Les cours d’eau de tête de bassin versant, malgré leurs tailles réduites, jouent des rôles importants pour le fonctionnement des milieux situés en aval, et rendent de nombreux services écologiques. Depuis l’émergence du River Continuum Concept, le fonctionnement de ces cours d’eau est considéré comme reposant principalement sur les apports allochtones de matière organique détritique par opposition aux écosystèmes aval de plus grande taille dans lesquels la production primaire autochtone est considérée comme prépondérante. Bien que les détritus soient, par définition, des ressources de moindre qualité pour leurs consommateurs que les végétaux vivants, le rôle des facteurs qui limitent la production biologique et les processus fonctionnels dans ces écosystèmes détritiques reste encore peu exploré. Par exemple la carence en éléments minéraux essentiels (notamment en azote et en phosphore) dans les détritus peut limiter le développement des organismes vivants dans les cours d’eau. De ce fait, la disponibilité en éléments minéraux dans la colonne d’eau, en stimulant la croissance, l’activité des décomposeurs et la qualité élémentaire des ressources par le processus d’immobilisation microbienne, pourrait contrôler pour partie les processus écologiques en jeu dans ces écosystèmes. En étudiant in situ la réponse des communautés microbiennes aux nutriments le long d’un gradient d’occupation des sols, nos travaux ont mis en évidence un effet positif des éléments dissous (N et P) sur la décomposition des litières et les activités enzymatiques des décomposeurs, et ce même pour les niveaux en nutriments les plus élevés du gradient, pour lesquels des effets inverses étaient attendus. Indépendamment, dans des cours d’eau anciennement soumis à de forts dépôts acidifiants, nous avons pu observer une récupération du processus de décomposition des litières. Néanmoins, cette restauration s’accompagnant d’un appauvrissement marqué en N, des perturbations du fonctionnement de ces cours d’eau pourrait se manifester à terme. Le rôle de la production primaire dans les cours d’eau de tête de bassin versant a ensuite été questionné. En effet, bien qu’étant mineur quantitativement, l’apport de carbone de forte qualité pourrait jouer un rôle non négligeable sur le fonctionnement des cours d’eau de tête de bassin versant. En particulier, l’importance et le rôle des apports en acides gras polyinsaturés (AGPI) via les biofilms phototrophes ont été questionnés. En se basant sur un suivi de terrain sur 15 cours d’eau des Vosges le long d’un gradient d’acidification, nos recherches ont tout d’abord pu mettre en évidence la présence de biofilms diatomiques riches en AGPI, malgré le caractère très forestier de ces cours d’eau. Dans un second temps, une expérience en conditions contrôlées a permis d’observer le rôle positif des apports, mêmes faibles, de ressources diatomiques sur la croissance et la survie du crustacé amphipode Gammarus fossarum. Sans cet apport, ces organismes se sont avérés incapables de maintenir leurs niveaux internes d’AGPI, suggérant qu’une consommation de producteurs primaires autochtones était indispensable à ces organismes détritivores. Nos résultats ont ainsi pu mettre en évidence les rôles fondamentaux que peuvent jouer la disponibilité en éléments dissous (N et P) et la qualité du carbone dans les ressources sur la production biologique et sur le processus de décomposition des litières dans les cours d’eau de tête de bassin versant. Ces résultats appellent désormais à investiguer plus profondément les interactions entre ces deux facteurs limitants, et à comprendre dans quels contextes l’un des facteurs pourrait suppléer l’autre. En particulier, il sera intéressant de rechercher comment diverses perturbations anthropiques (xénobiotiques, réchauffement climatique etc…) pourraient affecter l’intensité ou la nature de ces limitations / Despite their reduced sizes, headwater streams play important roles in the functioning of downstream ecosystems and provide numerous ecological services. Since the River Continuum Concept, the functioning of these streams has been considered as mainly relying on allochthonous supplies of detrital organic matter for their functioning, in contrast with downstream ecosystems of larger size where primary production is considered to be predominant. Despite that detritus represent, by definition, a resource of lower quality for its consumers than living plants, the nature of the factors limiting the biological production and functional processes in these detrital ecosystems remains sparsely explored. First, the lack of essential elements (in particular nitrogen and phosphorus) in detritus could be a major constraint for the development of living organisms in streams. As a result, the availability of mineral elements in the water column, by stimulating the growth and activity of decomposers, but also by increasing the elemental quality of resources through microbial immobilization, could control ecological processes in a higher extent than previously believed in these ecosystems. By studying in situ, the response of microorganisms to nutrients availability along a land-use gradient, our results have shown a positive effect of the dissolved elements (N and P) on the decomposition of leaf litters and the enzymatic activities of the decomposers, even for the highest nutrient levels of the gradient, for which adverse effects were expected. Independently, in streams formerly subjected to acidification, we observed a recovery of the process of leaf litter decomposition. Nevertheless, this recovery was accompanied by a marked N reduction in the ecosystem, huge changes in stream functioning might be expected in the medium to long term. The role of autochthonous primary production was then questioned. Indeed, while being quantitatively minor, this contribution of high quality carbon may play a significant role in the functioning of headwater streams. In particular, the importance and role of polyunsaturated fatty acid (PUFA) intakes via phototrophic biofilms was questioned. Based on a field survey of 15 rivers in the Vosges Mountains along an acidification gradient, our results first showed the presence of diatomic biofilms rich in PUFA, despite these streams are clearly in a forested context. In a second step, an experimentation carried out under controlled conditions permitted to observe the positive role of diatomic resources, even in low concentrations, on the growth and survival of the crustacean amphipod Gammarus fossarum. Without this input, these organisms were unable to maintain their internal levels of PUFAs, suggesting that the consumption of autochthonous primary producers might be essential for these detritivore organisms. All our results permit to highlight the fundamental roles that can be played by the availability of dissolved elements (N and P) and the carbon quality of the resources on the biological production and on leaf litter decomposition in headwater streams. These results stress the need for more profound investigation of the interactions between these two limiting factors, and for understanding in which contexts one factor could supplement the other. In particular, it will be interesting to investigate to what extent various anthropogenic disturbances (xenobiotics, global warming, etc...) could affect the intensity or the nature of these limitations

This study was conducted in two shires of Laidley and Gatton in the Lockyer Valley in 1986. The research method used was a self-administered mail questionnaire sent to four hundred primary producers. The response rate received was 49.5 percent which is quite reasonable for a random sample of a non-specific interest group. The study area was divided into six zones based on the 198 respondents’ assessment of the enterprise from which they derived major income. The main approach of this project was a situational analysis o the Lockyer Valley. Central to this research was identification of the pressure and extent of problems relating to several aspects of land use, notably soil erosion, weed infestation; availability and quality of water and more general community-based problems. The characteristics of farm households, the role of family members in decision-making and tasks related to farm as well as home, were also included in this study. The Lockyer Valley is a major production area of vegetables as well as a mixed farming area. Natural pasture, which was extensively found in Zone 6, was largely used for cattle grazing. Generally, rural women were better educated than their husbands, and the ratio of educational level of husband and wife was higher than previous research findings. A large number of producers and their wives have taken off-farm work, and women tended to spend more time in off-farm employment. Only 6.1 percent of producers’ children had completed tertiary education and the majority of all sons were working on the farm. Partnership was found to be the major type of property ownership and inter-generational transfer of the property was the future plan. The producers who were from a non-farm upbringing and who had already taken up off-farm work intended to leave their properties at some time in the future. With the running of the farm business , 35 percent of rural women worked full-time in partnership with their husbands, and 42 percent worked part-time. However, 23 percent of rural women were homemakers and were not involved in running the farm business. The association between decision-making of husband and wife and situational factors such as ownership, involvement in farm tasks, record-keeping, education, on-farm upbringing and age were analysed. Joint involvement of wives in decision-making was to be related to ownership, farm tasks and record-keeping. However, husbands were more likely to take a major role in decision-making if they were more educated and had an on-farm upbringing. Age was found to be a factor affecting joint decision-making, although this result conflicted with findings of earlier research. The opinions of the farm community in identifying the problems of the specific small area in the Lockyer Valley were revealed. Lantana was the most severe weed problem in the whole catchment. The catchment area also had problems with wattle. The recommended control method of lantana was replacement by improved pasture, but it was adopted by few primary producers. Soil erosion in the form of gullies, bank erosion, sheet erosion, salinity and flooding were some of the problems perceived by the local community. Regular ‘slash and burn’ was practised by most of the producers. This is one of the causes of land degradation. Bore, creek and river, and dam were the main water sources for farm supply and irrigation. Only 60 percent of bored had adequate water supply and good water quality. Farm dam and creek/river sources were less reliable due to the inadequate availability of water. Consequently, operators at about half the cropped farms had to stop growing some vegetables which were previously commercially successful. Within the context of farm family needs, emphasis was placed on conservation of water, because of the erosion and water problems. The community’s opinion on community development activities emphasised the involvement of farm families. Finally, suggestions for the extension program which should be emphasised on rural development by means of community participation were included. The bases for further studies was also provided in this report.

This study was conducted in two shires of Laidley and Gatton in the Lockyer Valley in 1986. The research method used was a self-administered mail questionnaire sent to four hundred primary producers. The response rate received was 49.5 percent which is quite reasonable for a random sample of a non-specific interest group. The study area was divided into six zones based on the 198 respondents’ assessment of the enterprise from which they derived major income. The main approach of this project was a situational analysis o the Lockyer Valley. Central to this research was identification of the pressure and extent of problems relating to several aspects of land use, notably soil erosion, weed infestation; availability and quality of water and more general community-based problems. The characteristics of farm households, the role of family members in decision-making and tasks related to farm as well as home, were also included in this study. The Lockyer Valley is a major production area of vegetables as well as a mixed farming area. Natural pasture, which was extensively found in Zone 6, was largely used for cattle grazing. Generally, rural women were better educated than their husbands, and the ratio of educational level of husband and wife was higher than previous research findings. A large number of producers and their wives have taken off-farm work, and women tended to spend more time in off-farm employment. Only 6.1 percent of producers’ children had completed tertiary education and the majority of all sons were working on the farm. Partnership was found to be the major type of property ownership and inter-generational transfer of the property was the future plan. The producers who were from a non-farm upbringing and who had already taken up off-farm work intended to leave their properties at some time in the future. With the running of the farm business , 35 percent of rural women worked full-time in partnership with their husbands, and 42 percent worked part-time. However, 23 percent of rural women were homemakers and were not involved in running the farm business. The association between decision-making of husband and wife and situational factors such as ownership, involvement in farm tasks, record-keeping, education, on-farm upbringing and age were analysed. Joint involvement of wives in decision-making was to be related to ownership, farm tasks and record-keeping. However, husbands were more likely to take a major role in decision-making if they were more educated and had an on-farm upbringing. Age was found to be a factor affecting joint decision-making, although this result conflicted with findings of earlier research. The opinions of the farm community in identifying the problems of the specific small area in the Lockyer Valley were revealed. Lantana was the most severe weed problem in the whole catchment. The catchment area also had problems with wattle. The recommended control method of lantana was replacement by improved pasture, but it was adopted by few primary producers. Soil erosion in the form of gullies, bank erosion, sheet erosion, salinity and flooding were some of the problems perceived by the local community. Regular ‘slash and burn’ was practised by most of the producers. This is one of the causes of land degradation. Bore, creek and river, and dam were the main water sources for farm supply and irrigation. Only 60 percent of bored had adequate water supply and good water quality. Farm dam and creek/river sources were less reliable due to the inadequate availability of water. Consequently, operators at about half the cropped farms had to stop growing some vegetables which were previously commercially successful. Within the context of farm family needs, emphasis was placed on conservation of water, because of the erosion and water problems. The community’s opinion on community development activities emphasised the involvement of farm families. Finally, suggestions for the extension program which should be emphasised on rural development by means of community participation were included. The bases for further studies was also provided in this report.

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Målet med den här studien var att undersöka kiselalger och dess eventuella missbildningar i tre vattendrag i södra Sverige - Höje å, Skivarpsån och M42. Kiselalger används som bioindikator för vattenkvalitet i hela Europa, men de befintliga kiselalgsindexen visar inte eventuell förekomst av miljöfarliga ämnen. Det har dock visats att en förekomst > 1 % av missbildade kiselalger indikerar påverkan av miljöfarliga ämnen, såsom pesticider och tungmetaller. Denna studie är en av få som har undersökt kiselalgers missbildningar i vattendrag som är mer eller mindre påverkade av herbicider. Sex prov från varje vattendrag analyserades - kiselalger räknades och identifierades till artnivå och missbildningar dokumenterades och kategoriserades. Vattendragen delades in efter PTI (Pesticide Toxicity Index), där Höje å hade lägst PTI och ansågs minst påverkad av herbicider. Skivarpsån och M42 hade högre PTI, och ansågs därför ha en högre herbicidpåverkan. Det fanns en signifikant skillnad i missbildningsfrekvens vattendragen emellan, den kunde dock inte kopplas till PTI. Både Höje å och M42 hade > 1 % missbildningar. Skivarpsåns missbildningsfrekvens var < 1 % trots vattendragets relativt höga PTI. Det är möjligt att missbildningsfrekvensen bättre hade reflekterat PTI om herbicidprovtagningen skett någon månad tidigare, då herbicidhalter kan variera och kiselalger har visat sig kunna spegla ett vattendrags mående upp till tre månader bakåt i tiden. En annan förklaring till en varierande missbildningsfrekvens kan vara en lika varierande artsammansättning. Vissa arter är mindre “benägna” att missbildas än andra - ett prov som domineras av sådana skulle därför kunna innehålla få missbildningar trots eventuell miljögiftspåverkan. Det krävs dock ytterligare studier för att bättre förstå kiselalgers missbildningar i förhållande till herbicider.

The need for an Anthropocentric Development Evaluation stems from the inability of development theory and praxis, which has informed the past Development Decades, to ameliorate abject poverty experienced by most people throughout the world. Emanating from a hermeneutical-interpretist epistemology the fundamental argument of an Anthropocentric Development Evaluation is that people and the crucial aspects of their humanity should be the central focus in development and evaluation processes. Thus, taking the people-centred approach to development as its starting point, an Anthropocentric Development Evaluation draws attention to the marginalised, particularly the poor, the rural poor, resource-poor primary producers, women and their households. An Anthropocentric Development Evaluation also argues for an actor-orientation to Development Evaluation to emphasise the situational, yet individual behaviour, of people. Alongside such an approach, lies the significance of culture and people's knowledge for development, as well as the limitations, risks, uncertainties and vulnerabilities people face as a consequence of their humanity. These may influence the extent to which they participate in spontaneous or imposed development initiatives. An Anthropocentric Development Evaluation then comparatively assesses three sets of similar, yet different, methodologies using people and aspects of their humanity described above as the focus for that assessment. The methodologies assessed include Action Research, Social Impact Assessment and the Complementary Rural Development Field Tools. The purpose of doing so is to obtain a suitable medium through which to test the focus of an Anthropocentric Development Evaluation in a development setting. The testing of an Anthropocentric Development Evaluation in a development setting is done first by providing an Anthropocentric Development Evaluation of aspects of life of people living in the community of Nyanyadu in KwaZulu-Natal. Social Impact Assessments using the focus of an Anthropocentric Development Evaluation are then made of two development initiatives in respect of the people of Nyanyadu. These two initiatives are a nutrition and social development programme and the national land reforms. The purpose of all these evaluations is to examine the extent to which people and their humanity are seen to be crucial in development processes. / Development Administration / D.Litt. et Phil. (Development Administration)

The need for an Anthropocentric Development Evaluation stems from the inability of development theory and praxis, which has informed the past Development Decades, to ameliorate abject poverty experienced by most people throughout the world. Emanating from a hermeneutical-interpretist epistemology the fundamental argument of an Anthropocentric Development Evaluation is that people and the crucial aspects of their humanity should be the central focus in development and evaluation processes. Thus, taking the people-centred approach to development as its starting point, an Anthropocentric Development Evaluation draws attention to the marginalised, particularly the poor, the rural poor, resource-poor primary producers, women and their households. An Anthropocentric Development Evaluation also argues for an actor-orientation to Development Evaluation to emphasise the situational, yet individual behaviour, of people. Alongside such an approach, lies the significance of culture and people's knowledge for development, as well as the limitations, risks, uncertainties and vulnerabilities people face as a consequence of their humanity. These may influence the extent to which they participate in spontaneous or imposed development initiatives. An Anthropocentric Development Evaluation then comparatively assesses three sets of similar, yet different, methodologies using people and aspects of their humanity described above as the focus for that assessment. The methodologies assessed include Action Research, Social Impact Assessment and the Complementary Rural Development Field Tools. The purpose of doing so is to obtain a suitable medium through which to test the focus of an Anthropocentric Development Evaluation in a development setting. The testing of an Anthropocentric Development Evaluation in a development setting is done first by providing an Anthropocentric Development Evaluation of aspects of life of people living in the community of Nyanyadu in KwaZulu-Natal. Social Impact Assessments using the focus of an Anthropocentric Development Evaluation are then made of two development initiatives in respect of the people of Nyanyadu. These two initiatives are a nutrition and social development programme and the national land reforms. The purpose of all these evaluations is to examine the extent to which people and their humanity are seen to be crucial in development processes. / Development Administration / D.Litt. et Phil. (Development Administration)