Monitoring Status 2014 and Strategy
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VC17 Monitoring Status 2014 and Strategy Monitoring Status 2014 and Strategy Introduction A large number of UKBMS transects are walked within VC17 – Surrey every year. However, are these transects monitoring what needs to be monitored? This is the question that this paper attempts to address, by analysing what species need to be monitored, and what locations need to be monitored. Resources are limited, so transects need to be located where they will achieve the greatest benefit. Priority should be given to monitoring different habitats within VC17, protected areas, and species that are a priority for conservation. However, it is recognised that volunteers will want to walk transects that are close to where they live, and that are good habitats for butterflies. It is recognised that this can result in difficulties in trying to monitor particular areas because of their remoteness, or maybe restricted butterfly abundance. Habitats Natural England has defined 159 National Character Areas (NCAs) which share similar landscape characteristics, and which follow natural lines in the landscape rather than administrative boundaries, making them a good decision-making framework for the natural environment. There are ten NCAs that occur within the boundaries of VC17 – Surrey, although three of these, North Kent Plain, Hampshire Downs and the High Weald, are only very partially within the boundaries of VC17. Thames Valley is mostly outside of VC17, but includes important sites such as Richmond Park and Wimbledon Common so are included. Only the Thames Basin Lowlands is nearly all contained within VC17, a significant proportion of the other NCAs occur outside of the county. There are three principal habitats that occur within VC17 that effect the butterfly populations found within them Chalk represented by the North Downs Sand, which provide heath habitats are represented by the Thames Basin Heaths and Wealden Greensand Clay are represented by the Thames Basin Lowlands and Low Weald Canopy Butterflies The following species are canopy butterflies, which are widespread throughout VC17 – Surrey, but are hard to monitor by traditional means: Brown Hairstreak Purple Emperor Purple Hairstreak White-letter Hairstreak Page 1 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Monitoring Strategy 1. Ensure each NCA is monitored in the west, centre and east of VC17 (where applicable) 2. Ensure all conservation priority species in each NCA are monitored at least two sites 3. Ensure that key sites within each NCA is monitored. 4. Ensure that each Hectad is monitored. Key Hectads The map below shows the 33 hectads (10km squares) within the VC17 recording area. Key Sites RAMSAR sites are wetlands of International importance SAC (Special Area of Conservation) sites are of European importance to conserve key habitats and species SPA (Special Protection Area) sites are of European importance to conserve vulnerable birds SSSI (Sites of Special Scientific Interest) sites are of National importance to conserver key habitats and species. NNR (National Nature Reserves) are key places for wildlife and natural features in England Page 2 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Priority Species The table below shows the Surrey butterflies that have protection under the Schedule 5 of the Wildlife & Countryside Act 1981 from harm or sale. Section 41 of the Natural Environment & Rural Communities Act 2006 lists those species which are of principal importance for conserving biodiversity in England (also known as BAP species). JNCC’s Red List of Butterflies for Great Britain, 2010 provides the list of butterflies at risk from extinction, EN=Endangered, VU=Vulnerable, NT=Near Threatened, with butterflies of LC=Least Concern being excluded. Wildlife & Sect.41 JNCC Butterfly Countryside Action Red List Act List Adonis Blue Sch5 NT Brown Hairstreak Sch5 Medium VU Chalkhill Blue Sch5 NT Dingy Skipper Low VU Glanville Fritillary Sch5 Low EN Grayling Low VU Grizzled Skipper Low VU Purple Emperor Sch5 NT Silver-spotted Skipper Sch5 Medium NT Silver-studded Blue Sch5 VU Small Blue Sch5 Medium NT Small Heath Low NT White Admiral Low VU White-letter Hairstreak Sch5 Medium EN Wood White Sch5 Medium EN Page 3 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Inner London Character 100% urbanised with a population of 3m+ (2001 census). The soils are alluvial gravels overlying London Clay. Rivers within VC17 part of Inner London are the Thames and Wandle. Main Hectads Eastern Hectads – TQ27, TQ37 Key Locations SAC & NNR – Richmond Park (most of the park is in Thames Valley) SAC – Wimbledon Common (part in Thames Valley) Priority Species Purple Emperor Small Heath White Admiral White-Letter Hairstreak Page 4 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Thames Valley Character The Thames Valley predominately occurs in Berkshire and Buckinghamshire, only a small proportion occurs within Surrey. Sands and gravels overly London Clay. Mainly agricultural (44%), with large urban (33%) areas, remaining woodland (13%). Population 1.5m (2001 census) Rivers Thames flows through the Thames Valley. Main Hectads Central hectads – TQ16, TQ17 Eastern hectads – TQ27 Key Locations RAMSAR – South West London Water Bodies (part only) SSSI – Knight & Bessborough Reservoirs SSSI – Thorpe Park No. 1 Gravel Pit SAC & NNR – Richmond Park (small part in Inner London) SAC – Wimbledon Common (part in Inner London) SSSI – Barns Elms Wetland Centre London Wetland Centre SSSI – Langham Pond, including Runneymeade SSSI – Windsor Forest & Great Park (main part in Berkshire) Priority Species Purple Emperor Small Heath White Admiral White-Letter Hairstreak Page 5 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Thames Basin Lowlands Character London Clay, 59% urbanised, population <1m (2001 census), oak woodlands (13%), and remaining 33% agricultural. Rivers Wey, Mole, Hogsmill and Wandle flow through the NCA. Main Hectads Western hectads – SU95 Central hectads – TQ05, TQ15, TQ16 Eastern hectads – TQ26, TQ36 Key Locations SSSI – Epsom and Ashtead Commons NNR – Ashstead Common SSSI – Esher Commons, including: Fairmile Common SSSI – Bookham Common Priority Species Brown Hairstreak Purple Emperor (key) Silver-studded Blue (Fairmile Common) Small Blue Small Heath White Admiral White-Letter Hairstreak Page 6 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Thames Basin Heaths Character Sands and gravels, which allow heathland to flourish. Agricultural (63%), woodland (18%), urban (13%). Population <0.8m (2001 census) Rivers Wey, Mole, Blackwater and Bourne, and the Basingstoke canal all flow though the Thames Basin Heaths. Main Hectads Western hectads – SU95, SU96 Central hectads – TQ05, TQ06 Key Locations SAC – Thursley, Ash, Pirbright & Chobham (part), consisting of: SSSI & NNR – Chobham Common SSSI - Colony Bog and Bagshot Heath, including o Brentmoor Heath SSSI - Ash to Brookwood Heaths SPA – Thames Basin Heaths, includes all those in the SAC SSSI – Whitmoor Common SSSI – Basingstoke Canal SSSI – Horsell Common SSSI – Ockham & Wisley Commons SSSI – Smarts & Prey Heaths SSSI - Papercourt Priority Species Grayling Grizzled Skipper (one site only) Purple Emperor Silver-studded Blue Small Heath White Admiral White-Letter Hairstreak Page 7 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy North Downs Character Chalk Hills topped with clay, giving rise to Beech woodlands on the slopes and oak woodlands on the clay. Key habitat are the chalk grasslands Predominately agricultural (80%), urban (9%) and woodland (1%). Population <0.6m (2001 census) Rivers Wey and Mole bisect the North Downs Main Hectads Western hectads – SU84, SU94 Central hectads – TQ04, TQ05, TQ15 Eastern hectads – TQ25, TQ35, TQ36 Key Locations SAC - Mole Gap to Reigate Escarpment, includes the following sites: Norbury Park Box Hill Headley Warren Headly heath Brookham Betchworth Buckland Hills Colley Hill SSSI - Mole Gap to Reigate Escarpment, includes SAC sites and Wingate Hill SSSI – Wey Hill Meadows SSSI – Colyers Hanger SSSI – Combe Bottom SSSI – Sheapleas SSSI – Hackhurst & White Downs, including: Hackhurst White Downs Blatchford Down Denbies Hillside SSSI – Ranmore Common SSSI – Banstead Downs SSSI – Chipstead Downs, includes Banstead Wood Park Downs SSSI – Farthings Downs & Happy Valley SSSI – Quary Hangers SSSI – Riddlesdown SSSI – Woldingham & Oxted Downs Priority Species Adonis Blue Brown Hairstreak Page 8 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Chalk Hill Blue Dingy Skipper Glanville Fritillary (Hutchnison Bank only) Grizzled Skipper Purple Emperor Silver-spotted Skipper Small Blue Small Heath White Admiral White-Letter Hairstreak Page 9 of 27 Butterfly monitoring © Harry E. Clarke 2015 VC17 Monitoring Status 2014 and Strategy Wealden Greensand Character Sandy Soils to loam. Heathlands are dominant to the west. Predominately agricultural (70%), woodland (25%) and urban (7%). Population is >0.6m (2001 census) Rivers Wey and Mole flow through the area. Main Hectads Western hectads – SU84, SU93, SU94 Central hectads – TQ04, TQ14 Eastern hectads – TQ25, TQ35 (possibly) Key Locations RAMSAR - Thursley & Ockley Bogs (also a SAC and