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1. The species richness-productivity relationship is one of the most debated patterns in ecology. Species coexistence theory suggests that it could be tightly linked to the type of nutrient limitation (no limitation, single-nutrient limitation, colimitation by several nutrients). Yet, the effects of nutrient limitation on the species richness-productivity relationship have been rarely studied at the regional and continental scales.2. Combining the predictions of the humped-back model and the niche dimension hypothesis, we hypothesized that an increase in plant species richness with the number of different limiting nutrients is detectable only at higher productivity levels, at which competition for nutrients is more intense. Therefore, we expected the shape of the diversity-productivity relationship to differ between sites colimited by nitrogen (N) and phosphorus (P), sites limited by a single nutrient (either N or P), and sites not limited by any of these nutrients.3. To test this hypothesis, we used species richness data collected in 10 m × 10 m plots at 694 temperate dry grassland sites across eight regions in northern Eurasia.Productivity ranged from 10 to ~500 g/m 2 of above-ground standing biomass. The type of nutrient limitation was identified by critical nutrient ratios alone and their combination with critical nutrient concentrations measured in the plant tissue.Relationships were analysed using generalized linear and mixed-effect models. 4. In line with our expectations, species richness of Eurasian temperate dry grasslands increased more steeply and peaked higher under higher productivity levels at N&P-colimited sites. When nutrient limitation was assessed by both ratios and concentrations, species richness at N&P-colimited sites continued to increase | 1039 Journal of Ecology PALPURINA et AL. S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Palpurina S, Chytrý M, Hölzel N, et al. The type of nutrient limitation affects the plant species richness-productivity relationship: Evidence from dry grasslands across Eurasia.

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Question How does the species composition and functional structure of flood‐meadows change over time during a period with strong variations in flooding frequency and height? Location Flood‐meadows at the northern Upper Rhine, Germany. Methods From 1998 to 2004 annually, and again in 2008, species composition and above‐ground biomass were studied in 46 permanent plots located along a flooding gradient ranging from frequently flooded Magnocaricion to rarely flooded Arrhenaterion meadows. The plots were situated in the functional floodplain (natural) and in the fossil floodplain on the land side of high winter levees (anthropogenic altered). Temporal variation of the functional structure was analysed based on community‐weighted mean traits. Results Productivity and functional structure varied markedly over the study period and between the functional and fossil floodplain. During the study period two contrasting extreme events occurred: a summer flood in 1999 and a drought period after 2003. After the flood in 1999, species composition and functional structure of the studied flood‐meadows shifted towards the species composition of wetter sites. Flooding reduced species richness in the functional floodplain, but not in the fossil floodplain. Conclusions Flood‐meadows in the Upper Rhine fully recover from extreme disturbance events within a time frame of less than 10 yr. Environmental fluctuations and disturbances, enabling the co‐existence of species with contrasting ecological requirements are a key factor for the preservation of plant biodiversity in flood‐meadows.