25 research outputs found
Forest canopy mitigates soil N2O emission during hot moments
Riparian forests are known as hot spots of nitrogen cycling in landscapes. Climate warming speeds up the cycle. Here we present results from a multi-annual high temporal-frequency study of soil, stem, and ecosystem (eddy covariance) fluxes of N2O from a typical riparian forest in Europe. Hot moments (extreme events of N2O emission) lasted a quarter of the study period but contributed more than half of soil fluxes. We demonstrate that high soil emissions of N2O do not escape the ecosystem but are processed in the canopy. Rapid water content change across intermediate soil moisture was a major determinant of elevated soil emissions in spring. The freeze-thaw period is another hot moment. However, according to the eddy covariance measurements, the riparian forest is a modest source of N2O. We propose photochemical reactions and dissolution in canopy-space water as reduction mechanisms.Peer reviewe
Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits
Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing population genetic structure at different spatial scales is thus a crucial step towards understanding mechanisms underlying intraspecific differentiation and diversification. Here, we studied the population genetic structure of a highly mobile species â the great tit Parus major â at different spatial scales. We analysed 884 individuals from 30 sites across Europe including 10 close-by sites (< 50 km), using 22 microsatellite markers. Overall we found a low but significant genetic differentiation among sites (FST = 0.008). Genetic differentiation was higher, and genetic diversity lower, in south-western Europe. These regional differences were statistically best explained by winter temperature. Overall, our results suggest that great tits form a single patchy metapopulation across Europe, in which genetic differentiation is independent of geographical distance and gene flow may be regulated by environmental factors via movements related to winter severity. This might have important implications for the evolutionary trajectories of sub-populations, especially in the context of climate change, and calls for future investigations of local differences in costs and benefits of philopatry at large scales
Global patterns in endemicity and vulnerability of soil fungi
Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms
Risk analysis of global warming-induced greenhouse gas emissions from natural sources
10th International Conference on Risk Analysis, , , -International audienceThe increase in the emissions of greenhouse gases (GHG) CO 2 , CH 4 , and N 2 O is the most important factor causing global warming. Natural sources make up about 96%, 46%, and 64% of total emissions of the three gases, respectively. Relatively small man-made CO 2 fluxes, together with CH 4 and N 2 O (with a radiative force 34 and 298 times higher than that of CO 2 , respectively) upset the natural balance of the carbon (C) cycle and create an artificial forcing of global temperatures which is warming the planet. However, even after stopping all anthropogenic CO 2 emissions, the warming-induced GHG from natural sources will cause an on-going temperature increase and many resulting environmental problems. Based on literature, we analyse the potential change in GHG emissions from the main natural sources, which are influenced by the effects of global warming. Since there are various uncertainties in the estimations of terrestrial-atmosphere and ocean-atmosphere CO 2 exchange, this most important factor remains un-predicted and needs significantly more investigation of the ability of oceans and terrestrial ecosystems to absorb CO 2 . Both CH 4 and N 2 O emissions may continue to increase. The thawing of CH 4 hydrates in the ocean shelf and in permafrost regions is the largest long-term threat for global warming, but even now rising temperature will enhance emissions from wetlands, lakes, vegetation and even upland soils, due to an increasing threat of wildfires. Changes in hydrological regime are the main driving force for N 2 O emissions
Engineering-out hazards: digitising the management working safety in confined spaces
Purpose: This paper aims to report upon the further development of a hybrid application programming interface (API) plug-in to building information modelling (BIM) entitled confined spaces safety monitoring system âCoSMoSâ. Originally designed to engineer-out environmental hazards associated with working in a buildingâs confined spaces (during the construction phase of a buildingâs life-cycle), this second generation version is expanded upon to use archival records to proactively learn from data generated within a sensor network during the buildingâs operations and maintenance (O&M) phase of asset management (AM). Design/methodology/approach: An applied research methodological approach adopted used a two-phase process. In phase one, a conceptual model was created to provide a âblueprint mapâ to integrate BIM, sensor-based networks and data analytics (DA) into one integral system. A literature review provided the basis for the conceptual modelâs further development. In phase two, the conceptual model was transposed into the prototypeâs development environment as a proof of concept using primary data accrued from a large educational building. Findings: An amalgamation of BIM, historical sensor data accrued and the application of DA demonstrate that CoSMoS provides an opportunity for the facilities management (FM) team to monitor pertinent environmental conditions and human behaviour within buildings that may impact upon occupant/worker safety. Although working in confined spaces is used to demonstrate the inherent potential of CoSMoS, the system could readily be expanded to analyse sensor-based networkâs historical data of other areas of building performance, maintenance and safety. Originality/value: This novel prototype has automated safety applications for FM during the asset lifecycle and maintenance phase of a buildingâs O&M phase of AM. Future work is proposed in several key areas, namely, develop instantaneous indicators of current safety performance within a building; and develop lead indicators of future safety performance of buildings
Jaunakas tendences kvalitativas partikas razosana Starptautiska zinatniski-praktiska konference: Referati
Table of contents and abstracts in EnglishAvailable from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi