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Ranunculus acris L. is a native species widely distributed throughout Europe and is invasive in nonnative areas, causing substantial economic losses in pasture productivity. The present study examined the effects of sodic salinity on the growth and functioning of this species. Salinity stresses the germination process and seedling growth, indicating that the studied species experience serious limitations at 60–90 mmol dm−3 NaCl and cannot establish in habitats where salinity is equal to or greater than 150 mmol dm−3 NaCl. R. acris is tuned to subsaline habitats characteristic of temperate meadows, as its growth and functioning were the best when the plants were treated with 30 mmol dm−3 NaCl. Increasing salinity (60 and 90 mmol dm−3 NaCl) hampered growth, leaf morphology and photosynthesis but not mineral nutrition, as Na accumulation seemed to be the most outlined effect of NaCl application. Changes in leaf morphological characteristics coordinated well with Na content in those organs, which indicates that leaf appearance can be easily catchable sign of progressing salinity. Ultimately, progressing salinity reduces the competitiveness of the studied species, shifting its strategy to ruderal behavior, but under subsaline conditions, the strategy of this species seems to be most balanced. [ABSTRACT FROM AUTHOR]

Climate change associated with a greater variability of inter‐ and intra‐annual droughts and the occurrence of extreme events act in combination to challenge semi‐natural and sown productive grasslands in Europe. Successful plant strategies under drought strongly depend on stress intensity. Drought resistance to maintain leaf growth under moderate stress trades off with drought survival after growth cessation under life‐threatening drought. Substantial intra‐specific variability exists in key forage grasses originating from the Mediterranean to the cool‐temperate climates and represents a great potential for adaptation of future ecotypes and cultivars to a larger range of drought intensities. Plant species diversity offers an opportunity to stabilize forage production in two ways. First, growth reduction under stress is significantly smaller for diverse compared to simple plant communities because the former offers the opportunity to include drought‐resistant (or drought‐surviving) species. Second, positive interactions among species increase ecosystem functioning of more diverse plant communities under moderate drought, allowing them to compensate for drought‐induced yield reductions. Currently, available cultivars of perennial forage species adapted to dry climate are still rare and only a few forage species are used in productive systems. Thus, both intra‐ and inter‐specific plant diversity should be better valued to reduce vulnerability and increase resilience of productive grasslands. [ABSTRACT FROM AUTHOR]

Annually resolved tree-ring records extending back to pre-industrial conditions have the potential to constrain the responses of global land surface models at interannual to centennial timescales. Here, we demonstrate a framework to simultaneously constrain the representation of tree growth and physiology in the ORCHIDEE global land surface model using the simulated variability of tree-ring width and carbon (Δ13 C) and oxygen (δ18 O) stable isotopes in six sites in boreal and temperate Europe. We exploit the resulting tree-ring triplet to derive integrative constraints for leaf physiology and growth from well-known mechanistic relationships among the variables. ORCHIDEE simulates Δ13 C (r=0.31 –0.80) and δ18 O (r=0.36 –0.74) better than tree-ring width (r<0.55), with an overall skill similar to that of a tree-ring model (MAIDENiso) and another isotope-enabled global vegetation model (LPX-Bern). The comparison with tree-ring data showed that growth variability is not well represented in ORCHIDEE and that the parameterization of leaf-level physiological responses (stomatal control) to drought stress in the temperate region can be constrained using the interannual variability of tree-ring stable isotopes. The representation of carbon storage and remobilization dynamics emerged as a critical process to improve the realism of simulated growth variability, temporal carryover, and recovery of forest ecosystems after climate extremes. Simulated forest gross primary productivity (GPP) correlates with simulated tree-ring Δ13 C and δ18 O variability, but the origin of the correlations with tree-ring δ18 O is not entirely physiological. The integration of tree-ring data and land surface models as demonstrated here should guide model improvements and contribute towards reducing current uncertainties in forest carbon and water cycling. [ABSTRACT FROM AUTHOR]

Annually-resolved tree-ring records extending back to pre-industrial conditions have the potential to constrain the responses of global land surface models at interannual to centennial time scales. Here, we demonstrate a framework to constrain the representation of tree growth and physiology in the ORCHIDEE global land surface model using the simulated variability of tree-ring width and carbon (Δ13C) and oxygen (δ18O) stable isotopes in six sites in boreal and temperate Europe. We exploit the tree-ring triplet to derive integrative constraints for leaf physiology and growth from well-known mechanistic relationships among the variables. The model simulates Δ13C (r = 0.31-0.80) and δ18O (r = 0.36-0.74) better than tree-ring width (r < 0.55), with an overall skill similar to that of other models. The results show that growth variability is not well represented, and that the parameterization of leaf-level physiological responses to drought stress in the temperate region can be improved with tree-ring data. The representation of carbon storage and remobilization dynamics is critical to improve the realism of simulated growth variability, temporal carrying over and recovery of forest ecosystems after climate extremes. The simulated physiological response to rising CO2 over the 20th century is consistent with tree-ring data in the temperate region, despite an overestimation of seasonal drought stress and stomatal control on photosynthesis. Photosynthesis correlates directly with isotopic variability, but the origin of correlations with δ18O is not entirely physiological. The integration of tree-ring data and land surface models as demonstrated here should contribute towards reducing current uncertainties in forest carbon and water cycling. [ABSTRACT FROM AUTHOR]

Tuta absoluta ( Meyrick) is an invasive pest of tomato native to South America, where it is responsible for extensive damage. It rapidly spread into several European countries, becoming a key pest. Knowledge of its main biological traits can be used to develop effective plant protection management strategies. It is a multivoltine species with a homodynamous behaviour, and the length of its life cycle depends on environmental conditions, particularly temperature. The larvae feed and develop inside tomato leaves, stems and fruits throughout the entire growing cycle. The adults have crepuscular habits, and in Mediterranean conditions they can be easily detected throughout the year. Damage is directly related to the reduction of plants' photosynthetic capacity and of production levels in both protected and open-field tomato crops; indirect damage can be also caused by secondary infections, with pathogens developing on the infested plant and fruit tissues. [ABSTRACT FROM AUTHOR]

Abstract: The study aimed to explore if changes in crown defoliation and stem growth of Scots pines (Pinus sylvestris L.) could be related to changes in ambient ozone (O3) concentration in central Europe. To meet this objective the study was performed in 3 Lithuanian national parks, close to the ICP integrated monitoring stations from which data on meteorology and pollution were provided. Contribution of peak O3 concentrations to the integrated impact of acidifying compounds and meteorological parameters on pine stem growth was found to be more significant than its contribution to the integrated impact of acidifying compounds and meteorological parameters on pine defoliation. Findings of the study provide statistical evidence that peak concentrations of ambient O3 can have a negative impact on pine tree crown defoliation and stem growth reduction under field conditions in central and northeastern Europe where the AOT40 values for forests are commonly below their phytotoxic levels. [Copyright &y& Elsevier]

Accurate estimation of the timing of intensive spring leaf growth initiation at mid and high latitudes is crucial for improving the predictive capacity of biogeochemical and Earth system models. In this study, we focus on the modeling of climatological onset of spring leaf growth in Central Europe and use three spring phenology models driven by three meteorological datasets. The MODIS-adjusted NDVI3g dataset was used as a reference for the period between 1982 and 2010, enabling us to study the long-term mean leaf onset timing and its interannual variability (IAV). The performance of all phenology model–meteorology database combinations was evaluated with one another, and against the reference dataset. We found that none of the constructed model–database combinations could reproduce the observed start of season (SOS) climatology within the study region. The models typically overestimated IAV of the leaf onset, where spatial median SOS dates were best simulated by the models based on heat accumulation. When aggregated for the whole study area, the complex, bioclimatic index-based model driven by the CarpatClim database could capture the observed overall SOS trend. Our results indicate that the simulated timing of leaf onset primarily depends on the choice of model structure, with a secondary contribution from the choice of the driving meteorological dataset. [ABSTRACT FROM AUTHOR]

The quality of yield prediction is linked to that of leaf area. We first analysed the consequences of flowering time and environmental conditions on the area of individual leaves in 127 genotypes presenting contrasting flowering times in fields of Europe, Mexico, and Kenya. Flowering time was the strongest determinant of leaf area. Combined with a detailed field experiment, this experiment showed a large effect of flowering time on the final leaf number and on the distribution of leaf growth rate and growth duration along leaf ranks, in terms of both length and width. Equations with a limited number of genetic parameters predicted the beginning, end, and maximum growth rate (length and width) for each leaf rank. The genotype-specific environmental effects were analysed with datasets in phenotyping platforms that assessed the effects (i) of the amount of intercepted light on leaf width, and (ii) of temperature, evaporative demand, and soil water potential on leaf elongation rate. The resulting model was successfully tested for 31 hybrids in 15 European and Mexican fields. It potentially allows prediction of the vertical distribution of leaf area of a large number of genotypes in contrasting field conditions, based on phenomics and on sensor networks., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology.)