Pilot experiment: tree sapling biomass allocation to strata

Usage Rights

This data is Free for public.

Permission is granted to anybody to access, use and publish all open for public data freely. The commercial use of any data is prohibited. The quality and completeness of data cannot be guaranteed. Users employ these data at their own risk. In order to make attribution of use for owners of the data possible, the identifier of ownership of data must be retained with every data record. Users must publicly acknowledge, in conjunction with the use of the data, the data owners. Cite the data as follows: Lang, A., von Oheimn, G. and Härdtle, W. (2013): Competition of tree saplings -Pilot- Biomass of target saplings - biomass allocation to strata. BEF-China data portal (Accessed through URL http://china.befdata.biow.uni-leipzig.de/datasets/145)

Dataset Abstract

Questions: One tenet of biodiversity and ecosystem functioning research is the dependence of ecosystem functions on species-specific differences in traits. Community assembly theory predicts niche differentiation among the constituent species, for which there is as yet no empirical evidence for subtropical forest ecosystems.We thus ask:
(1) Which mechanisms promote sapling coexistence in the four abundant early-successional subtropical species Schima superba, Elaeocarpus decipiens, Quercus serrata and Castanea henryi?
(2) Do species richness, species composition, species identity and stand density have an impact on growth patterns and crown architecture of tree saplings?

Dataset Design

In a field experiment, we manipulated the local neighbourhood of saplings with regard to species richness (1, 2 and 4 species), species composition (monocultures, six two-species combinations and one four-species combination) and stand density (low, intermediate and high).

Spatial Extent

Pilot Experiment
29°06'N
117°55' E

To analyse biomass allocation patterns with regard to stratification (i.e. height layers) and to different constitutents (stem, branches and leaves), the four central individuals per plot were harvested in September 2010 in 50 cm strata starting from ground. Saplings were divided into stem, branches and leaves for each stratum. Biomass was dried at 70° C for 48 h and weighed to 0.01 g precision. Biomass data were logarithmically transformed prior to analyses.To analyse the vertical above-ground biomass distribution, we calculated the cumulative biomass fraction C, i.e. the proportion of cumulative above-ground biomass, summed up from the ground to the height strata hs (50, 100, 150, 200, 250 cm).

Published

Mechanisms promoting tree species coexistence:
Experimental evidence with saplings of subtropical forest ecosystems of China
;submitted to JVS (This dataset represents only one part of the analyses for the mentioned manuscript)

Temporal Extent

trees have been planted in 2009 and harvested in autumn 2010

Taxonomic Extent

4 Species: Schima superba, Elaeocarpus decipiens, Quercus serrata, Castanea henryi

Measurement Circumstances

The medium density plots of block 4 were harvested in July 2010 by SP1.

Data Analysis

The overall aim of this study was to disentangle neighbourhood effects on growth, biomass allocation, crown architecture and branch demography of saplings. Firstly, the complete dataset was used to test for diversity effects by fitting mixed effects models (Model 1) including species richness and density as factorial variables and the initial diameter as fixed effect. The initial diameter was used to account for differences in size at the beginning of the experiment. Secondly, all two species combinations were analysed for species composition. Mixed effects models (Model 2a) were fitted using species composition, density and initial diameter as fixed effect. The analyses with Model 2b were performed for the high density treatment data divided by species to exclude density effects and to test for composition effects on the individual-level of each species. Model 2b contained species composition and initial diameter as fixed effects. Thirdly, mixed effects models (Model 3) for all monocultures were calculated to test for species identity. They were fitted by the predictor variables species identity, density and initial diameter as fixed effects. Random effects for all models were plot nested in block. Model simplification was performed by stepwise backward selection of fixed factors, removing the least significant variables until only significant predictory variables remained (p < 0.05). The significant categorical variables were further examined by a Tukey post-hoc test.

Data columns available in the raw data part of this dataset

plot_id
Individual complex ID for identifying exactly each plot; it connects with underline character the block number and the community code, i. e. the block number with the plots treatment. The plot identifier contains the information, which block the plot is in and which community is is comprised of.
Data group: BEF research plot name
Keywords: Pilot experiment
Values
2_AE05
2_AE02
2_AE01
2_AE04
2_AE03
species_diversity
tree species diversity level within the pilot plot
Data group: Taxonomic biodiversity
Keywords: biodiversity, diversity treatment
Values
2
1
4
species_code
2-character abbreviation encoding the species name and epithet of the tree species located within the plot
Data group: Species community code in the pilot experiment
Keywords: species
Values
ch_ed
ch_ed_qs_ss
ch
ch_qs
ch_ss
species_combination
unique species combination code as number
Data group: Helper
Values
1
3
10
2
11
Ind_pos
number of individual, Individuals were consecutively numbered starting from the SW corner of the plot
Data group: Individual position within Pilot experiment
Values
6
7
1
11
10
Code
individual related unique code
Data group: Individual related unique code for the Pilot experiment
Keywords: tree individual, tree position
Values
1AE02_06
1AE01_07
1AE01_11
1AE01_10
1AE02_07
density
density of planted saplings, Saplings were planted in low, medium and high density. The low density treatment was one individual per plot. The medium and high density treatment comprised 16 individuals, planted with 25 cm and 15 cm planting distance respectively.
Data group: Density class
Keywords: competition, abundance
Values
medium
low
high
Spp
species identity of individual
Data group: Scientific plant species name
Keywords: species
Values
Elaeocarpus decipiens
Castanea henryi
Quercus serrata
Schima superba
hs
height stratum from ground
Data group: Vegetation layer height
Keywords: height
Values
s2
s4
s3
s1
s5
l.fresh
leaf biomass fresh per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: fresh weight, aboveground biomass
Values
0
0.11
0.1
0.07
0.08
l.dry
leaf biomass dry weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: biomass, leaf, dry weight
Values
0.05
0.06
0.04
0.03
0
b.fresh
branch biomass fresh weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: branch, fresh weight, aboveground biomass
Values
0.04
0
0.05
0.08
0.17
b.dry
branch biomass dry weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: biomass, branch, dry weight
Values
0.07
0.02
0.03
0
0.05
s.fresh
stem biomass fresh weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: stem, fresh weight, aboveground biomass
Values
0.23
0.18
0.14
0
0.28
s.dry
stem biomass dry weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: biomass, stem, dry weight
Values
0.1
0
0.16
0.06
0.13
tot.bio.fresh
total biomass fresh weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: fresh weight, aboveground biomass
Values
0.45
0
0.89
0.81
0.55
tot.bio.dry
total biomass dry weight per stratum
Unit: g
Data group: Above and below ground biomass measurement
Keywords: biomass, tree performance, tree, dry weight
Values
0.32
0.43
0
0.29
0.41
C
cumulative biomass dry weight per stratum
Unit: g
Data group: Cumulative proportion of biomass from ground along strata
Keywords: biomass allocation
Values
0.269828179
0.266843745
0.25866649
0.270359239
0.274185612
gbd_T0
ground basal diameter at time of planting; asal diameter was measured (5cm above ground) at the time of planting (March 2009).
Unit: mm
Data group: Basal diameter
Keywords: tree performance, basal diameter
Values
14
13
10
1
11