Medway Valley Countryside Partnership. Medway Catchment and River Cray Giant Hogweed and Non Native Flora Control Programme.

Transcription

1 Medway Valley Countryside Partnership Medway Catchment and River Cray Giant Hogweed and Non Native Flora Control Programme 2011 Report Andrea Griffiths (BSc Hons) Partnership Officer Medway Valley Countryside Partnership Yalding Parish Council 1

2 Contents: 1.1 Introduction Pg Project Overview 2010 Pgs River system reports Pg River Medway Pgs Floating Pennywort Pg Gibbs Brook Pgs Teise and Lesser Teise Pgs River Beult SSSI Pgs River Cray and River Shuttle Pgs Volunteer Involvement Pgs Finance Pg Future Recommendations Pgs 22 2

3 1.1: Introduction The giant hogweed (Hereacleum mantegazzianum) (GH) control programme operating in the Medway catchment entered its 12th year of delivery in In addition to the main target species, this project has been extended to include additional Invasive Non Native Species (INNS) with some areas of riparian Japanese knotweed (Fallopia japonica) (JKW) Himalayan balsam (Impatiens gladulifera) (HB) and floating pennywort (FP) addressed. An increase in voluntary time has also been achieved in the last few years and more landowners and areas in the catchment/rivers are included. 1.2: Project Delivery - Overview 2011 As in previous years, in 2011, almost 300 landowners were contacted and communicated with regarding the scheme. Information on four more landowners was obtained in the Lamberhurst area and these have already been contacted about inclusion in 2012 and onwards. This will improve the coverage of treatment on the River Teise in future years. In 2011 the project expanded out of the current catchment area and covered almost 200km of riparian habitat. This addition and project expansion was via the inclusion of the River Cray and River Shuttle in the London Borough of Bexley. In previous years here some INNS control has taken place by North West Kent Countryside Partnership and organisations such as Thames 21, but in 2011 MVCP delivered some giant hogweed control in this location for Bexley Council and for some local landowners. All treatments were carried out, as in previous years, by Brian Thomas of FCS Vegetation Care and Control. Treatment of the majority of giant hogweed plants took place between April and July. Japanese knotweed (JKW) work also continued in some locations in 2011 to continue with work started in the River Beult and Teise area in Large stands of JKW were treated in August 2011 in Lamberhurst and at various properties along the River Teise. Surveying revealed that JKW treatment administered in 2010 had been very successful, with only some follow up treatment required. Some work with Himalayan balsam was also carried out in Advice was given to the Teise Anglers and Owners Association who subsequently carried out a few events themselves to manually remove the HB from parts of the River Teise. In addition, MVCP carried out two HB removal events with volunteers in The Tatt in Yalding. A tributary of the River Cray, the Shuttle was also included with MVCP carrying out treatment of floating pennywort in September This treatment was carried out on Sidcup Golf Course, where FP was spreading across the course lakes and along part of the River Shuttle where it had spread. 3

4 In 2011, the project continued to deliver giant hogweed control in the Medway Catchment but also expanded to address additional INNS across new areas, further protecting the Thames Basin. All areas covered by the scheme were surveyed by MVCP staff, volunteers and/or Brian Thomas/FCS. All the plants surveyed were treated either before or after they were logged on GPS and plotted on ArcGIS software (with the exception of HB which is too numerous to successfully plot on GIS maps). 1.3: River System Reports Giant hogweed in each of the river systems covered by the project, plus Japanese knotweed (along the River Teise) was treated with glyphosate in the spring and summer of This is a spot treatment and therefore does not affect additional flora. Himalayan balsam, in some locations, was removed manually by volunteers. Floating pennywort in the Borough of Bexley was treated with the same herbicide methodology in September. Survey data is given in this report as both co-ordinate table data and via GIS maps. In recent years the surveying methodology has been improved and plant data is now represented via Geographical Information System (GIS) software. In some areas, GH and INNS are abundant and as such the plant count is amalgamated for ease of representation. In 2011 additional improvements have been made so that stand size (number of plants in a given area) data can be expressed in detail for the first time. In previous years only the location information was highlighted on the maps but from 2011 onwards both location and stand size information will be represented via a graduated colour scheme representing stand sizes in increasing ranges. Highlighting the stand size as well as locations via GIS will allow for further analysis of the reduction of INNS in the catchment to be better monitored over time. Please note: Where permission was granted by the landowners, all the plants logged (and highlighted in the following maps and tables) were treated by MVCP contractors. As such approximately 3000 individual giant hogweed plants were treated throughout the Medway Catchment via this MVCP project in

5 1.3.1: The River Medway A large amount of administrative work took place in the Upper Medway area around Withyham in 2010 to increase the number of landowners involved with the scheme and extend the treatment area. An agreement, new for 2010, was made between MVCP and Royal Tunbridge Wells Angling Society (RTWAS) for the treatment of large amounts of Giant Hogweed adjacent to Summerford Farm properties. This new partnership continued into 2011, with landowners being contacted directly by MVCP in 2011 to ensure the riparian area adjacent to seven properties in the Upper Medway continued to be treated. The usual land which is part of Complete Land Management and East Sussex County Council was also treated as standard. Some agricultural land in the area is listed as organic but MVCP were told by CLM that the plants in these locations would also be controlled. This will be monitored. MVCP contractors carried out chemical treatment in the area in May A follow up survey was carried out on the 5 th June to ascertain success and any new growth. Giant hogweed had been much depleted by the 1 st spray but ongoing control in the area is vital due to the extensive seedbank and therefore to safeguard the rest of the River Medway. Figure 1: Map of the Upper Medway area, highlighting the locations and stand sizes of giant hogweed in those locations. Note: Himalayan balsam is not included as it is too extensive throughout and therefore difficult to plot. 5

6 Table 1: X and Y co-ordinates of INNS in the Upper Medway area 2011 X Y Stand Size Notes JKW GH plus a stand of JKW All along north bank - Summerford Farm Properties (By Rd) MVCP received reports of additional GH on land further upstream. This will be investigated in time for 2012 control work as more extensive control by certain landowners is required and will be encouraged. MVCP can offer advice and assistance to landowners who are not directly in the scheme. Treatment of the giant hogweed on the River Medway between Tonbridge and Maidstone was carried out predominately in June Some additional spraying, such as around Porters Lock, was undertaken in July. Surveying of this stretch of the river took place over three sessions. The first section between Tonbridge and Yalding was surveyed on 3 rd June by an MVCP volunteer/student. The second survey session took place on the 6 th June by MVCP between Teston and Allington Lock and the section (in the middle of the river system) between Yalding and Teston was surveyed by the volunteer/student on 10 th June. Additional data from Allington Lock towards Aylesford was compiled by the project contractor and is included in the table of results and on the maps. In addition, in July a Duke of Edinburgh Award expedition did additional surveying for the three target INN species along the Medway from Yalding to Allington (see Section 2 pg 19/20). Figure 2 shows the maps with stands of giant hogweed along the main River Medway. The original co-ordinate data is shown in Table 2. As this data indicates, most of the plants occurring are now individual plants, rather than large stands, although some hotspot areas are still occurring near Teston (although still much reduced compared to previous years) and near Aylesford. 6

7 Figure 2: Map showing locations and stand sizes for giant hogweed plants along the main Medway Navigation to Aylesford in Table 2: X and Y co-ordinates of giant hogweed on the main Medway Navigation 2011 X Y Stand_Size Notes Opposite_bank Very_small The_Lees_Yalding Teston_To_Barming_Bridge_Opposite_bank Opposite_bank Opposite_bank Opposite_bank Across_Both_Banks Across_Both_Banks

8 Barming_Bridge_To_EastFarleigh Land_inc_railway_line Land_mostly_Network_rail_land Land_Near_Riverside_Park EastFarleigh_Unicomes_Lane Below_Bydews_Wood Nr_Unicomes_Lane Below_Roseholme Clifford_Way Opposite_Pumping_Station Along_Bank_Below_Castle

9 Kent_Enviropower_Land_nr_flyover Not_sprayed_need_to_ascertain_DTZ_overall_ownership Initial observations indicated that plants on Network Rail land along the Medway Valley Line adjacent to the Medway Navigation did not appear to be treated in However on further investigation it was confirmed that plants were sprayed in spring from the railway line, a practise which is carried out each year. It would appear that perhaps some plants lower down the slopes away from the tracks but still on Network Rail land were missed due to the distance from the lines. As such an agreement between MVCP and Network Rail is being discussed and will hopefully be set up for This agreement will involve the continued spraying of most plants along the line by Network Rail and then any additional plants which can be reached and sprayed by the MVCP contractor from the lower adjacent footpaths will be done by MVCP. Discussions are underway between MVCP and Network Rail about a financial contribution to support this work adjacent to the line. Updates will be given in the 2012 annual report. Plate 1: Giant Hogweed on Network Rail land on the Medway Valley Line adjacent to the River Medway near East Farleigh June

10 Floating pennywort (FP) on the River Medway In September 2011, several patches of floating pennywort (Hydrocotyle ranunculoides) were reported on the Medway by an MVCP River Warden Volunteer. One patch in the Medway had been successfully treated by MVCP in 2009 and in previous years. The reports of FP in this case were new. Following this report, MVCP carried out a survey between Yalding and Shoreham Lock and verified 7 patches of FP in this location. This data can be seen in Figure 3 and Table 3 below. At the time of preparing this report, MVCP is liaising with the E.A about additional funds for treating these patches of FP in 2011 (TBC). Figure 3: Floating Pennywort (FP) locations on the River Medway. Table 3: Floating pennywort locations on the River Medway with patch size data. Grid_Ref X Y Stand_Size Notes TQ_68844_ mx5m TQ_68579_ mx3m TQ_68570_ mx3m TQ_68498_ mx3m TQ_68479_ mx2m Both_Sides_Of_the Bank TQ_68395_ mx3m TQ_69117_ mx3m Several Patches Nr_Little_Venice - Marina 10

11 1.3.2: Gibbs Brook This tributary of the river Eden has been included in the giant hogweed control programme for approximately 6 years. Treatment of GH in the area took place in June Although still abundant in places, eyewitness accounts suggest that the plants have reduced overall and spray times are much reduced from previous years. However 2011 survey data indicates that in some areas, such as near Brook Cottage, the plants may have increased. The landowners here confirmed that they had cleared large areas of bramble and as such the extra light levels may have triggered more plants from the seed bank in this location. Overall the area continues to improve from that of several years ago although there are hotspot areas (such as above the sewage work) which, although improving, will need ongoing treatment for the foreseeable future data can be seen in Figure 4 and Table 4: Figure 4: Map showing coordinates and stand sizes for giant hogweed plants along Gibbs Brook, Surrey in

12 Table 4: X and Y co-ordinates for the Gibbs Brook area Surrey in X Y Stand_Size Notes Both_Sides_Of_River Cottage_Garden Both_Sides_Of_River Both_Sides_Of_River Both_Sides_Of_River Sewage_Works Near_Bypass 1.3.3: The River Teise/Lesser Teise Treatment of giant hogweed on the Teise and Lesser Teise (after the bifurcate) took place in June Issues with accessibility have made surveying the River Teise difficult in previous years and survey data has previously not been sufficient. In 2011, to address this issue and gain a greater degree of information, the contractor obtained location and abundance data at the time of treatment. Due to this cooperation with contractors and landowners, much more information has been obtained in 2011 about the abundance of GH along the Teise. For this reason, survey data in extensive compared to that highlighted in previous reports and is split between two area maps in Figure 5 and 6. This data is reiterated in Table 5. The data indicates ongoing hotspot areas around Lamberhurst and Horsmonden as well as near Beltring/Laddingford, but overall the stand sizes have been reduced and most plants are occurring as individuals. On the Lesser Teise some larger stands are still occurring but there occurrence is infrequent. Please note, on the maps, the larger stands occur across the section of bank in question, not specifically in that one GPS spot. 12

13 Figure 5: Map showing location and abundance of GH on the River Teise 2011 from Lamberhurst to Horsmonden. Note: Himalayan balsam is not shown as it is too profuse to plot accurately. 13

14 Figure 6: Map showing location and abundance of GH on the River Teise 2011 from Horsmonden to Laddingford. Map also shows the Lesser Teise and River Beult SSSI. Table 5: X and Y co-ordinates for River Teise and Lesser Teise X Y Stand_Size Notes Hotspot_Upstream_of_Lamberhurst Across_Both_banks Across_Both_banks Across_Both_banks Lamberhurst_Golf_Course Bad_on_North_Bank Across_Both_banks Across_Both_Banks Across_Both_banks 14

15 Across_Both_banks Across_Both_banks Across_Both_banks Across_Both_banks Along_North_Bank Along_South_Bank Along_North_Bank Along_North_Bank Along_South_Bank Across_Both_banks Across_Both_banks Across_Both_banks North_Bank Across_Both_banks Across_Both_banks Across_Both_banks South_Bank North_Bank Hotspot_South_Bank Across_Both_banks Hotspot_South_Bank North_Bank North_Bank Across_Both_banks Across_Both_banks Across_Both_banks Across_Both_banks Hotspot_Across_Both_banks_LESSER_TEI SE Across_Both_banks_LESSER_TEISE Across_Both_Banks_LESSER_TEISE South_Bank_LESSER_TEISE LESSER_TEISE Hotspot_Very_Bad_LESSER_TEISE East_Bank West_Bank 15

16 1.3.4: River Beult SSSI The lower section of the Beult (below the confluence with the Lesser Teise) is the main area which has Invasive Non Native flora. At present up stream of the confluence there are relatively few invasive plants; the one stand of JKW upstream of this location was treated successfully by MVCP in 2010 and there is no GH or HB above the confluence (although both are frequent below). Above the confluence however there are reported areas of Azolla filiculoides (Water Fern) which MVCP are hoping to investigate and possibly control in future years, pending funding. In recent years a transect of the River Beult near Yalding has been surveyed by MVCP to ascertain the ongoing abundance of the plants along this given section. This survey includes plants in the area known as The Tatt, which has an abundance of Himalayan balsam and giant hogweed and is accessible by the public. In addition MVCP and/or the project contractor record additional data further upstream to just below the confluence. The GIS data is together with the Teise data in Figure 6 (pg 14) and this highlights that GH is occurring mainly as single, but frequent plants near Yalding, however closer to where the Lesser Teise feeds in, stand sizes are greater. The data captured for 2011 as seen in Figure 6 is reiterated in Table 6 below. Table 6: X and Y co-ordinates for giant hogweed on River Beult Note HB in Yalding is not shown due to its abundance. X Y Stand_Size Notes The_Tatt_Yalding South_Bank Hotspot Hotspot Hotspot 16

17 1.3.5 River Cray and River Shuttle London Borough of Bexley With some funding obtained via Bexley Council via the North West Kent Countryside Partnership (NWK), and in order to continue work started and carried forward in previous years by both NWK and Thames 21, MVCP carried out some control of giant hogweed along the River Cray in This work was agreed at short notice in June and so advanced prior planned and landowner liaising was not as thorough as standard. However all of the Bexley Council owned land with prior agreement was treated, including Byways 105 and 106. Additional areas were checked and treated after discussions with some local landowners. Surveying was a combined approach from both the contractors and MVCP/NWK staff. Surveying will assist the dormant period planning and indicates where the priority for landowner information is needed for 2012 and in the future. Figure 7 shows the GIS map of Giant Hogweed location information and stand size data obtained in Table 7 show s the co-ordinates data in table format: Figure 7: Map showing location and abundance of GH on the River Cray

18 Table 7: X and Y co-ordinates for River Cray X Y Stand_Size Notes _Plant _Plants 105_BW _Plants Opposite_Bank_105_BW _Plant _Plants Opposite_Bank_106_BW m2 JKW _Plants 106_BW _Plants 106_BW _Plants _Plant Near_Hall_Place _Plants Bexley_Sand_And_Gravel_Land_ _Plants Stables_and_Clarenden_Mews The River Shuttle was also included in the 2011 INNS control programme with some Floating Pennywort control on the adjacent Sidcup Golf Course. FP has been treated previously by NWK but FP has again colonised the golf course lakes and as such threatens the River Shuttle. In order to gain control of this, FP was treated in the source golf course lakes in September Ongoing treatment of FP, when needed is planned for the future, pending ongoing project funding and landowner/leaseholder consent. Further surveying of the River Shuttle for INNS is required. Figure 8 highlights the areas of Giant Hogweed and the areas of FP in the golf course in Figure 8: Map showing location and abundance of GH on the River Cray

19 2.0 Volunteer Involvement: In 2011 there was a greater involvement of volunteers on the project. In previous years volunteers have been involved in surveying but in 2011, with the increase of Himalayan balsam control in certain locations, volunteer involvement was again increased both with surveying and via direct plant removal. In May and July two sessions of Himalayan balsam control were carried out at The Tatt near Yalding, to manually remove the plants. Each of these sessions was a few hours in duration and had approximately 4 volunteers in attendance. Plate 2 and 3: MVCP HB removal in Yalding with volunteers 2011 MVCP also provided advice to a local angling association who then carried out their own control of HB in their location patch. In addition to direct removal of the plants, one Volunteer/student was involved in surveying the River Medway for INNS over 2 sessions, equalling around 12 hours of volunteering. The River Medway was then surveyed again by a group of volunteers from the Waterlooville District Explorer Scouts who were involved in their Bronze Duke of Edinburgh Award. This young group spent 2 full days on the river surveying for MVCP s three main target plants, giant hogweed, Himalayan balsam and Japanese knotweed. There were 6 Explorer Scouts in the expedition team (See Plates 4 and 5, pg 20), aged between 14 and 15. They spent 6 hours on each day journeying and recording the data. This involvement equals 72 man-hours of volunteering on the project. 19

20 Plate 4 and 5: Waterlooville District Explorer Scouts Bronze Duke of Edinburgh Award Surveying for INNS for MVCP 2011 (Courtesy of Ian Nunn) Although not displayed in the maps due to the abundance of HB, the additional data obtained by the Waterlooville District Explorer Scouts on HB and JKW especially will be vital in prioritizing and planning future work. With the HB control and surveying, the number of volunteers hours spent on the project in 2011 was approximately 107 hours overall. The recent reports (Sept 2011) of floating pennywort on the River Medway were made initially by an MVCP River Warden volunteer. This is evidence that MVCP s volunteer programmes link directly to the INNS project and are a valuable addition to the project, offering valuable insight and assistance. 20

21 3.0 Finance: Project finance information has been sent to current funders and partners of the project. If you would like to see this information please contact MVCP. 21

22 4.0 Future Recommendations. MVCP are hoping to continue with the giant hogweed project into the foreseeable future to ensure that the successes of the project continue and that the large abundance of giant hogweed still in the catchment does not spread further. The seed bank from decades of untreated giant hogweed and the size of the catchment area being covered means that control work is still required and will need to be carried out for several years to come. MVCP are working very hard to ensure the best results from the project and as such plan, if adequate funding can be sourced, to better address the additional issues around INNS in the catchment. For example, treatment for INNS can often leave areas of bare ground which are potentially vulnerable from further colonisation of invasive species. As such MVCP would like to supply native grass seed mixes to consenting landowners, so these can be sown following INNS control. In this way, habitat fragmentation issues are addressed and further INNS such as HB in the catchment are less likely to colonise. In addition, MVCP would like to continue to address additional INNS. This has commenced in recent years, as this 2011 report highlights, and MVCP wish to expand on this to better address INNS catchment wide. Himalayan balsam is extremely invasive in parts of the catchment and has outcompeted other species in these areas, as such, in certain hotspot and publically accessible locations, MVCP would like to carry out more HB removal in 2012 and beyond. This will also increase the amount of volunteering and community engagement which is achieved via the project and further assist with public awareness raising. In addition, MVCP has learnt that stands of JKW on the River Medway are spreading. Root fragments from several large stands upstream have been carried down stream and there are now a lot more plants getting established. Both from ecological and economical view points, funding is required to address this situation soon before it worsens. In addition following landowner communications with MVCP, the partnership realises the need to include additional tributaries within the catchment to better protect the vulnerable river systems. For example Hammer Stream, a tributary of the River Beult SSSI, has large areas of HB which are currently affecting farmers and going largely unchecked. Hammer Stream as such could affect the currently INNS free section of the upper Beult if not addressed. Additional surveying of minor tributaries such as the River Sherway would also be advantageous for future priority planning. Although the project has been a success at reducing the areas of hotspot giant hogweed, there is still much to do, both in controlling giant hogweed and addressing other INNS in the catchment. With climate change and other habitat issues in the catchment ongoing INNS control will better protect our native species from further fragmentation and reduction. Ongoing work, and as such funding, is vital to ensure that the hard work achieved across the years is not reversed. 22

23 Andrea Griffiths (BSc Hons) Partnership Officer Medway Valley Countryside Partnership 3 Lock Cottages Lock Lane Sandling Kent ME14 3AU andrea.griffiths@kent.gov.uk