Appendix A. Frequency of occurrence (number of plots) of understory taxa in WS1 and WS3, H. J. Andrews Experimental Forest, Oregon, over the study period (1979–2008). HalpernCharles B. A. LutzJames 2016 Frequency of occurrence (number of plots) of understory taxa in WS1 and WS3, H. J. Andrews Experimental Forest, Oregon, over the study period (1979–2008).