Canadian Journal of Forest Research Fungi decaying the wood of fallen beech (Nothofagus) trees in the South Island of New Zealand. Journal: Canadian Journal of Forest Research Manuscript ID cjfr-2018-0179.R1 Manuscript Type: Article Date Submitted by the 29-Aug-2018 Author: Complete List of Authors: Hood, Ian; Scion (New Zealand Forest Research Institute) McDougal, Rebecca; Scion Somchit, Chanatda; Scion Kimberley, Mark; Scion (New Zealand Forest Research Institute) Lewis, Aymee;Draft Scion Hood, Joy; 25 Simmonds Crescent fungal biodiversity, decomposer fungi, decay of fallen Nothofagus stems, Keyword: New Zealand indigenous forest ecology, basisiomycete wood colonisers Is the invited manuscript for consideration in a Special Not applicable (regular submission) Issue? : https://mc06.manuscriptcentral.com/cjfr-pubs Page 1 of 46 Canadian Journal of Forest Research 1 Fungi decaying the wood of fallen beech (Nothofagus) trees in the South Island of New Zealand. 2 3 Ian A. Hood, Rebecca L. McDougal, Chanatda Somchit, Mark O. Kimberley, Aymee S.R. Lewis and Joy 4 O.L. Hood 5 I.A. Hood, R.L. McDougal, C. Somchit, M.O. Kimberley, and A. Lewis. New Zealand Forest Research Institute (Scion), 6 Private Bag 3020, Rotorua 3046, New Zealand. 7 J.O.L. Hood. 25 Simmonds Crescent, Rotorua 3015, New Zealand. 8 Abstract 9 10 In order to extend present knowledge of communities of wood decay fungi in native forests, basidiomycetes 11 and ascomycetes were isolated from within 15 fallen stems in beech (Nothofagus, Nothofagaceae) forests in 12 the South Island of New Zealand. Fungal species were identified as precisely as possible using traditional 13 culturing and molecular approaches. The internal distribution of species within stems was determined. 14 Common fungi that occupied significant portionsDraft of stems were Ganoderma applanatum sensu Wakefield, 15 Australoporus tasmanicus, Inonotus nothofagi, Pleurotus purpureo-olivaceus and an unidentified 16 hymenochaetaceous species. Richness and diversity of basidiomycete species were greater in stems of red 17 beech (Nothofagus fusca) and silver beech (N. menziesii) than in those of matai (Prumnopitys taxifolia, 18 Podocarpaceae) and tawa (Beilschmiedia tawa, Lauraceae), as determined from earlier studies in podocarp 19 hardwood and beech indigenous forests. There was greater similarity in the species composition of 20 basidiomycete fungi colonising the three beech species compared with those colonising rimu (Dacrydium 21 cupressinum, Podocarpaceae), tawa and matai. Based on observations in this study and on international 22 research on the effects of selective logging on basidiomycete biodiversity, the decision to restrict to 50% the 23 extraction of wood following storm damage in beech forests on the South Island West Coast appears to have 24 been appropriate. 25 Key words: fungal biodiversity, decomposer fungi, decay of fallen Nothofagus stems, New Zealand 26 indigenous forest ecology 27 1. Introduction 28 29 The decay of woody matter is crucial to the overall forest ecosystem. The release of carbon and minerals 30 during this process offsets the reverse actions of carbon assimilation and nutrient uptake by the living trees. https://mc06.manuscriptcentral.com/cjfr-pubs Canadian Journal of Forest Research Page 2 of 46 31 Both aspects must be considered for a proper appreciation of a forest’s ecology. Balancing the carbon budget 32 requires quantification not only of carbon fixation but also of its escape during decomposition (Beets et al. 33 2008; Mason et al. 2013). The bound minerals that are also freed as the wood decays are essential 34 supplements within the forest’s nutrient cycle (Clinton et al. 1999, 2009; Buchanan et al. 2001). 35 36 The organisms responsible for wood breakdown are therefore an important element within the total forest 37 biota. However, knowledge of the decomposer populations and their ecology in New Zealand’s native forests 38 is still patchy. In particular, how is the diversity of these species affected by the creation of woody debris 39 through wind throw, and conversely, by the removal of stems during sustainable logging or in salvage 40 recovery after storms? In April, 2014, widespread damage from Cyclone Ita affected native forests in the 41 West Coast Region of the South Island (Platt et al. 2014). In order to balance conflicting commercial and 42 conservation interests, the New Zealand Department of Conservation (DOC), with assistance and advice 43 from the Ministry for Primary Industries (MPI),Draft authorised log recovery in up to 50% of the affected areas on a 44 hectare by hectare basis, and up to 50% of the fallen wood within these permitted salvage zones (Watson 45 2017). The remaining fallen stems were left as habitat shelter for bird and insect species occupying and 46 feeding in decaying logs and for nutrient recycling purposes. However, the knowledge that determined these 47 criteria appears limited. Certainly, virtually nothing is known about the way wood recovery influences the 48 residual populations of wood decay fungi in New Zealand native forests. There has been work in relatively 49 undisturbed forests, but even here more studies are needed. An awareness of these fungi and the way they 50 colonise the woody debris under ostensibly normal circumstances provides a necessary benchmark for 51 making comparisons after catastrophic weather events. 52 53 Field work to investigate the biology of fungi causing wood decay in New Zealand native forests has been 54 conducted intermittently over the last three decades, not counting the species lists of Gilmour (1966) and 55 McKenzie et al. (2000), which include ecological observations. Studies in two widely separated podocarp 56 hardwood forests, one in each of the North and South Islands, indicated a degree of commonality with 57 respect to the dominant decay fungi present in fallen stems of three tree species, rimu (Dacrydium 58 cupressinum Sol. ex Lamb., Podocarpaceae), matai (Prumnopitys taxifolia (Banks & Sol. ex D. Don) de 59 Laub., Podocarpaceae) and tawa (Beilschmiedia tawa (A. Cunn.) Kirk, Lauraceae) (Hood et al. 1989, 2004; https://mc06.manuscriptcentral.com/cjfr-pubsPage 2 of 46 Page 3 of 46 Canadian Journal of Forest Research 60 Hood 2012; Hood and Gardner 2009). On the other hand, two studies in beech (Nothofagus, Nothofagaceae) 61 forests, one in each island, revealed considerable variety in composition between the major decomposer 62 species colonising different trees (Allen et al. 2000; Hood et al. 2008). This disparity may have been due to 63 differences in location (and climate), tree species, individual stems (varying in size and degree of 64 decomposition), supply of fungal inoculum, the study methodology used, or some combination of these or 65 additional factors. The study in the South Island monitored the fruitbodies appearing seasonally on fallen 66 mountain beech trees (Nothofagus solandri var. cliffortioides (Hook. f.) Poole; synonym, Fuscospora 67 cliffortioides (Hook. f.) Heenan & Smissen; Allen et al. 2000). The North Island study considered the fungi 68 isolated from within fallen stems of red beech (Nothofagus fusca (Hook. f.) Oerst.; synonym, Fuscospora 69 fusca (Hook. f.) Heenan & Smissen) and silver beech (Nothofagus menziesii (Hook. f.) Oerst.; synonym, 70 Lophozonia menziesii (Hook. f.) Heenan & Smissen); Hood et al. 2008). 71 72 In order to comprehend this variety more clearlyDraft further sampling is needed. A new study was therefore 73 undertaken in the South Island employing the same isolation technique as used in the central North Island 74 Nothofagus investigation. It was decided to sample all three Nothofagus species previously examined and to 75 choose sites at a number of locations. In contrast to earlier studies, which were mostly conducted following 76 known storm events, it was not possible in this study to determine the period since windfall. Instead, trees at 77 a similar, intermediate stage of physical decomposition were selected. 78 79 The purpose of the study, then, was to characterise the composition, incidence, diversity and internal 80 distribution of the fungi decaying fallen Nothofagus trees of different species at separate locations, in order to 81 add to the body of knowledge about these organisms in indigenous forests in New Zealand. As a secondary 82 aim, it was anticipated that, although conducted in comparatively undisturbed forests, it would provide 83 information on the effects that salvage logging in storm damaged stands might have on the prevalence of 84 these fungi. 85 86 2. Methods 87 88 2.1 Sites https://mc06.manuscriptcentral.com/cjfr-pubsPage 3 of 46 Canadian Journal of Forest Research Page 4 of 46 89 90 The study was undertaken at three South Island locations, in red and silver beech mixed forest in the Maruia 91 Valley between Springs Junction and Lewis Pass (Latitude -42.381°, Longitude 172.307°; 560m a.s.l.), in 92 mountain beech forest at Klondyke Corner near Arthur’s Pass (-43.006°, 171.582°; 640m a.s.l.), and in the 93 Eglinton Valley between Te Anau and Milford Sound. The Eglinton Valley location was subdivided into two 94 sites 11 km apart, in mountain beech forest at Boyd Creek (-45.135°, 167.950°; 320m a.s.l.) and in red and 95 silver beech forest at East Branch (-45.050°, 168.012°; 360m a.s.l.). The two most distant locations spanned 96 a length of ca. 460 km. 97 98 2.2 Sample trees 99 100 Five uprooted trees or fallen, wind-snapped stems were chosen at each location (15 trees, total; Table 1; Fig. 101 1a,b). Trees at the Maruia Valley location wereDraft of silver beech, at Klondyke Corner of mountain beech, and in 102 the Eglinton Valley of mountain beech (Boyd Creek) or red beech (East Branch). Selection was arbitrary, 103 without prior examination for any fungal fruitbodies present, except that stems were avoided that were either 104 recent falls with hard sound wood, or conversely, extensively decomposed with friable texture, collapsed form 105 and little remaining bark.