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The life cycle of plants is largely determined by climate, which renders phenological responses to climate change a highly suitable bioindicator of climate change. Yet, it remains unclear, which are the key drivers of phenological patterns at certain life stages. Furthermore, the varying responses of species belonging to different plant functional types are not fully understood. In this study, the role of temperature and precipitation as environmental drivers of phenological changes in southern Europe is assessed. The trends of the phenophases leaf unfolding, flowering, fruiting, and senescence are quantified, and the corresponding main environmental drivers are identified. A clear trend towards an earlier onset of leaf unfolding, flowering, and fruiting is detected, while there is no clear pattern for senescence. In general, the advancement of leaf unfolding, flowering and fruiting is smaller for deciduous broadleaf trees in comparison to deciduous shrubs and crops. Many broadleaf trees are photoperiod-sensitive; therefore, their comparatively small phenological advancements are likely the effect of photoperiod counterbalancing the impact of increasing temperatures. While temperature is identified as the main driver of phenological changes, precipitation also plays a crucial role in determining the onset of leaf unfolding and flowering. Phenological phases advance under dry conditions, which can be linked to the lack of transpirational cooling leading to rising temperatures, which subsequently accelerate plant growth. [ABSTRACT FROM AUTHOR]

Abstract: The CARAIB (CARbon Assimilation In the Biosphere) model is used to study the vegetation distribution during the Late Miocene (Tortonian). In this version, the plant classification is specifically adapted to best represent Miocene European vegetation. Compared to other plant classifications used in global models, this adapted classification is more refined, since it is specifically developed for European vegetation and it includes various thermophylous tree types, which were present in Europe during the Miocene. The corresponding climatic tolerance parameters are based on the study of ) for the tree types currently present in Europe and on the distribution of analogue species in southeastern Asia and North/Central America for the thermophylous (sub-tropical) trees. The same classification is used to characterize the palaeoflora at the available Late Miocene localities, allowing a model–data comparison at the plant functional type level, rather than at the biome level. The climatic inputs to CARAIB are obtained from the COSMOS atmosphere–ocean general circulation model. The climatic anomalies (Tortonian minus Present) derived from COSMOS are interpolated to a higher spatial resolution before being used in the vegetation model. These anomalies are combined with a modern climatology to produce climatic fields with high spatial resolution (10′×10′). This procedure has the advantage of making apparent relief features smaller than the grid cells of the climate model and, hence, makes easier the comparison with local vegetation data, although it does not really improve the quality of the Tortonian climate reconstruction. The new version of CARAIB was run over Europe at this higher spatial resolution. It calculates the potential distribution of 13 different classes of trees (including cold/cool/warm-temperate, sub-tropical and tropical types), together with their cover fractions, net primary productivities and biomasses. The resulting model vegetation distribution reconstructed for the Tortonian is compared to available palaeovegetation and pollen data. Before performing this comparison, the tree taxa present at the various data sites are assigned to one or several model classes, depending on the identification level of the taxa. If several classes are possible for a taxon, only those that can co-exist with the other tree classes identified at the site are retained. This methodology is similar to the co-existence approach used in palaeoclimatic reconstructions based on vegetation data. It narrows the range of tree types present at the various sites, by suppressing in the data the extreme types, such as the cold boreal/temperate and tropical trees. The method allows a comparison with the model simulation on a presence/absence basis. This comparison provides an overall agreement of 53% between the model and the data, when all sites and tree types are considered. The agreement is high (>85%) for needle-leaved summergreen boreal/temperate cold trees (Larix sp.) and for tropical trees, intermediate (>40%) for other boreal/temperate cold trees and for needle-leaved evergreen temperate cool trees, broadleaved summergreen temperate cool trees and broadleaved evergreen warm-temperate trees, and poor (<40%) for most temperate perhumid warm trees. In many cases, the model is shown to be better at predicting the absence than the presence, as observed for tropical trees. The modelled distributions of cold boreal/temperate trees tend to extend too much towards the south compared to the data. By contrast, model sub-tropical trees (temperate perhumid warm and needle-leaf summergreen temperate warm trees) appear to be restricted to some limited areas in southern Europe, while they are present in the data from central Europe up to at least 50°N. Consequently, modelled Late Miocene climate appears to remain too cold to produce assemblages of trees consistent with the data. The predicted modelled trends from the past to the present are in the right direction, but the amplitude remains too small. For the simulations to be in a better agreement with the data, higher CO2 levels may be necessary in the climate simulations, or possibly other oceanic boundary conditions may be required, such as different bathymetry in the Panama seaway. [Copyright &y& Elsevier]

• Individual-based model reproduces four vegetation attributes of temperate grassland. • Competition for space has a stronger influence than competition for light. • Traits affecting either growth or demographic processes can strengthen PFTs. • Model simulates positive effect of functional richness on productivity. Grasslands are an important habitat for many plant species whose functional diversity and composition influences ecosystem functioning and services. Despite several field studies, still uncertainties remain about the interplay of species traits and ecosystem processes that lead to the functional diversity observed in grasslands. Here, we used an individual-based process-oriented model to simulate a biodiversity field experiment located in Central Europe. With the focus on plant functional types (PFT), the simulation model well reproduced vegetation attributes of grassland communities at different diversity levels (of up to four PFTs of grasses, small herbs, tall herbs and legumes). To understand how plant traits and competition between plants affects the functional composition of grasslands, we tested in a simulation study the impact of different ecosystem processes and detected sensitive plant traits. According to our model results, competition for space affects community productivity stronger than competition for light. While some traits increase and strengthen the growth of plants, other functional traits make plants stronger through advantages in demographic processes. Our model-based findings can be substantiated by several independent field studies in terms of relative yield, plant density, plant biomass and life span of plant functional types. The methods and analyses shown here represent a promising step for the development of grassland models to investigate the complex structures and dynamics of temperate grasslands in complement to field studies. [ABSTRACT FROM AUTHOR]

• Grime's CSR strategy theory broadly explains the invasion success of alien plant species. • Invasive alien and native plant species occupy the same region within the CSR space. • Invasive alien plant species are true competitors. • CSR theory can be a viable tool for the risk assessment of invasive alien plant species. Invasive alien species (IAS) are the subset of naturalized species that cause greater impacts on biodiversity, ecosystem functions and services. However, despite management actions and eradication plans, their expansion worldwide is seemingly unstoppable. In this paper, based on a large dataset of 1039 records of IAS and native plant species representative of the extensive biogeographic diversity in Southern Europe, we tested the consistency of Grime' concept of CSR universal adaptive strategies (competitors, stress-tolerators and ruderals) to explain plant invasion across a broad elevation gradient. Accounting for phylogenetic relatedness, we tested two hypotheses. First, whether IAS occupy a different CSR space compared to native species. Second, whether the success of IAS at the regional scale is linked to higher degree of C- and/or R-selection, according to recent worldwide observations on naturalization success of alien species. We tested such hypotheses on different growth forms (trees, shrubs, long-lived herbs, short-lived herbs, hydrophytes) that are related to plant functional traits. Except for trees, IAS and native plant species essentially occupied the same CSR space, indicating that IAS can occupy the same niches of native species. However, IAS exhibited mainly higher C- scores compared to natives, suggesting that IAS are more competitive and are associated with relatively productive habitats, involving that these sites are highly prone to invasion (and that native species in resource-poor habitats are less likely to experience pressure from IAS). Our findings confirm the utility of CSR classification to broadly represent, and explain, the invasion success of alien plant species at the regional scale. This approach emerges as a viable tool in assessment of IAS characteristics and for development of strategies and plans for their containment. [ABSTRACT FROM AUTHOR]