Society depends on bumblebees for the ecosystem service in the pollination of crops. Bumblebee declines have been documented, mostly due to intensification of agriculture and loss of species-rich semi-natural grasslands, an important bumblebee habitat. To conserve bumblebee diversity and the ecosystem service of pollination, it is important to do analyses on multiple spatial scales to see how the intensification of agriculture affects bumblebees at a landscape level. In this study, I related abundance of bumblebees in 476 sites in southern Sweden (total abundance and abundance of declining/non-declining, long-tongued/short-tongued, and species preferring open terrain vs. forest boundaries) to amount of land use types (semi-natural grassland, arable land, forest, water and “other land use”) at 34 spatial scales (radii 100 to 40,000 m). Arable land had a negative effect on total bumblebee abundance at scales from 464 to 10,000 m and forest had a negative effect at scales from 2929 to 5412 m. Semi-natural grassland showed no clear effects – however, the partial regression coefficients were consistently negative. Arable land had a negative effect on non-declining species, long- and short-tongued species and on species preferring forest boundaries at larger scales, e.g. regions dominated by agriculture. Forest had a positive effect at smaller scales on species preferring forest boundaries and a negative effect at larger scales on species preferring open terrain and on declining species. The results suggest that arable land is a non-habitat for bumblebees and that semi-natural grassland does not affect bumblebee abundance at a landscape level.

The research contained in these papers embodies both results from direct archaeological investigation and also the development of techniques (geophysical, chronological and geoarchaeological) in order to understand long-term settlements and their associated landscapes in Orkney and Shetland. Central to this research has been the study of soil management strategies of arable plots surrounding settlements from the Neolithic to the Iron Age. It is argued that this arable system provides higher yields in marginal locations. The ability to enhance yield in good years and to store surplus can mitigate against shortage. Control and storage of this surplus is seen as one catalyst for the economic power of elite groups over their underlying or ¿client¿ population. The emergence of a social elite in the Iron Age, building brochs and other substantial roundhouses of near broch proportions, is seen as being linked to the control of resources. Evidence at the site of Old Scatness indicated that there was a continuity of wealth and power from the Middle Iron Age through the Pictish period, before the appearance of the Vikings produced a break in the archaeological record. The Viking period saw a break in building traditions, the introduction of new artefacts and changes in farming and fishing strategies. Each of the papers represents a contribution that builds on these themes.

Tyrimo tikslas – nustatyti armens apvertimo kokybės įtaką vasarinių miežių (Hordeum vulgare L.) pasėlio piktžolėtumui modeliniame lauko tyrime. Modelinis lauko tyrimas vykdytas LŽŪU bandymų stotyje 2009-2010. Tirti keturi armens apvertimo variantai: armuo apverstas 135° (kontrolinis variantas), 157,5º ir 180° kampu bei neverčiamas (0°). Įrengti stacionarūs 0,25 m2 modeliniai laukeliai Nustatyta piktžolių vasarinių miežių derliuje, rūšinė sudėtis, biomasė ir skaičius, miežių antžeminės dalies biomasė ir stiebų skaičius, derlius, 1000 grūdų masė ir kiti parametrai. Pasėlio piktžolėtumo ir piktžolių sėklų pasiskirstymo armenyje duomenys vertinami dispersinės analizės metodu, nustatant esminio skirtumo ribą (R05, R01) ir vidurkių vidutinę kvadratinę paklaidą Apibendrinus tyrimo duomenis, gauti rezultatai parodė, kad esant skirtingam armens apvertimo kampui piktžolių biomasė pasėlyje skyrėsi iki 3 kartų. Piktžolių sėklų atsargose dirvoje vyravo trumpaamžės piktžolės, daugiausiai baltoji balanda (Chenopodium album L.). Paviršiniame dirvos sluoksnyje piktžolių sėklų pasiskirstymas tarp variantų buvo nevienodas (skyrėsi kelis kartus) skirtingais metais. Eksperimento rezultatai iš esmės patvirtino hipotezę, kad nuo armens apvertimo kampo priklauso pasėlio piktžolėtumas, tačiau reikėtų atlikti papildomus tyrimus ir nustatyti optimalų armens apvertimo kampą mūsų klimato ir dirvožemių sąlygomis. / The aim of the investigation was to estimate the influence of arable soil turnover angle on spring barley (Hordeum vulgare L.) crop yield and weediness in model field experiment. The model field experiment carried out at the Experimental Station of LŽŪU in 2009-2010. Four arable soil turnover angle treatments were investigated: 135° (control treatment), 157.5° and 180° and not overturned (0°). Stationary 0.25 m-2 model fields were equipped. The following parameters were measured: weeds harvested along with barley (weed species composition, weed biomass and number), spring barley density, and stem density, yield, 1000 grain weight and other parameters. Weediness and weed seed distribution in the arable soil layer were assessed by variance method by determining the LSD05, LSD01 and the average SEM Summarized survey data revealed that weed biomass in the spring barley crop differed by three times at the different arable soil turnover angle, short-living weeds dominated in the seed bank, mostly Chenopodium album L., weed seed distribution in top soil layer as well as spring barley yield has been uneven between the treatments (several times) in different years. Experimental results broadly confirmed the hypothesis that the arable soil overturning angle has influence on the crop yield and weediness, but further studies should be carried out to determine the optimum turnover angle for our climate and soil conditions.

The research contained in these papers embodies both results from direct archaeological investigation and also the development of techniques (geophysical, chronological and geoarchaeological) in order to understand long-term settlements and their associated landscapes in Orkney and Shetland. Central to this research has been the study of soil management strategies of arable plots surrounding settlements from the Neolithic to the Iron Age. It is argued that this arable system provides higher yields in marginal locations. The ability to enhance yield in good years and to store surplus can mitigate against shortage. Control and storage of this surplus is seen as one catalyst for the economic power of elite groups over their underlying or 'client' population. The emergence of a social elite in the Iron Age, building brochs and other substantial roundhouses of near broch proportions, is seen as being linked to the control of resources. Evidence at the site of Old Scatness indicated that there was a continuity of wealth and power from the Middle Iron Age through the Pictish period, before the appearance of the Vikings produced a break in the archaeological record. The Viking period saw a break in building traditions, the introduction of new artefacts and changes in farming and fishing strategies. Each of the papers represents a contribution that builds on these themes.

STUDENT NUMBER: 0516082G Master of Science in Resource Conservation Biology Faculty of Science / The aim was to determine the availability of marula (Sclerocarya birrea) (A.Rich.) Hochst. Subsp.cafra (Sond.) Kokwaro trees for the harvesting of nut oils, through determining abundance, population structure and regeneration capacity, within the context of the socioeconomic and biophysical dimensions of villages in Zvishavane, Zimbabwe. Both arable and non arable lands in the study area were sampled within four randomly selected villages to measure species abundance, regeneration and population dynamics of the trees. The socioeconomic factors influencing marula commercialisation were determined through participatory rural appraisal (PRA) and household questionnaire survey techniques. Vegetation characteristics were assessed through the point centre quarter (PCQ) method by placement of transects across sampled villages. All households (100%) collected marula fruit for their household use, mainly for brewing marula beer, making jam and selling kernels for snacks or oil pressing. In 2005, the mass of marula harvest per household averaged 160 ± 18 (SD) kg, with a range of 50-800 kg within the study area. A linear regression analysis indicates no increase in mass of marula harvest with larger sizes of household (r2 = 0.0089, d.f = 50, p = 0.4048). In addition, household interviews revealed that there was no association between level of household wealth status and the household’s use of traditional medicine from marula trees (χ2 = 0.2233, d.f = 2, p = 0.8944). The vegetation survey indicated a elatively high density of marula within the study area of 8.03 ± 3.19 stems ha-1. There was a significant difference in marula densities between arable and non arable land uses (F1, 197 = 11.92, p=0.001). The arable land had 6.40 ± 5.29 stems ha-1 while non arable land had three times more at 19.63 ± 11.82 stems ha-1. However there was no significant difference in densities between the villages in the study area (F 3, 195 =1.063, p= 0.366). There was a significant difference between marula tree diameters between arable and non arable land (t 92, 107 = 1.69, p = 0.0401). The arable land had generally bigger tree diameters (31.2 ± 25.3 cm) than non arable land (26.5 ± 20.8 cm), suggesting a form of domestication through allowing marula to grow around homesteads and crop fields. The investigation of marula size class profiles shows a large proportion of smaller diameter trees and this indicates ongoing recruitment of trees into the population. A closer analysis of the smallest diameter class shows a higher proportion of saplings (> 6cm diameter) than of seedlings (< 4cm diameter). Fruit harvesting seems to have a low potential for any negative impact, compared to other uses of marula trees. However fruits have the highest economic return and therefore should be targeted for the commercialisation activities. The management of some destructive forms of marula tree use (such as harvesting for bark, firewood, and carving wood) however, do need to be monitored to limit negative impacts on the population. There is also a need to determine the annual quantity of harvestable marula fruits and also the sex ratio of marula trees (a dioecious species) on this particular site, as a prelude to developing sustainable harvesting quotas, so that harvesting rates do not exceed the capacity of populations to replace the individuals extracted. There are some non governmental organisations (NGOs) and local institutions that are working towards natural resources conservation in the area. Zvishavane water project (ZWP) and Phytotrade Africa are assisting the rural producers in marula commercialisation activities through providing information on processing, packaging and marketing. At a current value of US$1 kg-1of fruit, the 3200 ha study area is estimated to yield a total harvest of 1 120 000 kg of marula fruit per year, and this should translate to an approximate total value of $1 120 000 per year for the whole area. There is still a need to expand the supply of processed goods with added value to wider markets locally, nationally, and internationally. There is therefore an indication that marula products offer a promising economic alternative for the people in the rural areas of Zvishavane area and southern Africa as a whole. The cash injection earned from selling fresh marula products comes at a particularly crucial time of the year, when money is required for school fees, uniforms and books. However there is a need for long-term monitoring and evaluation of socio-economic and environmental impacts of marula commercialisation so as to achieve sustainable resource utilisation in the region.

L’intensification des processus écologiques proposée par l’agroécologie est très dépendante du contexte agricole. Un renouvellement des savoirs sur l’exploitation agricole est nécessaire pour adapter chaque pratique agroécologique. Dans cette thèse, nous avons étudié l'activité d'expérimentation des agriculteurs, définie comme un processus de mise à l’épreuve de pratiques embarquant des hypothèses tant sur leur mise en œuvre que sur les processus agroécologiques que ces pratiques visent à induire. Notre travail est basé sur des enquêtes auprès de 17 agriculteurs majoritairement drômois, étant soit en maraîchage diversifié, soit en grandes cultures.Nous avons formalisé l'activité d'expérimentation des agriculteurs avec deux notions : la situation expérimentale (SE) et l'itinéraire d'expérimentation (ITE). Elles concernent respectivement le temps court (annuel ou infra-annuel) et le temps long (pluri-annuel) et font l'objet des deux premiers chapitres de résultat. Dans le premier, nous avons construit un cadre d’analyse des SEs comprenant des phases de conception, de réalisation et d’évaluation. A partir de ce cadre, nous avons étudié la diversité d’un échantillon de 181 SEs et identifié 10 groupes de SEs organisés en 4 clusters. La typologie obtenue dépend d'une variable particulière qui est le type de lien aux SEs précédentes. Dans le deuxième chapitre de résultat, nous avons approfondi ces liens en nous intéressant aux ITEs, définis comme la combinaison de différentes SEs portant sur une thématique agroécologique particulière. Nous avons identifié 4 types d'ITE qui diffèrent par leur intensité expérimentale, les liens entre SEs et l'émission ou non de nouvelles branches expérimentales.Le troisième chapitre de résultat traite la question du développement des connaissances des agriculteurs grâce à leurs expérimentations. Après avoir caractérisé différentes formes de connaissances, plus ou moins stabilisées, nous proposons trois processus de développement de connaissances avancées grâce aux expérimentations menées.Le modèle SE/ITE est prometteur pour accompagner les agriculteurs. La frise chronologique des SEs organisées en ITE représente un outil de réflexivité potentiel. / The intensification of ecological processes proposed by agroecology is highly dependent on the agricultural context. A renewal of farming knowledge is necessary to adapt each agro-ecological practice. In this thesis, we studied farmers’ experiments, defined as a process of testing practices that embody hypotheses both on their implementation and on the targeted agro-ecological processes. Our work is based on surveys of 17 farmers, mainly Drôme farmers, who were either diversified market gardeners or cereal farmers.We have formalized the farmers’ experiments with two notions: the experimental situation (SE) and the experimentation itinerary (ITE). They concern respectively short time (annual or infra-annual) and long time (multi-year) and are the subject of the first two chapters of the results. In the first one, we built an analytical framework that includes design, implementation and evaluation phases. From this framework, we studied the diversity of a sample of 181 SEs and identified 10 groups of SEs organized into 4 clusters. The typology obtained depends on a particular variable which is the type of link to previous SEs. In the second chapter of the result, we have deepened these links by focusing on ITEs, defined as the combination of different SEs on a particular agro-ecological theme. We identified 4 types of ITEs that differ in their experimental intensity, the links between SEs and the emission or not of new experimental branches.The third chapter of the result deals with the question of farmers developing knowledge through their experiments. After having characterized different forms of knowledge, more or less stabilized, we propose three processes for the development of advanced knowledge through experimentation.The SE/ITE model is promising to support farmers. The chronological timeline of SEs organized in ITEs represents a potential reflexivity tool.

1. Seed bank and seed rain represent dispersal in time and space. They can be important sources of diversity in the rural landscape, where fragmented habitats are linked by their histories. 2. Seed bank, seed rain and above-ground vegetation were sampled in four habitat types (abandoned semi-natural grassland (ABA), grazed former arable field (FAF), mid-field islet (MFI) and grazed semi-natural grassland (SNG)) in a rural landscape in southern Sweden, to examine whether community patterns can be distinguished at large spatial scales and whether seed bank and seed rain are best explained by current, past or intended future vegetation communities. 3. We counted 54 357 seedlings of 188 species from 1190 seed bank and 797 seed rain samples. Seed bank, seed rain and above-ground vegetation communities differed according to habitat. Several species characteristic of managed grassland vegetation were present in the seed bank, seed rain and vegetation of the other habitats. 4. The seed banks of SNGs and the seed rain of the FAFs were generally better predicted by the surrounding above-ground vegetation than were the other habitat types. The seed rain of the grazed communities was most similar to the vegetation in the FAFs, while the seed banks of the abandoned grasslands most resembled the vegetation in SNGs. 5. Gap availability and seed input could be limiting the colonisation of target species in FAFs, while remnant populations in the seed bank and the presence of grassland specialists in the above-ground vegetation indicate that abandoned grasslands and mid-field islets could be valuable sources of future diversity in the landscape after restoration. 6. Synthesis and applications. SNG communities are able to form seed banks which survive land-use change, but their seed rain does not reflect their above-ground communities. It is important that grassland plants set seed. By connecting existing grasslands with restoration targets, increased disturbance in the target habitats would allow for colonisation via the seed bank or seed rain, while decreased grazing intensity would benefit seed production in the source grasslands. Otherwise, landscape-wide propagule availability might increase with a more varied timing and intensity of management.

Understanding pesticide transport is crucial to evaluate their ecological impact on ecosystems. Current knowledge on the spatial variability of pesticide deposition, the impact of erosion on pesticides export and the in situ pesticide degradation is very limited at the catchment scale. In this thesis, characterisation and modeling at two scales, the plot and catchment, were combined in two agricultural contexts. A formalism was developed to predict pesticide transport in runoff and was integrated in LISEM (LImbourg Soil Erosion Model). The results show that impermeable roads contributed to more than 40% to the overall load of fungicides exported via runoff from the vineyard. Pesticide partitioning between suspended solids and runoff water differed largely according to the molecules and the hydrological dynamics. The occurrence of degradation products and the enrichment of one enantiomer were observed suggesting the potential of chiral analyses for assessing biodegradation of chiral pesticides at such scale. Overall, the investigation demonstrated that combining different approaches enable a better understanding of pesticide transport.

Diss. Uppsala : Sveriges lantbruksuniv., 2003.

Comprendre le transport des pesticides est crucial pour évaluer leur impact écologique. Les connaissances sur la variabilité spatiale des dépôts de pesticides, l'impact de l'érosion sur leur export et leur dégradation in situ restent très limitées à l'échelle des bassins versants. La caractérisation expérimentale et la modélisation ont donc été combinées à deux échelles, parcelle et bassin versant, dans deux contextes agricoles. Un formalisme a été développé pour prédire le transport des pesticides par ruissellement et a été intégré dans le modèle LISEM (LImbourg Soil Erosion Model). Les résultats montrent que les surfaces imperméables contribuent significativement à la masse exportée par ruissellement du vignoble. La partition des pesticides entre phase dissoute et particulaire diffère considérablement selon les molécules et le forçage hydrologique, et la présence de produits de dégradation et un enrichissement en R-métolachlore ont été observés ce qui souligne le potentiel des analyses énantiomériques pour évaluer la biodégradation des pesticides. Globalement, cette étude a démontré que la combinaison des échelles et des approches permet une meilleure compréhension du transport des pesticides. / Understanding pesticide transport is crucial to evaluate their ecological impact on ecosystems. Current knowledge on the spatial variability of pesticide deposition, the impact of erosion on pesticides export and the in situ pesticide degradation is very limited at the catchment scale. In this thesis, characterisation and modeling at two scales, the plot and catchment, were combined in two agricultural contexts. A formalism was developed to predict pesticide transport in runoff and was integrated in LISEM (LImbourg Soil Erosion Model). The results show that impermeable roads contributed to more than 40% to the overall load of fungicides exported via runoff from the vineyard. Pesticide partitioning between suspended solids and runoff water differed largely according to the molecules and the hydrological dynamics. The occurrence of degradation products and the enrichment of one enantiomer were observed suggesting the potential of chiral analyses for assessing biodegradation of chiral pesticides at such scale. Overall, the investigation demonstrated that combining different approaches enable a better understanding of pesticide transport.