{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "Downloaded and clipped by the City in Feb 2026, The City uses these polygons overlayed with the DFW streams to determine the stream buffer for project impacts.\nThe SiteIndex200Year is the field used showing distance to measure from a stream for land use development.", "description": "
The City Layer is named to match the State's source:<\/SPAN><\/P> WDFW_Habitat_Program_SitePotentialTreeHeight_at200years<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>",
"summary": "Downloaded and clipped by the City in Feb 2026, The City uses these polygons overlayed with the DFW streams to determine the stream buffer for project impacts.\nThe SiteIndex200Year is the field used showing distance to measure from a stream for land use development.",
"title": "GIS.WDFW_Habitat_Program_SitePotentialTreeHeight_at200years",
"tags": [
"The Washington Department of Fish and Wildlife riparian ecosystem science synthesis and management recommendations describe how full riparian function can be achieved by delineating a riparian management zone (RMZ) with a width of the Site Potential Tree Height at age 200 (SPTH200). The Site Potential Tree Height Mapping Tool lets a user look up SPTH200 values for their location",
"but the current version has gaps in coverage. In other cases",
"site-level verification is warranted for an available SPTH200 value. For both reasons",
"we (WDFW) are providing this procedure for forestry professionals to determine a site index and thereby SPTH200 from field-based measurements for land use planning under the Growth and Shoreline Management Acts.",
"A site index value characterizes the quality of growing conditions (higher = better). This procedure combines tree age and height field measures (from trees that are not 200 years old) with established growth curves to arrive at a site index value. This site index then allows estimation of SPTH200 using our \u201cSPTH200 Calculator.\u201d",
"To determine site quality using tree height as the indicator",
"appropriate site trees of each species are selected in a stand. The site trees\u2019 heights and ages are measured in the field",
"and then plotted or indexed on species-specific growth curves or tables. These tree height-to-age relationship curves are derived from growth and yield field data and show how the best trees from a variety of sites have grown over time."
],
"type": "",
"typeKeywords": [],
"thumbnail": "",
"url": "",
"minScale": 150000000,
"maxScale": 5000,
"spatialReference": "",
"accessInformation": "The Washington Department of Fish and Wildlife. 2025 Site Potential Tree Height (SPTH) at 200 years is a GIS-based metric used to delineate Riparian Management Zones (RMZs) by estimating the average maximum height of dominant trees. It serves as a key indicator for riparian function and forest productivity.\n\nQuinn, T., G.F. Wilhere, and K.L. Krueger, technical editors. 2020. Riparian Ecosystems, Volume 1: Science Synthesis and Management Implications. Habitat Program, Washington Department of Fish and Wildlife, Olympia.\n\nRentz, R., A. Windrope, K. Folkerts, and J. Azerrad. 2020. Riparian Ecosystems, Volume 2: Management Recommendations. Habitat Program, Washington Department of Fish and Wildlife, Olympia.",
"licenseInfo": "",
"portalUrl": ""
}