TY  - JOUR
AB  - Clear-cutting is the main forest management method in boreal and hemiboreal forests, but recently its implementation has raised concerns due to its effects on biodiversity, including the soil fungal biota. Forest soil fungi have an important role as mycorrhizal symbionts, decomposers of organic material and root pathogens. There is conflicting information about the effect of clear-cutting and related management practices on fungal assemblages. We aimed to assess the factors that affect the assemblages of major fungal functional guilds (ectomycorrhizal, saprotrophic, pathogenic and yeast fungi) and the changes in soil fungal diversity and community composition after clear-cutting in Norway spruce and Scots pine (retention trees > 5 m3 per ha) stands, and compared the outcomes with alongside control sites (uncut stands). In addition, we tested the effect of the size of the clear-cut area, soil scarification and the forest regeneration method (planting and sowing) on soil fungi. The samples were collected from 50 different clear-cut sites and 50 control sites on two repeated sampling occasions: recently (0–6 months) cut and one year after clear-cutting. Based on high-throughput Illumina sequencing soil fungal communities were affected immediately after clear-cutting, resulting in significantly different fungal structure composition. Soil fungal diversity in both spruce and pine stands increased after one year post-cut compared to control sites, except the richness of ectomycorrhizal fungi in spruce sites. However, the fungal communities showed the highest similarity between control and one year post-cut sites based on principal coordinates (PCO) and Permanova analyses. Nonetheless, relative abundance of ectomycorrhizal (EcM) fungi declined, whereas that of saprotrophs and pathogens increased. In spruce sites, saprotrophic fungi were negatively affected by soil scarification, but this was not evident in pine sites. Forest regeneration by planting after clear-cutting in pine sites resulted in higher ectomycorrhizal fungal richness compared to sowing. Size of the clear-cut area (ranging from 0.4 to 3.1 (5.0) ha) did not affect soil fungal diversity in spruce- and pine-dominated sites. We demonstrated that fungal community composition may recover within one year after clear-cutting in pine- and spruce-dominated hemiboreal forest stands. However, understanding the long-term effects of management on patterns and shifts in fungal biota needs a long-term study.
AU  - Rahn, E.*
AU  - Tedersoo, L.*
AU  - Adamson, K.*
AU  - Drenkhan, T.*
AU  - Sibul, I.*
AU  - Lutter, R.*
AU  - Anslan, S.*
AU  - Pritsch, K.
AU  - Drenkhan, R.*
C1  - 68463
C2  - 53655
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Rapid shift of soil fungal community compositions after clear-cutting in hemiboreal coniferous forests.
JO  - Forest Ecol. Manag.
VL  - 544
PB  - Elsevier
PY  - 2023
SN  - 0378-1127
ER  - 

TY  - JOUR
AB  - Mixed stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) frequently over-yield, when compared to respective monospecific stands. Over-yielding is attributed to enhanced resource uptake efficiency through niche complementarity alleviating species competition, for example through enhanced root stratification in mixture. Under severe and frequent summer drought, however, water limitation may become crucial in modifying the prevailing competitive interaction in mixed beech-spruce forests. We hypothesize, therefore, that under drought (H I) inter-specific interaction with beech reduces water accessibility for spruce more than intra-specific conditions, thus (H II) exacerbating drought susceptibility of spruce in terms of reduced photosynthesis and stem growth. Reactions at the organ (leaf, fine root), tree and stand scale were analysed in a mature forest with beech-spruce group mixture. Under inter-specific conditions spruce's fine-root production and depth of water uptake (assessed via δ18O of xylem water) shifted to shallow, drought-prone soil horizons, in agreement with H I. Overall, lowered fine root production and ramification along with a reduction in long-distance explorative ectomycorrhizal types resulted in decreased soil exploitation in spruce when growing together with beech. Spruce's drought sensitivity was exemplified by a distinct decrease in stomatal conductance, net CO2 uptake rate and stem growth during periods of water limitation. Notwithstanding, species interaction effects were absent in leaf gas exchange and stem diameter growth, during a six-week summer drought period in 2013 as well as in the extremely dry year of 2003, hence rejecting H II. Based on results from soil moisture measurements and water uptake depth, we interpret the conflicting findings for H I and H II to result from: (i) seasonal shifts between positive (during spring drought) and negative (during summer drought) effects of beech neighbourhood on soil water availability for spruce, possibly overriding each other in their effect on annual stem diameter growth and (ii) the group-wise mixture pattern, where spruce is exposed to competition with beech only along group edges, i.e. laterally only, so that the putatively adverse beech effect on water accessibility stays limited. Our results suggest, compared to single tree mixture, group-wise mixture of beech and spruce to be a favourable silvicultural option in the face of climate change.
AU  - Goisser, M.*
AU  - Geppert, U.
AU  - Rötzer, T.*
AU  - Paya, A.*
AU  - Huber, A.*
AU  - Kerner, R.C.
AU  - Bäuerle, T.*
AU  - Pretzsch, H.*
AU  - Pritsch, K.
AU  - Häberle, K.H.*
AU  - Matyssek, R.*
AU  - Grams, T.E.E.*
C1  - 48840
C2  - 41460
CY  - Amsterdam
SP  - 268-278
TI  - Does belowground interaction with Fagus sylvatica increase drought susceptibility of photosynthesis and stem growth in Picea abies?
JO  - Forest Ecol. Manag.
VL  - 375
PB  - Elsevier Science Bv
PY  - 2016
SN  - 0378-1127
ER  - 

TY  - JOUR
AB  - Top dieback on Norway spruce has frequently occurred in stands of southern Norway and it is a serious threat to the productivity and stability of economically important spruce stands. The underlying dieback mechanisms are unclear; often the whole stand is not affected, but only individual trees. Drought stress is hypothesized as a crucial trigger for the onset of symptoms; therefore, we studied the response-effect relationships of water limitation and tree specific traits. We analyzed year ring anatomy, i.e. wood density, as an estimate of drought vulnerability, and carbon and oxygen isotope composition of the year rings as an estimate of leaf physiology. At two sites in SE Norway, we grouped declining and symptomless trees in direct vicinity of each other into pairs for comparison of anatomical and physiological traits. For one site, we observed a distinct lower wood density and higher radial growth of declining trees in comparison with the healthy trees over several years. We identified high vulnerability to cavitation due to lower wood density as a trait of individuals prone to dieback. We observed lower intrinsic water-use efficiency (WUEi) associated with increased stomatal conductance. The healthy trees had lower stomatal conductance, which most likely prevented water losses during dry periods. Within a population, we observed a trade-off between long-term growth performance under “average” conditions and a different response for “extreme” events. These resource strategies will be important for Norway spruce management, especially for regions facing an increase in the frequency of drought events.
AU  - Hentschel, R.
AU  - Rosner, S.*
AU  - Kayler, Z.E.*
AU  - Andreassen, K.*
AU  - Børja, I.*
AU  - Solberg, S.*
AU  - Tveito, O.E.*
AU  - Priesack, E.
AU  - Gessler, A.*
C1  - 31069
C2  - 34149
CY  - Amsterdam
SP  - 27-36
TI  - Norway spruce physiological and anatomical predisposition to dieback.
JO  - Forest Ecol. Manag.
VL  - 322
PB  - Elsevier Science Bv
PY  - 2014
SN  - 0378-1127
ER  -