Mapping topography and broad vegetation type to characterise the Boxford meadows SSSI (Unit 2)

Understanding the dynamic relationship between hydrology and ecology in a complex wetland setting should be considered integral to the sustainable management and conservation of wetland habitats and future water resource planning. Wetland hydrology can exhibit considerable spatial complexity as a result of sub surface and surface heterogeneity. The latter of which may be determined by the relationship between spatial topography variation and broad vegetation distribution. Any study to investigate such a relationship must be at a spatial resolution sufficient to identify patterns in surface topography and vegetation type. In this study state of the art survey technology was used to collect and record for subsequent mapping the topographic and vegetation characteristics of the Boxford lowland chalk groundwater dependent terrestrial ecosystem (GDTE). The resultant survey dataset successfully unveiled distinct patterns in topography and vegetation type. The analysis of the data in a Geographical Information System (GIS) desk confirmed for the first time the presence of paleo-channels and a braided fluvial system within the meadows. In addition the combined survey method gives some indication that the type of vegetation present appears to coincide with some of the more distinctive topographical features. The results demonstrate that combining the field survey campaign alongside desk based GIS analysis is an extremely useful and versatile tool and can provide valuable information to support the decision making process for both further scientific investigation and sustainable habitat management

Diagnostic monitoring of a changing environment: An alternative UK perspective

Adaptive management of the marine environment requires an understanding of the complex interactions within it. Establishing levels of natural variability within and between marine ecosystems is a necessary prerequisite to this process and requires a monitoring programme which takes account of the issues of time, space and scale. In this paper, we argue that an ecosystem approach to managing the marine environment should take direct account of climate change indicators at a regional level if it is to cope with the unprecedented change expected as a result of human impacts on the earth climate system. We discuss the purpose of environmental monitoring and the importance of maintaining long-term time series. Recommendations are made on the use of these data in conjunction with modern extrapolation and integration tools (e.g. ecosystem models, remote sensing) to provide a diagnostic approach to the management of marine ecosystems, based on adaptive indicators and dynamic baselines

Resonances in 19Ne with relevance to the astrophysically important 18F(p,α\alpha)15O reaction

International audienceThe main source of gamma ray emission from novae below 511 keV is likely to be associated with the beta+ decay of 18F. The main uncertainty in the abundance of this nucleus comes from the 18F(p,alpha)15O reaction. In 2006, through microscopic techniques, two previously unseen energy levels in the compound 19Ne nucleus, at 6 and 7.9 MeV were proposed by Dufour and Descouvemont. In light of this there have been two published attempts in the search for the higher of these states, by Murphy et al. and Dalouzy et al.. The aim of this work is to address the contradiction between these works and come to a conclusion as to the possible existence of this state. An experiment has taken place that utilised a 4 MeV/u 18F beam, degraded to 1.9 MeV/u, incident upon a thick CH2 target. The data has been analysed within the R-matrix formalism and preliminary results are presented here

Territorial behaviour and population dynamics in red grouse Lagopus lagopus scoticus. I. Population experiments

<p>1: According to the ‘territorial behaviour’ hypothesis, population cycles of red grouse are caused by delayed density-dependent changes in the aggressiveness of territorial cocks. We report here on a replicated population experiment testing assumptions of this hypothesis.</p> <p>2: We used testosterone implants to increase aggressiveness of cocks for 3 months during autumn, when recruitment and territory establishment take place. On two moors located in northern England, and on two 1-km2 areas within each moor, we implanted adult cocks with testosterone on an experimental area and with sham implants on a control area.</p> <p>3: During the first autumn, the testosterone treatment prevented recruitment of young cocks into the territorial populations. This reduced breeding density and altered the age ratio among territorial cocks, and possibly levels of kinship. If so, the ‘kinship’ hypothesis predicted that density and recruitment should continue to differ between testosterone-treated and control areas.</p> <p>4: Grouse density remained significantly lower on the experimental than on the control areas for two consecutive breeding seasons. This confirmed a strong spatial structuring within grouse populations, which prevented immigration from neighbouring higher-density areas. In the second autumn, testosterone was not implanted but the recruitment rate remained significantly lower and cock density continued to decline more on the experimental than on the control areas.</p> <p>5: The results suggest that cocks continued to be aggressive and to maintain large territories for at least a year after aggressiveness was increased experimentally, and therefore that autumn aggressiveness is influenced by previous territorial contests.</p> <p>6: The experiment validates key assumptions of the ‘territorial behaviour’ hypothesis for red grouse cycles. Population models in a subsequent paper demonstrate how changes in aggressiveness can cause population cycles.</p&gt

Resonances in 19Ne with relevance to the astrophysically important 18F(p,α)15O reaction

The main source of gamma ray emission from novae below 511 keV is likely to be associated with the β+ decay of 18F. The main uncertainty in the abundance of this nucleus comes from the 18F(p,α)15O reaction. In 2006, through microscopic techniques, two previously unseen energy levels in the compound 19Ne nucleus, at 6 and 7.9 MeV were proposed by Dufour and Descouvemont. In light of this there have been two published attempts in the search for the higher of these states, by Murphy et al. and Dalouzy et al. The aim of this work is to address the contradiction between these works and come to a conclusion as to the possible existence of this state. An experiment has taken place that utilised a 4 MeV/u 18F beam, degraded to ∼1.9 MeV/u, incident upon a thick CH2 target. The data has been analysed within the R-matrix formalism and preliminary results are presented here.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

Territorial behaviour and population dynamics in red grouse Lagopus lagopus scoticus: II. Population models

<p>1. Recent experiments on cyclic red grouse populations discovered that aggressiveness, induced by testosterone implants, depressed population density for more than a year after the implants were exhausted.</p> <p>2. This confirms the observation, also made in previous studies of this territorial species, that aggressiveness can determine population density. Additionally, it hints at a form of social memory that sustains the effect of episodes of high aggressiveness after their cause has ceased to exist.</p> <p>3. We explore the logical consequences of this observation with a simple model of the interaction between population density and aggressiveness. A flexible function describes how aggressiveness changes from year to year as a function of population density. At low densities animals are tolerant to conspecifics and aggressiveness falls from one year to the next. Conversely, at high densities aggressiveness rises.</p> <p>4. In the model, current aggressiveness is set by aggressiveness in the previous year, and modified by last year's population density (first version) or by current population density (second version).</p> <p>5. We assume no particular behavioural mechanism underlying this process but derive conditions under which changes in aggressiveness, effected by density, can generate unstable dynamics.</p> <p>6. The two versions of the model give fluctuations that differ in period and amplitude but have similar conditions for unstable dynamics. Specifically, the more abrupt the transition from tolerant to intolerant behaviour with increasing density, the more likely are cycles to occur.</p> <p>7. We show how a previous model of the kinship hypothesis for red grouse cycles can be recast in the current terminology, and how the new models offer a more general way of examining red grouse population dynamics.</p&gt

Trade-off in ecosystem services of the Somerset Levels and Moors wetlands

It is widely recognised that healthy ecosystems can provide considerable benefits to people, including food, timber, freshwater, protection from floods and much of what we call quality of life. A global review of these ecosystem services carried out as part of the Millennium Ecosystem Assessment (MA) provided a framework for national and local studies. Using the MA approach, this paper reviews the ecosystem services provided by the Somerset Levels and Moors wetland system in south-west England. This wetland provides a series of important services that are beneficial locally, regional and globally, including grazing for cattle, potential carbon sequestration, flood water storage, recreation and archaeology. Some services are synergistic and reinforcing; for example, maintaining wet conditions supports wetland bird life that maintains biological diversity, attracts tourists, protects archaeological artefacts and reduces CO2 emissions. Other services are potentially conflicting, for example raising water levels may reduce potential flood water storage and increase methane emissions. Comparison of the services of the wetland with those of drier habitats reveals for example that carbon sequestration, bird habitat provision and hay production is greater in wetlands, whilst grazing quality and plant diversity may be reduced and distributions of disease vectors may be altered by wetland restoration through raising water levels. Management decisions affecting wetlands may necessitate a trade-off of ecosystem services