Stem decomposition of temperate tree species is determined by stem traits and fungal community composition during early stem decay
Data files
Mar 13, 2024 version files 431.89 KB
Abstract
Dead trees are vital structural elements in forests playing key roles in the carbon and nutrient cycle. Stem traits and fungal community composition are both important drivers of stem decay, and thereby affect ecosystem functioning, but their relative importance for stem decomposition over time remains unclear.
To address this issue, we used a common garden decomposition experiment in a Dutch larch forest hosting fresh logs from 13 common temperate tree species. In total 25 fresh wood and bark traits were measured as indicators of wood accessibility for decomposers, nutritional quality, and chemical or physical defense mechanisms. After one and four years of decay, we assessed the richness and composition of wood-inhabiting fungi using amplicon sequencing and determined the proportional wood density loss.
Average proportional wood density loss for the first year was 18.5%, with further decomposition occurring at a rate of 4.3% yr-1 for the subsequent three years across tree species. Proportional wood density loss varied widely across tree species in the first year (8.7-24.8% yr-1) and subsequent years (0-11.3% yr-1). The variation was directly driven by initial wood traits during the first decay year, then later directly driven by bark traits and fungal community composition. Moreover, bark traits affected the composition of wood-inhabiting fungi and thereby indirectly affected decomposition rates. Specifically, traits promoting resource acquisition of the living tree, such as wide conduits that increase accessibility and high nutrient concentration, increased initial wood decomposition rates. Fungal community composition, but not fungal richness explained differences in wood decomposition after four years of exposure in the field, where fungal communities dominated by brown-rot and white-rot Basidiomycetes were linked to higher wood decomposition rate.
Synthesis. Understanding what drives deadwood decomposition through time is important to understand the dynamics of carbon stocks. Here, using a tailor-made experimental design in a temperate forest setting, we have shown that stem trait variation is key to understanding the roles of these drivers; Initially, wood traits explained decomposition rates while subsequently, bark traits and fungal decomposer composition drove decomposition rates. These findings inform forest management with a view to selecting tree species to promote carbon storage.
README: Stem decomposition of temperate tree species is determined by stem traits and fungal community composition during early stem decay
https://doi.org/10.5061/dryad.qrfj6q5pw
Description of the data and file structure
The dataset consists of three files, including:
"Data.xlsx", consists of five sheets
a) Sheet1 is the basic information of the data
b) Sheet “Data1” is used to plot Fig. 1 (Proportional wood density loss varies across 13 tree species at two decay periods, the first year T0-T1 (WDL01) and three follow-up years T1-T4.)
c) Sheet “Data2&3” are used to plot Fig. 2 (Principal component analyses showing the associations among multiple wood and bark traits of 13 tree species and showing how wood-inhabiting fungi vary among 13 tree species at two decaying periods: T1 and T4.)
d) Sheet “Data4” is used to plot Fig. 3 (Relationships between proportional density loss of 13 tree species and wood and bark trait values, after one year (T1) and between decay year one and four (T1-T4).)
e) Sheet “Data5” is used to plot Fig. 4 (Structural equation models for the effects of initial stem traits (wood and bark) and fungal decomposers on wood density loss of 13 species.)
"List_of_tree_species.txt" defines species abbreviations
"List_of_variables.txt" defines variable abbreviations
Sharing/Access information
Sequence data associated with this dataset is deposited in the National Center for Biotechnology Information’s Short Read Archive under BioProject PRJNA768246, https://dataview.ncbi.nlm.nih.gov/object/PRJNA768246.
Methods
We took advantage of the LOGLIFE project (Cornelissen et al. 2012), in which freshly cut stems of 13 temperate tree species were left to decompose in a common garden experiment. Ten tree species were incubated in February 2012, and three tree species were added in February 2015. Firstly, five individual trees were cut for each tree species and distributed to five blocks (i.e. forest plots) to decay. From trunk parts without major side branches five logs were cut per individual tree and treated as replicates, each with 1 m length and a diameter of 25 ± 3 cm, thus assuring a similar exposed stem cross-sectional area and substrate volume accessible to decomposers. These logs obtained from the same tree shared similar physical-chemical traits. One of the five logs was randomly harvested after one and four years of decay, respectively, and used for wood density measurement and molecular sampling. Corresponding data are archived here.