DOI: 10.48443/e3qn-xw47
title: Woody plant vegetation structure (DP1.10098.001)
title: RELEASE-2021

description: This data product contains the quality-controlled, native sampling resolution data from in-situ measurements of live and standing dead woody individuals and shrub groups, from all terrestrial NEON sites with qualifying woody vegetation. The exact measurements collected per individual depend on growth form, and these measurements are focused on enabling biomass and productivity estimation, estimation of shrub volume and biomass, and calibration / validation of multiple NEON airborne remote-sensing data products. In general, comparatively large individuals that are visible to remote-sensing instruments are mapped, tagged and measured, and other smaller individuals are tagged and measured but not mapped. Smaller individuals may be subsampled according to a nested subplot approach in order to standardize the per plot sampling effort. Structure and mapping data are reported per individual per plot; sampling metadata, such as per growth form sampling area, are reported per plot. For additional details, see the user guide, protocols, and science design listed in the Documentation section in this data product's details webpage.

Latency:
The expected time from data and/or sample collection in the field to data publication is as follows, for each of the data tables (in days) in the downloaded data package. See the Data Product User Guide for more information.

vst_apparentindividual:  90

vst_mappingandtagging:  90

vst_perplotperyear:  300

vst_shrubgroup:  90
description: Woody Plant Vegetation Structure data are collected from distributed and tower plots. Each distributed plot is sampled in a given bout if at least one tree with Diameter at Breast Height (DBH) ≥ 10 cm is present; if trees with DBH ≥ 10 cm are absent, distributed plots are sampled if smaller woody individuals comprise ≥ 10% aerial cover of the plot. Tower plots are sampled if at least one tree with DBH ≥ 10 cm is present in ≥ 10% of tower plots, or if smaller woody individuals comprise ≥ 10% of aerial cover averaged across all tower plots. Within both distributed and tower plots, all individuals with DBH ≥ 10 cm are mapped and measured throughout the plot sampling area. Individuals with DBH < 10 cm are mapped if a) individuals with DBH ≥ 10 cm are absent from the plot, and b) they are visible to airborne remote-sensing instruments. If stem density thresholds are met, individuals with DBH < 10 cm may be measured within nested subplots in order to standardize the sampling effort across plots.

At all sites at which qualifying woody vegetation is present, distributed plots are sampled every 5 years. At most sites with qualifying woody vegetation, a spatially-balanced subset of n=5 tower plots are sampled annually, and the full complement of tower plots is sampled every 5 years. At slow-growth-increment sites (RMNP, YELL, NIWO, WREF, SJER, SOAP, TEAK, BONA, DEJU, HEAL), dendrometer bands are measured annually on a subset of individuals within tower plots. At desert sites with sensitive vegetation and soils (i.e., MOAB, JORN, SRER, ONAQ), there is no annual tower plot measurement and the full complement of tower plots is measured every 5 years only.

At all sites, distributed plot sampling and ‘full’ tower plot sampling is scheduled in a staggered manner such that sites generate data either from all distributed plots or all tower plots every 2-3 years. Sites that do not have qualifying woody vegetation are surveyed every 5 years to determine whether ingrowth of qualifying woody vegetation has occurred.

At sites with seasonal senescence, the onset of sampling in a given year is triggered by senescence of canopy or understory individuals. Sampling must be completed before growth begins the following season and within 4 months of sampling onset. At sites with no distinct season, sampling begins within ± 2 weeks of the same date, and must be completed within 60 days of sampling onset. See NEON.DOC.000987 for more details.