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  • Knowledge of the optical properties of the components of the forest canopy is important to the understanding of how plants interact with their environment and how this information may be used to determine vegetation characteristics using remote sensing. During the summers of 1983 and 1984, samples of the major components of the boreal forest canopy (needles, leaves, branches, moss, litter) were collected in the Superior National Forest (SNF) of Minnesota and sent to the Johnson Space Center (JSC). At JSC, the spectral reflectance and transmittance characteristics of the samples were determined for wavelengths between .35 and 2.1 micrometers using the Cary-14 radiometer. This report presents plots of these data as well as averages to the Thematic Mapper Simulator (TMS) bands. There were two main thrusts to the SNF optical properties study. The first was to collect the optical properties of many of the components of the boreal forest canopy. The second goal of the study was to investigate the variability of optical properties within a species. The results of these studies allow a comparison of the optical properties of a variety of different species and a measure of the variability within species. These data provide basic information necessary to model canopy reflectance patterns. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]SNF_LEAFCARY ]

  • The Total Leaf Tissue Water Potential Data Set was collected during the summer months of 1988 and 1989. The objective of this study was to determine the influence of plant water status on surface reflectance factors. Measurements were made at six stations on Indian grass, switch grass, Big bluestem, little bluestem, and tall dropseed. Leaf water potential measurements were usually made on the same leaf that optical measurements were made and on leaves of surrounding plants. Measurements were made on the most recently expanded leaf of the selected plant unless specified. Measurements were also made of older green and yellow leaves on a plant. Leaf water potential measurements can be linked with the leaf optical properties data if the plant number in both sets of data are known. Plant water potential values measured just before dawn will provide the highest plant water potential (smallest negative value) during the day and also provides a reasonable estimate of the soil water potential. It is hypothesized that as the leaf water potential decreases (large negative value) that there may be some change in the internal structure of the leaf that would be detectable in one or more of the Nebraska Multiband Leaf Radiometer (NMLR - instrument used during leaf optical measurements) wavebands. It is also hypothesized that the amounts of water in a leaf will be lowest at low water potential and that this might also be detectable with the NMLR especially in the mid-IR wavebands. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]FIFE_LEAF_H2O ]

  • Height, crown width, DBH, and height-to-crown distance collected using variable-radius plot sampling with a steel tape and a hand held compass to locate points along a transect. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]OTTER_TIMBER ]

  • The FIFE Root Biomass data were collected from 16 locations within the FIFE study area during the 1987 growing season. They provide a measure of the below-ground biomass for the study area. Biomass reported as grams per square m assumes that the depth of the core samples is sufficient to include all root biomass under the surface to an infinite depth. Prairie vegetation does possess roots deeper than the 20 cm coring, however, the fraction of total root biomass below 20 cm is minuscule and safely ignored in a study of biomass. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]FIFE_ROOT_BIO ]

  • The BOREAS TE-12 team collected PAR data sets in support of its efforts to characterize and interpret information on shoot geometry, leaf optical properties, leaf water potential, and leaf gas exchange. The data were collected at the SSA-OBS site from 04-Jul-1996 to 25-Jul-1996. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]BOREAS_TE12PARC ]

  • Net primary production of a saline grassland was determined at the Montecillo study site belonging to Colegio de Postgraduados, Chapingo, near Mexico City, from 1984 to 1994. Monthly dynamics of live biomass and dead matter were monitored, above and below ground, together with monthly litter bag estimates of decomposition rates above and below ground. The method for calculating net primary production accounted for simultaneous growth and death, and carbon flows to all trophic levels. Work was carried out under the UNEP (United Nations Environment Programme) Project on "Primary productivity of grass ecosystems of the tropics" and continued under subsequent UNEP and UK-ODA (Overseas Development Administration) sponsored international projects. Climate data for this site are also available: see Any Other Relevant Information in section 11 of this document. More information on the entire Net Primary Production Project can be found at the NPP homepage. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]NPP_MNT ]

  • The BOREAS TE-20 team collected several data sets for use in developing and testing models of forest ecosystem dynamics. This data set contains measurements of site characteristics conducted in the SSA from 18-Jul-1994 to 30-Jul-1994. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]BOREAS_TE20SITE ]

  • The RSS-04 team collected several data sets related to leaf, plant, and stand physical, optical, and chemical properties. This data set contains leaf area indices and FPAR measurements which were taken at the three conifer sites in the BOREAS SSA during August 1993 and at the jack pine tower flux and a subset of auxiliary sites during July and August 1994. The measurements were made with LAI-2000 and Ceptometer instruments. The measurements were taken for the purpose of model parameterization and to test empirical relationships that were hypothesized between biophysical parameters and remotely sensed data. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]BOREAS_R04LAIFD ]

  • In an effort to properly document the sites and areas where data were collected, personnel of the BOReal Ecosystem-Atmosphere Study (BOREAS) Information System (BORIS) obtained and compiled geographic coordinate and other site information from several sources throughout the experiment period. The final set of information is organized into two data sets that provide geographic coordinate and site characteristic information for single sites and corner coordinates for standard geographic areas. The data are stored in two text files as American Standard Code for Information Interchange (ASCII) characters. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]BOREAS_GEOCOORD ]

  • Approximately 1000 published estimates of leaf area index (LAI) from nearly 400 unique field sites, covering the period 1932-2000, have been compiled into a single data set. LAI is a key parameter for global and regional models of biosphere/atmosphere exchange of carbon dioxide, water vapor, etc. This data set provides a benchmark of typical values and ranges of LAI for a variety of biomes and land cover types, in support of model development and validation of satellite-derived remote sensing estimates of LAI and other vegetation parameters. The LAI data are linked to a bibliography of over 300 original-source references. These historical LAI data are mostly from natural and semi-natural (managed) ecosystems, although some agricultural estimates are also included. Caution is advised in using these data; they were collected using a wide range of methodologies and assumptions and may not be comparable among sites. Some attempts have been made to detect and flag the outliers in this data set, according to different biome/land cover classes. Needleleaf (coniferous) forests are by far the most commonly measured biome/land cover types in this compilation, with 22% of the measurements from temperate evergreen needleleaf forests, and boreal evergreen needleleaf forests and crops the next most common (about 9% each). About 40% of the records in the data set were published in the past 10 years (1991-2000), with a further 20% collected between 1981 and 1990. Mean LAI (+/- standard deviation), distributed between 15 biome/land cover classes, ranged from 1.31 +/- 0.85 for deserts to 8.72 +/- 4.32 for tree plantations, with evergreen forests (needleleaf and broadleaf) displaying the highest LAI among the natural vegetation classes. Further information on this data set is available from the link below: Leaf Area Index Data Citation: Cite this data set as follows: Scurlock, J. M. O., G. P. Asner, and S. T. Gower. 2001. Global Leaf Area Index from Field Measurements, 1932-2000. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. [ This document was provided by NASA's Global Change Master Directory. For more information on the source of this metadata please visit http://gcmd.nasa.gov/r/geoss/[GCMD]HISTORICAL_LAI ]

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