Portfolio https://www.esdm.co.uk/portfolio http://www.rssboard.org/rss-specification mojoPortal Blog Module en-GB 120 no Review of occurrence and options for control of Common Cord-grass in Ireland Exegesis was contracted by the National Parks and Wildlife Service to review the ecology, occurrence and options for control of common cord-grass in Ireland. This work built upon the previous review of common cord-grass we undertook that focused on England. In England the species can be regarded as an endemic native, but in Ireland it is regarded as an invasive non-native.

The distribution of common cord-grass Sporobolus anglicus/Spartina anglica in Ireland.
Common cord-grass. © Tom Haynes.

The objectives of this review were to:

  • Review the ecosystem effects of common cord-grass
  • Map the distribution and extent of common cord-grass in Ireland
  • Review the options for the control and management of common cord-grass
  • Develop a common cord grass control action plan that can be applied to coastal sites in Ireland

Literature review suggested that the perceived impacts of common cord-grass are often speculative. There was evidence of an impact on macrobenthos diversity, which may explain reported impacts on wading birds that feed on these organisms. There is also evidence that it can impact eelgrass Zostera beds. However, few other reported impacts had strong support and there were suggestions that common cord-grass might facilitate other species. There are also uncertainties about the relationship of sediment regimes and common cord-grass, and the potential impact of management and dieback.

Data analysis was undertaken in PostGIS. The extent of common cord-grass was determined based on the two Saltmarsh Monitoring Projects and the SAMFHIRES project. These provided excellent and up to date coverage, suggesting that the extent of common cord-grass was in the range 688 to 1,223 ha. These data combined with presence based records of the species showed that common cord-grass was widely distributed in Ireland, with records intersecting 167 out of 214 coastal sites.

The threat posed by common cord-grass to Annex I habitats was assessed. It was found to pose a substantial threat to three Annex I habitats, with particular concern for the rarest habitat considered (H1420).

Based on the literature review, a mixture of cutting, smothering, excavation and herbicide application could be used to control common cord-grass. However, this came with caveats, as some techniques, such as cutting, are unlikely to be effective on their own, and all techniques risk impacting other species and habitats in the vicinity. We therefore developed a management decision tool to help guide managers though the analysis required to determine the amount of survey and management action required for a site. This was provisionally implemented on the 167 coastal sites with records of common cord-grass to estimate the extent and costs of actions required.

Note that common cord-grass is currently subject to a degree of nomenclatural uncertainty. Formerly known as Spartina anglica, it is now considered to be a member of the genus Sporobolus, as Sporobolus anglicus. However, this change has not been universally accepted.

Further information from Mike Lush.


Mike Lush]]>
https://www.esdm.co.uk/review-of-occurrence-and-options-for-control-of-common-cord-grass-in-ireland https://www.esdm.co.uk/review-of-occurrence-and-options-for-control-of-common-cord-grass-in-ireland https://www.esdm.co.uk/review-of-occurrence-and-options-for-control-of-common-cord-grass-in-ireland Wed, 23 Dec 2020 10:51:00 GMT
Common cord-grass <i>Spartina anglica</i> and its management in estuarine Natura 2000 sites Distribution of common cord-grass Spartina anglica in EnglandCommon cord-grass Spartina anglica is a perennial grass found on mud deposits in saltmarshes. It originated as a hybrid of the native small cord-grass S. maritima and the North American species smooth cord-grass S. alterniflora, but became fertile and subsequently spread across the UK. It is now considered to be an endemic native in the UK, but may be non-native locally where it was planted to support coastal protection and land claim projects. It is also considered to have a detrimental impact on mudflat and saltmarsh biodiversity and processes, but detailed evidence of these impacts is limited.

Exegesis, working in partnership with NatureBureau, were contracted to undertake an EU LIFE+ supported review of S. anglica as part of Natural England's Improvement Programme for England’s Natura 2000 Sites.

S. anglica has been implicated in a number of impacts on saltmarsh habitats, including increased accretion rates, changed to erosion patterns, reductions in eelgrass Zostera beds and glasswort Salicornia communities, and reduction of areas suitable for bird feeding. We conducted a review of these impacts, which led us to conclude that the overall impact of S. anglica could not clearly be regarded as either positive or negative, as it is hard to separate the impacts caused by S. anglica from those resulting from other processes. For example, causal links between S. anglica and reduction in bird feeding areas were not identified. There is also evidence of S. anglica co-dominating with Salicornia in mixed communities where only S. anglica was known previously, possibly due to a decrease in accretion rates.

We collated recent survey data and species records to assess the extent and distribution of S. anglica. Unfortunately, due the limited coverage of recent survey data very few areas of S. anglica dominated communities could be identified, so the estimate of extent was considered to be a gross underestimate. Recommendations were made to gain a more complete knowledge of the extent of S. anglica using remote sensing and field survey. In contrast, data showing the distribution of S. anglica were more readily available than previously, allowing detailed distribution maps to be created. These showed that the distribution of S. anglica appears to have been relatively stable, having changed little since 1970.

We developed a S. anglica monitoring protocol that aimed to collect information that could be used to determine the extent of S. anglica and to help decide whether management was required. Draft survey forms were tested on sites in the Severn Estuary, Essex coast and North Northumberland Coast, following which improvements were made.

A review of S. anglica control techniques was undertaken, covering physical removal, cutting, grazing, smothering, rotoburying, treatment with herbicides and biological control. This allowed the most effective methods of controlling S. anglica to be identified, but it was noted that any control should be undertaken cautiously and based upon sound evidence, as its removal was likely to result in sediment discharge and potential impacts on designated features. A management decision flow chart was created that aims to help managers of Natura 2000 sites decide where management is most appropriate.

Read the report.

We subsequently undertook a similar review of common cord-grass in Ireland.

Further information from Mike Lush.


Mike Lush]]>
https://www.esdm.co.uk/common-cord-grass-ispartina-anglicai-and-its-management-in-estuarine-natura-2000-sites https://www.esdm.co.uk/common-cord-grass-ispartina-anglicai-and-its-management-in-estuarine-natura-2000-sites https://www.esdm.co.uk/common-cord-grass-ispartina-anglicai-and-its-management-in-estuarine-natura-2000-sites Mon, 06 Oct 2014 10:27:00 GMT
Understanding the impact of invasive non-native species on protected sites Invasive non-native species (INNS) are considered the second biggest threat to global biodiversity following habitat loss, causing impacts through consumption, resource competition, introduction of diseases, interbreeding and disturbance. They can have economic, agricultural and health impacts, with an estimated cost to the English economy of at least £1.3 billion per year. They also present a significant risk to the favourable condition of England’s protected sites.

The non-native harvestman Dicranopalpus ramosusExegesis were contracted to investigate the distribution of non-native species on protected sites in England, in order to help develop a programme of work to tackle INNS. This involved:

  • the development of a master list of 3,687 non-native species (NNS)
  • the collation of nearly five million records from the National Biodiversity Network (NBN) Gateway and a range of Natural England and third party datasets
  • spatial analysis of NSS distribution against Special Area of Conservation (SAC), Special Protection Area (SPA) and Site of Special Scientific Interest (SSSI) boundaries in SQL Server

We presented the results in Microsoft Excel workbooks showing the NNS that had been recorded from each site. Each spreadsheet could be filtered, allowing only the data within a specific site or region to be displayed. This showed that 98% of SACs, 99% of SPAs and 87% of SSSIs had records of NNS. Potential INNS intersected with 90% of SACs, 96% of SPAs and 75% of SSSIs.

The results for seven sites were reviewed against on the ground knowledge by Natural England site staff to determine any differences. We also made a comparison against data in Natural England’s ENSIS database. These comparisons demonstrated the case for increasing data flow by increasing awareness.

Based on the results, we undertook a review of the recording, systems and data flow processes within Natural England. We recommended and costed the use of the NBN Gateway as a data repository and the use of existing Natural England systems for recording and interrogating INNS data. Additional recommendations were made to improve data flow more generally.

Read the report.

Further information from Mike Lush.


Mike Lush]]>
https://www.esdm.co.uk/understanding-inns https://www.esdm.co.uk/understanding-inns https://www.esdm.co.uk/understanding-inns Mon, 04 Aug 2014 23:00:00 GMT