Zbornik gozdarstva in lesarstva 75, s. 71 - 85 GDK: 114.7-- 01:22:174.7 ‘’Abies alba Mill.’’:(497.12*02 Pokljuka)(045) Prispelo / Recieved: 3. 1. 2005 Izvirni znanstveni članek Sprejeto / Accepted: 20. 1. 2005 Original scientific paper BIODIVERSITY OF TYPES OF ECTOMYCORRHIZAE IN A NORWAY SPRUCE STAND ON POKLJUKA Urša Vilhar1, Igor Smolej2, Tadeja Trošt3, Lado Kutnar4, Hojka Kraigher5 Abstract Types of ectomycorrhizae were studied in soil cores from a young regeneration center in an autochthonous Norway spruce stand on Pokljuka (Triglav National Park, 1200 m.a.s.l.). Soil cores of equal volume (274 ml, 0 - 18 cm deep) were taken from 33 sampling plots. In the samples all the roots were counted and types of ectomycorrhizae briefly characterized. From these data diversity indices (species diversity (d) and Shannon-Weaver index of diversity (H)) were calculated. Interactions among mycorrhizae, light regime and survival of spruce seedlings were studied. Out of about 50,000 root tips approximately 1 % were non-mycorrhizal, 63 % were old unviable mycorrhizae and 36 % were identifiable ectomycorrhizal root tips, forming 27 different types of ectomycorrhizae. Sixteen types of ectomycorrhizae were briefly characterized. The Shannon diversity index for types of ectomycorrhizae was high (3.13) with respect to the above-ground diversity of vegetation (1.7). The direct site factor was shown to be negatively correlated to ~Piceirhiza cornuta. The diffuse site factor was negatively correlated to Cortinarius sp. (obtusus type) and positively correlated to Inocybe sp. The ground vegetation cover was positively correlated to Piceirhiza gelatinosa and the total vegetation cover to Elaphomyces sp. Key words: types of ectomycorrhizae, Norway spruce, natural regeneration, Pokljuka PESTROST TIPOV EKTOMIKORIZE V SMREKOVEM SESTOJU NA POKLJUKI Izvleček V majhni vrzeli domnevno avtohtonega smrekovega sestoja na Pokljuki (Triglavski narodni park) smo proučevali tipe ektomikorize na smreki. Vzorce tal smo jemali na 33. zvezdasto razporejenih vzorčnih ploskvicah s sondo prostornine 274 ml iz globine 0-18 cm. Iz vsakega vzorca smo izločili vse koreninice smreke, jih prešteli, ter na kratko opisali prisotni tip ektomikorize. Izračunali smo Indeks bogastva vrst (d) in Shannonov indeks pestrosti (H). Zanimal nas je vpliv ekoloških dejavnikov (svetlobnih razmer, naravnega pomlajevanja, zastiranja vegetacije) na porazdelitev tipov ektomikorize. Od skupno 50.000 korenin smreke je bilo približno 1 % nemikoriznih, 63 % je bilo nedoločljivih, pretežno starih tipov ektomikorize ter 36 % določljivih ektomikoriznih korenin, ki so skupaj tvorile 27 tipov ektomikorize. Predstavljenih je 16 kratkih opisov za do sedaj neopisane tipe ektomikorize. Shannonov indeks pestrosti za tipe ektomikorize (3,13) je visok glede na pestrost vegetacije (1,7). Ugotovili smo negativno korelacijo direktnega sončnega sevanja s tipom ~Piceirhiza cornuta. Difuzno sončno sevanje je v negativni odvisnosti s tipom Cortinarius sp. (obtusus tip) in v pozitivni odvisnosti s tipom Inocybe sp.. Zastiranje pritalne vegetacije je v pozitivni odvisnosti s tipom Piceirhiza gelatinosa, skupno zastiranje vegetacije pa je v pozitivni odvisnosti s tipom Elaphomyces sp. Ključne besede: tipi ektomikorize, navadna smreka, naravno pomlajevanje, Pokljuka 1 univ. dipl. inž. gozd., Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, SLO, ursa.vilhar@gozdis.si 2 mag., univ. dipl. inž. gozd., Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, SLO 3 mag.,univ. dipl. biol., BF, Department of Biology, Večna pot 111, 1000 Ljubljana, SLO 4 dr., univ. dipl. inž. gozd., Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, SLO 5 doc.dr., univ. dipl. inž. gozd., Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, SLO, hojka.kraigher@gozdis.si 72 Zbornik gozdarstva in lesarstva, 75 CONTENTS VSEBINA 1 INTRODUCTION ....................................................................... 73 UVOD 2 MATERIAL AND METHODS .................................................... 73 MATERIAL IN METODE 3 RESULTS AND DISCUSSION ................................................... 75 REZULTATI IN DISKUSIJA 4 CONCISE DESCRIPTIONS OF AS YET UNDESCRIBED TYPES ........................................................... 79 OPIS DO SEDAJ NEOPISANIH TIPOV 5 CONCLUSIONS .......................................................................... 82 ZAKLJUČKI 6 POVZETEK ................................................................................. 82 7 REFERENCES ............................................................................ 83 VIRI ACKNOWLEDGEMENTS ........................................................ 85 ZAHVALA 73 Vilhar, U., et al.: Biodiversity of types of ectomycorrhizae... 1 INTRODUCTION UVOD Below ground mycelia of mycorrhizal fungi represent a linking web for allocation of resources between plant species (READ 1998). Survival of shaded ectomycorrhizal trees has been shown to depend on the mycelial networks, connecting different sources of nutrients in a forest ecosystem (SIMARD 1996; LINDAHL et al. 1998), whereby different types of ectomycorrhizae have a different role in nutrient acquisition and translocation. Forest management practices that create intense disturbance and loss of organic matter or promote the introduction of non-ectomycorrhizal host species (ROBIČ et al. 1988) can decrease the ability of plants to form linkages with ectomycorrhizal fungi (AMARANTHUS / PERRY 1994). Mycelium extending from the adjacent stands may aid rapid regeneration of small forest openings preserving spatial and temporal continuity provided by ectomycorrhizal fungal linkages among plants. These linkages may be especially critical in cold climates where seedlings require rapid, early ectomycorrhizal formation to take advantage of the short growing season and obtain the nutrients and water to survive the long cold winter and early frosts. The success of natural regeneration of Norway spruce is classically related to light dependent temperature regime of the site (DIACI et al. 2000a). In our study we have tried to correlate interactions among mycorrhizae, soil properties, light regime and survival of spruce seedlings. In order to achieve this, types of ectomycorrhizae needed to be characterized and their abundance cross-linked to other data. The presented study is limited to study interactions among mycorrhizae, light regime and survival of spruce seedlings. Therefore, types of ectomycorrhizae Norway spruce stand on Pokljuka were characterized. 2 MATERIAL AND METHODS MATERIALI IN METODE Types of ectomycorrhizae were studied in soil cores from 33 sampling plots from a young regeneration center (size of the gap was 0.03 ha) in the permanent forest research plot (VILHAR 2001) on the Pokljuka plateau (Triglav National Park, 1200 m.a.s.l., NW Slovenia), established in an autochtonous Norway spruce stand (Figure 1). The site belongs to the association Rhytidiadelpho lorei-Piceetum (WRABER 1953 n. nud.) ZUPANČIČ 74 Zbornik gozdarstva in lesarstva, 75 (1976) 1981 em. 1999), while the soils show a heterogeneous distric cambisol to podsol mixture (URBANČIČ / KUTNAR 1988). The design of sampling plots (size 0.5 x 0.5 m) followed the main compass directions (one each 2 m). Figure 1: Research plot with star-like arrangement of sampling plots (DIACI et al. 2000a; DIACI et al. 2000b; reprinted with permission of the publisher) Slika 1: Skica ploskve z zvezdasto razporejenimi ploskvicami (DIACI et al. 2000a; DIACI et al. 2000b; ponatisnjeno z dovoljenjem založnika) Analyses of mycorrhizae were done in soil cores of 274 ml, 0 - 18 cm deep, 1 per square plot. The sampling was done in August 1997 (17 samples), October 1999 (12 samples) and in June 2000 (5 samples). The samples were kept in plastic bags in the refrigerator at 4 – 8 °C till further processing. Samples were carefully washed, all the roots (of 1 mm length or more) were counted and types of ectomycorrhizae briefly characterized (AGERER 1987-2002; GRONBACH 1988; BERG 1989; KRAIGHER 1996). Non-turgescent types were placed into a single category of old unidentifiable types. Selected types were concisely described by (TROŠT et al. 1999). Brief descriptions of the types of ectomycorrhizae which have not been previously characterized are presented in our results. Diversity indices (species diversity (d) and Shannon-Weaver index of diversity (H)) were calculated after (ATLAS / BARTHA 1981). 75 Vilhar, U., et al.: Biodiversity of types of ectomycorrhizae... Diffuse and direct site light factors (potential direct irradiation in hours from April to August) according to (ANDERSON 1964) were assessed with horizontoscope as described in (DIACI et al. 2000b). The original method was modified and updated by applying photography and computerized image analysis. At all plots, cover estimates of ground vegetation were made for all plant species in five vertical layers: moss, lower and upper herb layers, lower and upper shrub layers (KUTNAR 2000). In all plots the number of one-year-old seedlings, number of seedlings up to 10 cm and number of saplings higher than 10 cm was counted or estimated as described (DIACI et al. 2000b). The correlation between selected types of ectomycorrhizae (occurring in most plots) and variables, describing radiation and natural spruce regeneration was analyzed using Spearman’s rank correlation coefficient (STATISTICA for Windows 1984-1995). 3 RESULTS AND DISCUSSION REZULTATI IN DISKUSIJA In total 51,049 root tips were counted, 1 % of which were non-mycorrhizal, 63 % were old unviable mycorrhizae and 36 % were identifiable ectomycorrhizal root tips, forming 27 Nonmycorrhizal roots / Nemikorizne korenine Old unidentifiable types / Stari neidentificirani tipi 63 % Mycorrhizal roots / Mikorizne korenine 36 % 76 Zbornik gozdarstva in lesarstva, 75 Three types could be identified by anatomical characteristics to the species level and 9 to the group or genus level. Further 3 types showed characteristics similar but not identical to the already described types (in figures marked with ~). Five types of ectomycorrhizae were preliminarily described by (TROŠT et al. 1999). Table 1: Types of ectomycorrhizae Preglednica 1: Tipi ektomikorize Types of ectomycorrhizae / N Tipi ektomikorize o. of root tips Št. korenin / Reference / % Vir opisa Cenococcum geophilum 1618 8.8 AGERER (1987-1999) Hydnellum peckii 42 0.2 AGERER (1987-1999) Hygrophorus olivaceoalbus 45 0.2 AGERER (1987-1999) ~Piceirhiza cornuta 302 1.6 (TROŠT et al 1999) ~Pinirhiza epidermoides 674 3.7 (TROŠT et al 1999) ~Pinirhiza stellanulata 24 0.1 (TROŠT et al 1999) Cortinarius (obtusus type) 233 1,.3 See description / Glej opis Elaphomyces sp. 3148 17.2 See description / Glej opis Inocybe sp. 482 2.6 See description / Glej opis Lactarius sp., Q-type 645 3.5 See description / Glej opis Lactarius sp., P-type 1002 5.5 See description / Glej opis Thelephora sp. 378 2.1 See description / Glej opis Tomentella spp. 712 3.9 See description / Glej opis Tricholoma sp. 47 0.3 See description / Glej opis Tylospora spp. 7230 39.4 See description / Glej opis Type SLO-UV 1058 234 1.3 See description / Glej opis Type SLO-UV 1060 19 0.1 See description / Glej opis Type SLO-UV 1065 396 2.2 See description / Glej opis Type SLO-UV 1093 331 1.8 See description / Glej opis Type SLO-UV 1108 10 0.1 See description / Glej opis Type SLO-UV 1109 24 0.1 See description / Glej opis Type SLO-UV 1122 39 0.2 See description / Glej opis Type SLO-UV 1139 12 0.1 See description / Glej opis Type SLO-UV 1164 365 2.0 See description / Glej opis Type SLO-UV 1201 156 0.9 See description / Glej opis Type SLO-TT 714 16 0.1 (TROŠT et al 1999) Type SLO-TT 724 164 0.9 (TROŠT et al 1999) 77 Vilhar, U., et al.: Biodiversity of types of ectomycorrhizae... Table 2: Species richness (d) and Shannon-Weaver index of diversity (H) Preglednica 2: Indeks bogastva vrst (d) in Shannonov indeks pestrosti (H) No. of ectomycorrhizal types / št. tipov ektomikorize 27 No. of ectomycorrhizal roots / št. ektomikoriznih korenin 18,340 Species richness / Indeks bogastva vrst (d) 7.51 Shannon index of diversity / Shannonov indeks pestrosti (H) 3.13 The Shannon diversity index for types of ectomycorrhizae was high (3.13) with respect to the Shannon diversity index for types of ectomycorrhizae in an old forest stand (2.23), clear cut (1.48) and the above-ground diversity of vegetation on the same site (1.7) (URBANČIČ / KUTNAR 1988; KRAIGHER 1999). Spatial and temporal linkages with ectomycorrhizal mycelium between the old and the new stand resulted in extreme diversity in the mycorhyzosphere in a young regeneration center, regardless of low diversity among natural pure spruce stand (VILHAR 2001). There was no significant correlation between natural regeneration of spruce and total number of counted roots, number of old unviable ectomycorrhizal root tips or number of types per plot. The number of non-mycorrhizal root tips was positively correlated with the number of one-year-old seedlings (R = 0.36*) and seedlings up to 10 cm (R = 0.39*). Since the non-mycorrhizal roots were mostly translocating roots of dimensions over 2 mm, we assume they belonged mostly to the old trees encircling the gap or to the remaining roots of the cut trees from within the gap. Table 3: Spearman’s rank correlation coefficient(R)betweenvariablesindicatingvegetation cover, direct and diffuse solar radiation and the counted root tips of ectomycorrhizal types. Only statistically significant trends are presented (p<0.05). Preglednica 3: Spearmanov koeficient korelacije (R) med spremenljivkami, ki nakazujejo svetlobne razmere in zastiranje vegetacije ter številčnostjo tipov ektomikorize. Predstavljeni so statistično zančilni trendi (p<0.05) Type of ectomycorrhizae / Tip ektomikorize Variable / Spremenljivka N Spearman's R t(N-2) p-level Direct site factor ~Piceirhiza cornuta 33 -0.392 -2.376 0.024 Diffuse site factor Inocybe sp. 33 0.503 3.238 0.003 Cortinarius sp, (obtusus type) 33 -0.357 -2.129 0.041 Ground vegetation cover (without spruce seedlings) Hygrophorus olivaceoalbus 33 0.400 2.433 0.021 Total vegetation cover Elaphomyces sp. 33 0.392 2.374 0.024 78 Zbornik gozdarstva in lesarstva, 75 For only a limited number of ectomycorrhizal types correlation to radiation factors are statistically significant. Direct site light factor is negatively correlated to ~Piceirhiza cornuta. Diffuse site light factor is negatively correlated to Cortinarius sp. (obtusus type) and positively correlated to Inocybe sp. Ground vegetation cover (without spruce seedlings) was positively correlated to Piceirhiza gelatinosa and total vegetation cover to Elaphomyces sp.. The results of the irradiation studies at the plot show that Norway spruce can successfully germinate and survive the first years if the direct site factor is not abundant and the roots of the seedlings come in touch with the root system of the old trees (DIACI et al. 2000b). When the critical period for seedling establishment is over, the importance of other site factors increase (more podsolised soil, higher content of organic matter and sparse forest vegetation coverage (ibid). Since direct correlations between ectomycorrhizal types and spruce seedlings were not significant, we assume that a complex interaction of ecological factors, e.g. micro relief, soil properties, radiation, vegetation, host species (KRAIGHER 2000), coarse woody debris (ALLEN 1991) and human impact (pasture, recreation,…) (PILTAVER 2000) influence the spatial distribution of ectomycorrhizae. 79 Vilhar, U., et al.: Biodiversity of types of ectomycorrhizae... 4 CONCISE DESCRIPTIONS OF AS YET UNDESCRIBED TYPES OPIS DO SEDAJ NEOPISANIH TIPOV Table 4: Concise descriptions of as yet undescribed types and their schematic presentations Preglednica 4: Opis do sedaj neopisanih tipov ter njihova shematska predstavitev 80 Zbornik gozdarstva in lesarstva, 75 Table 4: Concise descriptions of as yet undescribed types and their schematic presentations (continuation) Preglednica 4: Opis do sedaj neopisanih tipov ter njihova shematska predstavitev 81 Vilhar, U., et al.: Biodiversity of types of ectomycorrhizae... Table 4: Concise descriptions of as yet undescribed types and their schematic presentations (continuation) Preglednica 4: Opis do sedaj neopisanih tipov ter njihova shematska predstavitev 82 Zbornik gozdarstva in lesarstva, 75 5 CONCLUSIONS ZAKLJUČKI The diversity indices of ectomycorrhizae in soil cores from our site in a young growth forest were higher than in an old forest stand and nearly two times higher than the diversity index, calculated for the vegetation cover from the same site. Low diversity of vegetation in a natural pure spruce stand has no effect on the extreme diversity of mycorhyzosphere. The number of non-mycorrhizal root tips was positively correlated with the number of one-year-old seedlings and seedlings up to 10 cm, but there was no significant correlation between natural regeneration of spruce and total number of counted roots, number of old unviable ectomycorrhizal root tips or number of types per plot. For some of the ectomycorrhizal types correlation to radiation factors and vegetation cover was proven. ~Piceirhiza cornuta is negatively correlated to the direct site factor. Cortinarius sp. (obtusus type) is negatively correlated and Inocybe sp. positively correlated to the diffuse site factor. Piceirhiza gelatinosa was positively correlated to the ground vegetation cover (without spruce seedlings) and Elaphomyces sp. to the total vegetation cover. 6 POVZETEK Micelij ektomikoriznih gliv predstavlja osnovno povezovalno komponento med drevjem, dekompozitorji v gozdnih tleh in pritalno vegetacijo v gozdnih ekosistemih. Obravnavali smo tipe ektomikorize na smreki, ki se pojavljajo v majhni vrzeli odraslega, domnevno avtohtonega smrekovega sestoja na Pokljuki (Triglavski narodni park). Vzorce tal smo jemali na zvezdasto razporejenih vzorčnih ploskvicah s sondo prostornine 274 ml iz globine 0-18 cm, izločili vse koreninice smreke, jih prešteli ter razvrstili glede na prisotnost ektomikorize. Tipe ektomikorize smo identificirali oziroma, če to ni bilo možno, na kratko opisali. Izračunali smo Indeks bogastva vrst (d) in Shannonov indeks pestrosti (H). Zanimal nas je vpliv ekoloških dejavnikov (svetlobnih razmer, naravnega pomlajevanja, zastiranja vegetacije) na porazdelitev tipov ektomikorize. Od skupno 50.000 korenin smreke je bilo približno 1 % nemikoriznih, 63 % je bilo nedoločljivih, pretežno starih tipov ektomikorize, ter 36 % določljivih ektomikoriznih korenin, ki so skupaj tvorile 27 tipov ektomikorize. Trem tipom smo na podlagi anatomskih 83 Vilhar, U., et al.: Biodiversity of types of ectomycorrhizae... značilnosti določili vrsto, 9 smo jih uvrstili v rod ali skupino. Trije tipi so imeli podobne značilnosti, kot že opisani tipi, a ne povsem identičnih. Te smo označili z znakom (~). Predstavljenih je 16 kratkih opisov za do sedaj neopisane tipe ektomikorize. Shannonov indeks pestrosti za tipe ektomikorize je 3,13. Če primerjamo ugotovljeni indeks za populacijo mikoriznih gliv s Shannonovim indeksom pestrosti, ugotovljenim za pritalno vegetacijo, ki znaša 1,71, sklepamo, da relativno majhna pestrost rastlinstva še ne pomeni majhne raznovrstnosti med glivami, niti v celotni biocenozi. Z našim popisom ugotovljeni Shannonov indeks pestrosti izraža veliko vrstno pestrost mikoriznih gliv oziroma biokomponente v gozdnih tleh na majhni površini. Predvidevamo, da na pomlajevanje v manjših vrzelih vpliva časovna in prostorska povezanost starega in novonastajajočega sestoja z micelijem ektomikoriznih gliv. Ta povezava je odločilnega pomena predvsem v ekstremnejših rastiščnih pogojih, saj hitra kolonizacija ektomikoriznih gliv prispeva k izboljšanju preživetja mladja v stresnih pogojih okolja. Pri proučevanju prostorske porazdelitve tipov ektomikorize v povezavi z ekološkimi dejavniki (svetlobne razmere, zastiranje vegetacije) smo ugotovili le nekaj statistično značilnih povezav. Direktno sončno sevanje je v negativni odvisnosti s tipom ~Piceirhiza cornuta. Difuzno sončno sevanje je v negativni odvisnosti s tipom Cortinarius sp. (obtusus tip) in v pozitivni odvisnosti s tipom Inocybe sp. Zastiranje pritalne vegetacije (brez pomladka smreke) je v pozitivni odvisnosti s tipom Piceirhiza gelatinosa, skupno zastiranje vegetacije pa je v pozitivni odvisnosti s tipom Elaphomyces sp. Neposrednih povezav med tipi ektomikorize ter številom smrekovega pomladka nismo ugotovili, zato sklepamo, da na prostorsko porazdelitev tipov ektomikorize vpliva kompleks ekoloških dejavnikov (mikrorelief, talne razmere, svetlobne razmere, vegetacija, mrtva lesna biomasa, vplivi človeka,…). 7 REFERENCES VIRI AGERER, R. 1987-2002. Colour Atlas of Ectomychorrhizae, 1st - 11th delivery. 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We would like to thank Tone Kralj for development of software for computerized image analysis, Matej Rupel for counting and field work and prof. dr. Jurij Diaci for providing the equipment for irradiation measurements and valuable suggestions and comments. Urša Vilhar received the Prešeren Award for her Diploma Thesis on the study of types of ectomycorrhizae.