Hackelia venusta: An investigation into the site characteristics of Washington State’s rarest plant

Background/Question/Methods

Hackelia venusta is the most endangered endemic plant species in aWashington State. Preservation of this species is contingent upon a better understanding of its site characteristics. A primary objective of this study is to identify the site soil characteristics critical to Hackelia venusta’s survival. This study will be essential to the development of effective management protocols aimed at ensuring the survival of this rare species.

The known populations of H. venusta are confined to the eastern slopes of the Central Cascades with most populations occurring on steep, unstable slopes. As such, the investigation of this plant will require extreme caution so as not to disturb any currently existing individuals.  Soil pits will be placed in strategic locations designed to capture variation within the landscape and minimize disturbance. Samples from these pits will provide basic information on important physical and chemical soil characteristics including soil moisture, texture, pH, nutrient composition and cation exchange capacity. We also plan to excavate an individual plant to investigate the root system including the extent and morphology, and presence of mycorrhizal symbionts.  We believe these factors may be playing a significant role in the continued existence of the species. 

Results/Conclusions

Preliminary results indicate that H.venusta’s root system consists of a branching taproot with a diverse fine-root system. Soils are typically coarse-textured on slopes that are more prone to erosion.  Final results will serve to better describe the unique soil properties specific to the sites where remaining populations of H.venusta are located. These results will be used to identify potential planting locations for restoration management.