“NON-WOOD FOREST PRODUCTS Part 17: Wild edible fungi a global overview of their use and importance to people” Yazar: Eric Boa, FAO (Birleşmiş Milletler Dünya Gıda Örgütü) Yayınları
HARVESTING METHODS AND APPROACHES
Harvesting The impact of harvesting wild edible fungi is frequently raised and a recent review provides a helpful summary of key issues that are explored in further detail below (Pilz and Molina, 2002). Collecting wild edible fungi is often compared with picking fruit from a tree. Removing all the fruit does not affect future harvests unless the tree is damaged, but might have an impact on regeneration. This appears to be true for wild edible fungi but with some reservations: removing unopened fruiting bodies prevents dispersal of spores. (TR: Doğadan yabani yenilebilir mantarların toplanması sıklıkla ağaçtan meyve toplamayla karşılaştırılır. Mantarların tamamının toplanması ana gövdeye zarar vermez fakat mantarların tamamı sporları olgunlaşmadan toplanıldığında gelecek nesli etkileyebilir. Bu da olgunlaşmamış mantarların tamamı toplandığında spor yayılmasının önlenmesi çekincesini ortaya koymaktadır) (Alternatif: Doğadan yabani yenilebilir mantarların toplanması sıklıkla ağaçtan meyve toplamayla karşılaştırılır. Meyvelerin tümünün toplanması gelecekteki hasatları etkilemez (hasat sırasında ana gövdeye zarar verilmediği müddetçe) ancak bitkinin çoğalması üzerinde etkisi olabilir. Bu durum yabani yenilebilir mantarlar için de geçerli olabilir, ancak burada bazı çekinceler mevcuttur: olgunlaşmamış mantarların toplanması sporların yayılmasını önler)
In some areas of Italy regulations prevent the collection of first flush of some edible species TR: İtalya’da bazı bölgelerde yasalar bazı yenebilir mantarların (türüf ve çörek mantarı gibi) ilk çıkışlarında toplanmasını önlemektedir (Zambonelli, 2002, personal communication: Truffles, and collecting porcini in Italy). (This makes practical sense too, since the early fruiting bodies are often damaged by insects. TR: Çünkü erken çıkan mantar gövdeleri sıklıkla böcekler tarafından hasar verildiği için bu mantıklıdır) Some collectors spread parts of the mushroom cap to encourage dispersal of spores. A study in Switzerland showed that harvesting all the fruiting bodies of 15 species of macrofungi over a ten-year period had no significant effect on production (Egli, Ayer and Chatelain, 1990) TR: İsviçre’de 10 yıl boyunca 15 farklı yenilebilir mantar üzerinde yapılan araştırmada tüm meyve organlarının toplanmasının mantar verimi üzerinde etkisinin olmadığı belirlenmiştir . If soils are compacted or leaf litter layers are disturbed, this can affect production. Indiscriminate digging for truffles, for example, is harmful. Crude raking to reveal young and immature matsutake damages the mycelium present in the upper layers of the soil. (The young fruiting bodies can be sold for a higher price.) This can be avoided by first identifying potential areas of matsutake, then using your hand to locate the tell-tale bumps while generally looking for signs of emerging fruit bodies (Arora, 1999). Most species of edible fungi are picked without causing any damage since their fruiting bodies and edible parts are all above ground. The search for truffles (Tuber spp.) is often undertaken by trained dogs (Plate 4) (Hall et al., 1998a). The traditional use of pigs is now banned in Italy because they are difficult to control and sometimes eat the truffles. Truffle dogs are not used in China and random digging used to locate fruiting bodies will affect future production. The Swiss study also showed the effect of trampling on the production of one chanterelle species. However, “normal” yields were restored once the trampling stopped (Egli, Ayer and Chatelain, 1990). Trampling is not thought to be a common source of damage. The number of collectors per unit area of forest is usually low and there is no evidence that trampling has affected yields in Malawi, for example. Commercial harvesting does increase the pressure on sites though wild edible fungi usually occur over a wide area and collectors keep apart in their searches. Enhancing productivity The decline in matsutake production in Japan in the 1980s prompted research on how to maximize yields in situ. Some success was achieved, although the increases in production failed to stem the overall decline. In the Republic of Korea methods included watering and vegetation control (Koo and Bilek, 1998). In Finland, soil surface treatments were examined for enhancement of the production of Gyromitra esculenta (Jalkanen and Jalkanen, 1978). These approaches are potentially costly and it is not known how successful they have been in increasing financial returns. An alternative is to manage forests in a way that increases production of wild edible fungi. Attempts have been made in the Pacific northwest of North America to balance the production of wood and wild edible fungi (Weigand, 1998). The conclusions of a study of management of native stands of conifers in the United States and the production of wild edible fungi, including Tricholoma matsutake and chanterelles, are summarized below (Pilz and Molina, 2002): • Clear-cut harvesting disrupts the production of most edible ectomycorrhizal fungi for ten or more years. It only recovers once the fungi have re-established on trees that are old enough to provide necessary nutrients. • A thinned stand (one where trees are selectively removed to encourage growth of remaining trees and to remove weak specimens) introduces more rain and sunshine and more rapid wetting and drying of the forest floor. Heavy thinning at one site of Douglas fir reduced chanterelle fruiting by 90 percent in the following year. Less frequent thinning might help to maintain fungal productivity but the loss of wood production might outweigh the benefits. • Compaction of soil from logging operations reduces productivity while the removal of large branches makes it easier and safer to find wild fungi without necessarily increasing base productivity. The critical issue in enhancing production of wild edible fungi is their economic importance compared to the value of wood production and other forest uses. This is often poorly understood because accurate data are missing on the value of harvests.