Pilot experiment: tree - herb interactions and invasibility of exotic species

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: Erfmeier, A. and Both, S. (2013): Tree - herb interactions and invasibility of exotic species. BEF-China data portal (Accessed through URL http://china.befdata.biow.uni-leipzig.de/datasets/429)

Dataset Abstract

Exotic species are assumed to alter ecosystem functioning. However, little is known of the relationships within vertically structured plant communities such as forests, where tree saplings interact with herbaceous species, especially in the early phases of succession. This relationship was tested in a common garden experiment which assessed the impacts on tree saplings and herbaceous species following nutrient addition and the introduction of exotic herb species. We studied the relationships between tree sapling diversity, herb-layer productivity and invasibility in an early-successional forest ecosystem. A full factorial design was applied, within which species com- position was crossed with nutrient and exotic seed-addition treatments. The seed-addition treatment included mixtures of seeds from eight exotic herb species, and herb community attributes were assessed after a four month growing season.

Dataset Design

We applied fertilizer and exotic seed-addition treatments in a factorial design to randomly chosen plots. Eight exotic herbaceous species, selected according to their abundance in the Jiangxi and nearby Zhejiang provinces (seeds collected in 2008), were used for the seed-addition. Each exotic species was represented by 150 seeds per seed mixture applied to each plot. Fertilizer was applied shortly before seed-addition and plots received 13 g·N·m2·yr–1 added as NPK (17-13-15) standard fertilizer. At the end of May 2009, after weeding of the plots, the seed mixtures were sown into the bare ground at the centre of each plot (0.6 m × 0.6 m) along with four tree saplings, representing the respective tree diversity level. The remaining plot area acted as a buffer zone with the same treatment combination (tree diversity × fertilizer) but without seed-addition. At the end of September 2009, the total number of individuals (abundance) and the number of reproducing individuals of each herb species were counted. The height of each species was assessed by averaging the height of five randomly selected individuals. These values were used to calculate the abundance-weighted mean height of the herb-layer. In addition, herb-layer aboveground biomass was determined by harvesting each species separately. The harvested plant material was oven-dried (70°C 48 h) and weighed.

Spatial Extent

Pilot Experiment, Xingangshan, Jiangxi Province, China
29°06'N
117°55'E

Published

Both S, Fang T, Baruffol M, Schmid B, Bruelheide H, Erfmeier A (2012). Effects of tree sapling diversity and nutrient addition on herb-layer invasibility in communities of subtropical species. Open Journal of Ecology 2(1). http://www.scirp.org/journal/Pap

Temporal Extent

Final harvest of the SP11 Pilot experimental plots was conducted in September 2009

Taxonomic Extent

Exotic herbaceous species were Ageratum conyzoides, Amaranthus spinosus, Chenopodium ambrosioides, Crassocephalum crepidioides, Oenothera biennis, Phytolacca americana, Sesbania cannabina and Solidago canadensis. Tree species used: Elaeocarpus decipiens, Schima superba, Quercus serrata, Castanea henryi

Data Analysis

The variables of interest were invasibility measures like cover and abundance (cover, abundance) of introduced exotic species. In addition, fitness variables like number of flowering or fruiting individuals (ind_with_flow, ind_with_fruits) verify the success of the exotic species and the resident native species. On the community level the productivity of the herb-layer can be assessed by summing up biomass of each species (total_BM) and then can be analysed as a function of the treatments applied (seed_add, fert).

Data columns available in the raw data part of this dataset

date
date
Data group: Date time information
Keywords: date
Values
2009-09-19
2009-09-23
2009-09-21
2009-09-22
2009-09-20
block
block within pilot experiment
Data group: Block code in the pilot experiment
Keywords: Pilot experiment, location, block
Values
1
4
2
3
plot_old
plot identification within pilot experiment
Data group: Helper
Keywords: Pilot experiment, location, plot
Values
AF10
AF11
AF1
AF2
AF12
plot_id
The community code combines the block number (numbers with _), plot tree community (as numbers) and the plot allocation to a subgroup (as letters)
Data group: BEF research plot name
Keywords: Pilot experiment, location, plot
Values
2_AF12
4_AF12
pilot1AF02
pilot1AF01
pilot1AF03
tree_diversity
tree diversity of the plot
Data group: Taxonomic biodiversity
Keywords: Diversity level
Values
2
4
1
0
tree_species
tree species present in the plot
Data group: Community Composition
Keywords: Composition
Values
Castanea
0
Castanea_Quercus
Castanea_Elaeocarpus_Quercus_Schima
Elaeocarpus
seed_add
seed addition treatment; s= seeds added; ns= no seeds added
Data group: Treatment in the Pilot Experiment
Keywords: experimental treatment, seed addition
Values
s
ns
fert
fertilizer application treatment, f= fertilized; nf= non-fertilized
Data group: Treatment in the Pilot Experiment
Keywords: experimental treatment, fertilizer
Values
f
nf
species
species monitored in the herb-layer
Data group: Scientific plant species name
Keywords: herbs, species
Values
Acalypha australis
Ageratum conyzoides
Alternthera philoxeroides
Amaranthus spinosus
Alternthera sessilis
* Eichenberg, D. also contributed to this column.
species_approx
where exact determination was not possible. approximate species name are given here as information
Data group: Helper
Keywords: herbs, species
Values
Alternthera sessilis
Ageratum conyzoides
Acalypha australis
Amaranthus spinosus
Alternthera philoxeroides
* Eichenberg, D. also contributed to this column.
status_species
status of the species monitored in the herb-layer, e= exotic, n= native
Data group: Species status (native, exotic)
Keywords: exotic species, native species
Values
e
n
cover
cover of the species monitored in the herb layer
Unit: percent
Data group: Cover of species
Keywords: herbs, vegetation cover
Values
1
15
0
12
10
abundance
abundance of the species monitored in the herb layer
Data group: Abundance
Keywords: herbs, abundance
Values
10
12
11
1
0
ind_with_flow
number of individuals of the respective species showing flowers
Data group: Reproductive organs
Keywords: reproductive organs, flowers
Values
12
10
1
11
0
ind_with_fruits
number of individuals of the respective species showing fruits
Data group: Reproductive organs
Keywords: reproductive organs, fruits
Values
0
14
11
1
10
ind_with_flowfruit
number of individuals of the respective species showing flowers and fruits
Data group: Reproductive organs
Keywords: reproductive organs, flowers, fruits
Values
1
11
12
10
0
ind_without_repr_org
number of individuals of the respective species showing no reproductive organs
Data group: Reproductive organs
Keywords: reproductive organs, flowers, fruits
Values
0
10
1
11
12
average_height
average height of the respective species
Unit: centimeter
Data group: Plant height
Keywords: species, height
Values
105
10
110
11
100
max_height
maximal height of the respective species
Unit: centimeter
Data group: Plant height
Keywords: species, height
Values
101
103
10
100
102
plot_block
unique identification of plot within block
Data group: Pilot Experiment: Plot ID
Keywords: plot
Values
AF10_4
AF1_1
AF10_1
AF10_2
AF10_3
total_BM
total aboveground biomass of all individuals of the respective species
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herbs, aboveground biomass
Values
0.004
0.001
0.008
0.01
0.011
shoot_BM
biomass of shoots of all individuals of the respective species
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herbs, aboveground biomass, shoot
Values
0.004
0.01
0.002
0.005
0.001
leaves_BM
biomass of leaves of all individuals of the respective species
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herbs, leaf, aboveground biomass
Values
0.005
0.001
0.002
0.006
0.004
repr_org_BM
biomass of reproductive organs of all individuals of the respective species
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herbs, aboveground biomass, reproductive organs
Values
0.01
0.02
0.005
0.001
0.002
fruit_BM
biomass of fruits of all individuals of the respective species
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herbs, aboveground biomass, fruits
Values
0.002
0.01
0.06
0.08
0.04
flow_BM
biomass of flowers of all individuals of the respective species
Unit: gram
Data group: Above and below ground biomass measurement
Keywords: herbs, aboveground biomass, flowers
Values
0.01
0.003
0.05
0.02
0.001