Photosynthesis dataset of populus euphratica in the downstream of Tarim River

Photosynthesis of Populus euphratica is mainly affected by atmospheric CO2 concentration, intercellular CO2 concentration, photosynthetic active radiation and leaf temperature when groundwater level is deep and shallow, but with the decrease of groundwater level, atmospheric CO2 concentration and photosynthetic active radiation become the main factors limiting photosynthesis of Populus euphratica. This is because when the groundwater depth is low, the groundwater supply is sufficient, and the leaves are not limited by the water supply. When the photosynthetic effective radiation is strong, the air temperature and leaf temperature are relatively high, and the relative humidity of the air is small. At this time, the photosynthesis and transpiration are both strong. Stomata mainly adapt to strong transpiration by increasing stomatal conductance, i.e. reducing stomatal resistance. At the same time, CO2 in the air continuously enters cells through open stomata, and becomes the raw material for photosynthesis together with intercellular CO2, thus causing the decrease of CO2 concentration in the air and intercellular space, which is the CO2 supply limitation that often causes photosynthesis inhibition in photosynthesis. However, when subjected to water stress, the supply of CO2 is no longer the main reason for limiting photosynthesis. When the photosynthetic effective radiation increases, the net photosynthetic rate, transpiration rate and stomatal conductance all increase. When the supply of CO2 concentration is relatively sufficient, photosynthesis will be slowed down due to the shortage of water, another necessary raw material for photosynthesis. Water use efficiency and water productivity of plants are of great practical significance for measuring and screening species in arid regions. The flow rate was 400μmol/ s and the leaf temperature was kept at 26°C using the L I-6400 portable photosynthesis analyzer, the CO2 concentration in the reference chamber was kept at 360μmol/ mol or 720μmol/ mol using the CO2 injection system, and the photosynthetically active radiation (PAR) was set at 2000,1500,1200,1000,500,300,50,0 μ mol/(m2) using the 6400-02B L ED light source. s) 。 Twelve healthy and mature leaves were selected from the east, south, west and north of each Populus euphratica to the middle and upper parts respectively, from 8 :00 to 20 :00, and photosynthetic apparatus Li 6400 (Li 6400, LiCOR, Lincoln, NE, USA) respectively measured the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (gs) and other gas exchange parameters of each leaf, simultaneously measured the atmospheric CO2 concentration (Ca), intercellular CO2 concentration (Ci), photosynthetic effective radiation (Pa r), atmospheric temperature (T a), leaf surface temperature (Tl), air relative humidity (RH) and other parameters, and repeated readings for each leaf 3 times. Water use efficiency (WUE) = Pn/ Tr, stomatal limitation (Ls )= 1-Ci/Ca.

Monitoring dataset of Gansu water quality automatic station (2012-2014)

This data is from the central station of environmental monitoring in gansu province. The data includes three observation elements that are disclosed on the network, namely PH, permanganate index and ammonia nitrogen. The data format is a text file. The first column is the city name, the second column is PH, the third column is permanganate index, the fourth column is ammonia nitrogen, and the fifth column is the observation date. The data include 6 sections of gushuizi, niubei village, wufo temple, shichuan bridge, xincheng bridge and bikou. Gansu section of the Yellow River: xincheng bridge (lanzhou upstream section), shichuan bridge (lanzhou - baiyin junction section), wufo temple (gansu-ningxia junction section), niubei village (gansu-shaanxi junction section).Bailong river wudu section :(section of gushuizi village). Lanzhou city bridge automatic water quality monitoring station is located in xigu district, lanzhou city, gansu province.Point coordinates 103 degrees 35 minutes 02 seconds east longitude, 36 degrees 07 minutes 20 seconds north latitude.Yellow River system (Yellow River main stream), state - controlled provincial boundary section.By lanzhou city environmental monitoring station custody.It's 35 kilometers away.Built in March 2001. PH: the index that characterizes the acidity and alkalinity of water. When the pH value is 7, it is neutral, less than 7 is acidic, and greater than 7 is alkaline.The pH value of natural surface water is generally between 6 and 9. When algae grow in the water, they absorb carbon dioxide due to photosynthesis, resulting in an increase in surface pH value. Permanganate index (CODMn) : the amount consumed when treating surface water samples with potassium permanganate as the oxidant, expressed as mg/L of oxygen.Under these conditions, reductive inorganic substances (ferrous salts, sulphides, etc.) and organic pollutants in water can consume potassium permanganate, which is often used as a comprehensive indicator of the degree of surface water pollution by organic pollutants.Also known as the chemical oxygen demand potassium permanganate method, as distinct from the chemical oxygen demand (COD) of the potassium dichromate method, which is often used to monitor wastewater discharge. Ammonia nitrogen (nh3-n) : ammonia nitrogen exists in water in the form of dissolved ammonia (also known as free ammonia, NH3) and ammonium salt (NH4+). The ratio of the two depends on the pH value and water temperature of the water, and the content of ammonia nitrogen is expressed by the amount of N element.The main sources of ammonia nitrogen in the water are domestic sewage and some industrial wastewater (such as coking and ammonia synthesis industry) and surface runoff (mainly refers to the fertilizer used in farmland entering rivers, lakes, etc.). This data will be updated automatically and continuously according to the data source.

1:4 million map of the Glaciers, Frozen Ground and Deserts in China (2006)

The compilation basis of frozen soil map includes: (1) frozen soil field survey, exploration and measurement data; (2) aerial photo and satellite image interpretation; (3) topo300 1km resolution ground elevation data; (4) temperature and ground temperature data. Among them, the distribution of permafrost in the Qinghai Tibet Plateau adopts the research results of nanzhuo Tong et al. (2002). Using the measured annual average ground temperature data of 76 boreholes along the Qinghai Tibet highway, regression statistical analysis is carried out to obtain the relationship between the annual average ground temperature and latitude, elevation, and based on this relationship, combined with the gtopo30 elevation data (developed under the leadership of the center for earth resources observation and science and technology, USGS) Global 1 km DEM data) to simulate the annual mean ground temperature distribution over the whole Tibetan Plateau. Taking the annual average ground temperature of 0.5 ℃ as the boundary between permafrost and seasonal permafrost, the boundary between discontinuous Permafrost on the plateau and island Permafrost on the plateau is delimited by referring to the map of ice and snow permafrost in China (1:4 million) (Shi Yafeng et al., 1988); in addition, the division map of Permafrost on the big and small Xing'an Mountains in the Northeast (Guo Dongxin et al., 1981), the distribution map of permafrost and underground ice around the Arctic (b According to rown et al. 1997) and the latest field survey data, the Permafrost Boundary in Northeast China has been revised; the Permafrost Boundary in Northwest mountains mostly uses the boundary defined in the map of ice and snow permafrost in China (1:4 million) (Shi Yafeng et al., 1988). According to the data, the area of permafrost in China is about 1.75 × 106km2, accounting for about 18.25% of China's territory. Among them, alpine permafrost is 0.29 × 106km2, accounting for about 3.03% of China's territory. For more information, please refer to the specification of "1:4 million map of glacial and frozen deserts in China" (Institute of environment and Engineering in cold and dry areas, Chinese Academy of Sciences, 2006)

The HWSD soil texture dataset of the Heihe River Basin (2009)

The data comes from the Harmonized World Soil Database (HWSD) constructed by the Food and Agriculture Organization of the United Nations (FAO) and International Institute for Applied System Analysis in Vienna (IIASA), which released version 1.1 on March 26, 2009. The data resolution is 1 km. The data source in China is 1: 1 million soil data. The soil classification system used is mainly FAO-90. The main fields of the soil property sheet include: SU_SYM90 (name of soil in FAO90 soil classification system) SU_SYM85 (FAO85 classification) T_TEXTURE (top soil texture) DRAINAGE (19.5); ROOTS: String (depth classification to the bottom of the soil with obstacles); SWR: String (characteristics of soil water content); ADD_PROP: Real (specific soil type in the soil unit related to agricultural use); T_GRAVEL: Real (gravel volume percentage); T_SAND: Real (sand content); T_SILT: Real (silt content); T_CLAY: Real (clay content); T_USDA_TEX: Real (USDA Soil Texture Classification); T_REF_BULK: Real (soil bulk density); T_OC: Real (organic carbon content); T_PH_H2O: Real (pH) T_CEC_CLAY: Real (cation exchange capacity of the sticky layer soil); T_CEC_SOIL: Real (soil cation exchange capacity) T_BS: Real (basic saturation); T_TEB: Real (exchangeable base); T_CACO3: Real (carbonate or lime content) T_CASO4: Real (sulfate content); T_ESP: Real (exchangeable sodium salt); T_ECE: Real (conductivity). The attribute field at the beginning of T_ indicates the upper soil attribute (0-30 cm), and the attribute field at the beginning of S_ indicates the lower layer soil attribute (30-100 cm) (FAO 2009). This data provides model input parameters for Earth system modelers, and in agricultural perspective, it can be used to study eco-agricultural divisions, food security, and climate change.