SPAC system is a comprehensive platform for observation of plant transpiration water consumption and environmental factors. In this project, a set of SPAC system is set up in the Alxa Desert eco hydrological experimental study. The main observation data include temperature, relative humidity, precipitation, photosynthetic effective radiation, etc. the sampling frequency is one hour. This data provides basic data support for the study of plant transpiration water environmental response mechanism.
2020-03-06
The dataset investigated the growth status of plants and leaf morphological indexes of single and conjoined red sand and pearl in the middle and lower reaches of heihe river basin in 2013. The growth indexes were crown width, plant height, and biomass of fine roots and thick roots.Leaf shape indicators are: length, width, thickness, and leaf area, volume, etc.The experimental observation indexes are: leaf nitrogen content, water potential, gas exchange data, chlorophyll fluorescence data. Data include: field observation data and explanatory documents.
2020-03-05
The data set contains the data of thermal diffusion fluid flow meter in the hydrometeorological observation network from January 1 to December 31, 2015. The study area is located in huyang forest, ejin banner, alxa league, lower reaches of heihe, Inner Mongolia autonomous region.According to the different height and diameter at breast height of iminqak, choose install Thermal diffusion flow meter sample tree (Thermal Dissipation SAP flow velocity Probe, TDP), domestic TDP pin type Thermal diffusion plant flow meter, model for TDP30.The TDP1 point and TDP2 point of sample plots were set in the vicinity of mixed forest station and populus populus station, respectively.Sample tree height from high to low in turn for TDP2 (16.4 meters, 18.3 meters, 16.9 meters), TDP1 (12.5 meters, 13 meters, 14 meters), diameter at breast height order from large to small is TDP1 (48 cm, 41.6 cm, 46.6 cm), TDP2 (33.8 cm, 38.5 cm, 42.3 cm), density of TDP1 respectively (0.0158 per square meter) tree, TDP2 (0.0116 per square meter), to represent the whole area of populus euphratica transpiration measurement.Two sets of probes are installed in each sample tree, with a height of 1.3 meters and a direction of east and west of the sample tree. The original observation data of TDP is the temperature difference between the probes, and the collection frequency is 10s, with an average output of 10 minutes.The published data are calculated and processed trunk flow data, including flow rate V (cm/h), flux Fs (cm3/h) and daily transpiration Q (mm/d) per 10 minutes.Firstly, the liquid flow rate and liquid flux were calculated according to the temperature difference between the probes, and then the transpiration Q per unit area of the forest zone was calculated according to the area of Euphrates poplar forest and the distance between trees at the observation points.At the same time, post-processing was carried out on the calculated rate and flux value :(1) data that obviously exceeded the physical significance or the instrument range were removed;(2) the missing data is marked with -6999;(3) suspicious data caused by probe fault or other reasons shall be identified in red, and the data confirmed to have problems shall be removed. Please refer to Li et al. (2013) for hydrometeorological network or site information, and Qiao et al. (2015) for observation data processing.
2020-03-05
In the middle of July and August 2012, mass photosynthesis was determined and the plant species was caragana korshinskii. The mass photosynthesis measurement system is composed of li-8100 closed-circuit automatic soil carbon flux measurement system (li-cor, USA) and an assimilation box designed and manufactured by Beijing liaotai technology co., LTD. Li-8100 is an instrument for soil carbon flux measurement produced by li-cor, USA, which USES an infrared gas analyzer to measure CO2 and H2O concentrations.The length, width and height of the assimilation box are all 50cm.The assimilation box is controlled by li-8100, and the instrument can operate automatically after the measurement parameters are set. The photosynthetic rate of population was calculated according to the following formula: CAP (Canopy growth Rate) is the Photosynthetic Rate of the population (mol CO2•m -- 2•s -- 1).A is the total leaf area (m2) of the plant canopy;VA is the total volume (m3) of the population photosynthesis measurement system, which is the product of the height of the assimilation box from the ground (the distance between the upper edge and the inner ground after the special base is placed), the soil area (0.25 m2) and the sum of the volume of the assimilation box (0.125 m3).Is the change rate of CO2 measured by assimilation chamber (mol CO2•mol -- 1•s -- 1) in the process of population photosynthesis measurement;Is the CO2 change rate (mol CO2•mol -- 1•s -- 1) measured in a 20 cm measuring chamber during the soil respiration measurement process;P is atmospheric pressure (Pa), T is the air temperature in the assimilation chamber (℃), and R is the gas constant (8.314 Pa•m3•mol-1• k-1).N is the conversion coefficient, which means the change rate of CO2 caused by soil respiration in the soil area (SA) covered by the assimilation box and in the total volume (VA) of the population photosynthesis measurement system is converted from the measurement in the 20cm measurement chamber, and calculated according to the following formula: SA is assimilation box cover soil area, 0.25 m2, SC is 20 cm soil area of the measuring chamber cover (0.03 m2), VC is plant roots and soil respiration measurement system of the total volume (m3), to 20 cm measurement chamber high from the ground (after ring on measuring the soil in place along with the internal distance) on the ground and soil area is the product of the (SC) and 20 cm measurement chamber volume (4.82 x 10-3 m3) combined.
2020-03-04
This data set is collected according to the output results of tesim ecological process model, including biomass, plant N and P content, evapotranspiration, NPP and other model output results. Some of the results are obtained by field measurement, some by laboratory analysis of field samples, some by literature.
2020-03-02
In the late June and early July of 2014, the dominant species of desert plants in the lower reaches of Heihe River, Lycium barbarum and Sophora alopecuroides, were selected. Using the LI-6400 portable photosynthesis system (LI-COR, USA), the photosynthetic and water physiological characteristics of desert plants were measured and analyzed.
2020-01-10
This data is based on the observation of corn in the middle reaches of heihe river irrigated area. The observation instrument is licor-6400 XTR and the site is selected near the HiWATER combined test superstation.The photosynthesis parameters of maize were observed through uncontrolled experiments and controlled experiments (controlling carbon dioxide and light intensity) from June 22, 2012 to August 24, 2012.
2019-12-27
The accurate estimation of sapwood area and heartwood area is the main means to convert the transpiration water consumption scale. In October 2011, this project investigated the sapwood and heartwood of 98 Populus euphratica in Ejin Oasis and measured the width of sapwood and heartwood. The relation curve of sapwood area with DBH and height was established. Please refer to LI Wei, SI Jianhua,FENG Qi, YU Teng fei. Response of Transpiration to Water Vapour Pressure Defferential of Populus euphratica. Journal of Desert Research, 2013, 33(5): 1377-1384. for details.
2019-09-15
In mid July 2011, the photosynthetic organs (leaf or assimilating branches) of typical desert plants were collected and determined by laboratory. The indicators include: leaf water potential, total leaf water content, relative water content, dry weight water content, leaf dry matter content, specific leaf area, specific leaf volume, free water, bound water, etc.
2019-09-15
Spectral reflectance observation was carried out for the typical underlying surface and black and white cloth in the low reaches of the Heihe River Basin during the aviation flight experiment in 2014, which will provide basic data set for the preprocessing of the flight data. 1. Observation Instrument PRS-3500 portable spectrometer, with the spectral range is 350-2500 nm, and the reference board. 2. Samples and observation methods The samples including the black and white cloth, the cantaloupe, the Tamarix chinensis, the Populus euphratica, the reeds, the weeds, the Karelinia caspica, the sandy soil, the gobi, the Sophora alopecuroides and so on. Reflectance of the reference board was measure vertically for once and then objective reflectance were measured for five times for each observation objective. 3. Observation time The typical underlying surface vegetation observation was on days of 24 July, 27 July, 31 July, 2014. The black and white cloth simultaneous observation was on 29 July, 2014. 4. Data storage The observation recorded data were stored in excel and the original spectral data were stored in *.sed files derived from the spectrometer, which can be opened by the matched software of the spectrometer or by a txt.
2019-09-15
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