Dillon-Zuppelli Z. S., Poulson M. E., Graham E. A., Demography and Habitat Associations of the Basalt Cactus Pediocactus nigrispinus, Northwest Science, 2025, 98(1):60-78, doi: 10.3955/046.098.0105
Studies of sites in Washington and Oregon, assessing vegetation, substrate, climate and microorganisms in the biological soil crust. Monitoring of four plots showed a decline in recorded plant numbers and no detected new seedlings. Models indicate the high importance of adult plant persistence, particularly in the 7–10 cm diameter class. A greenhouse trial of germination and seedling survival is also described.