“We knew previously that grassland has disappeared, but not to this extent. It is important to understand how this decline can affect biodiversity, as plants are usually very slow to respond to change. The wildflowers we see in the landscape today are often remnants of historical times, but this might not always be the case,” says Sara Cousins, professor at the Department of Physical Geography, Stockholm University, one of the researchers behind the study.
The new study shows that biodiversity at the landscape scale is actually strongly associated with how the landscape looks today. The ancient pastures and meadows which still exist are providing a vital home for many rare and specialised species, and must therefore be allowed to remain. On the other hand, a varied landscape can also provide valuable biodiversity by hosting a range of more common species in addition to the specialists.
“Our results indicate that many species which are specially adapted to the conditions present in unimproved ancient grasslands will have been lost following the disappearance of grasslands from the landscape. These pastures and meadows have been converted to arable land, planted with forest or quite simply abandoned,” says professor Sara Cousins.
It is of course well known that the modernisation of agriculture during the 19th and 20th centuries has resulted in the loss of many previously diverse landscapes. Previous studies have however only analysed changes in land use in relatively small landscapes. In the new study, the team used historical maps to analyse how the landscape has changed between 1901 and 2013 in an area covering 1642 km2, stretching through the rural countryside just south of Stockholm.
The digitalisation of the historical maps is extremely time consuming, and an analysis of this scale is unique in the field. Likewise, the collection of biodiversity data on such a scale is technically infeasible by researchers alone. For this reason, professor Cousins and colleagues were able to make use of existing data from the regional plant atlas, collected over several years by keen amateur botanists.
The study is published as part of a special issue of Ambio which focusses on the effects of climate and land-use change in the Swedish countryside. The article is open-access and can be downloaded for free. http://link.springer.com/article/10.1007/s13280-014-0585-9
The historical map data are being made available alongside the publication of the study. These data can be downloaded from the link above and explored with the help of geographical information system (GIS) software, such as the free QGIS. http://www.qgis.org/en/site/
For further information
Sara Cousins, Professor at the Department of Physical Geography, Stockholm University, phone +46(0)8-16 47 67, +46(0)708101595, email sara.cousins@natgeo.su.se
Alistair Auffret, researcher at the Department of Physical Geography, Stockholm University, phone +46(0)8-674 75 68, +46(0)767158975, email alistair.auffret@natgeo.su.se
Jessica Lindgren, PhD student at the Department of Physical Geography, Stockholm University, phone +46(0)8-674 7871, email jessica.lindgren@natgeo.su.se
