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

Abstract

It is widely recognized 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 (MEA) provided a framework for national and local studies. Using the MEA approach, this paper reviews the ecosystem services provided by the Somerset Levels and Moors wetland system in southwest England. This wetland provides a series of important services that are beneficial locally, regionally and globally, including grazing for cattle, 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 CO 2 emissions; raising water levels to or above the ground leads to net greenhouse gas uptake by the wetland. 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 may decline and plant diversity may be reduced in the short term 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.Key words ecosystem services; wetlands; Somerset Levels and Moors; ecosystem function; floods; water resources; carbon sequestration; tourism; archaeology Compromis entre les services écosystémiques des zones humides "Somerset Levels and Moors"Résumé Il est largement reconnu que des écosystèmes sains peuvent fournir des avantages considérables aux personnes, comprenant de la nourriture, du bois, de l'eau douce, la protection contre les inondations et une grande partie de ce que nous appelons la qualité de vie. Un examen global de ces services écosystémiques, réalisées dans le cadre du Millennium Ecosystem Assessment (MEA), a fourni un cadre pour des études nationales et locales. En utilisant l'approche MEA, le présent article passe en revue les services écosystémiques fournis par les zones humides "Somerset Levels and Moors" situées dans le sud de l'Angleterre. Ces zones humides fournissent une série de services importants qui sont bénéfiques au niveau local, régional et mondial, comprenant le pâturage pour le bétail, la séquestration du carbone, le stockage des eaux de crue, les loisirs et l'archéologie. Certains services sont en synergie et, par exemple, le maintien des conditions humides favorise la vie des oiseaux des milieux humides et maintient la diversité biologique, attire les touristes, protège des objets archéologiques et réduit les émissions de CO 2 ; élever les niveaux ...

Micro-climate influence on reference evapotranspiration estimates in wetlands

“…As this work has shown, the precision of individual sensors must be considered when dealing with such small differences. Wicken Fen may also be said to be providing a climate regulation ecosystem service, as identified by Acreman et al (2011). …”

“…Huryna et al (2014) measured 30% more evaporation from a wet meadow than from pasture and arable fields, suggesting this contributes significantly to the cooling of agricultural landscapes. Acreman et al (2011) identified a lower temperature within the Somerset Levels and Moors, UK, compared to outside the wetland as a result of higher evapotranspiration and Raney et al (2014) identified significantly different soil temperatures within temperate fens relative to surrounding uplands.…”

A simple model to quantify the potential trade-off between water level management for ecological benefit and flood risk

“…The SLMs cover an area of 650 km 2 and consist of low-lying organic peat soils underlain by marine silts and clays, which form an impermeable sub-layer. They are the largest remaining area of lowland wet grassland in England (more than 20% of the resource) and include 18 Sites of Special Scientific Interest (SSSIs) covering 7200 ha, 12 of which (6300 ha) are Special Protection Areas under the European Habitats Directive, with most of the area designated as a Ramsar site under the International Convention on Wetlands (Acreman et al, 2011).…”

“…Whilst raising water levels may support delivery of some ecosystem services, others may be lost or reduced. Acreman et al, (2011) looked at the effect of various management practices on the extensively drained Somerset Levels and Moors and found that raised water levels increased delivery of services, such as carbon sequestration, climatic regulation, biodiversity (in the long term) and recreation and education. They also found that food production, freshwater availability, biodiversity (in the short term) and flood storage were reduced.…”

How effective are reedbeds, ponds, restored and constructed wetlands at retaining nitrogen, phosphorus and suspended sediment from agricultural pollution in England?

“…Phosphorus removal has been shown to correlate positively with an increase in wetland area, and a minimum wetland to farmyard area ratio of 1.3 has been proposed for effective removal of molybdate reactive phosphorus (MRP) [11]. When deciding on wetland size, other factors such as ecosystem services [12,13] should also be considered as discussed below.…”