Landscape ecology and pond quality – studies of frogs by field experiments in the agricultural landscape
Jon Loman (project leader)
Summary of results from Department of Ecology, Lund University.
Give frogs a chance
In heavily cultivated farming landscapes frogs are quite uncommon. The common frog is scarce in ponds surrounded by arable land, and, despite its name, the common frog is extremely hard to find. What is the reason for this? What is it that limits species in this landscape?
The study indicates that shortcomings in the terrestrial environment limit their dispersion. The study cannot provide an answer to what it is that is lacking, but it may be suspected that cultivated fields provide poor protection and also have few prey animals. During large parts of the year, the microclimate also is perhaps too dry. On the other hand, access to places for hibernation should not be a limiting factor. Frogs can hibernate in ponds, provided that there is no shortage of oxygen, and there is often access to flowing water in open ditches. Obviously, in some areas the shortage of ponds may be a more serious problem than their quality.
Better conditions can be created for frogs in farming landscapes if cultivation of wet areas is avoided. Wide zones around ponds can also be left untouched, and measures can be taken to ensure that they are not neglected or used as dumping grounds for organic materials. The spatial relationship between ponds and good terrestrial environments governs the chances of frogs to connect up different landscape elements through annual migrations.
Development of shores in the Stockholm archipelago – effects on biodiversity
Lenn Jerling (project leader)
Summary of results with list of publications from Department of Botany, Stockholm University.
Email: lenn.jerling@botan.su.se
A number of factors affect the species richness and species composition of plants on our shores. Both abiotic and biotic factors in the surroundings have an effect. The aim of this study has been to find which factors are the most important.
Marine influences on terrestrial food webs – The importance of chironomidae and algal drift walls
Peter Hambäck (project leader)
Summary of results with list of publications from Stockholm University.
Email: peter.hamback@botan.su.se
Coasts are unique natural areas characterised by an interplay between sea and land. They are also areas that are threatened by human development in the form of holiday houses, marinas and other recreational activities. Understanding of the ecological processes in these areas is therefore essential for nature conservancy and species conservation. While the flow from land to water, chiefly in the form of nutrients, is well known, the flow from water to land has received relatively little study.
In this project a study was made of the flow from sea to land of algae and chironomidae, and the way this affects invertebrates in the coastal zone. The conclusion is that the coastal zone must be seen as one system in both water and on land. To enhance understanding of ecological processes in these areas, it is essential to use an approach that involves more active collaboration between marine and terrestrial ecologists.
Prediction of the extinction risk of threatened wood-living insects in dynamic landscapes
Thomas Ranius (project leader)
Summary of results with list of publications from SLU.
Email: thomas.ranius@ekol.slu.se
Since it is difficult and time consuming to perform long term experiments, simulations are essential for an understanding of how various processes affect biodiversity over larger temporal and spatial scales. The dynamics and extinction risk of populations are affected by their demography, the quality and distribution of the habitat, as a result of natural processes or human activity. Ecologists combine two types of simulation models to predict these processes: landscape models and metapopulation models. Landscape models predict how habitats change over time, while metapopulation models predict how a species colonises and dies out from different parts of the landscape.
Many wood-living insects or cryptogams are threatened, since the quantity of dead wood is much lower in managed than virgin forests. It is only for some single species of these that we have knowledge of their colonising capacity, population size and occurrence pattern at landscape level. It has therefore been difficult to predict what requirements wood-living insects have to survive in the long term. The objective of this project was to construct the first models for the local extinctions and colonisation of wood-living species in landscapes that change over time. They are also useful in evaluating the long term effect of nature conservancy measures.
Information on the environmental effects of forestry to civil servants in municipalities, county administrative boards and water authorities
Malin von Essen (project leader)
Summary of results with list of publications from Forestry Research Institute of Sweden.
Email: malin.vonessen@skogforsk.se
The objective of the project was to provide access to present knowledge of the environmental effects of forestry measures. The fundamental premise was that knowledge is essential for a constructive dialogue between forestry and authorities. The focus of the project was on the abiotic effects of forestry on land and water, but through collaboration with researchers at SLU the biological effects were also highlighted.
Responsible for this page: Kerstin Franklin