NON-NATIVE PLANTS ON SOUTH GEORGIA Season Report 2017/18
NON-NATIVE PLANTS ON SOUTH GEORGIA Season Report 2017/18
Kelvin Floyd Indigena Biosecurity International
This report was prepared by Indigena Biosecurity International Limited for the Government of South Georgia and the South Sandwich Islands
April 2018
PO Box 54, Nelson, New Zealand. www.indigena.co.nz INTRODUCTION
Non-native plant management during the 2017/18 season focused on undertaking actions to implement the ‘South Georgia Non-Native Plant Management Strategy 2016–2020’. Management action was taken to address priority non-native plant species and high priority sites. Further surveys were carried out to fill gaps in distribution data. There are now 81 non-native plant species recorded from South Georgia. Of these, 35 species are historic and presumed extinct, 3 are widespread and naturalised, and 4 are common locally. There are 37 species (Class One) that are managed on a zero population density basis (no plants present each season and aiming for eradication). Two research species require more information to classify. The 2017/18 season appeared to be a particularly good growing year for many species, with grasses setting seed earlier than usual and forming very dense swards, and other previously unknown populations becoming visible. Weather records for the period 1999–2018 confirmed above-average temperatures in late winter and spring, and these would have enabled early growth this season. A small area of a new species for the island (Pernettya pumila) was found near Leith Harbour and is to be formally identified by the Royal Botanical Gardens at Kew.
Non-native plant species classes
Class Description
Class One – Priority species; require species-led control at the island-wide level, to control Species-Led all plants before they reach maturity. All sites with these species have a 'Site Tag' in the Weeds Database, to enable managing follow-up visits.
Class Two – Species of moderate distribution, requiring site-led control. Priority Site-Led populations are those at high-use visitor sites, and sites with small infestations where control will reduce further dispersal.
Class Three – Species which are widespread and abundant, and require management at Site-Led high-use visitor sites and at some remote outlier sites where appropriate.
Research More information required before classification.
Non Native Plants on South Georgia Season Report 2017/18 Page 3 WORK UNDERTAKEN THIS SEASON
This season the field team consisted of Kelvin Floyd (team leader), Sally Poncet, Ken Passfield and Zac Milner. Kelvin, Ken and Sally arrived at King Edward Point on FPV Pharos SG on the 23rd of December and weed control began on the 4th January when Kelvin carried out the first Cardamine glacialis sweep and control of Class Two and Three species around King Edward Point (KEP) and Grytviken. Sally and Ken started work on the 16th January at Prince Olav Harbour whaling station with FPV Pharos SG support, then proceeded to Husvik where they were based ashore at Husvik villa between 18th January and 28th February. They carried out control of Class One species at the three whaling stations and control of Class One and Class Two species in all management units between Leith Harbour and Kelp Point, as well as Carlita, Olsen Valley, Gullbrandsen and a day on Grass Island supported by GSGSSI/BAS jet boats, returning to KEP on 28th February on board MV Hans Hansson. Zac arrived from New Zealand at King Edward Point on board HMS Clyde on the 16th January and worked with Kelvin on the Cardamine glacialis sites as well as Class One and Two control on Thatcher Peninsula and visits to Hound Bay, Luisa Bay, Godhtul and Reindeer Valley (Barff Peninsula) and Greene Peninsula.
Kelvin departed KEP on the 1st March to join the Rat Monitoring Team on MV Hans Hansson, and while landing at sites around the island, surveyed for weeds when possible. 36 previously unsurveyed management units were visited and records added to the database. Zac also departed on the 1st March on the cruise ship National Geographic Orion. Sally and Ken remained at KEP to continue control at Grytviken and at Ocean Harbour (Barff Peninsula). Ken departed on the 10th April on the cruise ship Le Soleal and Sally on the 18th on the cruise ship National Geographic Explorer.
Summary: • 2,833 square metres of Class One species were treated this year compared to 839 square metres last season. Rumex acetosella follow-up accounts for half this number, with the remaining spread across the other species. • 15,112 square metres of Class Two species were treated this season. • 36 additional weed management units were surveyed this season (while part of a rodent monitoring trip) vastly increasing the knowledge of weed distribution across the island. • Pernettya pumila (Falklands mountainberry) was found in the Hansen Valley near Leith Harbour, a first record for the island. Samples have been sent to Kew. • Possibly due to a very warm late winter and spring Cardamine glacialis was found dropping seed a month earlier than ever noted before.
Herbicide usage and species details were recorded daily with all information entered into the South Georgia Plants Database.
Non Native Plants on South Georgia Season Report 2017/18 Page 4 SOUTH GEORGIA NON-NATIVE PLANT STATUS 2017/2018
Species have been classified within the Non-Native Plant Strategy and are separated into each class below with summaries for each species. A full species list is contained at the end of this report.
CLASS ONE SPECIES
Each species summary includes a graph showing total plant coverage treated in square metres for each control season.
Class One locations visited 2017/18
Achillea millefolium yarrow No plants found at the Grytviken or Husvik sites this season. Spread is vegetative as the species is not known to flower or set seed at South Georgia. 25 20 20 20
15
10 Coverage sq m 5 3 1.5 0.08 0.01 0.01 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective.
Non Native Plants on South Georgia Season Report 2017/18 Page 5 Achillea ptarmica sneezewort Plants continue to be found within Husvik whaling station. Stem and root fragments are spread during periods of flooding and have also increased this year due to the favourable growing season and in response to cessation of grazing by reindeer. Spread is vegetative although in favourable seasons (eg this year), some plants will flower.
350 305 300
250
200
150 126
Coverage sq m 100
50 20.5 13.4 11.2 6 0 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective but continued vigilance for new fragments required.
Agrostis stolonifera creeping bent The single site of 200 sq m in Husdal (at Husvik) was controlled this season. Spread is vegetative as the species is not known to flower or set seed at South Georgia. Season Summary: Initial control this season.
Agrostis vinealis brown bent Follow-up on all known sites was undertaken with more outliers identified at known sites (eg Olsen Valley) and treated. Spread is both vegetative and via wind and water-assisted seed dispersal.
350 310.85 300
250 205.61 200
150
Coverage sq m 100
50 23.02 0 10 0.25 0 2010/2011 2011/2012 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control is effective on known sites however new sites are still recovering from grazing.
Non Native Plants on South Georgia Season Report 2017/18 Page 6 Allium schoenoprasum chives Nothing found at the Leith Harbour site this season. Spread is vegetative although the species was occasionally recorded in flower in favourable years. 0.12 0.1 0.1
0.08
0.06
0.04 Coverage sq m
0.02 0 0 0 0 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Likely eradicated but site will still be monitored.
Anthoxanthum odoratum sweet vernal grass Sweet vernal grass occurs at one site on the lower slopes of the Husdal, Husvik. Seedlings continue to be found along with small outliers around the original site. A small area was also found at Grytviken this season. Spread is via wind-assisted seed dispersal.
3500 3010 3000
2500 2001 2000
1500
Coverage sq m 1000
500 118.01 131.1 0 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control appears effective however seedlings keep appearing.
Non Native Plants on South Georgia Season Report 2017/18 Page 7 Anthriscus sylvestris cow parsley The single site of this species is on the northern side of Nybrakka at Grytviken. Plants found were controlled before they flowered and produced seed; however, this site continues to produce seedlings from the original plant’s seedbank.
14 12 12
10
8 6 6
Coverage sq m 4
2 1 0.2 0.5 0.25 0.5 0.05 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 Season Summary: Control effective but persistent seedbank.
Cardamine glacialis bittercress Three sweeps of the bittercress sites were completed this season with 3.93 sq m recorded. However, during the first sweep in early January, it was discovered that some seed pods had developed early and dropped seed. This is a month earlier than previously recorded and it is possible that the very warm winter/spring promoted early development of the plant. The timing of control will need to be adjusted to ensure plants are controlled before releasing seed.
700 616.62 600
500 372.76 400
300
Coverage sq m 200
100 29.32 20.84 17.68 10.63 7.8 3.93 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control on known plants effective with detection of very small adults is an ongoing issue. Also, the major shift is the timing of seed production this season – this has added to the seedbank and timings will need to take this into account.
Capsella bursa-pastoris shepherd's purse Was among bittercress sites at King Edward Point but not seen for many years. Season Summary: Likely eradicated.
Non Native Plants on South Georgia Season Report 2017/18 Page 8 Carex aquatilis water sedge Three juvenile plants were found at the Husvik site this season.
250 200 200
150
100 Coverage sq m 50 8 1 1 0.2 0 0.01 0 2010/2011 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 Season Summary: Control effective although small fragments continue to appear.
Carex nigra common sedge No plants were found this season at the Ocean Harbour or Karrakatta Valley sites. At the Husvik site, last year’s control was ineffective so the site was treated at a higher herbicide rate. 120 100 100
80
60
40 Coverage sq m
20 10 10 5 1 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Herbicide rate altered for remaining site.
Carex sp. sedge species The small patch of Carex species sprayed on the west shore of Block Lake in 2013 was not found this year. Season Summary: Control effective.
Carex vallis-pulchrae marsh sedge This sedge (a new species record for South Georgia) was found at several sites in Hansen Valley inland from the Leith Harbour whaling station in 2016 and identified by Kew in 2017. An area of 50 sq m was sprayed this season. Season Summary: Initial control this season.
Non Native Plants on South Georgia Season Report 2017/18 Page 9 Dactylis glomerata cocksfoot No sign of the single plant controlled in 2010 at Grytviken was found this season. Season Summary: Likely eradicated.
Deschampsia cespitosa tufted hair-grass Previous control has been effective at Ocean Harbour, Grytviken, Husvik, Husdal, Stromness, Pintail Peninsula, Hansen Valley and Leith. However, new mature clumps continue to be found as the seeds continue to germinate and flower heads show themselves above other vegetation; these were all treated. Also, a single mature plant was found on the river flats at Hound Bay, the first record of this species at this site.
160 150
140
120 111.38
100 79.1 85.11 80 60 44.8
Coverage sq m 35 40 25.71 20
0 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective on known plants however new plants continue to be discovered. Although its distribution is larger than thought, plants are highly visible once mature so can be controlled before producing large amounts of seed. All plants now added as waypoints in database to assist follow-up.
Deschampsia flexuosa wavy hair-grass No plants were found at the Maiviken or Karrakatta Valley sites; a small amount of follow- up was required at the Husdal site where a few seedlings had germinated. A single plant was found next to the Sӧrling Valley hut on Barff Peninsula, the first record of this species at this site.
1.2 1 1
0.8
0.6 0.5
0.4 0.3 Coverage sq m
0.2 0.1 0 0.011 0 2011/2012 2012/2013 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective but need to be vigilant for new sites.
Non Native Plants on South Georgia Season Report 2017/18 Page 10 Elytrigia repens couch grass No couch grass was recorded from Husvik, Leith and Grytviken this season.
6 5 5
4
3 2 2 Coverage sq m
1 0.6 0 0.1 0.1 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective.
Empetrum rubrum diddle-dee The site of the diddle-dee plant at Hestesletten was revisited and no regrowth found. Season Summary: Control effective.
Festuca rubra red fescue Red fescue was treated with glyphosate at all sites this season (previous control with haloxyfop was found to be ineffective). A new small patch was found behind Grytviken and another at Ocean Harbour on Barff Peninsula. All plants were in flower and setting seed.
300 254 250
200 175
150 100 100 80 Coverage sq m
50 0 7.1 0 6.1 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control method changed to glyphosate and now effective. Need to be vigilant for new sites.
Galium saxatile heath bedstraw No regrowth was found this year at the site found next to the walking track near the Maiviken hut.
Season Summary: Control effective.
Non Native Plants on South Georgia Season Report 2017/18 Page 11 Holcus lanatus Yorkshire fog No sign of the single plant found on Brown Flats terraces opposite King Edward Point.
Season Summary: Control effective.
Juncus filiformis thread rush No regrowth was found at the two thread rush sites in Stromness Bay (Husvik whaling station and Kelp Point) this season. This is the 3rd consecutive season of no sign of the plants. Season Summary: Control effective.
Leptinella scariosa feathery buttonweed Sites in the Hansen Valley were followed up this year. A new site with plants in flower was found in the lower Hansen Valley and another in the Leith Harbour whaling station.
400 358 350
300
250
200
150
Coverage sq m 100 50.11 50 13.975 0 2015/2016 2016/2017 2017/2018
Season Summary: Control effective however detection is very difficult and new sites are not unexpected.
Non Native Plants on South Georgia Season Report 2017/18 Page 12 Lobelia pratiana berry-lobelia Follow-up was undertaken on all sites. In addition, twelve new sites, some with plants in flower, were found in Karrakatta Valley; there was a new patch in Hansen Valley and another at a site in Husdal, the latter being the first record for the species in this weed unit; all were treated.
600 510.4 500
400
300 222.43 200
Coverage sq m 90 90 82.78 100 0 0 0.5 0 0 0
Season Summary: Control effective however detection is very difficult and new sites are not unexpected.
Luzula multiflora var congesta heath wood-rush Control has been effective although new outliers were found at the Grytviken site.
0.6 0.5 0.5
0.4
0.3
0.2 Coverage sq m 0.1 0.1 0.03 0 0 0 0 2011/2012 2012/2013 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective but need to be vigilant for outliers in the disturbed ground at Grytviken.
Non Native Plants on South Georgia Season Report 2017/18 Page 13 Nardus stricta mat grass Nothing was found at any of the sites this season.
1.2 1 1 0.75 0.8
0.6
0.4 Coverage sq m 0.2 0.2 0 0 0.01 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective.
Ranunculus acris meadow buttercup A small outlier (in flower) was found at the Karrakatta Valley site this season.
0.25 0.2 0.2
0.15 0.1 0.1 0.1 Coverage sq m 0.05 0 0 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective
Non Native Plants on South Georgia Season Report 2017/18 Page 14 Ranunculus repens creeping buttercup Some follow-up was required at buttercup sites, with some new small plants appearing at Grytviken and Leith Harbour.
30 25.3 25 19 20 14.1 15 11.35
10 Coverage sq m
5 0.46 0.56 0.21 0.02 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective.
Rumex acetosella sheep’s sorrel Follow-up control on all sites (the majority of which were first controlled in 2015/16) was undertaken with an increased number of seedlings noted and many plants in flower and setting seed. New sites were found at Ocean Harbour, on the track between Grytviken and King Edward Point, and on bluffs behind Grytviken; the latter will be a challenge to access.
25000 21503.75
20000
15000
8505.1 10000 7117.5 Coverage sq m 5000 1103 1995.653 36 900 296.68 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective. However, the seedbank has responded and continued follow-up is required. New methods will be required on the inaccessible bluffs at Grytviken.
Non Native Plants on South Georgia Season Report 2017/18 Page 15 Rumex crispus curled dock No plants were found this season.
2.5 2 2
1.5 1.25
1 Coverage sq m 0.5 0.1 0 0 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective.
Sagina procumbens pearlwort (procumbent) Although previous control is effective, small new sites continue to be found in the Stromness Bay area; at some sites (eg along the river margins of the Husdal river and in Husvik whaling station along the river bank), dispersal appears to have been by water-borne seed. Distribution in Stromness Bay is also larger than hoped, probably by reindeer.
50 44 45 40 32.7 35 30 25 20 15 Coverage sq m 10 4.11 2.43 5 1.3 0.66 0.4 1.63 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective, although detecting this small plant is very difficult, With its presence outside of the whaling stations in Stromness Bay it may prove to be over too large an area for effective control. Control to continue at present.
Non Native Plants on South Georgia Season Report 2017/18 Page 16 Scorzoneroides autumnalis Autumn hawkbit Three mature plants (in flower and setting seed) were found this season at the single known site in Karrakatta Valley, indicating that the seedbank is not yet depleted.
6 5 5
4
3
2 Coverage sq m
1 0.2 0.01 0.02 0.04 0.2 0 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective
Stellaria media common chickweed Was among bittercress sites at King Edward Point but not seen for many years. Season Summary: Likely eradicated.
Trifolium repens white clover All known sites were checked. No plants were found this season.
8 7 7 6 6
5
4 3 3 2 Coverage sq m 2
1 0.25 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective
Tripleurospermum indorum scentless mayweed Scentless mayweed, previously recorded at Grytviken, was not seen this season. Season Summary: Likely eradicated.
Non Native Plants on South Georgia Season Report 2017/18 Page 17 Vaccinium vitis-idaea cowberry No plants found this season at the Husdal and Pintail Peninsula sites.
90 85 80 70 60 60 60 50 40 30 Coverage sq m 20 10 0.2 0.1 0.001 0 0 2010/2011 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 Season Summary: Control effective.
Veronica serpyllifolia thyme-leaved speedwell Plants continue to be found (all in flower) and treated at Grytviken.
9 7.7 8 7 6 5 4 3 Coverage sq m 2 1.3 0.6 1 0.06 0.02 0.12 0.08 0.22 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018
Season Summary: Control effective although an active seedbank.
Non Native Plants on South Georgia Season Report 2017/18 Page 18 CLASS TWO SPECIES
Tables for each species show square metres treated this season in each management unit.
Class Two control locations in 2017/18
Agrostis capillaris common bent All known sites were treated on the Thatcher Peninsula, and outlier control was undertaken in other units. Unit sq m treated Bore Valley 3000.2 Brown Flats 950 Godthul 750 Grass Island 0.5 Grytviken 1500 Husvik 30 Olsen 6 Penguin River 20 Prince Olav Harbour 1 Total 6257.7
Season Summary: The Grytviken population continues to be reduced in size however seedbank or root rhizomes persist for longer than hoped. For control on a larger scale elsewhere, methods will need to be improved. Monitoring results this year showed a reduction in cover but not as effective as hoped. Herbicide rates have been increased as a result and next season timings will be assessed to balance the need to control plants early in the season but also having to wait until they are visible.
Non Native Plants on South Georgia Season Report 2017/18 Page 19 Deschampsia cf. parvula punkgrass This grass covers large areas in Karrakatta Valley with a few smaller patches in Husvik whaling station, on Pintail Peninsula and Kelp Point. Following the cessation of grazing by reindeer in 2013, this wind-dispersed species has the potential to spread rapidly within Stromness Bay, colonising mostly sparsely vegetated open ground. Control at the scale required to achieve eradication is not feasible, it may only be possible to contain this species to the Busen region. Season Summary: Monitoring shows that the adult plants can be controlled however the scale of control and follow-up required is not feasible.
Poa pratensis smooth meadow grass Control of this species this season was on small outlier populations and around high visitor use sites at Grytviken and King Edward Point in order to reduce the risk of further spread. This grass continues to show itself as the ecosystem recovers from grazing, and in good growing seasons it may dominate other vegetation. Unit sq m treated Carlita 475.221 Corral 610 Godthul 65 Greene 5 Grytviken 4000 Hound Bay 601 Husdal 25 Husvik 1550 King Edward Point 600 Luisa Bay 300 Prince Olav Harbour 0.65 Reindeer Valley 0.5 Shackleton Valley 450 Sӧrling 150 Total 8832.371
Season Summary: Monitoring results this year showed a reduction in cover but not as effective as hoped. Herbicide rates have been increased as a result and next season timings will be assessed to balance the need to control plants early in the season but also having to wait until they are visible.
Non Native Plants on South Georgia Season Report 2017/18 Page 20 Trisetum spicatum spike trisetum This wind-dispersed grass covers very large areas in Karrakatta Valley, Pintail Peninsula, Shackleton Valley and Hansen Valley with outlier patches at Cape Saunders, Husdal, Olsen Valley, Grytviken, Grass Island and Kelp Point. It was also recorded this season for the first time on Barff Peninsula (at Ocean Harbour). Following the cessation of grazing by reindeer in 2013, this grass has spread rapidly within Stromness Bay where control is not considered feasible. However site-led control at Grytviken, at the Brown Flats site, remains a priority, with two sweeps carried out this season in order to prevent its spread on Thatcher Peninsula. More surveying will be required to determine its distribution at Ocean Harbour.
Unit sq m treated Brown Flats 21.5 Total 21.5
Season Summary: Control is effective at Grytviken although seedlings continue to appear.
Trisetum spicatum on the march, Pintail Peninsula
Non Native Plants on South Georgia Season Report 2017/18 Page 21 CLASS THREE SPECIES
This class consists of Cerastium fontanum (common mouse-ear), Poa annua (annual meadow grass) and Taraxacum officinale (dandelion). These are widespread species especially on the central east coast of South Georgia and large-scale control is not considered feasible. Some control was undertaken at the high-use visitor sites and around buildings at Grytviken and King Edward Cove in order to promote localised recovery of native plant species.
RESEARCH SPECIES
Pernettya pumila Falklands mountainberry
This previously unrecorded species was found this season on the island. It has been tentatively identified as Pernettya pumila, native to the Falkland Islands and South America; samples have been sent to Kew for identification and to add to the herbarium. If confirmed by Kew as a non-native species, it will be listed as a Class One species. A single patch, in full flower, covering approximately 100 sq m was found at 80m above sea level on a steep north-facing rock and scree slope in Hansen Valley. Image below.
Poa spp. More locations have been found and samples taken of a Poa spp. that could possibly be a hybrid between Poa annua and the native tussac Poa flabellata. This has been found in small numbers at widespread sites across the island. We are hoping that the botanists at RBG Kew can shed some light on this plant; however control may not be feasible.
Non Native Plants on South Georgia Season Report 2017/18 Page 22 HERBICIDE USAGE THIS SEASON
Herbicide types and amounts used this season. Herbicide Total used Blue Dye 11,046 ml Flexidor 125 1, 480 ml Glyphosate 360g/L ai 4, 62 6 ml Grazon 90 1,651 ml Haloxyfop 100 10,383 ml Meturon 280 gm Organosilicone 1,981 ml
Herbicide stocktake March 2018. Herbicide On Base Blue Dye 28 litres Flexidor 125 21 litres Glyphosate 360g/L ai 6 litres Glyphosate 510g/L ai 10 litres Grazon 90 29 litres Haloxyfop 100 19 litres Meturon 200 grams Organosilicone 10 litres
Non Native Plants on South Georgia Season Report 2017/18 Page 23 MONITORING
Monitoring plots have been established or measured this season to look at vegetation changes following herbicide applications. This monitoring will improve the Standard Operating Procedures for each species, through a review of herbicide rates, timing of application, and resultant efficacy following each monitoring check and discussions within the field team.
Photo points Photo points were also established at Grytviken and King Edward Point in 2015 to monitor changes in vegetation following control around the buildings and whaling stations. 17 points are being used for annual photographs to show long-term changes in vegetation.
2015 – Bone Cookery 2018 – showing removal of Poa pratenis
2015 – Separator Plant 2018 – showing removal of Poa pratenis also reduction in Taraxacum officinale.
Non Native Plants on South Georgia Season Report 2017/18 Page 24 Herbicide Plots 10m x 10m plots each containing 5 quadrats have been set up and use the same monitoring protocol as the GSGSSI long-term vegetation monitoring programme. These plots have been set up to look at changes following herbicide control. It is too early to see significant results, apart from a reduction in target species. However, herbicide applications have already been adjusted following this season’s visual assessment and discussions amongst the team.
Herbicide plot monitoring sites, locations above and table below
Plot Non Native Species Plot Focus Established Re-surveyed Herbicide efficacy and effect on native PP_1 Poa pratensis community Feb-2017 Feb 2018 Herbicide efficacy and effect on native PP_2 Poa pratensis community Feb-2017 Feb 2018 Herbicide efficacy and effect on native RA_1 Rumex acetosella community Feb-2017 Feb 2018 Herbicide efficacy and effect on native AC_1 Agrostis capillaris community Feb-2017 Feb 2018 Deschampsia cf. Herbicide efficacy and effect on native DP_1 parvula community Feb-2017 Feb 2018 Deschampsia cf. Herbicide efficacy and effect on native DP_2 parvula community Feb-2017 Feb 2018 Herbicide efficacy and effect on native TS_3 Trisetum spicatum community Feb-2017 Feb 2018 Herbicide efficacy and effect on native TS_4 Trisetum spicatum community Feb-2017 Feb 2018
Non Native Plants on South Georgia Season Report 2017/18 Page 25 AC 1 – Agrostis capillaris This Grytviken site showed a reduction in Agrostis cover. It is hoped with a change in timing and herbicide rates the follow-up will be reduced.
2017 2018
DP 1 – Deschampsia cf. parvula This Karrakatta site showed good results for control. However, this is a widespread species, and large-scale control is not feasible. Long term this plot will provide information on the seedbank response.
DP 2 – Deschampsia cf. parvula This Karrakatta site showed good results for control. However, this is a widespread species, and large-scale control is not feasible. Long term this plot will provide information on the seedbank response.
2017 2018
Non Native Plants on South Georgia Season Report 2017/18 Page 26 PP 1 – Poa pratensis This Grytviken site showed a reduction in Poa cover however it is hoped with a change in timing and herbicide rates the follow-up will be reduced.
PP 2 – Poa pratensis This Grytviken site showed a reduction in Poa cover however it is hoped with a change in timing and herbicide rates the follow-up will be reduced.
2017 2018
RA 1 – Rumex acetosella This Grytviken site showed the seedbank response with a few Rumex seedlings appearing, however, all original plants have not regrown.
2017 2018
TS 3 – Trisetum spicatum This Pintail site showed good results for control. However, this is a widespread species that large-scale control over the Busen area is not feasible, although results and seedbank response over time will assist control strategies on other populations.
Non Native Plants on South Georgia Season Report 2017/18 Page 27 TS 4 – Trisetum spicatum This Pintail Peninsula site has shown good results for control and the plot will indicate longer term the seedbank response. However, this is a widespread species that large-scale control over the Busen area is not feasible, although results over time will inform control on other populations.
2017 2018
Non Native Plants on South Georgia Season Report 2017/18 Page 28 Class One Quadrats Further quadrat monitoring of selected Class One species has been set up this season to monitor vegetation recovery following control of non-natives which were growing as a monoculture. A general description of the site along with 1m x 1m quadrat data will be recorded each season. Photos of these sites are also taken to show changes over time.
Class One monitoring sites, locations above and table below.
Plot Non Native Species Plot Focus Established Recovery of native species after herbicide AS-01 Agrostis capillaris control Feb-2018 Recovery of native species after herbicide BB-01 Agrostis vinealis control Feb-2018 Recovery of native species after herbicide DD-01 Empetrum rubrum control Feb-2018 Recovery of native species after herbicide RF-01 Festuca rubra control Feb-2018 Recovery of native species after herbicide SV-01 Anthoxanthum odoratum control Feb-2018 Recovery of native species after herbicide TR-01 Juncus filiformis control Feb-2018 Recovery of native species after herbicide WS-01 Carex aquatilis control Feb-2018 Recovery of native species after herbicide YW-01 Achillea millefolium control Feb-2018
Non Native Plants on South Georgia Season Report 2017/18 Page 29 AS01 – Agrostis stolonifera Quadrat established at Husvik this season.
BB01 – Agrostis vinealis Quadrat established at Grytviken this season.
DD01 – Empetrum rubrum Quadrat established near Grytviken this season.
RF03 – Festuca rubra Quadrat established at Grytviken this season.
SV01 – Anthoxanthum odoratum Quadrat established at Husvik this season.
TR01 – Juncus filiformis Quadrat established at Husvik this season.
WS01 – Carex aquatilis Quadrat established at Husvik this season. An old image was found showing the original population with this year’s photo has been included below.
Carex aquatilis visible as monoculture in 1999 at The native grass Deschampsia antarctica Husvik; image courtesy Basberg (2004). colonising the former area of Carex aquatilis at Husvik in 2018.
YW01 – Achillea millefolium Quadrat established at Grytviken this season.
Non Native Plants on South Georgia Season Report 2017/18 Page 30
The native Alopecurus magellanicus recovering in the Olsen Valley
Non Native Plants on South Georgia Season Report 2017/18 Page 31 SEASON SUMMARY
The ‘South Georgia Non-Native Plant Management Strategy 2016–2020’ has key performance targets(KPI). Results are shown in the table below.
Strategy Targets 2017/18 Season Result
All Class One species will be at zero All Class One species sites controlled population density.
At least 75% of Class One species will be In progress eradicated by 2020.
Class Two populations will be surveyed and Continuing mapped.
10,000 square metres (1 Hectare) of land containing Class Two species will be 15,112 square metres controlled 2017/18 controlled annually.
Class Two non-native plant populations will Areas controlled above included small outlier be reduced in abundance and distribution populations to reduce distribution. annually.
In high visitor traffic areas at King Edward Point and Grytviken, Class Two non-native Follow-up control undertaken this season. plants will be maintained at zero density.
36 additional units surveyed this season as More detailed information will be gathered part of rodent monitoring. Ongoing as on the distribution of Class Three species to opportunities arise to visit remote inform control decisions at outlying sites. management units.
Issues relating to the origin and source of non-native species will be resolved within 12 One new species to classify from this season. months of them being added to the Research Class.
Non Native Plants on South Georgia Season Report 2017/18 Page 32 The chart below shows the number of Class One species sites per season that are active (have mature or juvenile plants present at the visit) or not active in that season. The total number of sites has increased each year as new sites are found and receive control.
250
200
93 150 80 70 Not Ac ve 50 100 Ac ve
124 50 92 95 99
0 2014/2015 2015/2016 2016/2017 2017/2018
Figure 1: Active Class One species sites per season
Non Native Plants on South Georgia Season Report 2017/18 Page 33 RECOMMENDATIONS FOR NEXT SEASON
• Field work is continued as per the ‘South Georgia Non-Native Plant Management Strategy 2016–2020’. • A logistical support request is made as part of pre-season planning to use FPV Pharos SG to access Prince Olav whaling station (for Class One and Two control), Koppen Point in Royal Bay (for survey and Class Two control), Gold Harbour (for survey) and Grass Island (for Class One and Two control) and to support the team based at the Husvik Villa in Stromness Bay. • Cardamine glacialis control should be started prior to Christmas next season to ensure seeds aren’t being becoming viable. • Additional time on the island may be required if climate conditions continue to be favourable to early plant growth. Late growth can be required for detection, however, control needs to be done as early as possible. • Innovative methods will need to be found to control the Rumex acetosella on the bluffs at Grytviken. Methods to reach these plants need to be found, and it may be possible that a drone will be required. • Opportunities to collaborate with citizen science such as the ‘bio blitzing’ project initiated by the vessels National Geographic Explorer and NG Orion should be taken and others investigated. • The new monitoring project in collaboration with RGB Kew and the University of Durham is due to commence next season. This will mean that the Team is on the ground for an extra 2 weeks. This will need to be planned carefully to ensure weed control timings are a priority.
Non Native Plants on South Georgia Season Report 2017/18 Page 34 SOUTH GEORGIA NON-NATIVE PLANT SPECIES 2018
Latin Name Common Name Family Weed Class Weed Category
Achillea millefolium yarrow Asteraceae Class One - Species Led Restricted naturalised
Achillea ptarmica sneezewort Asteraceae Class One - Species Led Restricted naturalised
Aegilops sp goat grass Poaceae Historic Historic
Agrostis capillaris common bent Poaceae Class Two - Site Led Widespread naturalised
Agrostis stolonifera Creeping bent Poaceae Class One - Species Led Persistent
Agrostis vinealis brown bent Poaceae Class One - Species Led Restricted naturalised
Alchemilla monticola velvet lady’s-mantle Rosaceae Historic Historic
Allium schoenoprasum chives Amaryllidaceae Class One - Species Led Persistent
Alopecurus geniculatus marsh foxtail Poaceae Historic Historic
Anthoxanthum odoratum sweet vernal grass Poaceae Class One - Species Led Restricted naturalised
Anthriscus sylvestris cow parsley Apiaceae Class One - Species Led Persistent
Artemisia sp. mugwort Asteraceae Historic Historic
Avena fatua wild-oat Poaceae Historic Historic
Brassica cf. napus rape Brassicaceae Historic Historic
Capsella bursa-pastoris shepherd's purse Brassicaceae Class One - Species Led Persistent
Cardamine glacialis bittercress Brassicaceae Class One - Species Led Widespread naturalised
Carex aquatilis water sedge Cyperaceae Class One - Species Led Persistent
Carex nigra common sedge Cyperaceae Class One - Species Led Restricted naturalised
Carex sp. sedge unknown (not flowering) Cyperaceae Class One - Species Led Restricted naturalised
Carex vallis-pulchrae marsh sedge Cyperaceae Class One - Species Led Restricted naturalised
Carum carvi caraway Apiaceae Historic Historic
Centella sp. centella Apiaceae Historic Historic
Cerastium arvense field mouse-ear Caryophyllaceae Historic Historic
Cerastium fontanum common mouse-ear Caryophyllaceae Class Three - Site Led Widespread naturalised
Dactylis glomerata cocksfoot Poaceae Class One - Species Led Transient
Daucus carota carrot Apiaceae Historic Historic
Deschampsia cespitosa tufted hair-grass Poaceae Class One - Species Led Widespread naturalised
Deschampsia flexuosa wavy hair-grass Poaceae Class One - Species Led Persistent
Deschampsia parvula punk grass Poaceae Class Two - Site Led Restricted naturalised
Elytrigia repens couch grass Poaceae Class One - Species Led Restricted naturalised
Empetrum rubrum diddle dee Ericaceae Class One - Species Led Persistent
Festuca ovina sheep's fescue Poaceae Historic Historic
Festuca rubra red fescue Poaceae Class One - Species Led Restricted naturalised
Galium saxatile heath bedstraw Rubiaceae Class One - Species Led Persistent
Holcus lanatus Yorkshire fog Poaceae Class One - Species Led Persistent
Hypericum tetrapterum square-stemmed St John's-wort Clusiaceae Historic Historic
Juncus filiformis thread rush Juncaceae Class One - Species Led Restricted naturalised
Lactuca sp. wild lettuce Asteraceae Historic Historic
Lamium purpureum red dead-nettle Lamiaceae Historic Historic
Leptinella scariosa feathery buttonweed Asteraceae Class One - Species Led Transient
Lobelia pratiana berry lobelia Campanulaceae Class One - Species Led Restricted naturalised
Lolium multiflorum Italian ryegrass Poaceae Historic Historic
Non Native Plants on South Georgia Season Report 2017/18 Page 35 Latin Name Common Name Family Weed Class Weed Category
Lolium temulentum darnel ryegrass Poaceae Historic Historic
Lotus corniculatus bird's foot trefoil Fabaceae Historic Historic
Lupinus sp lupin Fabaceae Historic Historic
Luzula multiflora var congesta heath wood-rush Juncaceae Class One - Species Led Transient
Matricaria discoidea pineapple weed Asteraceae Historic Historic
Nardus stricta mat grass Poaceae Class One - Species Led Persistent
Pernettya pumila Falklands mountainberry Ericaceae Research To Confirm
Phleum pratense timothy grass Poaceae Historic Historic
Pisum sativum pea Fabaceae Historic Historic
Plantago sp hoary plantain Plantaginaceae Historic Historic
Poa annua annual meadow grass Poaceae Class Three - Site Led Widespread naturalised
Poa pratensis smooth meadow grass Poaceae Class Two - Site Led Widespread naturalised
Poa trivialis rough meadow grass Poaceae Historic Restricted naturalised
Poa unknown(hybrid?) Mutant Poa Poaceae Research
Ranunculus acris meadow buttercup Ranunculaceae Class One - Species Led Transient
Ranunculus repens creeping buttercup Ranunculaceae Class One - Species Led Restricted naturalised
Raphanus sp. radish Brassicaceae Historic Historic
Rorippa islandica Northern yellow-cress Brassicaceae Historic Historic
Rumex acetosella sheep’s sorrel Polygonaceae Class One - Species Led Widespread naturalised
Rumex alpinus alpine dock Polygonaceae Historic Historic
Rumex crispus curled dock Polygonaceae Class One - Species Led Persistent
Sagina procumbens pearlwort (procumbent) Caryophyllaceae Class One - Species Led Widespread naturalised
Scorzonerioides autumnalis Autumn hawkbit Asteraceae Class One - Species Led Restricted naturalised
Senecio vulgaris common groundsel Asteraceae Historic Historic
Sinapis arvensis charlock Brassicaceae Historic Historic
Solanum tuberosum potato Solanaceae Historic Historic
Sonchus sp sow thistle Asteraceae Historic Historic
Stellaria graminea grass leaf starwort Caryophyllaceae Historic Historic
Stellaria media common chickweed Caryophyllaceae Class One - Species Led Transient
Taraxacum officinale dandelion Asteraceae Class Three - Site Led Widespread naturalised
Thlaspi arvense field pennycress Brassicaceae Historic Historic
Trifolium hybridum alsike clover Fabaceae Historic Historic
Trifolium repens white clover Fabaceae Class One - Species Led Persistent
Tripleurospermum indorum scentless mayweed Asteraceae Class One - Species Led Transient
Trisetum spicatum spike trisetum Poaceae Class Two - Site Led Widespread naturalised
Urtica dioica common nettle Urticaceae Historic Historic
Urtica urens annual nettle Urticaceae Historic Historic
Vaccinium vitis-idaea cowberry Ericaceae Class One - Species Led Restricted naturalised
Veronica serpyllifolia thyme leaved speedwell Scrophulariaceae Class One - Species Led Persistent
Non Native Plants on South Georgia Season Report 2017/18 Page 36