Experiments Are Revealing a Foundation Species: A Case Study of Eastern Hemlock (Tsuga canadensis)
Figure 2
Winter minimum temperatures (1960–2013) at Groton, Connecticut (41.35°N, −72.03°W; green symbols), Storrs, Connecticut (41.81°N, −72.25°W; blue symbols), and Harvard Forest (HFR; black symbols) (42.53°N, −72.19°W) along with approximate establishment dates of the hemlock woolly adelgid (Adelges tsugae) in southern Connecticut and at Harvard Forest (green and black arrows). Solid lines are best-fit linear temperature trends; the dashed red line at −25°C indicates the LT50 for the hemlock woolly adelgid—the temperature at which 50% mortality of the adelgid is expected [46, 47].
