Suchergebnisse

27 Pags.- 10 Figs.- 7 Tabls. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). ; Mediterranean-climate catchments are characterized by significant spatial and temporal hydrological variability caused by the interaction of natural as well human-induced abiotic and biotic factors. This study investigates the non-linearity of rainfall-runoff relationship at multiple temporal scales in representative small Mediterranean-climate catchments (i.e., <10 km2) to achieve a better understanding of their hydrological response. The rainfall-runoff relationship was evaluated in 43 catchments at annual and event—203 events in 12 of these 43 catchments—scales. A linear rainfall-runoff relationship was observed at an annual scale, with a higher scatter in pervious (R2: 0.47) than impervious catchments (R2: 0.82). Larger scattering was observed at the event scale, although pervious lithology and agricultural land use promoted significant rainfall-runoff linear relations in winter and spring. These relationships were particularly analysed during five hydrological years in the Es Fangar catchment (3.35 km2; Mallorca, Spain) as a temporal downscaling to assess the intra-annual variability, elucidating whether antecedent wetness conditions played a significant role in runoff generation. The assessment of rainfall-runoff relationships under contrasted lithology, land use and seasonality is a useful approach to improve the hydrological modelling of global change scenarios in small catchments where the linearity and non-linearity of the hydrological response—at multiple temporal scales—can inherently co-exist in Mediterranean-climate catchments. ; This work was supported by the research project CGL2017-88200-R "Functional hydrological and sediment connectivity at Mediterranean catchments: global change scenarios –MEDhyCON2" funded by the Spanish Ministry of Science, Innovation and Universities, the Spanish Agency of Research (AEI) and the European Regional Development Funds (ERDF). The contribution of Jérôme Latron was supported by the research project PCIN-2017-061/AEI also funded by the Spanish Government. Josep Fortesa has a contract funded by the Ministry of Innovation, Research and Tourism of the Autonomous Government of the Balearic Islands (FPI/2048/2017). Julián García-Comendador is in receipt of a pre-doctoral contract (FPU15/05239) funded by the Spanish Ministry of Education, Culture and Sport. Miquel Tomàs-Burguera acknowledges the support from the project CGL2017-83866-C3-3-R financed by the European Regional Development Funds (ERDF) and the Spanish Ministry of Science, Innovation and Universities. Jaume Company is in receipt of Young Qualified Program fund by Employment Service of the Balearic Islands and European Social Fund (SJ-QSP 48/19). Aleix Calsamiglia acknowledges the support from the Spanish Ministry of Science, Innovation and Universities through a pre-doctoral contract (BES-2013-062887). ; Peer reviewed

The recently adopted UN Sustainable Development Goals (SDGs) encompasses a specific goal forwater (SDG-6). The target 6.4 deals with water scarcity and refers to two main indicators: water use efficiency and water stress (WS), monitored by the UN statistical services yearly at the country level. Yet, for more efficient development planning, indicators should also be provided with higher spatial and temporal resolutions. This study presents a data-driven method allowing to disaggregate the WS indicator at higher spatial and temporal resolution. We applied the method for the Medjerda catchment in Tunisia, known as being severely water-stressed. We disaggregated theWS indicator fromthe overall catchment to the administrative regional level at yearly and monthly scales. In order to overcome poorly documented irrigation water withdrawals, two approaches were adopted: 1)we used yearly governmental data at both catchment and regions scales; 2)we replaced governmental irrigation data by remote sensing-based irrigation estimation. First Order Uncertainty Analysis (FOUA)was performed to characterize the uncertainty associated with the assessment ofWS. Results reveal that theWS at the scale of the catchment increases considerably in recent years, exceeding 50% from2005 and surpassing the 100% threshold in 2015 and 2016 (102%, 108% respectively). The two adopted approaches result in similar WS trends. However, the second approach yields higherWS values compared to the first approach (144% versus 108% in 2016). Themonthly-disaggregatedWSat catchment scale exhibits a similar increasing trend. The highestWSvalues are at the end of the fall and during the summer season,which ismainly due to the increasing demand for irrigation and drinking water. Siliana region is the most affected byWS, while Beja is the least affected. The FOUA shows that the integration of remote sensing-based irrigation data reduces theWS uncertainty.

The recently adopted UN Sustainable Development Goals (SDGs) encompasses a specific goal forwater (SDG-6). The target 6.4 deals with water scarcity and refers to two main indicators: water use efficiency and water stress (WS), monitored by the UN statistical services yearly at the country level. Yet, for more efficient development planning, indicators should also be provided with higher spatial and temporal resolutions. This study presents a data-driven method allowing to disaggregate the WS indicator at higher spatial and temporal resolution. We applied the method for the Medjerda catchment in Tunisia, known as being severely water-stressed. We disaggregated theWS indicator fromthe overall catchment to the administrative regional level at yearly and monthly scales. In order to overcome poorly documented irrigation water withdrawals, two approaches were adopted: 1)we used yearly governmental data at both catchment and regions scales; 2)we replaced governmental irrigation data by remote sensing-based irrigation estimation. First Order Uncertainty Analysis (FOUA)was performed to characterize the uncertainty associated with the assessment ofWS. Results reveal that theWS at the scale of the catchment increases considerably in recent years, exceeding 50% from2005 and surpassing the 100% threshold in 2015 and 2016 (102%, 108% respectively). The two adopted approaches result in similar WS trends. However, the second approach yields higherWS values compared to the first approach (144% versus 108% in 2016). Themonthly-disaggregatedWSat catchment scale exhibits a similar increasing trend. The highestWSvalues are at the end of the fall and during the summer season,which ismainly due to the increasing demand for irrigation and drinking water. Siliana region is the most affected byWS, while Beja is the least affected. The FOUA shows that the integration of remote sensing-based irrigation data reduces theWS uncertainty.

Event attribution, which determines how anthropogenic climate change has affected the likelihood of certain types of extreme events, is of broad interest to industries, governments, and the public. Attribution results can be highly dependent on the definition of the event and the characteristics assessed, which are part of framing the attribution question. Despite a widely acknowledged sensitivity to framing, little work has been done to document the impacts on attribution and the resulting implications. Here, we use a perfect‐model approach and large ensembles of coupled climate‐model simulations to demonstrate how event attribution depends on the spatial and temporal scales used to define the event. In general, stronger attribution is found for events defined over longer time scales and larger spatial scales due to enhanced signal‐to‐noise ratios. With strong warming trends, most regions see large changes in the likelihood of temperature extremes at all scales, even at low levels of global mean temperature increase. For precipitation extremes, spatial scale plays a strong role. It may be possible to attribute changes in likelihood for extreme precipitation events defined over larger scales, but greater levels of global warming are often required before it is possible to attribute changes in the likelihood of smaller‐scale precipitation events. Care must be taken to understand the scales used in event attribution, in order to properly understand the results. ; ISSN:2328-4277

The authors in this volume make a case for LTSER's potential in providing insights, knowledge and experience necessary for a sustainability transition. This expertly edited selection of contributions from Europe and North America reviews the development of LTSER since its inception and assesses its current state, which has evolved to recognize the value of formulating solutions to the host of ecological threats we face. Through many case studies, this book gives the reader a greater sense of where we are and what still needs to be done to engage in and make meaning from long-term, place-based and cross-disciplinary engagements with socio-ecological systems

Mushrooms are important non-wood-forest-products in many Mediterranean ecosystems, being highly vulnerable to climate change. However, the ecological scales of variation of mushroom productivity and diversity, and climate dependence has been usually overlooked due to a lack of available data. We determined the spatio-temporal variability of epigeous sporocarps and the climatic factors driving their fruiting to plan future sustainable management of wild mushrooms production. We collected fruiting bodies in Pinus sylvestris stands along an elevation gradient for 8 consecutive years. Overall, sporocarp biomass was mainly dependent on inter-annual variations, whereas richness was more spatial-scale dependent. Elevation was not significant, but there were clear elevational differences in biomass and richness patterns between ectomycorrhizal and saprotrophic guilds. The main driver of variation was late-summer-early-autumn precipitation. Thus, different scale processes (inter-annual vs. spatial-scale) drive sporocarp biomass and diversity patterns; temporal effects for biomass and ectomycorrhizal fungi vs. spatial scale for diversity and saprotrophic fungi. The significant role of precipitation across fungal guilds and spatio-temporal scales indicates that it is a limiting resource controlling sporocarp production and diversity in Mediterranean regions. The high spatial and temporal variability of mushrooms emphasize the need for long-term datasets of multiple spatial points to effectively characterize fungal fruiting patterns. ; This study was funded by the Spanish research projects AGL2012-40035-C03-01 and AGL2015-66001-C3-1-R (MEC Spain) and by the European project StarTree (No. 311919). JGA was supported by Juan de la Cierva-fellowship (IJCI-2014-21393) and DYMECO project and SdM by the European Union's Horizon 2020 MultiFUNGtionality Marie Skłodowska-Curie (IF-EF No. 655815) and JAB benefit from Serra-Hunter Fellow provided by the Generalitat of Catalunya.

The brown marmorated stink bug, Halyomorpha halys (Stål), is native to eastern Asia and is presently invading North America. Little is known about the exposure to and effects of winter temperatures in newly invaded regions on H. halys. The overwintering habitats that this species utilizes vary greatly in their thermal buffering capacity. They naturally overwinter in aggregations beneath loose bark on trees and in cliff outcroppings, but will also commonly aggregate in buildings. Effects of cold temperatures such as mortality and freezing have yet to be quantified in the invading population. We report that H. halys is chill intolerant (i.e., dies before reaching its freezing point), and that the degree of cold tolerance of populations in North America differs by season, sex, and acclimation location. The mean winter supercooling point (+/- SEM) of individuals acclimated in Minnesota was -17.06A degrees C A +/- 0.13 and in Virginia was -13.90A degrees C A +/- 0.09. By using laboratory assays of lower lethal temperatures and ambient air temperature records, we accurately forecasted mortality for field experiments in Minnesota and Virginia. Temperature refugia provided by human-built structures are likely crucial for overwintering survival during atypically cold winters and possibly contribute to the northern geographic range expansion of this economically damaging insect in the temperate climates of North America. ; Minnesota's Discovery, Research, and InnoVation Economy (MnDRIVE) Global Food Ventures graduate fellowship at the University of Minnesota; United States Department of Agriculture National Institute of Food and Agriculture Specialty Crop Research Initiative (USDA-NIFA-SCRI) Grant [2011-51181-30937]; Virginia Department of Agriculture and Consumer Services United States Department of Agriculture Specialty Crop Block Grant ; This project would not have been possible without the dedication of several people, especially Eric Burkness, Lindsey Christianson, Amy Morey, Robert Koch, Katherine Kamminga, Tracy Leskey, and Doo-Hyung Lee, as well as Jaana Iverson, Benjamin Aigner, and Ashley Lohr. We thank Nathaniel Cira for reviewing this paper prior to submission. We also appreciate the use of the laboratory facilities of the United States Department of Agriculture Forest Service Northern Research Station. This project was funded in part by a Minnesota's Discovery, Research, and InnoVation Economy (MnDRIVE) Global Food Ventures graduate fellowship at the University of Minnesota, United States Department of Agriculture National Institute of Food and Agriculture Specialty Crop Research Initiative (USDA-NIFA-SCRI) Grant 2011-51181-30937, and the Virginia Department of Agriculture and Consumer Services United States Department of Agriculture Specialty Crop Block Grant for the 2011 fiscal year. ; Public domain authored by a U.S. government employee