Environmental Statement volume 4 - Chiltern Evergreen3

Site name/area/distance fromdevelopmentQualifying interest (habitats and species),general condition requirements andmanagement measuresBAP Habitat type supporting interest feature:Unimproved neutral grassland with NVCgrassland and inundation communities MG11,MG13 and MG6.The special interest of the site is dependent upongroundwater levels and annual flooding.Several of the component parts are dependentupon traditional hay-cutting and aftermathgrazing.Grazing takes place throughout the year andstocking levels are high. The impact of the highgrazing pressure upon Apium repens is underinvestigation. At present it is thought that thisspecies is tolerant, if not dependent upon thismanagement regime.Groundwater levels and flooding events on PortMeadows are monitored, as is the distribution ofA.repens on site.Gravel extraction is taking place adjacent to oneof the component parts (Pixey and YarntonMeads SSSI). Safeguards and monitoring are inplace to minimise the risk of damage to the sitedue to groundwater changes arising from thisactivity.Conservation objectives Site sensitivities Known vulnerabilityand threatsCreeping marshwort – feature Lowland grasslandNVC types MG6, MG11, MG13Extent Area of suitable habitat – no reduction in areaof suitable habitat and no reduction indistribution pattern. Reduction in area ofsuitable habitat might include effects of dryingout or increasing bare soil. Only known fromPort Meadow and adjacent Binsey Green site.Present in 3 discrete areas of Port Meadow.Sward height 3-10 cm. Specifically in areas known to supportApium repens: 1-5 cm over min 75% of area –short turf to be maintained throughout the year.If outside there maybe excessive or insufficientgrazing. Apium repens is intolerant ofcompetition from surrounding taller vegetation.It is important that short turf is maintainedthroughout the year in these areas.Sward Composition In addition to the common and widespreadspecified species it is desirable to maintainpopulations of the notable characteristic plantsof Port Meadow, ie those which reflect the longhistory of grazing management and wet orcalcareous conditions. The species rich MG6areas are fairly localised and patchy. Somespecified species are typical of NVC typesENVIRONMENTAL RESOURCES MANAGEMENTF7CHILTERN RAILWAYS