Data from: Fine root presence and increased phosphorus availability stimulate wood decay in a Central Amazonian rainforest
Data files
Nov 13, 2023 version files 37.15 KB
Abstract
In the Amazon basin, approximately 60% of rainforest thrives on geologically old and highly weathered soils, thus decomposition represents an important mechanism for recycling nutrients from organic matter. Although dead logs and branches constitute up to 14% of the carbon stored in terrestrial ecosystems, woody debris decomposition and mainly the effect of direct nutrient cycling by plant root interaction is poorly studied and often overlooked in ecosystem carbon and nutrient budgets. Here we monitored the decomposition of five different local woody species covering a range of wood density by conducting a long-term wood decomposition experiment over two years with factorial root presence and phosphorous (P) addition treatments in a Central Amazonian rainforest. We hypothesized that woody debris decomposition is accelerated by colonizing fine roots mining for nutrients, possibly strongly affecting wood debris with lower density and higher nutrient concentration (P). We found that root colonization and P addition separately increased wood decay rates, and although fine root colonization increased when P was added, this did not result in a change in wood decay. Nutrient loss from wood was accelerated by P addition, whereas a root presence effect on nutrient mobilization was only detectable at the end of the experiment. Our results highlight the role of fine roots in priming wood decay, although direct nutrient acquisition by plants seems to only occur in more advanced stages of decomposition. On the other hand, the positive effect of P addition may indicate that microbial nutrient mobilization in woody material is driven mainly by wood stoichiometry rather than priming by root activity.
README: Fine root presence and increased phosphorus availability stimulate wood decay in a Central Amazonian rainforest
https://doi.org/10.5061/dryad.rr4xgxdfj
This dataset was obtained by a wood decomposition experiment conducted over two years in the Central Amazonian. We text the influence of fine root colonization and P availability on the wood debris decomposition of five different species. After each collection, we obtained variables that represent the mass loss, nutrient content, and root colonization.
Description of the data and file structure
We have only one data file that contains the data before any analysis or calculation. The file was structured by all response variables on the column obtained by the different species and treatment of each collection time on the lines.
Title of the Data Table: “Data_wood_decomposition_experiment”
Description: This dataset contains the complete data of a wood decomposition experiment carried in the Central Amazonian tropical forest over two years (June 2016 to July 2018).
Number of Rows: 226
Number of Columns: 25
Data Collection Period: June 2016 to July 2018
Column Names:
date_collection; days_incubation; species; sample_number; block; root_treatment; fertilization_treatment; months; diameter_I; diameter_II; length; initial_weigth; weight_65C; final_fresh_weight; weight_immersion_volume; finish_weight; root_weight; P; K; Ca; Mg; N; cellulose; lignin.
Column Descriptions:
- date_collection: data of the sample collection in the field.
- days_incubation: Period of days that the samples remained in the field
- species: the genus identification of the species used in the experiment.
- sample_number: identification number of each sample
- block: number of the blocks of which samples were allocated in the field. The design is distributed in two large blocks (1 and 2). "none" refers to samples that were not installed in the field (controls).
- root_treatment: treatment that refers to root colonization on wood debris. Where: "none" refers to samples that were not installed in the field (controls); “with” treatment that permits root presence/colonization; “without” treatment without root presence (every 15 days all root was manually removed from the wood debris in the field).
- fertilization_treatment: treatment that refers to P addition. Where: "none" refers to samples that were not installed in the field (controls). “with” refers to the addition of P solution every 15 days; “Without” refers to no P solution addition.
- months: months of respectively collected after the installation of the experiment.
- diameter_I and diameter_II: Measurements of the diameter of the samples used, taken at both ends. Measurements were carried out with the aid of a digital caliper (mm) on all samples (controls and used to set up the experiment in the field).
- length: Length measurements were carried out only in control samples (not installed in the field).
- initial_weigth: Initial fresh weight of each sample (g). Weighing was carried out after cutting the wood debris and before carrying out the first fertilization procedures (details described in the manuscript).
- weight_65C; Dry weight of each sample (g). Samples were dried and weighed after carrying out the first fertilization procedures. *Drying was carried out in an air circulation oven at 65°C until constant weight was reached (approximately 72 hours).
- final_fresh_weight: Fresh weight of each wood sample immediately after collection (g). Weighing was carried out after removing the roots present in the wood debris related to them with root treatment.
- weight_immersion_volume: Weight of samples immersed in water (g). The objective is to use volume to calculate density.
- finish_weight: wood samples final dry weight. The samples were dried in an air circulation oven at 65°C until they reached a constant weight.
- root_weight: dry weight of the roots taken from the samples referring to the treatment that allowed the proliferation of fine roots (g). All roots found in each sample were removed using tweezers and dried in an air circulation oven at 65°C.
- P: wood debris phosphorus concentration expressed in g kg-1.
- K: wood debris potassium concentration expressed in g kg-1.
- Ca: wood debris calcium concentration expressed in g kg-1.
- Mg: wood debris magnesium concentration expressed in g kg-1.
- N: wood debris nitrogen concentration expressed in g kg-1.
- Cellulose: wood debris cellulose concentration expressed in %
- Lignin: wood debris lignin concentration expressed in %
NA values description
Lines 2 to 26 represent the baseline data, that is, parameters that were evaluated in the wood debris before installing the experiment. Therefore, the NA values for columns “final_fresh_weight”; “weight_immersion_volume”; “finish_weight”; “root_weight” in this range (rows 2 through 26) represent non-existent data because these are analyzed after each collection.
The “without” treatment in column “root_treatment” means that roots were not allowed to colonize the wood debris. Therefore, we have NA values for root biomass in column “root_weight” in the respective lines of the without root treatment.
Cellulose and lignin concentrations (columns: cellulose; lignin) in wood debris were analyzed only for the baseline and collections after 3, 12, and 24 months. The NA data for the other collections refers to unanalyzed material (i.e., no data).
The other NA values refer to the absence of data due to some problem in the field or laboratory that made it impossible to obtain the results.
Methods
The data was collected over a two-year wood decomposition experiment in the Central Amazon Forest. After every collection laboratory analyses were conducted to obtain the variables used in the manuscript. The data was checked and processed using the software R.