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Title:
Main Experiment: Removal experiment – predictor variables
Access rights:
Free within projects
Usage rights:
BEF-China: SP11 internal
Published:
No information available
Abstract:
SP 11 studied the interaction between tree layer diversity and herb layer diversity in highly diverse subtropical forests. Apart from species richness alone, a high functional diversity of resident communities influences ecosystem functioning. Effects of functional group losses in herb layer communities of the Main Experiment were studied by species removal. Removing species or functional groups allows studying within-community (biomass) compensation and effects on the tree individuals. We applied a functional group removal experiment in the Main experiment in which most dominant functional groups (herbs, grasses, ferns and woody weeds) were experimentally removed by selective weeding. By comparing the removal subplots with control plots containing the entire suite of species, we assess the role of functional groups for herb layer feedback effects on young trees and for evaluating community responses to such a loss at the same time.
Design:
The removal experiment was established on Site A and B in June 2011 and was conducted within each 32 plots on Site A and on Site B, thus representing the full tree diversity gradient of the Main Experiment, including the tree diversity levels one (n = 16), two (n = 8), four (n = 4) eight (n = 2), 16 (n =1) and 24 (n = 1) at both sites. Within the northern four rows of each plot, five subplots (5 m × 5 m) containing each 16 trees, were established in June 2011 and randomly assigned to one of five removal treatments. Thus, the removal experiment was based on a total of 320 (2 × 32 × 5) subplots. Five levels of removal treatments were applied, i.e. woody species (W), fern species (F), grass species (G) and herbaceous species (H) were removed. One additional subplot served as a control without removal. The initial removal weeding was carried out in June 2011, where the aboveground biomass of each function group was entirely removed by selective cutting. Additional weeding took place in 2012, in June and September each, and in June 2013. The dry weight of the removed aboveground biomass was determined subsequent to the weeding campaigns. In August 2012, a vegetation monitoring was conducted for all 320 subplots. In September 2012, a subsample of each subplot was harvested for productivity assessment. In VIPs of 1- and 2-species mixtures, the total aboveground biomass was harvested within each of the removal subplots as a pooled sample of three 0.5 m × 0.5 m replicates and separated by functional group: fern, grass, woody species and herbs. In VIPs of 4-, 8- 16- and 24-species mixtures, five replicates were harvested and pooled by subplot. In September 2012 the relative light conditions and the soil moisture were measured in eaxh subplot.
Spatial extent:
Main experiment, Site A, Site B, no shrub VIPs
Temporal extent:
Initial weeding of removal treatments was performed in June 2011
Taxonomic extent:
No information available
Measurement cirumstances:
No information available
Data analysis:
For each subplot, relative light conditions, soil moisture, altitude, slope and aspect is given; for details see data group description.

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Dataset column

Name:
PTAG
Definition:
Research plots on the main experiment have a "p" in front of their IDs and then a 6 digit code: Plots in the main sites A and B are named according to their position in the original spreadsheet, in which they were designed. They consist of 6 digits: _1st digit_: Site (1:A, 2:B), _digit 2and3_: southwards row: as in spreadsheets the rows are named from the top to the bottom; _digit 4 and 5_: westward column: as in the original spreadsheet, but the letters are converted to numbers (A=01, B=02); _6th digit_: indicator, if the plot has been shifted a quarter mu. Example: "p205260": "p" means that this is a plot that is specified. "2" means, that we are at site B. Now the coordinates of the south - west corner: "0526". Since "e" is the fifth letter of the alphabet, this is Plot E26. The last digit "0" means that this plot was not moved by a quarter of a Mu, as some sites in Site A. The 6th digit can also indicate the subplot within the plot. "5", "6", "7", "8" indicate the northwest, northeast, southeast, and southwest quarter plot respectively.
Unit:
No information available
Datagroup:
BEF research plot name
Keywords:
plot, Main Experiment
Values:
p105340
p103320
p105310
p105330
p106210
Contributors:
No information available

Dataset column

Name:
Plot
Definition:
Plotnumber; Datagroup description: Plotnumber on Site A and B; 32 VIP plots with no shrub treatment;
Unit:
No information available
Datagroup:
Helper
Keywords:
VIP plots, plot
Values:
E33
C32
D29
E34
E31
Contributors:
No information available

Dataset column

Name:
treatment
Definition:
removal treatment: c= control, without removal; W= removal of woody species; F = removal of fern species; H= removal of herbaceous species; G= removal of grass species; Datagroup description: removal treatment: c= control, without removal; W= removal of woody species; F = removal of fern species; H= removal of herbaceous species; G= removal of grass species
Unit:
No information available
Datagroup:
Treatment
Keywords:
experimental treatment, removal experiment
Values:
f
c
h
g
w
Contributors:
No information available

Dataset column

Name:
tree_diversity
Definition:
tree diversity of each plot
Unit:
No information available
Datagroup:
Taxonomic biodiversity
Keywords:
diversity treatment, species diversity
Values:
4
16
2
1
24
Contributors:
No information available

Dataset column

Name:
Site
Definition:
Site on Main experiment; Datagroup description: Site A or B
Unit:
No information available
Datagroup:
Helper
Keywords:
Site A, Site B
Values:
A
B
Contributors:
No information available

Dataset column

Name:
light
Definition:
light conditions; Datagroup description: relative light conditions for each subplot in 2012-09 at 1.2 m height, mean value for each subplot; three measuring points for subplots with tree diversity level one and two; five measuring points for subplots with tree diversity level 4-24
Unit:
percent
Datagroup:
Solar radiation
Keywords:
solar radiation
Values:
0.03119257
0.039985908
0.038301593
0
0.039877482
Contributors:
No information available

Dataset column

Name:
soil_moisture
Definition:
soil moisture of each subplot in 2012-09, mean value for each subplot; three measuring points for subplots with tree diversity level one and two; five measuring points for subplots with tree diversity level 4-24; Instrumentation: Thetaprobe ML2x
Unit:
VolumePercent
Datagroup:
Soil moisture
Keywords:
soil moisture
Values:
17.34
20.2
18
19.26666667
18.98
Contributors:
No information available

Dataset column

Name:
ALTITUDE
Definition:
ALTITUDE
Unit:
No information available
Datagroup:
Elevation
Keywords:
elevation
Values:
116.363125
108.9375
116.099375
116.583125
112.299375
Contributors:
No information available

Dataset column

Name:
ASPECT
Definition:
ASPECT
Unit:
No information available
Datagroup:
Aspect
Keywords:
aspect
Values:
106.299375
103.783125
101.295
103.37375
104.500625
Contributors:
No information available

Dataset column

Name:
SLOPE
Definition:
SLOPE
Unit:
No information available
Datagroup:
Inclination
Keywords:
inclination
Values:
11.40375
12.530625
11.529375
10.293125
12.04375
Contributors:
No information available

No information available


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22 erfmeier medium

Alexandra
Erfmeier

Owner of:
23 Datasets

Involved in:
1 Projects

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73 pohl medium

Ricarda
Pohl

Owner of:
9 Datasets

Involved in:
2 Projects

E-Mail Profile
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