Traits associated with the conservation gradient are the strongest predictors of early-stage fine root decomposition rates
Data files
Sep 23, 2024 version files 63.08 KB
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JECOL_Code_Version_4.R
41.66 KB
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nzRootDecomp.csv
6.47 KB
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README.md
3.52 KB
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root.trait.means.csv
7.86 KB
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rootChem.csv
1.21 KB
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species-tree_for_Daniel_Laughlin.nwk
2.36 KB
Abstract
Fine root traits span two independent axes of variation, the conservation and collaboration axes, which define the root economic space (RES). However, whether early-stage fine root decomposition rates (quantified as proportion mass loss, i.e., pml) are more strongly related to collaboration or conservation traits remains unclear.
We studied 63 tree species in New Zealand's temperate rain forest. We determined the phylogenetic signal in pml and fine root traits, conducted phylogenetic principal component analysis, and used phylogenetic generalized least squares to determine which traits are most strongly related to pml.
Root decomposition exhibited a high phylogenetic signal and was more strongly related to the conservation than the collaboration axis. Root tissue density (RTD) was negatively correlated and root nitrogen (RN) was positively correlated with pml. Root diameter was positively yet weakly correlated with pml, but specific root length was uncorrelated with pml. The lignin-to-N ratio and root cellulose were the strongest predictors of pml.
Synthesis. Early-stage fine root decomposition is most strongly driven by tissue quality traits, such as root nitrogen, tissue density, and lignin-to-N ratio, which all align with the conservation axis of the root economics space. However, root diameter plays a weak yet undeniable role in early-stage fine root decomposition. Some thick-rooted species decomposed faster, possibly due to the higher-quality cortical tissue. Thin rooted species decomposed slower, possibly because of their higher cellulose concentration that maintains the structural integrity of small-diameter roots. Relationships between decomposition and other traits that align with the collaboration gradient deserve further study across the phylogeny of vascular plants.
https://doi.org/10.5061/dryad.vhhmgqp3g
Description of the data and file structure
Traits associated with the conservation gradient are the strongest predictors of early-stage fine root decomposition rates.
The dataset presented here was analyzed to support our paper with the title above. In this paper, we found that traits on the conservation axis of the root economics space are more closely related to fine root decomposition than traits on the collaboration axis. We also found that thick-rooted species exhibit faster decomposition due to their higher quality cortical tissues and thin-rooted species with high cellulose content that provide support for small-diameter roots decompose slowly.
The nzRootDecomp.csv file contains the decomposition dataset. The root.trait.means.csv file has the functional root traits data and rootChem.csv has the root chemistry trait data. The species phylogeny data is in the species-tree for Daniel Laughlin.nwk file. The columns or variables used in the analyses are described under each data file below.
Files and variables
File: nzRootDecomp.csv
Description: nzRootDecomp.csv contains 172 rows with each observation describing the incubated fine root samples’ initial and final dry weights.
Variables
- Species: shows the species
- Rep: indicates the number of replicates
- Tag #: shows the tag used for each sample during the experiment
- Dry weight initial: shows the initial weight of the incubated samples (g)
- Final dry weight: denotes the final weight of the incubated samples (g)
- proportion mass loss: denotes the calculated values of the proportional mass loss for each species.
File: root.trait.means.csv
Description: root.trait.means.csv contains 66 rows and each observation shows the plant functional trait values, species’ code, mycorrhizal, and phylogenetic information of each species.
Variables
- species: shows the species
- srl: specific root length (m/g)
- rootdiam: root diameter (mm)
- rdmc: root dry matter content (mg/g)
- branch: root branching index (tips/root length)
- rootn: root nitrogen (%)
- rtd: root tissue density (mg/mm^3)
- rootp: root phosphorus (%)
- spcode: shows the species code
- mycor: mycorrhizal type
- phylo: phylogeny
File: rootChem.csv
Description: rootChem.csv files contain 49 rows; each observation indicates the root chemistry traits of the species.
Variables
- species: shows the species
- r.fibre: root fibre (%)
- r.cellulose: root cellulose (%)
- r.lignin: root lignin (%)
- r.tannins: root tannins (%)
- r.phenol: root phenol (%)
The empty cells means we do not have the relevant data for those species
File: species-tree for Daniel Laughlin.nwk
Description: species-tree for Daniel Laughlin.nwk contains the phylogenetic relationships among the tree species.
Code/software
The R script ‘JECOL Code_Version 4.R’ contains the code for all data manipulation, analyses, and figures presented in the paper and supplementary figures.
Access information
Other publicly accessible locations of the data:
- The dataset can be retrieved from https://github.com/CONFIDENCESKT/Fine-Root-Decompositon_Postdoc/tree/main/data