Production of ectomycorrhizal mycelium peaks during canopy closure in Norway spruce forests

Abstract

Summary• Here, species composition and biomass production of actively growing ectomycorrhizal (EM) mycelia were studied over the rotation period of managed Norway spruce (Picea abies) stands in south-western Sweden.• The EM mycelia were collected using ingrowth mesh bags incubated in the forest soil during one growing season. Fungal biomass was estimated by ergosterol analysis and the EM species were identified by 454 sequencing of internal transcribed spacer (ITS) amplicons. Nutrient availability and the fungal biomass in soil samples were also estimated.• Biomass production peaked in young stands (10-30 yr old) before the first thinning phase. Tylospora fibrillosa dominated the EM community, especially in these young stands, where it constituted 80% of the EM amplicons derived from the mesh bags. Species richness increased in older stands.• The establishment of EM mycelial networks in young Norway spruce stands requires large amounts of carbon, while much less is needed to sustain the EM community in older stands. The variation in EM biomass production over the rotation period has implications for carbon sequestration rates in forest soils.

Chemical changes in organic matter after fungal colonization in a nitrogen fertilized and unfertilized Norway spruce forest

“…Wallander et al (2010) found on average 70% ECM fungi in similar mesh bags without OM amendment in the same experimental site. However, the addition of compost in the present study resulted in a higher proportion of saprophytic fungi, and ECM fungi constituted 30-43% of the fungal abundance.…”

“…Fungal colonization and community composition of the mesh bags Colonization of sand-filled mesh bags is usually dominated by ECM fungi, although a lesser amount of saprotrophic fungi is also present (Wallander et al 2001(Wallander et al , 2010. Wallander et al (2010) found on average 70% ECM fungi in similar mesh bags without OM amendment in the same experimental site.…”

The production and turnover of extramatrical mycelium of ectomycorrhizal fungi in forest soils: role in carbon cycling

“…This occurs between 25 to 40 years of age in P. abies forests in central-southern Sweden (Schmalholz and Hylander 2009). The production of EMM seems to peak around the time when tree growth is highest (Wallander et al 2010;Kalliokoski et al 2010). …”

Ectomycorrhizal fungi contribute to soil organic matter cycling in sub-boreal forests

“…Hyphal in-growth cores or bags are commonly used (Wallander et al, 2001). These hyphae traps are usually filled with an inert substrate, such as sand, that minimizes colonization by saprotrophic fungi (Korkama et al, 2007;Lindahl et al, 2007;Wallander et al, 2010). In some cases, additional nutrient sources are added to ensure sufficient hyphal colonization or to evaluate the impact of limiting nutrients on EMF biomass production (Hagerberg and Wallander, 2002;Hagerberg et al, 2003;Hedh et al, 2008;Potila et al, 2009;Berner et al, 2012).…”