Agricultural expansion is driving tropical deforestation and the conversion of fertile floodplains along large meandering rivers. Yet despite a wealth of research showing the importance of riparian vegetation to the processes of riverbank retreat, little is known of the geomorphic response of large rivers to the rapid removal of natural riparian cover. The Kinabatangan River in Northern Borneo offers an important opportunity to study the morphological change induced by extensive land conversion, as palm oil plantations have replaced much of the floodplain forest in recent decades. Using LANDSAT imagery from 1989 – 2014 I examine the impact of widespread land use change on the meandering dynamics of the Kinabatangan River, and quantify the provision of an ecosystem service by riparian reserves to adjacent oil palm plantations. Rates of channel migration following deforestation increase by >23%, and the correlation between planform curvature and rates of riverbank retreat only became strongly positive and significant after the removal of natural riparian cover, suggesting an important role of forests in the evolution of meandering rivers, even when riverbank heights exceed the depth of root penetration. By means of a numerical model of channel migration that explicitly represents the role of a dense root network in controlling the residency time of slump blocks, I then demonstrate that riparian vegetation can affect rates and patterns of channel migration by altering the composition and fate of failed bank material armouring the bank toe. Furthermore, I estimate the value of the geomorphic ecosystem service that riparian reserves provide by protecting adjacent oil palm plantations from bank erosion over long-term economic horizons.

The addition of composted greenwaste (CGW) into soil-forming materials during land reclamation may improve tree growth, alleviate certain negative soil properties and provide an effective waste management solution. CGW addition may also assist the establishment of sustainable earthworm populations, which in turn can further aid soil development through their burrowing and feeding activities. Despite these potentially mutual benefits, little research exists into CGW and earthworm interactions with trees on reclaimed land, and the aim of this thesis was to investigate such interactions. A large-scale field experiment and a nursery-based mesocosm experiment revealed the responses of the tree species Italian alder (Alnus cordata) and Norway maple (Acer platanoides) to CGW and earthworm addition in reclaimed soil. Findings revealed a synergistic effect of CGW addition and earthworm activity leading to significantly greater A. cordata and A. platanoides growth. CGW addition significantly increased levels of soil organic carbon and essential plant macro-nutrients, with earthworm activity increasing the accumulation of organic carbon into reclaimed soils. Additional laboratory-based research revealed the performance of four common UK earthworm species in reclaimed soil, and demonstrated that CGW can support earthworm establishment, and that the earthworms Aporrectodea longa and Allolobophora chlorotica are particularly suitable candidates for inoculation to reclaimed soil. These two earthworm species showed a preference for the foliar material of A. cordata over A. platanoides, but after two weeks, microbial degradation of leaf litter increased A. platanoides leaf palatability to these earthworms. These two tree species may therefore be capable of supporting earthworm populations on reclaimed landfill. A survey of a newly reclaimed site showed that natural colonisation of reclaimed land by earthworms can occur rapidly (within 2 years), where soil quality is sufficient and legacy soil materials are stockpiled and applied following best practice guidance. The studies in this thesis demonstrate methods for effectively improving woodland establishment and soil quality on reclaimed landfill, through CGW application and earthworm activity promoting soil development and encouraging tree growth.

Arboreal travel for large apes is energetically demanding and risky due to the complexity of the forest canopy. Careful selection of supports is therefore essential for safe and efficient locomotion. This thesis investigates the factors involved in route and support selection in bonobos (Pan paniscus) and in modern human (Homo sapiens) tree climbers. Naturalistically housed bonobos were given a choice of two ropes, one that provided easy access and another that required more demanding postures, with which to access a hard-to-reach food goal. The bonobos selected a rope based on its distance from the goal and its flexibility. Decision making in human tree climbers was investigated using a novel combination of qualitative (participant interviews) and quantitative (observations of behaviour) data. Participants were asked to collect goals from within a tree crown three times each. Interviews revealed that participants either considered risk avoidance or ease/efficiency as the main factor influencing their decisions whilst climbing. Those considering risk took longer to complete each climb, but became quicker after their first climb. These studies demonstrate that the demands of the arboreal environment require knowledge of the functional properties of supports and that memory of specific routes may increase the efficiency of arboreal locomotion.

No description available.

Tropical forests have been studied by community ecologists since the earliest days of the field because of their diversity and complexity and much of the theory behind community assembly has been developed in the tropics. However, the processes that act to assemble species in tropical forest across a very fine scale are still poorly understood. This study investigates community structure in 20ha area of hyper diverse tropical rainforest in Sabah, Malaysia. In order to examine community phylogenetic structure, I reconstructed a molecular phylogeny for all species in the study site using DNA barcoding loci. From this, I calculated phylogenetic diversity metrics for each community and then used a null model to compare observed phylogenetic diversity with that which would be expected if communities were randomly assembled with respect to phylogeny. The analyses showed that communities are more closely related than predicted by the null model. I also collected species functional trait data and showed that species assemblages and community weighted mean trait values correlate with environmental gradients on the plot. I also compared functional diversity to data simulated from null models. This showed that communities are on average more functionally similar than predicted at random. Finally, I performed a multivariate analysis with environmental, spatial, phylogenetic and trait data from communities across the plot. The analyses recovered an elevational and soil gradient that correlated strongly with community composition. Species occupying different ranges along this gradient had differing trait values and were phylogenetically distinct. These analyses demonstrate that even fine scale environmental variation is influential in assembling communities over a small area of forest. A soil nutrient gradient is consistently recovered that correlates with topography, suggesting that soil nutrient distribution is mediated by the downslope movement of water leaching soils on ridge tops and leading to accumulation of nutrients in valleys. This gradient is associated with species compositional variation and also with community weighted mean functional traits, indicating that the environment is influencing species distributions even over very small areas. Communities were both functionally and phylogenetically clustered, adding further support to this conclusion.

This PhD thesis seeks to consider conifer forestry stream corridor design in relation to both in-stream and riparian zone biodiversity and functioning. The contribution, availability and source of basal resources within varying corridor conditions are the focus of this project. This approach is combined with surveys of community diversity on a number of key trophic scales in order to determine how the corridor characteristics and their associated resource availability, affects community structure. The effects of varying design and management of the riparian buffer zones within afforested stream systems on in-stream and overall habitat diversity and functioning remains largely unknown. Although guidelines have been implemented for several years (Forest and Water Guidelines, Forestry Commission), recommendations, although based on sound assumptions, are subjective assessments and tend not based on scientific research or data. As such, the premise of this project is to consider a variety of corridor physical parameters adjacent to low-order streams within two afforested catchments in South-West Scotland, between 2003 and 2005, in order to contribute to the understanding of system functioning within the limitations of forestry land-use and management. A number of different approaches were employed in order to define the proportional contributions of allochthonous and autochthonous material within the benthos of the stream systems. This was done in order to define resource availability, biofilm characteristics, stream functioning and the role of corridor design in influencing resource availability. Yet, despite significant autochthonous productivity, allochthonous organic matter was the primary resource utilised by many taxa. However, conversely, light regime was found to be fundamental in shaping production and community structure within these ecosystems. Consequently, here I explore a number of different trophic scale responses to riparian conditions in order to define the biotic responses to variation of resource availability, with the aim of contributing information which may aid in design and management of afforested riparian zones.

This thesis quantifies aspects of shade tolerance in tree seedlings of species native to the Caledonian pinewood ecosystems of Glen Affric (Highland Region, Inverness-shire). Growth, allocation and morphological responses of 15 species to irradiance under simulated forest canopy light were investigated in a nursery-based shade house experiment. The same responses of four of the 15 species (Ilex aquifolium, Alnus glutinosa, Sorbus aucuparia and Betula pubescens) to different developmental stages of Pinus sylvestris woodland were investigated in the field. The spatial and temporal growth responses of naturally regenerating S. aucuparia seedlings to shade and gap microhabitats were also studied. Data from the shade house experiment enabled further detailed exploration of the relationship between relative growth rates (RGR) and irradiance and potential cross-overs of ranks of growth in high and low light conditions.

No description available.

This study investigates the variation in the spatial patterns of Diptera and Collembola throughout the forest canopy due to seasonal changes in temperature and humidity in the monsoon climate of West Africa. There is a very distinct turnover in climate from the end of the dry season (the hottest and driest time of the year) to the beginning of the rains and this coincides with significant increases and decreases in the overall abundance of many forest dwelling Diptera and Collembola species. The study investigates spatial patterns on two gradients; vertically from the ground to the high canopy and laterally from the edge of the forest to the core, with the added complexity of the affects of anthropogenic burning of adjacent savannah. The results show that seasonality and the starting of the rains significantly affect both the overall abundance and the spatial patterns, providing species with a strategic change in habitat niche. During seasonal conditions that are less conducive to species' overall abundance, spatial patterns are suppressed by environmental conditions. However when environmental conditions are optimum for increased species abundance, spatial patterns are only suppressed by the availability of resources within the habitat (feeding or reproductive resources for example). Successive late burning events may have changed the structure of the forest edge introducing a significantly more open forest structure changing environmental conditions and thus creating a habitat more suitable for species which prefer lower humidity and higher temperatures.

The project sought to identify direct links between calculate hillslope solute fluxes and input/output budgets in a forested drainage basin in the United Kingdom. An intensive, short term monitoring and data collection programme was devised in order to quantify the major components for the hillslope hydrological cycle, the seasonal changes in overstorey and understorey biomass, and the chemical composition of ecologically and pedologically derived samples. Gross and net precipitation, infiltration, and soil moisture fluxes, groundwater movement and streamflow were monitored to identify the possible pathways which solutes might follow. Regular sampling of the oak and bracken vegetation, litterfall and litter enabled calculation of biomass accumulation and the rate of uptake and release of plant nutrients. The spatial variability of soil properties was quantified, but subsequent soil sampling permitted identification of seasonal trends in exchangeable action and soil water solute concentrations. All hydrological and ecological samples were analysed for nitrogen, phosphorus, potassium, calcium, magnesium, sodium and chloride. PH, specific conductance and organic carbon were measured for selected samples. The high infiltration capacity of the soil promoted rapid vertical movement of water towards a perched water table. The presence of soil macropores and the high permeability of the soil precluded the generation of throughflow on the hills-lope. Stream discharge was mainly controlled by groundwater fluxes from the perched water table. Although seasonal trends in the solute concentration of water samples and in the nutrient assimilation of vegetation were identified, isolated events, such as frassfall and storm-period litterfall, were shown to contribute significant quantities of nutrients to the forest floor, The importance of solute movement via macropores, especially phosphorus, was emphasised, with particular reference to plant availability. The relative stability of the ecosystem was reflected in the balance of the input/output budgets of solutes, with, the exception of calcium and magnesium losses which were attributable to weathering of the calcareous bedrock. Bivariate and multivariate statistical analysis showed that no single biogeochemical process on the hillslope could be identified as exerting a dominant controlling influence on stream water chenistry, through isolated events may affect concentrations in the short term.