The Western monarch butterfly population that overwinters in California is in a state of collapse from a panoply of causes, including pesticide use, climate change, land use-change, and deterioration of the overwintering sites along the coast. Stu has been working with overwintering monarchs since 1990, using hemispherical (fisheye) photography to quantify canopy structure and map wind and sun exposure within the sites. As of summer 2020, Creekside Science is assessing more than 20 monarch sites from Sonoma to Orange Counties, working with various cities, California State Parks, Resource Conservation Districts, and the Xerces Society to assess the current conditions of groves and to develop long-term management plans. One fascinating aspect is that conserving monarchs requires thoughtful management of specific non-native eucalyptus forests, which the monarchs have occupied because eucalyptus groves provide the exacting microclimatic conditions sought by the butterflies.
Here is Stu with his venerable fisheye camera rig, while he and Chris were bushwhacking through the dense poison oak understory of a Eucalyptus grove at Andrew Molera State Park in Big Sur. Stu had worked this site in 2001, and noted densification of the forest that will be captured with the fisheye photos and a novel application of LiDAR (laser mapping from aircraft).
A LiDAR image of Andrew Molera, looking like a 19th Century Japanese woodblock print, provides 3-D structural information. Note the peaked roof of the Cooper Cabin, built in 1861, and the large trunks of the eucalyptus trees planted around the same time that the cabin was constructed.
Here is a fisheye photo from which canopy openings in different directions can be used to estimate wind and sun penetration. The cabin is to the upper right, and the Santa Lucia Range can be seen through the large trees surrounding the cabin.
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