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

The Quest for the Cosmological Parameters

Abstract. The following review is based on lectures given in the 1 st Samos Cosmology summer school. It presents an attempt to discuss various issues of current interest in Observational Cosmology, the selection of which as well as the emphasis given, reflects my own preference and biases. After presenting some Cosmological basics, for which I was aided by excellent text-books, I emphasize on attempts to determine some of the important cosmological parameters; the Hubble constant, the curvature and total mass content of the Universe. The outcome of these very recent studies is that the concordance model, that fits the majority of observations, is that with Ωm + ΩΛ = 1, ΩΛ ≃ 0.7, H ◦ ≃ 70 km s −1 Mpc −1, ΩB ≃ 0.04 and spectral index of primordial fluctuations, the inflationary value n ≃ 1. I apologise before hand for the many important works that I have omitted and for the possible misunderstanding of those presented. 1 Background- Prerequisites The main task of Observational Cosmology is to identify which of the idealized models, that theoretical Cosmologists construct, relates to the Universe we liv