory variables such as basal area (G) and volume (V) are strongly correlated. In this situation, EBLUPs for multivariate responses can improve...