Ectomycorrhizal fungi in dry and wet dipterocarp forests in northern Thailand - diversity and use as food 1Dell B, 1,2Sanmee R, 2Lumyong P and 2Lumyong S 1School of Biological Sciences and Biotechnology, Murdoch University, Perth, Australia 2Department of Biology, Chiang Mai University, Chiang Mai, Thailand Abstract Wild mushrooms are annually harvested for food from dry and wet dipterocarp forests of northern Thailand. Most of the species gathered fruit in association with host trees and form symbiotic associations know as ectomycorrhizas. This paper documents the diversity of ectomycorrhizal (ECM) fungi and collection as food. Forest fungi were collected from dipterocarp-dominated (mostly Dipterocarpus and Shorea spp.) primary and secondary forests in four provinces of northern Thailand, Chiang Mai, Chiang Rai, Mae Hong Son and Phayao Provinces, over three years. For comparative purposes, the diversity of larger fungi was also investigated in forests dominated by the Fagaceae or the Pinaceae. The dry dipterocarp forests had greater diversity of fruiting ECM fungi than the wet dipterocarp forests (11 families, 21 genera and 52 spp.; 8 families, 15 genera and 24 spp., respectively). The dominant genera in the dry dipterocarp forests were Russula (11 spp.), Boletus (7 spp.) and Amanita (5 spp.) whereas in the wet dipterocarp forests, Amanita (5 spp.) was the main genus followed by Lactarius = Russula (3 spp. each). Overall, ectomycorrhizal fungal diversity in dipterocarp forests (57 spp.) was intermediate between oak (161 spp.) and pine (15 spp.) forests. However, 65% of the ECM fungi that were associated with dipterocarps were not observed fruiting in other forest types. In the wet season, 19 ECM fungal species in ten genera were taken from dipterocarp forests (19 spp. from dry forests, 8 spp. from wet forests) by local people for sale in village, roadside and town markets. The market value of the most valuable fungus, the earth star (hed phor) Astraeus hygrometricus, ranged from 300-400 Baht (7-10 US$)/kg. Aspects of fungal conservation and their use in reforestation are discussed. Introduction The uplands of Northern Thailand support a diverse mosaic of forest types determined principally by elevation, moisture and disturbance (Gardner et al. 2000). More than fourteen genera of forest trees have symbiotic associations with higher fungi in the region. Deciduous dipterocarps (dry dipterocarp forests) occur at low elevation (350 - 400 m), on shallow soils (Khamyong et al. 1996), whereas the semi-evergreen dipterocarps (wet dipterocarp forests) occur on moist soils at mid-elevation (800 - 1200 m). The Fagaceae (Castanopsis, Lithocarpus and Quercus) are a dominant component of hill evergreen forests. Pinus kesiya and P. merkusii are locally prominent on dry sites at mid-elevation. A common feature of these forests is their dependence on ECM fungi for their growth and survival. 1 The Dipterocarpaceae are well-known as an ECM family of trees in SE Asia (e.g. Smits 1994, Lee et al. 1997). In spite of the likely importance of ECM fungi for the health of dipterocarp forests in northern Thailand, the subject has received little attention. There is no comprehensive higher fungal flora of Thailand though there are useful popular accounts of the more common species (Rachabunditayasathan 1996, Chansrikul 1998). Information on selected groups of fungi in northern Thai forests are available in Boonthavikoon (1998) and in unpublished theses including Konsab (1998), Phongmanee (1999), Phuthima (1999) and Tongglam (1999). Unlike for southwest China where the human use of forest fungi has been well documented, there is little information available on the extent and scope of mushroom collecting in northern Thailand (Dell et al. 2000). Furthermore, ethnobotanical studies in the region (e.g. Anderson 1993) have neglected the importance of forest fungi. The purpose of this paper is to begin the process of documentation of forest fungi in northern Thailand and their cultural value. Materials and methods Sporocarps of wild macro-fungi were systematically sampled from forests in Chiang Mai, Chiang Rai, Mae Hong Son and Phayao Provinces in northern Thailand, during the wet seasons (June-September) of 2001-2003. The fungi were collected under ectomycorrhizal dipterocarps (Dipterocarpus alatus, D. costatus, D. obtusifolius, D. tuberculatus, D. turbinatus, Hopea odorata, Shorea obtusa, S. siamensis), oaks (Castanopsis acuminatissima, C. argyrophylla, C. armata, C. diversifolia, C. echinocarpa, C. ferox, C. indica, C. tribuloides, Lithocarpus polystachyus, L. tenuinervis, Quercus kerrii, Q. kingiana, Q. mespilifoliodes, Q. vestita), and pines (Pinus kesiya, P. merkusii). Specimens were photographed, their morphological and anatomical features described in detail (Sanmee 2004) and they were then lodged in the Fungal Herbarium of Chiang Mai University. Edible ECM fungi were observed in the Chiang Mai city market (Suthep), in road-side stalls of Weing Par Pao District in Chiang Rai Province, and in the local market (Mae Tam Market) in Phayao Province during the wet season in 1996 and 2000. Field collections were made at the following sites: A. Dry dipterocarp forests A1. Mae Wang Conservation Forest, Sanpanthong District, Chiang Mai Province. Elevation 350 - 400 m asl. A2. Huay Hong Krai, Doi Saked District, Chiang Mai Province. Elevation ca. 400 m asl. A3. Doi San Phai, Ban Mae Sard, Chiang Rai Province. Elevation ca. 700 m asl. A4. Doi Pu Ya, Mae Hon Song Province. Elevation 350 - 400 m asl. A5. Doi Kum Phra, Mae Hon Song Province. Elevation 350 - 400 m asl. B. Wet dipterocarp forests B1. Near Phra-Tard-Doi-Suthep Temple, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation ca. 900 m asl. B2. Lum Namn Chiang Dao Research Centre, Chiang Mai Province. Elevation 500-600 m asl. B3. Khun Chae National Park, ZZ Province. Elevation 900 - 1,000 m asl. 2 B4. Ban Huay Teecha, Soap Mei District, ZZ Province. Elevation ca. 800 m asl. B5. Doi Luang National Park, ZZ Province. Elevation 700 - 800 m asl. C. Oak forests C1. Huay Kog Ma, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,000 - 1,300 m asl. C2. Sun Gu, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,400 - 1,500 m asl. C3. Khun Chang Kian, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,200 - 1,300 m asl. C4. Phar Dum, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation ca. 1,400 m asl. A2, B1 and B3. D. Pine forests D1. Yord Doi Pui, Doi Suthep-Pui National Park, Chiang Mai Province. Elevation 1,600 - 1,685 m asl. D2. Baw Gaow experimental station, Mae Hon Song Province. Elevation 700 - 800 m asl. B1, B3 and B5. Results The diversity of ECM fungi fruiting in secondary and primary forests in northern Thailand was low under pines, intermediate under dipterocarps and high under oaks (Table 1). There were three times as many ECM fungal species fruiting under oaks than under dipterocarps. A total of 57 species of putative ECM fungi were collected under dipterocarps of which 65 % were not collected in other vegetation types suggesting preferential association of these species with dipterocarp hosts. The most abundant basidiomes were species of Amanita, Astraeus, Heimiella, Pterygellus, Mycoamaranthus and Russula. Three genera (Russula, Boletus and Amanita) dominated under dipterocarps contributing 42% of the diversity of ECM fungi compared to two genera under pines (Lactarius and Amanita with 60% of diversity) and four genera under oaks (Russula, Lactarius, Amanita and Boletus with 56.5% of diversity). The dry dipterocarp forests had greater diversity of fruiting ectomycorrhizal fungi (Table 2) than the wet dipterocarp forests (11 families, 21 genera and 52 spp.; 8 families, 15 genera and 24 spp., respectively). The percentage of fungal species restricted to dry or wet dipterocarp forests was ca. 63 or 21%, respectively. Overall, 19 species were collected in both wet and dry forest types. The dominant genera in the dry dipterocarp forests were Russula (11 spp.), Boletus (7 spp.) and Amanita (5 spp.) whereas in the wet dipterocarp forests, Amanita (5 spp.) was the main genus followed by Lactarius = Russula (3 spp. each). Edible forest fungi are routinely collected for food in Northern Thailand and sold in local markets. In the wet season, 19 ECM fungal species in ten genera were removed from dipterocarp forests (19 spp. from dry forests, 8 spp. from wet forests) by local people for sale in village, roadside and town markets. The fungi are mostly sold to local consumers in small quantities. However, the earth star (hed phor) Astraeus 3 hygrometricus is collected in large quantities and much is preserved in cans for domestic consumption as well as export. Currently, this is the most valuable fungus, and prices of fresh sporocarps ranged from 300-400 Baht (7-10 US$)/kg. Discussion In terms of the presence of above-ground sporocarps of ECM fungi, the dry dipterocarp forests of northern Thailand have a much higher diversity than the wet dipterocarp forests. Furthermore, more than half of the ECM fungal species associated with dipterocarps did not fruit in the collection years in nearby forests dominated by ECM trees in the Fagaceae or Pinaceae. The ECM fungal flora of Thailand is still relatively poorly researched and new species of common ECM fungi continue to be described as groups are examined in more detail (e.g. Lumyong et al. 2003, Sanmee et al. 2003b, Kanchanaprayudh et al. 2004, Phosri et al. 2004). However, the number of putative ECM fungal species collected in this study compares favourably with results from other projects in the region. For example, Chalermpongse (1987) surveyed a dry-deciduous dipterocarp forest and a semi-evergreen dipterocarp forest in Amphur Pak Thong Chai and reported 35 species of ECM fungi fruiting over three years in the wet season. The deciduous forest had twice as many ECM species (29) as the evergreen forest. Smits (1994) collected over 80 species of putative ECM fungi in wet dipterocarp forests in East-Kalimantan.