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{"Abstract":["In 2003, the U.S. Fish and Wildlife Service conducted a prescribed\n burn over a large part of the northeastern corner of the Sevilleta\n NWR. This study was designed to look at the effect of fire on\n above-ground net primary productivity (ANPP) within different\n vegetation types. Net primary production (NPP) is a fundamental\n ecological variable that measures rates of carbon consumption and\n fixation. Estimates of NPP are important in understanding energy\n flow at a community level as well as spatial and temporal responses\n to a range of ecological processes. While measures of both below-\n and above-ground biomass are important in estimating total NPP, this\n study focuses on above-ground net primary production (ANPP).\n Above-ground net primary production (ANPP) is equal to the change in\n plant mass, including loss to death and decomposition, over a given\n period of time. To measure this change, ANPP is sampled twice a year\n (spring and fall) for all species in each of three vegetation types.\n In addition, volumetric measurements are obtained from adjacent\n areas to build regressions correlating biomass and volume. Three\n vegetation types were chosen for this study: mixed grass (MG), mixed\n shrub (MS) and black grama (G). Forty permanent 1m x 1m plots were\n installed in both burned and unburned sections of each habitat type.\n The core black grama site included in SEV129 was incorporated into\n this dataset as an unburned control, so an additional unburned G\n site was not created. The data for this site is noted as site=G and\n treatment=C (i.e., control). The original mixed-grass unburned plot\n caught fire unexpectedly in the fall of 2009 and was subsequently\n moved to the south. Volumetric measurements are made using\n vegetation data from permanent plots collected in SEV156, "Burn\n Study Sites Quadrat Data for the Net Primary Production Study"\n and regressions correlating biomass and volume constructed using\n seasonal harvest weights from SEV157, "Net Primary Productivity\n (NPP) Weight Data.""]}
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Brooks Range vegetation change from repeat imagery, Alaska, 1970s to 2010s
This data set represents 23 study sites across 22 degrees of longitude along treeline in Alaska's Brooks Range. Each study site was approximately 50 square kilometers in area and sampled with approximately n = 3,000, randomly-placed 6 meter (m) diameter disks. Each of the 63,224 disks were classified by humans into coarse vegetation classes twice, once using 1970s aerial orthophotos (e.g., Alaska High-Altitude Photography) and again using 2010s very-high resolution satellite imagery (e.g., MAXAR World-View). In addition, annual maximum Landsat normalized difference vegetation index (NDVI) values were extracted from a subset of these disks (n = 27,835 from 12 study sites) for Theil-Sen regression on greening trends using the R package LandsatTS.
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- Award ID(s):
- 1748773
- PAR ID:
- 10475447
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- Arctic greening treeline forest tundra ecotone boreal Landsat NDVI shrubs borealization
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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