The role of glacier mice in the invertebrate colonisation of glacial surfaces: the moss balls of the Falljökull, Iceland

Glacier surfaces have a surprisingly complex ecology. Cryoconite holes contain diverse invertebrate communities while other invertebrates, such as Collembola often graze on algae and windblown dead organic on the glacier surface. Glacier mice (ovoid unattached moss balls) occur on some glaciers worldwide. Studies of these glacier mice have concentrated on their occurrence and mode of formation. There are no reports of the invertebrate communities. But, such glacier mice may provide a suitable favourable habitat and refuge for a variety of invertebrate groups to colonise the glacier surface. Here we describe the invertebrate fauna of the glacier mice (moss balls) of the Falljökull, Iceland. The glacier mice were composed of Racomitrium sp. and varied in size from 8.0 to 10.0 cm in length. All glacier mice studied contained invertebrates. Two species of Collembola were present. Pseudisotoma sensibilis (Tullberg, 1876) was numerically dominant with between 12 and 73 individuals per glacier mouse while Desoria olivacea (Tullberg, 1871) occurred but in far lower numbers. Tardigrada and Nematoda had mean densities of approximately 200 and 1,000 respectively. No Acari, Arachnida or Enchytraeidae were observed which may be related to the difficulty these groups have in colonizing the glacier mice. We suggest that glacier mice provide an unusual environmentally ameliorated microhabitat for an invertebrate community dwelling on a glacial surface. The glacier mice thereby enable an invertebrate fauna to colonise an otherwise largely inhospitable location with implications for carbon flow in the system

Social-ecological timelines to explore human adaptation to coastal change

Through the construction of a socio-ecological timeline for the Porsanger fjord ecosystem, this article illustrates the different ways in which environmental and social–ecological changes have influenced the adaptations of rural households in coastal Sami communities in Finnmark, north Norway. The main finding is that, although environmental change in the form of seal invasions and dwindling fish stocks directly impacted the fisheries, the introduction of a new vessel quota system decisively changed adaptive capacity and coastal Sami household adaptation strategies. These changes represented a tipping point for the social–ecological system in the period between 1986 and 1990. It is thus important to discuss the ways in which governance systems may facilitate actions to adapt to climate and biodiversity change and foster sustainable rural livelihood systems in coastal Norway. Based on traditional and local ecological knowledge on the state of the ecosystem prior to the tipping point, two relevant actions to increase the resilience of the system were identified: ensuring the possibility of re-entry into fisheries as part of rural livelihood combinations, and ecological restoration of kelp beds. Flexible diversification of livelihoods allows exploitation of a range of adjacent species without large investments in a fossile fuel-driven fisheries economy. Investing in regrowth of macroalgae to foster cod nursery areas and increase carbon sequestration can be a relevant alternative for communities that are interested in contributing to climate change mitigation on a larger scale.publishedVersio