Treesearch

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...

Plot mapping is one of the innovations that were implemented when FIA moved to the annual forest inventory system. Mapped plots can improve the precision of estimates if the mapped conditions are carefully chosen and used judiciously. However, after plots are remeasured multiple times, it can be difficult to properly track changes in conditions and incorporate this into the analysis. Early discussions about plot mapping considered 2 mapping options: 1) full mapping and 2) fuzzed mapping. Full mapping is what FIA adopted. Fuzzed mapping (fuzzing) was felt to provide less precision, since it...

Understanding forest ecosystems is paramount for their sustainable management and for the livelihoods and ecosystem services which depend on them. However, the complexity and diversity of these systems poses a challenge to interpreting data patterns. The availability and accessibility of data and tools often determine the method selected for forest assessment. Capacity building is fundamental to ensure that sampling methods, data analysis and use of tools are efficiently and sustainably appropriated. FAO has trained people from over 30 countries to develop tools and databases to improve...

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....

Imputation models were developed and tested to estimate tree regeneration on Forest Service land in Oregon and Washington. The models were based on Forest Inventory and Analysis and Pacific Northwest Regional NFS Monitoring data. The data was processed into sets of tables containing estimates of regeneration by broad plant associations and spanning a large variety in forest cover conditions. The output tables were organized to facilitate their use within variants of FVS commonly used in the Pacific Northwest region. The methods were implemented in a highly reproducible fashion to ensure...

The effects of subsample design and imputation of total height (ht) and live crown ratio (cr) on the accuracy of stand-level estimates of component and total aboveground biomass are not well investigated in the current body of literature. To assess this gap in research, this study uses a data set of 3,454 Douglas-fir trees obtained from 102 stands in southwestern Oregon to simulate different combinations of subsample designs and imputation methods. The predictive ability of the regional ht and cr imputation methods on estimates of component and total aboveground biomass for a range of...

In the summer of 2014 the US Forest Service’s Forest Inventory and Analysis (FIA) Program of the Pacific Northwest (PNW) Research Station in conjunction with NASA Goddard carried out a pilot inventory of the forests of interior Alaska. This inventory was conducted on the State of Alaska’s Tanana Valley State Forest and on the Tetlin National Wildlife Refuge. As part of the field protocols that were implemented, field crews measured Down Woody Material (DWM), sampled soils and collected tree cores. The DWM protocols were based on standard FIA protocols. The soil sampling included a modified...

Vegetation profile data were collected as part of a forest inventory project in the Tanana Valley in interior Alaska, providing a means of characterizing the forest vegetation. The black spruce forest type was most common, followed by Alaska paper birch, and white spruce, quaking aspen, and balsam poplar. For individual tree species, black spruce was recorded on 68 percent of all plots, birch was recorded on 67 percent and white spruce on 58 percent. The distribution of growth habits in horizontal layers varied by forest type. There was a higher percentage tree cover in hardwood forest...

A fundamental goal of the forest inventory in interior Alaska is to accurately estimate carbon pools in a way that sheds light on the feedbacks between forests and climate. In boreal forests, moss and lichen mats often serve as the interface between soils and the atmosphere, therefore characterizing the biomass and composition of mats is essential for understanding how forest carbon exchange might interact with shifting climatic regimes. Previous estimation approaches did not permit volumetric estimates of moss mats and were based on inconsistent definitions distinguishing between soil,...