Microarthropod communities and their ecosystem services restore when permanent grassland with mowing or low-intensity grazing is installed

The current focus on intensification and maximizing productivity in agriculture can endanger soil biota and the ecosystem services they provide in such a way that it acts counterproductive and increases the dependence on external inputs. In this study, we aimed to identify the factors that are most limiting for the restoration of soil biota and their ecosystem services on sandy soils. To this end, we assessed microarthropod communities, their relationship with the aboveground food web and their effect on organic matter decomposition, in two land-use types: grasslands with agricultural land use and grasslands with nature land use. The latter are grasslands converted from agricultural land use, for the development of the Dutch National Ecological Network. For these land-use types, we took into account two main factors of disturbance: the number of years since the last tillage (i.e., plowing event), and the current grassland management (mowing or grazing). We found that the diversity of microarthropods was higher in nature grasslands than in agricultural grasslands. The abundance of microarthropods increased with time since last tillage for grasslands that were mown, but not for grasslands that were grazed. An agricultural grassland without tillage since 39 years had a microarthropod abundance similar to reference natural grasslands reported in previous research. The number of predatory beetles increased with a higher microarthropod abundance in mown grasslands, but not so in grazed grasslands. The number of fungivorous and herbofungivorous grazer microarthropods positively influenced the decomposition of soil organic matter as measured with the Tea Bag Index. Furthermore, we found a negative effect of Difenyl and total fungicide concentrations in the soil on (herbo)fungivorous grazers. Contrary to our expectations, we found more pesticide residues in nature grasslands than in agricultural grasslands. In conclusion, to restore the soil microarthropods and the ecosystem services they contribute to, the best practice is to strive for permanent grassland (without tillage) with mowing or low-intensity grazing (without compaction of the topsoil)

Alternative transient states and slow plant community responses after changed flooding regimes

Climate change will have large consequences for flooding frequencies in freshwater systems. In interaction with anthropogenic activities (flow regulation, channel restoration and catchment land-use) this will both increase flooding and drought across the world. Like in many other ecosystems facing changed environmental conditions, it remains difficult to predict the rate and trajectory of vegetation responses to changed conditions. Given that critical ecosystem services (e.g. bank stabilization, carbon subsidies to aquatic communities or water purification) depend on riparian vegetation composition, it is important to understand how and how fast riparian vegetation responds to changing flooding regimes. We studied vegetation changes over 19 growing seasons in turfs that were transplanted in a full-factorial design between three riparian elevations with different flooding frequencies. We found that (a) some transplanted communities may have developed into an alternative stable state and were still different from the target community, and (b) pathways of vegetation change were highly directional but alternative trajectories did occur, (c) changes were rather linear but faster when flooding frequencies increased than when they decreased, and (d) we observed fastest changes in turfs when proxies for mortality and colonization were highest. These results provide rare examples of alternative transient trajectories and stable states under field conditions, which is an important step towards understanding their drivers and their frequency in a changing world

Alternative transient states and slow plant community responses after changed flooding regimes

Climate change will have large consequences for flooding frequencies in freshwater systems. In interaction with anthropogenic activities (flow regulation, channel restoration and catchment land-use) this will both increase flooding and drought across the world. Like in many other ecosystems facing changed environmental conditions, it remains difficult to predict the rate and trajectory of vegetation responses to changed conditions. Given that critical ecosystem services (e.g. bank stabilization, carbon subsidies to aquatic communities or water purification) depend on riparian vegetation composition, it is important to understand how and how fast riparian vegetation responds to changing flooding regimes. We studied vegetation changes over 19 growing seasons in turfs that were transplanted in a full-factorial design between three riparian elevations with different flooding frequencies. We found that (a) some transplanted communities may have developed into an alternative stable state and were still different from the target community, and (b) pathways of vegetation change were highly directional but alternative trajectories did occur, (c) changes were rather linear but faster when flooding frequencies increased than when they decreased, and (d) we observed fastest changes in turfs when proxies for mortality and colonization were highest. These results provide rare examples of alternative transient trajectories and stable states under field conditions, which is an important step towards understanding their drivers and their frequency in a changing world

‘Integrative Physiology 2.0’: integration of systems biology into physiology and its application to cardiovascular homeostasis

Since the completion of the Human Genome Project and the advent of the large scaled unbiased ‘-omics’ techniques, the field of systems biology has emerged. Systems biology aims to move away from the traditional reductionist molecular approach, which focused on understanding the role of single genes or proteins, towards a more holistic approach by studying networks and interactions between individual components of networks. From a conceptual standpoint, systems biology elicits a ‘back to the future’ experience for any integrative physiologist. However, many of the new techniques and modalities employed by systems biologists yield tremendous potential for integrative physiologists to expand their tool arsenal to (quantitatively) study complex biological processes, such as cardiac remodelling and heart failure, in a truly holistic fashion. We therefore advocate that systems biology should not become/stay a separate discipline with ‘-omics’ as its playing field, but should be integrated into physiology to create ‘Integrative Physiology 2.0’