Land use modulates resistance of grasslands against future climate and inter-annual climate variability in a large field experiment.

Climate and land-use change are key drivers of global change. Full-factorial field experiments in which both drivers are manipulated are essential to understand and predict their potentially interactive effects on the structure and functioning of grassland ecosystems. Here, we present 8 years of data on grassland dynamics from the Global Change Experimental Facility in Central Germany. On large experimental plots, temperature and seasonal patterns of precipitation are manipulated by superimposing regional climate model projections onto background climate variability. Climate manipulation is factorially crossed with agricultural land-use scenarios, including intensively used meadows and extensively used (i.e., low-intensity) meadows and pastures. Inter-annual variation of background climate during our study years was high, including three of the driest years on record for our region. The effects of this temporal variability far exceeded the effects of the experimentally imposed climate change on plant species diversity and productivity, especially in the intensively used grasslands sown with only a few grass cultivars. These changes in productivity and diversity in response to alterations in climate were due to immigrant species replacing the target forage cultivars. This shift from forage cultivars to immigrant species may impose additional economic costs in terms of a decreasing forage value and the need for more frequent management measures. In contrast, the extensively used grasslands showed weaker responses to both experimentally manipulated future climate and inter-annual climate variability, suggesting that these diverse grasslands are more resistant to climate change than intensively used, species-poor grasslands. We therefore conclude that a lower management intensity of agricultural grasslands, associated with a higher plant diversity, can stabilize primary productivity under climate change.

Quantitative Ultrasound Measurement at the Hand Phalanges Does Not Reveal Skeletal Disturbances in Children With Bronchial Asthma: A Longitudinal Observation.

OBJECTIVES: To assess the skeletal status in asthmatic children treated with inhaled corticosteroids in a longitudinal observation by quantitative ultrasound (US) measurement at the hand phalanges. METHODS: Thirty-four children were studied prospectively. Quantitative US measurements were performed at baseline and after a mean ± SD of 2.35 ± 0.20 years. The obtained results were compared to age-, sex-, and body size-matched control participants selected from a database of previously examined healthy children. Individual changes in the amplitude-dependent speed of sound (Ad-SoS) during the follow-up period were also analyzed. RESULTS: The mean age of the asthmatic children was 10.6 ± 2.5 years. The mean Ad-SoS in the asthmatic children at baseline was 1940.5 ± 49.6 m/s, and the mean Z score was -0.26 ± 0.80. Corresponding values at the follow-up examination were 1976.2 ± 63.6 m/s and -0.18 ± 1.16. The results did not differ significantly in comparison to the healthy controls. The analysis of individual changes in Ad-SoS revealed that 18 participants had a significant increase in this parameter (ie, exceeding the least significant change threshold), and 16 did not have a significant change in their values. No one had a significant decrease in Ad-SoS. CONCLUSIONS: Quantitative US at the hand phalanges applied as a diagnostic tool revealed no essential differences in the pattern of skeletal development between asthmatic children treated with inhaled glucocorticosteroids and healthy controls.

Two common, often coexisting grassland plant species differ in their evolutionary potential in response to experimental drought.

For terrestrial plant communities, the increase in frequency and intensity of drought events is considered as one of the most severe consequences of climate change. While single-species studies demonstrate that drought can lead to relatively rapid adaptive genetic changes, the evolutionary potential and constraints to selection need to be assessed in comparative approaches to draw more general conclusions. In a greenhouse experiment, we compare the phenotypic response and evolutionary potential of two co-occurring grassland plant species, Bromus erectus and Trifolium pratense, in two environments differing in water availability. We quantified variation in functional traits and reproductive fitness in response to drought and compared multivariate genetic variance-covariance matrices and predicted evolutionary responses between species. Species showed different drought adaptation strategies, reflected in both their species-specific phenotypic plasticity and predicted responses to selection indicating contrasting evolutionary potential under drought. In T. pratense we found evidence for stronger genetic constraints under drought compared to more favourable conditions, and for some traits plastic and predicted evolutionary responses to drought had opposing directions, likely limiting the potential for adaptive change. Our study contributes to a more detailed understanding of the evolutionary potential of species with different adaptive strategies in response to climate change and may help to inform future scenarios for semi-natural grassland ecosystems.

The heterogeneity-diversity-system performance nexus.

Ever-growing human population and nutritional demands, supply chain disruptions, and advancing climate change have led to the realization that changes in diversity and system performance are intimately linked. Moreover, diversity and system performance depend on heterogeneity. Mitigating changes in system performance and promoting sustainable living conditions requires transformative decisions. Here, we introduce the heterogeneity-diversity-system performance (HDP) nexus as the conceptual basis upon which to formulate transformative decisions. We suggest that managing the heterogeneity of systems will best allow diversity to provide multiple benefits to people. Based on ecological theory, we pose that the HDP nexus is broadly applicable across systems, disciplines, and sectors, and should thus be considered in future decision making as a way to have a more sustainable global future.

A review of European studies on pollination networks and pollen limitation, and a case study designed to fill in a gap.

Anthropogenic environmental change disrupts interactions between plants and their animal pollinators. To assess the importance of different drivers, baseline information is needed on interaction networks and plant reproductive success around the world. We conducted a systematic literature review to determine the state of our knowledge on plant-pollinator interactions and the ecosystem services they provide for European ecosystems. We focussed on studies that published information on plant-pollinator networks, as a community-level assessment of plant-pollinator interactions and pollen limitation, which assesses the degree to which plant reproduction is limited by pollinator services. We found that the majority of our knowledge comes from Western Europe, and thus there is a need for baseline assessments in the traditional landscapes of Eastern Europe. To address this data gap, we quantified plant-pollinator interactions and conducted breeding system and pollen supplementation experiments in a traditionally managed mountain meadow in the Western Romanian Carpathians. We found the Romanian meadow to be highly diverse, with a healthy plant-pollinator network. Despite the presence of many pollinator-dependent plant species, there was no evidence of pollen limitation. Our study is the first to provide baseline information for a healthy meadow at the community level on both plant-pollinator interactions and their relationship with ecosystem function (e.g. plant reproduction) in an Eastern European country. Alongside the baseline data, we also provide recommendations for future research, and the methodological information needed for the continued monitoring and management of Eastern European meadows.

Mold metabolites drive rheumatoid arthritis in mice via promotion of IFN-gamma- and IL-17-producing T cells.

Environmental factors have been discussed as triggers for autoimmune diseases like rheumatoid arthritis (RA). However, the role of chemical exposures in activation or exacerbation of RA is not clarified yet. Exposure of DBA/1 mice to the mold metabolites ochratoxin A (OTA) or deoxynivalenol (DON) increased the prevalence and the clinical severity of RA compared to un-exposed mice using an experimental collagen-induced arthritis model. Mycotoxin-exposed mice showed enhanced serum IgG1 and IgG2a levels and an elevated production of IL-1ß and IL-6 in inflamed joints and of IFN-γ and IL-17 in splenocytes. Additionally, OTA and DON increased the release of the pro-inflammatory cytokines IL-1ß, IL-6 and TNF-α in activated murine macrophages and supported the differentiation of naïve T cells into Th1 cells, while treatment of CD4+T cells with the supernatant from mycotoxin-exposed macrophages induced IL-17 production. Furthermore, exposure of mice to OTA or DON enhanced the gene expression of Stat1, Stat3 and Stat4 in the spleen while the collagen-induced increase of Socs1 and Socs3 was abolished. Our results demonstrate that mycotoxins increase the susceptibility to develop RA via an enhanced stimulation of macrophages and promotion of Th1/Th17 cell differentiation by induction of Stat signalling pathways and down-regulation of the Socs-mediated feedback inhibition.

Assessment of skeletal status by quantitative ultrasound at the hand phalanges in children with bronchial asthma--a pilot study.

The aim of the study was to assess the skeletal status by quantitative ultrasound measurement at hand phalanges in asthmatic children treated with inhaled corticosteroids. Sixty-nine (69) children with a mean age of 10.9 ± 2.6 y and 251 controls matched for age and body size were enrolled into the study. The mean value of amplitude-dependent speed of sound in asthmatic children was 1953.8 ± 60.2 m/s and the mean Z-score was -0.05 ± 1.02; the corresponding values in the controls were 1951.0 ± 53.9 m/s and -0.26 ± 1.05, respectively. The results did not differ between the asthmatic and the healthy (control) children. A cumulative dose of inhaled steroids was identified in a stepwise regression analysis as a factor with potentially negative influence on bone status. In conclusion, the skeletal status in asthmatic children, assessed by quantitative ultrasound, shows no difference in comparison with healthy children. Nonetheless, special caution is necessary in case of long-term corticosteroid therapy, in which a slightly negative influence of treatment on the skeleton cannot be excluded.