Treesearch

This study examined the utility of dense time series of Landsat imagery for small area estimation and mapping of change in forest conditions over time. The study area was a region in north central Wisconsin for which Landsat 7 ETM+ imagery and field measurements from the Forest Inventory and Analysis program are available for the decade of 2003 to 2012. For the periods 2003-2007 and 2008-2012, the monthly imagery was processed using harmonic analysis in order to capture seasonal trends in reflectance across spectral bands. A nonparametric modeling approach was used with predictor variables...

As part of the U.S. Forest Service (USFS), National Forest System (NFS) comprehensive plan for carbon monitoring, a detailed temporal mapping of forest disturbances across all National Forests in the United States has been conducted. A long-term annual time series of data layers that show the timing, extent, type, and magnitude of disturbance beginning in 1990 and ending in 2011 is available for all the USFS Regions. Our mapping approach starts with an automated initial detection of annual disturbances using imagery captured within the growing season from the Landsat archive. Through a...

We present a new R package called ShapeSelectForest recently posted to the Comprehensive R Archival Network. The package was developed to fit nonparametric shape-restricted regression splines to time series of Landsat imagery for the purpose of modeling, mapping, and monitoring annual forest disturbance dynamics over nearly three decades. For each pixel and spectral band or index of choice in temporal Landsat data, the package delivers an optimally smoothed rendition of the trajectory constrained to behave in an ecologically sensible manner, assuming one of seven possible “shapes”. It also...

Over the past several years, three sets of new temporal remote sensing data have become available improving FIA’s ability to detect, characterize and forecast land cover changes. First, historic Landsat data has been processed for the conterminous US to provide disturbance history, agents of change, and fitted spectral trajectories annually over the last 30+ years at 30 m resolution. Second, the collection of TimeSync data is becoming more widespread and allows image interpreters to capture three decades of forest disturbance and recovery on FIA plots in a consistent and repeatable...

Restoration in the Great Basin is typically a large-scale enterprise, with aerial, drill, and broadcast seeding of perennial species common after wildfires. Arid conditions and invasive plants are significant barriers to overcome, but relatively simple changes to seeds used for restoration may improve success. Here we summarize: 1) the composition of seed mixes used in recent postfire seedings in Nevada, 2) traits that were valued when cultivars and other native seed materials were named and released, and 3) traits that have been demonstrated to increase native perennial grass performance...

Conservation of avian species requires understanding their nesting habitat requirements. We compared 3 aspects of habitat at nest sites (topographic characteristics of nest sites, nest placement within nest sites, and canopy stratification within nest sites) of 2 related species of ground-nesting warblers (Red-faced Warblers, Cardellina rubrifrons, n = 17 nests; Painted Redstarts, Myioborus pictus, n = 22 nests) in the Sky Island mountain ranges of southeastern Arizona. These species nested in several forest and woodland cover types that occurred along an elevational gradient. Red-faced...

The Pinaleno Mountains in southeastern Arizona represent a Madrean sky island ecosystem that contains the southernmost expanse of spruce-fir forest type in North America. This ecosystem is also the last remaining habitat for the Mt. Graham red squirrel (Tamiasciurus hudsonicus grahamenis), a federally listed endangered species. Due to a general shift in species composition and forest structure of spruce-fir type forests across the Southwest, the ecosystem is being threatened by large high-severity fires, insect infestation, and a general loss of biodiversity. These risk factors have led...

The abundance of temporally and spatially consistent Forest Inventory and Analysis data facilitates hierarchical/multilevel analysis to investigate factors affecting tree growth, scaling from plot-level to continental scales. Herein we use FIA tree and soil inventories in conjunction with various spatial climate and soils data to estimate species-specific responses of tree growth to nitrogen (N) deposition across the contiguous United States. Plot-level analyses have shown that N deposition affects tree growth but not uniformly. Increases in bio-available N can stimulate tree growth rates...

Querying the Forest Inventory and Analysis Database (FIADB) for growth, removals, and mortality (GRM) estimates can certainly be a conundrum. Providing the flexibility necessary to produce a wide array of GRM estimates has the unfortunate side effect of added complexity. This presentation seeks to answer some recurring questions related to GRM and how our new system can be leveraged to meet our needs. Questions addressed include: • What is the difference between the accounting and other methods of summarizing GRM estimates? • Why do GRM estimates for an eastern evaluation include plots...

Extreme weather events play a role in shaping the composition and structure of forests. Responding to and mitigating a storm event in a forested environment requires information about the location and severity of tree damage. However, this information can be difficult to obtain immediately following an event. Post-storm assessments using regularly collected forest information from the Forest Inventory and Analysis (FIA) program of the USDA Forest Service can help inform response to future storm events. We analyzed data from the FIA program for an area along the Atlantic Coast directly in...