Soil Carbon Accumulation and CO 2

Experimental plots were established on severely eroded land surfaces in Iceland in 1999 to study the rates and limits of soil carbon sequestration during restoration and succession. The carbon content in the upper 10 cm of soils increased substantially during the initial eight years in all plots for which the treatments included both fertilizer and seeding with grasses, concomitant with the increase in vegetative cover. In the following five years, however, the soil carbon accumulation rates declined to negligible for most treatments and the carbon content in soils mainly remained relatively constant. We suggest that burial of vegetated surfaces by aeolian drift and nutrient limitation inhibited productivity and carbon sequestration in most plots. Only plots seeded with lupine demonstrated continued long-term soil carbon accumulation and soil CO2 flux rates significantly higher than background levels. This demonstrates that lupine was the sole treatment that resulted in vegetation capable of sustained growth independent of nutrient availability and resistant to disruption by aeolian processes

Fra seddelsamling til database: Leksikografisk analyse af islandske verber

Ved Orðabók Haskólans- Leksikografisk institut- i Reykjavfk arbejder man på en stor historisk ordbog over islandsk. Hovedkilden er en stor seddelsamling der er baseret på traditionel excerpering af tekster samt andre mindre særsamlinger. Disse samlinger bliver siden kompletteret med materiale fra maskinlæsbare tekster når det viser sig at være brug for flere og/eller bedre eksempler for at få frem en fuldstændigere beskrivelse af ordenes mening og brug. Som første trin i redaktionen bliver der lagt hovedvægt på verbernes analyse og udarbejdelse. I det følgende beskriver vi analyseprocessen og redaktionsarbejdet og fortæller om vores erfaring af at forene ny teknologi og arbejdsmetoder med gammelt materiale

The Nordic Aichi restoration project : How can the Nordic countries implement the CBD-target on restoration of 15% of degraded ecosystems within 2020?

The Convention of Biological Diversity commits the parties to halt the loss of biodiversity within 2020. For accomplishing this task, the Aichi targets have been established. Aichi target 15 aims at restoring 15% of damaged ecosystems by 2020. The Nordic countries are parties to CBD, and committed to the Aichi targets. This project will establish a basis that may be used by the management and political authorities in the Nordic countries for achieving Aichi target 15 on restoration of degraded ecosystems. The report explores the possibilities, limitations and challenges on how ecological restoration can contribute to the Aichi target, based on available knowledge and existing statistics on degraded land and restoration experiences in the Nordic countries and Estonia. This is intended as a contribution for future work at the national level and in local communities

Stomping in silence: Conceptualizing trampling effects on soils in polar tundra

Ungulate trampling modifies soils and interlinked ecosystem functions across biomes. Until today, most research has focused on temperate ecosystems and mineral soils while trampling effects on cold and organic matter‐rich tundra soils remain largely unknown. We aimed to develop a general model of trampling effects on soil structure, biota, microclimate and biogeochemical processes, with a particular focus on polar tundra soils. To reach this goal, we reviewed literature about the effects of trampling and physical disturbances on soils across biomes and used this to discuss the knowns and unknowns of trampling effects on tundra soils. We identified the following four pathways through which trampling affects soils: (a) soil compaction; (b) reductions in soil fauna and fungi; (c) rapid losses in vegetation biomass and cover; and (d) longer term shifts in vegetation community composition. We found that, in polar tundra, soil responses to trampling pathways 1 and 3 could be characterized by nonlinear dynamics and tundra‐specific context dependencies that we formulated into testable hypotheses. In conclusion, trampling may affect tundra soil significantly but many direct, interacting and cascading responses remain unknown. We call for research to advance the understanding of trampling effects on soils to support informed efforts to manage and predict the functioning of tundra systems under global changes.</li

Stomping in silence:conceptualizing trampling effects on soils in polar tundra

Abstract 1. Ungulate trampling modifies soils and interlinked ecosystem functions across biomes. Until today, most research has focused on temperate ecosystems and mineral soils while trampling effects on cold and organic matter‐rich tundra soils remain largely unknown. 2. We aimed to develop a general model of trampling effects on soil structure, biota, microclimate and biogeochemical processes, with a particular focus on polar tundra soils. To reach this goal, we reviewed literature about the effects of trampling and physical disturbances on soils across biomes and used this to discuss the knowns and unknowns of trampling effects on tundra soils. 3. We identified the following four pathways through which trampling affects soils: (a) soil compaction; (b) reductions in soil fauna and fungi; (c) rapid losses in vegetation biomass and cover; and (d) longer term shifts in vegetation community composition. 4. We found that, in polar tundra, soil responses to trampling pathways 1 and 3 could be characterized by nonlinear dynamics and tundra‐specific context dependencies that we formulated into testable hypotheses. 5. In conclusion, trampling may affect tundra soil significantly but many direct, interacting and cascading responses remain unknown. We call for research to advance the understanding of trampling effects on soils to support informed efforts to manage and predict the functioning of tundra systems under global changes