CSPs: Kinetic energy of raindrops below target trees in the CSPs

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: Geißler, C., Scholten, T. and Kühn, P. (2010): Measurements of kinetic energy under target trees in the CSPs. BEF-China data portal (Accessed through URL http://china.befdata.biow.uni-leipzig.de/datasets/170)

Dataset Abstract

Sand-filled splash cups were used to study the erosivity of rainfall and throughfall in the humid subtropics of southeast China. Our results showed that the splash cup measurements yielded precise and reproducible results both under open field conditions and under forest vegetation. The splash cups were exposed to forest stands of different age and to selected species in the Gutianshan National Nature Reserve (GNNR). This dataset contains the measurements performed under selected trees.

Dataset Design

Species specific measurements: Sets of five splash cups were positioned in a pentagon under target trees.
The splash cups consist of a PE flask to which a carrier system has been attached. In this carrier system a cup filled with a unit sand of 125-200 µm particle size is inserted. At the bottom of the cup a silk cover prevents loss of sand and guarantees free drainage of water from the cup to the carrier and vice versa. Cup and PE flask are hydraulically connected by a cotton wick to ensure constant moisture content throughout the time of measuring, as the initial water content is a crucial point in splash erosion studies (Poesen and Savat 1981). Additionally, vents in the carrier system ensure that the pressure arising from the insertion of the cup does not lead to loss of sand. The vent in the PE flask guarantees the free drainage of excess water which may accumulate during high intensity rainfall events.

Spatial Extent

The Gutianshan National Nature Reserve (NNR) is located in the western part of Zhejiang Province (29º8'18" – 29º17'29" N, 118º2'14" – 118º11'12" E, Fig. 1). The Gutianshan NNR has an area of approximately 81 km2 and was initially established as a National Forest Reserve in 1975 and became a National Nature Reserve in 2001. The NNR comprises a large portion of broad-leaved forests of advanced successional stages (Hu & Yu 2008), which have not been managed since the beginning of the 1990ies, as well as young successional stages and conifer plantations, mainly of Cunninghamia lanceolata and Pinus massoniana. --- The vegetation is composed of different types of subtropical evergreen and mixed broad-leaved forests (Yu et al. 2001). Most of the stands are secondary forests, evidenced by maximum tree ages of 180 years, by agricultural terraces in almost all plots and by the presence of charcoal in almost all soil profiles. Around the Gutianshan NRR extensive deforestation has occurred during the Great Leap Forward in the 1950s, as in most parts of Southeast China. However, due to prevailing steep slopes, the Gutianshan area was only marginally usable for agricultural activities, and thus an exceptionally intact forest cover has been preserved. --- The climate at Gutianshan NNR is warm and temperate with a short dry season in November and December and with warm summers (Fig. 2). The climatic conditions are characteristic for the subtropics with an annual average temperature of 15.1°C, January minimum temperatures of -6.8°C, July maximum temperatures of 38.1°C and an accumulated temperature sum (≥ 5°C) of 5221.5 degree days.

Published

partly in "CATENA" (2012) and "Journal of Earth Sciences" (2010), method description in "Journal of Plant nutrition and Soil Science" (2012)

Taxonomic Extent

Tree species names are given in the raw data

Data Analysis

Rain event characteristics come from a linked dataset: "Rainfall for rain events within splashcups measurements for kinetic energy of raindrops".

Data columns available in the raw data part of this dataset

campaign
sequential number of the measring campaign
Data group: Helper
Values
1
3
2
event_no
Sequential number of the measured rainfall events
Data group: Rainevent for determinig kinetic energy of rainfalls
Keywords: precipitation
Values
1
11
12
10
13
CSP
name of the CSP in the Nature ReserveBEF research plot nameReasearch plots of the Biodiversity - Ecosystem functioning experiment (BEF-China). There are three main sites for research plots in the BEF Experiment: Comparative Study Plots (CSP) in the Gutianshan Nature Reserve, having a size of 30x30m^2, measured on the ground.
Data group: BEF research plot name
Keywords: CSP
Values
CSP04
CSP03
CSP05
CSP08
CSP02
age_class_3
Age class of the CSP (3 classes), copied from the CSP successional stages data set
Data group: Helper
Keywords: succession
Values
5
1
4
3
age_class_5
Age class of the CSP (5 classes), copied from the CSP successional stages data set
Data group: Helper
Values
3
2
1
5
4
rarefy_100
rarefied species richness, copied from the CSP diversity dataset
Data group: Taxonomic biodiversity
Keywords: biodiversity
Values
19.83457198
19.18847034
20.18729069
19.92291558
16.77861972
shannon
shannon diversity of CSP trees, copied from the CSP diversity dataset
Data group: Taxonomic biodiversity
Values
2.33790930497816
2.63189534329409
2.55435250698063
2.59877974008667
2.51963828654328
simpson
simpson diversity of CSP trees, copied from the CSP diversity dataset
Data group: Taxonomic biodiversity
Values
0.88173806480979
0.855971684531093
0.897252720321537
0.890895936894677
0.86276924203689
event_start
start date of the event
Data group: Date time information
Keywords: date
Values
2008-09-10
2008-09-03
2008-08-24
2008-08-30
2008-08-27
event_end
end date of the event
Data group: Date time information
Values
2008-08-26
2008-09-05
2008-09-11
2008-08-28
2008-08-31
event_mm_bo
rainfall amount as measured by the rainfall collecting bottle; copied from the rainfall event overview
Unit: millimeter
Data group: Helper
Keywords: precipitation
Values
2.36
103.13
21.11
20.96
111.14
event_mm_va
rainfall amount as measured by the Vaisala sensor; copied from the rainfall event overview
Unit: millimeter
Data group: Helper
Values
11.61
1.8
33.95
3.8
26.15
event_mm_tb
rainfall amount as measured by the tipping bucket rain gauge; copied from the rainfall event overview
Unit: millimeter
Data group: Helper
Values
83.7
39.9
2.8
22.3
70
tree_species
Species name of the measured tree individual
Data group: Scientific plant species name
Keywords: species
Values
Castanopsis eyrei
Castanopsis fargesii
Cyclobalanopsis glauca
Cunninghamia lanceolata
Castanopsis tibetana
tree_number
Tag number of the tree under which the splashcups were positioned. Consists of 6 digit coding according to the identification and allocation of species as referenced in the dataset 238 ("Tree stem reference list for the Comparative Study Sites (CSPs)"). In the case of tree(s) with additional letters in this cloumn, this refers to individuals mith multiple stems. The letters are used to distinguish between the multiple stems.
Data group: CSP metal tag number (trees, woody debris)
Keywords: tree
Values
363799
363080
111111
363046
363640
position_scs
position_scs
Data group: Splashcup position
Keywords: splashcup
Values
101
1
103
100
102
tree_height_m
Tree height (SP1), copied from the SP1 file on tree size
Unit: millimeter
Data group: Helper
Keywords: size
Values
11
10.7
10
10.2
10.8
thoughfall_mm
Throughfall as measured by the throughfall collecting bottles
Unit: millimeter
Data group: Precipitation
Keywords: precipitation
Values
101.80505415162456
101.08303249097473
103.24909747292419
10.108303249097473
100.36101083032491
loss_sand_g
loss of sand from splash cups during the event
Unit: gram
Data group: Deriving kinetic energy from sand loss
Keywords: kinetic energy, raindrop
Values
0.12999999999999545
0
0.05999999999998806
0.15000000000000568
0.12000000000000455
loss_sand_g_m2
loss of sand from splash cups during the event extrapolated to m²
Unit: gramPerSquaremeter
Data group: Deriving kinetic energy from sand loss
Values
0.9627517370147152
0.7220638027610791
0.9025797534513488
0.7822357863244453
0.36103190138045405
KE_area
loss of sand from splash cups during the event extrapolated to m² and converted into KE
Unit: joule per squaremeter
Data group: Deriving kinetic energy from sand loss
Keywords: kinetic energy, raindrop
Values
1004.2012079325001
1001.5747008098547
1005.9522125505
1004.2012078923968
1000.6991984055