Arctic plant ecology: From tundra to polar desert in Svalbard - Unis

Life in the Arctic – a struggle for survival?
Simone Lang 1 , Merete Wiken Dees 2 and Kathrin Bockmühl 3
1 Systems Ecology, Faculteit der Aard­ en Levenswetensschappen, Vrije Universiteit Amsterdam, De
Boelelaan 1085, NL­1081 HV Amsterdam, The Netherlands, simone.lang@ecology.falw.vu.nl,
2 Institutt for plante og miljøvitenskap, Universitetet for miljø og biovitenskap, NO­1432 Ås, Norway,
mwdees@student.umb.no, 3 Department of biology, University of Bergen, Allégaten 41, NO­5001
Bergen, Norway, kathrin.bockmuhl@student.uib.no
Abstract
Are widespread plants in the Arctic widespread due to their wide ecological amplitude
or due to a widespread habitat? To address this question, ecological amplitudes of
plant species across the Arctic were investigated. Vascular plant species composition
and abiotic factors were recorded in 88 plots at 29 sites in 10 different regions on
Svalbard. For each species the ecological amplitude was recorded according to Raups
study carried out at Mesters Vig on North East Greenland in 1969. The ecological
amplitudes of plant species occurring on both Svalbard and Mesters Vig district were
compared. Some differences were found, but this was not the case when Svalbard was
compared to the entire Greenland. pH and bioclimatic zones proved to be the driving
factors for plant distribution on Svalbard. The thermophilic annual Euphrasia
wettsteinii seems to be a sensitive indicator for current climate change scenarios. Our
study showed that widespread taxa do not automatically possess wide amplitudes on
Svalbard and vice versa.
Introduction
Climate change at high latitudes is predicted to be greater and more rapid than in any
other region on Earth. According to the (ACIA 2006) not only will temperatures
change (Przybylak 2007) but also precipitation is expected to increase in wide regions
in the Arctic. Recent observations and experimental studies have supplied evidence
that arctic plants and ecosystems react substantially to rising temperatures (Walker et
al. 2006). Increasing temperatures and rainfall might induce permafrost melting,
leading to a changed hydrology and unstable substrates.
Arctic plants are exposed to extreme amplitudes of environmental factors: early snow
and frost, drought, wind abrasion and extreme temperatures on open patches (Billings
& Mooney 1968). Slope instability can occur as stochastic mass flows as well as slow
continuous process, depending upon the geomorphic circumstances. Low temperature
and short growing seasons result in vegetation dominated by long­lived perennials
that reproduce through vegetative growth, while annuals are rare (Billings & Mooney
1968, Savile 1972). The flora of Svalbard consists of about 170 flowering plant
species and only two of those are annual species: the cold tolerant Koenigia islandica
and the rare, thermophilic hemiparasitic species Euphrasia wettsteinii (Brochmann &
Steen 1999). Euphrasia wettsteinii occurs at its northern limit on Svalbard.
Thermophilic annuals may be good indicators for climate change due to their short
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