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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 ]

  • LAI estimates computed from unweighted openness by the canopy program from digitized canopy photographs. [ 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_LAI ]

  • These streamflow data were collected by the HYD-09 science team to support its research into meltwater supply to the soil during the spring melt period. These data were also collected for HYD-09's research into the evolution of soil moisture, evaporation, and runoff from the end of the snowmelt period through freeze up. Data were collected in the BOREAS SSA and NSA from April until October in 1994, 1995, and 1996. Gauges SW1 and NW1 were operated year-round; however, data may not be available for both gauges for all 3 years. [ 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_H09STMGD ]

  • Productivity of a steppe grassland was determined at the Tumentsogt Research Station in Mongolia, between 1982 and 1990. Measurements were made of seasonal dynamics of above-ground live biomass for each year. The Mongolian steppe occupies a major part of eastern Mongolia and northern China, characterised by an arid continental climate with most rain falling between June and August. Land use is dominated by grazing, historically by nomadic pastoralists and more recently for cooperative livestock production. Private livestock grazing has been increasing since 1990. 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_TMN ]

  • The purpose of the SNF study was to improve our understanding of the relationship between remotely sensed observations and important biophysical parameters in the boreal forest. A key element of the experiment was the development of methodologies to measure forest stand characteristics to determine values of importance to both remote sensing and ecology. Parameters studied were biomass, leaf area index, above ground net primary productivity, bark area index and ground coverage by vegetation. Thirty two quaking aspen and thirty one black spruce sites were studied. Sites were chosen in uniform stands of aspen or spruce. The dominant species in the site constituted over 80 percent, and usually over 95 percent, of the total tree density and basal area. Aspen stands were chosen to represent the full range of age and stem density of essentially pure aspen, of nearly complete canopy closure, and greater than two meters in height. Spruce stands ranged from very sparse stands on bog sites, to dense, closed stands on more productive peatlands. Use of multiple plots within each site allowed estimation of the importance of spatial variation in stand parameters. Within each plot, all woody stems greater than two meters in height were recorded by species and the following dimensions were measured: diameter breast height, height of the tree, height of the first live branch, and depth of crown. For each plot, a two meter diameter subplot was defined at the center of each plot. Within this subplot, the percent of ground coverage by plants under one meter in height was determined by species. These data, averaged for the five plots in each site, are presented in the SNF Forest Understory Cover Data (Table) data set in tabular format, e.g. plant species with a count for that species at each site. The same data are presented in this data set (i.e., SNF Forest Understory Cover Data) but are arranged with a row for each species and site and a percent ground coverage for each combination. [ 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_UND_CVR ]

  • The Vegetation Species and Cover Abundance Data Set documents the species present at the FIFE staff data measurement sites. Percent cover is estimated for each species at approximately the time of the IFC's. Disturbances occur over a variety of spatial and temporal scales in North American grasslands, and interactions of these different disturbances affect community structure. Two types of disturbance commonly occur over large spatial scales in grasslands, namely, fire and grazing. Analysis of percent cover of dominant species indicated that composition and heterogeneity was significantly affected by grazing intensity and burning. The effects of disturbances on community structure are not additive, and may not be extrapolated from studies of single factors. The interpretation of patterns in natural communities is clearly scale dependent, and processes may act differently when viewed from different spatial or temporal scales. The effects of scale may not always be predictable; therefore, an understanding of pattern and process at one hierarchical level may not provide useful information about pattern and process at a different hierarchical level. [ 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_VEG_SPEC ]

  • The purpose of the SNF study was to improve our understanding of the relationship between remotely sensed observations and important biophysical parameters in the boreal forest. A key element of the experiment was the development of methodologies to measure forest stand characteristics to determine values of importance to both remote sensing and ecology. Parameters studied were biomass, leaf area index, above ground net primary productivity, bark area index and ground coverage by vegetation. Thirty two quaking aspen and thirty one black spruce sites were studied. Sites were chosen in uniform stands of aspen or spruce. The dominant species in the site constituted over 80 percent, and usually over 95 percent, of the total tree density and basal area. Aspen stands were chosen to represent the full range of age and stem density of essentially pure aspen, of nearly complete canopy closure, and greater than two meters in height. Spruce stands ranged from very sparse stands on bog sites, to dense, closed stands on more productive peatlands. Use of multiple plots within each site allowed estimation of the importance of spatial variation in stand parameters. Within each plot, all woody stems greater than two meters in height were recorded by species and the following dimensions were measured: diameter breast height, height of the tree, height of the first live branch, and depth of crown. For each plot, a two meter diameter subplot was defined at the center of each plot. Within this subplot, the percent of ground coverage by plants under one meter in height was determined by species. These data, averaged for the five plots in each site, are presented in this data set (i.e., SNF Forest Understory Cover Data (Table)) in tabular format, e.g. plant species with a count for that species at each site. The same data are presented in the SNF Forest Understory Cover Data data set but are arranged with a row for each species and site and a percent ground coverage for each combination. [ 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_TAB3_3T ]

  • 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 ]

  • ABSTRACT: Productivity of an ephemeral desert grassland was determined at the Badkhyz Nature Reserve Station in southern Turkmenistan, between 1948 and 1982. Monthly dynamics of above-ground plant biomass were made during the growing season (January-May) from 1948 to 1963, and the record of peak live biomass continues until 1982, with a gap from 1973 to 1976. These data are part of a series of grassland data sets recently assembled and checked by Dr. Tagir Gilmanov, which cover a wide range of climate and "continentality" (increasing maximum summer temperatures, decreasing precipitation) from the North-West to the South-East of the Commonwealth of Independent States (former USSR). 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_BDK ]

  • 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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