Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Hlynur Steinsson1, Kristín Svavarsdóttir2, Ólöf Birna Magnúsdóttir3, Þóra Ellen Þórhallsdóttir4
Starfsvettvangur / Affiliations: Háskóli Íslands
Kynnir / Presenter: Hlynur Steinsson
This study follows the early stages of primary succession following deglaciation of four glacial forelands in two separate periods, following 7 years of exposure, and revisited one of the year classes after 18 years of exposure. Homogeneity in substrate, comate, elevation and weather conditions across the foreland, and sampling of two separate periods allows for the equivalent of spatial and temporal replicates of the colonisation event. Rapid colonization was observed, with 13 to 42 vascular plant species established within a decade of exposure, dominated by perennial forbs and graminoids. Vascular plant cover increased swiftly in the first decade, followed by bryophytes and lichen in the second decade. Differences in colonisational patterns emerged among the four forelands, showing signs of divergence in functional group accumulation. Homogeneity in inorganic conditions allows for a dis-entanglement of environmental correlates. We suggest seed dispersal and isolation to correlate with divergences in vegetation, indicating colonization of vegetation a proba-bilistic and stochastic process, directed by availability and composition of seed rain.