Rapid climate change in the Arctic and Sub-Arctic is causing vegetation change across large areas of tundra. Shrubs and trees are undergoing range expansions as part of an over-all trend of ‘greening’ of the tundra. This is of importance because northern peatlands contain around half of total soil carbon (C) and there is a potential for productive vegetation to interact with this C in a number of ways: (1) Ectomycorrhizal fungi (ECM) in symbiosis with trees and shrubs could potentially stimulate decomposition through extracellular enzyme production whilst extracting nitrogen (N) for their hosts; (2) deep snow, trapped by tall vegetation insulates the soil, resulting in higher winter-time microbial activity and has potential to influence growing season microbial activity; (3) the biochemistry of litter and decomposition environment associated with more productive vegetation could result in accelerated mass loss of litter and stimulate decomposition of older soil C. This thesis investigates how productive sub-arctic plant species in Northern Sweden interact with soil C by using ‘space-for-time’ transitions from forests (Betula pubescens), through intermediate shrub vegetation (Betula, Salix), to tundra heath (Empetrum nigrum). This was to test how ECM fungi, winter snow accumulation, defoliation events and litter input influence C cycling. C stocks, respiration rates and ECM growth rates were measured across these ecotones. It was found that birch forests and shrub stands had significantly lower soil C storage and higher respiration rates than adjacent heaths. This is contrary to the predictions of earth system models. Higher ECM growth rates at plots with low C storage and high cycling rates implied that they had an important role in the stimulation of C decomposition. To test whether snow cover in forests over winter had an important effect on C cycling, soils were transplanted between forest and heath (different snow cover), and respiration rates were measured over summer. It was found that deep snow cover over winter increases microbial activity in summer due to a warmer, more stable winter environment; this is hypothesised to be due to the environmental selection of a more active assemblage of decomposing microbes. A defoliation event of part of the birch forest by caterpillars allowed for a natural ‘experiment’. Trees with different degrees of defoliation were compared in their influence over soil C cycling processes. Defoliated plots shifted to slower-cycling states through a shift in the ECM community. This further implied that ECM fungi have an important role to play in rapid cycling of C in forests. A decomposition experiment using the litter of significant plant species in forest, shrub and heath communities was carried out by transplanting them between these key environments. This work showed that rapid decomposition of litter in the forest is driven by an interaction between carbohydrate-rich litter input and an effective decomposer community. This work addresses the relationship between vegetation productivity and C storage in the soil. This theme runs through every experiment as they test specific interactions between different plant groups and the soil. The results from this thesis suggest that increasing productivity and shrub expansion in the Arctic will stimulate decomposition of soil C via a number of pathways. Plant-soil interactions are clearly of importance in determining the fate of C in ecosystems and will play a key part in the balance of C in the future.

Consortium for International Earth Science Information Network (CIESIN) initiated a series of nine human dimensions of global change pilot projects in 1991, to better understand how physical, biological, and social scientists must interact in order to address problems of importance to decision -makers. There is also a need to develop methodologies for merging data sets which differ on spatial and temporal scales, and indeed, to ascertain whether or not data are generally available to address specific, highly complex earth and social science. Because there has been virtually no research on the use of remotely sensed data in the social sciences of global change, this is a component of each pilot project. Pilot projects need to show how the results would be transferred to decision makers. All these elements of the pilots are to be used to inform the design of the CIESIN Data and Research Center. One of the CIESIN human dimensions of global change pilot projects is situated on the north coast of the Dominican Republic in Buen Hombre.

Climate change is one of the greatest threats to marine environments globally. Fisheries are being increasingly affected, with impacts not only to fish stocks but also the fishers who rely on marine resources for their livelihoods. This thesis uses an interdisciplinary, mixed methods approach to examine climate change impacts on fisheries within the under-studied, yet rapidly warming, south-west region of the UK. The thesis begins with a comprehensive review of the literature regarding climate change impacts on UK fisheries, the vulnerability of these fishery systems to future climate change and how climate change is perceived among fishers. In Chapter 2 a methodology is developed to standardise abundance data across multiple scientific fisheries survey datasets in order to facilitate future projections to be generated for the south-west UK region. Chapter 3 presents future projections of abundances and distributions for eight key commercial fish species under future warming scenarios until the end of the century. Results suggest that increasing temperatures and limitations of bathymetry are key drivers of species responses. Certain cold-water species including Atlantic cod (Gadus morhua L.) and anglerfish (Lophius piscatorius L.) will experience declines, while warm-water species such as red mullet (Mullus surmuletus L.) and John dory (Zeus faber L.) are expected to expand across the region. The uncertainty associated with future projections is explored through the use of 11 separate climate-ensembles. Chapter 4 uses information gained through interviews with fishers from a UK fishing port—Brixham—to explore how climate change is perceived and the factors influencing these perceptions. Findings suggest that while fishers generally felt that climate change posed a low risk to the future of their businesses and fisheries in the region, three groups emerged that showed differences in the extent to which they perceived climate change as a risk. A number of key factors were important in influencing these three groups. Chapter 5 develops further insight into fishers’ perceptions by exploring how fishers anticipate climate change to affect the physical environment, fishery resources, and their own practices in the future. Many fishers felt they would not need to alter their fishing practices in the future, with various reasons cited including personal preferences and perceived constraints to their adaptation. Fishers’ ability to adapt was further explored and three main groups were identified who differed according to a number of core dimensions of their adaptive capacity. Through adopting an interdisciplinary approach, the research in this thesis presents a number of new findings that have important implications for fisheries management and climate adaptation policies.

Aquesta tesi vol contribuir a comprendre millor els sistemes socioecològics i el seu canvi al llarg del temps des d’un punt de vista holístic i relacional. Pretén mostrar que les activitats productives del camp no són necessàriament incompatibles amb la conservació de la biodiversitat, i que algunes d’aquestes activitats, fins i tot en situacions d’integració en economies de mercat, són indispensables per conservar els paisatges culturals que les societats urbanes modernes volen protegir. La tesi es pregunta si la recuperació i l’expansió de la superfície forestal poden tenir un efecte negatiu en l’escolament de les conques i el cabal dels cursos d’aigua, així com en la biodiversitat pròpia d’hàbitats oberts a escala local. També explora la transformació del camp durant el procés d’industrialització i urbanització per recolzar la noció d’una interrelació i hibridació històriques entre el rural i l’urbà, i mostra que l’expansió urbana és el resultat d’intenses lluites polítiques entre diferents grups socials amb una distribució desigual dels costos i els beneficis del canvi socioecològic. La Mediterrània és una regió especialment idònia per als objectius d’aquesta recerca, ja que es considera un ‘hotspot’ de biodiversitat mundial el qual és resultat de la integració entre processos naturals i humans. A més, està fortament amenaçada degut a la gran sensibilitat dels seus ecosistemes envers tots els components del canvi global. La tesi se centra en la Regió Metropolitana de Barcelona, a Catalunya, una de les ciutats més grans de l’Europa mediterrània, i específicament en dos municipis de muntanya baixa de la segona corona metropolitana: Olzinelles, al massís del Montnegre, i Matadepera, al massís de Sant Llorenç del Munt i la serra de l’Obac. La metodologia es basa en una combinació d’elements de la història ambiental, l’ecologia política i la hidrologia forestal amb el coneixement ecològic de la pagesia local. L’anàlisi del sistema productiu d’Olzinelles i les seves arrels històriques (capítol 4) mostra com les diverses pràctiques de gestió dels recursos naturals, incrustades en un marc institucional i una cosmovisió particulars, permetien al sistema socioecològic adaptar-se a les variacions de la demanda externa i al mateix temps mantenir la seva capacitat per proporcionar aliments a la població local. L’abandonament d’aquestes pràctiques durant un procés de modernització a escala nacional i global ha comportat una reducció de les poblacions d’espècies pròpies de camps, pastures i boscos esclarissats. A l’escala de conca (vall d’Olzinelles, capítol 3) es conclou que l’assecament de la riera observat en les darreres dècades s’ha d’atribuir a un període més sec i no pas a la petita aforestació que hi ha tingut lloc. No obstant, en futurs estudis caldria incorporar la variació de la coberta arbòria ja que té un rol important en la intercepció i la partició de la pluja, i en les darreres dècades ha experimentat un fort augment com a resultat de l’abandonament de les pràctiques de gestió forestal. L’anàlisi de Matadepera (capítol 5) mostra com en el procés d’expansió urbana s’enfrontaren diferents visions del futur de diferents grups socials (propietaris de terres i pagesia d’esquerres). El projecte socioecològic de les elits dominants va esdevenir una realitat perquè van ser capaces de controlar recursos vitals com la terra i l’aigua amb l’aniquilació de la dissidència a través de la presó, les execució i la violència psicològica del règim franquista sorgit al final de la Guerra Civil (1939). La construcció discursiva d’una ‘escassetat natural’ va ajudar a construir un consens espontani en relació als impactes negatius de l’arribada de grans quantitats d’aigua procedent del riu Llobregat per a possibilitar la gentrificació del poble. La tesi conclou que una combinació adequada de diferents graus d’hibridació socioecològica en l’anàlisi de la realitat pot ser una bona forma d’entendre les dinàmiques complexes dels canvis en els usos de la terra i de la conservació de la biodiversitat en llocs concrets, i també útil per superar l’estricta separació conceptual i analítica entre societat i natura, camp i ciutat, conservació i desenvolupament, i àrees protegides i no protegides. / This thesis is aimed to better understanding the coupled social-ecological systems and their change over time in a holistic and relational way. It intends to show that productive rural activities are not necessarily incompatible with conservation of biodiversity, and that some of these activities, even when they are quite integrated with market economies, are indispensable to conserve the cultural landscapes that modern urban societies want to protect. This thesis also asks whether forest recoveries have a negative effect on water discharge from the catchments and on the biodiversity from open habitats at a local scale. It also explores the transformation of the countryside during the process of industrialization and urbanization to support the notion of historical interrelatedness and hybridity between the rural and the urban; and shows that suburbanization is the outcome of political struggles between different social groups resulting in uneven distribution of the costs and benefits of socioecological change. The Mediterranean is a particularly illuminating region for the aims of this research since it is considered a hotspot of global biodiversity which itself is a consequence of the integration between natural and human processes, besides being highly threatened because of the particular sensitivity of Mediterranean ecosystems to all drivers of global change. This thesis is focused in the Barcelona Metropolitan Region (Catalonia), one of the largest cities of Mediterranean Europe, more specifically in two mountain municipalities of the outer metropolitan ring: Olzinelles, in Montnegre Mountains, and Matadepera, in Sant Llorenç del Munt Mountains. The methodology combines elements from environmental history, political ecology and forest hydrology with the local ecological knowledge from peasants. The analysis of the productive system of Olzinelles and its historical roots (chapter 4) shows that several management practices, embedded in a particular institutional setting and worldview, allowed the social-ecological system to adapt to the changing external demand while keeping its capacity to supply food to the local community. The abandonment of such practices under a national-to-global process of modernization resulted in a decrease of species from fields, meadows and sparse forests. At the catchment scale (Olzinelles valley, chapter 3) it is concluded that the observed decrease in the water runoff may be attributed to a drier period rather than to the small afforestation experienced in the catchment. However, future studies should incorporate the variation of canopy cover given its potential role in rainfall interception and partitioning processes, and the great increase in canopy cover experienced in the catchment as a result of the abandonment of forest management practices. The analysis of Matadepera (chapter 5) shows that different visions of the future by different social groups (landowners vs. left-wing peasantry) collided in the process of suburbanization. The socioecological project promoted by ruling elites prevailed because they were able to control vital resources like land and water with the annihilation of the dissidence through prison, execution and psychological violence under the new Francoist regime that arose after the end of the Civil War in 1939. The discursive construction of a ‘natural scarcity’ of water helped to achieve spontaneous consent for controversial aspects of bringing water from the Llobregat River to allow the gentrification of the town. The thesis concludes that a suitable combination of different degrees of socioecological hybridity in the analysis may be suitable to understand the complex dynamics of land change and biodiversity conservation in a particular setting, as well as useful to overcome the strict conceptual and analytical separation between society and nature; city and countryside; conservation and development; and protected and non-protected areas.

The purpose of this report is to help fisheries officials better understand the cultures of small - scale fishing communities. By doing so they will be better prepared to develop more successful management policies and practices, and to help people in such communities to have more decent lives. The paper discusses cultural characteristics of small-scale fishing communities that are particularly important for fisheries officials to understand. Methods which might help fisheries managers to obtain trustworthy and reliable information about fishing cultures in an ethical manner are also suggested, including methods for rapidly acquiring important information while working within tight budgetary and time constraints. Recommendations appearing near the end of the paper provide guidance concerning how the foregoing objectives can be achieved, underscoring the importance of sustaining small –scale fishers' rights of access to fisheries resources while making their cultures integral considerations in fisheries- management policies and practices. Buen Hombre is one of six case studies of contemporary small -scale fishing communities from distinct world -culture regions are annexed at the end, richly exemplifying many of the issues discussed in this report The essay written by Richard Stoffle is about the people of Buen Hombre, a small coastal fishing and farming village of about a thousand people located on the north coast of the Dominican Republic near the Haitian border. It is found on pages 219 – 245. The people of this village deal with the normal and abnormal problems of change. These changes are sometimes global and sometimes local. Changes occur in their climate, economy, and their environment. The people of this village prepare for and accommodate to these changes by (1) promoting a conservation ethic and (2) limiting access to their marine resources. When they are successful, fish -based food security issues are ameliorated. This essay discusses food security issues as these were faced by the people of the village of Buen Hombre from 1985 to 1995. While this is a very small segment of time, many changes did occur and these illustrate key temporal and spatial processes. Short-term changes in the economy and climate are common for coastal peoples who must constantly adjust their adaptive strategies to survive. The full reference for the entire report is: McGoodwin, James, R. (2001). Understanding the Cultures of Fishing Communities: A Key to Fisheries Management and Food Security. Rome, Italy: Food and Agricultural Organization of the United Nations; FAO Fisheries Technical Paper 401.

In the last few decades, we have been witness to unprecedented changes in precipitation and temperature. Such alterations to our climate system have important implications for terrestrial ecosystems that billions of people depend on for their livelihood. The situation is especially tenuous for those living directly off the landscape via resources from natural ecosystems or subsistence agriculture as in much of tropical Africa. Studies of past climates provide potential analogues and help validate models essential for elucidating mechanisms that link changes in climate mean and variability and how they may affect ecosystem distribution and productivity. However, despite the importance of the paleo-record for insight into the future, tropical proxy records are rare, low resolution, and too short to capture important intervals that may act as analogs, such as the Last Interglacial (MIS 5e; ~130-115ka).Long, high-resolution drill cores from Lake Malawi, southeast Africa, provide a record of tropical climate and vegetation that extends back ~1.2mya, comprising many continuous glacial-interglacial cycles. My primary research involves conducting pollen analyses on these cores. First, I analyzed a high-resolution interval of the shortest Malawi core in order to better understand abrupt vegetation transitions during the Last Deglaciation. Further analysis was conducted on the longest Malawi core, beginning with an interval covering all of the Penultimate Glacial through the Last Interglacial. The resultant pollen data has shown that abrupt, large-scale landscape transitions from forest to desert follow local insolation and lake levels at the site, with a strong dependence of forest/woodland vegetation types on mean rainfall as well as rainfall seasonality. The interpretation of paleodata requires a good understanding of modern processes, thus another project has focused on using model simulations of the Last Interglacial and modern satellite NDVI time series to highlight dynamical and statistical relationships between vegetation and climate change. This work suggests that despite suggested links between monsoon intensity and SSTs in the southern African tropics, insolation controls on atmospheric circulation are the primary drivers of vegetation reorganization. In addition, this work highlights the importance of rainfall seasonality and dry season length in addition to precipitation controls on vegetation.

Dendrochronology focuses on the relationship between a tree's growth and its environment and thus investigates interdisciplinary questions related to archaeology, climate, ecology, and global climate change. In this study, I examine the growth of two forms of bristlecone pine (Pinus longaeva): strip-bark and whole-bark trees from two subalpine adjacent sites: Patriarch Grove and Sheep Mountain in the White Mountains of California. Classical tree-ring width analysis is utilized to test a hypothesis related to a proposed effect of the strip-bark formation on trees' utilization of atmospheric carbon dioxide. This effect has grown to be controversial because of the dual effect of temperature and carbon dioxide on trees' growth. The proposed effect is hypothesized to have accelerated growth since 1850 that produced wider rings, and the relation of the latter topic to anthropogenic activities and climate change. An interdisciplinary approach is taken by answering a question that relates temperature inferences and precipitation reconstructions from the chronologies developed in the study and other chronologies to Native Americans subsistence settlements and alpine villages in the White Mountains. Strip-bark trees do exhibit an enhanced growth that varies between sites. Strip-bark trees grow faster than whole-bark trees, however, accelerated growth is also evident in whole-bark trees but to a lesser degree. No evidence can be provided on the cause of the accelerated growth from the methods used. In the archaeological study, 88% of the calibrated radiocarbon dates from the alpine villages of the White Mountains cluster around above average precipitation, while no straightforward relationship can be established with temperature variations. These results confirm that water is the essence of life in the desert.

No description available.

Anthropogenic global change is altering food web dynamics. Global change comprises factors, like temperature, sound, light and more. In this dissertation, I evaluate how two factors, sound and temperature, alter prairie communities. In Chapter 1, I test if sound influences grasshopper respiration rate, thereby altering diet. Some sound frequencies increased grasshopper respiration rate while others decreased respiration rate. Frequencies that elevated respiration rate led to grasshoppers consuming more carbohydrate-rich foods compared to protein-rich foods. This diet change stems from a carbon deficit due to increased respiration rate and could act as a mechanism by which sound pollution indirectly alters plant communities. In Chapter 2, I test the hypothesis that sound can alter grasshopper movement. In response to sound-induced stress grasshoppers may alter their movement in one of two ways: in situ and displacement. I found no evidence that grasshoppers, nor non-Orthopteran insects alter their movement in the presence of sound. This chapter provides foundational methods to evaluate sound for applications in conservation and management. Further research will improve techniques for grassland or agricultural systems. Temperature is another driver of community change. What is less understood is how warming influences predator-pollinator relationships. In Chapter 3, I ask if warming alters a spider that consumes pollinators in a prairie system. My results indicate that pollinators benefit when spiders are not on the flower. Warming shifts spiders down the plant, thus positively impacting pollinator-plant interactions. In addition, warming may benefit plants two-fold if spiders shift their diet to herbivores. This requires additional research, but it is evident that warming generates a positive indirect effect on plants. These chapters contribute to a growing understanding of how global change is restructuring ecosystems. While global change may alter population dynamics or lead to evolutionary change over longer time scales, behavioral responses happen rapidly and can drive ecological dynamics in the short term. My dissertation demonstrates that sound and temperature alter animal behavior that cascades to lower trophic levels. Thus, in addition to demonstrating the indirect effects of global change, these experiments contribute to growing literature on the importance of top-down control in shaping ecosystems.

Through the last 60 million years (Ma) there were well-documented climate and habitat changes across North America. Continental and regional scale studies on ungulate (hooved mammals) tooth crown heights in relation to climate and habitat changes have documented an increase in tooth height as environments became more arid to combat a highly abrasive diet of fibrous plants and grit. Based on the relationships between crown height and climate, several studies have used taxon free methods to estimate past precipitation from fossil ungulates. Small mammals have also been shown to adapt to changing habitats, with specializations for life in open habitats appearing millions of years earlier than larger mammals. Utilizing taxon free methods, this study compared the crown heights of rodents and lagomorphs (rabbits and pika) from across North America to climate variables, including both temperature and precipitation. Studying small mammals allows examination of local changes to climate and can be informative of what is to be expected in regional communities if modern warming trends continue. Using ArcMap, modern climate data and mammal faunal lists for 100 random points were compiled and generated across North America. Crown heights of species were categorized and mean crown height for the community was calculated for each site. Linear regressions were used to examine the relationship between crown height and climate variables. Using ArcMap and ordinary kriging, maps were generated of predicted climate for all of North America and compared to known climate data. In general, the North-South gradient of temperature and the Northwest to Southeast gradient of precipitation was captured in predicted maps showing agreement with known climate maps. Regressions were also used to predict climate for 72 well-known fossil sites from the late Eocene (~37 Ma) to Pleistocene (~1.9 Ma) of North America, generating estimates of temperature and precipitation for many sites with no prior climate estimates. Results show strong correlation between rodent and lagomorph crown heights and temperature and precipitation variables. Temperature variables were more strongly correlated to tooth crown heights than precipitation. Overall, a decrease in precipitation and temperature was found across North America from 37 Ma to the present, consistent with prior paleoclimate records from other regional and global proxies. Application to detailed regional records from the Mid Miocene Climatic Optimum (around 15 Ma, during the early Barstovian land mammal age), which was a pronounced period of warming comparable to the warming we see today, showed regional variation in responses to warming. Tooth crown height increased in California and Nebraska before Oregon, showing climate did not change uniformly across North America similarly to what would be expected in modern warming. Using the method proposed in this study, past and future regional climate trends, as well as biotic responses to those changing climate trends can be better understood.