Dead Wood Comes Alive
Transcription
Dead Wood Comes Alive
Article Dead Wood Comes Alive Research into cryptogamic diversity of beech forests across Europe led to a visit to Epping Forest for the authors Erik Aude, Klaas van Dort, Rasmus Fuglsang rMap 1. European beech areas (in green, data EUFORGEN) and sites visited by Beech Boys (red dots). M. Christensen Frederiksen and Sally Gadsdon, who report on the groups findings. and Sweden (see Map 1). In addition to dead wood communities, the epiphytic flora of the sites was studied. The research is trying to disentangle biodiversity patterns with regards to bryophytes, fungi and lichens growing on dead wood and old trees on a European scale. More specifically, whether the influences of long term history, climate and human impact can be discerned on the biodiversity patterns of these taxa. Sites were selected across Europe to cover as wide a climatic gradient within the distribution of beech forests as possible. Over the last 10 years the Beech Boys have visited almost 100 forest reserves in Europe. Of the Beech Boys, Erik Aude, Klaas van Dort and Rasmus Fuglsang Frederiksen were responsible for recording bryophytes (and lichens!). rFig. 1 The Beech Boys (& girl!) at Burnham Beeches. Sitting on beech log: (left to right) Claus Baessler, Klaas van Dort, Erik Aude, Nerea Abrego Antia, Örjan Fritz. In front of beech log: (left to right) Morten Christensen, Martyn Ainsworth (guest Beech Boy), Rasmus Fuglsang Frederiksen. M. Christensen W hilst many people dream of working in nature conservation, even those working at a European renowned site can forget just how a special place it is. In this case it is Epping Forest which lies across the boundary of Essex and Greater London. Being a well-known site, it often receives national and international visitors. In 2014 a group of European ecologists visited the site as part of a project studying the cryptogamic flora of dead beech wood. Other sites they included in their visit to Britain were the New Forest (Denny Wood and Wood Crates), Savernake (Wiltshire), Lady Park Wood (Gloucestershire/ Monmouthshire) and Burnham Beeches (Buckinghamshire). The project background This visit was part of on-going research into beech woodlands. It started with research into 26 FieldBryology No113 | May 15 the diversity of dead wood inhabiting species in many of the best preserved beech forests in Belgium, Denmark, England, Hungary, Slovenia and The Netherlands. This was funded by the European Community as part of the Nat-Man project (Nature-based Management of beech in Europe) and it finished in 2005. From this some enthusiastic experts on cryptogams continued recording inventories in beech dominated ancient woodlands on a voluntary basis, under the name of “the Beech Boys” (beechboys.eu). Yes, pun intended. The original core of the Beech Boys survives and people join the group for one or several years, with new members welcome. Between 2005 and 2014 the Beech Boys have systematically collected data on species composition of epixylic communities in ancient woodland reserves in Austria, Bulgaria, Croatia, Czech Republic, Germany, Italy, Slovakia, Spain The visit to Britain The British sites were visited in late October 2014. Local managers and administrators warmly welcomed the group at the various sites. During the trip the Beech Boys were joined by Martyn Ainsworth, fungi expert from Kew Gardens. In Wales George Peterken, the wellknown conservationist of natural woodlands, showed them ‘his’ Lady Park Wood. The group enjoyed their short trip to England, not least as “the exploitation of local food and drinks made the trip very rewarding indeed”. In general, dead wood specialists were very poorly represented at all sites. Most beech logs showed the effects of black rot fungi (Eutypa spinosa), which makes the wood hard and creates a very unfavourable substratum for epixylic bryophytes. As was to be expected the epiphytic lichen flora was very good in the New Forest, Wood Crates being among the “best” beech forests in Britain with many species of conservation concern, several figuring in Rose’s Revised Index of Ecological Continuity list (Coppins & Coppins, 2002). The remaining four sites were extremely poor. Beech stems in Burnham Beeches and Epping Forest were almost devoid of epiphytes, even nitrogen loving ones were scarce (but abundant on trees in gaps and along the forest edge). A preliminary list of the species found on beech logs and wind-thrown root-balls at Epping is given below (Table 1, FieldBryology No113 | May15 27 FieldBryology No113 | May 15 bryophyte Zygodon viridissimus Lophocolea bidentata What’s the outcome? One of the main aims is to produce illustrated manuals on cryptogamic indicator species dependent on dead beech wood. There will be three volumes, the first dealing with bryophytes, the second focusing on fungi, and the third will be on all epiphytes as ancient woodland indicators in (semi) natural European beech woodlands. These manuals are aimed at forest managers, staff at national parks and forest reserves, as well as people interested in cryptogams in general. Several scientific papers on the subject have already been published (see references) and there are more to follow (will be listed on beechboys. eu). The future In 2015 the Beech Boys are preparing for a trip to Romania. In the future, a visit is planned to the important Ukrainian reserves, among which is the vast Uholka forest, the largest virgin beech forest in Europe and a UNESCO world heritage site. Also the best sites of Germany and France, including the famous La Tilleul reserve rFig. 2. Klaas surveying beech dead wood in Epping Forest. S. Gadsdon at Fontainebleau, await further investigation. After this there will be more data analysis to complete, so the manuals are several years off publication. But for this one day, we knew that a little part of Epping Forest had had a thorough bryological going-over! And we remembered that Epping Forest is very special. sFig. 3. Erik, Klaas and Rasmus worshiping at the altar of Zygodon forsteri. S. Gadsdon Dicranoweisia cirrata bryophyte bryophyte bryophyte Zygodon conoideus Zygodon forsteri lichen Leucobryum glaucum lichen Cladonia fimbriata Lepraria lobificans lichen Cladonia coniocraea Kindbergia praelonga Lepraria incana bryophyte Cephalozia bicuspidata Candelaria concolor lichen bryophyte bryophyte bryophyte bryophyte Ulota bruchii Ulota crispa bryophyte lichen bryophyte bryophyte Rhizomnium punctatum Thuidium tamariscinum bryophyte some species still awaiting identification). But the trip to Epping Forest was not without a highlight, Erik, Klaas and Rasmus were taken to a nearby patch of Forster’s Knothole Moss Zygodon forsteri, (Fig. 3). Epping Forest has the largest population of Z. forsteri in the UK with 158 known colonies on 77 trees (2008 survey, 28 Adams 2008). Burnham Beeches and the New Forest are the only other two UK sites where this beech specialist can be found. It has fairly specific habitat requirements, only being found on parts of the tree which are regularly wet or hold water such as root knotholes or stemflow routes. This was a new species for both Erik and Rasmus. Klaas said “according to literature Zygodon forsteri is widespread, but rare, in Europe, ranging from eastern Bulgaria to western Portugal and from southern Spain as far north as Denmark. Interesting is the shift in sporophytes throughout its range. Fagus sylvatica is by far the commonest host in the north, several species of Quercus are used in the southern part of its range, where beech reaches its southern limits. Before Sally Gadsdon showed it to us I had seen it only once, in Basaula, a small forest reserve occupying a sheltered canyon in the foothills of the Sierra de Urbasa (Navarra). It was abundantly fruiting and easily spotted on several stems of Quercus faginea and Quercus ilex. The wet rim of rot holes is the usual microhabitat to look for it. In Spain it grows well above the ground, e.g. where branches have broken off from the stem, quite unlike its usual habitat in England where root systems at ground level seem to be preferred. Zygodon forsteri is also known from Fontainebleau. Thanks to our field training in Epping we are quite confident to spot it there too!” bryophyte Hypnum cupressiforme Isothecium myosuroides bryophyte bryophyte Campylopus introflexus lichen Porina aenea bryophyte Hypnum andoi bryophyte Calypogeia arguta Campylopus flexuosus lichen bryophyte Polytrichum formosum bryophyte Herzogiella seligeri Bryum flaccidum bryophyte Physcia tenella Frullania dilatata Brachythecium velutinum bryophyte bryophyte bryophyte bryophyte Mnium hornum Orthotrichum affine bryophyte Fissidens taxifolius bryophyte Brachythecium salebrosum Fissidens bryoides Brachythecium rutabulum bryophyte bryophyte bryophyte bryophyte Lophocolea heterophylla Metzgeria furcata bryophyte bryophyte Eurhynchium striatum bryophyte Atrichum undulatum Dicranum scoparium lichen Arthonia spadicea Table 1. Preliminary species list for species found on beech logs and wind-thrown root-balls at Epping Forest (some species still awaiting identification). Dead Wood Comes Alive FieldBryology No113 | May15 29 Article wFig. 3. Tubers of Pleuridium acuminatum (10 divisions of scale = 100 µm) N.J. Law Rhizoidal tubers in Pleuridium acuminatum Nick Law and Tom Blockeel report the discovery of rhizoidal tubers in this moss in Britain in a stubble field in South Derbyshire rFig. 4 (left). Zygodon forsteri (darkest green moss) growing on a beech root knothole. S. Gadsdon. rFig. 5 (right). Zygodon forsteri. K. Adams Adams, K. (2008). The status and distribution of the Schedule 8 Red Data moss Zygodon forsteri (With.) Mitt. In Epping Forest. A report for the City of London. & Christensen, M. (2005). Diversity and composition of dead wood inhabiting bryophyte communities in European beech forests. Boletín de la Sociedad Española de Briología 2627: 85-102. Coppins, A. M. & Coppins, B. J. (2002). Indices of Ecological Continuity for Woodland Epihytic Lichen Habitats in the British Isles. British Lichen Society. Spier, L., van Dort., K., Fritz, Ö. (2008). A contribution to the lichen mycota of old beech forests in Bulgaria. Mycologia Balcanica 5: 141-146. References EUFORGEN. European Forest Genetic Resources Programme. Distribution maps. www.euforgen.org/distribution-maps/ Heilmann-Clausen, J., Aude, E., van Dort, K., Christensen, M., Piltaver, A., Veerkamp, M., Walleyn, R., Siller, I., Standovar, T. & Ódor, P. (2014). Communities of woodinhabiting bryophytes and fungi on dead beech logs in Europe – reflecting substrate quality or shaped by climate and forest history? Journal of Biogeography, doi: 10.1111/ jbi.12388 Ódor, P., Heilmann-Clausen, J., Christensen, M., Aude, E., van Dort, K. W., Piltaver, A., Siller, I., Veerkamp, M. T., Walleyn, R., Standovar, T., van Hees, A. F. M., Kosec, J., Matocec, N., Kraigher, H. & Grebenc, T. (2006). Diversity of dead wood inhabiting fungal and bryophyte assemblage in semi-natural beech forests in Europe. Biological Conservation 131: 58-71. Ódor, P., van Dort, K. W., Aude, E., Heilmann-Clausen, J. 30 FieldBryology No113 | May 15 Erik Aude, Consultant Bryologist and owner, HabitatVision, (www.habitatvision.dk), Denmark e eau@habitatvision.dk Klaas van Dort, Consultant Bryologist and owner, Forestfun, The Netherlands e klaasvandort@online.nl Rasmus Fuglsang Frederiksen, Consultant Bryologist and owner, VINK, Denmark e rasmusfuglsangfrederiksen@gmail.com Sally Gadsdon, Environmental Stewardship Officer, Epping Forest, City of London e sally.gadsdon@cityoflondon.gov.uk R Introduction isse (1987) provided a review of the published knowledge of tubers (rhizoidal gemmae) in mosses from the time of their probable first description by T.F.L. Nees von Esenbeck in 1818 up to March 1987. This review encompassed key papers such as that by Whitehouse (1966), which described and illustrated the rhizoidal tubers of twenty-nine species of European mosses. Risse’s review (1987) listed 82 European mosses and 36 extra-European mosses from which tubers had been confirmed. Neither of these lists included Pleuridium acuminatum although, as noted by Risse, H. Koch had long before reported the occurrence of tubers within the genus (Koch, 1842). Their occurrence within European populations of P. acuminatum was confirmed by Arts & Risse (1988), following the discovery by R. Düll in 1986 of a tuber-bearing herbarium specimen of P. acuminatum, collected by F. Neu and originally determined as P. subulatum. Arts & Risse detected rhizoidal tubers in 11 out of 15 specimens of P. acuminatum but were unable to find them in 28 specimens of P. subulatum that they examined. Smith (2004) indicates that rhizoidal tubers sometimes occur in P. acuminatum and provides a description of them, but he does not indicate whether this observation is based on material from Britain or continental Europe, and he does not illustrate the tubers. Porley (2008) stated that “large, brown, variably-shaped tubers, surrounded by a hyaline layer, occur commonly on continental specimens of P. acuminatum but have not been reported in the British Isles and should be looked out for”. He provided a photomicrograph of a tuber from a Portuguese specimen. Finch & Blockeel (in Blockeel et al., 2014) also highlight the frequency of rhizoidal tubers on continental specimens and suggest that they ‘…doubtless occur in Britain’. Pleuridium species in arable land Both P. acuminatum and P. subulatum occur within arable fields but P. acuminatum appears to do so less frequently according to the results of the Survey of Bryophytes on Arable Land FieldBryology No113 | May15 31