Root litter decomposition is suppressed in species mixtures and in the presence of living roots
Data files
Sep 27, 2023 version files 58.77 KB
Abstract
Plant species diversity and identity can significantly modify litter decomposition, but the underlying mechanisms remain elusive, particularly for root litter. Here, we aimed to disentangle the mechanisms by which plant species diversity alters root litter decomposition We hypothesised that 1) interactions between species in mixed communities result in litter that decomposes faster than litter produced in monocultures; 2) litter decomposition is accelerated in the presence of living plants, especially when the litter and living plant identities are matched (known as home field advantage).
Monocultures and a mixture of four common grassland species were established to obtain individual litter and a ‘natural’ root litter mixture. An ‘artificial’ mixed litter was created using litter from monocultures, mixed in the same proportions as the species composition in the natural litter mixtures based on qPCR measurements. These six root litter types were incubated in four monocultures, a four-species mixture, and an unplanted soil.
Root decomposition was strongly affected by root litter identity and the presence, but not diversity, of living roots. Mixed-species litter decomposed slower than expected based on the decomposition of single-species litters. In addition, the presence of living roots suppressed decomposition independent of the match between litter and living plant identities. Decomposition was not significantly different between the ‘natural’ and ‘artificial’ root litter mixtures, indicating that root-root interactions in species mixtures did not affect root chemical quality.
Synthesis: Suppressed decomposition in the presence of living roots indicates that interactions between microbial communities associated with living roots and root litter control root litter decomposition. As we found no support for the importance of home field advantage or interspecific root interactions in modifying decomposition, suppressed decomposition of mixed-species litter seems to be primarily driven by chemical rather than biotic interactions.
README: Root litter decomposition is suppressed in species mixtures and in the presence of living roots
https://doi.org/10.5061/dryad.6m905qg5r
There are two spreadsheets that include all data used for the data analysis for our study. The first spreadsheet has all data for the analysis of home-field advantage, priming effect, root litter decomposition, root traits, microbial communities and nutrient contents. The second spreadsheet has the data used to calculate expected and observed root litter decomposition based on the proportions in natural mixtures using qPCR.
Description of the data and file structure
Variable Abbreviation | Variable Abbreviation meaning |
---|---|
Ts | Treatment |
Pot | Pot number |
Block | Experimental block |
Litter_id | Litter organized as per species name and type of mixture<br>Ao= Anthoxanthum odoratum <br>Dg= Dactylis glomerata<br>Lv= Leucanthemum vulgare<br>Ra= Rumex acetosa<br>M= Natural mixture <br>Mix_art= Artificial mixture |
Litter_type | Litter organized as per monoculture, natural mixture and artificial mixture<br>Mono= monoculture <br>Mix_nat= Natural mixture<br>Mix_art= Artificial mixture |
Plant_community | Plant community organized as per planted species or bare soil. <br>Ao=Anthoxanthum odoratum<br>Dg= Dactylis glomerata<br>Lv= Leucanthemum vulgare <br>Ra= Rumex acetosa<br>Mix= Natural mixture <br>So= soil |
Soil | Variable used to calculate priming effect, using "plant" and "soil" to discriminate treatments.<br>plant = living plant community <br>soil= bare soil |
Plant_community_type | Plant community type<br>Mono= monoculture<br>Mix= mixture <br>soil= bare soil |
Home_away | "Home" when litter and plant community were the same. <br>"Away" when litter differed from plant community |
DWAB | Dried weight above biomass (grams) |
FWRB | Fresh weight root biomass (grams) |
DWRB | Dried weight root biomass (grams) |
prop_remain1 | Root litter proportion remaining in sampling point 1 |
prop_remain2 | Root litter proportion remaining |
Amo_H2O | Water extraction of ammonium (mg g-1 dry soil) |
Ni_KCL | KCl extraction of nitrate (mg g-1 dry soil) |
TN_H20 | Total nitrogen by water extraction (mg g-1 dry soil) |
K2S04_Fumigated | Nitrogen extraction with K2S04 solution after soil was fumigated with chloroform (mg g-1 dry soil) |
K2S04_Unfumigated | Nitrogen extraction with K2S04 solution from non fumigated soil (mg g-1 dry soil) |
MBN | Microbial Biomass-Nitrogen (mg g-1 dry soil) |
MBC | Microbial Biomass -Carbon (mg g-1 dry soil) |
MBratio | Microbial Biomass ratio calculated using MBN and MBC. |
DOC | Dissolve organic carbon (mg g-1 dry soil) |
TC | Total Carbon(mg g-1 dry soil) |
DIC | Dissolve inorganic carbon (mg g-1 dry soil) |
pH | pH measured in water |
RNC | Root nitrogen content (mg per gram dry soil) |
RCC | Root carbon content (mg per gram dry soil) |
C_N_ratio | root Carbon/ Nitrogen ratio |
total_PLFAs | Total PLFAs (nmol g-1) |
total_fungal | Total Fungi (nmol g-1) |
total_bacteria | Total Bacteria (nmol g-1) |
fungal_bacterial | Ratio fungi / bacteria |
total_gram_po | Total of Gram Positive Bacteria (nmol g-1) |
total_gram_ne | Total of Gram Negative Bacteria (nmol g-1) |
gram_ratio | Gram Bacteria Ratio |
Second sheet
Variable abbreviation | Variable abbreviation meaning |
---|---|
Plant_community | Living plant community where root litter was placed<br>Ao=Anthoxanthum odoratum<br>Dg= Dactylis glomerata<br>Lv= Leucanthemum vulgare <br>Ra= Rumex acetosa<br>Mix= Natural mixture <br>So= soil |
Treatment | All experimental unites belong to treatment testing the decomposition of artificial mixed root litters on each plant community.<br>Mix_art= Artificial mixture |
Block | Experimental block where the pot was placed |
Mix_ID | Specific artificial mixed root litter placed in each pot. Each mixture was created using the real proportions in natural mixed root litters obtained by qPCR analysis. |
Exp_prop_remain1 | Expected proportion of remain litter for sampling point one |
Obs_prop_remain1 | Observed proportion of remain litter for sampling point one |
obsexp_dif1 | Difference between observed and expected remain litter for sampling point one |
Exp_prop_remain2 | Expected proportion of remain litter for sampling point two |
Obs_prop_remain2 | Observed proportion of remain litter for sampling point two |
obsexp_dif2 | Difference between observed and expected remain litter for sampling point two |