A SCIENTIFIC APPROACH to a POLICY on COMMERCIAL COLLECTING of WILD FUNGI the Need for the British Mycological Society to Tion of Fruiting Bodies
Total Page:16
File Type:pdf, Size:1020Kb
Volume 11,Part 2, May 1997 A SCIENTIFIC APPROACH TO A POLICY ON COMMERCIAL COLLECTING OF WILD FUNGI The need for the British Mycological Society to tion of fruiting bodies. Recent experimental develop a policy on commercial collecting of work in Scandinavian forests reported by fungi was outlined in Mycologist 11, pp 27-28. Brandrud (1995) shows dramatic reductions of This paper aims to provide an overview of the fungal fruiting bodies as a result of nitrogen scientific arguments and research results on the enrichment. viability of large-scale harvesting and assess the The picture which emerges from current implications for wildlife conservation policy. The research in continental Europe is one of falling primary concern is the long-term survival of col- yields due to habitat loss, farming and forestry lected species and the consequential effect on changes, pollution, and recreational pressure. habitats and dependent organisms. Increasing pressure from collecting is focused on this diminishing resource. The science and research results The conservation issue directly concerns the Harvesting fungi only involves collecting the long-term viability of species, not falling yields. fruiting body, leaving the mycelium in the soil. The factors which govern the establishment of For some mycorrhizal species the mycelia are new mycelia and the colonisation of new sites in known to survive for very long periods, perhaps the wild are very complex. It is a striking feature centuries. The majority of commercially collect- of most fungi that they produce millions of ed species are mycorrhizal and many are still rel- spores. Agaricus campestris, for example, may atively abundant: Boletus edulis, Cantharellus liberate 500,000 spores per minute over several cibarius and Lactarius deliciosus are all widely days. The wastage rate is clearly enormous and distributed in Europe. This would appear to be a the chances of establishing new mycelia are like- good model of a sustainable yield system; howev- ly to be very low, even where there are huge er, Arnolds (1991) reports strong evidence for numbers of spores available. Reductions in declining yields from a number of such species spore numbers, from whatever cause, will reduce across Europe. the chances of reproductive success. Well designed field experiments have been Rare species of fungi may be particularly vul- undertaken by Simon Egli and Francois Ayer nerable to removal of fruiting bodies. Those (Egli, 1995) for the Swiss Institute of Forestry, that occur late in the forest cycle associated with and by Notvell (1996) for the Oregon Mycological old trees of fragmented habitats such as heath- Society. The aim of both studies, conducted lands are most likely to be in this category. over ten years, was to determine the effects of Although few of these, other than Hydnum spp, intensive harvesting on the yield of are commercially collected there is some evi- macromycetes. The results show clearly that dence that unskilled commercial pickers collect harvesting itself has no significant effect. indiscriminately; for example those collecting However, Egli showed that trampling did signifi- Boletus edulis may collect all boletes. These are cantly reduce yields, possibly through soil com- then sorted and graded at the purchaser's paction. This finding could have important premises where the inedible, possibly rare, implications. species are then discarded. This practice may Many factors other than large-scale collecting directly impair the establishment of mycelia at affect the viability of fungi: habitat loss, changing new sites. We have found no valid research on farming and forestry practices and pollution are this topic. the main concerns. Research on habitat loss is Removal of fruit bodies also affects those now extensive throughout Western Europe. organisms that live on fungi, particularly those Many commercially collected species of fungi wholly dependent on particular species as a occur in rapidly declining habitats, and semi-nat- source of food. Alexander et al (1996) cite certain ural and forested areas cover a far lower propor- fungi as an essential breeding medium for a large tion of the land surface in Britain and Eire than range of invertebrates, including many rare and in most other European countries. The use of threatened species. exotic tree species in afforestation schemes, large single-species plantations and clear felling prac- Discussion tices have all affected fungi. Rotheroe et al It is the combined effects of all these pressures (1996) refer to the fact that agricultural change on populations of wild fungi that is the real cause has also been very significant. for concern. Research on this topic is urgently Gulden et al (1992) have shown that pollution needed, but will be very difficult to design. Work leading to soil acidification inhibits the produc- on fungal succession is beginning to clarify the • Volume 11,Part 2, May 1997 establishment of early-stage fungi. However, tion continues to delay the drawing up of sched- late-stage fungi which include many of the rare ules to protect endangered species of fungi and and collected species, are less well understood. their habitats. In the Netherlands the forests established on the new polders are being intensively monitored. The collecting debate This very long term recording work to determine Increased commercial collecting has led to heat- fungal succession may eventually (in say another ed debate on the rights of local people and 50 to 400 years) give some indication of the dif- landowners and on the aesthetic consequences. ferences in establishment rates of collected and In Britain there are long established de facto other fungal species. rights to collect wild fruits, and common rights With a £1 billion per year world market for giving access to such sites as Ashdown Forest, chanterelles, Leigel (1995) estimates that their the New Forest and the Forest of Dean. The law harvest value taken over a century is likely to is silent on the extension of these common rights exceed that for timber at a given site. Such eco- into the commercial collection of fungi. In nomic potential does much to raise the profile of Europe where communally owned forests are fre- fungi with landowners. Rowe (1997) reports that quent, it is relatively easy to enforce bylaws that the extreme pressures from commercial collecting allow local people to collect and restrict commer- in Oregon are already leading the US Department cial collecting. Anecdotal evidence suggests that of Agriculture to spearhead a series of long-term these local rights have in the past been exercised research projects on fungal sustainability. Until responsibly. the results are available they are taking the pre- The position of the private landowner in cautionary approach of licensing pickers. Such England and Wales is clear. The commercial strategies need to be considered in Britain. picking of fungi on private land is an offence Relief in future may come from advances in under section 4(3) of the Theft Act 1968. Those research which improve the prospects for large purchasing these fungi are also guilty of an scale commercial growing of fungi. For example, offence. In Scotland the law requires owners to the expansion of commercial growing of Agaricus prove trespass and demonstrate the fungi were bisporus may reduce the collection for sale of being pilfered with a view to being offered for Agaricus campestris. Isolated advances have sale. The aesthetic arguments are clear; sites already been made in cultivation of Morchella stripped of their fungi rob others of enjoyment. esculenta by Ower et al (1988). Danell & Camacho (1997) have just reported research Implications for BMS conservation policy advances for the chanterelle, although these are unlikely to be translated to commercial produc- Rare and endangered species are now to be pro- tion until the mycorrhizal dependency on the tected as well as identified. Habitats also need tree is broken. protection; those which already are afforded pro- For the less fashionable species the position is tection of other wildlife need it extended to their very different. The market will not justify fungal populations. The most practical and cost research and the pointers are all negative, scien- effective way to implement the precautionary tific results scarce, and monitoring is poor. principle would be to restrict collection of fungi There must therefore be serious doubts as to the on vulnerable sites to scientific sampling. The sustainability of the current level of commercial growing body of conservation legislation needs to collecting. be drafted so that it can be applied to the fungi, The Convention on Biological Diversity and implemented to give them protection. The signed at the Rio summit has given new impetus BMS should add its voice to those calling for to wildlife conservation and the protection of stricter control of pollution. Finally, commercial species. Amongst the principles set out at Rio collecting of fungi should be supported only in Agenda 21 was the 'precautionary principle'. where it is sustainable. It suggests that in order to protect the environ- A firmer conservation policy is now needed to ment the precautionary principle should be wide- improve habitat and species protection, apply ly applied by member states and that lack of full the precautionary principle and ensure the long scientific certainty should not be used as a rea- term viability of the fungi. son for postponing cost-effective measures to prevent environmental degradation. National Acknowledgements and European legislation is gradually being We are very grateful for the encouragement and strengthened as a result. It is still strongest in constructive comments of Maurice Rotheroe, Yin its protection of birds and mammals and weak- Fleming and other members of the BMS est in the protection of fungi. Lack of informa- Conservation Special Interest Committee. • Volume 11, Part 2, May 1997 References Norvell, L. (1996) Loving the ChanterelJe to death? The Alexander, K et al (1996) The management of overma- ten-year Oregon Chanterelle project.