<p>Abstract</p><p> </p><p>The benthic macroinvertebrate fauna of 22 natural springs on Öland was sampled, by using a time-standarized kick/sweep sampling technique, in the end of September and early October. The aim was to determine the number of species and their abundances in the macroinvertebrate communities in springs and how/why these may change between different springs. Likewise there was a purpose to investigate possible differences between springs considering the proportions of the number of species and the abundances of the five functional feeding groups; shredders, collectors, filter-feeders, scrapers and predators. There was also an aim to investigate if the distances betweeen springs had any influence on similarity between the communities of benthic macroinvertebrates of the springs. Analysis from the springs collected material showed several interesting patterns in the number of species and their abundances when compared between springs devided into groups depending on their environmental factors such as depth and pH. Equally interesting patterns where found in the proportions of the number of species and their abundances of the functional feeding groups between different groups of springs with different environmental features such as size, depth and type of surrounding area. Results also showed that springs separated by shorter distances had a higher likeness between their communities of benthic macroinvertebrates then springs separated by greater distances.</p>

<p>Studies on laboratory animals suggest that developing and newborn mammals are more vulnerable than the adults with respect to the harmful effects of organochlorine (OC) pollutants such polychlorinated biphenyls (PCBs) and OC pesticides (Brouwer et al. 1995; 1998a; Colborn 2004). These effects include neurobiological and neurochemical effects, reproductive effects, reduced brain and circulatory thyroid hormone levels, impaired immune functions and vitamin A homeostasis (Brouwer et al. 1995; Colborn 2004; Safe et al. 1994; Tryphonas 1994). In humans, several of these negative effects of OCs have been reported in children of mothers with high pollutant burdens (Jacobson and Jacobson 1996, 1997; Koopman-Esseboom et al. 1994; Sandau et al. 2002; ten Tusscher et al 2003; Weisglas- Kuperus et al. 2000, 2004). Most organochlorines are highly lipophilic and resistant against degradation, and biomagnify as a function of the trophic level in food webs. Due to long food chains and the lipid richness of marine ecosystems, marine apex predators, such as seals, often accumulate very high burdens of these compounds (Aquilar et al. 2002), exemplifying the particular concern about toxic effects in these species. Studies of newborn phocid seals may be particularly interesting, because seals have lipid rich milk, resulting in the nursed grey seal pups being exposed to relatively high concentrations of OCs (Addison and Brodie 1977, 1987: Addison et al. 1999; Debier et al. 2003; Green et al. 1996; Pomeroy et al. 1996; Schweigert and Stobo 1994) during a period of their life when their endocrine and neural systems are still under development, and under the influence of the potentially disruptive properties of these pollutants (Hall et al. 1998; Simms et al. 2000b).</p><p>Particularly high concentrations of OCs have been found in seals from the Baltic Sea as compared to seals from the North-Atlantic Ocean (Jenssen 1996; Nyman et al. 2002), and it has been suggested that these high exposure levels severely affects the health of Baltic seals (Bergman 1999; Bergman et al. 2001; Helle et al. 1976a,b; Nyman et al. 2001, 2003; Olsson et al. 1994). Given that the developing mammal might be particularly susceptible to the effects of OCs, it is of special interest to examine possible OC related effects that newborn seals may suffer from. Results from such a study may also predict the effects of OCs on marine mammals in general and possibly on humans (Jenssen 2003).</p> / Paper I and paper IV are reprinted with kind permission of Elsevier, sciencedirect.com

<p>Temporal and spatial variation in the environment can influence the performance of individuals in wild ungulate populations. Of particular importance is an understanding of the mechanisms that shape variation in individual body mass, because several important life history traits are directly related to body mass. Body mass is one of the first traits that is influenced by environmental variation, and often the effect operates through variation in the components of the foraging niche of ungulates. In this thesis, I aim to demonstrate how measurements of environmental variation relate to variation in the foraging niche of ungulates. Furthermore, I aim to explore how variation in ungulate life history traits relates to these variables, and finally, how the management of ungulates could benefit from the incorporation of knowledge about the effects of environmental variation on population dynamics. I use weather observations, large-scale climate indices, and indices of environmental phenology based on satellite-derived vegetation indices (NDVI) to analyse the effect of environmental variation on plants and body mass in moose (<i>Alces alces</i>) and roe deer (<i>Capreolus capreolus</i>) populations. </p><p>The environmental variables that explained most of the variation in plant performance, measured as radial growth in common juniper (<i>Juniper communis</i>) also explained variation in ungulate body mass. These variables were related to conditions in spring and early summer. Plant growth was low in cold summers, and in spring where the green-up curve as measured by change in photosynthetic activity during spring was moderate. Such growing conditions are recognised to increase the quality of the plants as forage for ungulates. Consequently, moose body mass in autumn showed the opposite pattern than juniper to environmental conditions, indicating that quality of plants, rather than the quantity, is an important component in temperate ungulate foraging niche. Further, regional variation in moose body mass was associated with environmental variables related to forage quality. Roe deer body mass was associated with availability of forage during winter, and not with factors related to summer conditions. Factors related to forage quantity neither influenced temporal nor spatial variation in body mass in the two species. </p><p>Accordingly, it appears that both weather observations and satellite-derived vegetation indices are able to effectively predict variation in plant performance related to variation in foraging conditions for ungulates. The variation in forage quality in space and time created variation in body mass between populations and between cohorts within a population. Further, the variation in body mass between moose population, caused by variation in the foraging conditions, predicted how the populations differentially respond to the effects of environmental stochastisity. In populations with a high mean body mass, or a low density relative to plant biomass production, available resources buffered environmental stochastisity, and were less influenced by environmental variation than populations with relatively fewer resources available. </p><p>If wildlife managers fail to incorporate the effects of environmental variation on population performance, e.g. on the recruitment rate, the population may show unexpected and large fluctuations in size. Therefore, managers should attempt to incorporate knowledge of recent environmental conditions on the population when setting harvesting quotas. </p><p>In face of the large variation in environmental conditions experienced by the ungulate populations in Norway, and the fact that responses to environmental variation varies between populations, management should be regionally adapted, and aim to incorporate variation in vital rates caused by environmental conditions. This is likely to create more stable and predictable populations. In face of the predicted climate and landscape changes in Norwegian forests, environmental variables, e.g. from satellite-derived vegetation indices, have the potential to be a powerful tool for a sustainable management of ungulate populations. Consequently, such information should be incorporated into the management of ungulates in order to a) obtain a management of ungulate populations that is adapted to regional mechanisms of environmental variation, and b) acquire a management that is sustainable in face of future change in climate and landscape that may vary regionally. This calls for a regional differentiation in management strategies.</p>

<p>In the present thesis, levels of polychlorinated biphenyls (PCBs), some chosen organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) were analyzed by gas chromatography in the yolk sac of newly hatched chicks of European shag (<i>Phalacrocorax aristotelis</i>), kittiwake (<i>Rissa tridactyla</i>), Brünnich’s guillemot (<i>Uria lomvia</i>) and common eider (<i>Somateria mollissima</i>) from the Norwegian coast and Svalbard. Levels of vitamin A (retinol), retinyl palmitate and vitamin E (α-tocopherol) were measured in plasma and liver of the hatchlings using high-performance liquid chromatography (HPLC). Using statistics, possible significant relationships between levels of the persistent organic pollutants (POPs) and vitamin levels were examined. Hence, the study aimed to elucidate retinoids and tocopherol as potential biomarkers of POP exposure. An exposure study on domestic duck (<i>Anas platyrhynchos</i>) eggs was also conducted to assess the effects of 2,2’,4,4’,5-pentabromodiphenyl ether (PBDE-99) on vitamin levels under controlled laboratory conditions.</p><p>There were significant differences in POP levels between the bird species included in the present study. In general, kittiwake hatchlings had higher levels of POPs than the other species, followed by shag, Brünnich’s guillemot and common eider hatchlings. Levels of organochlorine compounds in the hatchlings seemed to be higher than reported in sea bird eggs from the Canadian Arctic but lower than reported in eggs of other seabirds from the Netherlands, the Baltic, the Great Lakes and Japan. In contrast to this, the levels of PBDEs and HBCD seemed to be high in some of the species (kittiwakes, shags) relative to a European scale.</p><p>Negative relationships were revealed between POPs and morphology in Brünnich’s guillemot hatchlings, indicating that this species may be more responsive with respect to effects of POPs on morphological variables than the other species included in the present study. The importance of considering possible confounding impacts of lipid content when studying effects of POPs on morphological variables was emphasized in shag hatchlings. </p><p>The study revealed negative correlations between POPs and liver tocopherol levels in domestic duck and shag hatchlings. In Brünnich’s guillemot hatchlings, liver tocopherol levels also were negatively associated with POPs, but the relationships were less strong when the effect of body mass on tocopherol levels was accounted for. In kittiwake and common eider hatchlings, however, there seemed to be a positive influence by POPs on tocopherol levels. Thus, the results should encourage further research on the effects of POPs on tocopherol levels (including oxidized forms of the vitamin).</p><p>In shag hatchlings, negative relationships between POPs and plasma retinol levels were observed, in line with several previous studies on birds. Since retinol was not influenced in any other species included in the study, tocopherol levels might be more responsive than retinol levels to POP exposure. Additional studies should, however, be conducted before certain conclusions are drawn.</p><p>Concerning the work needed for further development of vitamins as biomarkers of POP, effort should be done to characterize confounding factors, such as diet and condition of the avian mothers. Although there was no obvious link between the observed responses of vitamins to POP exposure and effects at higher biological levels (i.e. reproduction disturbances, population decline), the relevance of vitamins as potential biomarkers of POP exposure should not be repelled.</p>

<p>Lake Bornsjön is situated 30 km southwest of Stockholm in a rift valley lake and consist three basins outstretched in northwest-southeast direction. The surface area is 6,7 km2 with a maximum depth of 18,3 meters, a mean depth of 9,8 meters and a retention time of the water of 6,5 years. The drainage area is 42 km2 and consists mainly of arable land (ca 1000 ha) and productive forestry land (2500 ha), but in the drainage area there are also restored and fairly newly constructed wetlands.</p><p>Today the Stockholm area receives its drinking water from Lake Mälaren, but if there would be any pollution of this source, Lake Bornsjön would act as the water source. The area surrounding the lake was bought already in 1899 by Stockholm Stad for protection of the lake and was taken over 1993 by Stockholm Vatten AB. It has been a water protection area from 1988 and it was also accepted as a nature reserve in 1995. This involve some restrictions like prohibition against fishing, bathing and to tread the ice on the lake in the winter and only back-up water activities are allowed on and in the lake. According to information from the 1970s the phosphorus content increased in the surface and bottom waters and later in the mid 1980s the phosphorus decreased (Lännergren 1996). 1986 Lake Bornsjön showed some indications of a deteriorated lake status which lead to an investigation the following year that showed an accumulation of phosphorus in the sediment of the deepest parts of the lake (Pettersson 1987).</p><p>The purpose of the study was to investigate the present leakage of phosphorus from the sediment to the water column in Lake Bornsjön today and to compare the results with the investigation carried out in 1987. The study aims is also to investigate in which basin the leakage of phosphorus is most severe and to try to explain the variation between the basins. Three different methods were used to analyse the content of the phosphorus in the sediment; phosphorus fractionation, ICP-AES and XRF. In a fractionation the phosphorus is determined in six different forms such as NH4Cl-P (loosly sorbed P, porewater-P and in hardwater lakes also CaCO3- associated P), BD-P (P absorbed to iron and manganese and these forms are sensitive for low redox potential), NaOH-rP (P associated mainly with aluminium), NaOH-nrP (organic-P including bacteria-incorporated P), HCl-P (assumed endured apatite) and finally residual phosphorus witch you calculate by taking total phosphorus (TP) minus the extracted forms of phosphorus. The residual phosphorus consist refractory organic P and inert inorganic P. The ICP-AES - method (Inductively Coupled Plasma Atomic Emission Spectroscopy), is used to investigate the amount of elements, in this study phosphorus, iron and aluminium. ICP-AES is a multi element technique and the method can be used to determine around 40 different elements. In the XRF - method (X-ray-fluorescence) the sample is irritated by X-ray beams which results in electron excitation and when the electron falls back in to their original shells it establish fluorescence radiation (Hulterström 2006). The radiation energy is registered by a half detector and dependence on from which shell that the electron falls from it create different kinds of energy and this makes it measurable. With a pulse counter the different energies and elements are separated. The XRF- technique is more sensitive in detecting heavier element.</p><p>Field work was carried out from a boat using a gravity corer to collect lake sediment cores. In total 18 sediment cores was sampled which were taken at three different occasions in the fall 2006. The sediment sampling was carried out at the same time as the ordinary water samples were collected. The study also included a phosphorus leakage experiment in vitro where sediment cores with the water column above were incubated in 22 days.</p><p>The results of the investigation show that there is highest share accumulated total phosphorus, deeper than 10 m, with an assumed sediment density of 1 000 000 g/m3 (personal communication Rydin Emil) in the Skårby Basin (BS) 14,90 g/m2 but the highest amount of mobile phosphorus was found in the Bornsjö Basin (BB) 7,08 g/m2 based on data from sediment layer 0-17 cm. The average of total phosphorus in the sediment for the whole lake deeper than 10 m was at the current sampling occasion (2006-10-17) 12,08 g/m2 and mobile phosphorus, 6,54 g/m2. These results are presumably an affect of the artificially induced oxygen in the bottom water by the hypolimnion unit. The hypolimnion unit is placed in the Bornsjö Basin (BB) on 14 m water deep and through aeration of the bottom water the phosphorus accumulates in the sediment. The oxygen that is brought down to the bottom of the lake forms an aerobic environment near the sediment surface which prevents phosphorus leakage (internal loading). Because of a high amount phosphorus in the sediment of Lake Bornsjön is bound to ferric iron (Fe3+ or Fe(III)) in aerobic condition, there is a big threat that this phosphorus will be released when Fe(III) will be reduced to Fe(II) and there is a large risk that it will react with SO42 under anaerobic conditions. The water depth and the location in the lake plays an important role of the amount accumulated phosphorus which is statistically shown in the study. The hypolimnion unit was initiated in 1987 and has since then been active every year between June - October except 2004. Under 2004 a pumping project took place in the Edeby Basin. During this project the bottom water was pumped out of the lake and the result in this rapport show some indications that this project was successful to reduce phosphorus content in Lake Bornsjön. The phosphorus amount in the water during 2006 May-October was 17,27 μg P/L and by this value the lake is a mesotrophic lake.</p><p>The results from the comparison between different methods to analyse phosphorus show that the methods give quite similar results but the fractionation method is the most informative method about how phosphorus is connected to other substances and consequently the most adequate method to use to calculate the mobile amount of phosphorus.</p><p>It can be concluded that the phosphorus in Lake Bornsjön mainly derive from the internal loading of the lake, but also from the diffuse inflow from the arable land surrounding the lake and from the densely populated parts in the drainage area. The hypolimnion unit that artificially induces oxygen in the bottom water and makes the phosphorus accumulate in the sediment is positive because phosphorus stays in the lake and is not transported to other lakes or the Baltic Sea.</p> / <p>Bornsjön ligger till största delen i Salems kommun, 3 mil sydväst om Stockholm. Sjön är en sprickdalssjö och består av tre bassänger utsträckta i nordväst-sydostlig riktning. Bornsjöns yta är 6,7 km2 med ett maxdjup på 18,3 m och ett medeldjup på 9,8 m och omsättningstiden för vattnet är 6,5 år. Nederbördsområdets area är 42 km2 och består till stor del av jordbruksmark (ca 1000 ha) och produktiv skogsbruksmark (2500 ha) och inom området finns även återställda och nyanlagda våtmarker.</p><p>Bornsjön är Stockholms viktigaste reservvattentäkt. Sjön och området runtomkring köptes upp för att skyddas redan 1899 av Stockholms stad, övertogs 1993 av Stockholm Vatten AB. Området kring sjön är sedan 1988 ett vattenskyddsområde, dessa bestämmelser reviderades år 2006 och dessutom godkändes det som naturreservat år 1995. Detta innebär vissa restriktioner såsom förbud att bada, fiska, beträda sjön vintertid och endast vattenvårdsverksamhet får förekomma i och på sjön. Uppgifter från 1970-talet visade att fosforhalterna i yt- och bottenvattnet ökade för att sedan minska i mitten på 1980-talet (Lännergren 1996). 1986 visade Bornsjön indikationer på försämrad sjöstatus vilket ledde till en undersökning år 1987 vilket visade en ackumulation av fosfor i sedimentet i sjöns djuphålor (Pettersson 1987).</p><p>Syftet med denna studie är att utreda den fosforfrigörelse som sker från sedimenten i Bornsjön idag samt att jämföra resultaten med den undersökning som genomfördes 1987. Utredningen har för avsikt att kartlägga var i Bornsjöns tre olika bassänger det läcker mest fosfor från sedimentet till bottenvattnet och förklara varför frigörelsen eventuellt varierar i sjöns olika delar. I studien används tre olika typer av metoder för att fastställa fosformängden, vilket gör att en jämförelse mellan dessa metoder är möjlig. Sammanlagt provtogs 18 sedimentkärnor vid tre olika tillfällen. Sedimentprovtagningen gjordes i anslutning till ordinarie vattenprovtagningar vilket innebär att vattenanalysernas resultat var tillgängliga. Även ett fosforfrigörelseförsök gjordes in vitro där sedimentkärnor med ovanstående vattenpelare inkuberades i 22 dagar.</p><p>Resultatet av studiens olika delar visar att det finns mest ackumulerad totalfosfor, under 10 meters vattendjup, med en antagen sedimentdensitet på 1 000 000 g/m3 (muntlig kommunikation Rydin Emil) i Skårbybassängen (BS), 14,90 g/m2, men att det finns mest mobil fosfor i Bornsjöbassängen (BB), 7,08 g/m2 baserat på data från sedimentlagret 0-17 cm. Genomsnittlig totalfosforhalt i sedimentet för hela sjön under 10 meters vattendjup, var vid provtagningstillfället 12,08 g/m2 samt mobil fosforhalt på 6,54 g/m2. Vad som påverkat detta resultat mest är förmodligen det artificiellt tillförda syret i bottenvattnet som skapats med hjälp av en hypolimnionluftare placerad i Bornsjöbassängen. Genom att syresätta bottenvattnet ackumuleras fosfor i sedimentet. Även vattendjupet och provplatsen i sjön spelar en viktig roll i sammanhanget vilket bevisas statistiskt i studien. Fosformängden i vattenmassan under år 2006 maj-oktober var 17,27 μg P/L. Vad gäller metodjämförelsen kan konstateras att resultaten följer varandra relativt väl men att fosforfraktionering är den mest informativa metoden då det gäller utredning av fosfor i förhållande till andra ämnen, såsom t.ex. järn, aluminium, kalcium och organiska ämnen.</p><p>Som slutsats kan konstateras att fosforn i Bornsjön härrör mestadels från internbelastningen i sjön och de diffusa utsläppen som sker då tillflödena till sjön rinner genom näringsrik jordbruksmark men även från de mer tätbebyggda delarna av området.</p>

<p>This paper aims to give an understanding on the aspects that influences the choice of cropsand agricultural methods in Babati, Tanzania. Drought is a reoccurring problem in this part ofTanzania, which affects a majority of the towns’ farmers. This fact is likely to affect thechoice of crop as well as the limitations when it comes to the choices in cultivation. But thechoice itself has implications on its surrounding and can be affected by the surrounding. Tounderstand the circumstances, a wider picture will be depicted and an evaluation of thegeography of Babati and on its climate conditions. The results from this study suggest thatlack of crop rotation pose as a problem that should be studied. Furthermore, green manurefrom legumes and plants like Tithonia could be a less expensive alternative but can stillfunction as an effective fertilizer. Concerning the drought issue the study can not concludethat drought resistant crops would have any big improving effects. Nevertheless there is someevidence advocating that it could be apart of the solution in terms of avoiding some of thenegative effects brought on by drought.</p>

<p>The Baltic Sea is an evolutionary young sea that have developed a low salinity in its water from the fresh water that flows from the north and saltwater that flows from the south of the sea. The low salinity is too low for many marine organisms and too high for many freshwater organisms. Species like the blue mussel, which have adapted to the low salinity, may have developed different protein expression as a result. To study which protein that have been expressed in the organism proteome analysis is often used. 2-dimensional electrophoresis may be the only method that can do this kind of analysis.</p>

<p>The freshwater pearl mussel Margaritifera margaritifera is an endangered species. To survive, the young mussels demand a fairly coarse bottom material containing an appropriate quantity of organic substrate to survive without suffocating. In order to estimate if a bottom is suitable for juvenile mussels, samples of the sediment are needed. To obtain samples a sampling device called the Mulv collector has been developed within this project. Bottom samples were collected from 18 stations in 4 south Swedish streams, Vramsån, Kling-storpsbäcken, Brönnestadsån and Bräkneån. No rejuvenation of the mussel was found at the stations containing more than 25% fine material.</p>

<p>Människan har brukat jorden sen många tusen år tillbaka. Förmågan att förändra</p><p>odlingslandskapet och påverka dess utseende och innehåll har dock varit störst efter andra</p><p>världskriget. Många av jordbrukslandskapets arter är synantroper dvs. att de direkt eller</p><p>indirekt är beroende av människan för sin existens. Dessa arter har varit människans</p><p>följeslagare i tusentals år. Åkerogräsen har kunnat öka och finna goda tillväxtchanser i</p><p>dåtidens odlingslandskap men efter andra världskriget ökade mekaniseringen och</p><p>användandet av herbicider och konstgödning i det traditionella jordbruket, vilket snabbt</p><p>förändrade förutsättningarna för åkerogräsen. Åkerogräsen är idag i stor utsträckning hotade</p><p>på grund av dagens rationella jordbruk. Olika arter är hotade på grund av olika faktorer vilket</p><p>kunnat härledas i forskning kring de hotade åkerogräsen.</p><p>Medvetenheten om det ökade hotet mot den biologiska mångfalden har ökat och intresset för</p><p>vårt biologiska arv bland allmänheten blir allt större. Dessutom har politiska beslut påverkat i</p><p>rätt riktning och slagit vakt om den biologiska mångfalden. Idag har olika bevarandeformer</p><p>för åkerogräsen skapats bl.a. Projekt Allmogeåker. Det är ett projekt som syftar till att bevara</p><p>och förbättra ogräsarternas förutsättningar. Andra alternativ för bevarande är blomsteråkrar,</p><p>rätt skötsel av värdefulla vägkanter och viltåkrar. I det moderna jordbruket kan åkerogräsen</p><p>bevaras med hjälp av jordbrukspolitiken i form av miljöstöd och specialstöd. Problematiken</p><p>kring åkerogräsens situation är idag aktualiserat i och med att ett nytt Åtgärdsprogram för</p><p>bevarande av Rödlistade Åkerogräs håller på att utarbetas.</p><p>Vårt syfte med rapporten är att praktiskt tillämpa de rekommendationer2 som Roger Svensson,</p><p>Marita Wigren-Svensson och Torleif Ingelög har satt upp i boken ”Hotade åkerogräs, biologi</p><p>och bevarande i Allmogeåkrar” och sedan utvärdera denna allmogeåker med två olika</p><p>spannmålsgrödor och olika rödlistade åkerogräs. Utifrån detta har vi arbetat med följande</p><p>frågeställningar:</p><p>• Hur ser situationen ut för de hotade åkerogräsen?</p><p>• Vad är anledningarna till dessa förhållanden?</p><p>• Vad är orsaken till skillnaderna i grobarhet hos de olika åkerogräsen?</p><p>• Vad beror skillnaderna i grobarhet på vad gäller korn kontra råg</p><p>• Är allmogeåkrar en framtida bevarandeform för de hotade åkerogräsen?</p><p>• Finns det andra alternativ för att bevara åkerogräsen?</p><p>Uppsatsen bygger på dokumentation av vår anlagda allmogeåker i Övarp, i nordvästra Skåne.</p><p>Dokumentationen har pågått från april 2004 till maj 2005. Vi har studerat olika faktorer som</p><p>kan ha påverkat resultaten och diskussionen bygger på våra resultat och erfarenheter utifrån</p><p>dessa. Några faktorer är väder, viltskador, markförhållande, olika egenskaper hos grödorna</p><p>och åkerogräsen. Vår sammanställning har gett resultat som kan tolkas utifrån specifika</p><p>faktorer snarare än allmängiltiga teorier. Resultatens svårighet är dess jämförbarhet.</p><p>Problemet är dels att det saknas liknade studier och dels att varje allmogeåker är unik genom</p><p>sina olika förutsättningar och egenskaper. Därför vore vidare studier på allmogeåkern i Övarp</p><p>en önskvärd uppföljning för att producera ett jämförbart material. Resultaten visar på hur de</p><p>specifika arternas unika egenskaper slår igenom trots en anpassad miljö som gynnar tillväxten</p><p>av åkerogräs. Vår resultatdiskussion kan därmed ses som en vägledning i att anlägga</p><p>allmogeåkrar eller liknande miljöer.</p>

<p>Klimatförändringar i världen är ett stort problem där alla måste hjälpa till för att stävja dess inverkan på vår livsföring. Ett problem är utsläppen av växthusgaser där djurhållningen står för en viss del. Vid djurhållning sker det en avgång av metangas både genom matsmältning och genom gödselproduktion där endast den sistnämnda är påverkbar till en rimlig kostnad. För att beräkna avgången av metan från djurhållningen i Helsingborgs stad måste man göra en inventering av djurantalet. Ett bra sätt för att utvinna metangas ur gödseln är att röta den och sedan förbränna den till koldioxid och vatten. Även koldioxid är en växthusgas men metan bidrar 21 gånger mer till växthuseffekten än koldioxid. Det som blir kvar efter rötningen är en god växtnäring med ett större växtvärde än stallgödsel. Om en lantbrukare investerar i en biogasanläggning kan detta innebära stora energivinster respektive miljövinster. Det som är viktigt att tänka på är anläggningens storlek i förhållande till energianvändningen på lantbruket. Investeringskostnaden är stor men vinsten blir positiv för en stor djurproducent.</p><p>Miljövinsterna är många, minskning av växthusgaser och mindre övergödning vilket även är bra för ekonomin.</p>