Are plant species able to keep pace with the rapidly changing climate?

Future climate change is predicted to advance faster than the postglacial warming. Migration may therefore become a key driver for future development of biodiversity and ecosystem functioning. For 140 European plant species we computed past range shifts since the last glacial maximum and future range shifts for a variety of Intergovernmental Panel on Climate Change (IPCC) scenarios and global circulation models (GCMs). Range shift rates were estimated by means of species distribution modelling (SDM). With process-based seed dispersal models we estimated species-specific migration rates for 27 dispersal modes addressing dispersal by wind (anemochory) for different wind conditions, as well as dispersal by mammals (dispersal on animal's coat – epizoochory and dispersal by animals after feeding and digestion – endozoochory) considering different animal species. Our process-based modelled migration rates generally exceeded the postglacial range shift rates indicating that the process-based models we used are capable of predicting migration rates that are in accordance with realized past migration. For most of the considered species, the modelled migration rates were considerably lower than the expected future climate change induced range shift rates. This implies that most plant species will not entirely be able to follow future climate-change-induced range shifts due to dispersal limitation. Animals with large day- and home-ranges are highly important for achieving high migration rates for many plant species, whereas anemochory is relevant for only few species

第1060回千葉医学会例会・第10回千葉泌尿器科同門会学術集会

Appendix 3 Table A 3: Mean weight of the morphological structures germinule, diaspore and flower head

Phenology of seed ripening, release and wind dispersal

Phenology is the study of periodic life cycle events of living organisms and how these are influenced by environmental factors. Late phenological phases such as the timing of seed release and subsequent seed dispersal considerably affect ecology and evolution in plants. Since plants are mostly sessile organisms, seed dispersal is a crucial life cycle event for the ecology and evolution of plants. In fact, long-distance seed dispersal (LDD) is a very complex process in plant biology and significantly shapes the spatial and temporal dynamics of plant populations. For example, wind dispersal in plants is influenced by a variety of factors such as plant traits, habitat type and environmental conditions (e.g. wind speed). Considering the variability of wind conditions throughout the year, the timing of seed release and dispersal is known to have considerable effects on LDD. Even though late phenologies such as ripening duration and timing of seed release and subsequent dispersal are vital in estimating ecologically highly relevant LDD, these phenologies are not appropriately addressed in ecological research. The aim of this thesis is to gain insights into the factors that shape late plant phenologies. In particular, we address the following questions: which ecologically or evolutionary parameters drive the ripening process of plant species? How does the seasonal variability of wind affect the seed release phenology of plant species? How do these factors interact for plant species in different habitat types? In order to address these questions, we applied different methodological approaches, ranging from fieldwork and monitoring phenology to computational simulation studies and statistical modeling. To study the ripening process of species, we monitored the flowering, ripening and seed release phenology of more than 100 Central European plant species. We conducted computational simulation studies for estimating LDD by wind to study the phenology of seed release and the parameters determining LDD by wind. In conjunction with phenological data from literature, we used the obtained simulation results to investigate evidence for the existence of phenological adaptations towards LDD in 165 plant species. Further, we used the results from simulation studies of LDD by wind to disentangle the effects of species, habitat types and meteorological conditions and their interactions on the spatial spread of plant species. The results of the relationship between plant traits, phylogeny, the ripening process and climatic factors provide insights into the basic understanding of the ripening process of plants. We identified ecological factors that shape species’ ripening phenology and seed release timing. In particular, we suggest that the species’ seed weight, life form and phylogeny shapes ripening and seed release phenology. With the statistical models on species’ temperature demands for reproduction, we introduce data that that are well suitable for parametrization and further development of plant dispersal models. The results from the simulation study based on a seasonal perspective showed that heavier seeded tree species with medium wind dispersal potential (including genera Abies, Acer, Fraxinus and Larix) have a clear synchronisation of seed abscission with periods favouring LDD. These species, which are both ecologically and economically important, showed significant synchronisation of the highest rate of seed release with high wind-speed that promoted LDD by wind in wintertime. For the tree species mentioned, we suggest strong seasonal synchronisation as evidence for phenological adaptations in order to match favourable conditions during seed release. With a closer look at the wind conditions that promote LDD by wind, our results showed considerable differences in how specific wind conditions affect LDD in different species and habitat types. We suggest that LDD by wind in species from open habitats with high wind dispersal potential is likely to be driven by thermal updrafts that are mainly driven by the sun providing energy to the ground. By contrast, LDD of heavier-seeded species from open and forested habitats is more likely to be driven by storms that produce shear-driven turbulence. The results from this thesis contribute to an increased understanding of the complete dispersal process of plants and to making more realistic projections of (future) plant distribution. The results obtained on factors driving ripening and release phenology provide valuable insights into their ecological and phylogenetic factor constraints. The implementation of more realistic assumptions in assessing species’ dispersal potential throughout the year could help considerably in improving landscape management (e.g. timing of mowing) and in the conservation of plant populations. The evidence found for phenological adaptations towards LDD in plants is an important step in understanding the evolutionary basis of LDD in these species

Supplementary material Appendix_4

Appendix 4 Table A 4: Seed terminal velocity (Vterm) and diaspore morphology of species obtained from Hintze et al. (2013)

Supplementary material Appendix_4

Appendix 4 Table A 4: Seed terminal velocity (Vterm) and diaspore morphology of species obtained from Hintze et al. (2013)

Data from: How are the phenologies of ripening and seed release affected by species' ecology and evolution?

The phenology of seed ripening and release are important for dispersal, reproductive success and survival of plants. Most phenological studies, however, consider early phenological phases. Here, we examined the ecological and evolutionary basis of ripening and seed release phenology. We monitored single flower phenology for 104 plant species from 30 families and three life forms from central Europe. Further, we undertook an associate monitoring study along an elevational gradient over two years. We calculated temperature demands (as growing degree days) for ripening and seed release and examined them with respect to the species' seed mass, life form, dispersal mode and phylogeny. We found a strong correlation between species' seed mass and temperature demands for ripening. For both variables seed mass and temperature demands for seed ripening, we found a strong effect of the species phylogeny. These phylogenetic signals strongly indicate that the evolutionary history of the species' lineage affects its seed mass and the temperature demands for seed ripening. Among the studied life forms, shrub species showed the most efficient ripening process. Anemochorous species showed lower relative humidity during seed release than epizoochorous species. For anemochorous species, the synchronisation of release timing with periods that show favourable environmental conditions for wind dispersal could be interpreted as a phenological adaptation to increase dispersal distances. According to the monitoring along the elevational gradient, individuals from higher altitudes showed lower temperature demands for ripening than individuals from lower altitudes. This might tentatively indicate physiological adaptations to lower temperature demands for locations with a shorter growing season. Our study provides basic insights into the ecological, environmental and evolutionary constraints that shape the ripening and seed release phenology of plants. We introduce data that can be used to advance existing models of ripening phenology, seed release and plant spread

Biodiversity loss due to dispersal limitation in terms of the considered 140 plant species.

<p>A) Difference between predicted future distributions (2080) assuming full dispersal and “realistic” dispersal (according to our modelled migration rates taking 27 dispersal modes for migration into account): The differences were calculated for each of the nine environmental models and then averaged. In grey: areas where very few of the 140 species are predicted to occur in 2080 (<10% of the 140 species). B) Uncertainty of the model predictions: Standard deviation of the difference between full dispersal and “realistic” dispersal over the results for the nine environmental models. Projection: Europe Albers Equal Area Conic.</p

General work flow of the study: We compared the modelled potential future range shift rates and the modelled migration rates.

<p>Future range shift rates can be seen as a measure of the distances that are required to be covered per year and the migration rates as a measure for the distances that can be covered by migration per year by plant species. The future range shifts were modelled by means of species distribution modelling (SDM), considering nine different environmental models for 2080. The migration rates were modelled by means of process-based models considering 27 different dispersal modes. For a coarse plausibility check, we tested if the modelled migration rates (maximum level estimation) can explain the modelled postglacial range shifts (minimum level estimation). The postglacial range shifts were also modelled by means of SDM. The comparison of the modelled potential future range shifts and the migration rates was carried out in a direct comparison of the annual rates as well as in a spatial explicit comparison of the potential distributions assuming no migration, full migration and „realistic“ migration (based on the modelled migration rates. We calculated the percentage of the predicted future range that is reached assuming the modelled migration rates for different dispersal modes (range filling).</p

Predicted future range shifts (annual averages) according to the nine environmental models for 2080.

<p>Predicted shifts of the centroids (A) and of the range margins (B). Each boxplot represents N = 140 plant species.</p