Editing Holkham National Nature Reserve

{{short description|Nature reserve in the United Kingdom}}
{{about|the National Nature Reserve of Holkham||Holkham (disambiguation)}}
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| name            = Holkham
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| photo           = Holkham beach from Holkham Meals - geograph.org.uk - 97299.jpg
| photo_caption   = Beach viewed from board-walk through the pines
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| map_caption     = Holkham NNR shown within [[Norfolk]]
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'''Holkham National Nature Reserve''' is England's largest [[national nature reserve (United Kingdom)|national nature reserve]] (NNR). It is on the [[Norfolk]] coast between [[Burnham Overy|Burnham Overy Staithe]] and [[Blakeney, Norfolk|Blakeney]], and is managed by [[Natural England]] with the cooperation of the [[Holkham Estate]]. Its {{convert|3900|ha|acre}} comprise a wide range of [[habitat]]s, including [[grazing marsh]], woodland, [[salt marsh]], [[sand dunes]] and [[intertidal zone|foreshore]]. The reserve is part of the [[North Norfolk Coast Site of Special Scientific Interest]], and the larger area is additionally protected through [[Natura 2000]], [[Special Protection Area]] (SPA) and [[Ramsar Convention|Ramsar]] listings, and is part of both an [[Area of Outstanding Natural Beauty]] (AONB) and a [[World Network of Biosphere Reserves|World Biosphere Reserve]]. Holkham NNR is important for its wintering [[Anatidae|wildfowl]], especially [[pink-footed goose|pink-footed geese]], [[Eurasian wigeon]] and [[brant goose|brant geese]], but it also has breeding [[wader]]s, and attracts many [[bird migration|migrating birds]] in autumn. Many scarce [[invertebrate]]s and plants can be found in the dunes, and the reserve is one of the only two sites in the UK to have an [[Euroleon nostras|antlion]] colony.

This stretch of coast originally consisted of salt marshes protected from the sea by ridges of [[shingle beach|shingle]] and sand, and [[Holkham Camp|Holkham's Iron Age fort]] stood at the end of a sandy spit surrounded by the tidal wetland. The [[Vikings]] navigated the creeks to establish [[Holkham]] village, but access to the former harbour was stopped by drainage and reclamation of the marshes between the coast and the shingle ridge which started in the 17th century, and was completed in 1859. The Holkham estate has been owned by the Coke family, later [[Earl of Leicester|Earls of Leicester]] since 1609, and their seat at [[Holkham Hall]] is opposite the reserve's Lady Anne's Drive entrance. The [[Thomas Coke, 3rd Earl of Leicester|3rd Earl]] planted pines on the dunes to protect the pastures reclaimed by his predecessors from wind-blown sand. The national nature reserve was created in 1967 from {{convert|1700|ha|acre}} of the Holkham Estate and {{convert|2200|ha|acre}} of foreshore belonging to the [[Crown Estate|Crown]].

The reserve has over 100,000 visitors a year, including [[birdwatching|birdwatchers]] and horse riders, and is therefore significant for the local economy. The NNR has taken steps to control entry to the fragile dunes and other areas important for their animals or plants because of the damage to sensitive habitats that could be caused by unrestricted access. The dunes are an essential natural defence against the projected rises in sea level along this vulnerable coast.

== Description ==
[[File:Holkhammapcapped.jpg|thumb|400px|Publicly accessible part of the NNR:
{{image key
|{{Legend|#FFFFFF|Pasture and dunes}}
|{{Legend|#009A00|Pines}}
|{{Legend|#FFCC67|Tidal foreshore and salt marsh}}
|{{Legend|#8516B7|Roads and car parks}}
|{{Legend|#FC0002|Bird hides}}
|'''SHI''': [[Scolt Head Island]] NNR
|'''HB''': Holkham Bay
|'''WS''': Wells [[salt marshes]] (part of Holkham NNR)
}}]]
The reserve lies to the north of the [[A149 road|A149 coast road]], starting just west of [[Burnham Overy|Burnham Overy Staithe]] and extending west past [[Holkham]] to Beach Road, [[Wells-next-the-Sea]]. It also includes the tidal [[salt marshes]] continuing further east to [[Blakeney, Norfolk|Blakeney]].<ref name= holkham17>[[Natural England]] (2009) pp. 17–19.</ref> Its total area of about {{convert|3900|ha|acre}} makes it the largest NNR in England.<ref name= allen148/> The reserve can be accessed by footpaths from Wells and the local villages<ref name=holkhamestateexploren>{{cite web | title= Exploring the National Nature Reserve | url= http://www.holkham.co.uk/naturereserve/explore.html | publisher= Holkham Estate | url-status=dead | archive-url= https://web.archive.org/web/20121215095452/http://www.holkham.co.uk/naturereserve/explore.html | archive-date= 2012-12-15 }} Retrieved 3 September 2012.</ref> including the [[Peddars Way|Peddars Way/Norfolk Coast]] [[long-distance trail]] that traverses the main part of the reserve, and [[National Cycle Route 1]] loops through the core of the NNR between Holkham and Wells.<ref name = sustrans>{{cite web | title= Route 1 | work= National Cycle Routes | url= http://www.sustrans.org.uk/what-we-do/national-cycle-network/route-numbering-system/route-1 | publisher= [[Sustrans]] | access-date= 2012-09-03 | archive-url= https://web.archive.org/web/20120920235702/http://www.sustrans.org.uk/what-we-do/national-cycle-network/route-numbering-system/route-1 | archive-date= 2012-09-20 | url-status= dead }} Retrieved 3 September 2012.</ref> There is a car park near Holkham village at the north end of Lady Anne's Drive that gives access to two [[bird hide]]s, and another parking area at the end of Beach Road in Wells. To the east of the Wells Channel, the reserve is mainly salt marshes and [[mud flats]], and is difficult and potentially dangerous to access, although a public footpath runs along the southern edge of these tidal areas.<ref name = holkham/><ref name=holkhamestatereach>{{cite web | title= Reaching Holkham | url= http://www.holkham.co.uk/naturereserve/reaching.html | publisher= Holkham Estate | url-status=dead | archive-url= https://web.archive.org/web/20121215100243/http://www.holkham.co.uk/naturereserve/reaching.html | archive-date= 2012-12-15 }} Retrieved 3 September 2012.</ref>

The [[salt marsh]]es on this coast are stated in the [[Site of Special Scientific Interest]] (SSSI) notification document to be "among the best in Europe&nbsp;...&nbsp;the flora is exceptionally diverse". Holkham also has good examples of [[dune|sand dunes]], and the [[pine]]s planted on the dunes have provided shelter for other trees and shrubs to become established, making this the only substantial area of woodland in the North Norfolk Coast SSSI.<ref name = encitation/> The dunes are created and altered by the elements, and the sand islands in Holkham Bay have formed only within the last 60 years.<ref name = holkham/> The flat ground inland from the dunes is a reclaimed salt marsh that was used as [[pasture]] until the 1940s, but converted to [[arable land]] during [[World War II]]. The value of the fields to wildlife was reduced by the resulting lower [[water table]], but [[Natural England]]'s management measures have raised the water levels, attracting breeding and wintering birds.<ref name = holkham/> Water management can also be used to ensure a high water table in summer, benefiting breeding waders, and drier conditions in winter, preferred by the geese.<ref name=vickery>{{cite journal | last= Vickery | first= J A | author2=Sutherland, W J| author3=O'Brien, M| author4=Watkinson, A R| author5=Yallop A | year=1997 | title= Managing coastal grazing marshes for breeding waders and overwintering geese: Is there a conflict? | journal= [[Biological Conservation (journal)|Biological Conservation]] | volume= 79 | issue =1 | pages= 23–24 | doi = 10.1016/S0006-3207(96)00111-5 }}</ref> The management of water levels and grassland increased the number of breeding wetland birds from 120 pairs of ten species in 1986 to 795 pairs of 26 species in 1994, and the number of wintering birds of four key wildfowl species rose from 1,215 to 17,305 in the decade from 1983/84.<ref name= harold>{{cite journal | last= Harold | first= Ron | year=1994 | title= Holkham grazing marshes N.N.R | journal= Norfolk & Norwich Naturalists Society Transactions | volume= 30 | issue = 2 Supplement: Norfolk Bird & Mammal Report 1993 | pages=123–130 }}</ref>

== History ==

[[File:Holkham iron age fort.jpg|alt= field with raised grass track leading to distant mound|The mound of Holkham fort is visible at the end of the raised track, formerly its only access.|thumb|left]]
Norfolk has a long history of human occupation. Both [[anatomically modern humans|modern]] and [[Neanderthal]] people were present in the area between 100,000 and 10,000&nbsp;years ago, before the last [[glacial period|glaciation]], and humans returned as the ice retreated northwards. The archaeological record is poor until about 20,000 years ago, partly because of the then prevailing very cold conditions, but also because the coastline was much further north than at present. As the ice retreated during the [[Mesolithic]] (10,000–5,000&nbsp;BCE), the [[sea level]] rose, filling what is now the [[North Sea]]. This brought the Norfolk coastline much closer to its present line, so that many ancient sites are now under the sea in an area now known as [[Doggerland]].<ref name = coles>{{cite web| author = Coles, Bryony | title= The Doggerland project | work= Research projects | url= http://humanities.exeter.ac.uk/archaeology/research/projects/title_89282_en.html | publisher= University of Exeter }} Retrieved 18 September 2012.</ref><ref name= NAE9>Robertson ''et al.'' (2005) pp. 9–22.</ref>

The coast at Holkham originally consisted of salt marshes protected from the sea by ridges of [[shingle beach|shingle]] and sand.<ref name=holkhamestatemain>{{cite web| title= Welcome to Holkham| url= http://www.holkham.co.uk/naturereserve/index.html| publisher= Holkham Estate| url-status=dead| archive-url= https://web.archive.org/web/20070804030404/http://www.holkham.co.uk/naturereserve/index.html| archive-date= 2007-08-04}} Retrieved 2 September 2012.</ref>
A large Iron Age fort ([[Holkham Camp]]) at the end of a sandy spit in the marshes could only be approached along the spit; it enclosed {{convert|2.5|ha|acre}} and remained in use until the defeat of the [[Iceni]] in 47&nbsp;AD.<ref name = ironagefort>{{NHLE| desc= Iron Age fort 900m north east of Dale Hole Cottage | num=1018014 | access-date= 20 August 2012}}</ref> The [[Vikings]] navigated the tidal creeks to establish Holkham, the name deriving from the Danish for "ship town".<ref name = holkhamestatemain/>

The Holkham Estate has been owned by the Coke family since 1609, and [[Holkham Hall]], built by [[Thomas Coke, 1st Earl of Leicester (fifth creation)|Thomas Coke, 1st Earl of Leicester]] between 1734 and 1764, is opposite the NNR entrance.<ref name=holkhamhall>{{cite web|title=History |work=Visitor information |url=http://www.holkham.co.uk/html/history.html |publisher=Holkham Estate |url-status=dead |archive-url=https://web.archive.org/web/20120212231555/http://www.holkham.co.uk/html/history.html |archive-date=2012-02-12 }} Retrieved 2 September 2012.</ref> Until the 17th century, ships could navigate the tidal creeks to reach the staithe (harbour) at Holkham village, but local landowners began to reclaim the marshes from 1639, and the final embankment at Wells was constructed by the [[Thomas Coke, 2nd Earl of Leicester|2nd Earl]] in 1859, completing the conversion of about {{convert|800|ha|acre}} to farmland. The [[Thomas Coke, 3rd Earl of Leicester|3rd Earl]] planted [[Pinus nigra|Corsican]], [[Maritime pine|maritime]] and [[Scots pine]]s on the dunes in the late 19th century to shelter the agricultural land from wind-blown sand,<ref name = holkham/><ref name = holkhamestatemain/> which is carried inland when the wind speed exceeds {{convert|3|m/s|ft/s|spell=in}} and blows from directions between northwest to northeast.<ref name= Oronsaye>{{cite journal | last= Oronsaye | first= W I | title=  Wind action and sand movement near Holkham Bay, North Norfolk Coast, England | journal= Environmental Geology and Water Sciences | volume= 15 | issue = 2 | pages= 77–82 | doi =  10.1007/bf01705094| year= 1990 | bibcode= 1990EnGeo..15...77O | s2cid= 129031049 }}</ref>

The Holkham National Nature Reserve was created in 1967 from {{convert|1700|ha|acre}} of the Holkham Estate and {{convert|2200|ha|acre}} of intertidal sand and mud flats belonging to the [[Crown Estate]].<ref name= allen148>Allen & Pye (1992) p. 148.</ref> In 1986 the NNR was subsumed into the newly created {{convert|7700|ha|acre}} North Norfolk Coast SSSI. The larger area is now additionally protected through [[Natura 2000]], [[Special Protection Area]] (SPA) and [[Ramsar Convention|Ramsar]] listings, and is part of the [[Norfolk Coast AONB|Norfolk Coast Area of Outstanding Natural Beauty]].<ref name=encitation>{{cite web |title=North Norfolk Coast |work=SSSI citations |url=http://www.english-nature.org.uk/citation/citation_photo/1001342.pdf |publisher=Natural England |url-status=dead |archive-url=https://web.archive.org/web/20140202212559/http://www.english-nature.org.uk/citation/citation_photo/1001342.pdf |archive-date=2014-02-02 }} Retrieved 8 November 2011.</ref> The coast from Holkham NNR to [[Salthouse]], together with [[Scolt Head Island]], is a [[World Network of Biosphere Reserves|Biosphere Reserve]].<ref name =liley4>Liley (2008) pp. 4–6.</ref>

== Flora and fauna ==

=== Birds ===

[[File:Geese at dawn - geograph.org.uk - 599662.jpg|alt=flock of geese rising from fields|[[Pink-footed goose|Pink-footed geese]] leaving the grazing marshes at dawn|thumb]]
As many as 50,000 [[pink-footed goose|pink-footed geese]], 13,000 [[Eurasian wigeon]] and 7,000 [[brant goose|Brent geese]] winter at Holkham, making it of international importance for these species.<ref name= holkham/> Up to 400 [[greater white-fronted goose|white-fronted geese]] and a few [[tundra bean goose|tundra bean geese]] may join the wildfowl flocks, and the odd [[peregrine falcon]], [[short-eared owl]], [[merlin (bird)|merlin]], [[western marsh harrier|marsh harrier]] or [[hen harrier]] may hunt over the fields.<ref name = harrup/> The shingle banks and foreshore hold wintering flocks of [[horned lark|shore larks]], [[snow bunting]]s and [[twite]],<ref name= encitation/> and [[wader]]s like [[red knot|knots]], [[Eurasian curlew|curlew]]s, [[dunlin]]s and [[grey plover]] probe for [[invertebrate]]s in the mud flats.<ref name= holkham/>

Spring [[bird migration|migration]] is relatively quiet, although sightings of [[ring ouzel]] and [[common firecrest|firecrest]] are possible amongst the more common arrivals. Breeding birds include [[northern lapwing|lapwings]], [[common snipe]], [[pied avocet]]s, [[common redshank]]s and marsh harriers on the grazing marshes, [[common ringed plover|ringed plovers]] and [[little tern]]s on the beach, and [[black-headed gull|black-headed]], [[European herring gull|herring]] and [[lesser black-backed gull]]s on the salt marsh. The small [[grey heron]] colony has been joined by [[little egret]]s,<ref name = harrup/> and, from 2010, by [[Eurasian spoonbill]]s.<ref name=spoonbill>{{cite web|author=Natural England |title=Breeding spoonbills return to Holkham |url=http://www.birdguides.com/webzine/article.asp?a=2889<!--originally from http://www.naturalengland.org.uk/about_us/news/2011/120911.aspx--> |publisher=BirdGuides}} Retrieved 13 April 2017.</ref> In 2020, a pair of [[Western cattle egret|cattle egrets]] successfully bred at the site, the first time the species had successfully bred in Norfolk.<ref>{{cite web |title=Western Cattle Egret breeds in Norfolk for first time |url=https://www.birdguides.com/news/western-cattle-egret-breeds-in-norfolk-for-first-time/ |publisher=Birdguides |access-date=13 July 2020}}</ref> The pines may occasionally have nesting [[Eurasian siskin|siskins]] or [[common crossbill]]s, and [[parrot crossbill]]s bred in 1984 and 1985.<ref name = harrup/>

Holkham's north-facing coastal location can attract large numbers of migrating birds in autumn if the weather conditions are right,<ref>Elkins (1988) pp. 136–137.</ref><ref>Newton (2010) pp. 97–98.</ref> especially with north to north-east wind.<ref name = harrup/> The common species may be accompanied by a [[wryneck]], [[red-backed shrike]] or [[greenish warbler]] in August, with [[goldcrest]]s, [[thrush (bird)|thrushes]] and [[finch]]es later in the season, and perhaps [[red-breasted flycatcher]]s and [[yellow-browed warbler]]s. [[vagrancy (biology)|Vagrant]] rarities such as [[Pallas's leaf warbler|Pallas's]], [[Radde's warbler|Radde's]] or [[dusky warbler]]s may occur;<ref name = harrup/><ref>Newton (2010) p. 50.</ref> a [[red-breasted nuthatch]] in 1989 was the first, and, as of 2019, the only individual of its species to be recorded in the UK.<ref name= BB1995>{{cite journal | last= Aley | first= Jean |author2=Aley, Roy | year= 1995 | title= Red-breasted Nuthatch in Norfolk: new to Britain and Ireland | journal= British Birds | volume= 88 | issue = 3 | pages= 150–153 | url = http://www.britishbirds.co.uk/search?model=pdf&id=7786 }}</ref>

=== Other animals and plants ===

[[European hare|Brown hares]] and [[European otter]]s are found all along the north Norfolk coast, but [[red squirrel]]s disappeared from the Holkham pines by 1981.<ref name =encitation/> The rare [[natterjack toad]] breeds at Holkham,<ref name= holkham>Natural England (2009) pp. 7–15.</ref> one of only two sites along this coast,<ref name =encitation/> although the [[common frog]], [[common toad]] and [[viviparous lizard|common lizard]] are widespread in appropriate habitats.<ref name= dear>Norfolk Wildlife Trust (2005) pp. 12–15.</ref>
[[File:Saltmarsh at Holkham Bay - geograph.org.uk - 793497.jpg|thumb|alt= marsh with pine trees in the background|The pines and salt marsh protect and stabilise the dunes.|left]]
The [[green hairstreak]], [[purple hairstreak]], [[Polygonia c-album|comma]], [[hummingbird hawk-moth]], [[Hemaris fuciformis|broad-bordered bee hawk-moth]] and [[ghost moth]] are sometimes seen in the woods with the common butterfly and moth species, and a [[Colias croceus|clouded yellow]] or [[Nymphalis antiopa|Camberwell beauty]] may also occur in some years.<ref name = holkpines/> [[Grayling (butterfly)|Grayling]], [[small heath (butterfly)|small heath]] and [[common blue]] butterflies can be found in the dunes,<ref name = holhdunes/> where there is also a large [[Euroleon nostras|antlion]] colony, making Holkham one of only two locations for this predatory insect in the UK.<ref name=antlion>{{cite web| title= Thriving colonies of antlions discovered in Norfolk nature reserve| work= News| date= 17 October 2011| url= http://www.naturalengland.org.uk/about_us/news/2011/171011.aspx| publisher= Natural England| url-status=dead| archive-url= https://web.archive.org/web/20120108095802/http://www.naturalengland.org.uk/about_us/news/2011/171011.aspx| archive-date= 8 January 2012}} Retrieved 7 September 2012.</ref> [[Dragonfly|Dragonflies]] include the [[migrant hawker]], [[southern hawker]] and [[ruddy darter]].<ref name=holkpines>{{cite web | title= Pinewoods and scrub | work= Holkham National Nature Reserve | url= http://www.holkham.co.uk/naturereserve/pinewoodsandscrub.html | publisher= Holkham Estate | url-status=dead | archive-url= https://web.archive.org/web/20121215100304/http://www.holkham.co.uk/naturereserve/pinewoodsandscrub.html | archive-date= 2012-12-15 }} Retrieved 21 August 2012.</ref>

On exposed parts of the coast, the mud and sands are scoured by the tides, and have no vegetation except possibly [[algae]] or [[Zostera marina|eelgrass]], but where the shoreline is more protected, internationally important salt marshes can form, with several uncommon species. The salt marsh contains [[Salicornia|glassworts]] and [[Suaeda maritima|annual seablite]] in the most exposed regions,<ref name= holkham/> with a [[ecological succession|succession]] of plants following on as the marsh becomes more established: first [[Aster tripolium|sea aster]], then mainly [[Limonium binervosum|sea lavender]], with [[Halimione portulacoides|sea purslane]] in the creeks and smaller areas of [[Plantago maritima|sea plantain]] and other common marsh plants.<ref name = encitation/> [[Suaeda vera|Scrubby sea-blite]] and [[Limonium bellidifolium|matted sea lavender]] are characteristic plants of the drier upper salt marsh here, although they are uncommon in the UK away from the Norfolk coast.<ref name= holkham/>

Grasses such as [[Agropyron pungens|sea couch grass]] and [[Puccinellia maritima|sea poa grass]] are important in the driest areas of the marshes, and on the coastal dunes, where [[Ammophila arenaria|marram grass]], [[Elymus farctus|sand couch-grass]], [[Leymus arenarius|lyme-grass]] and [[Festuca rubra|red fescue]] help to bind the sand. [[Eryngium maritimum|Sea holly]] and [[Carex arenaria|sand sedge]] are other specialists of this arid habitat, and [[Petalophyllum ralfsii|petalwort]] is a nationally rare [[bryophyte]] found on damper dunes.<ref name=nbp>{{cite web |title=Coastal Sand Dunes – Habitat Action Plan |url=http://www.norfolkbiodiversity.org/actionplans/habitatactionplans/coastalsanddunes.aspx |publisher=Norfolk Biodiversity Partnership |archive-url=https://web.archive.org/web/20121017153216/http://www.norfolkbiodiversity.org/actionplans/habitatactionplans/coastalsanddunes.aspx |archive-date=2012-10-17 |url-status=dead |access-date=2012-09-05 }} Retrieved 22 August 2012.</ref> [[Lotus corniculatus|Bird's-foot trefoil]], [[pyramidal orchid]],<ref name = encitation/> [[Ophrys apifera|bee orchid]], [[Centaurium pulchellum|lesser centaury]] and [[Carlina|carline thistle]] flower on the more stable dunes,<ref name=holhdunes>{{cite web | title= Dunes | work= Holkham National Nature Reserve | url= http://www.holkham.co.uk/naturereserve/dunes.html | publisher= Holkham Estate | url-status=dead | archive-url= https://web.archive.org/web/20121215095447/http://www.holkham.co.uk/naturereserve/dunes.html | archive-date= 2012-12-15 }} Retrieved 18 August 2012.</ref> where the rare [[Helichrysum luteoalbum|Jersey cudweed]] and [[Corynephorus canescens|grey hair-grass]] are also found.<ref name = encitation/> The narrow {{convert|5|km|mi|abbr=on|adj=on}} belt of pines shelters [[Goodyera repens|creeping lady's tresses]] and [[Monotropa hypopitys|yellow bird's nest]].<ref name= holkham/><ref name = harrup>Harrup & Redman (2010) pp. 242–245</ref>

== Recreation ==

[[File:Horses on Holkham beach - geograph.org.uk - 543980.jpg|thumb|alt=horse and rider on a sandy beach|The reserve has many visitors every year, including horse riders on the beach.]]
A 2005 survey at Holkham and five other North Norfolk coastal sites found that 39&nbsp;per cent of visitors gave [[birdwatching]] as the main purpose of their visit. The 7.7&nbsp;million day visitors and 5.5&nbsp;million who made overnight stays in the area in 1999 are estimated to have spent £122&nbsp;million, and created the equivalent of 2,325 full-time jobs. Holkham NNR is one of three sites within the SSSI that attract 100,000 or more visitors annually, the others being [[Titchwell Marsh]] and [[Cley Marshes]].<ref name =liley4/> The large number of visitors at coastal sites sometimes has negative effects. Wildlife may be disturbed, a frequent difficulty for species that breed in exposed areas such as Ringed Plovers and Little Terns, and also for wintering geese. Plants can be trampled, which is a particular problem in sensitive habitats such as dunes and vegetated shingles.<ref name =liley10>Liley (2008) pp. 10–14.</ref> The discovery of the nationally rare [[Geastrum minimum|tiny earthstar]] [[fungus]] at Holkham led its finders to state that "The survival of this species in Britain would undoubtedly benefit from the construction of a boardwalk across this fragile and frequently-visited habitat."<ref name= telfer>{{cite journal | last= Telfer | first= Mark G | author2=Lambdon, Philip W| author3=Gurney, Mark | year=2000 | title= Recent discoveries among the gasteroid fungi of Norfolk | journal= Field Mycology | volume= 1 | issue = 1 | pages= 30–32 | doi =10.1016/S1468-1641(10)60011-4| doi-access= free }}</ref>

The Little Tern colony at Holkham, holding seven per cent of the British population, is cordoned off in the breeding season, with signs explaining why people are excluded from the area. The dune vegetation can be damaged by too many people walking over it, leading to [[Blowout (geology)|blowout]], and the rapid wind erosion of the sand. Boardwalks and steps enable visitors to reach the beach on foot without harming the dunes,<ref name= holkham/> and horse riders and [[naturism|naturists]] are asked to stay on the beach and keep off the dunes.<ref name =nuff>{{cite web| title= Holkham Bay – Norfolk | url= http://nuff.org.uk/east-of-england/134-holkham-bay-norfolk | publisher= Naturist UK Fact File}} Retrieved 5 September 2012.</ref><ref name = Englandtourism>{{cite web| title= Holkham Beach in Norfolk | url=http://www.visitengland.com/ee/idea/Coast/Holkham-Beach.htm | publisher= Visit England}} Retrieved 5 September 2012.</ref><ref name=horse>{{cite web| title =Horse riders| url =http://www.naturalengland.org/Images/HorseridingHolkham_tcm6-19818.pdf| publisher =Natural England| url-status =dead| archive-url =https://www.webcitation.org/6AdtiYxob?url=http://www.naturalengland.org/Images/HorseridingHolkham_tcm6-19818.pdf| archive-date =2012-09-13}} Retrieved 7 September 2012.</ref> As the climate becomes warmer in the future, there is likely to be more tourism pressure on the coasts, but the effects of this may be mitigated by a move towards lower-impact activities like bathing.<ref name= coombes>{{cite journal | last=  Coombes | first= Emma G |author2=Jones, Andy P | year= 2010| title= Assessing the impact of climate change on visitor behaviour and habitat use at the coast: A UK case study | journal= Global Environmental Change | volume= 20 | issue = 2 | pages= 303–313| doi =  10.1016/j.gloenvcha.2009.12.004}}</ref>

The Norfolk Coast Partnership, a grouping of conservation and environmental bodies, divides the coast and its [[hinterland]] into three zones for tourism development purposes. Holkham Dunes, along with [[Holme Dunes]] and [[Blakeney Point]], were considered to be sensitive habitats already suffering from visitor pressure, and were designated as red-zone areas with no development or parking improvements to be recommended. The rest of the NNR is placed in the orange zone, for locations with fragile habitats but less tourism pressure.<ref name= zones>Scott Wilson Ltd (2006) pp. 5–6.</ref>

== Threats ==
[[File:Grey dunes - geograph.org.uk - 733431.jpg|thumb|alt=sand dunes with coarse grass|Vegetated dunes along the coast protect the reserve from flooding.]]
The underlying geology of the North Norfolk coast is [[Cretaceous]] [[chalk]], exposed at [[Hunstanton]] cliffs just to the west of the SSSI, but buried by soft [[Quaternary]] glacial debris for the entire length of the SSSI coast.<ref name= NAE46>Robertson ''et al.'' (2005) p. 46.</ref> Unlike the soft, rapidly eroding cliffs further east,<ref name=nndc>{{cite web |title=Coastal Erosion |work=Coastal Management |url=http://www.northnorfolk.org/coastal/189.asp |publisher=North Norfolk District Council |archive-url=https://web.archive.org/web/20130508193335/http://www.northnorfolk.org/coastal/189.asp |archive-date=8 May 2013 |url-status=live }} Retrieved 19 August 2012.</ref> the coast of the SSSI has shown a less consistent pattern, with a net accretion of beach material between 1880 and 1950.<ref name =may>May, V J (2003) "[http://jncc.defra.gov.uk/pdf/gcrdb/GCRsiteaccount2038.pdf North Norfolk Coast]" in May (2003) pp. 1–19.</ref> However, this coastline is threatened by [[climate change]], with the sea level rising an estimated 1–2&nbsp;mm per year for the last 100 years, increasing the risk of flooding and coastal erosion.<ref name= smp532>East Anglia Coastal Group (2010) pp. 32–33.</ref>

Half the area of the salt marshes that formed in the lee of Scolt Head Island has been reclaimed in the last 300 years, creating ecologically important, but very fragile, grazing marshes. Although Holkham is low-lying and can flood in severe weather conditions, it is protected by the spit that developed at the Holkham Gap in the 1990s and the dunes along the coast, which are increasingly being stabilised by vegetation.<ref name = smp15>East Anglia Coastal Group (2010) pp. 15–18.</ref> The [[Environment Agency]]'s management plan until 2105 is to rely on the natural protection of the dunes, intervening only if work is necessary to maintain their effectiveness in the face of a potential sea level rise of {{convert|1.1|m|ft|abbr=off}} by that date.<ref name = smp15/><ref name = smp80>East Anglia Coastal Group (2010) p. 80.</ref> The shingle that makes up Scolt Head Island is moving westwards and southwards at up to {{convert|3.5|m|ft|abbr=off}} per year. This may affect the movement of [[sediment]], and lead to some erosion of the dunes and beaches at Holkham, but should not destroy their effectiveness as a sea defence unless the island reattaches to the mainland at some date in the distant future.<ref name= smp532/>

== References ==
{{reflist|25em}}

== Cited texts ==
{{refbegin|35em}}
* {{cite book|ref={{sfnref|Allen & Pye|1992|pp=148-168}}|last1=Allen|first1=John R. L. |last2=Pye|first2=Kenneth|title=Saltmarshes: Morphodynamics, Conservation, and Engineering Significance|url=https://books.google.com/books?id=1hrg5UoOtAoC|year=1992|publisher=Cambridge University Press|isbn=978-0-521-41841-6}}
* {{cite book | author = East Anglia Coastal Group | title = North Norfolk shoreline management plan | year =2010 | location = Peterborough | publisher = Environment Agency }}
* {{cite book | last = Elkins | first = Norman | title = Weather and bird behaviour | year =1988 | location = Waterhouses, Staffordshire | publisher = Poyser | isbn =0-85661-051-8 |url=https://books.google.com/books?id=fiQb4GcuDx8C}}
* {{cite book | last = Harrup | first = Simon |author2=Redman, Nigel | title = Where to watch birds in Britain | year = 2010 | location = London | publisher = Christopher Helm | isbn = 978-1-4081-1059-1 |url=https://books.google.com/books?id=ATJLAAAAQBAJ}}
* {{cite book |last=Liley |first=D. |title=Development and the north Norfolk coast. Scoping document on the issues relating to access |year=2008 |location=Wareham, Dorset |publisher=Footprint Ecology |url=http://www.northnorfolk.org/ldf/documents/Development_and_the_North_Norfolk_Coast.pdf |archive-url=https://web.archive.org/web/20120831135810/http://www.northnorfolk.org/ldf/documents/Development_and_the_North_Norfolk_Coast.pdf |archive-date=2012-08-31 |url-status=dead |access-date=2012-09-02 }}
* {{cite book | editor-last = May| editor-first = V. J. | title = Geological Conservation Review: volume 28: Coastal geomorphology of Great Britain | year = 2003 | location = Peterborough | publisher = [[Joint Nature Conservation Committee]] | isbn = 1-86107-484-0|url=https://books.google.com/books?id=RfEjAQAAIAAJ}}
* {{cite book | author= Natural England | title = Holkham National Nature Reserve | year =2009 | location = Sheffield | publisher = Natural England  |id=Catalogue Code: NE167 |url = http://publications.naturalengland.org.uk/file/62094}} (automatic download).
* {{cite book | last = Newton | first = Ian | title = Bird migration: Collins New Naturalist Library (113) | year =2010 | location = London | publisher = Collins| isbn = 978-0-00-730732-6 |url=https://books.google.com/books?id=P6ifQAAACAAJ }}
* {{cite book | author = Norfolk Wildlife Trust | title = NWT Cley and Salthouse Marshes management plan April 2005–March 2010 | year = 2005 | location =Norwich|publisher = Norfolk Wildlife Trust}}
* {{cite book |last=Robertson |first=David |author2=Crawley, Peter |author3=Barker, Adam |author4=Whitmore, Sandrine |title=Norfolk Archaeological Unit Report No. 1045: Norfolk rapid coastal zone archaeological survey |year=2005 |location=Norwich |publisher=Norfolk Archaeological Unit |url=http://www.english-heritage.org.uk/publications/norfolk-rczas/naurpt1045coastalsurvey.pdf |archive-url=https://web.archive.org/web/20110802034950/http://www.english-heritage.org.uk/publications/norfolk-rczas/naurpt1045coastalsurvey.pdf |archive-date=2 August 2011 |url-status=live }}
* {{cite book |author=Scott Wilson Ltd |title=Tourism benefit and impacts analysis in the Norfolk coast Area of Outstanding Natural Beauty |year=2006 |location=Norwich |publisher=Norfolk Coast Partnership |url=http://www.norfolkcoastaonb.org.uk/mediaps/pdfuploads/pd000925.pdf |archive-url=https://web.archive.org/web/20160207060219/http://www.norfolkcoastaonb.org.uk/mediaps/pdfuploads/pd000925.pdf |archive-date=7 February 2016 |url-status=dead }}
* {{Cite web
 |title       = Holkham beach - saved for Naturism by BN
 |author      = Andrew Welch
 |work        = British Naturism
 |date        = 17 September 2014
 |access-date  = 2014-09-18
 |url         = http://www.bn.org.uk/articles.php/_/news/holkham-beach-saved-for-naturism-by-bn-r304
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20141012011439/http://www.bn.org.uk/articles.php/_/news/holkham-beach-saved-for-naturism-by-bn-r304
 |archive-date = 12 October 2014
}}
{{refend}}

== External links ==
*[https://web.archive.org/web/20141215011258/http://www.holkham.co.uk/html/nature_reserve.html Holkham Nature Reserve website]
*[https://web.archive.org/web/20120812022214/http://www.natureonthemap.naturalengland.org.uk/map.aspx?map=nreserves Interactive map] Natural England.
*[https://web.archive.org/web/20131020040428/http://www.birdseyeviewbooks.com/pagesamples/Holkham.pdf Holkham images], including aerial views, Bird's Eye Books.

{{North Norfolk Coast Site of Special Scientific Interest}}

{{featured article}}

[[Category:National nature reserves in England]]
[[Category:Nature reserves in Norfolk]]
[[Category:Nude beaches]]
[[Category:Protected areas established in 1967]]
[[Category:Holkham]]
[[Category:Coastal erosion in the United Kingdom]]