ABSTRACT. We developed a conceptual framework for evaluating the process of ecological restoration and applied it to 10 examples of restoration projects in the northern hemisphere. We identified three major phases, planning, implementation, and monitoring, in the restoration process. We found that evaluation occurred both within and between the three phases, that it included both formal and informal components, and that it often had an impact on the performance of the projects. Most evaluations were short-term and only some parts of them were properly documented. Poor or short-term evaluation of the restoration process creates a risk that inefficient methods will continue to be used, which reduces the efficiency and effectiveness of restoration. To improve the restoration process and to transfer the knowledge to future projects, we argue for more formal, sustained evaluation procedures, involving all relevant stakeholders, and increased and improved documentation and dissemination of the results.

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. A free Plain Language Summary can be found within the Supporting Information of this article.

1. Macroinvertebrate assemblages were studied in the glacial river West‐Jökulsá, originating from the Hofsjökull Ice Cap in central Iceland at an altitude of 860 m. Sampling sites were distributed from the source to 45 km downstream at 160 m a.s.l. Comparative studies were carried out on non‐glacial rivers and tributaries in the area, at similar altitudes and distances from the glacial source. 2. Detrended correspondence analysis (DCA) demonstrated that species composition of benthic macroinvertebrates was related to the distance from the glacier. Assemblages at sampling sites furthest from the glacier were similar in species composition to sites in non‐glacial rivers. Temporal variation was small compared with longitudinal zonation. 3. Based on canonical correspondence analysis (CCA) of data from the main glacial river, distance from the glacier, altitude, bryophyte biomass and the Pfankuch Index of channel stability were the measured explanatory variables having a significant effect on the structure of macroinvertebrate assemblages, accounting for 31% of the total variation in the data set. When data from all the rivers were analysed, altitude, bryophyte biomass, channel slope, suspended sediment concentration and maximum water temperature explained 21% of the variance. 4. Macroinvertebrate communities were in general agreement with the predictions of the conceptual model of Milner & Petts (1994) for the upstream reaches. The assemblages consisted mainly of Orthocladiinae and Diamesinae (Chironomidae), although other taxa such as Simuliidae, Plecoptera and Trichoptera were also found in low numbers. Shredders were lacking from the benthic communities, apparently because of continued glacial influence in the river even 45 km downstream from the glacier and lack of allochthononus inputs from riparian vegetation.

ABSTRACT. We analyzed the main drivers for ecological restoration in Iceland from 1907 to 2010 and assessed whether the drivers have changed over time and what factors might explain the changes, if any. Our study was based on a catalogue of 100 restoration projects, programs, and areas, representing 75% to 85% of all restoration activities in Iceland. Catastrophic erosion was an early driver for soil conservation and restoration efforts that still ranked high in the 2000s, reflecting the immense scale of soil erosion and desertification in Iceland. Socioeconomic drivers such as farming and the provision of wood products were strong motivators of ecological restoration over most of the 20th century, although their relative importance decreased with time as the number and diversity of drivers increased. In the 1960s and 1970s, the construction of hard infrastructure, and moral values such as improving the aesthetics of the countryside and "repaying the debt to the land" emerged as motivations for restoration actions. In the late 1990s, the United Nations Climate Change Convention became a driver for restoration, and the importance of nature conservation and recreation increased. Technological development and financial incentives did not show up as drivers of ecological restoration in our study, although there are some indications of their influence. Furthermore, policy was a minor driver, which might reflect weak policy instruments for ecological restoration and some counteractive policies.

Question: We investigated colonisation filters in early plant community development on a glacial outwash plain. We asked if these were related to seed limitation or to a lack of safe sites, if topographical heterogeneity affected species patchiness and how species life cycles influence successional trajectories. Location: An outwash plain (Skeiðarársandur) in southeast Iceland. Methods: We identified surface heterogeneity at two different scales, ca. 10–15 cm (larger stones and established plants) and ca. 50 m (shallow depressions representing dry river beds) at two study sites. We quantified species cover, flowering plant density, seed production, seed rain, seed bank density, seedling emergence and seedling survival from June 2005 to June 2007 for the whole plant community, and measured seed production for five species. Results: Mean vegetation cover was <2.5% at the sites. Low emergence rates and high seedling mortality were the two main recruitment filters. Only 1.4% of seedlings emerging in 2005 survived into the 2007 growing season. Topographical heterogeneity had little effect on plant colonisation. High annual variation was recorded, and the two study sites (ca. 2 km apart) differed in their colonisation success. Of the five species, establishment of Cerastium alpinum and Silene uniflora was most limited by lack of seeds, whereas establishment of Luzula spicata, Poa glauca and Rumex acetosella was most limited by safe sites. Conclusions: We conclude that colonisation processes and patterns in early primary succession on Skeiðarársandur were largely influenced by stochastic factors.