L’intérêt que porte la communauté scientifique ainsi que politique aux les services écosystémiques et à leur résilience face aux changements globaux (environnementaux ou sociétaux) en cours est grandissant, ce qui se reflète par le nombre d’études à ce sujet, le rapport d’évaluation des écosystèmes pour le millénaire et la mise en place d’un groupe de travail sur la résilience (« Resilience Alliance »). Les définitions de la résilience sont elles aussi très variées, avec des concepts tels que la résistance, la résilience spécifique (« de quoi à quoi ? »), la résilience générale, l’adaptabilité et la transformabilité, que nous nous sommes appropriés dans le but de développer un cadre conceptuel et méthodologique pour étudier la résilience de la fourniture de services écosystémiques, en particulier dans le but de comparer les potentiels de résilience des différents types de prairies subalpines du col du Lautaret (Hautes-Alpes, France) pour un ensemble de services sélectionnés. Nous avons proposé deux approches pour évaluer les potentiels de résilience des différents états dans lequel peut se trouver un socio-écosystème, en considérant la résilience comme la capacité d’un système à maintenir une fourniture stable de services écosystémiques (composante résistance) mais aussi sa capacité à l’adapter (différentes composantes selon le degré d’adaptation : résilience, transition, transformation). Une première étape d’évaluation d’un ensemble de services d’intérêt sur la zone d’étude est suivie d’une première analyse de la résilience de chacun de ces services spécifiquement, basée sur l’évaluation de « gammes opérationnelles » pour chaque service, définies comme les gammes de valeurs que peut prendre le dit service dans un état donné du socio-écosystème. L’échelle organisationnelle à laquelle ces gammes sont évaluées les relie aux différentes composantes de la résilience. Les résultats confirment l’intérêt de s’intéresser à la résilience spécifique de chaque service, car leur profil de résilience sont différents, c’est-à-dire que les prairies aux plus forts potentiels ne sont pas les même d’un site à l’autre, bien que dans tous les cas les potentiels de résilience soient plutôt forts, au contraire des autres potentiels.La deuxième analyse part de l’hypothèse théorique que la diversité des traits de réponse (hétérogénéité et redondance) améliore la résilience. Nous avons fait l’hypothèse que, lorsque les traits de réponse sont ceux utilisés pour modéliser les services écosystémiques, la diversité fonctionnelle d’une communauté végétale peut-être reliée à sa résilience générale en termes de services écosystémiques. Nous avons relié plusieurs mesures de la diversité fonctionnelle aux potentiels de résilience (entropie et diversité fonctionnelle dans leur dimension α et β, redondance et complémentarité des groupes fonctionnels). Cependant, les résultats obtenus par l’analyse des prairies du Lautaret nous amènent à réfuter l’hypothèse proposant que la diversité fonctionnelle des communautés végétales permet d’expliquer le profil de résilience des services écosystémiques analysés, car ils ne concordent pas avec les profils de résilience trouvés par l’approche des gammes opérationnelles. Au final, nous préconisons d’utiliser l’approche des gammes opérationnelles, qui permet de connaître le profil de résilience de chaque service, dans le cadre d’étude portant sur la capacité d’un socio-écosystème à maintenir la fourniture de ses services écosystémiques. Cette approche peut de plus être enrichie d’une approche de scénarisation qui permettrait de déterminer « à quoi » la fourniture de chaque service est résiliente. / As evidenced by the number of studies on the subject, the recent millennium ecosystem assessment and the establishment of a working group on resilience (« Resilience Alliance »), the interest of the scientific community in ecosystem services and their resilience in the face of global change (environmental or social) is steadily increasing. Definitions of resilience are highly varied, and we used concepts such as resistance, specific resilience (« of what to what ? »), generalised resilience, adaptability and transformability to develop a conceptual and methodological framework to study the resilience of ecosystem service provision. This conceptual framework was applied to compare the potential resilience of differing sub-alpine grasslands types in three local government areas in the area of the Col du Lautaret (Hautes-Alpes, France) for a number of locally and regionally important ecosystem services. We proposed two approaches for evaluating the potential resilience of the different states in which a socio-ecosystem can exist, by considering resilience as the capacity of a system to maintain a stable provision of an ecosystem service (resistance component), as well as its capacity to adapt this provision if needed (components of resilience, transition, transformation depending on the degree of adaptation). A first stage of the quantification of ecosystem services was followed by an initial analysis of each of these services via the evaluation of their « operating ranges », defined as the range of values that a service can take given a particular state of the socio-ecosystem. The organizational scale at which these ranges are evaluated links them to other components of resilience. Our results confirm the utility of considering the specific resilience of each service, as the profiles of their resistance are different. In particular, the types of grasslands with the highest resilience component potential are not the same from one site to another, even though in all cases these resilience component potentials are rather high as compared to other components potentials. The second analysis is based on the theoretical hypothesis that it is the increasing diversity of response traits (heterogeneity and redundancy) which increases resistance. We hypothesised that, when it is response traits that have been used to model ecosystem services, the functional diversity of a plant community can be linked to its overall resistance in terms of ecosystem services. We linked a number of measures of functional diversity to resilience potential, including the α and β dimensions of entropy and functional diversity, and the redundancy and complementarity of functional groups. The obtained results for the grasslands at Lautaret lead us to reject the hypothesis which proposes that the functional diversity of plant communities can be used to predict the patterns of resilience of the analysed ecosystem services, as these do not correspond to the patterns of resistance obtained from the approach using operating ranges. Finally, we suggest that to assess the capacity of a socio-ecosystem to maintain the provision of ecosystem services, our approach using operating ranges is preferable as it allows for the quantification of the resistance profile of each service. This approach could be further developed using scenario building so as to determine « to what » the provision of each service is resistant.

Os manguezais de Bertioga localizam-se próximos ao limite sul de distribuição dessa comunidade vegetal na costa brasileira e no hemisfério sul. Esses bosques são compostos por três espécies: Rhizophora mangle L., Avicennia schaueriana Stapf & Leechman e Laguncularia racemosa Gaertn f. e apresentam estrutura pouco desenvolvida. O manguezal do Rio Iriri possui um diâmetro médio de 8,48 cm, altura média de 6,55 m, densidade de 216 ind/0,1 ha e área basal de 1,29 m2m2/0,1 ha. Já no Rio ltapanhaú, .o diâmetro médio do bosque é de 10,41 em, com altura média de 6,83 m, densidade de 173 ind/0,1 ha e área basal de 1 ,69 m2/0,1 ha. Estimativas de biomassa nos dois locais de estudo resultaram em valores de 42,3 t/ha para o Rio iriri e 59,7 t/ha para o Rio Itapanhaú e a produção anual de madeira foi de 3,6 e 1,9 t/ha respectivamente. Esse baixo desenvolvimento estrutural é provavelmente devido às baixas temperaturas alcançadas no inverno e aos diversos estresses aos quais estão submetidos esses bosques em função das atividades humanas desenvolvidas na região. A produção de serapilheira desses bosques reflete seus baixos índices estruturais, embora trate-se de bosques de franja inundados duas vezes ao dia por marés de mais de 1 m de amplitude. A taxa média anual de produção de serapilheira foi de 5,6 t/ha no Rio lriri e 4,6 no Rio Itapanhaú. Padrões sazonais foram evidentes para os diversos componentes da serapilheira assim como uma sequência temporal das diversas fases fenológicas. As folhas apresentaram maior produção durante o verão. As flores mostraram picos no final dessa estação seguidas de picos de propágulos no outono. A queda de madeira apresentou maiores taxas principalmente nos meses de inverno. Os fatores que controlam essa sazonalidade estão provavelmente associados à temperatura e pluviosidade. Nesses manguezais a renovação desse material é alta, apresentando baixas quantidades de estoque de serapilheira no sedimento, cujos valores variam de 50 a 164 gPS/m2. Essa renovação se dá através da decomposição, que é bastante rápida, com taxas diárias médias de 0,006 para Rhizophora, 0,011 para Laguncularia e 0,015 para Avicennia. Além da diferença entre as espécies, foi observada uma diferença entre as estações e os sítios. As taxas do verão foram significativamente mais altas que as do inverno. Além disso, o Rio Iriri apresentou taxas médias mais elevadas que o Itapanhaú. Embora o processo de decomposição seja intenso nesses manguezais pela existência de condições favoróveis, a maior parte da renovação se dá através da exportação da serapilheira pelo movimento das marés. A partir da elaboração de um modelo ecológico da dinâmica da serapilheira incluindo sua produção, estoque e decomposição, foi possível estimar essa exportação cujos valores estão em torno de 0,7 gPS/m2 por dia com uma exportação acumulada anual de cerca de 2,5 tPS/ha, o que significa que estes manguezais exportam aproximadamente 50 por cento da serapilhelra que produzem. Essa dinâmica da serapilheira influencia também a ciclagem de nutrientes nesse ecossistema. Para compensar a exportação de materiais esses manguezais apresentam retranslocação de nutrientes como o nitrogênio e o fósforo, mecanismo no qual esses elementos são reabsorvidos da folha antes de sua queda. A imobilização, outro mecanismo para conservar nutrientes durante a decomposição, não foi significativa nesse estudo, ocorrendo apenas com nitrogênio em folhas de Laguncularia. Apesar da retranslocação registrada nesses bosques, tanto para o nitrogênio quanto para o fósforo, esses manguezais não se mostraram eficientes no uso de nutrientes, provavelmente, porque estes estejam disponíveis no sedimento em quantidades adequadas. A variação anual da concentração de nutrientes nas folhas da serapilheira mostrou um padrão sazonal com maiores valores no inverno e menores no verão. Já as folhas verdes não apresentam essa sazonalidade tão nítida:o que ocorre, portanto, é uma maior retranslocação durante a época de maior produção de folhas, mantendo os teores desses nutrientes na copa. / The mangroves in Bertioga estuary are mixed forests composed by three species: Rhizophora mangle L., Avicennia schaueriana Stapf & Leechman and Laguncularia racemosa. Gaertn f. Both study sites are frequently flooded by tide waters and can be classified as fringe forests, according to the physiographic types. The Rio Iriri site had a DBH of 8,48 cm, and a mean height of 6,55 m, density in this site was 216 trees/0,1 ha and the basal area was 1,29 m2/0,1 ha. In Rio Itapanhaú, mean DBh was 10,41 cm, with mean height of 6,83 m, density of 173 trees/0,1 ha and basal area of 1,69 m2/0,1 ha. Based on the structural parameters it is possible to see that DBH and tree height of these forests are equivalent to other fringe sites, but density and basal area are much lower. The DBH increment was similar to measurements presented in other studies. However wood production was much lower, because of low density. Biomass estimate of each site forest were: for rio Iriri the biomass was 42.3 t .ha-1 while in rio Itapanhaú it was 59.7 t. ha-1. Mean annual littertall rates were 5.6 t.ha-1 .yr -1 in Rio Iriri and 4.6 t.ha-l.yr-1 in Rio Itapanhaú. However, these forests are fringe mangroves which normally have higher production rates. In this study litter fall production was seasonal with a trend of alternate peaks for the various components which appears to be a sequence within the year. Leaf fall is higher in the summer which is the rainy season (from November through February) followed by the miscellaneous peak in the autumn (from March through May) while the period of higher wood production is from June to October. This pattern suggests a coordination among phenological phases. The factors controlling those variations are still not clearly established. Environmental conditions related to rainfall and temperature are the most probable responsibles for this influence. The decomposition potential of the mangrove sites in Bertioga region (23º51\'5) was high and this might be due to high temperature associated to high rainfall and frequent flooding that create good conditions (hot and humid environment) to accelerate the organic matter degradation. Species showed different decomposition rates. The highest value of k were observed for A. schauerianna (0.015 d-1) followed by L. racemosa (0.011 d-1 ). The lowest value of k occurred in R. mangle (0.006 d-1 ). Brazilian studies of litter decomposition with the same species showed the same gradient of species specific rates. Those differences can be explained by differences in the resource quality. Chemical composition of leaf material is very important in determining its decomposition rate. There was also a significant difference in decomposition rates among species and between sites and seasons. Iriri had higher decomposition rates than Itapanhaú. Summer season had higher decay rates than winter. The processes of decomposition are regulated by the combined effects of the resource quality and the physico-chemical environment on the community of decomposer organisms. According to these main controlling factors, differences observed among species should be attributed to differences in substrate quality, while differences among sites or seasons would be related to different environmental conditions. Seasons differences would be more related to climate features while site differences in this study would be more determined by edaphic features. Although there was an increase in nutrient percentage during decomposition, there was not an increase in their absolute concentration or net accumulation. In Bertioga mangrove forests immobilization was low or absent perhaps because the studied sites are fertiles. In addition, it is only observed in Laguncularia leaves because it is the species with lowest nitrogen concentration what would be a limiting factor. The high content of nitrogen in Rhizophora leaves could be the reason why this nutrient had no net immobilization in this study. Apparently, the absence of phosphorus immobilization could be its availability in both ways, plant tissue and sediment. Mean values of litter standing stock ranged from 50 to 164 g.m-2 throughout the year which are low values, but considering that both are fringe sites it would be expected. Seasonal patterns of litter standing crop can be related to seasonal patterns of litter production, decomposition or hydrological variations. Since in Bertioga decomposition plays a small role because most of litter is removed and hydrology does not show a marked seasonal pattern, litter export and stock reflect the seasonality of litter production and may be a little modified by variations in tidal height. This is not valid for wood component that showed a different behaviour because it is not very influenced by export. Litter turnover rates of this study ( 5.1 and 4.7 yr-1) are higher than other values found in other mangrove forests. The values obtained for leaf fall (14.92 to 24.22 yr-1) in this study are very high even for fringe forest. Analysis of turnover rate for each month indicates that these rates vary throughout the year. especially for leaf fall. The period of higher turnover rates seems to be related to higher litterfall rates, but it may be also an interaction with the variation of tidal amplitude and decomposition. It is possible to see that there is a coincidence of the months of higher turnover rates with the months of higher tidal amplitude. Since measurement of litter export is very difficult because water movements are very complex in a mangrove site and due to the importance of litter dynamics to the tunction of a mangrove ecosystem. the development of a litter dynamics model was useful to understand those processes and organic matter fluxes and to the estimate of export rates. The litter model includes littertall as the input of organic matter, litter standing crop as the storage of organic matter and decomposition and export as outputs of organic matter from the system. Based on these figures it is possible to roughly estimate an annual export of 2,5 t.ha.yr -1. The conclusion is that in these mangrove forests at least 50 per cent of its production is exported by tides. Nutrient content in canopy of mangroves in Bertioga is high and although retranslocation takes place, nutrient concentrations in litterfall are still high. C:N of leaf litter in these forests are low and decomposition should not be nutrient limited. Then litter decay occurs fast with low or none immobilization. These are characteristics of sites with high availability of nutrients. In these forests, although nutrient use efficiency is not very high, nutrient recycling is occurring via retranslocation and not via immobilization during decomposition probably because they are fringe forests. The high retranslocation rates could be a mechanism to prevent loss of nutrients by export. Another important characteristic of these mangroves was the seasonal pattern of nutrient cycling. Nutrient content of leaf fall varies throughout the year with high concentration during winter. Retranslocation also showed a seasonal pattern with higher rates in the summer, resulting in lower nutrient levels in leaf litter and the consequence is a higher nutrient use efficiency in this period of leaf production.

Global demand for agricultural products is an increasingly important driver of deforestation in the Amazon Basin. This dissertation examines the consequences of agricultural expansion for stream ecosystems in the southern Amazon's agricultural frontier. At regional scales, the removal of watershed forest cover is known to change the energy balance and influence hydro-climatic cycling by altering stream flow, regional rainfall patterns, and land surface temperatures. At the landscape scale, these physical changes may be further exacerbated by land management practices that lead to the degradation of riparian forest buffers; decreases in connectivity; changes in the amount of light, nutrient, and sediment inputs; and decreases in water quality. Together, land use and management influence the quality and distribution of aquatic habitats within stream networks, potentially decreasing stream biotic integrity and resilience to further disturbances. Brazil's Mato Grosso state is one of the most actively expanding agricultural frontiers in the world and represents an ideal case study for examining the linkages among tropical deforestation, agricultural expansion, and the conservation of freshwater ecosystems. Mato Grosso accounted for 40% of deforestation in the Brazilian Amazon during the early 2000s - primarily due to the expansion of soybeans and cattle ranching. Deforestation rates have since dropped throughout the Amazon, but there is a lack of spatially explicit information about the land use transitions accompanying this decline. To address this gap, I combined government data on deforestation and production with the MODIS satellite time series to quantify the spatial-temporal dynamics of land use change in the region. Although agricultural expansion during this period slowed with declining commodity prices, the decline in deforestation is partly explained by a shift from soybean expansion into forests (26% of expansion from 2001-2005) to expansion into already cleared pasture lands (9% of expansion form 2006-2010). Beyond documenting these trends, the resulting dataset is a critical first step in evaluating the influence of land use and land use history on freshwater ecosystems at multiple scales. In the headwaters region of the Xingu River Basin, the proportion of small watersheds (microbasins) dominated by agriculture (>60% of area) increased from 20 to 40% from 2001 to 2010. At the same time, the stream network became increasingly fragmented by the removal of riparian forest buffers and installation of farm impoundments. I used high resolution satellite data (ASTER) to produce the first landscape-level documentation of farm impoundments in the region, mapping approximately 10,000 impoundments (one per 7.6 km of stream length) in 2007. At the catchment scale, I collected field data in 12 headwater streams to examine the effect of land management on instream water quality. Watershed forest cover (from MODIS), the density of impoundments (from ASTER), and the percent forest in upstream riparian buffers (from Landsat) were all associated with substantial increases in stream temperature. These increases in fragmentation and water temperature may have large cumulative effects on the stream network and reduce the ability of downstream protected areas to conserve freshwater resources. At the scale of the Amazon Basin, my analysis indicates that 30% of indigenous lands and protected areas are highly vulnerable to future reductions in hydrologic connectivity, simply because of their location within their watersheds. These impacts could be substantially mitigated through enforcement of existing legislation to protect riparian buffers and new regulations to limit the number of impoundments in emerging agricultural landscapes.

The high northern latitudes of North America are undergoing rapid climatic change with acute impacts to the ecosystems in which millions of songbirds breed each year. The goal of this dissertation is to improve understanding of how concurrent and interacting changes in environmental and land surface conditions influence annual movements and habitat selections of long distance migratory birds who must navigate the mosaic of changing North American ecosystems. Chapter 1 presents novel automated bioacoustic methods for estimating arrival dates of the songbird community to their arctic breeding grounds. Automated acoustic networks could vastly expand the spatiotemporal coverage of wildlife observations. However, the enormous datasets that autonomous recorders typically generate demand automated analyses that remain largely undeveloped. Chapter 1 demonstrates novel machine learning and signal processing techniques for estimating songbird community arrival dates near Toolik Field Station which agreed well with traditional survey estimates and were strongly related to the landscape’s snow free dates. Daily variations in vocal activity were more strongly influenced by environmental conditions prior to egg-laying dates. The success of the approaches presented in Chapter 1 indicate that variation in songbird migratory arrival can be detected autonomously. Widespread deployment of this advance could provide avian monitoring on a scale large enough to enable global-scale understanding of how climate change influences migratory timing of avian species. Chapter 2 examines potential future changes in habitat suitability for for two songbirds breeding throughout North America’s high northern latitudes – a tundra-nesting species (Lapland Longspurs (Calcarius lapponicus)) and a shrub-nesting species (White-crowned Sparrows (Zonotrichia leucophyrs)). By the late 21st century, models based on both climate and vegetation projected habitat suitability for Lapland Longspurs decreased across nearly all of the study domain (54-96%), while that for White-crowned Sparrows decreased in 69% of North America’s high northern latitudes. For both species, currently unsuitable habitats in northern Canada and Alaska are projected to provide suitable breeding habitat in the future. In contrast, models based solely on climate showed more drastic declines in habitat suitability for both species (Lapland Longspur, ~100% and White-crowned Sparrow ~80%). This discrepancy between model projections demonstrates that the future availability of suitable songbird breeding habitat for both species will be strongly dependent on how both the vegetation and climate– as opposed to climate alone - of northern ecosystems respond to ongoing climate change. Chapter 3 investigates the environmental and ecological drivers of migratory movements of songbirds breeding at high northern latitudes. For North America alone, there is overwhelming evidence of major shifts in seasonality of meteorological conditions, snow cover, and vegetation phenology. Few studies have focused on how this suite of changes impacts long distance migratory species that annually navigate throughout the spatially and temporally dynamic mosaic of ecosystems because of technological constraints in animal tracking. However, recent advances in GPS technology have generated units small enough to be placed on songbird species. In 2016-2018 a total of 55 American robins (Turdus migratorius) were tracked during their spring migration through the Canadian boreal forest en route to their breeding grounds. We found a significant trend towards earlier arrival of robins to the Canadian boreal forest over the past quarter-century, consistent with advances in spring environmental conditions. Robin stopover timing at our tagging site was delayed in response to later seasonal snowmelt, but triggered by adverse environmental conditions. Individuals breeding in regions with shorter snow-free seasons moved faster than individuals breeding in areas with longer snow-free seasons and selected locations with less favorable environmental conditions. Overall, arrival timing to breeding grounds was negatively related to snow depth and positively related to snowmelt timing. Migratory movements and timing of American robins are highly tied to seasonal environmental dynamics en route to their breeding grounds. Our findings present a unique, mechanistic understanding of how migratory birds navigate highly dynamic ecosystems. In light of rapid global change, the use of multi-disciplinary, spatially explicit approaches similar to the ones used in this dissertation will be critical for understanding how avian taxa breeding at high northern latitudes may respond to ongoing and future change. This is important for investigating both regional and global impacts because species breeding in arctic-boreal zones perform key ecosystem services around the globe.

Notions of ‘wildness' are increasingly relevant to upland management discussions in the Scottish Highlands as several conservation-focused estates embrace a ‘wildland management ethos'. However, while a range of wildland conservation initiatives have embarked upon pathways towards ‘rewilding', this research demonstrates that, although members of this creative conservation movement are widely perceived to share a common vision, they prioritise markedly different wildland qualities. Through a series of triangulated phases, this research explores this ‘spectrum of wildness' and examines the conceptual coherence of wildland restoration discourses. Twenty semi-structured scoping interviews with key stakeholders associated with Scotland's wildest places provide the foundations for an adapted Delphi model, incorporating a Q-methodology study, which utilises insights from seventeen large upland land-holdings to interrogate the disparate discourses associated with Scotland's emergent wildland movement. A taxonomy of management approaches is presented based upon (i) different conceptions of ‘wildness', (ii) differing degrees of concern for ecological and cultural integrity, (iii) conflicting beliefs about the degree of management intervention appropriate and (iv) fundamentally divergent underlying environmental ideologies. A further twenty-three semi-structured interviews exploring wilderness restoration frameworks in the USA, New Zealand and parts of Europe provide an international perspective on Scotland's distinctive approach to wildland management and demonstrate the challenges of multi-dimensional wilderness frameworks which grow out of conflicting mandates; most notably, a critical faultline exists between restoring ‘wildness' (focussed on processes) and naturalness (focussed on endpoints). Given that practical tensions can arise from these different ideological perspectives, understanding and accommodating the social and cultural dimensions which shape multiple (re)wilding discourses is considered critical. As such, place-specific and endogenous social representations are called for, in which wild land is both a physical place and a cultural ideal, and in which (re)wilding comprises a heterogeneous mix of different wilds. This research also critically reflects upon how cultural landscapes with wild qualities present opportunities for rethinking the historical and cultural dimensions of established wilderness values. By exploring the framing of ‘wild' in Scotland's wildland initiatives, a postmodern wildlands narrative which negotiates the conceptual challenges of (re)wilding in a storied, cultural landscape is presented.

L’anthroposystème pastoral du Ferlo sénégalais évolue dans un milieu historiquement négligé par les politiques agricoles en raison de ses caractéristiques biophysiques particulières, peu favorables à l’agriculture et à une forme de mise en valeur autre que l’élevage extensif, incluant une transhumance. Celui-ci permet d’exploiter des ressources très variables dans l’espace et dans le temps. Cette primauté de l’élevage itinérant est de nos jours de plus en plus contestée par le développement de l’agriculture dans un contexte marqué par l’amélioration des conditions de la pluviosité dans tout le Sahel ouest-africain, de l’épuisement des terres du Bassin aracohidier et de la multiplication des aménagements agricoles au niveau de la vallée du fleuve Sénégal. En combinant l’analyse d’images de télédétection pour la cartographie d’évolution de l’occupation du sol par le couvert végétal, l’étude de la flore et du paysage végétal et l’exploitation d’enquêtes dans les villages et les campements du Ferlo, ce mémoire de thèse tente de cerner la géographie de la vulnérabilité des populations rurales et des écosystèmes qu’elles utilisent. Ainsi les éleveurs et les pasteurs évoluent-ils avec des stratégies d’adaptation quotidienne dans ces milieux du Sénégal intérieur marqués par l’instabilité écologique profonde et par les transformations à l’oeuvre dans la société rurale sénégalaise. Ces changements socio-environnementaux considérables contribuent ainsi à la dynamique des paysages végétaux et par-delà pose la question de la dégradation des écosystèmes. / The pastoral anthroposystem of Senegalese Ferlo evolves in an environment historically neglected by agricultural policies because of its characteristics particular biophysics, unfavorable to the agriculture and to the shape of development other than the extensive breeding. This primacy of the itinerant breeding is nowadays more and more disputed by the development of the farming in a context marked by the improvement of the conditions of the rainfall in West-African Sahel, soil depletion in the Groundnut Basin and the multiplication of agricultural development at the valley of the Senegal River. By combining the analysis of remote sensing imagery for mapping land cover changes by the vegetation cover, the study of flora and vegetation landscape and the exploitation of the investigations in villages and camps, this thesis attempts to define the geography of the vulnerability of rural populations and ecosystems which they use. So, pastoralists evolve with daily adaptation strategies in these circles inside Senegal marked by deep ecological instability and by the transformations at work in the Senegalese rural society. These socio-environmental changes contribute to the dynamics of plant landscapes and raise the question of ecosystem degradation.

O impacto da poluição luminosa sobre o homem e o meio ambiente é fonte de preocupação crescente por parte dos ambientalistas. Ao mesmo tempo a população demanda quantidades crescentes de iluminação artificial para aumentar a segurança e o conforto. Com a finalidade de satisfazer a necessidade humana de iluminação com equipamentos de impacto mínimo sobre o ecossistema, realizamos o teste de diferentes equipamentos comerciais de iluminação com diferentes lâmpadas e utilizando filtros seletivos de comprimento de onda da radiação. A hipótese básica do experimento é que o homem e os insetos apresentam sensibilidade visual diferente por comprimento de onda e que a atração da iluminação artificial sobre os insetos não representa um fototropismo. Os insetos utilizam a radiação artificial como baliza. Na verdade, utilizam o contraste entre radiação de onda curta (UV e violeta) e onda média (azul e verde) para identificar o espaço no qual voar. Selecionando os comprimentos de ondas da iluminação artificial é, portanto, possível minimizar a atração. Durante dois anos foi realizada uma campanha de coleta de insetos utilizando armadilhas luminosas. Quatro tipos de sistema de iluminação foram comparados: lâmpada vapor de mercúrio a alta pressão (Hg); lâmpada a vapor de sódio a alta pressão (Na) sem e com filtro (Hg_f; Na_f) e uma armadilha sem lâmpada. Os resultados do experimento mostram que a armadilha Hg atraiu em média 70 insetos; a armadilha Na 45; a armadilha Hg_f 23 e a armadilha Na_f 16, contra apenas 8 no testemunho. Os resultados confirmam amplamente as hipóteses básicas e oferece um poderoso instrumento para a elaboração de sistemas de iluminação de impacto no que tange os insetos / The impact of light pollution on man and on the ecosystem is a rising concern among ecologists however, in the same time the human population is demanding more lighting for safety and comfort. In order to satisfy human lighting needs with a minimum impact on the ecosystem, manly on insects, we tested commercial equipments using different types of lights and using selective wavelength filters. The hypothesis underlying the experiment was that humans and insects have a different visual sensibility for wavelength, but insect attraction for lighting is not just a phototropism. Insects use artificial lighting as a landmark for navigation and contrast between short wave (UV and blue) and medium wave (green) radiation is used to screen the space. Selecting wavelength emission of the lighting systems could be possible to minimize insect attraction. In a two years long campaign we undertook insect collection tests using insect traps. We compared four lighting systems: high-pressure mercury bulb (Hg), high-pressure sodium bulb(Na) without and with UV filter (Hg_f; Na_f) and a lighting fixture with an insect trap without bulb as a control. The results of the test have shown that Hg lamp attracted an average of 70 insects by night, Na lamp 45, Hg_f 23, Na_f 16 ad Test lamp 8. The result confirm the proposed hypothesis and can be used in the elaboration of minimum impact lighting fixtures.

Deutscher Akademischer Austausch Dienst / Diante da crise ambiental global, os ecossistemas tornam-se cada vez mais vulnerÃveis, e consequentemente os benefÃcios por eles ofertados, conhecidos como serviÃos ecossistÃmicos. Os ServiÃos EcossistÃmicos influenciam de maneira direta e indireta a promoÃÃo de bem-estar humano. Seus benefÃcios atravessam fronteiras, mas a sua produÃÃo pode acontecer de maneira local, cujo processo ainda à pouco entendido pelos cientistas. Durante anos, tÃm sido negligenciados, principalmente pelos paÃses com pouco conhecimento e interesse sobre sua prÃpria biodiversidade. PorÃm, o desafio de se conviver em um planeta finito e com uma populaÃÃo mundial cada vez maior anuncia um cenÃrio em que o impacto crescente sobre o uso dos recursos naturais impulsionarà a necessidade de se investir em uma gestÃo eficiente sobre sua alocaÃÃo. O presente trabalho parte da hipÃtese de a mensuraÃÃo do bem-estar, pela perspectiva do desenvolvimento sustentÃvel, deve ser composta por indicadores que contemplem a integraÃÃo entre o bem-estar humano e os serviÃos ecossistÃmicos. O objetivo geral da pesquisa foi propor um conjunto de indicadores que retrate, pela perspectiva do desenvolvimento sustentÃvel, a importÃncia da inserÃÃo dos serviÃos ecossistÃmicos de provisÃo na mensuraÃÃo do bem-estar em Ãreas degradadas. Essa relaÃÃo traz em si o Ãbvio: a importÃncia dos serviÃos ecossistÃmicos para o bem-estar humano. Baseando-se em uma releitura de Prescott-Allen (2001) e adaptando para a realidade local, foi desenvolvido um conjunto de Ãndices e indicadores, em diferentes dimensÃes, que resultaram em dois Ãndices: Ãndice de Bem-Estar Humano (IBEH) e Ãndice de Bem-Estar EcossistÃmico (IBEE). O IBEH à composto por cinco dimensÃes (SaÃde e PopulaÃÃo, Riqueza das FamÃlias, Conhecimento e Cultura, Comunidade e Equidade) e quinze indicadores, enquanto o IBEE à constituÃdo por cinco dimensÃes (Terra, Ãgua, Ar, Biodiversidade e Uso dos Recursos) e sete indicadores gerando assim um framework que reproduz o seu estado e suas inter-relaÃÃes. A validaÃÃo do IBEH e do IBEE foi realizada na comunidade do SÃtio do Brum localizado no bioma Caatinga no estado do CearÃ, Brasil. Desconhecido para muitos, a Caatinga està em acelerado processo de degradaÃÃo intensificado pela mà gestÃo dos recursos ambientais bem como pelas condiÃÃes climÃticas da regiÃo. Como principais resultados o uso de Ãndices e indicadores em serviÃos ecossistÃmicos conseguiu capturar a relaÃÃo entre os serviÃos ecossistÃmicos e o bem-estar humano, alÃm de validar a capacidade dos indicadores escolhidos descreverem os sistemas sÃcio-ecossistÃmicos e a sua interaÃÃo. A escolha da aplicaÃÃo dos Ãndices em um bioma degradado e por diversas vezes pouco valorizado, como a Caatinga, revelou nÃo somente a importÃncia do impacto das aÃÃes antrÃpicas neste tipo de bioma, mas o vÃu que os cobre. Identificou-se uma comunidade que compreende sua realidade, almeja mudanÃas, possui visÃo de futuro coletiva, mas nÃo possui capacidade de provocar mudanÃas. Embora nÃo seja fÃcil agir em funÃÃo das preocupaÃÃes intergeracionais, mudanÃas somente ocorrerÃo quando as avaliaÃÃes de serviÃos ecossistÃmicos englobarem tambÃm as pessoas, algo que por sua vez envolve motivaÃÃes e limites cognitivos na aquisiÃÃo e processamento de informaÃÃes, essencial para garantir o bem-estar das geraÃÃes presentes e futuras, abordagem sugerida pelo framework em questÃo apresentado. / Given the global environmental crisis, ecosystems become increasingly vulnerable and therefore the benefits offered by them, known as ecosystem service. The ecosystem services influence directly and indirectly the promotion of human well-being. Its benefits cross borders, but its production can happen in a local way, which process is still poorly understood by scientists. For years, the ecosystem services have been neglected, especially by countries with little knowledge and interest about their own biodiversity. However, the challenge to live in a finite planet with a growing world population announce a scenario where increasing impact on the use of natural resources will drive the need to invest in efficient management of its allocation . This study starts from the hypothesis that the measurement of well-being by the sustainable developmentâs approach would include indicators that address the integration of human well-being and ecosystem services. The main goal of this research is present indices that portray, in a sustainable developmentâs approach, the importance of integrating provisioning ecosystem services in measuring of well-being in degraded areas. This interaction brings with it the obvious: the relevance of ecosystem services for human well-being. Taking into account the literature review, we adapted the Prescott-Allen model to make it appropriate for our study area. A set of indices and indicators were developed in different dimensions resulting in two indices: the Human Well-Being Index (HWBI) and the Ecosystem Well-Being Index (EWBI).The HWBI consists of five dimensions: Health and Population, Household Wealth, Knowledge and Culture, Community and Equity, and fifteen indicators. The EWBI also consists of five dimensions: Land, Water, Air, Biodiversity and Resource Use; and seven indicators. The interaction between these two indices generated a framework that shows the dependence between each of the variables analyzed. The proposed set of indicators was tested in Sitio do Brum community, located in the Caatinga biome in the state of CearÃ, Brazil. Unknown to many, the Caatinga is in a rapid degradation process due to mismanagement of environmental resources and the climatic conditions of the region. The main results of the use of indices and indicators for ecosystem services managed to capture the relationship between ecosystem services and human well-being, and to validate the ability of the chosen indicators to describe the socio-ecosystems and their interaction. The choice of application of the parameters in a degraded and often undervalued biome, such as the Caatinga, revealed not only the importance of the impact of human actions in this type of biome, but the veil that covers them. A community was identified, which understands its reality, craves for changes, has its own collective vision of the future, but has no ability to bring about change. Although it is not easy to act on the basis of intergenerational concerns, changes only occur when the assessments of ecosystem services also encompass people, which in turn involves motivations and cognitive limitations in acquiring and processing information, essential to ensure the well-being of current and next generations, approach suggested by the framework in question.

Os manguezais de Bertioga localizam-se próximos ao limite sul de distribuição dessa comunidade vegetal na costa brasileira e no hemisfério sul. Esses bosques são compostos por três espécies: Rhizophora mangle L., Avicennia schaueriana Stapf & Leechman e Laguncularia racemosa Gaertn f. e apresentam estrutura pouco desenvolvida. O manguezal do Rio Iriri possui um diâmetro médio de 8,48 cm, altura média de 6,55 m, densidade de 216 ind/0,1 ha e área basal de 1,29 m2m2/0,1 ha. Já no Rio ltapanhaú, .o diâmetro médio do bosque é de 10,41 em, com altura média de 6,83 m, densidade de 173 ind/0,1 ha e área basal de 1 ,69 m2/0,1 ha. Estimativas de biomassa nos dois locais de estudo resultaram em valores de 42,3 t/ha para o Rio iriri e 59,7 t/ha para o Rio Itapanhaú e a produção anual de madeira foi de 3,6 e 1,9 t/ha respectivamente. Esse baixo desenvolvimento estrutural é provavelmente devido às baixas temperaturas alcançadas no inverno e aos diversos estresses aos quais estão submetidos esses bosques em função das atividades humanas desenvolvidas na região. A produção de serapilheira desses bosques reflete seus baixos índices estruturais, embora trate-se de bosques de franja inundados duas vezes ao dia por marés de mais de 1 m de amplitude. A taxa média anual de produção de serapilheira foi de 5,6 t/ha no Rio lriri e 4,6 no Rio Itapanhaú. Padrões sazonais foram evidentes para os diversos componentes da serapilheira assim como uma sequência temporal das diversas fases fenológicas. As folhas apresentaram maior produção durante o verão. As flores mostraram picos no final dessa estação seguidas de picos de propágulos no outono. A queda de madeira apresentou maiores taxas principalmente nos meses de inverno. Os fatores que controlam essa sazonalidade estão provavelmente associados à temperatura e pluviosidade. Nesses manguezais a renovação desse material é alta, apresentando baixas quantidades de estoque de serapilheira no sedimento, cujos valores variam de 50 a 164 gPS/m2. Essa renovação se dá através da decomposição, que é bastante rápida, com taxas diárias médias de 0,006 para Rhizophora, 0,011 para Laguncularia e 0,015 para Avicennia. Além da diferença entre as espécies, foi observada uma diferença entre as estações e os sítios. As taxas do verão foram significativamente mais altas que as do inverno. Além disso, o Rio Iriri apresentou taxas médias mais elevadas que o Itapanhaú. Embora o processo de decomposição seja intenso nesses manguezais pela existência de condições favoróveis, a maior parte da renovação se dá através da exportação da serapilheira pelo movimento das marés. A partir da elaboração de um modelo ecológico da dinâmica da serapilheira incluindo sua produção, estoque e decomposição, foi possível estimar essa exportação cujos valores estão em torno de 0,7 gPS/m2 por dia com uma exportação acumulada anual de cerca de 2,5 tPS/ha, o que significa que estes manguezais exportam aproximadamente 50 por cento da serapilhelra que produzem. Essa dinâmica da serapilheira influencia também a ciclagem de nutrientes nesse ecossistema. Para compensar a exportação de materiais esses manguezais apresentam retranslocação de nutrientes como o nitrogênio e o fósforo, mecanismo no qual esses elementos são reabsorvidos da folha antes de sua queda. A imobilização, outro mecanismo para conservar nutrientes durante a decomposição, não foi significativa nesse estudo, ocorrendo apenas com nitrogênio em folhas de Laguncularia. Apesar da retranslocação registrada nesses bosques, tanto para o nitrogênio quanto para o fósforo, esses manguezais não se mostraram eficientes no uso de nutrientes, provavelmente, porque estes estejam disponíveis no sedimento em quantidades adequadas. A variação anual da concentração de nutrientes nas folhas da serapilheira mostrou um padrão sazonal com maiores valores no inverno e menores no verão. Já as folhas verdes não apresentam essa sazonalidade tão nítida:o que ocorre, portanto, é uma maior retranslocação durante a época de maior produção de folhas, mantendo os teores desses nutrientes na copa. / The mangroves in Bertioga estuary are mixed forests composed by three species: Rhizophora mangle L., Avicennia schaueriana Stapf & Leechman and Laguncularia racemosa. Gaertn f. Both study sites are frequently flooded by tide waters and can be classified as fringe forests, according to the physiographic types. The Rio Iriri site had a DBH of 8,48 cm, and a mean height of 6,55 m, density in this site was 216 trees/0,1 ha and the basal area was 1,29 m2/0,1 ha. In Rio Itapanhaú, mean DBh was 10,41 cm, with mean height of 6,83 m, density of 173 trees/0,1 ha and basal area of 1,69 m2/0,1 ha. Based on the structural parameters it is possible to see that DBH and tree height of these forests are equivalent to other fringe sites, but density and basal area are much lower. The DBH increment was similar to measurements presented in other studies. However wood production was much lower, because of low density. Biomass estimate of each site forest were: for rio Iriri the biomass was 42.3 t .ha-1 while in rio Itapanhaú it was 59.7 t. ha-1. Mean annual littertall rates were 5.6 t.ha-1 .yr -1 in Rio Iriri and 4.6 t.ha-l.yr-1 in Rio Itapanhaú. However, these forests are fringe mangroves which normally have higher production rates. In this study litter fall production was seasonal with a trend of alternate peaks for the various components which appears to be a sequence within the year. Leaf fall is higher in the summer which is the rainy season (from November through February) followed by the miscellaneous peak in the autumn (from March through May) while the period of higher wood production is from June to October. This pattern suggests a coordination among phenological phases. The factors controlling those variations are still not clearly established. Environmental conditions related to rainfall and temperature are the most probable responsibles for this influence. The decomposition potential of the mangrove sites in Bertioga region (23º51\'5) was high and this might be due to high temperature associated to high rainfall and frequent flooding that create good conditions (hot and humid environment) to accelerate the organic matter degradation. Species showed different decomposition rates. The highest value of k were observed for A. schauerianna (0.015 d-1) followed by L. racemosa (0.011 d-1 ). The lowest value of k occurred in R. mangle (0.006 d-1 ). Brazilian studies of litter decomposition with the same species showed the same gradient of species specific rates. Those differences can be explained by differences in the resource quality. Chemical composition of leaf material is very important in determining its decomposition rate. There was also a significant difference in decomposition rates among species and between sites and seasons. Iriri had higher decomposition rates than Itapanhaú. Summer season had higher decay rates than winter. The processes of decomposition are regulated by the combined effects of the resource quality and the physico-chemical environment on the community of decomposer organisms. According to these main controlling factors, differences observed among species should be attributed to differences in substrate quality, while differences among sites or seasons would be related to different environmental conditions. Seasons differences would be more related to climate features while site differences in this study would be more determined by edaphic features. Although there was an increase in nutrient percentage during decomposition, there was not an increase in their absolute concentration or net accumulation. In Bertioga mangrove forests immobilization was low or absent perhaps because the studied sites are fertiles. In addition, it is only observed in Laguncularia leaves because it is the species with lowest nitrogen concentration what would be a limiting factor. The high content of nitrogen in Rhizophora leaves could be the reason why this nutrient had no net immobilization in this study. Apparently, the absence of phosphorus immobilization could be its availability in both ways, plant tissue and sediment. Mean values of litter standing stock ranged from 50 to 164 g.m-2 throughout the year which are low values, but considering that both are fringe sites it would be expected. Seasonal patterns of litter standing crop can be related to seasonal patterns of litter production, decomposition or hydrological variations. Since in Bertioga decomposition plays a small role because most of litter is removed and hydrology does not show a marked seasonal pattern, litter export and stock reflect the seasonality of litter production and may be a little modified by variations in tidal height. This is not valid for wood component that showed a different behaviour because it is not very influenced by export. Litter turnover rates of this study ( 5.1 and 4.7 yr-1) are higher than other values found in other mangrove forests. The values obtained for leaf fall (14.92 to 24.22 yr-1) in this study are very high even for fringe forest. Analysis of turnover rate for each month indicates that these rates vary throughout the year. especially for leaf fall. The period of higher turnover rates seems to be related to higher litterfall rates, but it may be also an interaction with the variation of tidal amplitude and decomposition. It is possible to see that there is a coincidence of the months of higher turnover rates with the months of higher tidal amplitude. Since measurement of litter export is very difficult because water movements are very complex in a mangrove site and due to the importance of litter dynamics to the tunction of a mangrove ecosystem. the development of a litter dynamics model was useful to understand those processes and organic matter fluxes and to the estimate of export rates. The litter model includes littertall as the input of organic matter, litter standing crop as the storage of organic matter and decomposition and export as outputs of organic matter from the system. Based on these figures it is possible to roughly estimate an annual export of 2,5 t.ha.yr -1. The conclusion is that in these mangrove forests at least 50 per cent of its production is exported by tides. Nutrient content in canopy of mangroves in Bertioga is high and although retranslocation takes place, nutrient concentrations in litterfall are still high. C:N of leaf litter in these forests are low and decomposition should not be nutrient limited. Then litter decay occurs fast with low or none immobilization. These are characteristics of sites with high availability of nutrients. In these forests, although nutrient use efficiency is not very high, nutrient recycling is occurring via retranslocation and not via immobilization during decomposition probably because they are fringe forests. The high retranslocation rates could be a mechanism to prevent loss of nutrients by export. Another important characteristic of these mangroves was the seasonal pattern of nutrient cycling. Nutrient content of leaf fall varies throughout the year with high concentration during winter. Retranslocation also showed a seasonal pattern with higher rates in the summer, resulting in lower nutrient levels in leaf litter and the consequence is a higher nutrient use efficiency in this period of leaf production.

Serviços Ambientais - purificação do ar, estabilização do clima, polinização de culturas, etc. - são funções fundamentais na sustentação da vida humana e têm sua importância econômica cada vez mais evidenciada. Para melhor estudar estes Serviços e saber como eles se comportam, são necessárias novas abordagens para disponibilizar, integrar e compartilhar os dados existentes sobre eles. O projeto ViNCES (Virtual Network Center of Ecosystem Services) propõe a utilização de laboratórios acessíveis via internet - weblabs - com foco em Serviços Ambientais a fim de promover uma melhor compreensão destes serviços. Assim, com o objetivo de viabilizar esta proposta, desenvolveu-se uma arquitetura que permite o acesso aos diversos weblabs do projeto de maneira integrada, disponibilizando os dados de experimentos realizados a um maior número de pesquisadores. A arquitetura proposta fundamenta-se no paradigma de Arquitetura Orientada a Serviços e atende a requisitos de acesso centralizado aos weblabs para a realização e recuperação de experimentos de maneira remota. Esta arquitetura aproveita outras pesquisas na área de Ecoinformática, considerando soluções já existentes no projeto SEEK (Science Environment for Ecological Knowledge). Desta maneira, adota o padrão de metadados EML (Ecological Metadata Language) para a transferência e armazenamento de dados dos experimentos, permitindo que os experimentos fiquem disponíveis a outros pesquisadores que utilizem a infra-estrutura do projeto SEEK. / Ecosystem Services - air purification, climate estabilization, crop pollination, etc. - are essential to sustain human life.Their economic importance is becoming more and more recognized. In order to better study these Services and learn about their behaviour, new approaches are needed for making available, integrating and sharing existing data about them. The ViNCES (Virtual Network Center of Ecosystem Services) project proposes the use of remotely accessible laboratories - weblabs - focused on Ecosystem Services to better understanding these services. In this way, an architecture was developed that allows access to project´s weblabs in an integrated way, giving access to collected data for more researchers. The proposed architecture is based on the SOA (Service Oriented Architecture) paradigm and considers requirements of centralized access to laboratories to, in a remote way, make experiments and retrieve gathered data. This architecture considers other related initiatives in the ecoinformatics field, and uses solutions present in the SEEK (Science Environment for Ecological Knowledge) project. In this way, the EML (Ecological Metadata Language) standard was adopted for transporting and storaging experiments data, and allows that these data are available for other researchers that use the SEEK infra-structure.