181 research outputs found

    Dynamical downscaling of CMIP5 1 Global Circulation Models over CORDEX-Africa with COSMO-CLM: evaluation over the present climate and analysis of the added value.

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    In this work we present the results of the application 8 of the Consor- tium for Small-scale Modeling (COSMO) Regional Climate Model (COSMO-CLM, hereafter, CCLM) over Africa in the context of the Coordinated Regional Climate Downscaling Experiment (CORDEX). An ensemble of climate change projections has been created by downscaling the simulations of four Global ClimateModels (GCM), namely:MPI-ESM-LR, HadGEM2- ES, CNRM-CM5, and EC-Earth. Here we compare the results of CCLM to those of the driving GCMs over the present climate, in order to investigate whether RCMs are effectively able to add value, at regional scale, to the performances of GCMs. It is found that, in general, the geographical distribution of mean sea level pressure, surface temperature and seasonal precipitation is strongly affected by the boundary conditions (i.e. driving GCMs), and seasonal statistics are not always improved by the downscaling. However, CCLM is generally able to better represent the annual cycle of precipitation, in particular over Southern Africa and the West Africa Monsoon (WAM) area. By performing a Singular Spectrum Analysis (SSA) it is found that CCLM is able to reproduce satisfactorily the annual and sub-annual principal components of the precipitation time series over the Guinea Gulf, whereas the GCMs are in general not able to simulate the bimodal distribution due to the passage of the WAM and show a unimodal precipitation annual cycle. Furthermore, it is shown that CCLM is able to better reproduce the Probability Distribution Function (PDF) of precipitation and some impact-relevant indices such as the number of consecutive wet and dry days, and the frequency of heavy rain events.JRC.H.7-Climate Risk Managemen

    Hur tar sig storvilt fram i landskapet? - En utredning av den biologiska infrastrukturen för storvilt mellan grönområdena i Borås Stad

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    The infrastructure and the traffic that it brings affect wild animals and thus the entire biodiversity. The human built up network of cities and connecting roads are major barriers for many species in the natural world, making it harder for them to move through the landscape. The more roads in a landscape, the more fragmented it gets and with it important habitats get degraded. Long-term effects from barriers can even have ecological consequences. Ultimately, barriers in the landscape can negatively affect the genetic exchange in different populations if it totally prevents gene flow between the populations. This study is about how green areas are connected in the city of Borås, and where the existing possibilities are for larger wildlife to get through or around the city of Borås, using these green areas and wildlife passages. I also try to find out where there are possibilities for a better connectivity between the greener areas in and around Borås city. There is a relatively good connectivity between the larger nature reserves in the northern part of Borås, but in the eastern, western and southern parts the national highway 40 is a serious barrier. To make the connectivity better in the surrounding landscape it would be of interest to build wildlife passages to make it easier for wildlife to pass this barrier without ending up in the city. Still, more information is needed about the wildlife fencing before more precise suggestions for fauna passages can be made – for example a map clearly displaying all the existing wildlife fencing

    Future Forests Årsrapport 2015

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    Effekten på artrikedom av kärlväxter vid gödsling av betesmarker

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    The major cause of the impoverishment of biological diversity in Sweden is the modernization of farming and forestry. Natural grasslands have high biodiversity and many important ecosystem services are based on biodiversity. The area of grasslands in Sweden has decreased by 70% since the late 1800s. Numerous species of vascular plants are dependent on grasslands that are unfertilized and grazed continuously by grazing animals. This study compares four grasslands; two of them have been fertilized and the other two have not. These grasslands are located in Häglinge community, which belongs to Hässleholms municipality. Inventoried vascular plants in those grasslands are estimated in a three-point scale to obtain the frequency of vascular plant species occurrence and soil samples were taken from each area to determinate the pH levels. Also, the landowners were interviewed to obtain information about the way they treat those grasslands. The results from the study show that more species of vascular plants were found on unfertilized grazing areas. More favor nitrogen species of vascular plants, were found on the fertilized grasslands. The unfertilized grasslands have more species of vascular plant with higher frequency compared to the fertilized grasslands. Calculations of ordination shows that the species composition of vascular plants is similar for the fertilized grasslands, and also the species composition of vascular plants on the unfertilized pastures are similar. No relationship between pH-levels, species composition of vascular plants and fertilization could be obtained. The study also shows the possibility to restore the grazing areas that had been fertilized and how to protect the unfertilized grazing areas.Emma Eckberg Effekten på artrikedom av kärlväxter vid gödsling av betesmarker I Sverige är den största orsaken till utarmningen av biologisk mångfald det moderna skogs- och jordbruket som förstör livsmiljöer för många arter. Arealen betesmark i Sverige har minskat med över 70 % sedan slutet av 1800-talet. Bevarade betesmarker hyser en hög biologisk mångfald och flera ekosystemtjänster. Många kärlväxtarter kan endast etablera sig på ogödslade betesmarker. Ogödslade betesmarker är därmed avgörande för många kärlväxters fortlevnad. Hur ser egentligen skillnaden ut i artrikedom av kärlväxter och markens pH-värde mellan gödslade- och icke gödslade betesmarker? Vilka åtgärder krävs för att restaurera, sköta och bevara betesmarker? Studien jämför fyra betesmarker, varav två av dem är gödslingspåverkade och två av dem är icke gödslingspåverkade belägna i Häglinge församling. Häglinge församling som tillhör Hässleholms kommun, karakteriseras av ett småkulligt mosaikartat jordbrukslandskap. Där finns både välhävdade och ogödslade betesmarker samt betesmarker där hävden har upphört och/eller är gödslingspåverkade. Inventerade kärlväxtarter på de valda betesmarkerna skattades i en tre-gradig skala enligt BINV02103, vilket gav ett kvalitativt mått på kärlväxtarternas frekvens och en arts vanlighet och förekomst i ett område. Två provrutor, 0.25 m2, placerades på varje betesmark på platser som karakteriserar betesmarken. Inom provrutorna genomfördes en täckningsgrad enligt BINV01903. Markernas pH-värde mättes för två jordprov från varje betesmark. Markägarna för respektive betesmark intervjuades för att få information om markanvändningen. Resultatet från studien visar att fler arter av kärlväxter fanns vid de ogödslade betesmarkerna. Mer kvävegynnade arter fanns vid de gödslade betesmarkerna. De ogödslade betesmarkerna har fler kärlväxtarter med högre frekvens i jämförelse med de gödslade betesmarkerna. Beräkningar av ordination visar att artsammansättningen av kärlväxter är likartad för de ogödslade betesmarkerna och likaså är artsammansättningen likartad vid de gödslade betesmarkerna. Shannons diversitetsindex var högst vid en av de ogödslade betesmarkerna och lägst vid de gödslade betesmarkerna. Inget samband mellan markernas pH-värde, artsammansättningen av kärlväxtarter och gödsling kunde fås fram. Studien diskuterar möjligheten att restaurera markerna som har blivit gödslade och hur markerna som inte har blivit gödslade lämpligast ska fortsätta skötas och bevaras. Handledare: Eva Waldermarson Examensarbete 15 hp i MVEK02 2015 Biologiska institutionen, Lunds universite
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