Trait-based analysis of decline in plant species ranges during the 20th century: a regional comparison between the UK and Estonia LAURI LAANISTO 1 , MAREK SAMMUL 2 , TIIU KULL 1 , PETR MACEK 3 and MICHAEL J. HUTCHINGS 4 1 Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51014 Tartu, Estonia, 2 Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia, 3 Faculty of Science, University of South Bohemia, Brani  sovsk a 31, 370 05  Cesk  e Bud ejovice, Czech Republic, 4 School of Life Sciences, University of Sussex, Falmer, Brighton, Sussex BN1 9QG, UK Abstract Although the distribution ranges and abundance of many plant species have declined dramatically in recent decades, detailed analysis of these changes and their cause have only become possible following the publication of second- and third-generation national distribution atlases. Decline can now be compared both between species and in differ- ent parts of species’ ranges. We extracted data from distribution atlases to compare range persistence of 736 plant species common to both the UK and Estonia between survey periods encompassing almost the same years (1969 and 1999 in the UK and 1970 and 2004 in Estonia). We determined which traits were most closely associated with varia- tion in species persistence, whether these were the same in each country, and the extent to which they explained dif- ferences in persistence between the countries. Mean range size declined less in Estonia than in the UK (24.3% vs. 30.3%). One-third of species in Estonia (239) maintained >90% of their distribution range compared with one-fifth (141) in the UK. In Estonia, 99 species lost >50% of their range compared with 127 species in the UK. Persistence was very positively related to original range in both countries. Major differences in species persistence between the stud- ied countries were primarily determined by biogeographic (affiliation to floristic element) and ecoevolutionary (plant strategy) factors. In contrast, within-country persistence was most strongly determined by tolerance of anthropogenic activities. Decline of species in the families Orchidaceae and Potamogetonaceae was significantly greater in the UK than in Estonia. Almost all of the 736 common and native European plant species in our study are currently declining in their range due to pressure from anthropogenic activities. Those species with low tolerance of human activity, with biotic pollination vectors and in the families referred to above are the most vulnerable, especially where human popu- lation density is high. Keywords: biodiversity loss, common species, comparative analysis, conservation, plant floras, traits, vegetation change Received 7 November 2014 and accepted 5 January 2015 Introduction Anthropogenic activities cause irreversible change to natural and semi-natural communities. It is well estab- lished that activities associated with the increasing den- sity of the human population have caused declines in the sizes of populations of many species, in localized species extinctions, and therefore in contractions in spe- cies ranges’, and in the establishment of invasive aliens (Drayton & Primack, 1996; Hooper et al., 2005; Kull & Hutchings, 2006; Isbell & Wilsey, 2011; Chown, 2012; Dullinger et al., 2013). Loss of biodiversity and of the ecosystem services and benefits provided by species is accelerating, potentially threatening the functional integrity of communities as a consequence of increasing anthropogenic impacts (Aguilar et al., 2006; Brook et al., 2008; Isbell et al., 2013). Factors causing declines in range and abundance include habitat loss and fragmentation. The smaller sizes and greater isolation of populations following such disruptions place them at greater risk of further decline and local extinction (Joshi et al., 2006; Laanisto et al., 2013). In addition, the impact of invasive species (Powell et al., 2011), the decrease in numbers, or total loss, of pollinating species (Aguilar et al., 2006; Albrecht et al., 2012) and other plant symbionts (Wagg et al., 2011), soil degradation (Verbruggen et al., 2010) and many other factors have been shown to be responsible for local extinctions of plant populations. Furthermore, changes in land use and climate have altered the loca- tions at which species can find both optimum and Correspondence: Lauri Laanisto, tel. +372 55636784, fax +372 731 3988, e-mail: laanisto@ut.ee 1 © 2015 John Wiley & Sons Ltd Global Change Biology (2015), doi: 10.1111/gcb.12887