ChapterPDF Available

Ecosystem degradation and restoration of birch woodlands in Iceland

Authors:
Aradottir, A. L. and O. Arnalds.
2001. Ecosystem degradation
and restoration of birch
woodlands in Iceland. Pages
293-306 in F. E. Wielgolaski,
editor. Nordic Mountain Birch
Ecosystems. UNESCO, Paris,
and Parthenon Publishing,
Carnforth.
... More than 37,000 km 2 are barren deserts, some of which have formed after settlement (874 AD). The vegetation composition of rangelands reects sheep grazing, with species tolerant to grazing dominating most communities, such as small woody species and sedges (see e.g., Aradóttir and Arnalds, 2001). Birch woodlands used to cover a large proportion of the country (25–40%, see Aradóttir and Eysteinsson, 2005) but now only comprise about 1% due to land degradation processes (Aradóttir and Arnalds , 2001; Aradóttir and Eysteinsson, 2005). ...
... The vegetation composition of rangelands reects sheep grazing, with species tolerant to grazing dominating most communities, such as small woody species and sedges (see e.g., Aradóttir and Arnalds, 2001 ). Birch woodlands used to cover a large proportion of the country (25–40%, see Aradóttir and Eysteinsson, 2005) but now only comprise about 1% due to land degradation processes (Aradóttir and Arnalds, 2001; Aradóttir and Eysteinsson, 2005). Active eolian processes lead to a steady ux of eolian materials that are deposited to the surface of existing soils at a rate of <0.001 to >1 mm yr −1 (Thorarinsson, 1961; Arnalds, 2000), continuously modifying the soil environment by recharging the system with fresh parent material. ...
... Fully vegetated systems have in places been replaced by barren deserts with limited plant production . A large part of the vegetated systems are also degenerated, with poorer plant composition such as heath and sedges, often with abundance of erosion spots and other erosion features, replacing birch-, willow-, or owery plant dominated systems in drylands (Arnalds, 1987; Aradóttir and Arnalds, 2001). ...
Article
Full-text available
Icelandic soils are dominated by Andosols when covered by vegetation, Vitrisols in desert areas (Icelandic classification scheme), and highly organic Histosols in some wetland areas. Andosols are not common in Europe but are found in active volcanic areas of the world. They develop distinctive properties such as high organic content, extremely high water holding capacity and, lack of cohesion. Icelandic soils are in many ways special oil a global scale due to the environmental conditions for soil development, which include: i) basaltic tephra parent material; ii) steady eolian sedimentation of volcanic materials to the soil surface; and iii) many freeze-thaw cycles acting on frost susceptible soils, causing intense cryoturbation. Iceland has extensive barren, desert areas in a cold-humid climate that comprise the largest sandy tephra areas oil Earth. Many of the wetland soils have a distinctive combination of andic (volcanic soil properties) and histic (organic) properties. Soil erosion and desertification is more active in Iceland than in all), other Northern European country. Erosion has severely degraded many ecosystems with formation of barren surfaces devoid of vegetation in several areas.
... Agriculture, forestry, and infrastructure development are the major land use pressures in Iceland. The onset of anthropogenic influences following the settlement of Iceland in the ninth century, combined with a harsh climate, volcanic soils, and fragile ecosystems, led to catastrophic ecosystem degradation and soil erosion, and the loss of more than 95% of native birch woodlands (Aradottir and Arnalds 2001, Arnalds et al. 2001, Gisladóttir et al. 2010). During the 20th century, more than half of the natural wetlands in Iceland's lowland areas were drained for agricultural purposes (Óskarsson 1998), and the woodland remnants were further fragmented by the planting of exotic trees (Blöndal and Gunnarsson 1999). ...
... Agriculture, forestry, and infrastructure development are the major land use pressures in Iceland. The onset of anthropogenic influences following the settlement of Iceland in the ninth century, combined with a harsh climate, volcanic soils, and fragile ecosystems, led to catastrophic ecosystem degradation and soil erosion, and the loss of more than 95% of native birch woodlands (Aradottir and Arnalds 2001, Arnalds et al. 2001, Gisladóttir et al. 2010). During the 20th century, more than half of the natural wetlands in Iceland's lowland areas were drained for agricultural purposes (Óskarsson 1998), and the woodland remnants were further fragmented by the planting of exotic trees (Blöndal and Gunnarsson 1999). ...
... Heathland and grassland are currently the dominant habitat types in Iceland, where most of the forests have been destroyed. The highest land use pressure comes from overgrazing, which, in combination with geographic factors, has resulted in extensive deserted areas (Arnalds et al. 2001). Thus, the efforts and scale of ecological restoration of eroded land in Iceland have been larger than in any other Nordic country, more in line with the scale and strategies of restoration in the North American prairies and the Australian grasslands (Prober et al. 2005, Mabry et al. 2010). ...
Article
Full-text available
An international overview of the extent and type of ecological restoration can offer new perspectives for understanding, planning, and implementation. The Nordic countries, with a great range of natural conditions but historically similar social and political structures, provide an opportunity to compare restoration approaches and efforts across borders. The aim of this study was to explore variation in ecological restoration using the Nordic countries as an example. We used recent national assessments and expert evaluations of ecological restoration. Restoration efforts differed among countries: forest and peatland restoration was most common in Finland, freshwater restoration was most common in Sweden, restoration of natural heathlands and grasslands was most common in Iceland, restoration of natural and semi-cultural heathlands was most common in Norway, and restoration of cultural ecosystems, mainly abandoned agricultural land, was most common in Denmark. Ecological restoration currently does not occur on the Faroe Islands. Economic incentives influence ecological restoration and depend on laws and policies in each country. Our analyses suggest that habitat types determine the methods of ecological restoration, whereas socio-economic drivers are more important for the decisions concerning the timing and location of restoration. To improve the understanding, planning, and implementation of ecological restoration, we advocate increased cooperation and knowledge sharing across disciplines and among countries, both in the Nordic countries and internationally. An obvious advantage of such cooperation is that a wider range of experiences from different habitats and different socio-economic conditions becomes available and thus provides a more solid basis for developing practical solutions for restoration methods and policies.
... Degraded systems can be considered when a strong driver has changed the system to such an extent that the system has lost function, diversity or structure (Aradóttir & Arnalds 2001; Hüttl & Schneider 1998). Driver changes are often human induced (Aradóttir & Arnalds 2001). ...
... Degraded systems can be considered when a strong driver has changed the system to such an extent that the system has lost function, diversity or structure (Aradóttir & Arnalds 2001; Hüttl & Schneider 1998). Driver changes are often human induced (Aradóttir & Arnalds 2001). Subsequent restoration involves human activities directed at instituting a set of processes to guide the system towards the range of acceptable ecosystem states (Society for Ecological Restoration 2004). ...
Article
Full-text available
Diverse political, cultural and biological needs epitomise the contrasting demands impacting on the mandate of the South African National Parks (SANParks) to maintain biological diversity. Systems-based approaches and strategic adaptive management (learn by doing) enable SANParks to accommodate these demands. However, such a management strategy creates new information needs, which require an appropriate analytical approach. We use conceptual links between objectives, indicators, mechanisms and modulators to identify key concerns in the context of and related to management objectives. Although our suggested monitoring designs are based mostly on defined or predicted underlying mechanisms of a concern, SANParks requires inventory monitoring to evaluate its key mandate. We therefore propose a predictive inventory approach based on species assemblages related to habitat preferences. Inventories alone may not always adequately serve unpacking of mechanisms: in some cases population size needs to be estimated to meet the information needs of management strategies, but actual population sizes may indirectly affect how the species impact on other values. In addition, ecosystem objectives require multivariate assessments of key communities, which can be used in trend analysis. SANParks therefore needs to know how to detect and define trends efficiently, which, in turn, requires precision of measures of variables.
... Degradation reduced the amount of viable land in communal grazing areas, and livestock would have needed to be relocated to suitable rangeland sites at lower altitudes (such as Kalmanstj€ orn). The increase in livestock populations would have damaged Betula seedlings, preventing the replacement of lost trees (Gill 1992;Arad ottir & Arnalds 2001). Compounding this, the cooler temperatures slowed the growth of those seedlings that survived, further slowing the replenishment of woodland stocks (Wastl et al. 2001;Weih & Karlsson 2001). ...
Article
Full-text available
The settlement of Iceland is known to have had profound impacts on vegetation and landscape stability, but there remain uncertainties around the spatial variability and timing of environmental change, and the impacts of settlement on aquatic ecosystems. Here a new multiproxy palaeoenvironmental reconstruction spanning the last 3000 years is presented from Kalmanstjörn, a small lake in Mývatnssveit, northeast Iceland. Sedimentology, pollen and non‐pollen palynomorphs, and geochemical proxies, dated using tephrochronology, are used to reconstruct terrestrial vegetation, landscape stability and aquatic ecosystems. The data reveal complex environmental dynamics after settlement. At this site, substantial tree populations persisted until the late 15th century, in strong contrast to the rapid deforestation shown by almost all other records from Iceland. The eventual loss of woodland may have been caused by changes in direct human activity and the location of extensive grazing, in combination with Little Ice Age climatic cooling. The loss of woodland was accompanied by increased soil erosion. Conversely, the lake ecosystem showed an immediate response to settlement, becoming more productive for several centuries, perhaps in response to increased availability of nutrients from grazing herbivores. The late persistence of woodland in the Kalmanstjörn record adds to our understanding of the spatial variations in ecosystem responses to settlement in Iceland, while the evidence for decoupling of the aquatic and terrestrial systems suggests that palaeolimnological reconstructions focusing on aquatic ecosystem responses may be important new sources of information on the wider ecological consequences of human settlement.
... In a controlled environment, St. Clair et al. (1984) observed that the establishment of three grass species was higher in an undisturbed mixed biocrust than in a trampled one. On eroded areas in Iceland, higher seedling densities and reduced seedling mortality of several species were observed in microsites with biocrusts compared to sparsely biocrusted ones; these effects have been attributed to less soil erosion and frost heaving in the more biocrusted microsites (Aradottir and Arnalds 2001;Karlsdottir and Aradottir 2006). Biocrust effects on seedling survival and growth can also vary according to both biocrust type and plant species. ...
Chapter
Full-text available
Biocrusts and vascular plants interact on many levels. The nature and consequences of these interactions vary with biocrust and plant characteristics and environmental conditions and throughout the plants’ life cycle. Biocrust structure and surface texture—shaped by its species composition and the environment—interacting with seed shape and size, determine whether the crust facilitates or deters seed capture and thus seedling establishment. In general, biocrusts tend to enhance plant growth through improved availability of nutrients, but root architecture plays a role in determining the effect of crusts on nutrient uptake. Furthermore, exchange of nutrients between biocrusts and vascular plants can occur through different pathways, including fungal linkages. Vascular plant communities also affect biocrust development, composition, and function through canopy shading, litterfall, and root activity and their effects on microclimate. The vascular plant canopy tends to favor certain biocrust species groups over others and usually enhances biocrust formation; however, a dense canopy can deprive crusts of adequate light for photosynthesis. Likewise, light litterfall may protect or favor biocrusts by improving the microclimatic conditions, while heavy litterfall can bury, damage, or destroy the crusts.
... More than 37,000 km 2 are barren deserts, some of which have formed after settlement (874 AD). The vegetation composition of rangelands reects sheep grazing, with species tolerant to grazing dominating most communities, such as small woody species and sedges (see e.g., Aradóttir and Arnalds, 2001). Birch woodlands used to cover a large proportion of the country (25–40%, see Aradóttir and Eysteinsson, 2005) but now only comprise about 1% due to land degradation processes (Aradóttir and Arnalds , 2001; Aradóttir and Eysteinsson, 2005). ...
Chapter
Cyanobacterial soil crusts (CSCs) are unique microhabitats in desert soil plays a significant role in stabilization of soil surface and provide favourable conditions for the establishment of vascular plants. The CSCs types and its distribution mainly depend up on the locality and climatic factors of the region. They help in retaining soil particles, nutrients, moisture and also add up carbon and nitrogen to the nutrient poor soils. The natural or anthropogenic intervention exerted immense pressure on the crusts community and diversity; leads to disturbed or distressed CSCs. Currently military use of the deserts have destroyed the fragile ecology of these CSCs and delay the time of recovery to reach functional state. To stabilize and rehabilitate the disturbed CSCs, a number of strategies successfully tested and implemented in small scale, some of them are artificial stabilization, resource augmentation and cyanobacterial inoculants. Biochar coupled rehabilitation of CSCs could be effective and sustainable approach for the stabilization of desert soils. Small scale biochar production would be helpful not only reducing the cost of rehabilitation but also help in providing livelihood to the local people.
Article
Vegetation exerts strong controls on fluvial sinuosity, providing bank stability and buffering surface runoff. These controls are manifest in densely vegetated landscapes, whereas sparsely vegetated fluvial systems have been so far overlooked. This study integrates remote sensing and gauging records of the meandering to wandering Fossálar River, a relatively steep-sloped (< 2.5%) Icelandic river featuring well-developed point bars (79%–85% of total active bar surface) despite the lack of thick, arborescent vegetation. Over four decades, fluctuations in the sinuosity index (1.15–1.43) and vegetation cover (63%–83%) are not significantly correlated (r = 0.28, p > 0.05), suggesting that relationships between the two are mediated by intervening variables and uncertain lag times. By comparison, discharge regime and fluvial planform show direct correlation over monthly to yearly time scales, with stable discharge stages accompanying the accretion of meander bends and peak floods related to destructive point-bar reworking. Rapid planform change is aided by the unconsolidated nature of unrooted alluvial banks, with recorded rates of lateral channel-belt migration averaging 18 m/yr. Valley confinement and channel mobility also control the geometry and evolution of individual point bars, with the highest degree of spatial geomorphic variability recorded in low-gradient stretches where lateral migration is unimpeded. Point bars in the Fossálar River display morphometric values comparable to those of other sparsely vegetated rivers, suggesting shared scalar properties in sparsely vegetated fluvial landscapes. This conjecture prompts the need for more sophisticated integrations between remote sensing and gauging records on modern rivers lacking widespread plant life. While a large volume of experimental and field-based work maintains that thick vegetation has a critical role in limiting braiding, thus favouring sinuosity, this study demonstrates the stronger controls of discharge regime and alluvial morphology on sparsely vegetated sinuous rivers.
Chapter
The Icelandic National Forest Inventory was initiated in 2001 (Snorrason and Kjartansson in Skógræktarritið 101–108, 2004). After four years of preparation, data sampling on field plots started in the spring of 2005. While the data sampled is used to produce valuable information for many purposes, the primary reason for starting National Forest Inventory (NFI) was the need for reliable annual data to report to the United Nation Framework Convention on Climate Change (UNFCCC).
Chapter
This chapter presents the results of the Agricultural University of Iceland vegetation classification, which is based on separating the vegetation into 10 classes. Iceland has the poorest vegetation cover of all countries in Europe, less than 45 %. Heathlands, especially poor heathland (25,000 km2) is the most abundant vegetation, wetlands comprise about 8,000 km2, but deserts of various kinds >40,000 km2. The heathlands reflect the long-lasting grazing of these systems. The wetlands are in many ways a unique blend of aquic, Arctic, and andic soil systems and are especially important ecosystems. Most of the lowland wetlands have been drained for agricultural purposes. Biological soil crusts are essential components of many of Icelandic ecosystems. Icelandic deserts are the largest volcaniclastic deserts on Earth. These soil surfaces are variable but many desert soils dry out easily in spite of ample rainfall in many parts. The deserts shed new light on such terms as ‘desert’ and ‘desertification’. Introduced invasive species are of concern for Icelandic nature.
ResearchGate has not been able to resolve any references for this publication.