Figure 3.6: Eversden & Wimpole Wood SSSI and SAC

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3.7 Figure 3.6 above demonstrates that whilst the bulk of Eversden Wood is located in excess of 200m from local roads, elements of the SAC, namely ‘The Belts’ are located adjacent to an unnamed road which links local farms. Therefore, the potential for development related affects associated with this road has been further assessed.

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4 SSSI Citations for Pre-Screened Sites

4.1 SSSI are declared as a result of their specific fauna, flora or geological or physiological features and usually as a result of a combination of all of these factors. The declaration of a SSSI is associated with the production of a ‘citation’ for the site, which sets out those attributes for which the site is of ‘special scientific interest’. Extracts of the citations for each of the sites of interest and their formal ecological classifications are provided below.

Caldecote Meadows SSSI

4.2 Caldecote Meadows is a 3.19 hectare area of herb-rich grassland of a calcareous loam type, holding plant communities which are of nationally restricted distribution. Meadows of this type were once widespread throughout Cambridgeshire but are now scarce in the county.

Condition: Favourable

Main Habitat Classification: Neutral Grassland - Lowland

Overhaul Grove SSSI

4.3 Overhall Grove is a 17.3 hectare site of ancient secondary woodland now dominated by small-leaved elm Ulmus minor and represents a woodland type which is nationally restricted in its distribution. The wood overlies the site, fields and ponds of a medieval manor house and was well established by 1650. The break, or discontinuity, in tree cover with no primary woodland nucleus remaining has resulted in a classic example of the long-lasting effects on the ground flora of the removal of woodland cover.

Condition: Unfavourable Recovering

Main Habitat Classification: Broadleaved, Mixed and Yew Woodland

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Maddingley Woods SSSI

4.4 Madingley Wood is a 15.4 hectare example of the ash-maple woodland type characteristic of the chalky Boulder Clay of eastern England. The western sector of the wood is of ancient origin whilst the eastern half is of relatively recent origin thus providing valuable opportunities for study into colonisation processes and historical ecology generally.

4.5 The site is of particular educational and research value in view of its long association with the University of Cambridge.

Condition: Favourable

Main Habitat Classification: Broadleaved, Mixed and Yew Woodland

Eversden and Wimpole Wood SSSI and SAC

4.6 Eversden Wood has been declared as a SSSI as a result of its status as important ancient semi-natural woodland of a type now localised in extent, and rare in lowland England. It has also been declared an SAC as a result of the presence of a summer maternity roost for the barbastelle bat, Barbastella barbastellus. Wimpole Wood is considered to be of more recent origin.

Condition: Unit 003 Unfavourable Recovering. Unit 004 Favourable

Main Habitat Classification: Broadleaved, Mixed and Yew Woodland

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5 Further Assessment Criteria

5.1 The pre-screening presented in Section 3 has identified Caldecote Meadows, Overhaul Grove, Madingley Wood and elements of Everston & Wimpole Wood as requiring further assessment by virtue of their distance from potentially affected roads. This further screening stage has necessitated a review of the likelihood that traffic volumes associated with the Application Site, in combination with other local development, may travel passed the identified SSSI and SAC at levels which could potential effect the integrity of the habitats for which their designations have been given. This is further discussed below.

Critical Loads

5.2 Critical Loads are defined on the Air Pollution Information Systems (APIS) website 3 as “ a quantitative estimate of exposure to one or more pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur according to present knowledge ”

5.3 Therefore, it is reasonable to assume that if exposure above the critical load will have ‘... harmful effects on specified sensitive elements of the environment ...’ then the integrity of the site is thus affected. 5.4 Nutrient Nitrogen deposition is identified within Annexes A and B as the main pollutant of concern within these habitats. The Critical Loads of Nutrient Nitrogen across the potentially affected habitats identified range from 10 – 30(kg/N/ha/yr), therefore for the purpose of this further screening a worst value of 10 (kg/N/ha/yr) has been applied.

5.5 A full examination of the Nutrient Nitrogen critical loads used within this assessment is contained within Annex C.

3 www.apis.ac.uk/overview/issues/overview_Cloadslevels.htm

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Significance

5.6 In accordance with the Annex F of the EA’s Horizontal Guidance on Air Emissions, the significance of impact has been derived from an examination of whether an air quality impact is likely to constitute more than 1% of the critical load for Nitrogen deposition 4. Traffic Data

5.7 Previous HRA Screening work 5 undertaken by Mayer Brown identified that Annual Average Daily Traffic (AADT) Flows of 120 were associated with Nutrient Nitrogen deposition levels within 10m of the road that were likely to be 0.5% of the critical load of 10 kg/N/ha/yr. Therefore, this has been used as the trigger level for traffic flows to be assessed within this HRA air quality screening exercise.

5.8 Therefore, the need for detailed assessment is proposed where any roads located within 200m of the SAC are subject to increases of Annual Average Daily Traffic of more than 120 as a result of the development either alone or in- combination with other foreseeable development.

5.9 The transport assessment has concluded the following:

Caldecote Meadows SSSI

5.10 AADT Traffic flows associated with the Application Site within 200m of this SSSI are anticipated to be around 56 in the development year of 2031. AADT traffic flows for the same location and in combination with other plans or projects for the development are anticipated to be approximately 97.

5.11 Therefore, this level of traffic is not considered to be of a level which would result nutrient nitrogen disposition within the SSSI which is above 0.5% of the critical load.

4 Environment Agency (2011) Horizontal Guidance – H1 Annex F - Air Emissions. EA. Bristol 5 Mayer Brown (2015) Horton Heath HRA Screening Addendum. MB. Woking

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Overhaul Grove SSSI

5.12 Given that traffic approaching Overhaul Grove would be required to take the same route as that approaching Caldecott Meadows, the same conclusion can be drawn. This is that AADT traffic either alone or in combination with other plans and projects would not be considered to be of a level which would result nutrient nitrogen disposition within the SSSI which is above 0.5% of the critical load for this site.

Maddingley Woods SSSI

5.13 The transport assessment has concluded that AADT Traffic flows associated with the Application Site and other plans and projects, travelling to the east along with the A428 would be approximately 12891. In addition, AADT Traffic flows associated with the Application Site and other plans and projects travelling adjacent to the woods on the A1303 would be approximately 8,336. As a result, this exceeds the identified trigger level and further assessment is required of this potential impact.

Eversden and Wimpole Wood SSSI and SAC

5.14 In order to reach the Eversden and Wimpole Wood SSSI and SAC, traffic associated with the Application site would be required to travel south along Broadway before joining the A1198 and then taking Old Wimpole Road to the east. The Transport Assessment has concluded that less that 1% of the Application Site AADT and that of other plans and projects, would take this route from the Broadway South. This equates to an AADT of approximately 15. Therefore, it can also be concluded that this level of traffic is not considered to be of a level which would result nutrient nitrogen disposition within the SSSI which is above 0.5% of the critical load.

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6 Detailed Assessment

Assessment Model

6.1 A quantitative assessment of traffic related air quality impacts on the Maddingley Wood SSSI has been undertaken. The modelling tool which has been used is the dispersion model ADMS Roads, which has been developed by the Cambridge Environmental Research Consultants. It is one of the screening models referred to within the Local Air Quality Management Technical Guidance document TG (09) Annex 2: Estimating Emissions 6.

6.2 This model uses the following input data: • Hourly Average Traffic Speeds - derived from diurnal traffic counts and provided by the transport consultants; • Latest relevant Emission Factor Toolkit (Version 8); • Geo-referenced mapping data; and • Hourly Sequential ADMS format MET data for Luton Airport the year 2016.

6.3 All other modelling assumptions and criteria are set out within the Mayer Brown Air Quality Assessment 7

Study Scenarios

6.4 Traffic related nitrogen disposition associated with the operation of the proposed development has been assessed for the following scenarios.: • The predicted levels for Nitrogen deposition at Madingley Wood in the baseline year of 2031, associated with both the A428 and the A1303 including for flows from the Application Site; and • The predicted levels for Nitrogen deposition at Madingley Wood in the development year of 2031, associated with both the A428 and the A1303 including for flows from the Application Site and those from ‘other plans and projects’ i.e. committed development.

6 Department for Environment, Food and Rural Affairs (2009) Local Air Quality Management Technical Guidance LAQM, TG (09). DEFRA. London 7 Pestana, L. (2018) Countryside Properties (UK) Ltd Bourn Airfield, Bourn. Mayer Brown Ltd. Woking

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Traffic Data

6.5 Traffic data for the above scenarios has been provided by Mayer Brown. Consultation has taken place with Cambridgeshire County Council (CCC) to agree schemes that should be included within the Transport Assessment, based upon traffic generation thresholds and relationship with the proposed development. The traffic flows assessed in this study have included for committed developments proposed to come forward within the temporal scope of the development proposals.

Receptor Locations

6.6 The receptors, which have been assessed, are locations where the SSSI is in the closest proximity to affected roads i.e. worst case. The receptor locations examined are set out in Table 6.1 below and are illustrated in Figure 6.1 .

Receptor Locations. Receptor Description A428 Receptors modelled at closest points to road (128m) and then at 5m points up to 200m. A1303 Receptors modelled at closest points to road and then

at 5m points up to 200m.

Table 6.1: SAC Receptor Locations

6.7 Table 6.1 above, demonstrates that the locations chosen are those sections of the SSSI unit in closest proximity to the road and therefore the potentially worst affected.

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Figure 6.1: Specific Air Quality Modelling Locations A428 and A1303

Calculation Methodology

6.8 The rates of Nutrient Nitrogen deposition associated with future traffic scenarios are described as the Process Contribution (PC). The PC of Nitrogen deposition is initially calculated within the ADMS model as a concentration of Oxides of

Nitrogen (NO x). This is then converted to a Nitrogen Dioxide (NO2) quantity

8 using the NO x to NO 2 converter on the UK-Air website . The anticipated quantities of Nutrient Nitrogen deposition at the modelled locations are then estimated using the relationship below which has been derived from the EMEP Eulerian photochemistry model 9.

3 -1 -1 1µ/ of NO 2 = 0.1 kgN ha yr

6.9 This model has been developed by The European Monitoring and Evaluation Programme which is a scientifically based and policy driven programme under the Convention on Long-range Transboundary Air Pollution (CLRTAP) for international co-operation to solve transboundary air pollution problems.

8 http://laqm.defra.gov.uk/review-and-assessment/tools/background-maps.html#NOxNO2calc 9 Highways Agency (2007) Design Manual for Road and Bridge – Assessment of Designated Sites Volume 11 Section 3 Part 1 HA 207/07 Annex F. HA.

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6.10 Worst-case PC upon the SSSI has been quantitatively assessed by modelling the baseline PC in comparison to PC (alone and in-combination with foreseeable development) in the development year with and without the development. The resultant predicted changes in Nutrient Nitrogen deposition have then been assessed against the stated assessment criteria in order to establish the significance of any impact upon the integrity of the Madingley Woods SSSI.

Assessment Criteria

6.11 As previously discussed, the ‘critical load’ of Nitrogen for a site is based upon the individual requirements of its flora and fauna. For Madingley Woods, the main habitat is classified as Broadleaved, Mixed and Yew Woodland. The critical load for this habitat at this location is defined within APIS as within 15 – 20 Kg N ha - 1yr -1.

6.12 As discussed in Section 5 , the significance of impact is derived from an examination of whether an air quality impact is likely to constitute more than 1% of the critical load for Nitrogen deposition, therefore it follows that a PC of less than 0.15 Kg N ha -1yr -1 would indicate no significant effect at this location.

Geographical Scope

6.13 The geographical scope of the assessment is discussed in detail in Section 3 .

Assumptions and Limitations

6.14 A full discussion of the limitations of the modelling process is set out in the supporting air quality assessment.

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7 Results

7.1 Whilst Madingley Woods is SSSI only and not classified as an SAC and therefore not under the same level of European protection or subject to the same requirements of assessment of effect, this screening has never-the-less applied the same level of assessment as provided for the protection of SAC. To this end, Indicative Predicated Environmental Concentrations (PEC) of Nutrient Nitrogen for the habitat in question, have been taken from the APIS website and are set out in Table C1 in Annex C. It is noted that Current PEC of rates for this location average 27.4 Kg N ha -1yr -1 and are in exceedance of the critical loads for Nutrient Nitrogen within this habitat.

7.2 The 2031 baseline air quality environment has been established by modelling the baseline 2031 traffic levels plus committed development flows associated with both the A428 and the A1303. The Nutrient Nitrogen PC associated with the 2031 baseline process contribution rates at the identified receptor sites is set out in Table 7.1 below.

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N_70 0.04 S_70 0.04 N_75 0.04 S_75 0.04 N_80 0.04 S_80 0.04 N_85 0.04 S_85 0.04 N_90 0.04 S_90 0.04 N_95 0.03 S_95 0.04 N_100 0.03 S_100 0.03 N_105 0.03 S_105 0.03 N_110 0.03 S_110 0.03 N_115 0.03 S_115 0.03 N_120 0.03 S_120 0.03 N_125 0.03 S_125 0.03 N_130 0.03 S_130 0.03 N_135 0.03 S_135 0.03 N_140 0.03 S_140 0.03 N_145 0.03 S_145 0.03 N_150 0.03 S_150 0.03 N_155 0.03 S_155 0.03 N_160 0.03 S_160 0.03 N_165 0.03 S_165 0.03 N_170 0.03 S_170 0.03 N_175 0.03 S_175 0.03 N_180 0.03 S_180 0.03 N_185 0.03 S_185 0.03 N_190 0.03 S_190 0.03 N_195 0.03 S_195 0.03 N_200 0.03 S_200 0.03 Table 7.1: Modelled 2031 Nutrient Nitrogen Process Contribution Rates at Madingely Wood as a Result of Baseline and Committed Development Flows

7.3 The PC rates in Table 7.1 demonstrate that there is no exceedance of the 1% Critical Load criteria on the northern side of Madingley Wood, as a result of the baseline and committed development flows on the A428.

7.4 Table 7.1 does however indicate that there is a small exceedance of around 0.02 Kg N ha -1yr -1 on the southern side of the woods, as a result of baseline and committed development flows.

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A428 A1303 2031 PC Nutrient 2031 PC Nutrient A428 Nitrogen Process A1303 Nitrogen Process Receptor Contribution Receptor Contribution Rates Rates Kg N ha -1yr -1 Kg N ha -1yr -1 N_0 0.06 S_0 0.19 N_5 0.06 S_5 0.15 N_10 0.05 S_10 0.13 N_15 0.05 S_15 0.11 N_20 0.05 S_20 0.10 N_25 0.05 S_25 0.09 N_30 0.05 S_30 0.08 N_35 0.05 S_35 0.07 N_40 0.05 S_40 0.07 N_45 0.05 S_45 0.06 N_50 0.05 S_50 0.06 N_55 0.04 S_55 0.06 N_60 0.04 S_60 0.05 N_65 0.04 S_65 0.05 N_70 0.04 S_70 0.05 N_75 0.04 S_75 0.05 N_80 0.04 S_80 0.05 N_85 0.04 S_85 0.04 N_90 0.04 S_90 0.04 N_95 0.04 S_95 0.04 N_100 0.04 S_100 0.04 N_105 0.04 S_105 0.04 N_110 0.04 S_110 0.04 N_115 0.04 S_115 0.04 N_120 0.04 S_120 0.04 N_125 0.04 S_125 0.04 N_130 0.04 S_130 0.03 N_135 0.04 S_135 0.03 N_140 0.04 S_140 0.03 N_145 0.04 S_145 0.03 N_150 0.04 S_150 0.03 N_155 0.04 S_155 0.03 N_160 0.04 S_160 0.03 N_165 0.04 S_165 0.03 N_170 0.04 S_170 0.03 N_175 0.04 S_175 0.03 N_180 0.04 S_180 0.03

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N_185 0.04 S_185 0.03 N_190 0.04 S_190 0.03 N_195 0.04 S_195 0.03 N_200 0.04 S_200 0.03 Table 7.2: Modelled 2031 Nutrient Nitrogen Process Contribution Rates at Madingely Wood as a Result of Baseline, Committed Development and Application Site Flows

7.5 The PC rates in Table 7.2 above demonstrate that there is still no exceedance of the 1% Critical Load criteria on the northern side of Madingley Wood even when the application site flows are added to those of the committed development on the A428.

7.6 However, Table 7.2 does also indicate that there is an incremental exceedance of around 0.04 Kg N ha -1yr -1 on the southern side of the woods as a result of baseline, committed development and Application Site flows.

7.7 This would indicate a potential for development flows, in combination with other plans and projects to have an effect upon the integrity of the SSSI at Madingley Wood.

Effect upon Site Integrity

7.8 The potentially affected area of the wood is seen to comprise a strip of approximately 10m in width and 35m in length. Taking a cautionary approach, it is assumed that an area of land approximately 20m in depth and 40m in length may be affected. This equates to 0.08 hectares.

7.9 The SSSI citation details obtained from Multi Agency Geographic Information System website, cite the Madingley Woods SSSI of be of 15 hectares in size.

7.10 Therefore, it can be concluded that where all precautionary modelling approaches are taken and the most stringent critical load criteria are applied, an area of SSSI equating to 0.5% may be affected by traffic flows from the Application Site in combination with other plans and projects. It is proposed here

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that a potentially affected area of 0.5%, adjacent to a heavily trafficked road, would not affect the integrity of the over-all site.

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8 Conclusion

8.1 This screening has demonstrated that the following SSSI have been screened out of potential effects associated with the Application Site, by virtue of their lack of defined proximity to local roads: • Hardwick Woods SSSI; • Elsworth Woods SSSI; and • Papworth Wood SSSI

8.2 The screening has also demonstrated that the following SSSI have been screened out of potential effects associated with the Application Site, by virtue of traffic flows falling below the defined potential for effect: • Calecote Meadows SSSI; • Overhaul Grove SSSI; and • Eversden & Wimpole Wood SSSI and SAC.

8.3 Where the screening process has identified the potential for effect upon Madingley Woods, a full dispersion modelling study has been undertaken which has concluded the following; • There is no exceedance of the 1% Critical Load criteria on the northern side of Madingley Wood as a result of the baseline and committed development flows on the A428; • There is no exceedance of the 1% Critical Load criteria on the northern side of Madingley Wood as a result of the baseline, committed development and Application Site flows on the A428; • There is a small exceedance of the 1% Critical Load criteria on the southern side of Madingley Wood as a result of the baseline and committed development flows on the A1303; • There is an incremental exceedance of the 1% Critical Load criteria on the southern side of Madingley Wood as a result of the baseline, committed development and Application Site flows on the A1303;

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• Where a precautionary approach is taken, applying the most stringent criteria to the maximum area potentially effected, an area of SSSI equating to 0.5% of the whole may be affected by traffic flows from the Application Site. This is not considered to materially affect the integrity of the SSSI.

8.4 Therefore, this screening assessment can conclude that the Application Site is not considered to materially affect the integrity of any local SSSI or SAC, either alone, or in combination with other plans or projects.

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ANNEX A: NITROGEN DEPOSITION – EFFECTS, IMPLICATIONS AND KEY CONCERNS FOR IDENTIFED MADINGLEY WOOD - APIS 10

Trees • Increased growth, greatest where soil organic layer C:N ratio is high. • Destabilisation; faster growth, reduced investments in roots leading to increased risk of drought stress (Anders et al 2002) and increased risk of uprooting. Damage to mature beech in the 1999 storm in Switzerland positively correlated with leaf N (Meyer et al. 2008) • Nutrient imbalance, crown discoloration ( chlorosis / yellowing) associated with base cation, Mg and K deficiency leading to reduced growth rates, reduced crown densities and abnormal branching patterns. • Change in mycorrhizal flora and reduction in the numbers of large

+ sporocarps, fruiting bodies, which appear particularly sensitive to NH 4 . Sensitive mycorrhizas are replaced by those preferring rich conditions, which tend to be those that are efficient at taking up P. • Increased litter production

+ • N accumulation as NH 4 or amino acids leading to increased sensitivity to abiotic and biotic stress - reduced frost hardiness, associated with effects on late growth cessation and early bud burst, as young tissue is highly frost sensitive. • Winter desiccation; increased defoliation by leaf feeders; increased pathogen infection, though evidence is reported predominantly for beech.

Under-storey vegetation, ground dwellers and epiphytes • Loss of species diversity (Haines-Young et al. 2003; Kirby et al. 2005). • Loss of sensitive forbs and mosses and increases in nitrophilous plants especially grasses. • Loss of ground dwelling Cladinas (Strengbom et al 2001). • Loss of lichens with blue green algae (N fixing), particularly sensitive (Goransson 1990). Lichens with both green algae and cyanobacteria as their photobiont (photosynthetic partner) appeared to be more resilient (Dahlmann 2002).

10 Evidence Base for Effects and Implications and Key Concerns cited at www.apis.ac.uk

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• Pleurococcoid algae that grow epiphytically can be stimulated by even quite small amounts of N deposition (Bobbink et al 1996) particularly if P and K are available e.g. in rural areas. • Epiphytes growing on Oak are highly sensitive, particularly to ammonia, probably mediated via increases in bark pH (Ter Braak).

Soil chemistry and soil fauna • N deposition has the potential to decrease soil pH (e.g. acidification):

+ - NH 4 may be retained by the system or nitrified to NO 3 , releasing 2 moles H+. Nitrate can leach out, if not consumed by the vegetation or microbial population. Leaching has the potential to remove base cations, and reduce soil buffering capacity, (acid cations e.g. H + and Al 3+ can also be leached) through the mobile anion concept (Reuss and Johnson 1985).

+ Thus in systems that cannot fully retain NH 4 its deposition will cause acidification.

• Gaseous ammonia (NH 3) deposition initially increases pH because in

+ + contact with water it ionises, consuming H to form NH 4 , however if this is then nitrified, acidification will occur as the reverse occurs and H + ions are released. The degree of nitrification will depend on the initial soil pH, with rates being highest in less acid soils. • Nitrate leaching may not be a problem for the woodland as such, but it does present a threat to water systems, and is one of the more robust indicators that the system is N saturated. • N affects the composition of leaf litter through changes in species composition and changes in leaf litter chemistry. Cellulose activity may be stimulated. The level of lignins and phenol compounds which can restrict fungal activity and the activity of phenol oxidase often goes down, leading to increased rates of decomposition. Overall mineralisation tends to be increased by N deposition, potentially increasing nutrient availability.

Soil fauna • There have been few studies in this area, but most report negative effects, e.g .on fungal feeders (less mycorrhizal hyphae). • Changes in acidity will also have implications for soil fauna.

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Overview: evidence, processes and main impacts

N deposition is not believed to have a direct, major effect on tree growth in the UK. BUT as illustrated above its indirect effects are many and varied: N can affect woodlands through eutrophication and acidification and these changes are likely to predispose woodlands to these more highly deleterious indirect effects. Woodlands are complex ecosystems, comprising various compartments with different sensitivities to N. The key component are the trees, but in many woodlands there is an under storey of woody shrubs, forbs and grasses and below this, lower plants (cryptograms) carpeting the forest floor. Seasonally, sporocarps, fruiting bodies may appear and below ground there will be a diverse array of mycorrhizal fungi associated with plant roots which are especially sensitive to N deposition. In addition the trees may support epiphytic communities of bryophytes and algae. Thus woodlands, and the different vegetation types they comprise, provide a diverse habitat for wildlife, especially insects, birds and small mammals. N deposition can compromise this biodiversity or conservation value through changes in cover (protection), food type, quantity and quality, changes in the overall environment for predators, and timing of food source availability via effects on phenology (bud burst, bud set, flowering).

Woodlands provide a rough surface and tend to intercept larger amounts of both dry deposited N and orographic deposition than less rough surfaces, e.g. grasslands. This is particularly the case for woodland edges, which experience the highest N deposition, especially where there is a local sourceof gaseous N, e.g. roads and / or intensive agricultural areas. Thus there is often a gradient of N deposition declining from the woodland edge. Generally the members of the lower plant compartment show the greatest sensitivity and the critical load will have been set lower to protect them where these make up a key component of the woodland type. In addition the critical load takes into account changes in soil chemistry associated with acidification and eutrophication which can lead to N leakage, either though leaching (nitrate) or emissions of the greenhouse gases NO or N 2O.

Effects of N deposition can be both direct and indirect, and some are not easily distinguished from issues concerned with management, especially where this involves changing light levels e.g. thinning. Inappropriate or insufficient management and wind throw can simulate N effects and may result in very similar outcomes to N eutrophication, e.g. enhancing grass growth.

Pollutant deposition type and risk areas

Woodlands surrounded by farmland and roads are most at risk from N eutrophication and invasion by ‘casual’ plants because of the greater availability of a seed source for such plants, compared to remote areas surrounded by more semi-natural habitats. Woodlands near intensive livestock units are particularly at risk from ammonia deposition, especially those growing on acid soils, which can be toxic to trees, ground flora and especially epiphytes (Krupa 2003).

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Type of N Form of N Risk areas deposition

Dry NH 3 Woodlands in rural areas with elevated deposition background concentration. Higher dry Gaseous deposition is found close to point sources e.g. intensive livestock units. NOx Woodlands close to combustion plants, and major roads and urban areas. Wet Ammonium, The few woodlands at high altitudes will see + deposition (NH 4 ) orographic enhancement (larger volumes but - precipitation Nitrate, (NO 3 lower concentrations) and occult deposition and occult ) (higher concentrations) (cloud, mist) in varying proportions

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ANNEX B: DETAILS OF HABITAT AND SPECIES SENSITIVITY TO NUTRIENT NITROGEN FOR IDENTIFIED MADINGLEY WOOD - APIS 11

Broadleaved mixed and yew woodland

NVC Habitat sensitive Relevant Nitrogen Empirical Critical Uncertainty in EUNIS Exceedance Code to Nitrogen? Critical Load Class Load kg N/ha/yr these values? ecosystem Impacts class

W8 Yes Meso- and eutrophic 15 - 20 expert judgement G1.A Changes in ground Quercus woodland vegetation

11 Air Pollution Information System - www.apis.ac.uk

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ANNEX C: IDENTIFIED CRITICAL LOADS FOR POTETIALLY AFFECTED SSSI - APIS 12

12 Air Pollution Information System - www.apis.ac.uk

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Appendix C ADMS - Time Variation Hourly Factors

Time Variation Hourly Factors