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Questions: Semi‐natural grasslands in Southern Europe are biodiversity hotspots, yet their patterns of plant species richness are less studied than in Central Europe. In the Central Apennines (Italy), there are large areas of dry calcareous grasslands, across a steep gradient of mean annual precipitation (from 650 to 1350 mm within c. 30 km). We asked: How do these grasslands compare to other Palaearctic grasslands in richness levels? How do the precipitation gradient and other environmental predictors influence species richness? Does this influence differ among taxonomic groups? Location: Submontane and lower‐montane belt of the Central Apennines (Abruzzo and Lazio, Italy). Methods: We recorded the species richness of vascular plants and (terricolous) bryophytes and lichens in 97 plots of 10 m2, aligning them with the precipitation gradient while maintaining geological substrate and elevation similar. Mean temperature and precipitation were estimated with a high‐resolution regional model. A wide array of environmental variables (including soil properties and grazing load) were measured for each plot. Multivariate relationships within and between response and predictor variables were studied with Canonical Correlation. The relative importance of predictors on response variables was modeled with Boosted Regression Trees. Results: The sampled grasslands were very species‐rich in the Palaearctic context. Vascular plant richness was negatively influenced by topographic heat load and soil sand content, but we did not detect a relationship with mean annual precipitation. Bryophyte richness was poorly modeled by the measured variables, although it was positively correlated with lichen richness. Lichen richness had a marked negative relationship with soil phosphorus and mean annual precipitation. Conclusions: In Southern European semi‐natural mountain grasslands, vascular plant richness is driven more by fine‐scale edaphic factors than by precipitation gradients. In contrast, bryophyte and lichen species richness is predicted by a mixture of climatic and edaphic variables. [ABSTRACT FROM AUTHOR]

The role of plant traits in shaping community assembly along environmental gradients is a topic of ongoing research. It is well accepted that plant traits of aboveground organs tend to be conservative in stressful conditions. However, there is limited understanding of how belowground traits respond. Plants may have similar strategies above and belowground, but an intriguing possibility is that there is a tradeoff between above and belowground traits of communities to both ensure efficient resource‐use and limit niche overlap along the gradient. To test this, we asked whether the response of above and belowground traits of communities is coordinated or not along a stress gradient in Mediterranean sand dune communities. We analyzed 80 vegetation plots in central Italy to test for coordinated vs independent patterns in above vs belowground plant traits using community weighted mean and standardized effect size of functional richness. Our results show that plant communities close to the sea, which experience higher stress, were characterized by higher convergence towards aboveground resource conservation and conservative water‐use strategies but belowground resource acquisition, consistent with a strong effect of habitat filtering and an above–belowground tradeoff favoring adaptation to harsh and dry conditions. At the opposite end of the gradient with lower stress, plants exhibited higher trait diversity for both above and belowground traits, but overall a dominance of aboveground fast resource acquisition and generally acquisitive water‐use strategies, combined with conservative belowground strategies. This suggests that fast growth rate aboveground was compensated by more conservative fine‐root strategies, but processes such as competition limited niche overlap overall. Our findings provide new insights into the relationship between functional traits and environmental gradients in plant communities, shedding light on the tradeoffs between the above and belowground dimensions. [ABSTRACT FROM AUTHOR]

We introduce RanVegDunes (GIVD ID EU-IT-020) , the first Italian database gathering standardized, randomly-sampled vegetation data in coastal dune environments. RanVegDunes currently consists of 979 original georeferenced relevés randomly collected over about 160 km of Holocenic dune systems of central Italy between 2002 and 2015. Plots were located in five Italian administrative regions (Lazio, Campania, Abruzzo, Molise and Puglia), where sandy vegetation was randomly recorded in standardized 4-m2 plots across the whole coastal zonation, thus including upper beach, embryo dunes, shifting dunes, dune grasslands, wooded dunes and Mediterranean forests. Each plot was georeferenced with a high level of accuracy using a GPS unit. For each plot, a list of vascular plant species based on updated nomenclature was compiled, and an estimate of abundance was calculated for each species using a percentage cover scale ranging from 1 to 10 (1 = 1-10%; 2 = 10-20%; ...; 10 = 90-100%). Two habitat classification systems were used for the description of collected plots: specifically, each vegetation plot was classified according to the Interpretation Manual of the 92/43/EEC Habitats Directive and also to the hierarchical structure of the EUNIS habitat classification. Currently, RanVegDunes includes vegetation plots belonging to nine EU Habitats (1210, 2110, 2120, 2210, 2230, 2250, 2260, 2270, 9340), which in turn correspond to five EUNIS Habitats (B1.1, B1.3, B1.4, B1.6, B1.7). RanVegDunes is a powerful tool for a variety of studies addressing topics such as temporal trends in coastal vegetation, ecological modeling, re-visitation studies, spatio-temporal patterns of invasion and will therefore greatly benefit from further collection of data. [ABSTRACT FROM AUTHOR]

Festuca valesiaca Schleich. ex Gaudin subsp. valesiaca is acknowledged as one of the most characteristic grasses of the continental grasslands and steppes of Eurasia. In Italy, the species was known almost only from the continental valleys of the Alpine chain (with the exception of two small populations at the northernmost edge of the Apennines). Here, we report on the first confirmed finding of F. valesiaca subsp. valesiaca in the surroundings of the Fucino Basin, Central Apennines. This finding expands by c. 400 km southwards the species' range in Italy. The identity of the species was first ascertained by means of leaf cross-sections and stomata measurements, and then confirmed by chromosome count. Its habitat preferences within the area were found to match well with those described in the literature for C-Europe. After discussing some identification issues and the population's ecological niche, we present the main biogeographic implications of our finding. By recalling and discussing similar examples, we conclude that during the Holocene forest spread some Apennine "dry valleys" performed as refugia for a number of Pleistocene steppic taxa. The grasslands of these areas may thus be ancient and valuable ecosystems maintained by climate and disturbance throughout the Holocene. [ABSTRACT FROM AUTHOR]