Soil Temperature Variability in Complex Terrain Measured Using Fiber‐Optic Distributed Temperature Sensing

PDF HTML阅读 XML下载 导出引用 引用提醒 哀牢山亚热带常绿阔叶林森林土壤温湿特征及其对温度升高的响应 DOI: 10.5846/stxb201403260562 作者: 作者单位: 中国科学院热带森林生态学重点实验室,中国科学院哀牢山生态站;中国科学院哀牢山生态站,日本国立环境研究所,日本,筑波,-,;日本国立环境研究所,日本,筑波,-,中国科学院热带森林生态学重点实验室,中国科学院哀牢山生态站;中国科学院哀牢山生态站,中国科学院热带森林生态学重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 云南省自然科学基金重点项目(2011FA025);国家基金-云南省联合项目(U1202234); 国家基金重大项目(31290220); 中国科学院战略性专项项目(XDA05050601, XDA05050206) Responses of soil temperature, moisture and respiration to experimental warming in a subtropical evergreen broad-leaved forest in Ailao Mountains, Yunnan Author: Affiliation: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为把握土壤温度对未来全球气候变暖的响应程度,评估气候变暖对亚热带森林土壤呼吸的影响,利用在哀牢山亚热带常绿阔叶林中设置的土壤增温和土壤呼吸人工控制实验2011-2013年的实测数据,通过分析,得到如下结果:环境温度的升高不会改变林内的近地层气温、土壤温度和土壤含水量的年变化和日变化规律;冬季和夜间增温效应大于夏季和昼间;增温会导致土壤含水量降低,雨季的效应大于干季;增温导致的升温效应和降低土壤水分效应具有一定的年变化,但是基本没有日变化;所设置的人工增温控制实验的年平均增温在2.0 ℃左右,所设置人工控制实验可以达到5 cm土壤增温2.0 ℃的设计要求,可为其后探讨土壤呼吸对温度升高的响应提供良好的基础保证. Abstract:The soil-surface carbon flux is comparable to that of photosynthesis in terrestrial ecosystems. Much soil carbon flux to the atmosphere is due to rhizosphere metabolism (root respiration) and the decomposition of soil microbes (microbial respiration), which are both very sensitive to temperature. With soil temperatures increasing, soil respiration will increase, thereby accelerating global change. To improve our understanding of the response of soil temperature to future warming and to assess the potential effects of global warming on soil respiration in subtropical forests, we experimentally warmed subtropical evergreen broad-leaved forest soils in Ailao Mountain Southwest, China and measured their respiration. This experiment was conducted at the Ailaoshan Station for Subtropical Forest Ecosystem Studies (24°32'N, 101°01'E; 2480 m above sea level) of the Chinese Ecological Research Network, Jingdong County, Yunnan Province. The annual mean air temperature was 11.0℃, with a maximum monthly mean temperature of 15.3℃ in July and a minimum monthly mean temperature of 5.1℃ in January. The site has strong rainy seasons (May to October) and dry seasons (November to April the following year). The average annual rainfall was 1882 mm, with 1607 mm (85.4% of the annual total) in the rainy season and 274.2 mm in the dry season (14.6% of the annual total). The soil is yellow brown in this area. Litterfall accumulates to 3-7 cm. Soil humus is dark brown and 10-15 cm thick. The mineral soil layer is loose and dominated by soil aggregates. Surface soils have high water permeability and water conservation ability, high organic carbon, and a pH of 4.5-5. Our artificial warming experiment was conducted in a subtropical forest where wind speed and radiation are both low at the surface. A multi-channel automated chamber system was used to continuously monitor soil CO2 effluxes. The system was comprised of 20 automatic chambers (length 90 cm × width 90 cm × height 50 cm) and a control box, and the 20 chambers were divided into 4 treatments (5 chambers per treatment): control, litter removal, trenching, and infrared light warming. The soil efflux of each chamber was measured automatically each hour and environmental factors were measured each half hour. When measuring soil efflux, the chamber was closed for 3 min, then opened for 57 min by opening its lid. Thus, environmental conditions (e.g., wind, rainfall, and litterfall) in chambers were similar to those outside. In the artificial warming experiment, variations in soil temperature and soil water content were observed along with soil respiration. Based on measurements from 2011 to 2013, we concluded that warming did not change the seasonal and diurnal patterns of air temperature near the soil surface, soil temperature, or soil water content of the forest. The warming effects in winter and nighttime were greater than in summer and daytime. Warming decreased soil water content to a larger extent in the rainy season than in the dry season. The temperature increase and soil water decrease resulting from warming had seasonal variations, but not diurnal variations. The experimental warming increased the annual soil temperature by about 2℃; therefore, the warming treatment reached the goal of increasing soil temperature at 5 cm by 2℃. Our infrared warming method achieved a relatively stable warming effect without time lags in soil-temperature variations in the primary subtropical evergreen broad-leaved forest in Ailao Mountain. In this subtropical evergreen broad-leaved forest, soil temperature has previously shown a significant warming trend, so this study can supply information about soil respiration responses. This study also showed that variation in local air temperature, soil temperature, and soil-water content will not change under global warming, but soil-water content will decline with increased temperature, especially in the rainy season. In the forest, soil respiration is affected not only by soil temperature, but also by soil water content. As warming decreases soil water content, the effects of soil water content variation on soil respiration should be examined in future research. 参考文献 相似文献 引证文献

Lightweight structures, such as residential foundations, built on reactive soils experience stability issues due to the soil’s high shrink-swell movements. This study investigated the performance of a full-scale waffle raft foundation (~ 8 m x ~ 10 m) built on a highly reactive site. Spatiotemporal variations of the soil moisture content and temperature outside and underneath the foundation were monitored for more than a year. The shallow soil temperature beneath the foundation fluctuated in response to seasonal weather changes, but no significant spatial variations were observed. Seasonal weather conditions showed a dominant effect on the soil temperature variation outside and beneath the foundation at any depth, and intermittent rainfall events outside the wet/winter season displayed no significant impact on this. The fluctuations in soil moisture content diminish towards the centre of the foundation, although a notable fluctuation is still evident beneath its centre. At varying depths beneath the middle of the foundation, seasonal fluctuations in soil moisture content were observed up to a depth of 2.3 m, but the initial moisture content differences at different depths remained consistent. Overall, this study recommends revisiting the standard design procedure for waffle raft systems in terms of edge distance and depth of design soil suction change determinations.

Studies of soil heat regime are commonly confined to one vertical soil profile. Some studies on the basis of short-term temperature data series reported significant horizontal variation of topsoil horizons due to spatial variation in tree stand densities, plant cover and soil cover heterogeneity. Introduction of programmed automated temperature data loggers facilitated studies of horizontal heterogeneity in soil temperature, i.e. so called temperature fields with long temporal data series. However horizontal variation of soil temperature has not practically been studied in most Russian ecosystems, including those in the West Siberian northern taiga zone. The study of soil temperature regime was carried out in the environs of Noyabrsk (Yamalo-Nenetsky Autonomous Region, Russia) in the four key study sites: climax larch (Larix sibirica Ledeb.) and Scots pine (Pinus sylvestris L.) forests, and flat palsa mire (separately palsa and adjacent hollow). On each study site automated temperature data loggers were used in 5 replicated subsites to measure soil temperature with 0.5°С and record it every 4 hours, i.e. at 1, 5, 9, 13, 17 and 21 o'clock, daily. The loggers were placed at 10 cm soil depth in the root zone. The data from the meteorological station in Noyabrsk were also used in the study. The standard deviation of temperature values, recorded in a study site at one time point, was used as a measure of temperature variation. In all study sites the maximal temperature variation was observed at the beginning of the warm season. In both forest sites soil temperature began varying already after snow thawed, which was most likely due to the heterogeneity of vegetation cover and forest litter; in the pine site soil the heterogeneity of direct solar radiation as a result of the crown shadowing also contributed to temperature variation. The biggest soil temperature variation during this period was observed at the pine forest site, with difference between simultaneous replicated measurements reaching at certain time points as much as 9.6ºС. In the larch study site the corresponding difference in June did not exceed 7-8ºС. The minimal spatial variation of soil temperature in the root zone was observed in hollows of the flat palsa mire site, most likely due to the absence of the microrelief influence and high water saturation. The highest standard deviation values were observed during snow thawing at the beginning of May, when temperature difference between replicated measurements could be as high as 9.5ºС. In June soil temperature variation decreased, staying low during the rest of the year. The palsa soil temperature at the flat palsa mire site and its variation in winter time showed strong response to changing air temperature. This winter variability was most likely due to unevenness of the snow cover thickness, resulting from the pronounced surface microrelief. During show thawing period the root zone temperature varied less, apparently because of even penetration and distribution of snowmelt water throughout the studied soil layer. Rapid soil warming resulted in increased temperature variability, which remained high during entire summer and the beginning of autumn, with differences between replicates being as high as 10.1ºС. Summer variability of soil temperature at this site could be attributed to the permafrost layer, which in different microrelief positions is located at different depth as related to the root zone, thus exerting different influence on the temperature of the soil layers above. The most pronounced effect of diurnal fluctuations of root-zone temperature on its spatial variability was observed in pine forest during entire summer period, whereas on the palsa mire ecosystem it was observed at the beginning of summer during intensive thawing of the seasonally frozen layer.

The temperature of water entering the soil or variation in soil temperature has a direct impact on soil hydraulic conductivity via the effect on water viscosity. In this research, the time variability of soil saturated hydraulic conductivity (Ks) was studied. The relation between soil temperature and fluid viscosity with hydraulic conductivity were also studied. The necessary experiments were conducted on Aboureyhan campus research farm located in Pakdasht, 25 km southeast of Tehran. 18 holes were digged in a plot and saturated hydraulic conductivity of soils were measured in these holes using inverse hole method. Experiments were carried out 12 times from 16-Aug-2005 to 14-Jun-2006. Investigations showed that the lowest value of Ks was obtained in winter when the soil and air temperatures are at minimum and by increasing the soil and air temperatures, these values increased too. Statistical analysis of experiments indicated that soil or air temperatures can considerably affect the results. Using the average of measured Ks to design drainage systems showed that neglecting the time variability of Ks may result in over or underestimating of drain spacing by 18.9% and 23.3%, respectively. Using the average of Ks values which was obtained in soil temperature of 16-20 oC had least effect on drain spacing, so it can be used as an average Ks to design drain spacing. Keywords: Saturated hydraulic conductivity, Time variability, Drainage systems

Management may influence abiotic environments differently across time and spatial scale, greatly influencing perceptions of fragmentation of the landscape. It is vital to consider ap riorithe spatial scales that are most relevant to an investigation, and to reflect on the influence that scale may have on conclusions. While the importance of scale in understanding ecological patterns and processes has been widely recognized, few researchers have investigated how the relationships between pattern and process change across spatial and temporal scales. We used wavelet analysis to examine the multiscale structure of surface and soil temperature, measured every 5 m across a 3820 m transect within a national forest in northern Wisconsin. Temperature functioned as an indicator ‐ or end product ‐ of processes associated with energy budget dynamics, such as radiative inputs, evapotranspiration and convective losses across the landscape. We hoped to determine whether functional relationships between landscape structure and temperature could be generalized, by examining patterns and relationships at multiple spatial scales and time periods during the day. The pattern of temperature varied between surface and soil temperature and among daily time periods. Wavelet variances indicated that no single scale dominated the pattern in temperature at any time, though values were highest at finest scales and at midday. Using general linear models, we explained 38% to 60% of the variation in temperature along the transect. Broad categorical variables describing the vegetation patch in which a point was located and the closest vegetation patch of a different type (landscape context) were important in models of both surface and soil temperature across time periods. Variables associated with slope and microtopography were more commonly incorporated into models explaining variation in soil temperature, whereas variables associated with vegetation or ground cover explained more variation in surface temperature. We examined correlations between wavelet transforms of temperature and vegetation (i.e., structural) pattern to determine whether these associations occurred at predictable scales or were consistent across time. Correlations between transforms characteristically had two peaks; one at finer scales of 100 to 150 m and one at broader scales of >300 m. These scales differed among times of day and between surface and soil temperatures. Our results indicate that temperature structure is distinct from vegetation structure and is spatially and temporally dynamic. There did not appear to be any single scale at which it was more relevant to study temperature or this patternprocess relationship, although the strongest relationships between vegetation structure and temperature occurred within a predictable range of scales. Forest managers and conservation biologists must recognize the dynamic relationship between temperature and structure across landscapes and incorporate the landscape elements created by temperature-structure interactions into management decisions.

One of the most reliable features of natural systems is that they change through time. Theory predicts that temporally fluctuating conditions shape community composition, species distribution patterns, and life history variation, yet features of temporal variability are rarely incorporated into studies of species-environment associations. In this study, we evaluated how two components of temporal environmental variation-variability and predictability-impact plant community composition and species distribution patterns in the alpine tundra of the Southern Rocky Mountains in Colorado (USA). Using the Sensor Network Array at the Niwot Ridge Long-Term Ecological Research site, we used in situ, high-resolution temporal measurements of soil moisture and temperature from 13 locations ("nodes") distributed throughout an alpine catchment to characterize the annual mean, variability, and predictability in these variables in each of four consecutive years. We combined these data with annual vegetation surveys at each node to evaluate whether variability over short (within-day) and seasonal (2- to 4-month) timescales could predict patterns in plant community composition, species distributions, and species abundances better than models that considered average annual conditions alone. We found that metrics for variability and predictability in soil moisture and soil temperature, at both daily and seasonal timescales, improved our ability to explain spatial variation in alpine plant community composition. Daily variability in soil moisture and temperature, along with seasonal predictability in soil moisture, was particularly important in predicting community composition and species occurrences. These results indicate that the magnitude and patterns of fluctuations in soil moisture and temperature are important predictors of community composition and plant distribution patterns in alpine plant communities. More broadly, these results highlight that components of temporal change provide important niche axes that can partition species with different growth and life history strategies along environmental gradients in heterogeneous landscapes.

Soil moisture and temperature conditions play an important role in plant growth. Modeling soil moisture and temperature is useful for predicting crop yields and risks. In this study, the Soil Temperature and Moisture Model (STM2) was used to predict soil moisture and temperature at several depths: 15, 30, 45, and 60 cm for soil moisture and 10, 25, and 50 cm for soil temperature. The objective of this study was to assess the prediction efficiency of STM2 according to soil depth and phenology. The STM2 uses soil texture data along with average daily weather data (maximum and minimum air temperature and precipitation) as inputs. During the 2008 and 2010 growing seasons, soil moisture and temperature data were measured using monitoring stations located in four agricultural fields in southern Quebec. These fields represent the range of soil texture diversity found in this agricultural area: gravelly, sandy, loamy, and clayey soils. The measurements were used to validate STM2 predictions. The overall performance of soil temperature prediction was better than that for soil moisture. Estimation quality decreased with increasing depth and was higher during the first and third phenological periods for soil moisture. Good performances were observed for the sandy and loamy soils, moderate for the clayey soil, and mostly weak for the gravelly soil. A sensitivity analysis was performed on STM2 data inputs. For soil moisture, bulk density, saturated hydraulic conductivity, and weather data have a great impact while for soil temperature, only weather data have an impact on model estimates. This study showed that STM2 can be used in combination with soil and climatic data sets to reliably predict surface soil moisture and temperature variations in southern Quebec.

Effects of vegetation on soil temperature and water content: Field monitoring and numerical modelling

Soil temperature and soil moisture are key drivers of various soil ecological processes, which implies a significant importance of datasets including their variations in space, depth and time (4D). Current gridded products typically have a low resolution, either spatially or temporally. Here, we aim at modelling and explaining high-resolution soil temperature and soil moisture patterns in 4D for a 400 km2 study area in a heterogeneous landscape. Our target resolution of 10 m in space, 10 cm in depth, and 1 h in time allows capturing small-scale variations as well as short-term dynamics. We used multi-depth soil temperature and soil moisture measurements from 212 locations and linked them to 45 potential predictors, representing meteorological conditions, soil parameters, vegetation coverage, and landscape relief. We trained random forest models that were able to predict soil temperature with a mean absolute error of 0.93 °C and soil moisture with a mean absolute error of 4.64 % volumetric water content. Continuous model predictions enabled a comprehensive analysis of 4D patterns and confirmed that the selected resolution is essential to capture soil temperature and soil moisture variations at the landscape scale. In addition to a strongly pronounced annual cycle and recognisable influences on the diurnal cycle, there were significant differences between the land uses and patterns due to the relief, which also varied along the depth gradient. By applying interpretable machine learning techniques, we investigated the detailed influence of all drivers and discussed overlapping effects that led to the prediction patterns.

Fiber Optic Liquid Leakage Detection (FOLLD) project has permitted of assessing on the DTS (Distributed Temperature Sensing), the DSTS (Distributed Strain and temperature Sensing) and the DAS (Distributed Acoustic Sensing) capabilities, combined with a Standard Telecom Fiber Optic Cable (FOC), for detecting small pressurized (20 barg) and pre-heated (50 °C) liquid (water) leakages on a buried dummy pipeline. DTS/DSTS real time results demonstrated that the soil disruption, the soil and external environmental temperature variation had an influence on leakage detection results robustness. Consequently, only the first three (3) trials out of the ten (10) trials provide some comprehensive results. Real time results shown that two (2) out of three (3) DSTS devices were able to detect a leakage up to twenty (20) km with a detection success rate of 67% in the position P1 or P2 or P3. One (1) out of two (2) DTS device detects up to twenty (20) km with a detection success rate that depends on the fiber optic position (67% for P2 or P3 and 33% for P1). Only one (1) DSTS shows a detection success rate up to fourty (40) km with a detection success rate of 67% in the position P1 or P2 or P3. DTS/DSTS real time results highlight that 100% successful detection rate can be reached up to twenty (20) km with several fiber optic cables in the position: P1/P2 or P1/P3 or P1/P2/P3. For DAS systems, the real time results shown that it was not possible to distinguish a leakage "noise" from other surrounding noise. This was especially due to the water pump noise, which was always occurring simultaneously with the leakage. Only a post processing treatment provide the leakage detection using a DAS technology. Post treatment DTS/DSTS and DAS detection success rate are better than the real time results. This highlight the potential of both technologies. All DTS/DSTS and DAS testing results demonstrated that the detection success rate are Supplier's dependent.

Seasonal changes in root growth of kiwifruit

Five soil management practices (treatments) were applied in a micro-sprinkler irrigated Chardonnay/99 Richter vineyard on a sandy clay loam soil near Robertson, commencing in April 1993 (one year after planting). The effect of the treatments on the soil temperature at a depth of 200 mm was measured on an hourly basis from April 1995 to March 1999. Differences in soil temperature between the un-mulched and mulched treatments, as measured in the grapevine rows, were negligible from late April to the end of August. From mid-September (grapevine bud break) to the end of March, the temperature of the mulched soil was, with the exception of the third week in October, lower than that of the un-mulched soil. Results indicated that soil temperatures during early spring had a slight effect on the onset of grapevine bud break. Mulching minimised the diurnal variation in soil temperature. The annual cover crop did not cause any delay in bud break and kept the soil temperatures below 25°C, with the exception of a three week period just before harvest.

Strip tillage is an effective tillage technique, which included the strip seedbed tilled area (ST-IR) and the straw-covered area between the seedbeds (ST-BR). However, soil hydrothermal conditions and soil disturbance varies with strip tillage widths, which might affect crop growth and yields. Therefore, this study explored the effect of strip tillage width on the soil hydrothermal conditions and soil structure of ST-IR and ST-BR, to determine the optimal strip tillage width. A field experiment with three replicates was conducted to analyze soil moisture and soil temperature variation and to clarify the difference of soil structure in the IR and BR. Three strip tillage widths, 20 cm (ST20), 30 cm (ST30), and 40 cm (ST40), were examined in this study. Soil temperature in both the ST-IR and ST-BR increased as the strip tillage width increased, and the average soil temperature of ST30-IR and ST40-IR in the seedling stage was 2.11°C and 2.62°C higher than that of ST20-IR, respectively. Moreover, the daily soil temperature range in both the IR and BR was greater for ST40 than for ST20 and ST30 in the seedling stage; soil temperature differences in other crop growth stages were small. No significant difference in soil temperature was observed between ST30-IR and ST40-IR. Conversely, soil moisture was greater in ST20-IR and ST30-IR than in ST40-IR; soil moisture was also greater in ST30-BR and ST40-BR than in ST20-BR during the monitoring period. Soil moisture in ST40-IR and ST20-BR increased and decreased more rapidly during rainfall events than in the other treatments. Moreover, soil temperature was higher in the ST-IR than in the ST-BR for all 3 strip tillage widths, and the opposite results were observed for soil moisture. In addition, strip tillage widths had no significant differences on soil structure. In conclusion, a 30 cm strip tillage width had higher soil temperature and remained more soil moisture than other strip tillage widths, so this strip tillage width is thus recommended for use by farmers in Northeast China.

Soil temperature measurements from a Soil Climate Analysis Network (SCAN) monitoring site in the Ozark Highlands Major Land Resource Area (MLRA 116A) were evaluated on landscapes comprising Typic Fragiudults (Scholten series) and Typic Paleudults (Poynor series). The five soil forming factors were similarfor both soils, with the major difference between the adjacent soils being a fragipan in the Scholten series. Air and soil temperatures were collected from a weather station of the USDA-Natural Resources Conservation Service near the border of the mesic soil temperature regime and udic soil moisture regime zone. The mean annual soil temperature observed in the Scholten soil (13.5° C) was0.5° C cooler than the mean annual soil temperature in the Poynor soil (14.0° C). This study showed little difference in mean soil temperatures between soiltypes from January to April and from August to December. During the months of May, June and July, the Poynor mean soil temperature was higher (by 1.1° C, 1.4° C and 1.2° C, respectively) than the Scholten mean soil temperature.According to this study, it is possible that the mean annual soil temperature of fragipan soils is cooler than adjacent soils with no fragipan properties. Thegreatest differences between mean soil temperature and mean air temperature were observed during the months of November (5.1° C for Scholten soil and 5.3°C for Poynor soil); December (5.0° C for Scholten soil and 4.9° C for Poynor soil); and January (4.5° C for Scholten soil and 4.4° C for Poynor soil). The smallestdifference was during the month of March (0° C for Scholten soil and 0.3° C for Poynor soil). This study also indicated that the mean annual soil temperature in the Ozark Highlands can vary by soil series depending on soil properties affecting heat transfer within pedons.

PDF HTML阅读 XML下载 导出引用 引用提醒 沙坡头人工植被演替过程的土壤呼吸特征 DOI: 10.5846/stxb200908011024 作者: 作者单位: 中国科学院寒区旱区与环境工程研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划资助(2009CB421303);中国科学院战略性先导科技专项资助(XDA05050406);国家杰出青年科学基金资助 (40825001);国家自然科学基金资助(40971031,41001025) Soil respiration patterns during restoration of vegetation in the Shapotou area, Northern China Author: Affiliation: Cold and Arid Regions Environmental and Engineering Rsearch Institute, Chinese Adademy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探讨人工植被演替过程对土壤呼吸速率的影响,本文利用碱液吸收法同步测定了腾格里沙漠东南缘1956、1964、1981、1987、1989、2007年始植的人工植被区和2007年新铺设的草方格固沙区及流沙区的土壤呼吸速率变化,同时分析了土壤水分和温度对上述不同样地土壤呼吸的影响。结果表明:1) 总体而言,土壤呼吸速率随着人工植被演替时间的延长而逐渐增大。当土壤含水量较高时,不同始植年代人工植被区的土壤呼吸速率具有显著的差异(P<0.05);当土壤含水量较低时,不同始植年代植被区的土壤呼吸速率没有显著的差异(P>0.05)。2)土壤呼吸速率与土壤含水量呈正相关关系,且相关系数随着人工植被演替时间的延长而逐渐增大。3)利用土壤呼吸速率-土壤温度指数函数关系计算得到不同人工植被演替阶段土壤呼吸速率的Q10值均较低(平均值仅为1.02)。土壤温度对1987、1989年人工植被区内的土壤呼吸速率产生了显著影响(P<0.05),而对其他样地的土壤呼吸速率影响不显著 (P>0.05)。综合说明,人工植被的演替过程改变了土壤呼吸速率大小及其对土壤水分和温度的响应。 Abstract:As one of the important constituents of the carbon cycle, soil respiration is the primary mechanism by which soil carbon is released and an important source of atmospheric CO2, which plays a critical role in regulating atmospheric CO2 concentration and world climate dynamics. Even a small change in soil respiration could profoundly affect the concentration of atmospheric CO2. Numerous studies have been conducted into the relationship between soil respiration, environmental factors (eg. temperature, soil moisture) and anthropogenic disturbance (eg. land use change). However, most of these studies have focused on forest and steppe ecosystems, rather than on desert ecosystems. There is little available information on the effect of vegetation succession on soil respiration in a desert ecosystem. The establishment of artificial sand-binding vegetation in the Shapotou region has changed the landscape from moving dunes to stabilized dunes covered by shrubs, which has, in turn, modified soil respiration patterns. This study has characterized soil respiration patterns and the effects of soil moisture and temperature on soil respiration during vegetation restoration of a desert ecosystem. The study was conducted in the Shapotou revegetated area, located on the southeast fringe of the Tengger Desert (37°32'N, 105°02'E). Soil respiration rates were measured, using the alkali absorption method, in revegetated enclosures, which were constructed in 1956, 1964, 1981, 1987, 1989 and the area was revegetated with Caragana korshinskii in 2007. Soil respiration was also investigated in a sandy area stabilized with straw checkerboard in 2007 and in an area of shifting sand dunes. Based on the traditional space-for-time succession approach, these study plots represented vegetations of different successional stages. The results showed that: 1) In general, soil respiration rates gradually increased with the increasing age of the revegetation. This trend was significant when the soil volume moisture were higher than the mean value (0.0487 cm3 /cm3) for the whole of the experimental period (P<0.05). Soil respiration in the revegetated areas established in 1956, 1964, 1981 was significantly higher than in the areas revegetated in 2007, the area stabilized in 2007 with straw checkerboard and in the shifting sand dunes (P<0.05). No significantly increase was detected when soil volume moisture was lower than the mean value (P>0.05); 2) Soil moisture is an important environmental factor influencing soil respiration. Positive correlations were found between soil volume moisture and the soil respiration rates in every study plot and the correlation coefficients progressively increased with increasing age of the revegetation (P<0.05) and 3) An exponential model has been used to describe the relationship between soil respiration rates and soil temperature. Soil temperature only had a significant effect on soil respiration in the revegetated areas established in 1987 and 1989, but not in the other revegetated enclosures. In every study plot, the Q10 values were uniformly lower than the mean values for temperate regions (1.57). These results suggest that the vegetation restoration process can alter the magnitude of soil respiration rate as well as its response to soil moisture and temperature variations. 参考文献 相似文献 引证文献