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1.
We report on a revisit in 2009 to sites where vegetation was recorded in 1967 and 1970 on Disko Island, West Greenland. Re-sampling
of the same clones of the grass Phleum alpinum after 39 years showed complete stability in biometrics but dramatic earlier onset of various phenological stages that were
not related to changes in population density. In a fell-field community, there was a net species loss, but in a herb-slope
community, species losses balanced those that were gained. The type of species establishing and increasing in frequency and/or
cover abundance at the fell-field site, particularly prostrate dwarf shrubs, indicates a possible start of a shift towards
a heath, rather than a fell-field community. At the herb-slope site, those species that established or increased markedly
in frequency and/or cover abundance indicate a change to drier conditions. This is confirmed both by the decrease in abundance
of Alchemilla glomerulans and Epilobium hornemanii, and the drying of a nearby pond. The causes of these changes are unknown, although mean annual temperature has risen since
1984. 相似文献
2.
Leif Kullman 《Ambio》2010,39(2):159-169
Alpine plant life is proliferating, biodiversity is on the rise and the mountain world appears more productive and inviting
than ever. Upper range margin rise of trees and low-altitude (boreal) plant species, expansion of alpine grasslands and dwarf-shrub
heaths are the modal biotic adjustments during the past few decades, after a century of substantial climate warming in the
Swedish Scandes. This course of biotic landscape evolution has reached historical dimensions and broken a multi-millennial
trend of plant cover retrogression, alpine tundra expansion, floristic and faunal impoverishment, all imposed by progressive
and deterministic neoglacial climate cooling. Continued modest warming over the present century will likely be beneficial
to alpine biodiversity, geoecological stability, resilience, sustainable reindeer husbandry and aesthetic landscape qualities.
These aspects are highlighted by an integrative review of results from long-term monitoring of subalpine/alpine vegetation
in the Swedish Scandes. This forms the basis for some tentative projections of landscape transformations in a potentially
warmer future. Notably, these results and projections are not necessarily valid in other regions and differ in some respects
from model predictions. Continued monitoring is mandatory as a basis for generation of more realistic vegetation and ecosystem
models. 相似文献