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TRM Seed Zone Applications

This site allows end-users to view and acquire data on seed zones for use in plant material development, gene conservation and native plant restoration activities. Users can also evaluate seed zones in relation to other map services and wildland threats published by WWETAC such as climate change projections or wildfire risk.


TRM Seed Zone WebMap

The Seed Zone WebMap is an interactive 2D map that displays in your internet web browser - no software installation is required. To navigate around the map, Left-click and drag your mouse to pan, use your mouse wheel or the slider control in the upper left to zoom, and Shift-Left click to drag to define a new map extent. Explore the tools on the left, they control layers displayed, background map, and more.


Mobile Seed Zone Mapping

Mobile mapping applications for Andorid and iOS devices have been developed to bring seed zones out into the field. Click the above link to learn more.


Seed Zone Map Layers


Provisional Seed Zones - Deploying well adapted and ecologically appropriate plant materials is a core component of a successful restoration project. However, restoration practitioners are often forced to deploy plant species on the landscape for which no seed transfer guidelines have been established through genetic research. So what are practitioners to do when no seed transfer guidelines have been established for a species of interest? Bower et al (2014) have developed generalized provisional seed zones that can be applied to any plant species to help guide seed movement. These seed zones are based on the intersection of high resolution climatic data. Climate data was obtained from the PRISM Climate Group and included raster files for mean monthly minimum and maximum temperature and annual precipitation based on climate normals for the period 1981-2010 with an 800m x 800m cell size. Data was imported into ArcMap version 10 (ESRI, Redlands, CA) for all analyses. Minimum winter temperature was determined as the minimum value per cell from December through February and was classified into 5oF (2.8oC) bands that ranged from <10o - >55o F (-12.2o - 12.8oC). These intervals were chosen to reflect the familiar temperature bands used in the USDA plant hardiness zone map (Cathey 1990, ). Aridity was calculated as the annual heat:moisture index (AH:M) following the method of Hamann and Wang (2005) as mean annual temperature plus 15 C (to obtain positive values) divided by mean annual precipitation in meters (mean annual temperature = (mean maximum temperature + mean minimum temperature) / 2). AH:M was then divided into six discrete classes (<2, 2-3, 3-6, 6-12, 12-30, and >30) where higher values indicate more arid environments. The Union function of ArcMap was used to intersect the minimum winter temperature with the AH:M layer to create unique climatically delineated (temperature-aridity) provisional seed zones. The intersection of these two variables, each classified into discrete bands, results in the delineation of 64 provisional seed zones for the continental United States. These zones represent areas of relative climatic similarity, and movement of seed within these zones should help to minimize maladaptation. Superimposing Omernick’s level III ecoregions over these seed zones helps to distinguish areas that are similar climatically yet different ecologically. These provisional seed zones should be considered a starting point as guidelines for seed transfer, and should be utilized in conjunction with appropriate species specific information as well as local knowledge of microsite differences.

Seed Zone Data

Climate-matched Seed Zones - Land management agencies are increasing the use of native plant materials for vegetation treatments to restore ecosystem function and maintain natural ecological integrity. This shift toward the use of natives has highlighted a need to increase the diversity of materials available. A key problem is agreeing on how many, and which, new accessions should be devel-oped. Here we describe new methods that address this problem. Our methods use climate data to calculate a climate similarity index between two points in a defined extent. This index can be used to predict relative performance of available accessions at a target site. In addition, the index can be used in combination with standard cluster analysis algorithms to quantify and maximize climate coverage (mean climate similarity), given a modeled range extent and a spec-ified number of accessions. We demonstrate the utility of this latter feature by applying it to the extents of 11 western North American species with proven or potential use in restoration. First, a species- specific seed transfer map can be readily generated for a species by predicting perfor-mance for accessions currently available; this map can be readily updated to accommodate new accessions. Next, the increase in climate coverage achieved by adding successive accessions can be explored, yielding information that managers can use to balance ecological and economic considerations in determining how many accessions to develop. This approach identifies sam-pling sites, referred to as climate centers, which contribute unique, complementary, climate coverage to accessions on hand, thus providing explicit sampling guidance for both germplasm preservation and research. We examine how these and other features of our approach add to existing methods used to guide plant materials development and use. Finally, we discuss how these new methods provide a framework that could be used to coordinate native plant materi-als development, evaluation, and use across agencies, regions, and research groups.

Seed Zone Data

Great Basin Edited Seed Zones - Provisional seed zones for grasses and forbs for the Great Basin area have been edited based on expert local knowledge. Several seed zones that covered only very small geographic areas were merged, and the zones in the Northern Great Basin and Snake River Plain Level III ecoregion were combined. Zones were combined based on temperature and/or precipitation. For example, all zones in temperature bands 60 degrees F. or lower were combined, and all zones <10" annual precipitation were combined based on whether the temperature band was above or below 80 degrees F. These edited provisional seed zones for the Northern and Central Great Basin areas can be downloaded by clicking on the link below.

Seed Zone Data


Empirical Seed Zones from Common Garden Studies - For the common garden approach to developing seed zones, methods are outlined by Campbell (1986), Rehfeldt (1986) and St Clair et al. (2005) for conifer species. Similar techniques have been used by Erickson et al. (2004) for blue wildrye and for mountain brome (Johnson et al. 2010). First, a comprehensive collection of germplasm is completed to represent the diverse geographic and climatic features of the targeted region. Second, plants from collection locations across the region are evaluated in common gardens for production, morphology, phenology, and physiological traits. And third, statistical analyses are completed to develop regression models that link genetic variation across the landscape with collection location environments. Regression models are projected and mapped to delineate seed zones for studies species and geographic areas.

More on empirical seed zones     Seed Zone Data