Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E7
Höfundar / Authors: Guðrún Óskarsdóttir (1), Þóra Ellen Þórhallsdóttir (1), Hulda Margrét Birkisdóttir (1), Anna Helga Jónsdóttir (1), Kristín Svavarsdóttir (2)
Starfsvettvangur / Affiliations: 1. University of Iceland, 2. The Soil Conservation Service of Iceland
Kynnir / Presenter: Guðrún Óskarsdóttir
Ecosystem development is influenced by both stochastic and deterministic processes, leading to neutral and predictable assembly patterns, respectively. Their relative importance is context dependent and varies temporally and across spatial scales. Here, we compare the roles of these processes in an early successional setting following the massive establishment of a tree species (Betula pubescens). We explore the spatio-temporal dynamics of the first two generations of mountain birch on a flat and apparently homogeneous outwash plain in Iceland that was the recipient of sudden and spatially extensive long-distance dispersal approximately three decades ago. The decadal-scale progress of the population is described, with focus on identifying the extent to which it is limited by deterministic vs. stochastic factors and the spatial and temporal scales at which they operate. We show that deterministic processes across various scales have become increasingly important with time from the largely stochastic initial colonization. Conditions for birch establishment and growth on the seemingly homogenous plain have proven to be highly site-specific, affecting the rate of birch development and, consequently, ecosystem succession. This focus on factors limiting the birch population has been useful in understanding the processes influencing early succession.