Rarity patterns in members of the Lophoziaceae/Scapaniaceae complex occurring North of the Tropics – Implications for conservation

Abstract

Rarity along two of the three parameters of rarity of Rabinowitz (habitat specificity and distribution range) is investigated for the members of the Lophoziaceae/Scapaniaceae complex occurring north of the Tropic of Cancer (174 species). Using a rarity index built on the Shannon–Wiener diversity index, 31 species (18%) are rare on both parameters (most urgent in need of evaluation of threat status and conservation actions), 16 species (9%) are range restricted habitat generalists and 9 species (5%) widespread habitat specialists. The species are most frequently growing on soil, rocks and decaying wood, but no habitat have an exceptional high number of habitat specialists. Four areas do have more habitat specialists than expected from their number of species. The species are most abundant in arctic and boreal areas but also in alpine and oceanic areas. Nepal, East Himalaya (Bhutan and Sikkim) and south-central China (Yunnan and Sichuan) are hot spots both for range restricted species and for habitat specialists.