02; df = 1; p < 0.001 Bryophytes 24.1 (406) 34.4 (323) 5.6 (5)c χ2 = 141.60; df = 2; p < 0.001 Birds (red listed) 12.8 (67) 11.1 (44) 2.0 (1)d χ2 = 5.31; df = 2; p = 0.070 Birds (SPECs)e 43.1 (226) 38.0 (89) 22.0 (11) χ2 = 9.20; df = 2; p = 0.010 aThe functional groups of plants: PI plants listed in policy instruments, CWR crop wild relatives, AP aquatic plants bBased on local red list of vascular plants cBased on national red list of bryophytes dBased on list of birds threatened in Europe e SPEC species of European conservation concern Species of lower extinction risk The group of species placed into lower threat
categories contained ten bird species assessed as declining or depleted (equivalent of near threatened category) at the European
level, and 86 vascular plants. The plant species were HDAC inhibitor classified as being of least concern or near threatened in the local red list (10), and of least concern in the European red list, including 40 CWR, 38 aquatic species, and 2 species listed in PI (with Akt inhibitor several joint species, Online Resource 1). We did not record any bryophytes assigned to the lower threat categories. One bird species (the turtle dove Streptopelia turtur) was assessed as being of data deficient at the national level. Birds of conservation concern Eight of the eleven bird species of unfavorable conservation status were classed as SPEC 3 (9.7 % of breeding pairs) LY3039478 purchase and three as SPEC 2 (3.2 % of breeding pairs). Birds of conservation concern were noted in 95.7 % of study plots. The most numerous species was the Red-backed shrike
(Lanius collurio), which Amobarbital bred in 80 % of field margins, and was one of six dominants (>5 % pairs) in the bird community (Online Resource 1). Significance of vegetation structure The volume of trees and shrubs was positively correlated with species richness in each of the three taxonomic groups and the number of breeding pairs in birds (p < 0.001 in each of the Kendall’s tau correlations, Fig. 2A). The relationship between the volume of trees and shrubs and the number of TCCS was significant only with respect to the number of SPEC birds (Kendall’s tau = 0.246, p = 0.003, N = 70) and marginally significant with respect to the number of pairs of SPECs (Kendall’s tau = 0.154, p = 0.059, N = 70) and number of threatened bryophytes (Kendall’s tau = 0.146, p = 0.073, N = 70). These relationships imply that the increasing complexity of the vegetation structure led to an increase in total species richness, abundance of birds, and richness of SPECs. However, in percentage terms the occurrence of TCCS was nonlinearly related to the volume of trees and shrubs, with highest values recorded in the intermediate volume (Fig. 2B). Calculated separately in the three field margin types, the percentages of threatened vascular plants, bryophytes and birds of conservation concern tended to be higher in the shrubby margins (Table 4), but only the number of breeding pairs was significantly related.