Date: March 2010; Version: FINAL Recommended Citation: Liley D., Lake, S., Underhill-Day, J., Sharp, J., White, J. Hoskin, R. Cruickshanks, K. & Fearnley, H. (2010). Welsh Seasonality Habitat Vulnerability Review. Footprint Ecology / CCW. 1 Summary It is increasingly recognised that recreational access to the countryside has a wide range of benefits, such as positive effects on health and well-being, economic benefits and an enhanced understanding of and connection with the natural environment. There are also negative effects of access, however, as people’s presence in the countryside can impact on the nature conservation interest of sites. This report reviews these potential impacts to the Welsh countryside, and we go on to discuss how such impacts could be mapped across the entirety of Wales. Such a map (or series of maps) would provide a tool for policy makers, planners and access managers, highlighting areas of the countryside particularly sensitive to access and potentially guiding the location and provision of access infrastructure, housing etc. We structure the review according to four main types of impacts: contamination, damage, fire and disturbance. Contamination includes impacts such as litter, nutrient enrichment and the spread of exotic species. Within the section on damage we consider harvesting and the impacts of footfall on vegetation and erosion of substrates. The fire section addresses the impacts of fire (accidental or arson) on animals, plant communities and the soil. Disturbance is typically the unintentional consequences of people’s presence, sometimes leading to animals avoiding particular areas and impacts on breeding success, survival etc. We review the effects of disturbance to mammals, birds, herptiles and invertebrates and also consider direct mortality, for example trampling of nests or deliberate killing of reptiles. Within each of these four sections we look across all types of access, but rather than single out particular activities, we highlight general mechanisms such as footfall or wear that result in the particular impact. We include all terrestrial, freshwater and coastal habitats (but exclude coastal habitats that are restricted to the sub tidal and intertidal). We use broad habitat types as our focus, and for each impact we summarise the review according to habitat type, producing a matrix of 24 habitats and four seasons allowing direct comparison of different habitats throughout the year. The final section of the report provides recommendations as to how the information in the literature review could be captured within a GIS to show the seasonal vulnerability of different areas of Wales. We recommend using a grid of 500m cells and a cumulative value calculated for each cell for each season. This score would be derived by summing individual scores (based largely on expert opinion) that capture the following: Soil types present with the grid cell (certain soil types are vulnerable to erosion) Habitats present within the cell (with comparative scores for each habitat finalised through expert opinion) Species present within or near the cell (a list of key species, both plant and animal would be finalised through expert opinion) Further work is necessary to develop the actual maps and we identify the steps required for this to be completed. 2 Crynodeb Cydnabyddir fwyfwy bod mynediad i gefn gwlad at ddibenion hamddena’n esgor ar ystod eang o fanteision, megis effeithiau cadarnhaol ar iechyd a lles, manteision economaidd, dealltwriaeth well o’r amgylchedd naturiol, a chysylltiad cryfach â’r amgylchedd hwnnw. Fodd bynnag, gall mynediad i gefn gwlad esgor ar effeithiau negyddol hefyd, oherwydd gall presenoldeb pobl yno effeithio ar fudd safleoedd, o safbwynt cadwraeth natur. Mae’r adroddiad hwn yn adolygu’r effeithiau posibl hyn ar gefn gwlad Cymru, ac awn ymlaen i drafod sut y gellid mapio’r effeithiau ar draws Cymru gyfan. Byddai map o’r fath (neu gyfres o fapiau) yn adnodd i lunwyr polisïau, cynllunwyr a rheolwyr mynediad, a byddai’n tynnu sylw at y rhannau hynny o gefn gwlad sy’n arbennig o sensitif i fynediad, a gallai lywio gwaith lleoli a darparu isadeiledd mynediad, tai ac ati. Rydym wedi trefnu’r adolygiad ar sail pedwar prif fath o effaith: halogi, difrod, tân ac aflonyddwch. Mae halogi’n cynnwys effeithiau megis sbwriel, cyfoethogi o ran maetholion, ac ymlediad rhywogaethau estron. Yn yr adran ar ddifrod, rydym yn ystyried cynaeafu a’r effeithiau a gaiff troedio ar lystyfiant ac erydiad isbriddoedd. Mae’r adran sy’n sôn am dân yn mynd i’r afael ag effeithiau tân (damweiniol neu fwriadol) ar anifeiliaid, cymunedau planhigion a’r pridd. Fel rheol, canlyniadau anfwriadol presenoldeb pobl yw aflonyddwch, sydd weithiau’n golygu bod anifeiliaid yn osgoi ardaloedd penodol, ac effeithiau ar lwyddiant o ran bridio, goroesi ac ati. Rydym yn adolygu effeithiau aflonyddwch ar famaliaid, adar, amffibiaid ac ymlusgiaid, ac infertebratau, ac yn ystyried marwolaeth uniongyrchol hefyd, er enghraifft, yn sgîl sathru ar nythod neu ladd ymlusgiaid yn fwriadol. Ym mhob un o’r pedair adran hyn, rydym yn edrych ar bob math o fynediad, ond yn hytrach na dewis gweithgareddau penodol rydym yn tynnu sylw at ffactorau cyffredinol megis troedio neu draul, sy’n arwain at yr effaith benodol dan sylw. Rydym yn cynnwys pob cynefin tirol, cynefin dŵr croyw a chynefin arfordirol (ond yn eithrio cynefinoedd arfordirol sydd wedi’u cyfyngu i ardaloedd islanwol a rhynglanwol). Rydym yn defnyddio mathau cyffredinol o gynefinoedd fel ffocws, ac ar gyfer pob effaith rydym yn crynhoi’r adolygiad ar sail y math o gynefin, gan greu matrics o 24 cynefin a phedwar tymor er mwyn ein galluogi i gymharu gwahanol gynefinoedd yn uniongyrchol gydol y flwyddyn. Mae adran olaf yr adroddiad yn rhoi argymhellion ynghylch sut y gellid cynnwys gwybodaeth yr adolygiad llenyddiaeth mewn System Gwybodaeth Ddaearyddol er mwyn dangos pa mor agored i niwed y mae gwahanol ardaloedd o Gymru yn ystod gwahanol dymhorau. Rydym yn argymell defnyddio grid o gelloedd 500m a gwerth cronnus wedi’i gyfrifo ar gyfer pob cell ar gyfer pob tymor. Byddai’r sgôr hon yn cael ei phennu drwy gyfrifo cyfanswm sgorau unigol (wedi’u seilio’n bennaf ar farn arbenigwyr) sy’n cynnwys y canlynol: Y mathau o bridd sy’n bresennol yng nghell y grid (mae rhai mathau o bridd yn fwy tueddol o erydu) Y cynefinoedd sy’n bresennol yn y gell (gyda sgorau cymharol ar gyfer pob cynefin wedi’u pennu drwy farn arbenigwyr) Y rhywogaethau sy’n bresennol yn y gell neu wrth ei hymyl (byddai rhestr o rywogaethau allweddol, sy’n cynnwys planhigion ac anifeiliaid, yn cael ei phennu drwy farn arbenigwyr). 3 Mae angen gwneud mwy o waith i ddatblygu’r mapiau, ac rydym yn nodi’r camau y mae angen eu cymryd i gyflawni hynny. 4 Contents Summary ......................................................................................................................................................... 2 Crynodeb ......................................................................................................................................................... 3 Contents .......................................................................................................................................................... 5 Acknowledgements ......................................................................................................................................... 7 Introduction..................................................................................................................................................... 8 Contamination ............................................................................................................................................... 12 Introduction ................................................................................................................................................... 12 Litter .............................................................................................................................................................. 12 Nutrient Enrichment ....................................................................................................................................... 13 ‘Alien’ plants .................................................................................................................................................. 16 Alien Animals ................................................................................................................................................. 16 Disease........................................................................................................................................................... 17 Particular Habitat Issues and Seasonal Effects ................................................................................................. 17 Damage ......................................................................................................................................................... 21 Introduction ................................................................................................................................................... 21 Damage to substrate - mechanisms ................................................................................................................ 22 General effects of increased ground pressure on substrates ....................................................................................22 Differences between recreation activities ................................................................................................................23