Trampling Effects on Bryophytes: Trail Surveys and Experiments
1980; American Bryological and Lichenological Society; Volume: 83; Issue: 3 Linguagem: Inglês
10.2307/3242440
ISSN1938-4378
Autores Tópico(s)Lichen and fungal ecology
ResumoA survey was made of bryophytes associated with trails near Moun- tain Lake, Virginia, totaling 35 species, all common in the adjacent forest. The species having highest importance values on the trails were, in order of decreasing importance values: Hypnum imponens, Dicranella heteromalla, Thuidium delica- tulum, Atrichum angustatum, Polytrichum ohioense, Leucobryum glaucum, and Callicladium haldanianum. To assess trampling resistance in bryophytes, experi- mental plots of Polytrichum commune, Ditrichum pallidum, and Sphagnum recur- vum were subjected to known levels of trampling by humans. Sphagnum recurvitm was the most vulnerable species, fragmenting after 130 passages. After 4200 pas- sages Polytrichum commune showed considerable internal damage to portions of the stem and fragmentation of its leaves while Ditrichum pallidum showed little damage-the small shoots evidently cushioned by each other and by burial in the soil. After 19 days, regeneration of new shoots from the rhizome-like stems of Polytrichum commune was readily apparent in the field, and microscopic exami- nation showed the production of secondary protonemata and shootbuds from leaf fragments in the muck. Secondary protonemata and shootbuds were produced from stems and leaves of intact plants and of shoot fragments of Ditrichum pal- lidum. Trample-resistant structural features and high regenerative abilities ap- parently contribute to the importance of bryophytes on trails as potential inhibitors of soil erosion.
Referência(s)