Amanda Thomson

Land cover change in Europe between 1950 and 2000 determined employing aerial photography.

BIOPRESS (‘Linking Pan-European Land Cover Change to Pressures on Biodiversity’), a European Commission funded ‘Global Monitoring for Environment and Security’ project, produced land cover change information (1950—2000) for Europe from aerial photographs and tested the suitability of this for monitoring habitats and biodiversity. The methods and results related to the land cover change work are summarized. Changes in land cover were established through 73 window and 59 transect samples distributed across Europe. Although the sample size was too small and biased to fully represent the spatial variability observed in Europe, the work highlighted the importance of method consistency, the choice of nomenclature and spatial scale. The results suggest different processes are taking place in different parts of Europe: the Boreal and Alpine regions are dominated by forest management; abandonment and intensification are mainly encountered in the Mediterranean; urbanization and drainage are more characteristic of the Continental and Atlantic regions.

Crossing the thresholds: human ecology and historical patterns of landscape degradation

Abstract In discussions of landscape sensitivity, human activities have generally been regarded as external forces contributing to landscape change, with a focus on the impacts of cultivation methods, fertiliser practices, grazing pressures and atmospheric pollution. However, there has been comparatively little study undertaken that integrates physical and social systems in a historic context to explain the basis of human activity in sensitive landscapes. Where such attempts have been made, the manner of common land management has figured prominently, with ‘tragedy of the commons’ concepts used to explain land degradation and to provide a foundation for policy response. This has also been the case in Southern Iceland and in this paper we assess the extent to which common land domestic grazing pressures were the primary external force causing soil erosion and land degradation during the period of occupation from ca. 874 AD. We first provide field observation of soil erosion, temporally defined by tephrochronology, to highlight the extent of land degradation during this period. The ‘tragedy of the commons’ explanation of degradation is then assessed by evaluating historic documentary sources, and by environmental reconstruction and modeling of historic grazing pressures. These analyses indicate that regulatory mechanisms were in place to prevent overgrazing from at least the 1200s AD and suggest that there was sufficient biomass to support the numbers of domestic livestock indicated from historic sources. We suggest that failure to remove domestic livestock before the end of the growing season and an absence of shepherding were more likely to contribute to land degradation than absolute numbers. Lack of appropriate regulation of domestic livestock on common grazing areas can be attributed to limited cultural knowledge of changing and rapidly fluctuating environmental conditions.

REVIEW: The role of ecosystems and their management in regulating climate, and soil, water and air quality

1. Ecosystems have a critical role in regulating climate, and soil, water and air quality, but management to change an ecosystem process in support of one regulating ecosystem service can either provide co-benefits to other services or can result in trade-offs. 2. We examine the role of ecosystems in delivering these regulating ecosystem services, using the UK as our case study region. We identify some of the main co-benefits and trade-offs of ecosystem management within, and across, the regulating services of climate regulation, and soil, water and air quality regulation, and where relevant, we also describe interactions with other ecosystem services. Our analysis clearly identifies the many important linkages between these different ecosystem services. 3. However, soil, water and air quality regulation are often governed by different legislation or are under the jurisdiction of different regulators, which can make optimal management difficult to identify and to implement. Policies and legislation addressing air, water and soil are sometimes disconnected, with no integrated overview of how these policies interact. This can lead to conflicting messages regarding the use and management of soil, water and air. Similarly, climate change legislation is separate from that aiming to protect and enhance soil, water and air quality, leading to further potential for policy conflict. 4. All regulating services, even if they are synergistic, may trade off against other ecosystem services. At a policy level, this may well be the biggest conflict. The fact that even individual regulating services comprise multiple and contrasting indicators (e.g. the various components of water quality such as nutrient levels, acidity, pathogens and sediments), adds to the complexity of the challenge. 5. Synthesis and applications. We conclude that although there are some good examples of integrated ecosystem management, some aspects of ecosystem management could be better coordinated to deliver multiple ecosystem services, and that an ecosystem services framework to assess co-benefits and trade-offs would help regulators, policy-makers and ecosystem managers to deliver more coherent ecosystem management strategies. In this way, an ecosystem services framework may improve the regulation of climate, and soil, water and air quality, even in the absence of economic valuation of the individual services.

Stream water hydrochemistry as an indicator of carbon flow paths in Finnish peatland catchments during a spring snowmelt event

Extreme hydrological events are known to contribute significantly to total annual carbon export, the largest of which in Arctic and boreal catchments is spring snowmelt. Whilst previous work has quantified the export of carbon during snowmelt, the source of the carbon remains unclear. Here we use cation hydrochemistry to trace the primary flowpaths which govern the export of carbon during the snowmelt period; specifically we aim to examine the importance of snowpack meltwater to catchment carbon export. The study was carried out in two forested peatland (drained and undrained) catchments in Eastern Finland. Both catchments were characterised by base-poor stream water chemistry, with cation concentrations generally decreasing in response to increasing discharge. Streamflow during the snowmelt period was best described as a mixture of three sources: pre-event water, snowpack meltwater and a third dilute component we attribute to the upper snow layer which was chemically similar to recent precipitation. Over the study period, pre-event water contributed 32% and 43% of the total stream runoff in Välipuro (undrained) and Suopuro (drained), respectively. The results also suggest a greater near-surface throughflow component in Suopuro, the drained catchment, prior to snowmelt. CO(2) and DOC concentrations correlated positively with cation concentrations in both catchments indicating a common, peat/groundwater flowpath. CH(4) concentrations were significantly higher in the drained catchment and appeared to be transported in near-surface throughflow. Meltwater from the snowpack represented an important source of stream water CO(2) in both catchments, contributing up to 49% of total downstream CO(2) export during the study period. We conclude that the snowpack represents a potentially important, and often overlooked, transient carbon store in boreal snow-covered catchments.

A grazing model for simulating the impact of historical land management decisions in sensitive landscapes: Model design and validation

Abstract This paper reports the construction and testing of a historical environmental simulation model, Bumodel ( bu : Icelandic – farm estate or enterprise). The model permits the investigation of historical grazing management under variable environmental conditions in Iceland through the prediction of spatial and temporal patterns of vegetation biomass and utilisation. Input parameters of the model are environmental, livestock and management variables from historical and archaeological sources. Process sub-models were constructed using contemporary Icelandic data. Validation of the model was based on an independent, published grazing experiment and demonstrated that Bumodel-predicted utilisable biomass values and biomass intake values fall within ±1 standard deviation of observed values. Bumodel provides a validated representation of linkages between environmental and management elements in a historical grazing system. It incorporates key issues of spatial and temporal scale, data quality, model validation and the inherent stochasticity of landscape change over historical periods. In doing so, it enables researchers interested in past landscapes to investigate the flexibility of the historical Icelandic grazing systems within the constraints of climate and vegetation cover, and provides a framework and methodology that can be applied to other historical extensive livestock-based agricultural systems. Access to the model is available at http://www.sbes.stir.ac.uk/research/environmental_modelling/ .

Land in Landscapes Circum Landnám: An Integrated Study of Settlements in Reykholtsdalur, Iceland

ABSTRACT The initial settlement of Iceland in the 9th and 10th centuries AD was based on animal husbandry, with an emphasis on dairy cattle and sheep. For this activity, land resources that offered a range of grazing and fodder production opportunities were required to sustain farmsteads. In this paper, the nature of land within the boundaries of settlements in an area of Western Iceland centered on Reykholt, which became the estate of the writer and chieftain Snorri Sturluson in the 13th century, is analysed with a geographical information systems (GIS) approach. The results, combining historical, archaeological, and environmental data with the GIS-based topographic analysis, suggests that, although inherent land qualities seem to have played a part in shaping the initial hierarchy of settlement in the area, it was the acquisition of additional property and of access to resources outside the valley that ultimately pushed Reykholt to the forefront in the hierarchical order.

Quantifying gross vs. net agricultural land use change in Great Britain using the Integrated Administration and Control System

Land use change has impacts upon many natural processes, and is one of the key measures of anthropogenic disturbance on ecosystems. Agricultural land covers 70% of Great Britains (GB) land surface and annually undergoes disturbance and change through farming practices such as crop rotation, ploughing and the planting and subsequent logging of forestry. It is important to quantify how much of GBs agricultural land undergoes such changes and what those changes are at an annual temporal resolution. Integrated Administration and Control System (IACS) data give annual snapshots of agricultural land use at the field level, allowing for high resolution spatiotemporal land use change studies at the national scale. Crucially, not only do the data allow for simple net change studies (total area change of a land use, in a specific areal unit) but also for gross change calculations (summation of all changes to and from a land use), meaning that both gains and losses to and from each land use category can be defined. In this study we analysed IACS data for GB from 2005 to 2013, and quantified gross change for over 90% of the agricultural area in GB for the first time. It was found that gross change totalled 63,500 km2 in GB compared to 20,600 km2 of net change, i.e. the real year-on-year change is, on average, three times larger than net change. This detailed information on nature of land use change allows for increased accuracy in modelling the impact of land use change on ecosystem processes and is directly applicable across EU member states, where collection of such survey data is a requirement. The modelled carbon flux associated with gross land use change was at times >100 Gg C y-1 larger than that based on net land use change for some land use transitions.