The Flora of Fair Isle
Camila Vaitea Quinteros Peñafiel
2016
Thesis submitted in partial fulfilment for the MSc in the Biodiversity and Taxonomy of Plants i
Abstract
Fair Isle, a small island located between Orkney and Shetland just off the northern tip of the British Isles has not enjoyed the same intensity of study of its biodiversity, in particular of the native flora, as other equally remote areas of the British Isles.
This project involved surveying the entire flora of Fair Isle that comprises 19 monads (1km2), which were assessed through a qualitative floristic survey by recording the presence of plant species. This information enabled a comprehensive checklist of 238 species, classified into 27 orders, 59 families and 116 genera according to APG IV. Of the total number of species, 211 are native to the British Isles where 7 are considered under threat and 8 nationally scarce, the rest 27 are introduced species.
A description was done for 9 different habitats that dominate the island. These were verified by the application of TWINSPAN and MAVIS which generated 16 NVC communities.
It is hoped that the results found in this project emphasize the importance of Fair Isle regarding its flora, especially considering that it is home to 55% of the native species found on Shetland and that it has a wide range of plant communities, which are either missing or under serious threat in the British Isles.
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Acknowledgements The following people deserve special thanks for the support and company throughout the development of this thesis:
My amazing supervisors Alex Twyford & Sally Eaton, of whom I feel very lucky to have and proud of the work that we have done together.
The people on Fair Isle, specially Nick Riddiford for his valuable help during the survey and along the project; Lee, Chris and Shaun for making me feel that I never left Fair Isle; to the Fair Isle Bird Observatory Staff and the community; the climbers Rob Woodall & Alan Whatley for their help with the photographic material collected on top of Sheep Rock which contributed to complete the records of all the monads of the island.
Jenny Farrar & Jo Whatmough for their guidance in the fieldwork, taxonomic identification training and the inputs for this project.
My MSc classmates, for their support shown at the moment of the application of this project. For being a group so united, and that took care of each other along the course.
My partner and best friend Kenneth, for his unconditional love, company and encourage to fight for these new challenges.
Morag & Jamie Mellor who gave me the mental and spiritual support during the project and the course. To Jamie Howard & Tessa MacGregor for always keeping me positive and happy.
My family Waldo, Pachy, Tomás & Nicolás who in the distance always made me feel close to home. With their constant admiration, support and love helped me to enjoy at maximum this experience.
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Contents
Abstract ...... i
Acknowledgements ...... ii
Contents ...... iii
List of figures ...... v
List of tables ...... vii
1. Introduction ...... 1
1.1. Description of the study area ...... 2
1.2. Historical Flora of Fair Isle and plant diversity ...... 3
1.3. Aims...... 5
2. Methods ...... 7
2.1. Development of the survey ...... 7
2.2. Fieldwork ...... 7
2.3. Species data collection ...... 8
2.4. Sites surveyed ...... 9
2.5. Habitats data collection ...... 17
2.6. Statistical analysis and interpretation of data ...... 20
3. Results ...... 21
3.1. Fieldwork ...... 21
3.2. Species data collection ...... 22
3.3. Sites description ...... 23
3.4. Collection of data on habitats ...... 30
Inland cliff ...... 31
Sea cliffs ...... 31
Grassland ...... 32
Flush stream ...... 32 iv
Wetland ...... 32
Heathland ...... 32
Disturbed ground ...... 32
Coastland ...... 32
3.5. Statistical analysis and interpretation of data ...... 35
Plant communities from TWINSPAN...... 35
4. Discussion ...... 39
4.1. Implications of a comprehensive checklist for Fair Isle ...... 39
4.2. Native status ...... 40
4.3. Conservation status ...... 41
4.4. Rarity & Scarcity status ...... 42
4.5. Habitat diversity on Fair Isle and its relationship with species diversity ...... 43
4.6. Diversity on Fair Isle compared with other regions of the British Isles ...... 44
4.7. Conservation recommendations for Fair isle ...... 45
4.8. Fieldwork challenges ...... 46
5. Conclusion ...... 47
6. References ...... 48
7. Appendix ...... 52
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List of figures Figure 1 Map showing the location of Fair Isle (red circle) in relation to the United Kingdom (A) and to Shetland (B)...... 2 Figure 2 Map of Fair Isle showing the 19 monads with each grid reference (HZ National Grid), adapted from the Ordnance Survey map “466 Shetland 1:25 000 scale” (A) and the sampling design of the 1km2 unit- monad HZ 2272 (B)...... 8 Figure 3 (A) South Lighthouse, (B) Meoness where the flatness and grassy area is appreciated ...... 9 Figure 4 (A) Malcom’s Head, (B) View of the village from Malcom’s Head ...... 10 Figure 5 (A) The Rippack, (B) Top of Sheep Rock with the climber Rob Woodall (photograph taken by the other climber, Alan Whatley) ...... 11 Figure 6 (A) View of Hoini (110 m) in the back. Pund (ruin) in the left side and Setter (croft) at the right side; (B) Burn of Gilsetter, Jenny Farrar surveying in “The Gully”...... 13 Figure 7 (A) Side of Sheep Rock that belongs to HZ 2271, (B) Lower tail of the hill Ler Ness from Ward Hill...... 14 Figure 8 View of the Airstrip in Homis Dale...... 14 Figure 9 Fair Isle Bird Observatory at the left side, North and South Haven with the beach, and Buness at the right side...... 15 Figure 10 (A) Ward Hill Cairn, view to the west (photograph by Lee Gregory), (B) Burn of Wirvie in the middle, Easter Lother Water in the left, east side at the back...... 16 Figure 11 Cliffs in Geo of Wirvie with sheep grazing ...... 16 Figure 12 View of the North Lighthouse with the fog horn in the very exposed north side... 17 Figure 13 Examples of the habitats: (A) Coastland in HZ 1969, (B) grassland in HZ 2070, (C) sea cliffs in HZ 1970, (D) flush stream in HZ 2172, (E) wetland in HZ 2173, (F) inland cliff in HZ 1970, (G) heathland in HZ 2171, (H) disturbed ground in HZ 2071...... 19 Figure 14 Map showing the total number of species in every monad surveyed...... 24 Figure 15 Map of species found under threat by the “Vascular Plant Red List” (Cheffings et al., 2005) ...... 24 Figure 16 Threatened species present on Fair Isle as classified by the “Vascular Plant Red List” (Cheffings et al., 2005): (A) Coeloglossum viride (VU), (B) Mertensia maritima (NT), (C) Gentianella campestris (VU), (D) Hymenophyllum wilsonii. (E) Radiola linoides (NT). 29 vi
Figure 17 Map of the location of habitats surveyed. (SC) Sea cliffs; (IC) Inland cliffs; (H) Heathland; (G) Grassland, (W) Wetland; (FS) Flush stream; (DG) Disturbed ground and (C) Coastal...... 30 Figure 18 Wetlands found on the island: (A) Easter Lother Water; (B) Burn of Gilly; (C) Burn of Wirvie; (D) Golden Water; (E) “The Gully” and (F) Potamogeton polygonifolius one of the main species found in Wetland and Flush stream habitats...... 34 Figure 19 TWINSPAN tree of 134 samples classified into one group at level one, one group at level three, one group at level four and ten groups at level five. Plant species codes are presented in Appendix 5...... 35
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List of tables Table 1 Collection of monads surveyed in this study...... 21 Table 2 Summary of the flora of Fair Isle organised by division, order, family, genus and species. All taxa followed the APG IV (Byng et al., 2016) ...... 22 Table 3 Breakdown of most well represented plant families on Fair Isle...... 23 Table 4 Ranking of the ten most widespread species on the island...... 23 Table 5 Habitats surveyed during the study, number of monads where they were found and the percentage of the island covered by each...... 31 Table 6 National Vegetation Classification (NVC) and Countryside Vegetation System Classification (CVS) communities most frequently proposed by MAVIS for groups created from TWINSPAN ...... 36 Table 7 Ellenberg values most frequently proposed by MAVIS for groups created from TWINSPAN ...... 37 Table 8 Result of the interpretation of communities generated by MAVIS from groups created by TWINSPAN by allocating them on habitats surveyed during the fieldwork...... 38 Table 9 Number of vascular plants found in Great Britain, Shetland and Fair Isle with this study...... 41
1
1. Introduction Oceanic islands provide many spectacular examples of adaptation, unlikely colonisation events, and species radiation. The study of island ecology, conservation and biogeography, has provided inspiration not just to Charles Darwin and Alfred Russel Wallace, the two co- discoverers of evolution by natural selection, but to naturalists, biologists and zoologists from all over the world as well. Such is the case of the appearance of Theory of Island Biogeography by MacArthur & Wilson (1967) where they state that “small islands, supporting small communities, are more prone to lose species than large ones”. An important reason why islands are so biologically interesting is that their variation in size, shape, degree of isolation and ecology, make them excellent natural laboratories that allow researchers to study ideas, state hypothesis, test and make predictions using models and develop theories about dispersal, colonisation and adaptation (MacArthur & Wilson, 1967; Berry, 2009)
So why it is important to study the diversity of islands? Remote islands are often under- surveyed, and together with the isolated nature, islands can give a unique opportunity for the study of the origin, dispersal and establishment of species. The small size of islands makes it possible to compile full floristic inventories, as well as a comprehensive understanding of the relationship between area and species diversity. Many islands in Scotland already have complete inventories of their flora, like the island of Foula (Barkham et al., 1981), the islands in the Outer Hebrides (Pankhurst & Mullin, 1991), the islands of Tiree, Gunna & Coll (Pearman & Preston, 2000), the island of Skye and adjacent islands (Murray & Birks, 2005), the island of Iona (Millar, 2006), the island of Rum (Pearman et al., 2008). By having an understanding of the biodiversity and ecology of an island, it is possible to compare like for like between islands.
Berry (2009) suggested the enormous benefits of islands for biological research because of their relatively uncomplicated ecology and often extreme environments. In addition to this, Wood & Bunce (2016) make reference to the surprising fact that, considering the expansion of ecological research on the northern territory of British Isles, there has been very little interest in the overall vegetation of Shetland for the last 30 years.
Fair Isle is a small, remote island found halfway between Orkney and Shetland, and is part of the northern temperate zone. Its oceanic climate is greatly influenced by its small size and location close to one of the major tracks followed by North Atlantic depressions. The island is 2 one of the windiest lowland sites in the British Isles, and despite this it may support an important diversity of species relative to its size.
1.1. Description of the study area The Vice-County1 112, Shetland, is the northernmost and most isolated part of the British Isles. The sub- Arctic Archipelago of Shetland is a group of more than one hundred islands, islets and skerries, forming the northernmost Scottish administrative unit, whose capital is Lerwick. Most of the islands are clustered around the largest island, the Mainland, with Fair Isle and Foula, more distant.
A B
Figure 1 Map showing the location of Fair Isle (red circle) in relation to the United Kingdom (A) and to Shetland (B).
Fair Isle is a small island about 5 km (3 miles) long by 2,5 km (1,5 miles) wide with an area of 768 hectares. It is situated approximately 42 km (27 miles) NE of North Ronaldsay in the archipelago of the Orkney Islands and 39 km (24 miles) SW of Sumburgh Head on the southern tip of the Mainland of Shetland (see Figure 1A, B). It lies at a latitude of
1 Geographical division of the British Isles used for the purposes of biological recording and other scientific data-gathering. 3
59.552142°N and a longitude of 1.628637°E. Bathed by the North Atlantic sea, its position reveals the influence of a northerly oceanic climate to its vegetation.
Famous for being the most remote inhabited island in the United Kingdom, its traditional knitwear is world renowned. It also has traditional crofting, important seabird colonies which are important breeding grounds for thousands of puffins amongst many other seabirds, is a stopover point for rare migratory birds, and captivates people with its magic and breath-taking scenery. Fair Isle has been owned by the National Trust for Scotland (NTS) since 1954.
The geology of Fair Isle is relatively simple and constitutes of sedimentary sandstone from between the Lower and Middle Old Red Sandstones. The Old Red Sandstones, were sand and mud laid down initially a lake environment and then windblown sands during the Devonian geological period between 410 and 360 million years ago (Hunter, 1996).
Proctor (2013) argue that plants are never perfectly evenly distributed on the round, neither at random, and that some degree of clumping is almost always present. On Fair Isle it is known by casual observations that there is some pattern of distribution. Therefore, it might be possible to determine which plants tend to group together in distinctive ways, and how they interact in relation to their habitat.
1.2. Historical Flora of Fair Isle and plant diversity Fair Isle had several botanical surveys undertaken over the last 120 years, but they were not done consistently over that time period. The first and main document of the flora of Fair Isle was done by James Trail2 in 1906. He was unaware that any earlier collection of the plants of Fair Isle had been made or examined, except a few notes by Mr. William Hadden Beeby on his botanical explorations Shetland. In 1905, Mr. Eagle Clarke, left to James Trail in Aberdeen, Scotland, samples preserved with formalin of plants observed during his stay on the island. These samples were mostly in good condition for determination. In addition to Clarke’s samples, Mr. Beeby and Mr. Benneth sent to Trail lists of the species seen by them in 1894. Within those lists, a letter was included as well with comments about the flora of the island:
“The scantiness as compared with that of Shetland. Distinct traces of an Atlantic and Germanic flora on west and east sides, although at widest one-mile west to east, more shown,
2 Professor of Botany in the University of Aberdeen 4 perhaps, in forms than in distinct species. Low altitude of Salix herbacea (217 meters) on the Ward Hill, and alpine aspect of other species at this elevation, e.g. Luzula sylvatica3.”
From that collection, Trail (1906) prepared a full statement of the 136 species found on the island, in view of its isolation.
Pritchard (1956), conscious that no records of the plants appeared since that of Trail (1906), he decided to contribute in a second paper on the Fair Isle flora. In that list of vascular plants, he named 183 plants. His list included 48 species not recorded by Trail, while 26 species recorded by Trail were not seen by him. Those data were analysed by Fitter (1959) with a list done by himself, supplemented by a list supplied to him by Mrs. Hannah Stout (a native islander) with a list that covers the period 1930-1948. According to Fitter (1959):
“It seems probable from these lists that even on a small island, not only may local resident plants easily be overlooked, but colonists may frequently appear and die out.”
Currie (1960) with material collected on Fair Isle and based on his private herbarium, made a detailed note on plant distribution within the island. He arranged the data in 12 new records, five confirmatory records suggested by Fitter (1959) in his final list of 25 plants recorded on the authority of Mrs. Stout alone, and four plants recorded by Trail (1906), but not by Pritchard (1957) or himself (1959).
Palmer & Scott (1963), in their visit to Fair Isle made a detailed study of the flora. They recorded most of the species recorded by Trail (1906), Pritchard (1957), Fitter (1959) and Currie (1960). They even included unpublished records done by other observers and arranged a paper with 24 new records, and confirmations of 11 species reported from Fair Isle by Mrs. Hannah Stout but thought by Fitter (1959) to be in need of verification.
“A Check-List of The Flora of Fair Isle” by Scott (1971) was published with some 238 taxa, with the suggestion that future botanical research try to confirm the existence of the plants he named as “doubtful” and set a list of 15 species widespread over the rest of Shetland, but absent from Fair Isle. This is the last exhaustive study done specifically for the flora of Fair Isle.
With the publication of “The flowering plants and ferns of the Shetland Islands” by Scott & Palmer (1987), it came up the number of species found on Shetland with the mention of some
3 Letter from the Rev. Straker to Mr. Benneth 5 important species on Fair Isle. Although this is later than Scott’s (1971) publication, it is not a detailed study for Fair Isle’s vegetation.
It is of main interest to know the native status of the plant species in a study, if a comparison with other islands is desired. Under this context, the use of the New Atlas of the British and Irish Flora (Preston et al., 2002) is essential. The New Atlas makes the important distinction between native species, i.e. those occurring in Britain and Ireland as a result of natural dispersal, and introduced, non-native species known or thought to have been brought by man either accidentally or on purpose. In the case of non-native species, it is possible to distinguish between those species known or suspected to have been introduced before AD 1500 (archaeophytes) and more recent introductions (neophytes). This distinction is an important platform for future studies using these data, such as Hill et al. (2004), which assessed the status of the vascular plants throughout Great Britain by including all native and archaeophyte species in a Red Data List and using IUCN4 criteria.
For other native species, and some non-native species which can be included if they are long- established and of cultural significance (i.e. archaeophytes), there are others categories not based on IUCN Criteria such as Nationally Rare (occurring in 15 or fewer hectads5) and Nationally Scarce (occurring in 16-100 hectads) (Lockton et al., 2005).
1.3. Aims Not much information is known about the flora and more specifically the habitats of Fair Isle apart from a series of checklists with species name and location done through time by Scott (1971), Palmer & Scott (1965), Currie (1960), Fitter (1959), Pritchard (1957) and Trail (1906). Specifically, none of these texts give details of the distribution of species across the island, nor related this to diversity of habitats. These historic data sets, led to the basis for this current research project. The major aims are, firstly to assess the flora of Fair Isle through a qualitative floristic survey by recording the presence of the species. This will allow generation of a comprehensive checklist of the flora of Fair Isle, updated with classification of APG IV (Byng et al., 2016). An exhaustive analysis of the flora will also be undertaken to show how many species are native, introduced, under threat, nationally rare and scarce.
Secondly, this research project will endeavour to identify species that tend to form distinguishable assemblages in distinctive habitats. This data will be verified with the
4 International Union for Conservation of Nature and Natural Resources. 5 An area of 10 km x 10 km square. 6 application of the ecological software TWINSPAN and MAVIS, in which it will be possible to determine if NVC communities are present on Fair Isle.
It is hoped that these new insights will make us know whether Fair Isle has an important and high number of plant species or not. 7
2. Methods 2.1. Development of the survey To meet the aims previously described, the project involved a comprehensive floristic survey of the island in monads, detecting presence of all Angiosperms, Gymnosperms, Lycopodiophyta and Pteridophyta. Bryophytes, lichens, fungi and algae were not included in the survey. The reason why effort was focused on Angiosperms is because it is one of the most diverse and ecologically important groups of plants, and has the most data available to allow comparisons with other areas. The survey methodology of recording in one km grid square was the same as that used for plant recording by the BSBI so that these records could contribute to the BSBI6 Atlas 2020.
Research was done in the Royal Botanic Garden Edinburgh Library, to get to know an approximate number of species and type of flora that potentially is present on the island. Relevant sources were BSBI Database (2015), Clarke (1906), Currie (1960), Fitter, (1959), Pritchard (1957), Scott (1971) and Trail (1906).
2.2. Fieldwork The fieldwork started with training by Jim McIntosh, Scottish Officer of the Botanical Society of Britain & Ireland (BSBI) at the Royal Botanic Garden Edinburgh in early June 2016. The training consisted of survey technique using BSBI recording cards, tips to improve wildflower identification skills and monad recognition using GPS.
On Fair Isle, the monad recognition was done in the Ordnance Survey map “466 Shetland 1:25000 scale”, as shown in Figure 2A, where 19 monads were chosen for the recording. The sample survey sites (or monads) were based on 1 km2 units selected from the whole island (see Figure 2B). Map of individual monads are provided in Appendix 2.
Initial field recording was carried out on Fair Isle from 6th – 27th June 2016, with assistance from Jenny Farrar and Jo Whatmough. Other records were made with Nick Riddiford. Further records after my field survey were added.
6 The first atlas of the British and Irish flora was published in 1962. A repeat atlas was published in 2002 based on fieldwork carried out from 1987-1999. BSBI is now producing a third atlas, Atlas 2020, which will be published after fieldwork has been completed in 2019.
8
A B
Figure 2 Map of Fair Isle showing the 19 monads with each grid reference (HZ National Grid), adapted from the Ordnance Survey map “466 Shetland 1:25 000 scale” (A) and the sampling design of the 1km2 unit- monad HZ 2272 (B).
2.3. Species data collection Each monad was visited and presence or absence of each species recorded on BSBI recording cards (see Appendix 3). When it was not possible to identify a species in the field, specimens were collected (plus close-up photographs, detailed notes about the possible record and GPS grid reference) and taken back for identification. Most identifications followed Collins (2009), Poland (2009) and Rose (1989) for grasses, rushes and sedges (Poaceae, Juncaceae and Cyperaceae respectively). If that method did not allow the species to be identified, plants were pressed and shown to experts to get confirmation.
A check-list of the species found is presented in Appendix 1 according to APG IV (Byng et al., 2016), synonymy was checked in The Plant List (2013) and Tropicos (2016), and the authority was checked in IPNI (2012).
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2.4. Sites surveyed The island was divided into 19 monads. Each of these monads presents a distinct assembly of habitats, and interesting histories, as describe below.
HZ 1969
Located at the southwest of the island at the end of the track, this is one and a half hour walk from the Bird Observatory. The highest altitude here is 20 m. This monad comprises Shalstane, a mass of shallow stone offshore. The rocky ridge of Shalstane shelters an extensive tidal rock pool system from a coast exposed to the full force of Atlantic breakers (Riddiford, 2004). After Shalstane, the South Lighthouse (see Figure 3A) stands on a little hard mound (Outer Skadden) just in from the Kletts7. It was rebuilt after World War II bombing. In 1998 it became the last lighthouse in Scotland to be automated. Along the east coast is Muckle Uri Geo8, an area of bedrock with a beach which is sheltered from the sea by the ridge of kletts, except during exceptionally severe weather. A monad without cliffs, and with one of the strongest “tide rips” around Fair Isle. The most southerly point of the island is Head of Tind9. One of the two series of skerries and reefs, and approximately 400 m from Head of Tind, is the most southerly extremity of Fair Isle “Da Skerry”, a rock with no vegetation.
A B
Figure 3 (A) South Lighthouse, (B) Meoness where the flatness and grassy area is appreciated
7 Klett: a low rock (Eunson et al., 2007) 8 Geo: steep- sided narrow inlet (Riddiford, 2004) 9 Tind: “taing”- a narrow strip of land; or “teinds”- the tenth part (Eunson et al., 2007) 10
HZ 2069
In this monad is the South Harbour at Kirkie10 Geo, a shelving shingle beach guarded by several offshore stacks. Following the east coast direction is Udi Geo, a man-made upper beach once used for drying fish, Mid Geo, where is The Puffin Hostel (a work camp hostel). The cemetery is found in this monad. Meoness (see Figure 3B), is relatively flat, with grassland area and cliffs of nearly 36 meters. The second skerry, and approximately 200 m from Head of Tind, is “Da Keels”, a rock with no vegetation. Two crofts are found here: Utra (the southernmost house) and Springfield (a self-catering let).
HZ 2169
This is a very small monad in the south east coast with an altitude of approximately 30 m.
HZ 1970
This monad is located along the western coastline of the island. In here there are two headlands, North and South Reva. From 1914, North Reva became a narrow inlet and South Reva in two natural arches where the sea comes through and breaks on a little beach. This monad is distinguished by the pasture of the large and steep headland as it is shown in Figure 4A, Malcom’s Head at 107 m. Dangerous, high and rugged cliffs grazed by sheep are found among the coast of this monad, as well as a series of Holms11, arches and stacks.
A B
Figure 4 (A) Malcom’s Head, (B) View of the village from Malcom’s Head
10 Kirkie: name from the old Kirk, now just a wall (Eunson et al., 2007) 11 Holm: a small island (Eunson et al., 2007) 11
HZ 2070
Monad characterized by the village as shown in Figure 4B. Twenty crofts are found here: Aesterhoull, Brecks, Busta, Burkle, Houll, Auld Haa, Kennaby, Koolin, Lower Leogh (currently not occupied), Lower Stoneybrek, Midway (currently not occupied), North Shirva (the Nurse's house), Nether Taft, Quoy, Schoolton, Shirva, Skerryholm, Stackhoull (also known as Rock Cottage, only shop and post office of the island), Taft and Upper Leogh. Also the Fair Isle Primary School; the Hall; The George Waterston Memorial Centre and Museum; The Methodist Chapel and Church of Scotland Kirk; the wind electricity generator; the Coastguard Rescue Hut and the Fire Station.
HZ 2170
With the presence of a big square geo (Swartz Geo), this monad presents a maximum altitude of 52 m. The Rippack (Figure 5A), is a trip of land with presences of large and small caves has a mixture of grassland and rocks.
A B
Figure 5 (A) The Rippack, (B) Top of Sheep Rock with the climber Rob Woodall (photograph taken by the other climber, Alan Whatley)
HZ 2270
This monad includes a rock of 132 m called “Sheep Craig” or “Sheep Rock” that was connected to the island by a land bridge, but has long since fallen away. Nowadays is still joined by a lower, heavily eroded and impassable ridge, the only access is by sea followed by rock climbing. Sheep Rock in its totality belongs to four monads, the part that correspond to HZ 2270 is the southeast corner- particularly perpendicular. This is painted white with seabird guano during the busy breeding season (Riddiford, 2004). The outside of the rock is called “The Ruff” or “O’ Da Ruff”, a very clean-cut face above the water but quite jagged below (Eunson et al., 2007). This monad was not going to be included in the survey due to the very 12 difficult access. While the fieldwork was being done, on the 25th June, the climbers/ hill baggers Alan Whatley and Rob Woodall arrived to the island (one of them keen botanist) with the intention to climb the hump12 “Sheep Rock” as is shown in Figure 5B, by traditional shepherd’s route from sea with roped climb and alternated lead. With photographs and notes, after the climbing and Nick Riddiford’s expertise the identification of species was done.
HZ 1971
This small monad in the western coast comprises Krista or “Keesta13”, name given to the grassy cliffs and its land of approximately 80 m long x 25 m wide. It is located in Hoini (HZ 2071), the other high piece of land of the island.
HZ 2071
This monad comprises another high piece of land, Hoini14 as is Figure 6A at 110 m. The Muckle Geo of Hoini and the South Geo of Hoini, which has a rough beach that is inaccessible from the land. This is an extremely exposed and windy point. The Burn of Gilly, coming down to the sea at Hyukni Geo is found in this monad.
Five crofts are found here: Barkland, Chalet (health centre), Field (home to the island's meteorological station), Setter (the most northerly occupied croft) and Upper Stoneybrek. Pund is currently a ruin (formerly a croft). It was originally planned it to house the island's first bird observatory, before the buildings at North Haven became available (FIBO, 2016).
An important section of the island is the Hill Dyke (or “Feely15 Dyke”), possibly dating from the Neolithic period. This originally ran between the east and west coasts, separating the north and south of the island dividing territories or farming land. A much later stone dyke runs parallel to it, showing the continuity of land use between prehistoric people and recent residents. The purpose is nearly the same, to separate the inhabited area of crofts and inbye land (to the south) and the common grazing of uninhabited moorland (to the north) (National Trust for Scotland, Fair Isle Five Thousand Years [Pamphlet]).
12 Humps are hills of any height with a drop of 100 metres or more on all sides. The name Hump stands for HUndred Metre Prominence (Edwardes, 2001) 13 Keesta: another rounded point of land (Eunson et al., 2007) 14 From the ON “honni” meaning crag (Hunter, 1996) 15 Feely: Shetland word for turf (National Trust for Scotland, Fair Isle Five Thousand Years [Pamphlet]). 13
A B
Figure 6 (A) View of Hoini (110 m) in the back. Pund (ruin) in the left side and Setter (croft) at the right side; (B) Burn of Gilsetter, Jenny Farrar surveying in “The Gully”.
HZ 2171
Following the coast, Vaasetter is found with an altitude of 110 m. The land bridge that connects Sheep Rock to Vaasetter is found in this monad, as well as a tiny piece of the grassland on top of it. No crofts are present here. Interesting points of attraction are: the sheep wash, bird traps monitored by the Bird Observatory, a quarry, a burn called “Burn of Gilsetter” (see Figure 6B) heading through “The Gully” down to the sea at a smooth run of cliff called Funniquey (or Finniequoy).
HZ 2271
This monad includes three different places of the island. One of them is the continuation of Vaasetter, where a rock- fishing seat called Hillia Tind (or Heela Tind- Taing) is found.
The second one is the rough grassland where the vegetation on Sheep Rock is and shown in Figure 7A. The name Sheep Rock it is attributed to in times past, a flock of some 16 Shetland ewes and a tup (ram) was kept on those 4,5 hectares of pasture on its sloping top. The islanders managed the sheep twice a year to clip (shear) wool and remove lambs. Rowing out from South Harbour, scrambling onto slippery rocks, climbing an almost perpendicular cliff using a chain suspended from the top, and animals lowered by rope to the boats below. This was done until 1977 (Riddiford, 2004). The last area of the monad is the south end of the peninsula Buness called South Gavel. 14
A B
Figure 7 (A) Side of Sheep Rock that belongs to HZ 2271, (B) Lower tail of the hill Ler Ness from Ward Hill.
HZ 2072
Monad located in the west coast, it comprises the lower tail of the hill Ler Ness16 as shown in Figure 7B, a sloping wet piece of ground. Burrista is next, a type of peninsula in between the two geos North and South Naaversgill (or Noversgill). The highest point of this monad is about 150 m in Burrashield17. Sukka Moor and the south end of the Airstrip are found here.
HZ 2172
The highest point in this monad is about 150 m. The rest of the Airstrip as is shown in Figure 8 is located in here with two burns: Burn of Vatstrass (a little stream that runs down from Homisdale to the sea) and Burn of Furse. Two quarries are also found here.
Figure 8 View of the Airstrip in Homis Dale.
16 Lerness from ON “leir” meaning clay (Hunter, 1996) 17 Name indicative of land use, “shieling” (Hunter, 1996) 15
HZ 2272
This monad is quite spectacular in terms of being the first encounter that you have with the island if you arrive by boat. The highest point in this monad is nearly 50 m.
Along the coast cliffs around 20 m high are found. Just opposite the Bird Observatory (see Figure 9) in “Landberg” there are indications of an early habitation, some sort of fortification maybe dating from the Iron Age (Riddiford, 2004), with a series of old earthen walls across the narrow headland (ideal place for a fortress), the cliffs are steep but not high. In South Haven, there is a stone dyke built to protect the road that runs across the peninsula. At the east side of the monad is Buness, a fine peninsula that from the cliff-top, stones are covered in summer in a mass of yellow lichen (the south part of Buness, South Gavel belongs to the monad HZ 2271). North Gavel is the north side of Buness. In North Haven a beach of fine and white sand is found, and its Stack of North Haven (joined in 1996 to Buness by a breakwater to provide a sheltered harbour). The breakwater consists of over 20.000 tons of granite rock imported from Norway. North Haven has been the principal harbour for Fair Isle, where the Ferry Terminal is found, as well as the slipway for the Ferry “Good Shepherd IV” (Eunson et al., 2007).
At the west side of the monad, and with a history that dates back to 1948, the Fair Isle Bird Observatory is found. The current Observatory building was completed in July 2010.
Figure 9 Fair Isle Bird Observatory at the left side, North and South Haven with the beach, and Buness at the right side.
HZ 2073
Monad in the west coast of the island, where the highest point is found, Ward Hill (217 m) as is shown in Figure 10A. This area includes remains of a World War II radar station and 16 accommodation huts, as well as large stone and turf enclosures for housing anti-aircraft battery and machine guns (National Trust for Scotland, Fair Isle Five Thousand Years [Pamphlet]). North Fellsigeo is where the cliffs are the highest on the island. Most of the geos are inaccessible from the top. It also comprises the upper part of the hill Ler Ness (which its lower part belongs to monad HZ 2072).
A B
Figure 10 (A) Ward Hill Cairn, view to the west (photograph by Lee Gregory), (B) Burn of Wirvie in the middle, Easter Lother Water in the left, east side at the back.
HZ 2173
In here the northernmost cliffs are found, ridges of rocks sloping to the sea. Burn of Wirvie as is shown in Figure 10B, which runs down from Wirvie Brecks and Easter Lother Water.
HZ 2273
This monad is almost cliffs from the east side as shown in Figure 11, with a very interesting and diverse landscape. Points of interest such as the Burn of Wirvie which runs down to the sea from Wirvie Brecks (monad HZ 2173). Following to the north, just next to the track that leads to the North Lighthouse (monad HZ 2274) is the Golden Water, close to the edge of a cliff, in a high square prehistoric burial cairn piece of moorland called “Mopul”.
Figure 11 Cliffs in Geo of Wirvie with sheep grazing 17
HZ 2074
This is a very small monad where “Dronger”18, marks the western extension of the north coast of Fair Isle.
HZ 2274
This monad is the most exposed northeast corner of the island, where the track ends and the North Lighthouse rise (see Figure 12). The landslip is very evident from the sea and, between the lighthouse and the foghorn, there is a crack where the middle part of the cliff has fallen out of alignment with the cliffs on either side at some time in the past. The Kiln of Skroo is a sheltered spot against the gales. This lighthouse, a tower of nearly 14 m was opened in 1892.
Figure 12 View of the North Lighthouse with the fog horn in the very exposed north side.
2.5. Habitats data collection A classification of habitats by visual categorization was made for the island. This was done in those monads surveyed by myself and the help of Jenny Farrar and Jo Whatmough. In those monads surveyed by Nick Riddiford and the climbers, the habitat description was done with photographs. This description allowed statistical comparison between monads and a later evaluation with NVC communities. The different types of habitats mentioned next, represent the most likely presence of physical characteristics of the island of presumed importance to plants in each monad.
Coastland
This habitat relates to the land adjacent to the sea, that forms a shingle beach. Is used for places without cliffs and are at sea level (see Figure 13A)
18 From ON “drongr” meaning pointed rock (National Trust for Scotland, Fair Isle Five Thousand Years [Pamphlet]) 18
Grassland
Areas with herbaceous vegetation, some degree of agriculture and sheep/cattle grazing. This includes unimproved, semi improved and improved grasslands (see Figure 13B)
Sea cliffs
Due to the long coastline, the cliffs are too exposed to have much vegetation. In this habitat, areas with cliffs formed by rock are found. It is one of the main habitats as it surrounds the island in its totality (see Figure 13C)
Flush stream
Patches of damp, associated with water movement like a small watercourse. Most of the times this flushes were not shown on the map (see Figure 13D)
Wetland
This habitat includes wet areas such as open waters, with submerged, free floating or floating leaved vegetation (see Figure 13E)
Inland cliff
Grassland or heathland in rock surface that include maritime species, present on shallow slopes or on cliff tops (see Figure 13F)
Heathland
Areas with presence of Calluna vulgaris or other Ericaceae presents on the island (see Figure 13G).
Disturbed ground
Areas with presence of quarries or excavations (see Figure 13H) 19
A B
C D
E F
G H
Figure 13 Examples of the habitats: (A) Coastland in HZ 1969, (B) grassland in HZ 2070, (C) sea cliffs in HZ 1970, (D) flush stream in HZ 2172, (E) wetland in HZ 2173, (F) inland cliff in HZ 1970, (G) heathland in HZ 2171, (H) disturbed ground in HZ 2071.
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2.6. Statistical analysis and interpretation of data A database of species presence/absence was made, in a file modified from the BSBI format to enter records from a BRC recording card (using the BRC codes). Data such as: BRC Code, taxon name, common name, site name, grid reference number, recorder, date and stage in some species were included. Floristic tables were produced for each monad and habitat (see Appendix 4).
To compare my visual assessment of habitats, with a more statistical clustering of vegetation types, I used TWINSPAN for Windows 2.3 (Hill & Šmilauer, 2005). This also allows me to compare my habitat types with the major classification of vegetation, i.e. NVC plant communities. Data from 134 widespread species were used for analysis. The data were coded as presence or absence for each monad. The setting used were: one for cut level, no weights for samples, species nor pseudospecies levels, five for maximum number of division levels, three for minimum group size per division and zero for the maximum number of indicator species per division. These settings are standard for the software, and were chosen because the recording of the species was done in terms of presence/absence.
The analysis was carried out, by entering the TWINSPAN classifications into MAVIS (2015) for Ellenberg scores for light, fertility, wetness and substrate pH; Countryside Vegetation System (CVS) and National Vegetation Classification (NVC).
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3. Results 3.1. Fieldwork The survey was done by me with the help of Jenny Farrar & Jo Whatmough, the local ecologist Nick Riddiford and the two climbers Rob Woodall & Alan Whatley (see Table 1) that helped to survey the flora on top of Sheep Rock on HZ 2270.
Table 1 Collection of monads surveyed in this study.
N° Monad Recorder(s) Survey date 1 HZ 2272 Camila Quinteros, Jenny Farrar & Jo Whatmough 08/06/2016 2 HZ 2271 Camila Quinteros, Jenny Farrar & Jo Whatmough 09/06/2016 3 HZ 2171 Camila Quinteros, Jenny Farrar & Jo Whatmough 10/06/2016 Camila Quinteros, Jenny Farrar & Jo Whatmough 11/06/2016 4 HZ 2071 Camila Quinteros 19,21/06/2016 5 HZ 1969 Camila Quinteros, Jenny Farrar & Jo Whatmough 11/06/2016 Camila Quinteros, Jenny Farrar & Jo Whatmough 11/06/2016 6 HZ 2069 Nick Riddiford 12/07/2016 7 HZ 2172 Camila Quinteros 12/06/2016 8 HZ 2274 Camila Quinteros 13/06/2016 9 HZ 2273 Camila Quinteros 13/06/2016 10 HZ 2173 Camila Quinteros 14/06/2016 11 HZ 2073 Camila Quinteros & Nick Riddiford 15/06/2016 12 HZ 2072 Camila Quinteros & Nick Riddiford 16/06/2016 13 HZ 2070 Camila Quinteros & Nick Riddiford 17/06/2016 14 HZ 1970 Camila Quinteros 18/06/2016 15 HZ 2170 Camila Quinteros & Nick Riddiford 20/06/2016 16 HZ 2169 Camila Quinteros & Nick Riddiford 20/06/2016 17 HZ 2270 Climbers Alan Whatley & Rob Woodall 25/06/2016 18 HZ 2074 Nick Riddiford n. d 19 HZ 1971 Nick Riddiford n. d
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3.2. Species data collection From June 2016 to July 2016, 238 species of vascular plants in vegetative, flowering or fruiting stage were recorded as shown in the complete checklist (Appendix 1). These records belong to five divisions, 27 orders, 59 families, 116 genera, 228 species plus 10 species (Narcissus sp., Taraxacum sp. Atriplex sp. Lonicera sp., Callitriche sp. Euphrasia sp. Salix sp., Abies sp. Sorbus sp., Ribes sp.) not identified to species level and recorded as “sp.”, and noted in brackets in Table 2. Angiosperms was best represented in terms of number of orders, which could be divided into Eudicots and Monocots.
Table 2 Summary of the flora of Fair Isle organised by division, order, family, genus and species. All taxa followed the APG IV (Byng et al., 2016)
Division Order Family Genus Species
Pteridophyta 4 9 10 12 Lycophyta 2 2 2 2 Gymnosperms 1 2 3 2 (+1) Angiosperms/ Monocot 4 10 4 71 (+1) Angiosperms/ Eudicot 16 36 97 141 (+8) Total 27 59 116 238
The total number of species was divided into native status according to (Preston et al., 2002) as follows: 211 natives, 13 archaeophytes (those that became naturalised in the UK prior to AD 1500) which are: Aegopodium podagraria, Narcissus sp., Capsella bursa-pastoris, Polygonum arenastrum, Ballota nigra, Lamium confertum, Lamium purpureum, Mentha x piperita, Anchusa arvensis, Myosotis arvensis, Euphorbia helioscopia, Abies sp. and Ribes sp.; 13 neophytes (became naturalised since AD 1500) which are: Crocosmia x crocosmiiflora, Hyacinthoides x massartiana, Aster x salignus, Matricaria discoidea, Senecio smithii, Fallopia japonica, Symphytum x uplandicum, Epilobium ciliatum, Picea sitchensis, Alchemilla mollis, Rosa rugosa, Rubus spectabilis and Acer pseudoplatanus; and one casual (which are non-native and not naturalised) which is Avena strigosa.
The family of Angiosperms with the largest number of species was Poaceae, followed by Asteraceae, Cyperaceae, Caryophyllaceae, Polygonaceae as it is shown in Table 3. These five families comprise 39% of all observed species.
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Table 3 Breakdown of most well represented plant families on Fair Isle.
Ranking Family N° of genus N° of species % of all family 1 Poaceae 21 29 12 2 Asteraceae 16 21 9 3 Cyperaceae 6 20 8 4 Caryophyllaceae 6 13 5 5 Polygonaceae 4 12 5 Total 53 95 39
3.3. Sites description A number of species were found to be highly abundant across the island. The ten most abundant species included shrubs, herbs, grasses, sedges and rushes, were found in almost all survey squares (see Table 4). Most notably, Armeria maritima was found in every monad, and across an extremely diverse range of habitats (discussed below). As well as being widespread, many of these species were extremely abundant in a given monad and appear to play a disproportionately important role in these ecosystems.
Table 4 Ranking of the ten most widespread species on the island.
Ranking Species Monads (%) 1 Armeria maritima (Plumbaginaceae) 100 2 Festuca rubra (Poaceae) 95 3 Plantago coronopus (Plantaginaceae) 95 4 Plantago maritima (Plantaginaceae) 95 5 Calluna vulgaris (Ericaceae) 89 6 Cochlearia danica (Brassicaceae) 89 7 Luzula campestris (Juncaceae) 89 8 Plantago lanceolata (Plantaginaceae) 89 9 Scilla verna (Asparagaceae) 89 10 Silene uniflora (Caryophyllaceae) 89
As a reference on the map in Figure 14, it can be traced even the total number of species per monad. An analysis of the species present in each sampled monad is discussed below, as well as the type of habitat found. Also it is pointed out on the map in Figure 15, the detection of species under threat in some monads of the island and its photographs in Figure 16. 24
Figure 14 Map showing the total number of species in every monad surveyed.
Figure 15 Map of species found under threat by the “Vascular Plant Red List” (Cheffings et al., 2005) 25
HZ 1969
Presence of 74 different species are found in this monad. Habitats such as coastland, grassland and sea cliffs. Species only found here are: Cakile maritima and Euphrasia ostenfeldii. Plants under threat are: Mertensia maritima, Near Threatened (NT); Spergula arvensis, Vulnerable (VU); Viola canina Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2069
Presence of 106 different species. Habitats such as grassland and flush stream. Inside the cemetery it is found Fallopia japonica a non-native invasive scrub species. Presence of Radiola linoides and Viola canina, both Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2169
Presence of 30 different species. This small monad presents inland cliffs habitat without much diversity.
HZ 1970
Presence of 62 different species. Habitats such as coastland, grassland and sea cliffs. No unique species for this monad.
HZ 2070
Presence of 153 different species. Habitats such as wetland and inland cliff. This monad includes crofting areas and cultivated land with a grassland of different character which are, or have been cut for hay. Muddy disturbed ground in the neighbourhood of crofts supports an open community of low growing plants, as it is also mentioned by Palmer & Scott (1987). This is the most diverse monad with unique presences on the island such as: Aegopodium podagraria, Anchusa arvensis, Arrhenatherum elatius, Atriplex patula, Avena strigosa, Carex hostiana, Comarum palustre, Euphorbia helioscopia, Galeopsis bifida, Galeopsis tetrahit, Persicaria bistorta, Persicaria maculosa, Sonchus arvensis. Presence of species under threat such as: Gentianella campestris, Vulnerable (VU); Radiola linoides, Near Threatened (NT); and Spergula arvensis, Vulnerable (VU) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005). 26
HZ 2170
Presence of 73 different species. Habitats such as inland cliff, flush stream and sea cliffs. No unique species for this monad.
HZ 2270
Presence of just eight different species: Atriplex glabriuscula, Puccinellia distans subsp. borealis, Tripleurospermum maritimum, Cochlearia officinalis, Rumex acetosa, Silene uniflora, Festuca rubra and Armeria maritima.
HZ 1971
Presence of 30 different species. Only inland cliff was described for this monad. No unique species for this monad.
HZ 2071
Presence of 152 different species. Habitat such as wetland, inland cliff and disturbed ground. Species only found in this monad are: Cardamine flexuosa, Centaurea nigra, Epilobium ciliatum, Filipendula ulmaria, Hyacinthoides x massartiana, Leucanthemum vulgare. Presence of species under threat such as: Gentianella campestris, Vulnerable (VU); Radiola linoides, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2171
Presence of 142 different species. Habitats such as heathland, sea cliffs, wetland, flush stream and grassland. Planted tree species are found in this monad such as Picea sitchensis, and Acer pseudoplatanus also found in HZ 2272. Other species found only in this monad are: Ballota nigra, Blechnum spicant, Carex dioica, Dryopteris filix-mas, Polypodium vulgare, Ribes sp. Rubus spectabilis, Sorbus aria and Ulex galli. Presence of species under threat such as: Hymenophyllum wilsonii, Near Threatened (NT); Radiola linoides, Near Threatened (NT); Spergula arvensis, Vulnerable (VU); and Viola canina, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
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HZ 2271
Presence of 33 different species. Habitats such as grassland and sea cliffs. The top of Sheep Rock in this monad, its habitat was not surveyed. Presence of species Viola canina, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2072
Presence of 102 different species. Only sea cliffs were surveyed in this monad. Presence of Coeloglossum viride, Vulnerable (VU); and Radiola linoides, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2172
Presence of 107 different species. Habitats such as grassland, heathland, wetland, flush stream, disturbed ground and inland cliffs. Presence of Radiola linoides, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2272
Presence of 119 different species. Habitats such as grassland, heathland, wetland, sea cliffs and coastland. One Abies species is found here (it could be Abies procera but requires to be checked), Alchemilla mollis, Lonicera sp., Sorbus sp. and the other Acer pseudoplatanus. Presence of species under threat such as: Coeloglossum viride, Vulnerable (VU); Radiola linoides, Near Threatened (NT); and Viola canina, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2073
Presence of 80 different species. Habitats such as heathland, flush stream, disturbed ground, inland cliffs, sea cliffs and top of Ward Hill (217 meters). Presence of species under threat such as: Coeloglossum viride, Vulnerable (VU); Hymenophyllum wilsonii, Near Threatened (NT); and Radiola linoides, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
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HZ 2173
Presence of 107 different species. Habitat such as grassland, heathland, wetland, flush stream and inland cliffs. Species only found here are: Botrychium lunaria, Huperzia selago and Trientalis europaea. Presence of species Hymenophyllum wilsonii, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2273
Presence of 87 different species. Habitats such as heathland, wetland, flush stream, inland cliffs and sea cliffs. Neottia cordata is only found in this monad. Presence of species Hymenophyllum wilsonii, Near Threatened (NT); and Radiola linoides, Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
HZ 2074
Presence of five different species: Montia fontana, Cochlearia danica, Plantago coronopus, Plantago maritima and Armeria maritima. The habitat was described as inland cliff, because it does not have characters proper of heathland or grassland.
HZ 2274
Presence of 37 different species. Habitats such as grassland, disturbed ground and inland cliff. Presence of species under threat such as: Coeloglossum viride, Vulnerable (VU) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005).
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A B
C D
E
Figure 16 Threatened species present on Fair Isle as classified by the “Vascular Plant Red List” (Cheffings et al., 2005): (A) Coeloglossum viride (VU), (B) Mertensia maritima (NT), (C) Gentianella campestris (VU), (D) Hymenophyllum wilsonii. (E) Radiola linoides (NT). 30
3.4. Collection of data on habitats After the arrangement of habitats through visual categorization on the island, a recording of presence of species on each habitat was done. In Figure 17, it can be seen the occurrence of eight different habitats. As it is an island, the cliffs are the main landscape and every monad has presence of them, but it was not possible during this survey to describe them all because of the extreme exposure of some. Overall habitats are well spread on the island. Heathland is more concentrated on the north side of the island, where the communal sheep grazing is found.
Figure 17 Map of the location of habitats surveyed. (SC) Sea cliffs; (IC) Inland cliffs; (H) Heathland; (G) Grassland, (W) Wetland; (FS) Flush stream; (DG) Disturbed ground and (C) Coastal.
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A basic habitat structure described for the island is shown in Table 5, a breakdown of individual descriptions is discussed below the Table.
Table 5 Habitats surveyed during the study, number of monads where they were found and the percentage of the island covered by each.
Habitat Species N° Monads % of the island Inland cliffs 49 11 58% Sea cliffs 44 10 53% Grassland 81 8 42% Flush stream 60 7 37% Wetland 84 7 37% Heathland 63 6 32% Disturbed ground 26 4 21% Coastal 12 3 16%
Inland cliff Cliff tops where the circumstances are not clear enough to distinguish between grassland and heathland. In this situation, those sites were called “inland cliffs”, where the conditions are harsh, and this exposed land is made up of mostly of salt tolerant plants. This habitat was found in 11 monads, representing the 58% of the total surveyed. From those 11 monads that present this habitat, 3 were recorded only with this habitat: HZ 2169, HZ 1971 and HZ 2074. The more frequent species in this kind of habitat were: Plantago lanceolata, Scilla verna, Jasione montana, Euphrasia sp., Potentilla erecta, Luzula campestris, Calluna vulgaris, Plantago coronopus, Sagina procumbens, Trifolium repens, Cerastium fontanum, Armeria maritima. Festuca rubra.
Sea cliffs All the monads have presence of sea cliffs but just ten were recorded, representing the 53% of the total habitats. Some of the cliffs needed to be surveyed by boat, which it could not be possible for this study. Main plants species found are: Silene uniflora, Armeria maritima, Lotus corniculatus, Festuca rubra, Plantago maritima, Plantago lanceolata, Scilla verna, Rumex crispus, Silene dioica, Plantago coronopus, Jasione montana, Ligusticum scoticum and Sedum rosea. 32
Grassland Also named as “pastures”, the coastal pasture it is thought to be the purest form of grassland in Shetland, which is characteristic of the cliff tops where it is kept low by grazing sheep (Palmer & Scott, 1987). Nine monads out of 19 were found with this habitat, representing the 42% of the total surveyed. This habitat has presence of: Sagina procumbens, Festuca rubra, Plantago maritima, Potentilla anserine, Stellaria media, Cirsium vulgare, Plantago lanceolata, Scilla verna and Trifolium repens.
Flush stream Seven monads were found with flush stream habitat, representing the 37% of the habitats surveyed. Main species present in this habitat are: Hydrocotyle vulgaris, Sagina procumbens, Carex nigra, Festuca rubra, Juncus articulatus, Potamogeton polygonifolius and Ranunculus flammula.
Wetland Seven monads were found with wetland areas, representing the 37% of the total surveyed. Main wetland habitats are: Burn of Wirvie and Easter Lother Water in HZ 2173 (Figure 18A), Burn of Gilly and Vaadal in HZ 2071 (Figure 18B), Golden Water and the continuation of Burn of Wirvie in HZ 2273 (Figure 18 C, D), Burn of Furse and Burn of Vatstrass in HZ 2172, Burn of Gilsetter and “The Gully” in HZ 2171 (Figure 18E) and Sukka Moor in HZ 2072. Main species found on wetland are: Ranunculus flammula, Potamogeton polygonifolius, Cardamine pratensis, Callitriche stagnalis, Hydrocotyle vulgaris, Juncus articulatus, Glyceria fluitans, Carex nigra, Taraxacum sp., and Plantago lanceolata.
Heathland Six monads were found with heathland habitat, representing the 32% of the total surveyed. Main species present in heathland are: Calluna vulgaris, Scilla verna, Potentilla erecta, Plantago maritima, Anthoxanthum odoratum, Luzula campestris, Trifolium repens, Cerastium fontanum, Festuca rubra, Holcus lanatus, Carex pilulifera, Thymus polytrichus, Nardus stricta, Galium saxatile.
Disturbed ground Four monads were found with disturbed ground, representing the 21% of the total surveyed. Main species found here are: Cirsium vulgare, Plantago maritima, Holcus lanatus, Plantago coronopus, Viola palustris, Bellis perennis, Plantago lanceolata and Stellaria alsine.
Coastland Also named as “Shingle and boulder beaches” (Palmer & Scott, 1987). Three monads were found with this habitat: HZ 1969- South Lighthouse, HZ 1970- Malcom’s Head and HZ 2272- 33
North Haven, representing the 16% of the habitats surveyed. Three species were common: Atriplex spp., Festuca rubra and Galium aparine, which fits with the description of Palmer & Scott (1987) that this habitat sometimes does not have vegetation beyond species of the Atriplex group and Galium aparine that are confined to this in habitat in Shetland. Mertensia maritima is important to highlight, because it is found as Near Threatened (NT) category in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005). Other species found are: Cirsium arvense, Glaux maritima, Plantago coronopus, Plantago maritima, Potentilla anserina, Puccinellia distans, Rumex crispus and Stellaria media.
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A B
C D
E F
Figure 18 Wetlands found on the island: (A) Easter Lother Water; (B) Burn of Gilly; (C) Burn of Wirvie; (D) Golden Water; (E) “The Gully” and (F) Potamogeton polygonifolius one of the main species found in Wetland and Flush stream habitats.
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3.5. Statistical analysis and interpretation of data Plant communities from TWINSPAN The structure of the TWINSPAN divisions is shown as a tree in Figure 19, and the output from the TWINSPAN classification after being tested on MAVIS is summarised in Table 6. According to the 5th level results of TWINSPAN classification, the 134 samples were classified into 13 clusters. The first dichotomy of the data set at level one was divided into two different sized groups; 131 samples and three samples (Huperzia selago, Trientalis europaea and Carex bigelowii), species that were found in the same monad HZ2173 creating a community (#13). The first group was divided at level two into a subgroup of 85 and 46 samples. At level three, four subgroups were formed with 44, 41, 45 samples and the community of Salix herbacea (#12). At level four six subgroups were formed, the first gave origin to another community (#1), the followings with 17, 15, 26, 16 and 29 samples. At level five, ten communities were formed three (#2), 11 (#3), eight (#4), seven (#5), four (#6), 22 (#7), 12 (#38), four (#9), nine (#10), 20 (#11) samples.
Figure 19 TWINSPAN tree of 134 samples classified into one group at level one, one group at level three, one group at level four and ten groups at level five. Plant species codes are presented in Appendix 5. 36
Table 6 shows the NVC and CVS communities which most closely resemble the TWINSPAN communities. The higher the match value is; the more confident MAVIS is of the community assigned. However, the results should only be used as a guide. A match value of around 50% is acceptable, but due to the amount of species overlap there is between similar NVC communities it would be unusual to have much higher value. The community with the highest score of 48% is group # 2 which comprised three species of the 53 included in the NVC classification for this community of Mountain streamside. The community with the lowest match score of 15% was group # 6 which comprised four species of the 37 included in the NVC classification for this community of streamside.
Table 6 National Vegetation Classification (NVC) and Countryside Vegetation System Classification (CVS) communities most frequently proposed by MAVIS for groups created from TWINSPAN
Countryside Vegetation System Classification National Vegetation Classification (NVC) TWINSPAN (CVS) group Match Code Name Code Name value #1 M15a Mires 19% 74 Moorland grass on wet peat Mountain stream sides and slightly #2 H10d Heathland 48% 79 enriched moorland grass #3 H9d Heathland 30% 67 Moorland grass #4 H7d Heathland 17% 67 Moorland grass #5 CG10a Calcareous grassland 17% 65 Acidic herb rich grass/heath Streamside/flushes in wet moorland #6 OV20 Open vegetation 15% 74 grass Streamside/flushes in wet moorland #7 SD17d Sand dune 18% 74 grass #8 MC10a Maritime cliff 27% 40 Ryegrass/Yorkshire fog grassland #9 OV28 Open vegetation 24% 30 Mixed eutrophic grassland #10 MC12b Maritime cliff 21% 30 Mixed eutrophic grassland #11 SD3 Sand dune 27% 28 Eutrophic tall herb/grassland Acid grassland/ #12 U12c 37% 89 Montane heather moorland upland Acid grassland/ #13 U10b 24% 93 Montane heath vegetation class upland 37
Although the match scores are reasonable considering the methodological approach taken (being a walkover survey as opposed to a standard NVC survey using quadrats), it is not surprising that the communities of plants found on Fair Isle would not be a 100% match to those found in the NVC, due to the its isolated nature from mainland (either Orkney or Shetland), its exposed position in the North Sea, and high latitude nearly 60°N.
From the Ellenberg values in Table 7, the interpretation of the main values is explained according to Hill et al., (2004). Light values show little variation ranging from 7 to 7.5. It would be unlikely to find very much variation within this variable as there is very little shade casting vegetation on the island, being largely highly grazed and open. In the wetness item the higher value of 8.6, “dampness indicator”, the group #7 matches with the inclusion in the flush stream habitat. In the pH, this values reflects preferences for soil acidity, where it is remarkable the low value as an acidity indicator for the groups #2 (pH 4.3) and #4 (pH 4) allocated to heathland habitat. In fertility value, a general indication of preference for soil fertility, lower value corresponds to plants with high stress tolerance, showing that in general the plant communities are between indicators of more or less infertile sites (2.6) to intermediate fertility (5.8).
Table 7 Ellenberg values most frequently proposed by MAVIS for groups created from TWINSPAN
TWINSPAN group Light Wetness pH Fertility #1 7,2 6,9 5 3,6 #2 7 5 4,3 2,7 #3 7 6,2 5 3,7 #4 7,4 6 4 2,6 #5 7,5 6,8 6,3 3,8 #6 7,3 5,9 4,3 2,9 #7 7,5 8,6 5,7 3,6 #8 7,4 5,4 5,2 3,7 #9 7,5 5,8 5,8 4,5 #10 7,2 5,3 6 5 #11 7,2 6,4 6,4 5,8 #12 7,2 6 5 5 #13 7,2 6,4 5,8 5,8 38
TWINSPAN communities are assigned to the habitats which were designated during the survey stage in an attempt to consider the diversity of plant communities present within each of the habitats identified. In Table 8, the number of NVC communities are shown in each of the habitats. The habitat groupings were very general and broad in their resolution, whereas the TWINSPAN analysis picks out communities at a finer grain. The NVC communities in the Flush stream i.e. SD17d (Potentilla anserina-Carex nigra dune-slack community, Hydrocotyle vulgaris-Ranunculus flammula sub-community) suit once the floristic NVC table was checked. Other communities are well suited to their habitats e.g. maritime cliff (MC10a, MC12b, SD3) in sea cliffs is agreeable; coastal grassland (CG10a) in grassland habitat and, the heathland communities (H7d, H9d, H10d) clearly belong to the heathland habitat. The NVC community “acid grassland/upland” (U10b and U12c) was considered to be included in a new habitat (Montane habitat) due to it matches to where the species were found, monads where the higher point of 217 meters is found on the island (HZ2073 and HZ2173).
Table 8 Result of the interpretation of communities generated by MAVIS from groups created by TWINSPAN by allocating them on habitats surveyed during the fieldwork.
Habitats NVC Communities
Coastal -
Grassland CG10a
Sea cliffs MC10a, MC12b, SD3
Flush stream SD17d
Wetland M15a
Inland cliffs -
Heathland H7d, H9d, H10d
Disturbed ground OV20, OV28
Mountain habitat U10b, U12c
39
4. Discussion The aim of this study was to assess the flora of Fair Isle through a floristic survey. The main outputs were a comprehensive checklist of the flora, determination of the community types present on the island, and an evaluation of those species considered under threat. In this chapter, the finding that Fair Isle contains an assemblage of 238 species is discussed, as well as the significance of the nine habitats and 16 NVC communities. Further research is also suggested.
4.1. Implications of a comprehensive checklist for Fair Isle The total number of vascular plants species recorded in this study is 238, and includes 27 orders, 59 families and 116 genera. Three families, Poaceae (29 species), Asteraceae (21 species) and, Cyperaceae (20 species) contributed disproportionately to the total island diversity. The most dominant family on the island, Poaceae, also known as the grass family is one of the most widely distributed and abundant groups of plants on Earth, more specifically, the fifth-largest vascular plant family of all Angiosperms, while the second most dominant family, Asteraceae, is the second-largest family of all Angiosperms (Christenhusz et al., 2016). The geographically isolated location of Fair Isle suggests that wind dispersal could be a major mechanism for colonising the island. In this case, it makes sense that that these families are the most dominant on the island and may be because their seed and fruit dispersal mechanism is by wind, as well as the pollination mechanism by the same element, also called “anemophily”, that is correlated with small and numerous flowers common in the Asteraceae family and the Poales clade (Poaceae, Cyperaceae and Juncaceae) (Simpson, 2006). Without neglecting the traditional farming (crofting) history on the island, where grasses are the main source of food for animal grazing, hence its importance and presence. The breeding system is another likely explanation of the strong presence of this families, such as asexual reproduction (e.g. rhizomes, bulbils, stolons), where its importance can be found in the numerous propagules than can be generated relatively quickly and efficiently, by permitting plants to colonise without another partner to reproduce with.
The total number of 238 species, is the best estimate available given the narrow recording period. Bearing in mind that the field survey was done in June 2016, and that plants on Fair Isle flower late and thus some species were likely to be missed, such as the case of 10 new species as shown on Appendix 6, that were not included in the total number (Nick Riddiford, personal communication, 12th August 2016). Moreover, a handful of plants were not identified to a single species (i.e. recorded as sp.) as fruits would be needed to identify the 40 species. By analysing all historical records by Scott (1971), Palmer & Scott (1965), Currie (1960), Fitter (1959), Pritchard (1957), Trail (1906) and data from the BSBI Database (2015), it is deduced that 28 species might be extinct because of their absence on the island since last 10 years; 11 mistaken species may be an error because their presence is doubtful; 15 species are synonyms but included on previous checklists; 27 doubtful species where is not known if they were extinct, mistaken, introduced or present on the island but with lack of expertise to identify during this survey; and 1 species (i.e. Carex ovalis, first and only island record) found by Riddiford (2002), never seen again. All the previous records are shown on Appendix 6. It follows that the vegetation of Fair Isle is still somewhat incomplete and more thorough research is needed by surveying throughout the complete flowering and fruiting season of the vascular plants. However, this statement does note attempt to present a main problem. The concordance between my survey in this project and previous field surveys suggest that most of the diversity present on the island has now been documented.
The results from this project cannot be used to identify changes in the distribution of species, not even frequency (abundance was not considered in this project), due to the nature of the study design. However, islanders have provided verbal accounts of changes in species abundance which would be worthy of future investigation. Though speculative, it is likely that changes in the island life, such as the arrival of new families to inhabit small rented farms, called crofts, with the condition to keep the traditional farming, that comprises a plot of arable land attached to the house with a right of pasturage held in common with other such farms, could have driven these changes. Although this aspect is difficult to evaluate without detailed records and without a long term established research project. Another likely explanation about the change in the distribution of species, could be the climate change. Where, for example, the decrease of rainfall may affect those wet habitats that give home to species found under threat and/or nationally scarce (e.g. Radiola linoides, Apium inundatum, Hymenophyllum wilsonii) causing their extinction.
4.2. Native status A comparison of the species number is shown in Table 9. In the broader context of Britain and Ireland, the number of vascular plant species in the New Atlas of the British & Irish Flora (Preston et al., 2002) is 2951. The study of the flowering plants and ferns of Shetland (Scott & Palmer, 1987) is known to consist of 827 reliably recorded taxa including native, colonists, hybrids, naturalised, casuals and plants of garden. in Table 9, for Shetland is given the number of species as well as the percentage of plants found on Britain and Ireland. For Fair 41
Isle the species number are given in the percentage found on Shetland and Britain and Ireland (UK).
Of the total number of species found on Fair Isle, 211 species are native (75% of the total number of species) which is equivalent to the 55% of the native plants on Shetland and 15% of the native plants for Great Britain. Considering the land area of Fair Isle, which covers just 7.68km² (or 768 hectares), compared to Shetland which is over 10 times the size at 1,466 km², we can see that this value is very high. This value could be related with the presence of different habitats that allow the establishment of a diversity of species.
Table 9 Number of vascular plants found in Great Britain, Shetland and Fair Isle with this study.
United Kingdom Shetland Fair Isle
(2002) (1987) (2016) % N° % N° % % UK N° % % UK Shetland
Total 2951 100 827 100 28 238 100 29 8
Natives 1407 48 383 46 27 211 75 55 15
Archaeophytes 149 5 15 2 10 13 5 5 9
Neophytes 1155 39 181 22 16 13 5 5 1
Casuals 240 8 86 10 36 1 0.3 0.4 0.4
Plants of garden - - 162 20 - - - - -
4.3. Conservation status Seven species on Fair Isle are included in the Vascular Plant Red Data List for Great Britain (Cheffings et al., 2005). Three in the vulnerable category (Coeloglossum viride, Gentianella campestris and Spergula arvensis), and four under near threatened category (Hymenophyllum wilsonii, Mertensia maritima, Radiola linoides and Viola canina).
Some taxa are still relatively widespread; they are undergoing rapid decline in Great Britain. Some species like Coeloglossum viride, Gentianella campestris and Spergula arvensis (all vulnerable) have been recorded for Fair Isle since Trail (1906), which means that these species have been present on the island for 110 years. Those species in the class “near 42 threatened” were first recorded on the island as follow: Hymenophyllum wilsonii by Hannah Stout in Fitter (1959), Mertensia maritima on the 4th September 1992 by NJ Riddiford & PV Harvey as “two small non flowering plantlets, one central and the other farther up the shingle, Muckle Uri Geo beach” (Nick Riddiford, personal communication, 12th August 2016), Radiola linoides by Currie (1960) and, Viola canina by Pritchard (1956).
Internationally, the British Isles are known to have a large expanse of heather- dominated vegetation of mostly Ericacae (e.g. Calluna vulgaris, Empetrum nigrum and Erica cinerea) associated with Juniperus communis subsp. nana, one of the habitats seen and described on Fair Isle and backed up with the NVC communities. On this island, this community is found in its prostrate, dwarf form of growth. Supporting populations of birds, protection for smaller plants, and non-vascular plants as well associated with heather-dominated communities than with grassland. Research on the main types of biological and climatic damage associated with this particular habitat is suggested. By comparing this particular habitat with other sites of the British Isles, it can be seen whether diversity of these biological associations is high.
Nine different habitats were identified through this project. Though this number is low overall in comparison with Shetland and its 15 described habitats (Scott & Palmer, 1987), considering the nature of data collection being a general walkover survey as opposed to targeted NVC surveys, the small size of the island, the traditional farming that keeps the communal animals on the heathland at the north side of the island that are heavily grazed, it can be said that Fair Isle has a high number of habitats. Therefore, is vital to do further research on habitats diversity, e.g. it would be valuable to repeat the habitat description done in this study by considering the Phase 1 Habitat Survey methodology (JNCC, 1990) to allow a straight forward comparison.
4.4. Rarity & Scarcity status Euphrasia foulaensis, Euphrasia ostenfeldii, Mertensia maritima, Ophioglossum azoricum, Polygonum boreale and Puccinellia distans were found as a Nationally Scarce taxa listed on the BSBI web site (BSBI, 2016). In many cases it is the Nationally Scarce species which are of the greatest interest ecologically, rather than just for their rarity. It is often the case that a such species are indicators of good quality habitat (Lockton et al., 2005).
No Nationally Rare species were found for Fair Isle, according to the latest official list of conservation statuses for all UK plants listed on the BSBI web site (BSBI, 2016). Nationally 43 rare species are those that are found in 15 or fewer hectads19 in Great Britain (Lockton et al., 2005). It could be that as though the plant diversity of this island is high for its size, current practices (e.g. modern agriculture, situation of drainages) could be leading to species decline. It could also be that these species have already gone extinct due to continuous high levels of grazing. Being present on this small and remote island, there is always a chance that these populations become vulnerable to extinction. Adding the isolation component, the site is unlikely to be recolonised. However, the presence of these six species, does not necessarily mean these species are declining. Across the rest of the British Isles, to be named as “scarce species” is because it has been subjected to severe habitat destruction over the last 40 years. It is known that scarce species on Fair Isle have been constantly exposed to some kind of natural menace, e.g. strong winds that cause sea storms covering the coastland, habitat of Mertensia maritima. Therefore, this is a good reason to study the abundance of these species on the island and design a conservation programme before the result of the study be from a scarce species to rare.
4.5. Habitat diversity on Fair Isle and its relationship with species diversity The British Isles are surrounded by sea cliffs, where land and sea come close together with a very distinctive vegetation. Fair Isle and its maritime cliff habitat is a good example. With striking effects on its vegetation by the strong winds, many of these species are small due to the rate of water loss and cooling the growing points than by mechanical damage. Proctor (2013) makes reference to the low-growing and prostate forms of many species, such as the species on Fair Isle, are common on exposed sea-cliffs.
Currie (1960) pointed out his attention to the boreal species on the island. He names those geographical groups as Northern Montane Element (Antennaria dioica, Listera cordata, Trientalis europaea), Oceanic Northern Element (Armeria maritima, Atriplex glabriuscula, Cochlearia danica, C. officinalis, Honkenya peploides, Narthecium ossifragum, Silene maritima, Thymus drucei), Artic- Subarctic Element (Ligusticum scoticum) and Arctic-Alpine Element (Carex bigelowii, Empetrum nigrum, Polygonum viviparum, Salix herbacea, Sedum rosea and Silene acaulis). This is important because on Fair Isle a montane habitat as present on the high peak of 217 meters. Proctor (2013) says “what constitutes a mountain depends on where you are, and who you ask”. To consider the presence of this community reflects notable difference between British mountains and those of central Europe where alpine plants can be distinctively prominent. It is recommended to establish baseline monitoring of this area
19 An area 10 km x 10 km square. 44 as a precursor to assessing the impacts of climate change on Fair Isle's arctic-alpine plants and communities.
Some grasslands and many heaths are two-layered, with a field layer of the dominant flowering plants which in this study it was possible to recognise. The second layer is the ground- layer of mosses, liverworts and lichens which was not included for this study. It will add more value to the surveys of island biodiversity to have a more complete and detailed study of the flora of Fair Isle, including this group. This is important as these species contribute a great deal to Scotland’s biodiversity (Proctor, 2013)
Because the recording arrangement of plant communities was not a true habitat classification, i.e. not following the “Phase 1 Habitat Survey methodology” (JNCC, 1990), it is suggested that further research could be done to meticulously evaluate the structure and dynamics of the vegetation. This is important because with the results shown in this study, including the low match values for the NVC communities, could indicate that communities on Fair Isle, are not well covered in the published NVC communities. It may be that Fair Isle has distinct communities different to the rest of the British Isles. It is known that this NVC classification does not provide the last word on the classification of the vegetation types the of British Isles (NVC manual), and that the vegetation on Fair isle can provide an example of the deficiencies in the coverage and the unexplained variation of these generalise habitat types.
4.6. Diversity on Fair Isle compared with other regions of the British Isles There are a lot of factors that complicate the comparison of flora between islands, such as: geology, history, isolation and distance with the mainland, climate, human impact, as well as localised factor affecting genetic variation and local adaptation. Even so, some general interpretations of the diversity can still be made.
Overall it would seem that the number of species on the checklist is very high, especially considering that more species could be added to the checklist by having an extended field season. This value also seems high considering the small surface area (768 hectares) and the relatively modest variation in elevation (the highest peak is just 217 meters).
By comparing with the island of Foula (another Shetland Island) with a bigger surface than Fair Isle (1,265 hectares) and a highest elevation of 418 meters, it has an estimated number of 254 species (Barkham et al., 1981), of which about 162 are native to Shetland. This compares with the 211 natives found on Fair Isle. This comparison supports the idea that Fair Isle contains relatively high diversity. 45
4.7. Conservation recommendations for Fair isle An up to date flora of Fair Isle, with an associated overview of the plant communities, is a good launching pad for future botanical research. Although limited by the time available to do a more meticulous survey, an interesting amount of data is available now. For example, it is known that Fair Isle has six species that are nationally scarce, three in the vulnerable category and four near threatened according to the Vascular Plant Red List for Great Britain. These species must be evaluated in terms of their habitat requirements before decisions are made of a program of conservation, such as whether it is better to apply a species-based or habitat- based action plan. It is also imperative to establish a monitoring programme, and programme of management, that can act in response to future climate change.
For example, it is an advantage to know that the population of true artic-alpine species found in Montane habitats (e.g. Salix herbacea, Polygonum viviparum, Carex bigelowii, Trientalis europaea), where according to previous botanical studies on the islands have not become extinct. By monitoring the sensitive arctic–alpine species found at unusually low elevations (i.e. 207 meters on Fair Isle) could serve as an early warning of the effects of climate change in a global context.
On the Red List for the British Isles, Cheffings et al. (2005) make reference to groups of plants that are remarkably difficult to include in threat assessments. Much of the difficulty associated with these groups comes from species identification problems. This challenging species identification also makes it difficult to establish whether Fair Isle is a hotspot for these taxonomically complex species groups. Fair Isle is a hotspot for two groups: the Euphrasia group where seven species were identified during this survey, a highly critical genus with over 60 wild hybrids and active speciation (Cheffings et al. 2005). Several of the emergent taxa narrowly distributed and endemic to the British Isles. In addition to Euphrasia, three species of Dactylorhiza were recorded, without recording the individual subspecies. This is a difficult genus owing to hybridisation between almost all of the taxa, and active speciation is evidently taking place (Cheffings et al. 2005).
It would be interesting to look at the presence of bracken (Pteridium aquilinum). This work has been requested by local ecologists, who are interested in researching the factor that limit its growth. This is concerning because this species is found mostly in heathland habitat in five monads in the north side of the island where a range of species can grow in association with Calluna vulgaris. The reason why bracken is ecologically important is because it can form 46 striking circles in the course of invading grassland by spreading its underground rhizomes, being more difficult to control and preventing other plants growing (Proctor, 2013).
Since the 1970s, there appears to be a trend towards higher average temperatures and wetter winters in Shetland (Wood and Bunce, 2016), therefore it is highly recommended to assess any potential effects of climate change. An advantage here is the small size of the island, whereas it is more difficult to study in a less well defined area.
4.8. Fieldwork challenges The main challenge for fieldwork is the expertise of the surveyor. An accurate identification of the species is compulsory. Some species require a high level of knowledge for identification such as species of the Poaceae family like Deschampsia and Agrostis; the genus Juncus, Euphrasia. Some of these species need to be fruiting and/or with seeds to be correctly identified (e.g. some species of the genus Carex and Atriplex). As such, additional species might have been present, but may have been overlooked or not recorded due to their similarity to other taxa. After the survey, some species of Carex, Agrostis, Deschampsia, Euphrasia, Atriplex remained uncertain.
As it is widely known, the weather in Scotland is very often a limitation for fieldwork. Fair Isle is considered one of the windiest lowland sites in the British Isles. For this reason, some monads were difficult to survey (top of Ward Hill, Burrashield). However, a best effort was made to record across the island. Yet future work should make contingency plans in case of bad weather. 47
5. Conclusion
This project aimed to compile the presence of all vascular plants on Fair Isle, a remote and isolated Scottish island located halfway between Orkney and Shetland. The best approach to achieve the above was through a floristic survey of the nineteen monads (1km2) that forms Fair Isle, by recording presence and absence of plant species. Even though the survey period was limited to June 2016, some species on the island are likely to have been missed due to the late flowering time.
A large amount of data was collected representing the distribution of 238 plant species along the island, resulting in 27 orders, 59 families and 116 genera. Of the total number of species found, there are 27 introduced and the rest 211 species are native to the British Isles.
At the same time that plant species were being recorded, habitats were described by a general walkover survey. It is important to highlight this distinction in the methodology used for the habitat survey, because the results are not meant to be conclusive but a baseline for further research. Nevertheless, the presence of 9 habitats over the small surface area (768 hectares) of Fair Isle is an important result, and compares favourably with the 15 habitats described across the much larger area of Shetland in the literature. An attempt to know the possible NVC communities on Fair Isle revealed the presence of 16 of them. Even though these classifications can be allocated to the habitats surveyed by checking floristic NVC tables and comparing with the species found in the habitats of Fair Isle, their low match value suggest that are not well covered in the published NVC communities. It may be that Fair Isle has distinct communities different to the rest of the British Isles.
After having the results of the floristic survey plus the habitat description, and in comparison with other islands and historical records, it is satisfying to state that the flora of Fair Isle is indeed surprisingly diverse. It appears that the diversity of habitats gives home to a considerable number of species.
It is hope that this research project could be taken by future researchers as a significant baseline to focus on the conservation of those species under threat and those that are nationally scarce.
48
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7. Appendix
Appendix 1 Check list of the species found during the month of June classify by division, order and family according to APG IV (Byng et al., 2016)
Division Genus Species Author Pteridophyta Asplenium marinum L. Pteridophyta Athyrium filix-femina (L.) Roth Pteridophyta Blechnum spicant (L.) Sm. Pteridophyta Botrychium lunaria (L.) Sw. Pteridophyta Dryopteris dilatata (Hoffm.) A. Gray Pteridophyta Dryopteris filix-mas (L.) Schott Pteridophyta Equisetum arvense L. Pteridophyta Equisetum palustre L. Pteridophyta Hymenophyllum wilsonii Hook. Pteridophyta Ophioglossum azoricum C. Presl Pteridophyta Polypodium vulgare L. Pteridophyta Pteridium aquilinum (L.) Kuhn Lycophyta Huperzia selago (L.) Bernh. ex Schrank & Mart. Lycophyta Selaginella selaginoides (L.) P. Beauv. ex Mart. & Schrank Gymnosperms Abies sp. Mill. Gymnosperms Juniperus communis subsp. nana (Willd.) Syme Gymnosperms Picea sitchensis (Bong.) Carrière Ang. Monocot Agrostis canina L. Ang. Monocot Agrostis capillaris L. Ang. Monocot Agrostis stolonifera L. Ang. Monocot Agrostis vinealis Schreb. Ang. Monocot Aira praecox L. Ang. Monocot Alopecurus geniculatus L. Ang. Monocot Alopecurus pratensis L. Ang. Monocot Anthoxanthum odoratum L. Ang. Monocot Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl Ang. Monocot Avena strigosa Schreb. Ang. Monocot Carex bigelowii Torr. ex Schwein. Ang. Monocot Carex binervis Sm. 53
Division Genus Species Author Ang. Monocot Carex viridula subsp. oedocarpa (Andersson) B. Schmid Ang. Monocot Carex dioica L. Ang. Monocot Carex echinata Murray Ang. Monocot Carex flacca Schreb. Ang. Monocot Carex hostiana DC. Ang. Monocot Carex nigra (L.) Reichard Ang. Monocot Carex viridula subsp. viridula Michx. Ang. Monocot Carex panicea L. Ang. Monocot Carex pilulifera L. Ang. Monocot Carex pulicaris L. Ang. Monocot Coeloglossum viride (L.) Hartm. Ang. Monocot Crocosmia x crocosmiiflora (Lemoine ex Anonymous) N.E. Br. Ang. Monocot Cynosurus cristatus L. Ang. Monocot Dactylis glomerata L. Ang. Monocot Dactylorhiza incarnata (L.) Soó Ang. Monocot Dactylorhiza maculata (L.) Soó Ang. Monocot Dactylorhiza purpurella (T. Stephenson & T.A. Stephenson) Soó Ang. Monocot Danthonia decumbens (L.) DC. Ang. Monocot Deschampsia cespitosa (L.) P. Beauv. Ang. Monocot Deschampsia flexuosa (L.) Trin. Ang. Monocot Eleocharis palustris (L.) Roem. & Schult. Ang. Monocot Eleocharis quinqueflora (Hartmann) O. Schwarz Ang. Monocot Eleogiton fluitans (L.) Link Ang. Monocot Elytrigia repens (L.) Desv. ex Nevski Ang. Monocot Eriophorum angustifolium Honck. Ang. Monocot Eriophorum vaginatum L. Ang. Monocot Festuca rubra L. Ang. Monocot Festuca vivipara (L.) Sm. Ang. Monocot Glyceria fluitans (L.) R. Br. Ang. Monocot Holcus lanatus L. Ang. Monocot Hyacinthoides x massartiana Geerinck Ang. Monocot Iris pseudacorus L. Ang. Monocot Juncus articulatus L. Ang. Monocot Juncus bufonius L. Ang. Monocot Juncus bulbosus L. 54
Division Genus Species Author Ang. Monocot Juncus conglomeratus L. Ang. Monocot Juncus effusus L. Ang. Monocot Juncus gerardii Loisel. Ang. Monocot Juncus squarrosus L. Ang. Monocot Lolium perenne L. Ang. Monocot Luzula campestris (L.) DC. Ang. Monocot Luzula multiflora (Ehrh.) Lej. Ang. Monocot Luzula sylvatica Gaudin Ang. Monocot Molinia caerulea (L.) Moench Ang. Monocot Narcissus sp. L. Ang. Monocot Nardus stricta L. Ang. Monocot Narthecium ossifragum (L.) Huds. Ang. Monocot Neottia cordata (L.) Rich. Ang. Monocot Phalaris arundinacea L. Ang. Monocot Phleum pratense L. Ang. Monocot Poa annua L. Ang. Monocot Poa humilis Ehrh. ex Hoffm. Ang. Monocot Poa trivialis L. Ang. Monocot Potamogeton polygonifolius Pourr. Ang. Monocot Puccinellia distans subsp. borealis (Holmb.) W.E. Hughes Ang. Monocot Schoenus nigricans L. Ang. Monocot Scilla verna Huds. Ang. Monocot Trichophorum cespitosum (L.) Hartm. Ang. Monocot Trichophorum germanicum Palla Ang. Monocot Triglochin palustris L. Ang. Eudicot Acer pseudoplatanus L. Ang. Eudicot Achillea millefolium L. Ang. Eudicot Achillea ptarmica L. Ang. Eudicot Aegopodium podagraria L. Ang. Eudicot Alchemilla mollis (Buser) Rothm. Ang. Eudicot Anagallis tenella (L.) L. Ang. Eudicot Anchusa arvensis (L.) M. Bieb. Ang. Eudicot Angelica sylvestris L. Ang. Eudicot Antennaria dioica (L.) Gaertn. Ang. Eudicot Anthyllis vulneraria L. 55
Division Genus Species Author Ang. Eudicot Apium inundatum Rchb. f. Ang. Eudicot Armeria maritima (Mill.) Willd. Ang. Eudicot Aster x salignus Willd. (pro sp.) Ang. Eudicot Atriplex glabriuscula Edmondston Ang. Eudicot Atriplex patula L. Ang. Eudicot Atriplex sp. L. Ang. Eudicot Ballota nigra L. Ang. Eudicot Bellis perennis L. Ang. Eudicot Cakile maritima Scop. Ang. Eudicot Callitriche sp. L. Ang. Eudicot Callitriche stagnalis Scop. Ang. Eudicot Calluna vulgaris (L.) Hull Ang. Eudicot Caltha palustris L. Ang. Eudicot Capsella bursa-pastoris (L.) Medik. Ang. Eudicot Cardamine flexuosa With. Ang. Eudicot Cardamine pratensis L. Ang. Eudicot Centaurea nigra L. Ang. Eudicot Cerastium diffusum Pers. Ang. Eudicot Cerastium fontanum Baumg. Ang. Eudicot Cirsium arvense (L.) Scop. Ang. Eudicot Cirsium vulgare (Savi) Ten. Ang. Eudicot Cochlearia danica L. Ang. Eudicot Comarum palustre L. Ang. Eudicot Drosera rotundifolia L. Ang. Eudicot Empetrum nigrum L. Ang. Eudicot Epilobium ciliatum Raf. Ang. Eudicot Epilobium palustre L. Ang. Eudicot Erica cinerea L. Ang. Eudicot Euphorbia helioscopia L. Ang. Eudicot Euphrasia arctica Lange ex Rostr. Ang. Eudicot Euphrasia micrantha Rchb. Ang. Eudicot Euphrasia nemorosa (Pers.) Wallr. Ang. Eudicot Euphrasia confusa Pugsley Ang. Eudicot Euphrasia foulaensis F. Towns. ex Wettst. Ang. Eudicot Euphrasia scottica Wettst. 56
Division Genus Species Author Ang. Eudicot Euphrasia sp. L. Ang. Eudicot Euphrasia ostenfeldii (Pugsley) Yeo Ang. Eudicot Fallopia japonica (Houtt.) Ronse Decr. Ang. Eudicot Ficaria verna Huds. Ang. Eudicot Filipendula ulmaria (L.) Maxim. Ang. Eudicot Galeopsis bifida Boenn. Ang. Eudicot Galeopsis tetrahit L. Ang. Eudicot Galium aparine L. Ang. Eudicot Galium palustre L. Ang. Eudicot Galium saxatile L. Ang. Eudicot Gentianella campestris (L.) Börner Ang. Eudicot Glaux maritima L. Ang. Eudicot Gnaphalium uliginosum L. Ang. Eudicot Hydrocotyle vulgaris L. Ang. Eudicot Hypericum pulchrum L. Ang. Eudicot Hypochaeris radicata L. Ang. Eudicot Jasione montana L. Ang. Eudicot Lamium confertum Fr. Ang. Eudicot Lamium purpureum L. Ang. Eudicot Lathyrus pratensis L. Ang. Eudicot Leucanthemum vulgare Lam. Ang. Eudicot Ligusticum scoticum L. Ang. Eudicot Linum catharticum L. Ang. Eudicot Littorella uniflora Asch. Ang. Eudicot Lonicera sp. L. Ang. Eudicot Lotus corniculatus L. Ang. Eudicot Matricaria discoidea DC. Ang. Eudicot Mentha aquatica L. Ang. Eudicot Mentha x piperita L. Ang. Eudicot Mertensia maritima (L.) Gray Ang. Eudicot Montia fontana L. Ang. Eudicot Myosotis arvensis (L.) Hill Ang. Eudicot Myosotis laxa Lehm. Ang. Eudicot Myriophyllum alterniflorum DC. Ang. Eudicot Pedicularis sylvatica L. 57
Division Genus Species Author Ang. Eudicot Persicaria amphibia (L.) Delarbre Ang. Eudicot Persicaria bistorta (L.) Samp. Ang. Eudicot Persicaria maculosa Gray Ang. Eudicot Persicaria vivipara (L.) Ronse Decr. Ang. Eudicot Pinguicula vulgaris L. Ang. Eudicot Plantago coronopus L. Ang. Eudicot Plantago lanceolata L. Ang. Eudicot Plantago major L. Ang. Eudicot Plantago maritima L. Ang. Eudicot Polygala serpyllifolia Hose Ang. Eudicot Polygonum arenastrum Boreau Ang. Eudicot Polygonum boreale (Lange) Small Ang. Eudicot Potentilla anserina L. Ang. Eudicot Potentilla erecta (L.) Raeusch. Ang. Eudicot Primula vulgaris Huds. Ang. Eudicot Prunella vulgaris L. Ang. Eudicot Radiola linoides Roth Ang. Eudicot Ranunculus acris L. Ang. Eudicot Ranunculus flammula L. Ang. Eudicot Ranunculus hederaceus L. Ang. Eudicot Ranunculus repens L. Ang. Eudicot Rhinanthus minor L. Ang. Eudicot Ribes sp. L. Ang. Eudicot Rosa rugosa Thunb. Ang. Eudicot Rubus spectabilis Pursh Ang. Eudicot Rumex acetosa L. Ang. Eudicot Rumex acetosella L. Ang. Eudicot Rumex crispus L. Ang. Eudicot Rumex longifolius DC. Ang. Eudicot Rumex obtusifolius L. Ang. Eudicot Sagina maritima G. Don Ang. Eudicot Sagina procumbens L. Ang. Eudicot Sagina subulata d'Urv. Ang. Eudicot Salix herbacea L. Ang. Eudicot Salix repens L. 58
Division Genus Species Author Ang. Eudicot Salix sp. L. Ang. Eudicot Scorzoneroides autumnalis Moench Ang. Eudicot Sedum rosea (L.) Scop. Ang. Eudicot Senecio aquaticus Hill. Ang. Eudicot Senecio smithii DC. Ang. Eudicot Senecio vulgaris L. Ang. Eudicot Silene dioica (L.) Clairv. Ang. Eudicot Silene flos-cuculi (L.) Greuter & Burdet Ang. Eudicot Silene uniflora Roth Ang. Eudicot Sonchus arvensis L. Ang. Eudicot Sonchus asper (L.) Hill Ang. Eudicot Sorbus aria (L.) Crantz Ang. Eudicot Sorbus sp. L. Ang. Eudicot Spergula arvensis L. Ang. Eudicot Spergularia marina (L.) Besser Ang. Eudicot Spergularia media (L.) C. Presl Ang. Eudicot Stellaria alsine Grimm Ang. Eudicot Stellaria media (L.) Vill. Ang. Eudicot Succisa pratensis Moench Ang. Eudicot Symphytum x uplandicum Nyman Ang. Eudicot Taraxacum sp. F.H. Wigg. Ang. Eudicot Thymus polytrichus A. Kern. ex Borbás Ang. Eudicot Trientalis europaea L. Ang. Eudicot Trifolium pratense L. Ang. Eudicot Trifolium repens L. Ang. Eudicot Tripleurospermum maritimum (L.) W.D.J. Koch Ang. Eudicot Tussilago farfara L. Ang. Eudicot Ulex gallii Planch. Ang. Eudicot Urtica dioica L. Ang. Eudicot Vicia cracca L. Ang. Eudicot Vicia sepium L. Ang. Eudicot Viola canina L. Ang. Eudicot Viola palustris L. Ang. Eudicot Viola riviniana Rchb.
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A CD with appendices is provided. Files are as follows: Appendix 2 Map for recording of individual monads (“Monads- Fair Isle.pdf”) Appendix 3 BSBI recording cards for vice county 112, Shetland (“BSBI recording cards VC112.pdf”) Appendix 4 Floristic tables for each monad and habitat.xlsx Appendix 5 TWINSPAN species codes.xlsx Appendix 6 Species found as new, extinct, mistaken, synonyms and doubtful situation (“Additional species.docx”)