[Spatio-temporal Variation in NEP in Ecological Zoning on the Loess Plateau and Its Driving Factors from 2000 to 2021].

Net ecosystem productivity (NEP) is an important index for the quantitative evaluation of carbon sources and sinks in terrestrial ecosystems. Based on MOD17A3 and meteorological data, the vegetation NEP was estimated from 2000 to 2021 in the Loess Plateau (LP) and its six ecological subregions of the LP (loess sorghum gully subregions:A1, A2; loess hilly and gully subregions:B1, B2; sandy land and agricultural irrigation subregion:C; and earth-rock mountain and river valley plain subregion:D). Combined with the terrain, remote sensing, and human activity data, Theil-Sen Median trend analysis, correlation analysis, multiple regression residual analysis, and geographic detector were used, respectively, to explore the spatio-temporal characteristics of NEP and its response mechanism to climate, terrain, and human activity.

[Detection of Influencing Factors of Spatial Variability of Soil Respiration in Pangquangou Nature Reserve].

Soil respiration is an important process in maintaining global carbon balance. Taking the Pangquangou Nature Reserve as the research area, based on the field measurement of soil respiration () data combined with altitude (ELE), soil temperature (), soil moisture (SWC), normalized vegetation index (NDVI), slope (slope), soil total carbon (C), total nitrogen (N), and soil bulk density (BD), we analyzed the main driving forces and interactions of spatial differentiation by using the geographic detector model. The results showed that:① the spatial variation of and its influencing factors in the study area was moderate.

[Characteristics of Heavy Metal Pollution and Ecological Risk Evaluation of Indoor Dust from Urban and Rural Areas in Taiyuan City During the Heating Season].

The presence of heavy metals in indoor dust is a world-wide concern owing to its negative impact on humans. In this study, we collected indoor dust samples from urban and rural residential areas during the heating season in Taiyuan City. We then identified the concentrations of 11 heavy metals (Cd, Co, Cr, Pb, Mn, Ni, Cu, Zn, V, As, and Hg) using inductively coupled plasma-mass spectrometry.

[Effect of Fertilization on Soil Respiration and Its Temperature Sensitivity in a Sorghum Field].

The characteristics of soil respiration under the condition of fertilization have not been fully understood,especially for a long-term fertilization condition. In this study we measured both soil respiration using an LI-COR-6400-09 soil chamber attached to LI-COR-6400 portable photosynthesis system, and the vegetation spectrum using an ASD FieldSpec HandHeld2, in five different fertilization treatment fields. The soil respiration () and vegetation spectrum were simultaneously measured with two samples per month in the growing season in 2016 and 2017.

[Effect of the Sampling Scale and Number on the Heterogeneity of Soil Respiration in a Mixed Broadleaf-conifer Forest].

By upscaling the observed results at the plot scale, the carbon efflux from soils in a region can be estimated. Therefore, it is very important to investigate the spatial relations of soil respiration () and its environment and to evaluate the effect of the sampling scale and number on the accuracy of measurement at the spatial scale. Based on field observation data for a mixed broadleaf-conifer forest in the Pangquangou Nature Reserve of the Shanxi Province, two analysis methods, that is, traditional statistics and geostatistics, were used to analyze the influence of the soil water content (), soil temperature (), litter mass (), litter moisture content (), soil total carbon (C), total nitrogen (N), and ratio of C/N and sulfur (S) on the heterogeneity at 4, 2, and 1 m sampling scales.

[Effects of Microbial Diversity on Soil Carbon Mineralization].

Soil microbial community plays an important role in ecosystem functions; however, little is known about the importance of microbial diversity to the ecosystems. In this study, serial dilution of soil suspension (10, 10, and 10) was performed and inoculated into the sterilized soils that form the broadleaf mixed forests in Pangquangou. The change in the carbon mineralization rate and the pattern of the carbon source utilization were studied by titration, Biolog Eco, and other experimental methods.

[Effects of Canopy Temperature on Carbon Dioxide Exchange of Winter Wheat in Taiyuan Basin].

We measured daily changes of carbon dioxide exchange in a winter wheat site in Taiyuan basin using chamber method for two years and analyzed relationships between environmental factors affecting carbon exchange of the wheat, including air temperature (), soil temperature (), canopy radiation temperature () and carbon exchange of the wheat on daily and seasonal scales. The results showed that variations of both and on daily and seasonal scales were consistent with a correlation coefficient of above 0.90.

[Interannual Variations of Soil Respiration and Its Temperature Sensitivity in an Orchard in Jinci Region of Taiyuan City].

Jinci area of Taiyuan city is a former hometown of rice, and with the cutoff of the Jinci spring the land use in the area changed fundamentally from original paddy rice to corn or orchard use. So it is very important to investigate soil respiration after land use change and to analyze the relationship between soil respiration () and soil temperature () and soil water content (SWC), and to estimate soil carbon dioxide efflux in the region. For this purpose, we measured for seven years (2006 to 2012) with an interval of 1 to 3 times per month from March to December in a field originally for rice but now Chinese jujube, and analyzed seasonal, annual variations of and relationships between and both and SWC.

[Spatial Heterogeneity of Soil Respiration in a Larch Plantation of North China at Different Sampling Scales].

Based on observations of soil respiration rate (Rs) and both biotic and abiotic factors in Pangquangou Nature Reserve at three sampling scales (4, 2, and 1 m), we studied the spatial heterogeneity of Rs and the factors, and analyzed impacts of soil temperature at the 5, 10 and 15 cm depth (T5, T10, T15), soil moisture over the depth of 0-10 cm (Ws), and soil total nitrogen (N), soil total organic carbon (C), ratio of carbon and nitrogen (C/N), soil total sulfur (S), litter fall mass (Lw) and litter fall moisture (Lm) on the spatial heterogeneity of Rs, respectively. We also calculated the minimum sampling number of all the factors at different confidence levels and under the responding estimation accuracy. The results showed that: (1) the spatial heterogeneity of C/N at 4 m sampling scale, Ws at 2 m sampling scale and T10, T15 at 1 m sampling scale had low variability, while the spatial variation of Rs and other related factors had medium variability.

[Spatial Heterogeneity of Soil Respiration in a Planted Larch Forest in Shanxi Plateau].

Based on the data from a planted larch forest in Panquangou Natural Reserve of Shanxi Province, at three sampling scales (4, 2, and 1 m, respectively), soil respiration (Rs) and its affecting factors including soil temperature at 5 cm (T5), 10 cm (T10), and 15 cm (T15) depths, soil water content (Ws), litter mass (Lw), litter moisture (Lm), soil total carbon (C), and soil total nitrogen ( N) were determined. The spatial heterogeneities of Rs and the environmental factors were further analyzed and their intrinsic correlations were established. The results of traditional statistics showed that the spatial variations of Rs and the all measured factors were in the middle range; Rs were highly significantly positively correlated with T10, T15, and N (P < 0.

[Spatial heterogeneity of soil respiration in a subalpine meadow at different sampling scales].

At four different sampling scales (10, 5, 2.5 and 1.25 m) we measured soil respiration and the environmental factors affecting soil respiration in a subalpine meadow at Yundin mountain of Shanxi province.

[Studies on spatial heterogeneity of soil respiration in a subalpine meadow].

We measured soil respiration (R) and the environmental factors influencing Rs including soil temperature ( T, ) , soil water content (SWC) and soil organic carbon (SOC) in a subalpine meadow in Yundin mountain of Shanxi province, and performed an analysis of the heterogeneity of Rs, T10 and SWC and SOC as well as their relationships using both traditional statistics and geostatistics methods. The results from traditional statistics showed that the measured data of R and the environmental factors exhibited a normal distribution with variation coefficients ranging between 12% and 24%. The variation of all the measured factors was in the middle range.

[Effect of vegetation types on soil respiration characteristics on a smaller scale].

Soil respiration was measured from April 2005 to December 2007 using a LICOR-6400-09 chamber connecting a LiCor-6400 portable photosynthesis system at 3 sites with same elevation and soil texture but different vegetation types. The results indicated that seasonal trend of soil respiration showed a distinct temporal change with the higher values in summer and autumn months and the lower values in winter and spring. Annual means (March to December) of soil respiration for 3 the sampling sites were(3.