Fen Orchid Liparis Loeselii Reintroduction Strategy – V 2013
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Fen Orchid Liparis loeselii Reintroduction strategy – V 2013 Note: This is a highly confidential document not to be shared without prior permission from Mr Tim Pankhurst. Background The purpose of the current conservation programme is to generate a coherent reintroduction strategy that has a high probability of success; success is important as all introduction sites must be monitored and a considerable amount of time and resources can be wasted monitoring sites that have failed. It is recognised that introductions are most likely to work if introduced plants are mature; the time taken to generate a decent stock of mature plants allows for several years within which to devise a robust reintroduction strategy that is founded on an in-depth understanding of the needs of the plant and in which to properly assess the suitability of all potential reintroduction sites. The conservation programme, as of 2010, is outlined below: 1. Annual surveillance of the surviving populations of Liparis loeselii. 2. Experimental research This is comprised of two elements: a. Seed-baiting. Aimed at germinating seeds which can be isolated: benefits are: i. The fungal symbiont can be isolated and identified ii. Liparis germinands can be cultivated and grown on iii. Slides can be set out in such a way as to determine the distribution of the fungal symbiont Identification of the fungi that can form a symbiotic bond with Liparis will potentially enable the suitability of sites for the plant to be assessed by field mycologists. Its isolation and ex-situ cultivation will enable Liparis stock to be generated in the lab; Liparis stock is required both for the generation of large numbers of mature plats for potential reintroductions buut also for ex-situ ecological studies. b. Dispersal research. One of the issues in the conservation of Liparis is the level of importance for the plant of its ability to disperse and take advantage of new opportunities. Dispersal manifestly occurs as seed, both through the air and across water, but plants may also be adapted to disperse as mature growing entities; this ability obviates the need for presence of the fungal symbiont as germination is not required. Vegetative dispersal is intimately allied with vegetative propagation and both of these aspects of Liparis ecology are to be studied through a combination of ex-situ work at CUBG and in-situ experiments as circumstances allow. However, understanding changes as new facts come to light and the above programme has had to be modified: 1 One fungal symbiont has been identified to genus. There may be other species and genera involved. Sites may however still be assessed for presence of fungi without symbiont id. The success rate for seed-baiting is however very low – hundreds of traps may be put out with no positive returns – so a negative result does not indicate the absence of the symbiont. The process also takes 18 months or so. Accordingly, given the information, site reintroductions should not be constrained by negative or absent returns from seed baiting. Presence of fungal symbiont is not now considered essential but helpful for reintroduction site suitability – see below. Vegetative reproduction is proven; this process generates small groups of clonally generated material around parent plants. More evidence has been gathered to show the presence of vegetative dispersal, at least within management units. Reintroduction site suitability must therefore be assessed for the presence of suitable processes to facilitate this reproductive activity; if such processes are present, then site does not require presence of fungal symbiont. Presence of both is desirable Site Assessment The strategy therefore rests on the suitability of sites for reintroduction based upon: the current vegetation being appropriate, and subject to appropriate hydrological influences the presence of appropriate conservation management either o presence of processes that may stimulate vegetative dispersal or… o the presence of fungal symbiont, but preferably both. date of last record, the most recent records according greater priority to the site. Sites that sit high on the table on the first three grounds and have a recent last record are considered for assessment for fungal symbiont, which is a time-consuming and lengthy process. A manageable programme of seed- baiting for site assessment will be undertaken with the programme moving down the list as sites are either confirmed to have the symbiont or fail to qualify for whatever reason. Sites are not at the moment being considered for pure introduction. Below is a list of former sites with notes about their history, status and fate of Liparis there: 2 Former sites The information below is abstracted and updated from Land R. 1998 Ecology of Liparis loeselii: Unpublished report. Blo' Norton Fen TM 025787 SSSI Liparis was recorded between 1911 - 1956 "in the floating bogs at Blo’ Norton". In 1956 only 1 plant was seen (NCC site History Dossier). The site had succeeded to mature alder and willow scrub but from 1998 has been undergoing restoration; it now contains c. 1 ha of mown, species-rich fen vegetation. Bottisham Fen c. TL5561 no location Last record 1835. Site probably drained and destroyed Burwell/Reach Fen TL5666 Last record 1842. Site drained and destroyed Calthorpe Broad, Harvey's Marsh TG 412258 SSSI Robert Gurney reports citing 2 plants in 1924, however they could not be found the following year or since. Chippenham Fen TL 647692 SSSI/NNR Last record 1928. Whole site manged for nature conservation and yet supports large areas of species-rich fen vegetation. However, the whole site is degraded by water abstraction which is still an issue, and many species have been lost. Dilham, Broad Fen TG 343253 SSSI The southern part overlies the basin of Dilham Broad, a former peat cutting. Much of the botanical interest has been lost to scrub, with some reversal due to recent management. Until the late 1950's it supported a thriving Liparis community which is now extinct as a result of successional change to scrub and dessication. Abstraction in the surrounding 2 km area removes 33 million gallons per year. In the 1950's it was reported as "... open fen supporting a wide assemblage of flowering herbs and bryophytes... Liparis grew in abundance... a small area of rich mixed fen with an imposing species list and very interesting community structure." In 1958 burning and cutting and removal of alder carr resulted in regeneration of Schoenus-Juncus subnodulosus fen with Liparis, the clearance and regular mowing and burning of litter appears to have produced good conditions for Liparis and apparantly small pools were also created. By the 1980's it had degraded through lack of management over the past 20 years. In 1983 turf ponds were created and clearance of scrub began again. In 1991 abstraction appeared to be affecting the site. Liparis was found in the northern end of the site until the late 1950's (Parmenter1993). It was this northern area that has been particularly affected by abstraction. The turf ponds were cut on the site of an old 3 basin, but it is not thought that Liparis actually occurred in that area (Lambley pers comm). East Ruston, King's Fen TG 343283 SSSI A valley fen and former site for peat digging. The site was grazed extensively and the common used for producing hay, reed and rush. Once these practices died out scrub invaded but more serious changes have occured from abstraction with a licence to remove 226 million gallons from boreholes and wells in a 2 km radius. Ninety-eight percent comes from a borehole only 100m from the southern boundary of the fen. Burning in the 70's and 80's has also been a problem. By the mid 80's dessication was causing a problem to various plant communities and creating changes. "On the valley floor the mixed fen with abundant Peucedanum has given way to reed, nettle, bramble, Calamagrostis... and Epilobium...the peat surface is very dry and puffy to walk on and is clearly oxidising". In the late ‘90’s the site underwent restorative management which involved the removal of large quantities of oxidised peat and the creation of small shallow lakes which are colonising with fen vegetation. Liparis loeselii occured on the site in the more alkali areas near Hundred stream (Parmenter 1993). East Ruston Mown Fen TG 341275 SSSI A valley fen and part of East Ruston Common, the fen itself overlays large 19th century peat cuttings along the stream. Cutting ceased in the 1920's and these became terrestrialised, providing hay, reed sedge, rush and some grazing. Discontinuation of these practices has allowed successional processes to proceed but the site has been seriously affected by water abstraction with 226 million gallons removed within a 2 km radius of the site and most abstracted within 50 metres of the northern boundary. In the late ‘90’s the site underwent restorative management which involved the removal of large quantities of oxidised peat and the creation of small shallow lakes which are colonising with fen vegetation. Records for the site are extensive because of its botanical interest. Liparis recored on the site and thought to occur in the more alkali areas near Hundred stream. Dates are: 1918. (Parmenter 1993.) Fordham Fen TL66/67 location unknown. Last known 1896. Site probably drained and destroyed. Fulbourn Moor TL 529560 SSSI Last record 1820. This site still supports species-rich vegetation but has declined due to drainage over many decades. The fen vegetation here has changed to one of wet grassland and many species have been lost. It has however still managed as a nature reserve by the Cambridgeshire Wildlife Trust 4 Hinton Moor TL45 No location Last known 1806.