e-Learning portal for Arctic Biology

1.3.4 Succession gradients

In Arctic marginal environments, successional pattern deviates from the classical model for directional change and replacement of species (Matthews 1978; Svoboda & Henry, 1987). Under high climatic stress competition is reduced, and directional, non-replacement succession becomes more common, where initial species remain, but new species are added through the succession (Svoboda & Henry, 1987; Jones & Henry, 2003). Previous studies from glacier forelands in Svalbard have suggested that colonisation of both plants and root-associated fungi follow this directional, non-replacement succession model (Hodkinson et al., 2003; Davey et al., 2015).

In the Arctic, pioneer plants take decades to colonize. The first species to establish in front of retreating glaciers are lichens, mosses and cyanobacteria, forming what we call biological soil crusts. These soil crusts significantly affect soil formation in Arctic forelands. 

Soil crusts starts the soil development in recently deglaciated areas
According to Svoboda and Henry (1987), can the progress of succession in marginal habitats like Arctic glacier forelands be defined as a function of the biological driving forces (which are intrinsic to the invading and establishing species - e.g. how efficient colonizer and competitors they are), and the environmental resistances (= sum of the adverse factors hindering the success of species establishment).

Davey ML, Blaalid R, Vik U, Carlsen T, Kauserud H & Eidesen PB (2015) Primary succession of Bistorta vivipara (L.) Delabre (Polygonaceae) root-associated fungi mirrors plant succession in two glacial chronosequences. Environmental Microbiology 17: 2777-2790.

Hodkinson ID, Coulson SJ & Webb NR (2003) Community assembly on proglacial chronosequences in the high Arctic: vegetation and soil development in north west Svalbard. Journal of Ecology 91: 651-663.

Jones GA & Henry GHR (2003) Primary plant succession on recently deglaciated terrain in the Canadian High Arctic. Journal of Biogeography 30: 277-296.

Matthews JA (1978) Plant colonisation patterns on a gletschervorfeld, southern Norway: a meso-scale geographical approach to vegetation change and phytometric dating. Boreas 7: 155-178.

Svoboda J & Henry GHR (1987) Succession in Marginal Arctic Environments. Arctic and Alpine Research 19: 373-384.