Energy flow and accumulation in the aboveground parts of an alder-birch woodland in County Durham were studied between April 1966 and April 1968, Dry matter transfers and accumulations were measured and converted to energetic data by the use of calorific equivalents. It was shown that only calorific values appropriate to a particular category of material and season provide adequate calorific equivalents.

The Mexican state of Quintana Roo is home to a complex ecosystem. Beneath the state’s surface is a riddle of flooded caves which form part of the world’s most extensive aquifer, above the surface is a vast tropical dry forest, while along the coast line there is one of the world’s longest coral reefs. These systems are directly linked by dispersed water sinkholes, known as cenotes, which pierce through the surface of the land and ocean floor. The state is also home to some of the fastest growing urban centres in the world, driven by mass tourism, the state’s main economic activity. The intersection of these different complex processes and landscape has the focus of this thesis. In particular the research is interested in the appropriation of cenotes, how humans have related towards the underground systems, making use of them, controlling them, enclosing them and transforming them. The thesis draws upon the theoretical notion that commodifying nature has being a determinant way of how humans relate with nature. However these relations are ultimately shaped in different ways, according to each individual’s position and function in the social system. Cenotes, for humans, have been and still are places to perform sacred and religious rituals, places to hide, places to deposit material goods, places to study, places to explore and places to be regulated. This thesis unpacks these relations, critically examining the main drivers of different socio-environmental outcomes in this underground forest frontier.

No description available.

No description available.

Fannich Forest consists geologically of a complex of Moinian and Lewisian rocks. The area was mapped, and from the field-evidence a stratigraphy and structural interpretation were worked out. The structural interpretation was fitted into a regional interpretation of Moinian structure in Western and Central Ross. The petrology of the different rock-types was studied and used to assess the metamorphic grade of the area, while geochemical evidence strongly suggested that a Lewisian Inlier is present in Fannich. Mapping showed that the Lewisian inlier extends south of Loch Fannich on Beinn nan Ramh and on Moine Mor. Complex early folding caused these units to form a repetitive succession deformed by the readily visible structures in the area. Three fold-events have occurred: F₁ folding initiated the formation of an isoclinal anticline with a Lewisian core, and a complementary isoclinal syncline, exposed at present with Sgurr Mor Pelite in its core. F₂ folds refold the Lewisian of Fannich in near-isoclinal folds, and a larger F₂ fold may refold the main F₁ anticline so that it now closes east. F₃ folds, with axial traces broadly trending north-south, are asymmetrical open folds, deforming the foliation developed in the rock during the previous fold-events. They deform an apparent succession in which the Lewisian core of the F₁ anticline forms the second-highest unit. The most important of these folds is the Fannich Synform. Since the Sgurr Mor Pelite occurs in the core of an F₁ syncline, open to the east, the Lewisian of Fannich is separated from the Lewisian of the Central Ross-shire Inliers. It is considered to form part of the upper limb of the refolded Moine (=Morar) Nappe, and to underlie the postulated Central Ross-shire Nappe. It is admitted that sliding may have occurred in Fannich, but the available evidence in Fannich does not require such a slide in order to explain the regional structure. Petrological studies reveal differences in mineralogy and texture between Lewisian and Moinian amphibolites; differences also occur between different amphibolite groups within the Moinian, which are considered to originate from different magmas. In calo-silicate strips from the Sgurr Mor Pelite, a reaction in which biotite forms from hornblende was observed, often accompanied by a reaction forming zoisite at the expense of plagioclase. It was found to be directly influenced by the CaO/Al₂O₃ ratio of the rock. The different ratios at which this reaction proceeded in different places are considered to indicate differences of metamorphic grade. The reaction is retrogressive; the apparent increase of grade with increasing altitude is more probably a result of lessening influence of second, retrogressive metamorphism with increasing height, thus allowing the original (higher-grade) mineralogy to be preserved more fully. Breakdown of kyanite in politic schist, and the accretion of calcic rims around almandines, were also interpreted as signs of retrogression. Electron probe microanalysis of almandines from pelite suggested that much of western Fannich may have been subjected to sillimanite-grade metamorphic conditions, and that the subsequent milder metamorphic episode induced retrogression. By analogy with Morar, places where the hornblende-biotite reaction in calc-silicates occurs at a CaO/Al₂O₃, ratio of 0.4, are approximately on the kyanite isograd. The metamorphic grade now preserved in Fannich is of almandine grade in the north and east, and mainly kyanite grade in the south-west and centre. The earlier metamorphic episode reached maximum intensity about the time of F₂ folding, while the milder late event probably accompanied F₃ deformation. In this respect, as in others, the structural and metamorphic history of Fannich is comparable to that of other Moinian areas. Geochemical evidence reveals differences between Moinian and Lewisian rocks that are not eliminated by metamorphism. Silicic gneisses and amphibolites from the Lewisian rocks contain FeO/TiO₂, K/Rb ratios and zirconium contents different from those of the Moinian, but often resembling those of rocks from the Lewisian Foreland, west of the Moine Thrust. Alteration of these ratios and Increase in zirconium content during sedimentation accounts adequately for the overall persistent differences in composition between Moinian and Lewisian rocks. The very high FeO/TiO₂ ratio of the Lewisian rocks suggests that they may be Scourian, rather than Laxfordian gneisses. Increase in K₂O content and decrease in the FeO/TiO₂ ratio observed in the Lewisian near the junction with the Moinian is tentatively attributed to the effects of weathering of the Lewisian before the deposition of the Moinian. Some K₂O enrichment of the Lewisian may also have occurred during metamorphism, resulting in the secondary growth of biotite in the amphibolites, but little other evidence of metasomatism was seen. Therefore the present chemical composition of the Moinian rock-units is considered to be broadly that of the original sediments. Chemical evidence was used to confirm petrological evidence that Lewisian rocks occur in Fannich, both where previously mapped, and south of Loch Fannich, and the interpretations of the structure are based on this conclusion.

Wet woodlands have been recognised as a priority habitat and have featured in the UK BAP since 1994. Although this has been acknowledged in a number of UK policies and guidelines, there is little information relating to their detailed ecology and management. This research, focusing on lowland Alnus glutinosa woodlands, aimed to address this data paucity through the analysis of species requirements and to develop a methodology to guide appropriate management for this habitat for the benefit of wildlife. To achieve these aims data were collected from 64 lowland Alnus glutinosa woodlands and a review of the literature was undertaken to identify species associated with the target habitat. The groundflora species found to be associated with lowland Alnus glutinosa woodland were assessed in relation to their optimal environmental conditions (Ellenberg indicator values) and survival strategies (Grime CSR-Strategy) to determine the characteristics (Characters of a Habitat; CoaHs) and range of intra-site conditions (Niches of a Habitat; NoaH). The methodologies, using CSR and Ellenberg indicator values in combination, were developed to determine NoaHs and were tested both quantitatively and qualitatively at different lowland Alnus glutinosa sites. The existence of CoaHs and NoaHs in actual sites was verified by detailed quadrat data gathered at three Alnus glutinosa woodlands at Stonebridge Meadows, Warwickshire, UK and analysed using TWINSPAN and DCA ordination. The CoaHs and NoaHs and their component species were confirmed to have the potential to occur in a particular woodland. Following a literature search relating to the management of small wet woodlands within the UK, in conjunction with the current research, broad principles and strategies were identified for the management of lowland Alnus glutinosa woodland. Using the groundflora composition, an innovative procedure is developed and described for identifying the potential variation within a particular site and determining its appropriate management. Case studies were undertaken on distinct woodlands and the methodology proved effective.

No description available.

No description available.

Natural ecosystems like forests, wetlands and coastal habitats are hypothesized to support disaster risk reduction by decreasing the exposure of communities to hazards such as floods, landslides and storm surge. Forest cover loss is thought to increase flood risk and is seen as a primary driver of soil erosion and consequent siltation of irrigation channels and agricultural fields. While there is a growing body of evidence in support of the role of ecosystem processes in providing these hazard mitigation services much of it is site specific, and gaps remain in our understanding of the specific contexts, type of hazards and scenarios in which forest ecosystems play this role. This study contributes new knowledge to this research gap by investigating the question of how smallholder farmers in Madagascar exposed to extreme weather hazards perceive the importance of tropical dry deciduous forests in regulating hazard impacts and supporting agricultural production. In doing so, this thesis first evaluates the evolving trajectories of change in system variables including various provisioning ecosystem services, biophysical, economic and governance indicators, and human wellbeing outcomes during Madagascar’s recent history to provide context and identify patterns at the national scale. It then investigates the problem at the local, sub-catchment scale in a case study setting through household surveys, focus groups and key informant interviews in two communities with opposing forest cover trajectories in northwest Madagascar. This combined methodological approach allows for the linking of local vulnerability to wider system dynamics. The first set of findings demonstrates that the broader systems dynamics show signs of trade-off between increasing crop production, deteriorating natural environment and decreasing human wellbeing, which together with an evident decrease in the level of connectivity between key parameters reflect conditions associated with stagnation and poverty traps. Case study results show a vulnerable smallholder farming population, typically exposed to a set of six hazard impact types during extreme weather events. The type of hazards experienced influences the perception of whether or not forests provide hazard impact mitigation benefits and this is one of thesis’ original contributions to knowledge. Another core finding confirms the importance of tropical dry forests to the lives of smallholder farmers through food and raw materials, and provides new insights on the positive view held by a majority of the participants of hazard mitigation services provided by forest fragments, while also finding that only the income generating services of forest based tourism and honey production predict participation in forest management. This study integrates two normally distinct areas of research – hazard mitigation and forest ecosystem services - to provide new insights on the relevance of forest cover and management to agricultural risk reduction in smallholder, forest-edge farm communities, contributing new knowledge with implications for both forest management and rural development policies.

Tropical species are facing multiple environmental pressures, whereby agricultural expansion is causing rainforest loss and climate warming is resulting in range shifts to higher elevations. In Southeast Asia, biodiversity is severely threatened by oil palm expansion and much of the remaining lowland rainforest persists within isolated fragments and protected areas (PAs). I assessed the permeability of oil palm plantations to forest dependent species by examining boundary crossing abilities of fruit-feeding butterflies. I showed that crossing was dominated by species that could potentially breed within oil palm plantations, suggesting that plantations may act as dispersal barriers to forest species. Using the PA network on Borneo as a model system, I examined the spatial distribution of climate within PAs in future, and examined the connectedness of PAs along elevation gradients. For the majority (~60-90%) of PAs, which were predominantly situated at low elevation, analogous climates in future will only be available at higher elevation, requiring species to move in order to track cooler climates. However, over half (~60-82%) of these PAs were too isolated for species with poor dispersal abilities to reach cooler, higher elevation PAs. Finally, I used a novel modelling approach based on electrical circuit theory to identify important areas of rainforest connecting PAs along elevation gradients, and showed considerable spatial overlap in expansion routes under contrasting projections of warming. Protected area extent on Borneo will need to increase by approximately one fifth (~17%) to conserve all important rainforest connections between PAs. I conclude that rainforest species may be particularly vulnerable to the impacts of continued agricultural expansion and climate change, as they may be unable to move across fragmented landscapes due to lack of connecting rainforest habitat. Management to improve linkage of PAs and ensure protection of important dispersal routes along elevation gradients should be a conservation priority.