Two of the dead cedars near Boyer Avenue in the Arboretum .
says Joey , “ because it will help us compare data at sites with unhealthy trees and answer the question about which environmental parameters are the most important ones to address .”
In addition to information coming through iNaturalist , Joey and his colleagues at WSU will be using data from other sources to refine their analysis . “ Once we have an idea where the dieback hotspots are and what site conditions are vulnerable , we can start to overlay this with climate and soil variables from other data sets that we have .”
AIMING FOR SOLUTIONS “ If we can figure out which environmental parameters best explain the dieback , we can start to investigate solutions ,” says Joey . “ Let ’ s say we determine that heat is the most important one , then we can look for genotypes of the western red cedar that are more tolerant to high heat and use these for restoration to replant on a property . If drought is more important , we can search for droughttolerant plant material .”
Forest Health Watch is already looking ahead to the solutions . Joey is looking for support to create a commongarden study — similar to the WSU ’ s arbutus study — that will test seeds of western red cedar for adaptations throughout the species ’ range .
“ We suspect there is enough genetic variation among different populations that we ’ ll be able to use it as a tool for climate adaptation and sustaining red cedar for future generations ,” adds Joey .
In the meantime , if you have a Thuja plicata in your garden , Joey recommends giving this moisture-loving tree water in the summer , especially during times of drought , and mulching around the tree with wood chips to keep the soil cool and moist . The Forest Health Watch website not only has great information about the dieback problem but also some excellent information about western red cedar ecology and natural history . m
Niall Dunne is the editor of the “ Arboretum Bulletin ” and the communications manager for the Arboretum Foundation .
Summer 2021 v 9