Data set of soil physicochemical in Qinghai-Tibet Plateau (2019-2021)

The data set contains soil physicochemical properties of ten scientific expedition routes in Qinghai-Tibet Plateu during 2019-2021, including sample colletor, sampling time, sampling location, longitude and latitude, altitude, vegetation type, sampling depth, soil water content, pH, organic matter content, total carbon content, total nitrogen content, total phosphorus content, inorganic nitrogen content, heavy metal elements content, and etc. The physicochemical properties were measured in the laboratory with quality control, including measuring blanks, replicates and standard samples.The data set can be used for evaluating soil quality and function under the influence of climate change and human activities.

0 2022-04-18

Comprehensive observation for carbon dioxide isotopes during soil biochemistry process: synergetic profile observation system of the CO2 and δ13C gradients in the soil and atmosphere (2019-2020)

Soil respiration is the second most important carbon flux, which is only lower than that of photosynthesis in terrestrial ecosystems. The production and transport of CO2 and its δ13C by soil biochemical processes are the limiting factors for the magnitude and process evaluation of soil respiration. According to the characteristics of CO2 gas generation and transportation in soil biochemical process, based on stable isotope infrared spectroscopy technology, the nonlinear on-line calibration technology, multi-channel double-cycle efficient gas circulation path, efficient gas circulation path with pre-reduced gas concentration, and variable temperature technology that can simulate the freezing and thawing process were independently developed. On account of the gas exchange process in soil and air interface, vertical migration process of CO2 in soil profile and the process of soil organic matter decomposition, we develop a comprehensive observation system for measuring the isotope composition of carbon dioxide during soil biochemistry processes. The observation systems were placed in the ecologically fragile areas and measured the concentration and flux of soil CO2 and its δ13C, which effectively solved the comprehensive monitoring problem in generation, migration and release of CO2 during soil biochemical process. A synergetic profile observation system of the CO2 and δ13C gradients in the soil and atmosphere: We develop key gas circuit components for the prereduction of CO2 and δ13C concentrations that are suitable for field and laboratory experiments. For the problems of large variations in greenhouse gas concentrations between the atmosphere and soil and the high greenhouse gas concentration in soil, we use a typical CO2 absorbent or the zero gas in the bypass system to decrease the CO2 concentration in the gas circuit. Meanwhile, the instrument can eliminate the disturbance of “dead gas” on the observation results and improve the accuracy of the observations. From the technical innovation, the on-line calibration system of both low concentration and high concentration was realized for the first time, which solved the nonlinear response and time drift of the instrument, the gas path design of multi-channel double circulation and the gas path design of CO2 concentration pre-reduction, and effectively solved the problem of low gas path switching efficiency caused by pipeline length. The average domestication rate of the equipments is more than 80%, which has been used in the automatic monitoring of forest, grassland and farmland ecosystems, realizing the independent innovation and upgrading of ecological monitoring technology in China, and can be extended to CERN, CFERN, CNERN and similar field stations in other related departments. It is helpful to greatly improve China's R&D capability, level and international influence on ecological monitoring and assessment, effectively support China's terrestrial ecosystem carbon sequestration rate and potential assessment and certification, and provide technical support for national ecological civilization construction, carbon peak, carbon neutrality and ecological security regulation.

0 2021-11-29

Data set of comprehensive observation system for carbon dioxide isotopes during soil biochemistry process: multichannel measurement system for soil microbial CO2 and δ13C fluxes that can automatically control and change the temperature (2019-2020)

Soil respiration is the second most important carbon flux, which is only lower than that of photosynthesis in terrestrial ecosystems. The production and transport of CO2 and its δ13C by soil biochemical processes are the limiting factors for the magnitude and process evaluation of soil respiration. According to the characteristics of CO2 gas generation and transportation in soil biochemical process, based on stable isotope infrared spectroscopy technology, the nonlinear on-line calibration technology, multi-channel double-cycle efficient gas circulation path, efficient gas circulation path with pre-reduced gas concentration, and variable temperature technology that can simulate the freezing and thawing process were independently developed. On account of the gas exchange process in soil and air interface, vertical migration process of CO2 in soil profile and the process of soil organic matter decomposition, we develop a comprehensive observation system for measuring the isotope composition of carbon dioxide during soil biochemistry processes. The observation systems were placed in the ecologically fragile areas and measured the concentration and flux of soil CO2 and its δ13C, which effectively solved the comprehensive monitoring problem in generation, migration and release of CO2 during soil biochemical process. This research developed a multichannel measurement system for soil microbial CO2 and δ13C fluxes that can automatically control and change the temperature. We develop a fully automatic temperature control and measurement system that can simulate the freeze-thaw process. The instrument can adjust the temperature in a culture flask under established procedures and meet the experimental requirements of simulating complex processes during the decomposition of soil organic matter. The temperature control range of the system is -5~35 oC, the temperature control accuracy is better than 0.23 oC, the temperature change rate is 1.06 oC /2 min (0~35 oC) and 0.70 oC /2 min (-5~0 oC), at least 16 channels of culture flask and 3 channels of gas can be controlled simultaneously, which achieve (or better) than the core technical indicators of the project requirements. Soil samples collected in the field were placed in 16 sample bottles, respectively. Based on the multichannel measurement system for soil microbial CO2 and δ13C fluxes, the soil respired CO2 and δ13C data were obtained during the warming and cooling processes from -5℃ to 35℃. Data processing usually begins from the instrument performance parameters for judging data quality first, then the measured CO2 concentration and δ13C were corrected with standard gas. The slope of air humidity, temperature, atmospheric pressure and flux calculation was quality-controlled to eliminate abnormal data. Then the high quality data was obtained and the flux is used to calculate the formula to calculate the CO2 and δ13C flux. The average domestication rate of the equipments is more than 80%, which has been used in the automatic monitoring of forest, grassland and farmland ecosystems, realizing the independent innovation and upgrading of ecological monitoring technology in China, and can be extended to CERN, CFERN, CNERN and similar field stations in other related departments. It is helpful to greatly improve China's R&D capability, level and international influence on ecological monitoring and assessment, effectively support China's terrestrial ecosystem carbon sequestration rate and potential assessment and certification, and provide technical support for national ecological civilization construction, carbon peak, carbon neutrality and ecological security regulation.

0 2021-11-17

Soil properties data set of different land use types along the Qinghai-Tibet Highway (2019)

From July to August 2019, 147 soil samples of different land use types were collected every 20km,in sections from Xining City to Golmud of Qinghai Province, from Golmud of Qinghai Province to Lhasa of Tibet Autonomous Region, and from Golmud to Xining, far away from human disturbance. Totally, 147 soil samples were collected, including 83 grassland, 48 sandy land, 14 agricultural land and 3 forest land. The data set includes serial number, geographical location of sampling points, land use type, longitude and latitude coordinates, altitude, soil total nitrogen, total phosphorus, total potassium content and soil pH. The data format is Excel table. This data set is obtained by the combination of field sampling and indoor experiments. Soil samples in 0-15 cm layer was collected with a soil drill (8 cm in diameter) in each square by random sampling method, and the soil separated from the root system was screened by using a coarse screen. The total nitrogen, total phosphorus and total potassium was measured from the whole sample, and the 0.15 mm soil sample was used, in which the total nitrogen was measured by semi-automatic Kjeldahl nitrogen determinator, the total phosphorus was measured by spectrophotometer, and the total potassium was measured by flame photometer. The measurement of soil PH value was as: weighed 10g of air dried soil sample screened by 1mm into a 50ml beaker, added carbon dioxide free distilled water to maintain the water-soil ratio of 2.5:1, and measured it in PHSJ-4F laboratory. This data can provide data support and scientific basis for alpine ecosystem restoration.

0 2021-10-28

Data of soil properties in sanjiangyuan region, Qianghai -Tibetan Plateau (2020)

From September to October 2019, a field survey was carried out along the 214 National Highway in the Sanjiangyuan District to investigate the geology, landform, climate and vegetation type data, and to collect soil samples along the line, a total of 32 soil samples. Field surveys were carried out in the typical desertified grassland, grazing grassland and plateau pika activity areas in the source area of the Three Rivers from June to July 2020, including 15 soil samples with different degrees of desertification, 9 soil samples with different grazing intensity, and pika activity areas There are 12 soil samples, 36 in total. The two field surveys totaled 68 soil samples. The content of the data set includes serial number, geographic location of each sample point, land use type, latitude and longitude coordinates, altitude, soil total nitrogen, total phosphorus, total potassium content and soil pH. The data format is an Excel table. This data set is obtained by self-determination by combining field sampling and indoor experiment. The total nitrogen is measured by a semi-automatic Kjeldahl nitrogen analyzer, the total phosphorus is measured by a spectrophotometer, the total potassium is measured by a flame photometer, and the pH is measured by a PHSJ-4F laboratory pH meter. This data can provide data support and scientific basis for the restoration of the alpine ecosystem.

0 2021-10-11

Lalu wetland soil monitoring data set (2019)

Tibet Lalu Wetland National Nature Reserve, with a total area of 6.2 square kilometers and an average altitude of 3645 meters, is a typical wetland on the Qinghai Tibet Plateau, belonging to reed peat swamp. The data set includes the following soil physical and chemical properties: soil pH value, soil moisture content, soil organic carbon, soil total phosphorus content, available phosphorus content, soil total potassium content, soil available potassium content, soil total nitrogen content, soil ammonium nitrogen and soil nitrate nitrogen; The data can be used in related scientific research such as soil quality evaluation of Lalu wetland.

0 2021-06-15

Data set of surface dust properties in the middle and upper reaches of the Yarlung Zangbo River

The data set contains the magnetism, grain size, geochemical element, chromaticity and organic carbon isotope data of 119 topsoils in the middle and upper reaches of the Yarlung Zangbo River, southern Tibetan Plateau; contains the age, magnetism, grain size, geochemical element, chromaticity and organic carbon isotope data of the five aeolian sedimentary sections in this region; and contains chronological data of 36 aeolian sediments, provenance data of 46 samples from different sediments, and Sr-Nd isotopic data of 21 samples from different sediments. The magnetic susceptibility was measured using a Bartington MS2 metre with a dual-frequency sensor; The anhysteretic remanent magnetization was induced by LDA-5 demagnetizer, and was measured using a JR-6A Minispin magnetometer; The grain size was measured by Malvern Mastersizer 2000 laser particle size analyzer; The geochemical element was determined by X-ray fluorescence spectrometer; The chromaticity was measured by CM-700d spectrophotometer; The organic carbon isotope was determined by element analyzer-stable isotope ratio mass spectrometer (EA-IRMS); Optically stimulated luminescence measurements were conducted using an automated Risø-TL/OSL-DA-20 reader; For the AMS14C and Sr-Nd isotope measurements, please refer to the main body of the scientific research report. The data set is rich in information, authentic and reliable, and provides an important data reference for understanding the physical and chemical properties of surface dust, provenance, and the long-term evolution history of ancient dust in Yarlung Zangbo River basin, southern Tibetan Plateau. Funded project: The Second Tibetan Plateau Scientific Expedition Program (STEP), Task 6 Topic 2 "Dust aerosol and its climatic and environmental effects" (2019QZKK0602).

0 2021-05-29

Survey data set of plant and soil carbon and nitrogen cycle in representative sites (2019-2020)

The data set includes three types of data, which are: (1) the data of soil physical and chemical indexes, carbon and nitrogen, plant carbon and nitrogen, and microbial carbon and nitrogen in the collapse area of the Qinghai Tibet Plateau in 2020. These data provide an important reference for the assessment of the carbon and nitrogen cycle in the Tibetan Plateau. This data is mainly obtained through field observation during the investigation in Gangcha, Qinghai Province in 2020. The obtained plant and soil samples were taken back to the laboratory for preliminary classification and impurity removal, and then dried to constant weight in an oven at 65 ° C. Carbon and nitrogen components in soil and plants were measured. A total of 40 quadrats of 4 typical plots were obtained. The data can be used to reveal the spatial variation of soil and plant carbon and nitrogen components, and understand the distribution of carbon and nitrogen components in soil plant microbial system. (2) Data of soil nutrient composition of grassland horizontal transect in Qinghai Tibet Plateau in 2019. This data is mainly obtained from the field drilling during the sample belt investigation in 2019. The soil samples were taken back to the laboratory for preliminary classification, root removal and stone screening. The soil samples were dried naturally, then mixed evenly and divided into two parts (about 100g each). One part was sieved with 2mm soil sieve to obtain sieved samples, and the other part was ground with ball mill to obtain ground samples. The content elements included: the contents of total C, N, P, K, Fe, Mn, Cu, Zn, CA, Na and total Mg; the contents of available P, K, Fe, Mn, Cu, Zn, CA, Na and Mg. Determination of soil total C and N: the grinding samples were packed, and then the contents of total C and N were determined by chnos elemental analyzer (vario El III, GmbH, Hanau, Germany). Determination of total elements in soil: the grinding samples were pressed by a tablet press, and then the contents of total P, K, Fe, Mn, Cu, Zn, CA, Na and total Mg in the samples were determined by X-ray fluorescence spectrometry (XRF, panalytical Axios max, Almelo, the Netherlands). Determination of soil available elements: the sieved samples were extracted, and the contents of available P, K, Fe, Mn, Cu, Zn, CA, Na and Mg were determined by inductively coupled plasma atomic emission spectrometry (ICAP 6300, Thermo Electron Corporation, Waltham, Ma, USA). A total of 13 transects were obtained. Each plot obtained three soil layers (0-10 cm, 10-20 cm, 20-30 cm). Therefore, there are 117 data of each soil nutrient element (C, N, P, Mn, Zn, etc.) in each quadrat. The data are directly obtained from the field soil samples obtained by this scientific research. After air drying, screening and grinding, the data are determined by the relevant analyzer (above) according to the corresponding test specifications, and the quality is reliable, which can be used to analyze the distribution law of soil carbon and nitrogen content or density in different regions and to evaluate soil nutrient In particular, it can be used for the research and modeling of carbon and nitrogen cycle driven by precipitation change, which has a wide range of application value and application prospects. (3) Vegetation productivity data of grassland horizontal transect in Qinghai Tibet Plateau in 2019. This data is mainly obtained from the field observation during the transect survey in 2019. After obtaining the plant samples, they were taken back to the laboratory for preliminary classification, gravel and other impurities were removed, and then dried in the oven at 65 ° C to constant weight. According to the biomass of the sample, it was converted into the key element of ecosystem carbon cycle vegetation productivity (NPP). A total of 13 transect points and 39 quadrats were obtained. The content elements of the data include aboveground biomass, aboveground biomass and NPP. The unit is gram per square meter; this data is the field observation data obtained from this scientific research, with reliable quality, which can be used to analyze the distribution law of vegetation productivity, vegetation cover, carbon storage assessment of ecosystem in different regions, especially for the study of carbon cycle driven by precipitation change and its modeling, and has a wide application value and application prospect.

0 2021-04-19