Data_Greenhouse: contains numbers of germinated seedlings of 10 species in three greenhouse
soil moisture treatments. Greenhouse conditions were: 21ºC and 16 hours light per day. Other
methods are described in Sarneel et al 2014.
Column headings
Species
species name of the ten experimental species
Alis: Alisma plantago-aquatica L.
Epi: Epilobium hirsutum
Eup: Eupatorium cannabinum L.
Fil: Filipendula ulmaria L.
Lyc: Lycopus europaeus L.
Lyth: Lythrum salicaria L.
Men: Mentha aquatica L.
Phr: Phragmites australis (Cav.) Steud.
Sag: Sagittaria sagittifolia L.
Typh: Typha angustifolia L.
Treatment
Greenhouse soil moisture treatment
DRY: 70 ml tap water (one tenth of the pot volume) was added to each pot weekly
to keep the soil moist but not wet
WL: Water logged in which the water level was maintained at field capacity which
was achieved by maintaining the water level 5 cm below soil level
FLO: The flooded treatment. Tap water was added to a depth of 5 cm above the soil.
In this treatment, the pots were covered with perforated cling-film to prevent seeds and
soil floating out of pots.
Replica
Perc_germ
Letter indicating replica. Replicates were randomized.
Germination percentage. Germinated seeds were counted and removed weekly for
8 weeks (April to June 2011). Germination percentages were calculated as the
cumulative number of seedlings over the 8 weeks as fraction of the total amount of
seeds added per pot.
Data processing steps
Germination percentages were arc sin transformed. Than they can be used for Analyses 1 (A1) as
described in Sarneel et al 2014. NA indicate data not available
Data_field: Contains numbers of germinated seedlings of 10 species in 9 nature reserves on three
elevations on the bank. Details on the method can be found in Sarneel et al 2014.
Column headings
month:
Sample month (June, July, August)
wk:
Number of weeks after the start of the experiment (8, 14, 20)
area:
Nature area. More information and a map can be found in appendix S1 belonging
to Sarneel et al., 2014.
BOH: Botshol (52º15´N4º55´E)
LOE: Loenderveen (52º12´N5º03´E)
MUY: Muyeveld (52º10´N5º05´E)
NAA: Naardermeer: (52º18´N5º06´E)
OBI: Oostelijke Binnenpolder (52º10´N5º06´E)
RON: Ronde Hoep (52º16´N4º54´E)
GRO: Groene Jonker (52º10´N4º49´E)
MID: Middelpolder (52º18´N4º53´E)
WES: Westbroekse Zodden (52º10´N5º07´E)
treatment:
Treatment of the transect,
control: mats without any seeds sown
seeds: mats in which the experimental species were sown
replicate:
Replicate number within the sample area (1-5)
pos_code:
Position code, location on the bank.
1: highest elevation on the bank
2: intermediate elevation on the bank
3: Lowest elevation on the bank
Figure: Two examples of placement of the mats on the bank.
1
1
Maximum water level
2
50 cm
50 cm
50 cm
3
2
Average water level
3
Minimum water level
flood_clas:
Code indicating the flooding regime during the measurement period.
0: The mat was not flooded during the experimental period
0.5: The mat experienced a fluctuating regime during the experimental period
1: The mat was constantly flooded during the experimental period
sampledate (M/D/Y): Date of the measurements.
time:
Time (hours) of measurements (indicative for the light measurements).
light_top:
Light intensity measured above the vegetation using Li-1925 sensor and a Li-cor®
Li-189 light meter (Lincoln, Nebraska, USA).
light_mat:
Light intensity measured directly above the mat
light_perc:
Light intensity as percentage of ambient light (light_mat/light_top*100).
fl_days:
Number of days that the water level was above mat level. Control and seed mats
were placed at the same elevation on the bank. Therefore, control and seed mats
share the same flooding characteristics. Calculations were made based on
measurements on the ‘seed’ treatment.
fl_depth
Average height of the mat above the average water level. Control and seed mats
were placed at the same elevation on the bank. Therefore, control and seed mats
share the same flooding characteristics. Calculations were made based on
measurements on the ‘seed’ treatment.
fl_freq_cum: Cumulative number of flooding events (only available for June). Control and seed
mats were placed at the same elevation on the bank. Therefore, control and seed
mats share the same flooding characteristics. Calculations were made based on
measurements on the ‘seed’ treatment.
count_tot:
Total number of seedlings per mat
count_exp:
spec_tot:
Total number of seedlings per mat from the 10 sown species
Total number of species per mat, as could be distinguished from differences in
morphology.
spec_exp:
Total number of species per mat from the 10 sown species
Alis
Total number of seedlings of Alisma plantago-aquatica L.
Epi
Total number of seedlings of Epilobium hirsutum
Eup:
Total number of seedlings of Eupatorium cannabinum L.
Fil
Total number of seedlings of Filipendula ulmaria L.
Lyc
Total number of seedlings of Lycopus europaeus L.
Lyth
Total number of seedlings of Lythrum salicaria L.
Men
Total number of seedlings of Mentha aquatica L.
Phr
Total number of seedlings of Phragmites australis (Cav.) Steud.
Sag
Total number of seedlings of Sagittaria sagittifolia L.
Typh
Total number of seedlings of Typha angustifolia L.
Epi_eup_lyth Total number of conspicuous seedlings that could either be assigned to Epi, Eup or
Lyth. In the analyses of the manuscript those were classified to Lythrum in a
variable Lyth_plus.
Remark
Remarks on condition of the mat: how well the soil was retained in the mat,
whether there was vegetation invading the mat. In some cases, the regrowth of
vegetation from underneath the plot pushed the mats a bit aside. This is indicated
with ‘slightly moved’.
Data processing steps
Dataset 1:
Belonging to: Analyses 2 (A2), script 1 in appendix S4 of Sarneel et al 2014:
Numbers of seedlings per species as counted in June (wk. 8) were used. All other data was not
taken into account. Column Epi_Eup_Lyth was considered to belong to Lyth and therefore the
sum of those two columns was analysed.
When two or three mats of one replicate belonged to one flooding category, the values for those
two or three were averaged to prevent pseudo replication. Per replicate we therefore only
incorporated one value per flooding category.
Dataset 2:
Analyses 3, script 2 in appendix S4 of Sarneel et al 2014:
count_tot, count_exp, spec_tot, spec_exp were averaged per flooding category per area per
month.
To calculate Shannon values per mat, we used the R package vegan. Calculations were based on
the experimental species. Epi_Eup_Lyth was considered to be Lyth.
Weighted Ellenberg values per mat were calculated as
(Typh+Alis+Sag+Phr)*10+(Lyc+Men)*9 + (Epi+Lysa_plus+div$Fil)*8 + Eup*7)/count_exp)
Values were first calculated per mat and afterwards averaged to obtain one value for each
flooding category per area per month.
Dataset 3:
Analysis 4, script 3 in appendix S4 of Sarneel et al 2014.
All data entries from June were used. No additional processing.
Dataset 4:
Analyses 5, script 4 in appendix S4 of Sarneel et al 2014.
The Shannon and Ellenberg values were calculated as for dataset 2. All measurements from June
were used.
Data processing for analyses 6.
1. Seedling numbers per transect were calculated by summing the high, middle and low
mats. Data used was the seed treatment in June (n = 45 transects).
2. Number of seed bank species was calculated by determining the number of experimental
species present on at least one of the mats of each replicate transect (high, middle or low)
3. Shannon diversity and Ellenberg values per transect were calculated as in dataset 2, using
the summed number of seedlings within each replicate transect. Epi_Eup_Lyth was
considered to be Lyth.