NATIONALPARK-FORSCHUNG IN DER SCHWEIZ 89 (2000)

Schütz, M.; Krüsi, B.O.; Edwards, .PJ. (eds): Natl.park-Forsch. Schweiz 89, 67 - 88

Tall-herb communities in the Swiss National Park: long-term development of the vegetation

Lägerfluren im Schweizerischen Nationalpark: langfristige Entwicklung der Vegetation

Gérald Achermann, Martin Schütz, Bertil O. Krüsi, Otto Wildi

Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland

Abstract

In the Swiss National Park (SNP), the long-term development of subalpine tall-herb communities was analysed, using 93 relevés from nine permanent plots which were studied at regular intervals over a period of up to 80 years. After the foundation of the SNP in 1914 all grazing by livestock, primarily cattle, was stopped. Subsequently, the standing crop of the tall-herb communities increased rapidly, but until 1940 no major changes in the species composition occurred. After 1940, on five of the nine permanent plots studied, the vegetation changed from a tall-herb community, dominated by common monkshood (Aconitum compactum), good king henry (Chenopodium bonus-henricus), large nettle (Urtica dioeca) or monk's rhubarb (Rumex alpinus), to a short-grass sward dominated by red fescue (Festuca rubra). Most of this transition took place between 1940 and 1960, a period during which the summer population of free-roaming red deer (Cervus elaphus L.) in the Park increased from 4 to 8 individuals per sqkm of vegetation covered area. On three plots the tall-herbs were replaced by tall grasses, chiefly tufted hair-grass (Deschampsia caespitosa). The ninth plot, finally, was not grazed by red deer and remained in the tall-herb stage with common monkshood as the most abundant species. In conclusion, about 20 years of grazing by red deer were sufficient to destroy tall-herb communities created over centuries by grazing of livestock and to replace them by short-grass swards dominated by red fescue. In subalpine grasslands, apparently, the impacts and ecological roles of red deer and livestock are quite different.

Tall-herb communities in the Swiss National Park: long-term development of the vegetation Lägerfluren im Schweizerischen Nationalpark: langfristige Entwicklung der Vegetation

Gérald Achermann, Martin Schütz, Bertil O. Krüsi, Otto Wildi

Abstract

Tall-herb communities in the Swiss National Park: long-term development of the vegetation

Lägerfluren im Schweizerischen Nationalpark: langfristige Entwicklung der Vegetation