Securing Biodiversity in Breckland - European Commission

Management to Sustain Dry Terrestrial AssemblagesIn this section we provide guidelines for land managers to support and enhance the variousassemblages of priority species for conservation in Breckland. We also identify areas of uncertainty,recommendations for research and emphasise the need for monitoring outcomes.An important priority must be to restore appropriate conditions for specialist assemblages ofBreckland conservation priority species across the existing resource of designated sites, includingboth statutory (SSSIs) and non-statutory (CWS). At many terrestrial sites, there is a lack of disturbedground with dominance by later successional stages. Many sites are managed by homogenousgrazing regimes and would benefit from some heterogeneity of sward structures, creation of nectarresources and juxtaposition of ungrazed disturbed ground.Current approaches to grass-heath managementWe were able to compile habitat management questionnaire responses for a total of 2,446 ha ofBreckland grass-heath, covering most key heath SSSIs. Of this area, all but 45 ha was grazed (98.2%grazed), with sheep used to graze all sites. Cattle were also present on areas of one large heathland.The intensity of sheep grazing varied between sites and compartments. While grazing intensity wasdescribed as moderate or high (e.g. Thetford Heath, c. 25 ewes ha -1 ) on many sites (comprising 41%of the aggregate area), on 32% of the aggregate area sheep density was described as low or light (e.g.c0.7 ewes ha -1 , 0.8 ha -1 , 1.5 ha -1 and 2 ha -1 ). Grazing density information was not obtained for theremaining area. Considering just the area for which sheep density was supplied, 57% was moderateto high, but 43% had low intensity of grazing.Rabbit population density was described as virtually absent to low on 57% of the total grass-heath,and as moderate to high for 25%. When just the sites for which we obtained rabbit information wereconsidered, 70% had no or very few rabbits.Qualitative assessment of the extent of bare ground was available from 95.5% of the area of grassheath.Bare ground was described as:very rare or rare: 52%occasional: 25%abundant : 19%Accurate information quantifying the extent of physical disturbance treatments was available for 9SSSIs covering a total of 1387 ha. Across these, physical disturbance plots amounted to 11 ha, or0.8% of the area. It should be noted that these include key sites in which disturbance treatmentshave been pioneered and most widely applied. Thus, across the grass-heath conservation resourcephysical disturbance will amount to much less than 1%.In conclusion although some sites receive intensive sheep grazing, and some sites have rabbits, 43%of sheep grazed area was managed by low intensity grazing, 70% of the area extent had no or fewrabbits and disturbance treatments covered less than 1% of the grass-heath extent.147