Biomedical subjects

Per Angelstam

Publications and source records attributed to Per Angelstam.

5 recordsLinked to original sources

PubMed2004

The dynamics of ecosystems, biodiversity management and social institutions at high northern latitudes.

Ecosystems at high latitudes are highly dynamic, influenced by a multitude of large-scale disturbances. Due to global change processes these systems may be expected to be particularly vulnerable, affecting the sustained production of renewable wood resources and abundance of plants and animals on which local cultures depend. In this paper, we assess the implications of new understandings of high northern latitude ecosystems and what must be done to manage systems for resilience. We suggest that the focus of land management should shift from recovery from local disturbance to sustaining ecosystem functions in the face of change and disruption. The role of biodiversity as insurance for allowing a system to reorganize and develop during the disturbance and reorganization phases needs to be addressed in management and policy. We emphasize that the current concepts of ecological reserves and protected areas need to be reconsidered to developp dynamic tools for sustainable management of ecosystems in face of change. Characteristics of what may be considered as customary reserves at high latitudes are often consistent with a more dynamic view of reserves. We suggest new directions for addressing biodiversity management in dynamic landscapes at high latitudes, and provide empirical examples of insights from unconventional perspectives that may help improve the potential for sustainable management of biodiversity and the generation of ecosystem services.

Animals↗

PubMed2003

Reserves, resilience and dynamic landscapes.

In a world increasingly modified by human activities, the conservation of biodiversity is essential as insurance to maintain resilient ecosystems and ensure a sustainable flow of ecosystem goods and services to society. However, existing reserves and national parks are unlikely to incorporate the long-term and large-scale dynamics of ecosystems. Hence, conservation strategies have to actively incorporate the large areas of land that are managed for human use. For ecosystems to reorganize after large-scale natural and human-induced disturbances, spatial resilience in the form of ecological memory is a prerequisite. The ecological memory is composed of the species, interactions and structures that make ecosystem reorganization possible, and its components may be found within disturbed patches as well in the surrounding landscape. Present static reserves should be complemented with dynamic reserves, such as ecological fallows and dynamic successional reserves, that are part of ecosystem management mimicking natural disturbance regimes at the landscape level.

Animals↗

PubMed2003

Distribution of deciduous stands in villages located in coniferous forest landscapes in Sweden.

Termination of fire along with active removal of deciduous trees in favor of conifers together with anthropogenic transformation of productive forest into agricultural land, have transformed northern European coniferous forests and reduced their deciduous component. Locally, however, in the villages, deciduous trees and stands were maintained, and have more recently regenerated on abandoned agricultural land. We hypothesize that the present distribution of the deciduous component is related to the village in-field/out-field zonation in different regions, which emerges from physical conditions and recent economic development expressed as land-use change. We analyzed the spatial distribution of deciduous stands in in-field and out-field zones of villages in 6 boreal/hemiboreal Swedish regions (Norrbotten, Angermanland, Jämtland, Dalarna, Bergslagen, Småland). In each region 6 individual quadrates 5 x 5 km centered on village areas were selected. We found significant regional differences in the deciduous component (DEC) in different village zones. At the scale of villages Angermanland had the highest mean proportion of DEC (17%) and Jämtland the lowest (2%). However, the amounts of the DEC varied systematically in in-field and out-field zones. DEC was highest in the in-field in the south (Småland), but generally low further north. By contrast, the amount of DEC in the out-field was highest in the north. The relative amount of DEC in the forest edge peaked in landscapes with the strongest decline in active agriculture (Angermanland, Dalarna, Bergslagen). Because former and present local villages are vital for biodiversity linked to the deciduous component, our results indicate a need for integrated management of deciduous forest within entire landscapes. This study shows that simplified satellite data are useful for estimating the spatial distribution of deciduous trees and stands at the landscape scale. However, for detailed studies better thematic resolution is needed to determine biologically relevant differences in quality of deciduous stands.

Environmental Monitoring↗

PubMed2003

Two-dimensional gap analysis: a tool for efficient conservation planning and biodiversity policy implementation.

The maintenance of biodiversity by securing representative and well-connected habitat networks in managed landscapes requires a wise combination of protection, management, and restoration of habitats at several scales. We suggest that the integration of natural and social sciences in the form of "Two-dimensional gap analysis" is an efficient tool for the implementation of biodiversity policies. The tool links biologically relevant "horizontal" ecological issues with "vertical" issues related to institutions and other societal issues. Using forest biodiversity as an example, we illustrate how one can combine ecological and institutional aspects of biodiversity conservation, thus facilitating environmentally sustainable regional development. In particular, we use regional gap analysis for identification of focal forest types, habitat modelling for ascertaining the functional connectivity of "green infrastructures", as tools for the horizontal gap analysis. For the vertical dimension we suggest how the social sciences can be used for assessing the success in the implementation of biodiversity policies in real landscapes by identifying institutional obstacles while implementing policies. We argue that this interdisciplinary approach could be applied in a whole range of other environments including other terrestrial biota and aquatic ecosystems where functional habitat connectivity, nonlinear response to habitat loss and a multitude of economic and social interests co-occur in the same landscape.

Conservation of Natural Resources↗

PubMed2003

Assessing village authenticity with satellite images: a method to identify intact cultural landscapes in Europe.

The village with its characteristic zones of different land use from the center to the periphery is a basic unit of Europe's cultural landscapes. However, loss of the authentic pre-industrial village structure characterized by a fine-grained structure of arable land and wooded grasslands is a threat to both cultural heritage and biodiversity in many rural landscapes. Therefore, it is important that the extent and rate of change of such authentic villages in a landscape can be monitored. We studied to what extent loss of authenticity with increasing time after abandonment can be assessed by quantitative analysis and visual interpretation of satellite images. The study was carried out in the Bieszczady Mountains, SE Poland in 1999. Using Landsat Thematic Mapper data from 1998, both the grain size of landscape elements (size of fields) and land-cover composition (encroachment of shrub and forest) were quantitatively described 6 type villages representing different stages of deterioration of the authentic village structure. Historical maps were used to delineate the border of the villages and the former extension of forest and open land was measured. The present land use and the degree of abandonment expressed as grain size and forest encroachment were mapped using satellite data. Deterioration occurred along 2 transformation paths: abandonment and ultimately becoming forest, or intensified agriculture, respectively. To validate these results we classified 22 other villages in a 1000 km2 area by visual interpretation of the original satellite images into 1 of 4 types. We then collected historical data on human population changes over the past six decades. The classification of village authenticity was clearly related to the rate of human population decline. We address the importance of validating and applying this approach for rapid assessment of the authenticity of cultural landscapes in European regions being subject to ongoing as well as expected future change, related to expansion of the European Union. Finally, we argue that the village represents a scale at which integration of natural and social sciences is possible.

Agriculture↗