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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Research Project #433555

Research Project: Prioritizing Seed Collection Efforts for Timely Response to Tree Mortality, Fire and Climate Change in California-Component 1

Location: Crops Pathology and Genetics Research

Project Number: 2032-21220-006-52-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 15, 2017
End Date: Sep 30, 2018

Using currently available information, identify priority areas for seed collection investment. The proposed study uses existing information on vegetation distribution and exposure under different climate change scenarios to inform R5 Forest Service seed collection prioritization for reforestation in the face of future mass tree mortality and climate change.

To address this need, we will use existing climate, species distribution, and hyperspectral data coupled with climate modeling to determine priority areas for seed collection. We will focus on ponderosa pine (Pinus ponderosa), sugar pine (P. lambertinana), white fir (Abies concolor), red fir (A. magnifica) and Douglas fir (Pseudotsuga menziesii), which are all economically and ecologically important tree species. We will identify populations that may be better adapted to future climate conditions. First, we will identify areas in which populations of each tree species are surviving in conditions at the “extreme” range of their climatic tolerance. We posit that because they have persisted through relatively extreme conditions, they may be better adapted (relative to other populations of the same species) to changing climate stressors like increasing heat or drought stress. We will use weather station data and species distribution data to calculate each species’ climate envelope as an indicator of the range of its climate tolerance. We will then identify locations within each species’ distribution that experience the most extreme climate conditions. An example of output from this approach would be the designation of areas within the current distribution of ponderosa pine in which trees experience an average annual climatic water deficit (an indicator of water stress) that is greater than that experienced by 95% of the species’ distribution. In addition, we will combine USFS vegetation mapping with hyperspectral data from a current USGS Southwest Climate Science Center project and other remote sensing imagery to identify “remnant” populations of each species. Tree species ranges have generally moved up in elevation, but some stands of each species still remain at lower elevations (that is, below what would currently be recognized as the species’ low elevation range limit). These remnant populations that represent the last of their species in an area may be more robust to environmental changes, and collection from these areas should be prioritized to avoid losing the potentially valuable genetic material they currently contain. Seed collected from “extreme populations” (method 1) and “remnant stands” (method 2) can be collected and increased for use in restoration/reforestation efforts. They can also be used in future common garden experiments to determine heritability of desirable physiological and growth characteristics deemed more suitable for reforestation or restoration under future climate conditions. Individuals with desirable traits can then be used in seed increase or classical breeding programs.