Wallenius Tuomo, Bjerke Jarle W, Erlandsson Rasmus, Kolari Tiina H M, Räsänen Aleksi, Tahvanainen Teemu, Tømmervik Hans, Winquist Emelie, Virtanen Tarmo
University of Helsinki, Biocenter 3, Viikinkaari 1, P.O. Box 65, 00014, Helsinki, Finland.
Department of Arctic Ecology, FRAM -High North Research Centre for Climate and the Environment, Norwegian Institute for Nature Research (NINA), P.O. Box 6606, 9296, Langnes, Tromsø, Norway.
Ambio. 2025 Oct;54(10):1683-1704. doi: 10.1007/s13280-025-02171-3. Epub 2025 May 13.
We analysed the history behind the current contrasting lichen covers of two adjacent reindeer herding districts at the Finnish-Norwegian border. We conducted vegetation field inventories across the border fence and reconstructed a lichen cover history from 1959 to 2020 using aerial and satellite images. The oldest images showed only a slight difference in lichen cover between the different sides of the border fence. Since the late 1950s, lichen cover has decreased in both districts. At present, lichen biomass is approximately three times greater in in the Norwegian winter pasture than in the Finnish herding district, which has less strictly defined seasonal pastures. A lichen biomass model indicated that lichen intake by reindeer cannot explain the decline in lichen biomass in either of the districts. We suggest that the lichen decline is mainly due to trampling and foraging-induced loss, while other unknown ecological and climatological factors may also be involved.
我们分析了芬兰 - 挪威边境两个相邻驯鹿放牧区当前地衣覆盖情况形成对比的背后历史。我们在边境围栏两侧进行了植被实地清查，并利用航拍和卫星图像重建了1959年至2020年的地衣覆盖历史。最古老的图像显示边境围栏两侧的地衣覆盖情况仅有细微差异。自20世纪50年代末以来，两个地区的地衣覆盖面积均有所减少。目前，挪威冬季牧场的地衣生物量大约是芬兰放牧区的三倍，芬兰放牧区的季节性牧场定义没那么严格。一个地衣生物量模型表明，驯鹿对地衣的摄取量无法解释两个地区中任何一个地区地衣生物量的下降。我们认为地衣数量减少主要是由于践踏和觅食导致的损失，同时可能还涉及其他未知的生态和气候因素。
