A survey of habitats on agricultural land in Estonia: I Construction and validation of the database using the botanical field data

Abstract The project was initiated to model the species change in agricultural land under different scenarios in Estonia. This paper describes the first stages of the work. Thirty-five 1-km squares were selected for a survey using a dispersed random procedure within the eight classes of the Environmental Stratification of Estonia, which were weighted according to the number of 1-km squares. In each 1-km square, up to 11 vegetation plots were recorded using predetermined rules in three habitats where succession was taking place, four habitats that were potential sources of seed, and four habitats with linear features. Linear features had between 141 and 178 species present and were a major contribution to the biodiversity resources on agricultural land. Full lists of vascular plants were recorded, and the details of the methods that were used to locate the plots are provided. All the habitats over 400 m2 were also mapped using the General Habitat Categories, which are consistent throughout Europe. The field survey was performed from 2015 to 2017 in 35 1-km squares. Overall, 433 species were recorded, which covers 42% of the Estonian flora, as presented in the new Atlas. Interpretation of the frequency and cover of the different types of plots provides details of the structure and the composition of the current Estonian land and shows that there are still significant biodiversity resources in agricultural land − for both species and vegetation. Neglected and abandoned land were in 21 and 23 of the 35 squares, respectively, but the former land had 5% cover in only one stratum. Abandoned land was over 14% in the Southern Uplands, but only 10% in the Northern Lowlands. Crops varied from 2% to 53% cover, whereas forest cover was always above 25% and reached 55% in one stratum.