A Survey for Geyer’s Whorl Snail Vertigo geyeri on Cors Erddreiniog SSSI and Cors Geirch SSSI (2016)

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A survey for Geyer's Whorl Snail Vertigo geyeri on Cors Erddreiniog Site of Special Scientific Interest (SSSI)/ National Nature Reserve (NNR) and Cors Geirch SSSI/NNR in October 2016 failed to locate the snail. Survey locations were based upon previous records dating from 1985 to 2007 on Cors Erddreiniog and 1996 and 2008 on Cors Geirch. Losses from some former strongholds on Cors Erddreiniog are probably due to a lack of grazing, leading to the development of blanketing tussocks of Black Bog-rush Schoenus nigricans and Blunt-flowered Rush Juncus subnodulosus which have shaded out the open 'Carex-lawn' habitat required by the snail. This is most pronounced on Nant Isaf spring field (Compartment 13c) which has not been grazed for over 20 months. In other compartments, snail loss may be a consequence of over-grazing, or periods of under-grazing followed by cattle poaching of the remaining open areas. Similarly, Vertigo geyeri losses from known locations on Cors Geirch appear to be due to the development of a rank 'tussocky' sward that has reduced or eliminated the lightly-grazed 'Carex-lawn' habitat as a result of under-grazing. Voucher specimens from 2005 have been confirmed by the author of this report but no vouchers of the four specimens recorded in 2008 have been seen. As small populations of Vertigo geyeri can be easily overlooked, it is premature to declare the snail as extinct on Cors Erddreiniog and Cors Geirch. Additionally, areas which previously supported very small numbers of snails and not sampled in 2016 need to be surveyed soon. More regular surveys are required in order to advise on appropriate grazing regimes if Vertigo geyeri is found to be 'hanging on' on either site. If this is the case, then the development of simplified and affordable surveillance routines is suggested. Even in the apparent absence of Vertigo geyeri, it is vital that areas which previously supported the snail are managed appropriately. Grazing should be re-instated on Nant Isaf spring field as a matter of great urgency, and the current over-grazing of Compartment 9 on Cors Erddreiniog should be relaxed. On Cors Geirch, the area where Vertigo geyeri was first found in 1996 and again in 1998 and 2005 is too rank and grazing levels need to be increased to open up the seepages and the general sward.

Identification

Dynodydd
Identifier
NRW_DS118724
Teitl Amgen
Alternative Title
  • Arolwg o Falwen Droellog Geyer Vertigo geyeri ar SoDdGA Cors Erddreiniog a SoDdGA Cors Geirch (2016)
Laith Metadata
Metadata Language
English
Lineage

Surveys were by the collection of samples of suitable vegetation for drying and seiving.
Additional Information

Willing, MJ., (2017), A survey for Geyer’s Whorl Snail Vertigo geyeri on Cors Erddreiniog SSSI and Cors Geirch SSSI in 2016, NRW Evidence Report No. 209, 47pp., Natural Resource Wales, Bangor.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2017-03-31
Perchennog
Owner
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  Willing
c/o Natural Resources Wales, Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW
http://naturalresourceswales.gov.uk
 

Extent

Extent

Hyd
Geographic Extent
SIR YNYS MON - ISLE OF ANGLESEY
Hyd
Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 
 

Distribution

Dosbarthiad
Distribution

Fformat - Math a Disgrifiad
Format Type and Description
  • Database ()

    Specification

    [A] The final report in Microsoft Word and Adobe PDF formats. [B] Species records, which are held on the NRW Recorder 6 database.

Lleolwr Adnoddau
Resource Locator
Data Download

World Wide Web page

 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
Conformity
Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Explanation
Degree
false
Lineage

Surveys were by the collection of samples of suitable vegetation for drying and seiving.
 

Keywords

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Allweddair
Keywords

NRW Thesaurus
  • vertigo geyeri
  • geyer's whorl snail
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2023-12-31
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

NRW Related Title

A survey of Geyer's Whorl snail Vertigo geyeri on Cors Erddreiniog SSSI and Cors Geirch SSSI in 2016
 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
 

Use Constraints

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

© CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose.
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313138373234 XML
Laith Metadata
Metadata Language
English
Parent Identifier
Welsh Invertebrate Database (WID)

NRW_DS23774
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2024-05-31T09:40:54.748Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
pointOfContact
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

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