Fig. 6

Site level (Site1-3) Canopy Height Models (CHMs, in meters; a.1–3) and GBM-predicted probabilities of Erigeron spp. occurrence (b.1–3), Solidago spp. occurrence (c.1–3) and both genera co-occurrence (Co-invasion; d.1–3); (b.1–3) and (c.1–3) are probability gradient maps, while (d.1–3) are binarized maps for both the Asteraceae genera; in b-d, dark colors denote low or zero probability of occurrence and bright colors indicate high probability of occurrence.