Search results for "33"
showing 10 items of 1917 documents
Pest management under climate change: The importance of understanding tritrophic relations.
2018
11 pages; International audience; Plants and insects depend on climatic factors (temperature, solar radiation, precipitations, relative humidity and CO2) for their development. Current knowledge suggests that climate change can alter plants and insects development and affect their interactions. Shifts in tritrophic relations are of particular concern for Integrated Pest Management (IPM), because responses at the highest trophic level (natural enemies) are highly sensitive to warmer temperature. It is expected that natural enemies could benefit from better conditions for their development in northern latitudes and IPM could be facilitated by a longer period of overlap. This may not be the ca…
Long-term mineral fertiliser use and maize residue incorporation do not compensate for carbon and nutrient losses from a Ferralsol under continuous m…
2015
9 pages; International audience; It has been repeatedly argued that mineral fertiliser application combined with in situ retention of crop residue biomass can sustain long-term productivity of West African soils. Using 20-year experimental data from southern Togo, a biannual rainfall area, we analysed the effect of two rates of mineral NPK fertiliser application to maize–cotton rotation on the long-term dynamics of soil C and nutrient contents, as compared with two control treatments. Mineral fertiliser treatments consisted of application to both maize (first season) and cotton (second season) the research-recommended NPK rates (Fertiliser-RR) and 1.5 times these rates (Fertiliser-1.5 RR). …
Thirty years unmanaged green roofs: Ecological research and design implications
2016
Abstract The variations in species composition and assemblage of unmanaged simple-intensive green roofs in Hannover, Germany, were investigated over a thirty year period, in order to assess the persistence of the initial seed mixture and to evaluate floristic changes. The roofs were greened in 1985 with soil-based turf rolls sown with a mixture of five grasses (Festuca rubra, Festuca ovina, Agrostis capillaris, Lolium perenne and Poa pratensis). Three sets of 120 phytosociological releves, sampled in 1987, 1999 and 2014, have been compared to assess: (1) nestedness vs spatial turnover, (2) functional diversity and (3) the importance of vegetation dynamics on green roof performance and desig…
Plant functional and taxonomic diversity in European grasslands along climatic gradients
2021
Aim European grassland communities are highly diverse, but patterns and drivers of their continental-scale diversity remain elusive. This study analyses taxonomic and functional richness in European grasslands along continental-scale temperature and precipitation gradients. Location Europe. Methods We quantified functional and taxonomic richness of 55,748 vegetation plots. Six plant traits, related to resource acquisition and conservation, were analysed to describe plant community functional composition. Using a null-model approach we derived functional richness effect sizes that indicate higher or lower diversity than expected given the taxonomic richness. We assessed the variation in abso…
GeneSys-Beet: A model of the effects of cropping systems on gene flow between sugar beet and weed beet
2008
A weedy form of the genus Beta, i.e. Beta vulgaris ssp. vulgaris (hence ''weed beet'') frequently found in sugar beet is impossible to eliminate with herbicides because of its genetic proximity to the crop. It is presumed to be the progeny of accidental hybrids between sugar beet (ssp. vulgaris) and wild beet (ssp. maritima), or of sugar beet varieties sensitive to vernalization and sown early in years with late cold spells. In this context, genetically modified (GM) sugar beet varieties tolerant to non-selective herbicides would be interesting to manage weed beet. However, because of the proximity of the weed to the crop, it is highly probable that the herbicide-tolerance transgene would b…
Out in the open : behavior’s effect on predation risk and thermoregulation by aposematic caterpillars
2020
Abstract Warning coloration should be under strong stabilizing selection but often displays considerable intraspecific variation. Opposing selection on color by predators and temperature is one potential explanation for this seeming paradox. Despite the importance of behavior for both predator avoidance and thermoregulation, its role in mediating selection by predators and temperature on warning coloration has received little attention. Wood tiger moth caterpillars, Arctia plantaginis, have aposematic coloration, an orange patch on the black body. The size of the orange patch varies considerably: individuals with larger patches are safer from predators, but having a small patch is beneficia…
Regulating blockchain for sustainability? The critical relationship between digital innovation, regulation, and electricity governance
2021
Abstract Blockchain technology has found several innovative applications in the electricity industry. However, its potential has still to be discovered. This is partly due to the role that regulation plays in electricity markets. To be introduced, experimented with, and eventually adopted on a commercial scale, blockchain-supported innovations need to fit the existing regulatory framework or the rules to be reshaped or updated. We focus on energy regulators' possible responses to the blockchain-enhanced market operations (both from the incumbents and potential newcomers), suggesting a monitoring mechanism that can support innovation.
Analysis of some renewable energy uses and demand side measures for hotels on small Mediterranean islands: A case study
2018
Abstract Tourist activity strongly influences the energy consumption and the overall load profile of communities with isolated energy systems. One example is hotel sectors on small islands that are not connected to mainland energy distribution grids. The use of solar energy systems could be a smart option for reducing energy consumption and tackling seasonal fluctuation. The operation of a weak and isolated electric grid requires attention to the management of power profiles in very short time frames. Energy storage (thermal or electric), as well as building automation control technologies, can be utilised for these aims. In this context, the present paper illustrates a study conducted at a…
Technical Rules for Connecting PV Systems to the Distribution Grid: A Critical Comparison of the Italian and Vietnamese Frameworks
2018
In the last two decades, starting from the Kyoto protocol, decarbonization has promoted worldwide the rise of distributed generation from renewable energy sources. Currently, Vietnam is still showing a strong dependence on fossil fuels but with a great interest in investing in renewable, especially in photovoltaic (PV) systems. In this paper, the current Vietnamese technical and administrative framework for the connection of PV systems to the power grid is presented and critically compared to the Italian one, in order to define the bases for future cooperation in distributed generation and renewable sectors.
Economic feasibility of stationary electrochemical storages for electric bill management applications: The Italian scenario
2016
Battery energy storage systems (BESSs) are expected to become a fundamental element of the electricity infrastructure, thanks to their ability to decouple generation and demand over time. BESSs can also be used to store electricity during low-price hours, when the demand is low, and to meet the demand during peak hours, thus leading to savings for the consumer. This work focuses on the economic viability of BESS from the point of view of the electricity customer. The analysis refers to a lithium-ion (Li-ion), an advanced lead-acid, a zinc-based, a sodium-sulphur (NaS) and a flow battery. The total investment and replacement costs are estimated in order to calculate the cumulated cash flow, …