Stem trait spectra underpin multiple functions of temperate gymnosperm and angiosperm tree species

Abstract

A central paradigm in comparative ecology is that species sort out along a global economic strategy spectrum, ranging from slow to fast growth. Many studies evaluated plant strategy spectra for leaf traits, b u t few studies evaluated stem strategy spectra using a comprehensive set of anatomical, chemical and morphological traits, addressing key stem functions of different stem compartments (inner wood, outer wood and bark). This study evaluates how stem traits vary in the wood and bark of temperate tree species, and whether a slow-fast growth strategy spectrum exists and what traits make up this plant strategy spectrum. For 14 temperate gymnosperm and angiosperm species, 20 traits belonging to six key stem functions were measured for three stem compartments. Both across and within gymnosperms and angiosperms, a slow-fast stem strategy spectrum is found. Gymnosperms have slow traits and showed converging stem strategies because of their uniform tracheids. Angiosperms have fast traits and showed diverging stem strategies because of a wider array of tissues (vessels, parenchyma and fibers) and vessel size and arrangements (ring-porous versus diffuse porous). Gymnosperms showed a main trade-off between hydraulic efficiency and safety, and angiosperms showed a main trade-off between ‘slow’ diffuse porous species and ‘fast’ ring porous species. The slow traits of gymnosperms allow for a high hydraulic safety, an evergreen leaf habit and steady but slow growth makes them successful in unproductive habitats whereas the fast traits of angiosperms allow for high conductivity, a deciduous leaf habit and fast growth which makes them successful in productive habitats.

Stem traits, compartments and tree species affect fungal communities on decaying wood

“…Bark has a highly complex heterogeneous structure consisting of periderm, cortex and the (secondary) phloem (Srivastava, 1964; Harmon et al ., 1986), thus creating a high heterogeneity of microhabitats and more niche opportunities for different fungal species. Moreover, bark is rich in nutrients compared to wood tissues (Yang et al ., 2022), thus resulting in a higher fungal species richness (Weedon et al ., 2009; Bebber et al ., 2011; Kazartsev et al ., 2018). Additionally, Scolytinae, including bark and ambrosia beetles, may act as a vector for transporting fungal species into bark habitats, thereby contributing to a high fungal diversity in this compartment (Stokland et al ., 2012).…”

“…Though the two forests differ strikingly in soil conditions, i.e. sand versus clay, the growing conditions in the two forests had little effect on stem trait variation in harvested trees (Yang et al ., 2022). All tree logs were 100 cm long and had approximately the same diameter (c. 25 ± 3 cm), thus assuring a similar exposed surface area and substrate quantity.…”

“…Stem physical and chemical traits determine the accessibility and substrate quality of dead wood for different fungi, thereby impacting fungal diversity and composition (Fukasawa et al ., 2009; Rajala et al ., 2012; Purahong et al ., 2017). For example, angiosperm tree species differ from gymnosperm species in anatomical structure and lignin composition, which can be related to different fungal community compositions (Cornwell et al ., 2009; Kahl et al ., 2017; Yang et al ., 2022). Across tree species, defence traits (i.e.…”

“…Moreover, few studies have evaluated variation in fungal communities with respect to stem compartment (i.e. bark, sapwood and inner wood) despite the fact that they can strongly differ in wood anatomical and chemical traits (Yang et al ., 2022). Previous studies have generally been limited to 1–2 tree species (Kubartová et al ., 2012; van der Wal et al ., 2016) or yielded inconsistent results.…”

Dead wood is a source of life : Stem traits, fungal communities, and stem decomposition of temperate tree species

“…3.4c). Such a convergent pattern during succession also occurs for wood-inhabiting invertebrates (Zuo et al 2021). Possible reasons for the differences between clay and sandy sites could be that: i) species-specific endophytes present in living trees turned to be visible saprotrophs during early decay years (Parfitt et al 2010); ii) most gymnosperm species harvested from old sandy forest may have more endophytes than those angiosperm species from the young clay forest during long term succession (Frank and Pirttilä 2018); iii) the endophytes may switch to a pioneer strategy when logs are incubated in their home site (home-field advantage) (Baber et al 2016), while strong competition may occur when logs are incubated in the other site.…”