Activity
Long-term monitoring in three woodland sites in Oxfordshire (Wytham Woods, Warburg Reserve, Bix) and Buckinghamshire (Sheephouse Wood)

To prepare for the future we need to understand past changes in sites. This is particularly true for woodland where changes may only become clear over decadal timescales. One way that we deal with this is through long-term monitoring of selected sites. Identifying the processes leading to change in these SSSIs can provide a model for likely impacts in other sites. This information then informs advice on site management and provides part of the evidence background for woodland policy development. Wytham Woods (c320 ha) are a mixture of ancient and recent woodland, predominantly broadleaved but with some remnants of coniferous plantations. There are also small areas of limestone grassland. 163 plots were established in 1974 at alternate intersections of a 100 m grid, based on the OS grid. Each plot is 10 x 10 m. Records include information on the tree and shrub layer, ground flora, soils. Re-recording of the whole grid took place in 1991/2, 1999/2001, and is planned for 2011. Other records are available for some plots from 1984/5 and for Marley Wood for most years since 2002. The site is also part of the ECN series and the plots are also included in some of their records. Warburg Reserve, Bix (c110 ha) are a mixture of former beech wood-pasture and coppice, recent plantations and chalk grassland. 107 plots set out at intersections of 100m grid. The plots are similar to those described for Wytham Woods (but no soil records made). The original records were made in 1973; full re-recording took place in 1992 and in 2008/10. Sheephouse Wood is c50 ha of oak-hazel coppice that was promoted to high forest in the nineteenth century. Since 1981 periodic surveys have been made using a mixture of a small number (10) temporary and permanent plots to look at tree and shrub and ground flora changes.Key factors driving change include canopy growth and gap formation, deer numbers. Major shifts have occurred in some woodland plants such as bramble.