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AbstractSeagrasses are foundation species that provide ecosystem functions and services, including increased biodiversity, sediment retention, carbon sequestration, and fish nursery habitat. However, anthropogenic stressors that reduce water quality, impose large‐scale climate changes, and amplify weather patterns, such as marine heatwaves, are altering seagrass meadow configurations. Quantifying large‐scale trends in seagrass distributions will help evaluate the impacts of climate drivers on their functions and services. Here, we quantified spatiotemporal dynamics in abundances and configurations of intertidal and shallow subtidal seagrass (Zostera muelleri) meadows in 20 New Zealand (NZ) estuaries that span a 5‐year period (mid/late 2016–early 2022) just before, during and after the Tasman Sea 2017/18 marine heatwave, the warmest summer ever recorded in NZ. We used high‐resolution PlanetScope satellite imagery to map interseasonal seagrass extent and quantify seascape metrics across 20 estuaries along a latitudinal gradient spanning 12° in NZ. We also explored the association of changes in seagrass metrics with satellite‐derived predictors such as sea surface temperature (SST), SST anomaly (SSTa), water column turbidity, and nutrient concentration. Our analyses revealed that NZ seagrass meadows varied in areal extent between years and seasons, but with no clear patterns over the 5‐year period, implying resilience to large‐scale stressors like the 2017/18 marine heatwave. Small‐scale patterns were also dynamic, for example, patch sizes and patch configurations differed across estuaries, seasons, and years. Furthermore, seagrass patches expanded in some estuaries with increasing SST and SSTa. These results highlight dynamic seagrass patterns that likely affect local processes such as biodiversity and carbon sequestration. Our analyses demonstrate that a combination of high‐resolution satellite remote sensing and seascape metrics is an efficient and novel approach to detect impacts from anthropogenic stressors, like eutrophication and climate changes, and climate extremes like cyclones and heatwaves.

Abstract A thermophilic pilot scale anaerobic digester treating chicken litter was subjected to pulse loads of ammonia of increasing concentration. A micro gas chromatograph (μ-GC) measured CO 2 , CH 4 , N 2 , H 2 and H 2 S in the biogas. In the liquid, NH 4 -N was measured manually, volatile fatty acids (VFA) were measured manually and with Near Infrared Spectroscopy (NIRS). Within the first 7–24 h after the pulse, the concentrations of iso-butyric and iso-valeric acid increased rapidly and were the best indicators of process stress due to ammonia pulses, confirmed by multivariate analysis. NIRS was not capable of accurate prediction of VFA iso-forms most likely due to low concentrations. Propionic acid was persistent. The ammonia pulses caused an overall decrease of biogas production. The biogas composition was not a good indicator of imbalances; little correlation with VFA measurements was observed.

317 children born and raised in two rural areas of Machakos District in Kenya were examined for enamel changes. All sources of drinking water were monitored for F–– over a period of 1 year.

Abstract Background From animal studies it is known that currently used pesticides can disturb thyroid function. Methods In the present study we investigated the thyroid function in 122 Danish greenhouse workers, to evaluate if greenhouse workers classified as highly exposed to pesticides experiences altered thyroid levels compared to greenhouse workers with lower exposure. Serum samples from the greenhouse workers were sampled both in the spring and the fall to evaluate if differences in pesticide use between seasons resulted in altered thyroid hormone levels. Results We found a moderate reduction of free thyroxine (FT4) (10–16%) among the persons working in greenhouses with a high spraying load both in samples collected in the spring and the fall, but none of the other measured thyroid hormones differed significantly between exposure groups in the cross-sectional comparisons. However, in longitudinal analysis of the individual thyroid hormone level between the spring and the fall, more pronounced differences where found with on average 32% higher thyroid stimulating hormone (TSH) level in the spring compared to the fall and at the same time a 5–9% lower total triiodthyroxin (TT3), free triiodthyroxine (FT3) and FT4. The difference between seasons was not consistently more pronounced in the group classified as high exposure compared to the low exposure groups. Conclusion The present study indicates that pesticide exposure among Danish greenhouse workers results in only minor disturbances of thyroid hormone levels.

The conversion of natural habitats into farmland has been a leading cause of species loss worldwide. Here, we investigated to what extent less intensive soil disturbance can mitigate this loss. Specifically, we examined whether reduced soil disturbance by tillage in agricultural fields could contribute to soil microbial biodiversity by providing a habitat for species that are limited by conventional tillage. To do so, we studied the diversity of soil biotas from three agricultural practices representing conventional tillage, reduced tillage and no tillage. Study fields were sampled by taking a bulk soil sample at the centre and edge of each field. The soil communities were recorded with environmental DNA metabarcoding using three molecular markers targeting bacteria, fungi and eukaryotes. While these three markers represent the vast majority of biotic variation in the soil, they will inevitably be dominated by the megadiverse microbiota of bacteria, microfungi and protists. We found a significant differentiation in community composition related to the intensity of tillage. Richness was weakly correlated to tillage, and more influenced by whether the sample was taken in the center or the edge of the field. Despite the significant effect of tillage on composition, comparisons with natural ecosystems revealed that all 30 study fields were much more similar in composition to other rotational fields than to more natural habitats, oldfields and leys. Despite a slightly higher similarity to oldfields and semi-natural grasslands, the contribution of no-till soil communities to biodiversity conservation is negligible, and our results indicate that restoration on set aside land may contribute more to conservation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13280-021-01611-0.

Noninversion tillage with tine- or disc-based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape, and maize in Europe. However, new regulations on pesticide use might hinder further expansion of reduced-tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programs based on integrated pest management (IPM) principles. Conventional noninversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher compared to plow-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in noninversion tillage systems, and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies, and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems, but their impact in noninversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes could become useful in reduced-tillage systems where more crop residues and less workable soils are more prevalent, but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced-tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research. Non-inversion tillage with tine or disc based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape and maize in Europe. However, new regulations on pesticide use may hinder further expansion of reduced tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programmes based on integrated pest management (IPM) principles. Conventional non-inversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher as compared to plough-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in non-inversion tillage systems and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems but their impact in non-inversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes may become useful in reduced tillage systems where more crop residues and less workable soils are more prevalent but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research.

Predicting post-fire ecosystem CO2 exchange requires an explicit understanding of the sensitivity of gross primary production (GPP), ecosystem respiration (ER) and net ecosystem exchange (NEE) to post-fire conditions. However, the simultaneous effects of fire on GPP, ER and NEE are rarely evaluated. We established a three-year manipulative fire experiment in a meadow grassland on the Tibetan Plateau to investigate the responses of GPP, ER and NEE to prescribed fire. We found that fire on average increased GPP by 13% and ER by 9%, leading to an increase in NEE by 20% across the three years. There was no clear relationship between post-fire changes in soil temperature and ecosystem CO2 exchange, yet reductions in soil volumetric moisture were positively related to changes in GPP, ER and NEE. These results suggest that post-fire stimulation of GPP, ER and NEE cannot be fully explained by changes in soil temperature and soil moisture. Besides, changes in GPP, ER and NEE were positively related to fire-induced increases in graminoid biomass, legume biomass and soil inorganic nitrogen. Taken together, our results suggest the interwoven control of biotic and abiotic factors on post-fire GPP, ER and NEE, yet also that shifts in plant functional type biomass may outweigh the negative effects of reduced soil moisture on ecosystem CO2 exchange. These results underscore how simultaneous documentation of GPP, ER and NEE dynamics can advance a mechanistic understanding of CO2 exchange under fire disturbance.