Faculty Advisor

Carrie Woods

Area of Study

Science and Mathematics

Publication Date

Summer 2018


Fallen logs play an essential role in the temperate rainforest ecosystem by providing a safe site for tree establishment, with seedling abundance being much greater on nurse logs than on the ground. This disparity is likely due to differences in competition with bryophytes between microsites. Hylocomium splendens, a moss that dominates the forest floor of temperate rainforests, could potentially inhibit tree seedling growth, but little is known about its microhabitat distribution. We found that stairstep moss grows more abundantly in areas of high canopy openness, and that nurse logs have lower canopy openness in comparison to the forest floor. Fittingly, we also found H. splendens in higher densities on the forest floor than on nurse logs, indicating that the lack of stairstep moss on nurse logs could provide a niche for tree seedlings to grow unhindered by competition. We also eliminated nutrient competition as a potential mode of inhibition of seedlings by stairstep moss, indicating that the most likely form of inhibition is light competition.


University of Puget Sound