Sara Cousins, Professor at the Department of Physical Geography explains: “Researchers have often wondered where in the pre-historic European landscape one could find the grassland plants that we know today. Was it on floodplains, the grazing lands of wild animals or in the aftermath of forest fires? Now we can see that land uplift has provided huge areas of naturally-open land that rises up again after being pressed down during the last Ice Age, and that this can be one of the sources of grassland species before the introduction of livestock grazing and haymaking”.

New grassland can save red-listed species

Snake’s head fritillary (Fritillaria meleagris) is one of the more exclusive plants that can be found on shore meadows in the study area. Photo: S. Cousins.

The new study uses a land uplift model over the Stockholm region to estimate how much potential coastal meadow has been created in this way during the past 4000 years. The team also counted plant species in present-day meadows and those that have been abandoned during the 20th century. Though they are few, small and isolated, the remaining coastal meadows are extremely important for the biodiversity of the whole landscape, especially for red-listed species. These threatened plants are in a perilous situation and appropriate meadow management is needed to avoid them disappearing from the landscape altogether.

The researchers estimate that during the past 4000 years, around 7900 km2 of new land has been created from land uplift in the region, of which around half could have been suitable for coastal meadow habitat. That’s an area the same size as the Swedish island of Gotland. During just the past 100 years, 80km2 of this potential meadow has emerged, compared to only 30 hectares of coastal meadow currently managed in the study region today.

Professor Cousins continues: “This is an especially exciting study, not only because we show just how much potential meadow has emerged, but also because we see how the age of the meadow dictates the species that we find, with many more different species of plants to be found as you walk further up the beach where the grasslands are older”.

The threat of overgrown areas and future sea-level rise are new challenges
 

Näset have some of the largest grazed shore meadows in the study area. The dominating part of grassland shown in the photo rose up from the sea during the last 100 years. Photo: S. Cousins.


The large areas of continuous meadow in the past where wild herbivores and grazing livestock could together create the right conditions for plants to thrive and disperse has meant that these grasslands are today especially valuable, and are protected by EU law. However, only a small fraction of coastal meadows in the region are currently grazed by livestock. The results of the new study are therefore not only important in showing the high diversity of remaining grasslands, but also because it is clear that the abandonment of meadows can quickly lead to overgrown areas and the disappearance of typical grassland species. The threat of future sea-level rise promises new challenges, and new grasslands will have to be created further inland to where the current species can move and establish.

Reference
Auffret, A.G., Cousins, S.A.O., 2018, Land uplift creates important meadow habitat and a potential original niche for grassland species, Proceedings of the Royal Society B: 20172349. http://dx.doi.org/10.1098/rspb.2017.2349