Treesearch

Models of forest succession provide an appealing conceptual framework for understanding forest dynamics, but uncertainty in the degree to which patterns are regionally consistent might limit the application of successional theory in forest management. Remeasurements of forest inventory networks provide an opportunity to assess this consistency, improving our understanding of forest dynamics through succession at regional scales. In this study, we examined the responses of proportional Pseudotsuga menziesii biomass change to successional status, relative abundance, resource availability,...

The air in California’s forests spans a broad range of purity, from virtually no locally generated pollutants to highly elevated levels of pollutants in forests downwind of urban and agricultural source areas. Ten-year remeasurement data from Forest Inventory and Analysis (FIA) plots in California were used in combination with modelled atmospheric nitrogen (N) deposition to evaluate tree diameter growth and mortality responses across the state. After controlling for tree size, site productivity, climate attributes, stand density, and competition experienced by each tallied tree, we found...

How vulnerable are US forest to a changing climate? We answer this question using Landsat time series data and a unique interpretation approach, TimeSync, a plot-based Landsat visualization and data collection tool. Original analyses were based on a stratified two-stage cluster sample design that included interpretation of 3858 forested plots. From these data, we derived annual plot-based estimates (with uncertainties) of rates of forest decline from 1985-2012. Noted was a dramatic national-level increase in rates from the mid-90s (<1% of total forest per year) to 2000 (nearly 3% per...

Estimates of forest soil organic carbon stocks across the US are currently developed from expert opinion in STATSGO/SSURGO and linked to forest type. The results are reported to the US EPA as the official United States submission to the UN Framework Convention on Climate Change. Beginning in 2015, however, estimates of soil organic carbon (SOC) stocks will be based on SOC data from soil cores collected in the field (0-10 and 10-20 cm depth). In addition, the Intergovernmental Panel on Climate Change (IPCC) Good Practice Guidance suggests these estimates extend to at least 30 cm for all...

The Pacific Northwest Research Station’s Forest Inventory and Analysis Unit began remeasurement of permanently located FIA plots under the annualized design in 2011. With remeasurement has come the need to implement the national FIA system for compiling estimates of forest growth, removals, and mortality. The national system requires regional diameter-growth models to estimate diameters on trees in situations where the initial or terminal diameter is not known at the beginning or end of a measurement interval. Examples of such trees are those classified as alive at the beginning of the...

Changes in the national Forest Inventory and Analysis (FIA) processing system required the Southern Research Station’s FIA unit to create a diameter growth model to estimate the growth of trees that could not be measured at both ends of a measurement interval. Examples of such trees are trees that have died or been harvested, and trees that grow over the minimum diameter threshold. I used a form of the Chapman-Richards function to model the growth. A function containing crown ratio, condition basal area, amount of basal area in larger trees, latitude, longitude, elevation, site class, tree...

Dead wood (DW) plays a critical role not only in maintaining biodiversity but also in stocking carbon under UNFCCC. From the 5th national forest inventory (NFI5; 2006-2010) in South Korea, field data relevant to the DW including standing and downed dead trees by four decay class, etc. were collected. Based on the NFI5 data, the average volume of DW over the country is estimated to be 12.3m3/ha of which the total carbon stock accounts for 10.9 Tg C. Recently, NFI6 (2011-2015) has been implemented into monitoring and assessing forest resources including DW over time. We are to analyze...

The Forest Carbon Management Framework (ForCaMF) integrates Forest Inventory and Analysis (FIA) plot inventory data, disturbance histories, and carbon response trajectories to develop estimates of disturbance and management effects on carbon pools for the National Forest System. All appropriate FIA inventory plots are simulated using the Forest Vegetation Simulator (FVS) growth model to develop the carbon response trajectories for undisturbed, managed, and disturbance from fire, pests, and in some regions wind. The challenges presented by the number of plots, number of FVS variants,...

Forest ecosystems are an important component of the global carbon (C) cycle. Recent research has indicated that large trees in general, and old-growth forests in particular, sequester substantial amounts of C annually. C sequestration rates are thought to peak and decline with stand age but the timing and controls are not well-understood. The objectives of this study were to determine how the balance of tree growth, mortality, and dead wood decay vary by plant community type, site productivity, and stand age. We compiled remeasured tree and dead wood estimates from 8,767 inventory plots on...

Estimates of carbon stocks and stock changes in the U.S. Department of Agriculture Forest Service’s Forest Inventory and Analysis (FIA) Program are reported as the official United States submission to the UN Framework Convention on Climate Change. Soil, as a critical component of the forest carbon stocks, has been sampled in about 10-year intervals in FIA with the re-measurement underway. However, the magnitude of detectable change in soil organic carbon (SOC) with the current sampling scheme is unknown. We aim to identify SOC variability and to best determine minimum detectable changes in...