Biotope monitoring

The biotope monitoring unit primarily works with environmental monitoring and assessment. Many of our projects are assignments from other authorities, such as the Board of Agriculture, Environmental Protection Agency and several county administrative boards.

Methods and design for habitat and landscape monitoring

Our work focuses on developing clear definitions, methods and criteria for mapping and estimating the conservation status, natural value and changes over time of open, terrestrial habitats. This will provide data and results for Sweden’s reporting under the EU’s Habitat Directive.

The same data collection methods can also be used to analyse landscape composition, the influence of land use and the occurrence of habitats for species. The data collection is designed to provide a representative view, in an ecological and societal context to ensure the results are relevant and useful. As environmental conditions vary between regions, a good understanding of how the ecological systems work is required. 

Our work also involves providing reference data on common types of agricultural land and wetlands, as well as highlighting and improving the knowledge of uncommon or poorly documented habitats, including their ecological properties, landscape context and changes over time.

Mapping of land types and habitats using aerial photo interpretation

Mapping of habitats and land types using high-resolution aerial photographs, purchased yearly from the Swedish Mapping, Cadastral and Land Registration Authority (Lantmäteriet), is a central tool for describing the landscape and conducting quantitative analyses. We use false-colour infrared aerial photographs, which make it possible to distinguish more effectively between vegetation types and ground characteristics more effectively, for example coniferous/broad-leaved trees or soil wetness.

The aerial photos are taken with some overlap to allow for visual stereoviewing, which gives information about topographical variation, height and slope. Thanks to the frequent photo intervals, changes in the landscape can be traced over time, in our case mostly with six-year intervals. Direct comparison of photos from different time periods is useful for detailed analysis of small changes, landscape variation, and spatial relations between objects.

Field inventory of plants, vegetation and landscape elements

To investigate grasslands, wetlands and other habitats, we use circular plots with permanent coordinates. These plots are revisited regularly (usually every six years) to monitor changes in vegetation structure, plant species content and human impact. The plant community acts as an indicator of environmental conditions and land use influence.

To complement the information of the landscape, specific methods are used to map landscape elements and small biotopes that are not well described through large-scale mapping. Examples include ditches, stone walls, mid-field islets, forest edges, solitary trees and flowering shrubs. 

Analysis methods and indicator development for environmental assessment

Environmental monitoring and assessment face several challenges. One important limitation is that statistical estimations and correlations do not always explain what a favourable state or the cause behind the observed patterns is. Large-scale samples therefore need to be combined with knowledge about local conditions and ecological understanding. Model-based analyses that consider the interaction between environmental factors and impact factors are required to interpret the monitoring results.

Society requires clear and transparent environmental indicators, but there is a lack of indicators for the agricultural landscape that both capture important environmental effects and provide guidance on ways to improveme. Another challenge is that many landscape changes occur irregularly over time and space, meaning that traditional sample-based monitoring is often too slow and generalised to capture harmful changes in time.  Therefore, we are developing methods to better distinguish real changes from natural variation, coincidences, or uncertainties in measurements.