TY - JOUR

T1 - Regional differences in soil pH niche among dry grassland plants in Eurasia

AU - Wagner, Viktoria

AU - Chytrý, Milan

AU - Zelený, David

AU - von Wehrden, Henrik

AU - Brinkert, Annika

AU - Danihelka, Jiří

AU - Hölzel, Norbert

AU - Jansen, Florian

AU - Kamp, Johannes

AU - Lustyk, Pavel

AU - Merunková, Kristina

AU - Palpurina, Salza

AU - Preislerová, Zdenka

AU - Wesche, Karsten

PY - 2017/5

Y1 - 2017/5

N2 - Soil pH is a key predictor of plant species occurrence owing to its effect on the availability of nutrients and phytotoxic metals. Although regional differences in realized soil pH niche ('niche shifts') have been reported since the 19th century, no study has disentangled how they are influenced by spatial differences in substrate availability, macroclimate, and competitors. We linked plot-level data on species occurrence and measured soil pH from dry grasslands in eight regions across Eurasia (n = 999 plots), spanning a geographic gradient of 6862 km. We calculated regional shifts in niche optimum (Dopt) and width (Dwidth) for 73 Species × Region 1 × Region 2 combinations (SRRs; 38 study species) using extended Huisman-Olff-Fresco models. Next, we used commonality analysis to partition the contribution of substrate availability, precipitation, and species traits indicative of competitive ability to variation in regional niche shifts. Shifts in optimum were rare (5% of SRRs with Dopt ≥ 1 pH units) but many species did not show optima within regions. By contrast, shifts in niche width were common (22% of SRRs with Dwidth ≥1 pH units) and there were pronounced interspecific differences. Whereas none of the three predictors significantly explained shifts in niche optimum, common and unique effects of substrate availability and precipitation accounted for 85% of variation in niche width. Our results suggest that substrate availability and precipitation could be the driving factors behind species regional shifts in niche width. Studies that address additional factors, such as other edaphic niches, and their variability at the regional and micro-scale will improve our understanding of the mechanisms underlying species distributions.

AB - Soil pH is a key predictor of plant species occurrence owing to its effect on the availability of nutrients and phytotoxic metals. Although regional differences in realized soil pH niche ('niche shifts') have been reported since the 19th century, no study has disentangled how they are influenced by spatial differences in substrate availability, macroclimate, and competitors. We linked plot-level data on species occurrence and measured soil pH from dry grasslands in eight regions across Eurasia (n = 999 plots), spanning a geographic gradient of 6862 km. We calculated regional shifts in niche optimum (Dopt) and width (Dwidth) for 73 Species × Region 1 × Region 2 combinations (SRRs; 38 study species) using extended Huisman-Olff-Fresco models. Next, we used commonality analysis to partition the contribution of substrate availability, precipitation, and species traits indicative of competitive ability to variation in regional niche shifts. Shifts in optimum were rare (5% of SRRs with Dopt ≥ 1 pH units) but many species did not show optima within regions. By contrast, shifts in niche width were common (22% of SRRs with Dwidth ≥1 pH units) and there were pronounced interspecific differences. Whereas none of the three predictors significantly explained shifts in niche optimum, common and unique effects of substrate availability and precipitation accounted for 85% of variation in niche width. Our results suggest that substrate availability and precipitation could be the driving factors behind species regional shifts in niche width. Studies that address additional factors, such as other edaphic niches, and their variability at the regional and micro-scale will improve our understanding of the mechanisms underlying species distributions.

KW - Ecosystems Research

KW - competitive ability

KW - ecological modeling

KW - grassland

KW - interspecific variation

KW - nineteenth century

KW - pH

KW - Phytotoxicity

KW - plant

KW - precipitation (climatology)

UR - http://www.scopus.com/inward/record.url?scp=84996497486&partnerID=8YFLogxK

U2 - 10.1111/oik.03369

DO - 10.1111/oik.03369

M3 - Journal articles

AN - SCOPUS:84996497486

VL - 126

SP - 660

EP - 670

JO - Oikos

JF - Oikos

SN - 0030-1299

IS - 5

ER -