Climate warming and land-use changes drive broad-scale floristic changes in Southern Sweden

• Land-use changes, pollution and climate warming during the 20th century havecaused changes in biodiversity across the world. However, in many cases, the environmental drivers are poorly understood. To identify and rank the drivers currentlycausing broad-scale floristic changes in N Europe, we analysed data from two vascularplant surveys of 200 randomly selected 2.5 9 2.5 km grid-squares in Scania,southernmost Sweden, conducted 1989–2006 and 2008–2015, respectively, andrelated the change in frequency (performance) of the species to a wide range ofspecies-specific plant traits. We chose traits representing all plausible drivers ofrecent floristic changes: climatic change (northern distribution limit, flowering time),land-use change (light requirement, response to grazing/mowing, response to soildisturbance), drainage (water requirement), acidification (pH optimum), nitrogendeposition and eutrophication (N requirement, N fixation ability, carnivory, parasitism,mycorrhizal associations), pollinator decline (mode of reproduction) andchanges in CO2 levels (photosynthetic pathway). Our results suggest that climatewarming and changes in land-use were the main drivers of changes in the flora duringthe last decades. Climate warming appeared as the most influential driver, withnorthern distribution limit explaining 30%–60% of the variance in the GLMM models.However, the relative importance of the drivers differed among habitat types,with grassland species being affected the most by cessation of grazing/mowing andspecies of ruderal habitats by on-going concentration of both agriculture and humanpopulation to the most productive soils. For wetland species, only pH optimum wassignificantly related to species performance, possibly an effect of the increasinghumification of acidic water bodies. An observed relative decline of mycorrhizal species may possibly be explained by decreasing nitrogen deposition resulting in lesscompetition for phosphorus. We found no effect of shortage or decline of pollinatinglepidopterans and bees.

Ämnesord

NATURVETENSKAP  -- Biologi -- Botanik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Botany (hsv//eng)

LANTBRUKSVETENSKAPER  -- Annan lantbruksvetenskap -- Miljö- och naturvårdsvetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Other Agricultural Sciences -- Environmental Sciences related to Agriculture and Land-use (hsv//eng)

Nyckelord

bee decline, citizen science, grazing, humification, mycorrhiza, nitrogen deposition, phenology, plant traits

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)