The detailed scientific programme is available here as a pdf file:

PLENARY LECTURES

Michal GRABOWSKI (University of Lodz, Poland)

European freshwater biota -

from rise of the continent to human impact

Monday, 4 July, 9h

In general view, Europe is recognised as less interesting field for biodiversity studies than the tropical regions of the world. Such opinion is biased mostly by comparably low number of formally described species especially in such flagship taxa as vertebrates, insects or molluscs and by the believable calamitous role of Pleistocene glaciations in shaping European biodiversity.

Such view has begun to change with, published nearly twenty years ago, works upon “genetic legacy of Quaternary ice ages” by the late Godfrey Hewitt and his team. This already classical set of publications presented an intricate pattern of distribution of numerous phylogenetic lineages within formally recognised species, surviving and diversifying during ice ages in several southern glacial refugia and then recolonising more northern regions of Europe. Numerous further studies have brought even more intriguing information, particularly in case of freshwater biota. Unexpected presence of glacial refugia was discovered in northern regions of Europe. In case of several groups, such as crustaceans, extraordinarily high level of cryptic diversity and deep divergence within morphospecies were revealed. This showed that their evolutionary history in Europe reaches far beyond Pleistocene and dates back to the very beginning of Europe as a continent that we know now. The knowledge questioned the widely accepted Banarescu’s view on biogeography of freshwaters in Europe. Looking at the new level of diversity has also greatly enhanced taxonomic studies and affected the rationale behind nature conservation.

Such accumulation of information upon the real extent of diversity and origins of European freshwater biota has overlapped in time with ongoing colonisation of local inland waters by various nonindigenous invasive species. Their routes and pathways of dispersal as well as consequences for local ecosystems are another fascinating research program. During my talk I will provide the audience with outline of the dynamic changes of European paleogeography and associated climate changes, showing how they affected the present day diversity and distribution of main freshwater taxonomic groups. I will also cover the most recent changes in biodiversity patterns in inland waters due to spread of invasive species. The talk will be illustrated with a wide selection of case studies coming both from my team’s published and unpublished works as well as from other sources.

Florian LEESE (University of Duisburg-Essen, Germany)

From genes to ecosystems: Assessing stressor effects

on freshwater macroinvertebrates with genomic approaches

Tuesday, 5 July, 9h

As a consequence of anthropogenic action, freshwater ecosystems have been drastically degraded over the past centuries with severe consequences for biodiversity and ecosystem function. To counteract degradation, many restoration efforts from small and local to large international catchment-spanning activities have been launched. Here, macroinvertebrates are central indicators to quantify the loss of biodiversity in response to anthropogenic stressors and its subsequent recovery. Unfortunately, determination of macroinvertebrates with morphological methods, specifically of their juvenile stages, is difficult and frequently leads to incorrect results. In addition, the level of genetic variation is not included in the contemporary approaches. Therefore, current assessments are limited in their power to gain deeper process understanding. In my talk I will outline how genetic and genomic tools can be routinely applied to study responses of macroinvertebrates to stressors. Using case studies from Europe and New Zealand, I will outline how the impact of stressors on populations can be studied using genetic and genome-wide polymorphism data. The data show that critically important responses of biodiversity are overlooked when only relying on morphological data. Second, I will show how DNA-metabarcoding can be routinely integrated into present-day biodiversity assessment to improve biodiversity – ecosystem function responses to environmental stressors.

David BILTON (Plymouth University, UK)

Comparative ecophysiology, rarity and vulnerability

 to global change in aquatic insects

Thursday, 7 July, 9h

Most species are rare, with relatively small geographical ranges, comparatively few organisms being naturally widespread. This pattern is commonly observed within individual clades, including many freshwater taxa. Individual genera are often dominated by narrow range endemics, but frequently include a handful of widespread species, which are ecologically and morphologically similar to their more restricted relatives.  A variety of ecological and evolutionary processes may underlie such range size variation, one of the most popular hypotheses suggesting that widespread species have broader fundamental niches than narrow range taxa.  Despite this common assumption, there have been very few empirical tests of such ideas. Variation in physiology can play a pivotal role in determining differences in niche breadth, predicting that widespread taxa will have broader ranges of physiological tolerance than restricted-range relatives, providing a potential means of testing niche theories of rarity.

My talk will summarize work over the last decade which has explored these ideas, mainly in water beetles, by studying closely related species which often differ dramatically in the extent of their geographical distributions. I argue that within a given habitat type physiological tolerance appears to be strongly associated with both range size and position, but that shifts between habitats may drive dramatic changes in distribution. I will go on to consider how such comparative studies may lead to a better understanding of organismal responses to global change, through both direct and indirect effects in nature.

Pavel KRATINA (Queen Mary University of London, UK)

Indirect impacts of climate warming

in pelagic and benthic food webs

Friday, 8 July, 9h

Rising temperatures, declining predator populations and eutrophication are three pervasive pressures affecting aquatic ecosystems. These processes may interact in a number of ways that are likely to vary seasonally, as temperature affects consumer-resource interactions and metabolic processes. We used a year-long experiment with 1200 L mesocosms to investigate the combined effects of warming, nutrient load and fish predation on freshwater communities. We observed strong top-down and bottom-up effects on plankton communities, and these effects varied over time. Enhancement of phytoplankton biomass with added nutrients is strongest when fish are present, primarily due to fish predation on large cladocerans. Warming enhances trophic cascades (particularly during winter) and reduces effects of eutrophication (particularly in summer). Although fish had significant cascading effects in both benthic and pelagic environments, the interactive effects of fish and temperature were substantially weaker along benthic and detrital pathways. This suggests that more reticulate benthic compartments may be more resistant to climate warming than simple pelagic food chains. We also show that fish predation suppresses the emergence of aquatic organisms into terrestrial ecosystems and reduces decomposition of terrestrial detritus in aquatic ecosystems. On the other hand, warming and nutrients both enhance cross-ecosystem fluxes, especially in systems without fish. Warming also increased net ecosystem production, while reducing the standing biomass of the dominant primary producers, indicating that warming speeds up energy movement throughout food webs. Our results show that the effects of simultaneous perturbations are often synergistic rather than independent. This indicates that the impacts of undergoing global warming will depend on local nutrient status or predator abundance.