Treesearch

Increasingly detailed records of long-term fire regime characteristics are needed to test ecological concepts and inform natural resource management and policymaking. We reconstructed and analyzed twelve 350+ yr-long fire scar records developed from 2612 tree-ring dated fire scars on 432 living and dead pine (Pinus pungens, Pinus rigida, Pinus resinosa, Pinus echinata) trees from across central Pennsylvania. We used multiple spatial and time series analysis methods to quantify fire regime characteristics (frequency, seasonality, percentages of trees scarred, extent) and fire–climate–human...

This resource update provides an overview of forest resources in Minnesota based on an inventory conducted by the USDA Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station in cooperation with the Minnesota Department of Natural Resources. Estimates are based on field data collected from 2013–2017 with comparisons made to field data collected in 2008–2012. The 2013–2017 sample data was collected from 6,290 field measured plots on forest land, with 20 percent collected per year. Data used in this publication were accessed from the FIA database in March...

Understanding how urban forests developed their current patterns of tree canopy cover, species composition, and diversity requires an appreciation of historical legacy effects. However, analyses of current urban forest characteristics are often limited to contemporary socioeconomic factors, overlooking the role of history. The institutions, human communities, and biophysical conditions of cities change over time, creating layers of legacies on the landscape, shifting urban forests through complex interactive processes and feedbacks. Urban green spaces and planted trees can persist long...

We examined how different landscape areas in a catchment containing a northern ombrotrophic peatland and upland mineral soils responded to dramatic decreases in atmospheric deposition of lead (Pb). Pb concentrations in the outflow stream from the peatland measured from 2009−2015 indicated continued mobilization and export of Pb derived from historic inputs to the bog. In contrast, Pb concentrations in surface peat and runoff from upland mineral soils have declined in response to reductions in atmospheric deposition. Relative to the early 1980s, Pb concentrations in the streamflow decreased...

The design of a precipitation monitoring network must balance the demand for accurate estimates with the resources needed to build and maintain the network. If there are changes in the objectives of the monitoring or the availability of resources, network designs should be adjusted. At the Hubbard Brook Experimental Forest in New Hampshire, USA, precipitation has been monitored with a network established in 1955 that has grown to 23 gauges distributed across nine small catchments. This high sampling intensity allowed us to simulate reduced sampling schemes and thereby evaluate the effect...

This resource update provides an overview of forest resources in Michigan based on inventories conducted by the USDA Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. The annual inventory started in 1999. For the 2017 inventory, estimates for current variables such as area, volume, and biomass are based on 6,647 plot samples collected from 2011 to 2017. Change variables, such as net growth, removals, and mortality, are based on 6,050 samples...

When standing dead trees (snags) fall, they have major impacts on forest ecosystems. Snag fall can redistribute wildlife habitat and impact public safety, while governing important carbon (C) cycle consequences of tree mortality because ground contact accelerates C emissions during deadwood decay. Managing the consequences of altered snag dynamics in changing forests requires predicting when snags fall as wood decay erodes mechanical resistance to breaking forces. Previous studies have pointed to common predictors, such as stem size, degree of decay and species identity, but few have...

Background: Knowledge of the different kinds of tree communities that currently exist can provide a baseline for assessing the ecological attributes of forests and monitoring future changes. Forest inventory data can facilitate the development of this baseline knowledge across broad extents, but they first must be classified into forest community types. Here, we compared three alternative classifications across the United States using data from over 117,000 U.S. Department of Agriculture Forest Service Forest Inventory and Analysis (FIA) plots.Methods: Each plot had three forest community...

Demographic processes (fecundity, dispersal, colonization, growth, and mortality) and their interactions with environmental changes are notwell represented in current climate-distribution models (e.g., niche and biophysical process models) and constitute a large uncertainty in projections of future tree species distribution shifts.We investigate how species biological traits and environmental heterogeneity affect species distribution shifts. We used a species-specific, spatially explicit forest dynamic model LANDIS PRO, which incorporates site-scale tree species demography and competition,...