Because of what appears to be too much interest in Caribou Island for 'extreme tourism', I removed most of the info from this website a few years ago.

Caribou Island is owned by a private organization for conservation purposes, and they are about imopossible to contact. The island should be left alone as one last remnant of wild Lake Superior. Ushkanii Island, on the other hand, seems unfortunately 'open for business' (to use the term derogatorily).

Feel free contact me if you have questions or would like some CI info for non-tourism purposes.

In the meantime, I'll give you the exciting abstract of the thesis.... And an excerpt - including index, introduction, a little bit of the plant list, and the bibliography, here as small sized 3mb PDF. (it's also much enhanced from the awful double-spaced 'thesis' format, with photos.)

ABSTRACT

Islands are biogeographically exceptional because of their isolation from populations on the mainland as well as the environmental influences of their surrounding waters. While islands in large lakes and those in oceans share many similarities, they also show a number of fascinating differences in their biogeography and ecology. Limited study has been devoted to lake island biology, leaving the degree of uniqueness of ocean and lake island biotas and many other questions to be answered.
A study of two groups of islands has been undertaken for this project; the Ushkanii Islands in Lake Baikal (Russia), and the Caribou Islands in Lake Superior (Canada). The main islands of each of the two locations are of similar size and shape, and both are well covered with their regional variants of the circumboreal forest. They differ in topography, geology, and pedology; in age and origin; in disturbance and human use history; and in distance from mainland. They both represent the most remote islands in their respective lakes. Both islands have climates heavily modified by the lake waters. Both groups have flori?? smaller than comparable areas of the nearby mainland, and both include some disjunct species normally not found in their regions, generally explainable through some microclimatic anomaly. Ushkanii Island has a higher incidence of arctoalpine plants, and is older and much closer to i??sourcei?? areas of such plants, as well as possessing more suitable habitats. Caribou Island has few arctoalpine plants, and is younger and farther removed from a suitable source area.
The vegetational characteristics, physical geographies, and histories of the islands are considered in this study and related to their status as lake islands and insular habitats, and interpretation concerning the phytogeographical influences and development of the islands is presented. Biogeographical and ecological conditions are compared, and ideas are proposed on how these may follow principles similar to other large lake islands. Some ideas on conservation for the islands are also offered.