Soil spore bank communities of ectomycorrhizal fungi in endangered Chinese Douglas-fir forests

Abstract

Chinese Douglas-fir (Pseudotsuga sinensis) is an endangered Pinaceae species found in several isolated regions of China. Although soil spore banks of ectomycorrhizal (ECM) fungi can play an important role in seedling establishment after disturbance, such as in the well-known North American relative (Pseudotsuga menziesii), we have no information about soil spore bank communities in relict forests of Chinese Douglas-fir. We conducted bioassays of 73 soil samples collected from three Chinese Douglas-fir forests, using North American Douglas-fir as bait seedlings, and identified 19 species of ECM fungi. The observed spore bank communities were significantly different from those found in ECM fungi on the roots of resident trees at the same sites (p = 0.02). The levels of potassium (K), nitrogen (N), organic matter, and the pH of soil were the dominant factors shaping spore bank community structure. A new Rhizopogon species was the most dominant species in the spore banks. Specifically, at a site on Sanqing Mountain, 22 of the 57 surviving bioassay seedlings (representing 21 of the 23 soil samples) were colonized by this species. ECM fungal richness significantly affected the growth of bioassay seedlings (R = 0.20, p = 0.007). Growth was significantly improved in seedlings colonized by Rhizopogon or Meliniomyces species compared with uncolonized seedlings. Considering its specificity to Chinese Douglas-fir, predominance in the soil spore banks, and positive effect on host growth, this new Rhizopogon species could play critical roles in seedling establishment and forest regeneration of endangered Chinese Douglas-fir.

Soil propagule banks of ectomycorrhizal fungi associated with <i>Larix cajanderi</i> above the treeline in the Siberian Arctic

“…cajanderi roots at the treeline ( Miyamoto et al, 2022 ). This reduction is comparable to those reported in previous studies that performed bioassay experiments in temperate and boreal forests (12-45%) ( Glassman et al, 2015 ; Miyamoto & Nara, 2016 ; Murata et al, 2017a ; Wen et al, 2018 ).…”

“…geophilum was reduced at KTY, perhaps due to soil conditions or other environmental factors rather than distance effects because this species is a common EM associate of tundra shrubs ( Miyamoto et al, 2022 ). Although we did not detect distance effects between the two sites, the overall fungal colonization rates were lower in this tundra (28.6%) than in similar bioassay experiments conducted in mature forests (57-100%; Miyamoto & Nara, 2016 ; Murata et al, 2017a , b ; Wen et al, 2018 ). Several bioassay studies have reported reduced EM colonization from soils collected beyond host range limits at local (1-3 km) and regional (~300 km) scales ( Nuñez et al, 2009 ; Fujiyoshi et al, 2011 ; Reithmeier & Kernaghan, 2013 ; Pickles et al, 2015 ), primarily due to dispersal limitation of the fungal propagules ( Peay et al, 2012 ).…”

“…cajanderi populations growing at the Arctic treeline ( Miyamoto et al, 2022 ), implying their key role in the establishment of Larix forests at the ecotone. Suilloid fungi exhibit strong specificity to the family Pinaceae ( Molina & Trappe, 1994 ; Nguyen, Vellinga, Bruns, & Kennedy, 2016 ) and often promote growth and drought resistance in associated seedlings ( Wen et al, 2018 ; Li et al, 2021 ; Wang et al, 2021 ). They produce abundant fruiting bodies containing proliferate spores that are dispersed long distances by wind and animals ( Ashkannejhad & Horton, 2006 ; Peay, Schubert, Nguyen, & Bruns, 2012 ; Urcelay, Longo, Geml, Tecco, & Nouhra, 2017 ).…”

The significance of retention trees for survival of ectomycorrhizal fungi in clear‐cut Scots pine forests

“…Spore banks can be important in providing compatible ECM fungi to seedlings in temperate forests (e.g. Wen et al., ), but their roles in boreal forests are poorly known.…”

Soil propagule bank of ectomycorrhizal fungi associated with Masson pine (Pinus massoniana) grown in a manganese mine wasteland

“…densiflora and Betula maximowicziana [ 28 ], P . muricata in fire-disturbed forest soils [ 28 , 29 ], Pseudotsuga sinensis [ 30 ] and P . bungeana [ 31 ], but abundant in some pine forests at north America [ 10 ].…”