Main Experiment: Seed addition experiment Site A (VIPs) - biomass data

Usage Rights

This data is Free within projects.

BEF-China: SP11

Dataset Abstract

While diversity-invasibility relationships have often been addressed in experimental grassland communities, experimental approaches in forests are less common, especially in species-rich subtropical regions. Forest ecosystems feature higher complexity than grassland ecosystems, since they are composed by different vertical layers covering a high level of horizontal heterogeneity.
In the context of the Main Experiment with diversity levels from 1 to 24, we established a seed addition experiment with groups of native and exotic herbaceous species. In this early-successional forest system, seed mixtures for both groups were created with high and low functional diversity, sown into subplots along the tree diversity gradient of and harvested after one vegetation period.

Dataset Design

The seed addition experiment was established on Site A for analyzing the impact of tree diversity on herb layer invasibility and finished with harvest in October 2010. The seed addition experiment was conducted within 32 plots representing the full tree diversity gradient at Site A. These selected 32 plots included the tree diversity levels one (n = 16), two (n = 8), four (n = 4) eight (n = 2), 16 (n =1) and 24 (n = 1). Within the northern five rows of each plot, six subplots (2 m × 2 m) containing four trees, respectively, were randomly selected and established in March 2010. Thus, the seed addition was based on a total of 189 (32 × 6) subplots, each experiencing a neighbourhood tree diversity ranging from one to four (1, 2, 4). Within each subplot, seeds were added to a core area of 1 m² in the centre and surrounded by four target tree individuals, whereas the adjacent area served as a buffer zone The six subplots per plot were assigned to different seed addition treatments. Seed addition was applied by using five different seed mixtures, which were composed by six different species each. The species are annuals, bi-annuals or perennials and represent typical species of ruderal, disturbed sites like clear-cut forest areas.
Two seed mixtures were composed by native species (N) or exotic species (E) only. Within each of the groups of native and exotic species, one seed mixture was composed by functionally dissimilar species (N high and E high) and a second mixture by functionally similar species (N low and E low). A fifth seed mixture was composed by three exotic and three native species (EN) and a sixth subplot per plot received no seed addition and served as an internal control. In April 2010, each seed addition subplot received a total of 2400 seeds per m², i.e. 400 seeds per each species were sown into the subplot’s core area. Measurements of exposition and inclination were conducted in April 2010 for each subplot. Relative light conditions for each subplot were recorded in April and August 2010.

Spatial Extent

Main experiment, Site A, no shrub VIPs
29°08'-29°11'N
117°90'-117°93'E

Temporal Extent

Initial seed addition was performed in April 2010

Taxonomic Extent

The following herb species were used for seed addition:

Data Analysis

relative light conditions, inclination, exposition; for details see data group description.

Data columns available in the raw data part of this dataset

PTAG
6 digits plotnumber of main experimental site A. 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.
Data group: BEF research plot name
Keywords: VIP plots, Site A
Values
p106330
p105340
p106210
p105310
p103320
plotnumber
Plotnumber
Data group: Helper
Values
F33
C32
F21
E31
E34
treatment
seed addition treatment; Datagroup description: seed addition treatment for each subplot: C-Control with no seed addition; E-high- seed addition of six exotic species which are functionally dissimilar;E-low- seed addition of six exotic species which are functionally similar;N-high- seed addition of six native species which are functionally dissimilar;N-low- seed addition of six native species which are functionally similar;EN-seed addition of three native and three exotic species
Data group: Treatment
Keywords: experimental treatment, seed addition
Values
E_low
C
EN
N_high
E_high
treatment2
seed addition treatment; Datagroup description: category treatment: c-Control with no seed addition: n- seed addition of native species; e- seed addition of exotic species; en- seed addition of exotic and native species
Data group: Treatment
Keywords: experimental treatment, exotic species, seed addition, native species
Values
c
e
n
en
treatment3
seed addition treatment; Datagroup description: category treatment: SA- Plots with seed addition; NSA- Plots with no seed addition
Data group: Treatment
Keywords: experimental treatment, seed addition
Values
SA
NSA
tree_diversity
tree diversity
Data group: Taxonomic biodiversity
Keywords: Diversity level
Values
1
2
24
4
16
neighbourhood_tree_diversity
tree diversity; Datagroup description: neighbourhood tree diversity of the subplots; for plots with tree diversity 4-24, the neighbourhood tree diversity is 4;
Data group: Neighbourhood diverstiy
Keywords: competitive neighbourhood, diversity
Values
4
2
1
date
date; Datagroup description: mean date for each monitoring campaign, harvest started 2010-09-20 and were finished 2010-10-06
Data group: Date time information
Keywords: date
Values
2010-09-28
FD
Functional diversity
Data group: Functional biodiversity
Keywords: Rao's Q
Values
0.017856129686811068
0.007032031661428927
0.010892129003350702
0.006293027408115146
0.017580817137149474
dry_weight_exotic_total
aboveground biomass of all added exotic species at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C; Datagroup description: aboveground biomass of all added exotic species at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: dry weight, aboveground biomass, exotic species
Values
0.011
0.024
0
0.018000000000000002
0.005
dry_weight_nativ_total
aboveground biomass of all added native species at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C; Datagroup description: aboveground biomass of all added native species at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: dry weight, aboveground biomass, native species
Values
0.013000000000000001
0.027
0.005
0
0.008
dry_weight_SA_total
aboveground biomass of all added species at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C; Datagroup description: aboveground biomass of all added species at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: dry weight, aboveground biomass
Values
0
0.011
0.04
0.013000000000000001
0.03
dry_weight_other_total
aboveground biomass of the herb layer community at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C; Datagroup description: aboveground biomass of the herb layer community at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herb layer, dry weight, aboveground biomass
Values
0
0.39
1009.16
0.179
0.406
dry_weight_subplot_total
aboveground biomass of each subplot at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C; Datagroup description: aboveground biomass of each subplot at time of harvest; dry weight was determined after 48 hours in a drying oven at 72 °C
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: dry weight, aboveground biomass
Values
0.9810000000000001
1010.216
0.425
0.509
0
species_richness_total
species richness of all species
Data group: Taxonomic biodiversity
Keywords: species richness, response variable
Values
10
12
0
13
11
species_richness_exotic
species richness of exotic species; Datagroup description: number of species of added exotic species only
Data group: Taxonomic biodiversity
Keywords: species richness, response variable, exotic species
Values
1
0
3
4
2
species_richness_nativ
species richness of native species; Datagroup description: number of species of added native species only
Data group: Taxonomic biodiversity
Keywords: species richness, response variable, native species
Values
0
4
2
1
3
cover_SA
cover of added species (exotic and native) by subplot
Unit: percent
Data group: Cover of species
Keywords: vegetation cover
Values
1
12
11
10
0
cover_exotic
cover of added exotic species by subplot; Datagroup description: cover of added exotic species by subplot
Unit: percent
Data group: Cover of species
Keywords: vegetation cover, exotic species
Values
12
10
11
0
1
cover_nativ
cover of added native species by subplot; Datagroup description: cover of added native species by subplot
Unit: percent
Data group: Cover of species
Keywords: vegetation cover, native species
Values
11
12
10
1
0
cover_herb
cover of resident herbaceous species by subplot; Datagroup description: cover of resident herbaceous species by subplot
Unit: percent
Data group: Cover of species
Keywords: herb layer, vegetation cover
Values
13
10
1
100
15
cover_shrub
cover of resident woody species by subplot; Datagroup description: cover of resident woody species by subplot
Unit: percent
Data group: Cover of species
Keywords: shrub, vegetation cover
Values
10
1
100
0
15
cover_total
cover of resident community and added species each subplot; Datagroup description: cover of resident community and added species each subplot
Unit: percent
Data group: Cover of species
Keywords: vegetation cover
Values
25
15
17
100
20
herb_height
maximum height of herbaceous species by subplot
Unit: centimeter
Data group: Plant height
Keywords: herb layer, height
Values
104
103
0
10
100
shrub_height
maximum height of woody species by subplot; Datagroup description: maximum height of woody species by subplot
Unit: centimeter
Data group: Plant height
Keywords: height, shrub
Values
110
12
105
100
11
ab_ex
abundance of added exotic species
Data group: Abundance
Keywords: abundance, response variable, exotic species, seed addition
Values
101
10
100
1
0
ab_nativ
abundance of added native species; Datagroup description: abundance of added native species
Data group: Abundance
Keywords: abundance, response variable, native species, seed addition
Values
13
1
10
0
11
ab_SA
abundance of added species (exotic and native); Datagroup description: abundance of added species (exotic and native)
Data group: Abundance
Keywords: abundance, response variable, seed addition
Values
11
1
10
0
101
RGR_h
relative growth rate of the mean height of the four adjacent trees by subplot for the time period April -September 2010
Unit: centimeterPerMonth
Data group: Relative growth rate
Keywords: growth, trees
Values
0.6000000000000001
0.467
0
0.75
0.4
RGR_d
relative growth rate of the mean diameter of the four adjacent trees by subplot for the time period April -September 2010; Datagroup description: relative growth rate of the mean diameter of the four adjacent trees by subplot for the time period April -September 2010; Instrumentation: digital caliper
Unit: centimeterPerMonth
Data group: Relative growth rate
Keywords: growth, trees
Values
0.00125
0.00667
0.005
0
0.0025000000000000066