Epsilon Archive for Student Projects

Abstract

Semi-natural grasslands in Sweden are disappearing due to changes in land use and agricultural practices. With this there is also a loss of species that are dependent on these habitats for their survival. One way to try to combat this decline is through the restoration of grasslands that have been abandoned. In this paper 37 different semi-natural grasslands and the vascular plant within them were revisited and surveyed, and compared with the diversity and species composition 14 years earlier. The survey was done in 10 randomized spots in each grassland, and a 1 by 1 meter square was surveyed at each point. Analysis was run on the resulting species richness, frequency, Shannon diversity. Values similar to Ellenberg values for Swedish species calculated by Tyler et al. (2021) was used for the species temperature niches, grazing needs and light needs. Classification of generalist, narrow and broad specialists came from Öckinger et al. (2012) to analyses the change of these over time. Majority of analysis consisted of GLMM analysis using the grasslands as a grouped value to decrease the risk of false significances. The analyses made in this survey yielded differing results where most of them were non-significant, such as most of the analyzed Ellenberg equivalent values and the cover of both generalists and specialists. This can be seen in the GLMM analyses. This can have a variety of reasons which are discussed later in this paper. The significant results on the other hand were a decline in species abundance for both restored, continuously grazed and abandoned grasslands, and an increase in narrow specialist species in continuous and restored grasslands. It is likely that the lack of significant results is partly because of the timing of this survey. The time since restoration might fall outside of the optimal frame for restoration and it had been restored for a while even before the first survey in 2011. The restored grasslands show some more similarities with continuous grasslands which might mean that they are improving. Restored and abandoned grasslands on the other hand had also become more similar in some analysed categories such as grazing optimal values and light optimal values. Indications for an increase in narrow specialist species with time since restoration can be found when analysing both the 2011 and 2025 survey points using time since restoration for all points Results indicate that improvement might be happening, but many results are insignificant and more survey of the grasslands might be needed for a better analysis of the change over time.