CSPs: Leaf litter decomposition in CSPs: remaining litter mass, carbon and nitrogen concentration during decomposition

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Dataset Abstract

This data set set belongs to the SP5 litter decomposition experiment that was structured in three parts. First we determined single-species litter decomposition constants of 26 woody species, second litter decomposition of Schima superba was assessed in all 27 CSPs to reveal inter-plot variability using a common standard litter substrate, and third litter diversity was manipulated in 27 plot-specific litter mixtures with species richness ranging from 7 - 17 species. In this dataset remaining mass, nitrogen and carbon concentration für each bag and time step are reported. Please find detailed information below.

Dataset Design

Litter bags (15 cm x 15 cm) were made of nylon with 1 mm mesh size and filled with 5 g of dried leaf litter. The decomposition experiment was started in spring 2009. After carefully removing loose forest floor litter, bags were slightly anchored in 5 cm spacing at the ground with 10 cm long metal stakes puncturing the hem. Because an organic humus layer (Oh) was often absent, litter bags were placed directly on the mineral soil in most cases. Gaps between litter bags were refilled with the removed forest floor litter. Replicated litter bags were retrieved in six time steps after 92, 146, 205, 272, 333 and 383 days of decomposition in the field. Because CSPs were spread over the entire GNNR, litter bag retrieval took about seven days to finish. Thus, the given time intervals represent the mean number of days calculated for each sampling period after the start of the experiment. After retrieval, remaining litter was carefully cleaned from adherent mineral soil, ingrown roots and fecal matter, dried at 60 °C until constant mass and weighed after cooling down. We used three complementary approaches to study leaf litter decomposition (s. decription below).

(i) Decomposition of single-species leaf litter ("single_species"
We determined litter decomposition rate of 26 sub-canopy and canopy tree species occurring in the CSPs under the same microclimatic and edaphic conditions. For each species, 12 litter bags were filled with dried leaf litter, and two replicated bags per species were retrieved at each time step. Owing to the large coverage (several square meters of forest floor) by litter bags, we decided not to conduct the experiment within a selected CSP but rather outside on undisturbed forest floor providing enough space. Hence, litter bags were placed on the ground a few metres next to one plot (CSP 9) in two blocks containing one replicated bag for each time step, respectively. Random arrangement of the 156 bags in each block ensured that species-specific decomposition rates were not affected by spatial variation of microclimatic conditions.

(ii) Decomposition of Schima superba leaf litter ("common_substrate")
Leaf litter collected from one of the most dominant and abundant tree species (Schima superba) was used to study plot-specific litter decomposition along the tree diversity and successional forest gradient using a total number of 324 litter bags. 12 bags filled with Schima superba leaf litter were placed in every plot with 2 bags to be sampled at each of the 6 retrieval events. Bags were randomly positioned within an area of 1 m by 2 m in the central subplot of the corresponding CSP.

(iii) Decomposition of mixed-species leaf litter ("mixed_litter")
In the litter mixture approach, the number of litter species per bag equalled the number of species found in the different CSPs based on 24 species for which sufficient quantities of litter could be collected. Hence, species number in plot-specific litter mixtures ranged from 7 to 17 with 0.294 g to 0.714 g of leaf litter per species contained in each bag, respectively (Appendix Table 4). Litter bag species richness was significantly related to plot species richness (Appendix Fig. 10). For each plot, 12 bags filled with a plot-specific mixture were prepared and placed next to the Schima superba litter bags in each CSP covering together an area of about 2 m2. After retrieval, separation into single species was not possible due to the large number of species involved and high fragmentation during decomposition. However, we managed to differentiate between broad-leaved and coniferous litter (Pinus massoninana, Pinus taiwanensis and Cunninghamia lanceolata). Dry mass was determined separately for broad and needle-leaved litter.

Spatial Extent

CSPs of the BEF China Experiment, Gutianshan Nature Reserve
29°08-29°17'N
118°02'-118°11'E

Temporal Extent

from spring 2009 one year

Taxonomic Extent

Leaf litter from trees

Measurement Circumstances

1) For Castanopsis tibetana the second replicated litter bag could not be relocated for time step 92 days (here only one litter bag retrieved) but was rediscovered at time step 146 days (here 3 litter bags retrieved).
2) In some bags caterpillars were discovered that consumed a large fraction of litter material (e.g. Castanopsis tibetana). As we used a mesh size if 1 mm, caterpillars hatched from eggs but could not escape anymore from the litter bags, thus reflecting unnatural conditions. For calculating k-values those litter bags with abnormal mass loss were excluded.

Data Analysis

This data set lists all measurements for each litter bag. Calculated decomposition constants (k-values) for each species can be found in the k-values dataset "Leaf litter decomposition in Gutianshan: decomposition rates (k-values)"

Paper proposal submissions

Published

2017

2016

Data columns available in the raw data part of this dataset

Study_Part
Experimental design: this data is used for single litter bags and mixed litter bags; single_species; common_substrate; mixed_litter
Data group: Helper
Values
litter_mixture
common_substrate
single_species
Species_acr
Species acronym in single species litter bags
Data group: Helper
Values
Casfar
Cashen
Adimil
Caseyr
Camche
richness
Species richness in mixed litter bags
Unit: count
Data group: Litter diversity
Keywords: species richness, explanatory, diversity
Values
10
12
13
1
11
Species
Species name
Data group: Scientific plant species name
Keywords: species
Values
Camellia chekiangoleosa
Castanea henryi
Castanopsis fargesii
Adinandra millettii
Castanopsis eyrei
Days
Duration of litter bag exposure in days
Unit: days
Data group: Exposure time
Keywords: duration, exposure time
Values
333
205
272
0
146
Block
Hence, litter bags were placed on the ground a few metres next to one plot (CSP 9) in two blocks containing one replicated bag for each time step, respectivel
Data group: Helper
Keywords: location
Values
1
2
CSP
Number of the Comparative Study Plot; Datagroup description: BEF research plot name; Datagroup description: Reasearch plots of the Biodiversity - Ecosystem functioning experiment (BEF-China). Comparative Study Plots (CSP) in the Gutianshan Nature Reserve, having a size of 30x30m^2, measured on the ground.
Data group: BEF research plot name
Keywords: location
Values
CSP01
CSP02
CSP04
CSP03
CSP05
Number_bag
Number of litter bag
Data group: Helper
Keywords: object
Values
10
102
100
1
101
Mass
Mass remaining from the initial 5g of litter
Unit: gram
Data group: Litter Biomass
Keywords: response variable, biomass, litter
Values
0.854
1.447
1.346
1.146
0.71
PercentMass
Percent of initial mass; Calculation: (remaining Mass / 5 g) * 100%
Unit: percent
Data group: Decomposition
Keywords: decomposition
Values
14.2
26.92
100
22.92
17.08
Carbon
Carbon concentration; C/N Analyzer Elemental Analyzer (PE 2400 II CHN Elemental Analyser, Perkin-Elmer, Boston, MA, USA) Lab: Jin-Sheng He
Unit: percent
Data group: Carbon
Keywords: carbon
Values
36.49
34.55
35.99
36.23
35.87
Nitrogen
Nitrogen concentration; C/N Analyzer Elemental Analyzer (PE 2400 II CHN Elemental Analyser, Perkin-Elmer, Boston, MA, USA) Lab: Jin-Sheng He
Unit: percent
Data group: Nitrogen
Keywords: nitrogen
Values
0.52
0.59
0.56
0.58
0.54
CN
C:N ratio
Unit: ratio
Data group: Carbon Nitrogen ratio
Keywords: C/N ratio
Values
23.39664804469274
19.914893617021274
23.795121951219514
22.904761904761905
23
Cunlan
mass of Cunninghamia lanceolata in mixed species bags
Unit: gram
Data group: Litter Biomass
Keywords: biomass
Values
0.145
0.175
0
0.171
0.164
Pinus
mass of Pinus massoniana and Pinus taiwanensis in mixed species bags
Unit: gram
Data group: Litter Biomass
Keywords: biomass
Values
0.145
0.148
0
0.119
0.163
Cunlat_Pin
Sum of Cunninghamia and Pinus
Unit: gram
Data group: Litter Biomass
Keywords: biomass
Values
0.197
0.179
0.168
0.2
0
Percentgymno
Percent of remianing Gymnosperms (Cunninghamia + Pinus) in the litter mixture related to initial mass of gymnosperm litter in the mixture
Unit: percent
Data group: Helper
Values
100
46.96485623003195
38.32
0
49.82993197278912