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Winter soil CO_2 efflux in two contrasting forest ecosystems on the eastern Tibetan Plateau, China 被引量:2
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作者 Zhenfeng Xu Feifei Zhou +1 位作者 Huajun Yin Qing Liu 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第3期679-686,共8页
Significant CO2 fluxes from snow-covered soils occur in cold biomes. However, little is known about winter soil respiration on the eastern Tibetan Plateau of China. We therefore measured winter soil CO2 fluxes and est... Significant CO2 fluxes from snow-covered soils occur in cold biomes. However, little is known about winter soil respiration on the eastern Tibetan Plateau of China. We therefore measured winter soil CO2 fluxes and estimated annual soil respiration in two contrasting coniferous forest ecosystems (a Picea asperata plantation and a natural forest). Mean winter soil CO2 effluxes were 1.08 μmol m-2 s-1 in the plantation and 1.16 μmol m-2 s-1 in the natural forest. These values are higher than most reported winter soil CO2 efflux values for temperate or boreal forest ecosystems. Winter soil respiration rates were similar for our two forest ecosystems but mean soil CO2 efflux over the growing sea- son was higher in the natural forest than in the plantation. The estimated winter and annual soil effluxes for the natural forest were 176.3 and 1070.3 g m-2, respectively, based on the relationship between soil respiration and soil temperature, which were 17.2 and 9.7 % greater than their counterparts in the plantation. The contributions of winter soil respiration toannual soil efflux were 15.4 % tor the plantation and 16.5R for the natural forest and were statistically similar. Our results indicate that winter soil CO2 efflux from frozen soils in the alpine coniferous forest ecosystems of the eastern Tibetan Plateau was considerable and was an important component of annual soil respiration. Moreover, reforesta- tion (natural coniferous forests were deforested and refor- ested with P. asperata plantation) may reduce soil respiration by reducing soil carbon substrate availability and input. 展开更多
关键词 Winter soil co2 efflux Eastern TibetanPlateau Natural coniferous forest Picea asperataplantation
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Non-growing season soil CO_2 efflux and its changes in an alpine meadow ecosystem of the Qilian Mountains,Northwest China 被引量:1
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作者 ZongQiang CHANG XiaoQing LIU +4 位作者 Qi FENG ZongXi CHE HaiYang XI YongHong SU JianHua SI 《Journal of Arid Land》 SCIE CSCD 2013年第4期488-499,共12页
Most soil respiration measurements are conducted during the growing season.In tundra and boreal forest ecosystems,cumulative,non-growing season soil CO2 fluxes are reported to be a significant component of these syst... Most soil respiration measurements are conducted during the growing season.In tundra and boreal forest ecosystems,cumulative,non-growing season soil CO2 fluxes are reported to be a significant component of these systems' annual carbon budgets.However,little information exists on soil CO2 efflux during the non-growing season from alpine ecosystems.Therefore,comparing measurements of soil respiration taken annually versus during the growing season will improve the accuracy of estimating ecosystem carbon budgets,as well as predicting the response of soil CO2 efflux to climate changes.In this study,we measured soil CO2 efflux and its spatial and temporal changes for different altitudes during the non-growing season in an alpine meadow located in the Qilian Mountains,Northwest China.Field experiments on the soil CO2 efflux of alpine meadow from the Qilian Mountains were conducted along an elevation gradient from October 2010 to April 2011.We measured the soil CO2 efflux,and analyzed the effects of soil water content and soil temperature on this measure.The results show that soil CO2 efflux gradually decreased along the elevation gradient during the non-growing season.The daily variation of soil CO2 efflux appeared as a single-peak curve.The soil CO2 efflux was low at night,with the lowest value occurring between 02:00-06:00.Then,values started to rise rapidly between 07:00-08:30,and then descend again between 16:00-18:30.The peak soil CO2 efflux appeared from 11:00 to 16:00.The soil CO2 efflux values gradually decreased from October to February of the next year and started to increase in March.Non-growing season Q10 (the multiplier to the respiration rate for a 10℃ increase in temperature) was increased with raising altitude and average Q10 of the Qilian Mountains was generally higher than the average growing season Q10 of the Heihe River Basin.Seasonally,non-growing season soil CO2 efflux was relatively high in October and early spring and low in the winter.The soil CO2 efflux was positively correlated with soil temperature and soil water content.Our results indicate that in alpine ecosystems,soil CO2 efflux continues throughout the non-growing season,and soil respiration is an important component of annual soil CO2 efflux. 展开更多
关键词 non-growing season soil co2 efflux spatial and temporal variation alpine meadow Q10 values Qilian Mountains
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Influence of environmental,root,and stand parameters on soil surface CO_2 efflux in a Populus euphratica of desert forest in extreme arid region 被引量:1
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作者 ZongQiang Chang,Qi Feng,YongHong Su,JianHua Si, HaiYang Xi,ShengKui Cao,Rui Guo Alashan Desert Eco-Hydrology Experimental Research Station,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China. 《Research in Cold and Arid Regions》 2009年第4期348-355,共8页
Spatial variation in soil surface CO2 efflux was measured in a stand of Populus euphratica in the Ejina Oasis of desert riparian forest in the extreme arid region in northwestern China from April 2007 through October ... Spatial variation in soil surface CO2 efflux was measured in a stand of Populus euphratica in the Ejina Oasis of desert riparian forest in the extreme arid region in northwestern China from April 2007 through October 2007.Measurements were taken with a gas-exchange analyzer linked to a soil-respiration chamber.The mean soil CO2 efflux in the stand was 2.71 μmol/(m2·s) during the growing season and 1.38 μmol/(m2·s) in the nongrowing season.The seasonal maximum (end of May through early June) andminimum (October) CO2 efflux were 3.38 and 0.69 μmol/(m2·s),respectively.The diurnal fluctuation of CO2 efflux was relatively small (< 20 percent),with theminimum appearing around 05:00 and the maximum around 15:00.Linear regression analysis showed soil-surface CO2 efflux to be most highly correlated with soil temperature (R2=0.435) and soil moisture (R2=0.213).When all variables were considered simultaneously,only soil temperature (R2=0.378),soil moisture (R2=0.147),and root volume density (R2=0.021) explained a significant amount of variance in soil surface CO2 efflux.Stand volumes were not correlated with soil CO2 efflux on our sites. 展开更多
关键词 soil surface co2 efflux Populus euphratica Oliv PARAMETERS Ejina Oasis
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Soil CO2 Efflux Dynamics and Its Relationship with the Environmental Variables in a Sub-Tropical Mixed Forest
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作者 Deepa Dhital Rabina Manandhar +1 位作者 Puruswattam Manandhar Sanu Raja Maharjan 《Open Journal of Forestry》 2022年第3期312-336,共25页
Soil CO<sub>2</sub> efflux is an ongoing process of respiration from soil;plant parts/ microbes below the ground to the atmosphere which is known for faster cycling of carbon sources. A large portion of ca... Soil CO<sub>2</sub> efflux is an ongoing process of respiration from soil;plant parts/ microbes below the ground to the atmosphere which is known for faster cycling of carbon sources. A large portion of carbon sequestered and fixed by forests is returned to the atmosphere through soil CO<sub>2</sub> efflux and multiple controlling parameters mainly temperature, precipitation, and growth factors interact with the soil CO<sub>2</sub> efflux variation. This study assessed the soil CO<sub>2</sub> efflux every month for consecutive 2-years (August 2015 to July 2017) by using the closed chamber method to determine the role of ecological parameters that govern the soil CO<sub>2</sub> efflux and its temporal modification in a sub-tropical mixed forest of central region in Nepal. The results of this study manifested that soil CO<sub>2</sub> efflux accounted 63.2% (y = 31.96e<sup>0.128x</sup>), 71.3% (y = 44.77e<sup>0.123x</sup>) and 64.5% (y = 44.11e<sup>0.117x</sup>) variations in soil temperature with significantly (p < 0.05) exponential positive relation in the year 2015/2016, 2016/2017 and the two years when merged. And the temperature sensitivity value (Q<sub>10</sub>) of the soil CO<sub>2</sub> efflux was 3.6, 3.4, and 3.2, respectively. Soil water content also expressed significantly (p < 0.05) positive exponential effect on soil CO<sub>2</sub> efflux and accounted 62.0% (y = 138.3e<sup>0.057x</sup>), 46.1% (y = 88.42e<sup>0.052x</sup>) and 40.5% (y = 133.1e<sup>0.0447x</sup>) in its variability in different years and the merged years. Evident variations of soil CO<sub>2</sub> efflux, soil temperature, soil water content, and litter were observed in the forest seasonally and inter-annually. Two years mean total annual soil CO<sub>2</sub> efflux of the forest was estimated at 904.76 g C&#183;m<sup>-2</sup>&#183;y<sup>-1</sup>. The study revealed that sub-tropical forests could be more influenced by precipitation regimes in progressing warm climates i.e. vulnerable to climate change, illustrating the comprehensive dynamics of the representative forest carbon cycle in the tropical region. 展开更多
关键词 soil co2 efflux Environmental Parameters Temperature Sensitivity (Q10) Sub-Tropical Forest Climate Change
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长白山阔叶红松林土壤CO_2释放通量 被引量:14
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作者 林丽莎 韩士杰 王跃思 《东北林业大学学报》 CAS CSCD 北大核心 2005年第1期11-13,共3页
利用静态箱/气相色谱法对长白山阔叶红松林林下土壤CO2释放通量进行了测定.结果表明:土壤CO2通量年变化具有明显的季节差异,在一年中温度最高的7~8月份,土壤CO2释放通量值最大,可达770.29mg·m-2·h-1,而在最冷的1~2月份土壤... 利用静态箱/气相色谱法对长白山阔叶红松林林下土壤CO2释放通量进行了测定.结果表明:土壤CO2通量年变化具有明显的季节差异,在一年中温度最高的7~8月份,土壤CO2释放通量值最大,可达770.29mg·m-2·h-1,而在最冷的1~2月份土壤CO2释放通量最小,其通量仅为33.23 mg·m-2·h-1.土壤CO2通量的变化与大气、土壤表层、地下5 cm处温度的变化呈明显的正相关关系:CO2释放通量随温度的升高呈指数函数上升;地下5 cm处温度与土壤CO2通量的相关性最显著(R=0.80,P<0.001,n=61);CO2释放通量与土壤含水量之间也存在着正相关关系,但显著性不高. 展开更多
关键词 土壤co2 长白山阔叶红松林 月份 土壤表层 温度 土壤含水量 地下 释放通量 正相关关系 大气
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土壤表层CO_2的释放与土壤水分波动 被引量:1
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作者 朴河春 洪业汤 袁芷云 《矿物岩石地球化学通报》 CAS CSCD 1999年第3期13-16,共4页
贵州虽地处雨量充沛、气候潮湿的亚热带,但近年来旱地土壤往往出现明显的干湿循环现象,这是因为:1)森林植被遭到破坏,使其对气候的调节功能大不如前,导致出现多年气候异常,最大的年降雨量与最小的年降雨量之间相差500mm以... 贵州虽地处雨量充沛、气候潮湿的亚热带,但近年来旱地土壤往往出现明显的干湿循环现象,这是因为:1)森林植被遭到破坏,使其对气候的调节功能大不如前,导致出现多年气候异常,最大的年降雨量与最小的年降雨量之间相差500mm以上,旱涝灾害频繁;2)喀斯特地貌土... 展开更多
关键词 土壤表层co2释放通量 土壤水分波动 土壤可溶性有机碳
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Soil temperature and moisture sensitivities of soil CO_2 efflux before and after tillage in a wheat field of Loess Plateau,China 被引量:7
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作者 Hongxing Zhang Xiaoke Wang +6 位作者 Zongwei Feng Junzhu Pang Fei Lu Zhiyun Ouyang Hua Zheng Wenzhao Liu Dafeng Hui 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第1期79-86,共8页
As a conventional farming practice, tillage has lasted for thousands of years in Loess Plateau, China. Although recent studies show that tillage is a prominent culprit to soil carbon loss in croplands, few studies hav... As a conventional farming practice, tillage has lasted for thousands of years in Loess Plateau, China. Although recent studies show that tillage is a prominent culprit to soil carbon loss in croplands, few studies have investigated the influences of tillage on the responses of soil CO2 efflux (SCE) to soil temperature and moisture. Using a multi-channel automated CO2 efflux chamber system, we measured SCE in situ continuously before and after the conventional tillage in a rain fed wheat field of Loess Plateau, China. The changes in soil temperature and moisture sensitivities of SCE, denoted by the Q10 value and linear regression slope respectively, were compared in the same range of soil temperature and moisture before and after the tillage. The results showed that, after the tillage, SCE increased by 1.2-2.2 times; the soil temperature sensitivity increased by 36.1%-37.5%; and the soil moisture sensitivity increased by 140%-166%. Thus, the tillage-induced increase in SCE might partially be attributed to the increases in temperature and moisture sensitivity of SCE. 展开更多
关键词 soil co2 efflux Loess Plateau moisture sensitivity temperature sensitivity TILLAGE wheat field
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Response of soil CO_2 efflux to precipitation manipulation in a semiarid grassland 被引量:2
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作者 Xiaorong Wei Yanjiang Zhang +6 位作者 Jian Liu Hailong Gao Jun Fan Xiaoxu Jia Jimin Cheng Mingan Shao Xingchang Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第7期207-214,共8页
Soil CO_2efflux(SCE) is an important component of ecosystem CO_2 exchange and is largely temperature and moisture dependent, providing feedback between C cycling and the climate system. We used a precipitation manip... Soil CO_2efflux(SCE) is an important component of ecosystem CO_2 exchange and is largely temperature and moisture dependent, providing feedback between C cycling and the climate system. We used a precipitation manipulation experiment to examine the effects of precipitation treatment on SCE and its dependences on soil temperature and moisture in a semiarid grassland. Precipitation manipulation included ambient precipitation, decreased precipitation(- 43%), or increased precipitation(+ 17%). The SCE was measured from July2013 to December 2014, and CO_2 emission during the experimental period was assessed.The response curves of SCE to soil temperature and moisture were analyzed to determine whether the dependence of SCE on soil temperature or moisture varied with precipitation manipulation. The SCE significantly varied seasonally but was not affected by precipitation treatments regardless of season. Increasing precipitation resulted in an upward shift of SCE–temperature response curves and rightward shift of SCE–moisture response curves,while decreasing precipitation resulted in opposite shifts of such response curves. These shifts in the SCE response curves suggested that increasing precipitation strengthened the dependence of SCE on temperature or moisture, and decreasing precipitation weakened such dependences. Such shifts affected the predictions in soil CO_2 emissions for different precipitation treatments. When considering such shifts, decreasing or increasing precipitation resulted in 43 or 75% less change, respectively, in CO_2 emission compared with changes in emissions predicted without considering such shifts. Furthermore, the effects of shifts in SCE response curves on CO_2 emission prediction were greater during the growing than the non-growing season. 展开更多
关键词 soil co2 efflux response curve soil moisture soil temperature Precipitation regimes Semiarid grassland soil co2 efflux
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Variation in soil organic matter accumulation and metabolic activity along an elevation gradient in the Santa Rosa Mountains of Southern California, USA
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作者 Amitava CHATTERJEE George D JENERETTE 《Journal of Arid Land》 SCIE CSCD 2015年第6期814-819,共6页
Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic ... Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic matter and metabolic rates along an elevation gradient(289–2,489 m) in the Santa Rosa Mountains, California, USA from subalpine and montane pine forests through chaparral to desert. From base(289 m) to summit(2,489 m), 24 sites were established for collecting soil samples under canopies and inter-canopy spaces, at 0–5 and 5–15 cm soil depths increments. Soil organic matter(SOM) content was determined using weight loss on ignition at 550°C and soil CO2 efflux(R) was measured at day 5(R5) and day 20(R20) of incubation. Changes in SOM content along the elevation gradient showed a significant relationship(P〈0.05) but R5 and R20 were not related to either elevation or SOM content. However, the ratio of R and SOM(R5/SOM) showed a strong relationship across the mountains at both soil depths. R5/SOM, as an indicator of carbon use efficiency, may be applicable to other semi-arid transects at larger scale modeling of soil metabolic processes. 展开更多
关键词 elevation gradient soil organic matter co2 efflux metabolic activity
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Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China 被引量:17
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作者 Xu-Li Tang Guo-Yi Zhou +4 位作者 Shu-Guang Liu De-Qiang Zhang Shi-Zhong Liu Jiong Li Cun-Yu Zhou 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2006年第6期654-663,共10页
The spatial and temporal variations in soil respiration and its relationship with biophysical factors In forests near the Tropic of Cancer remain highly uncertain. To contribute towards an Improvement of actual estima... The spatial and temporal variations in soil respiration and its relationship with biophysical factors In forests near the Tropic of Cancer remain highly uncertain. To contribute towards an Improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured In three successional subtropical forests at the Dlnghuahan Nature Reserve (DNR) In southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and Its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared In successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates In the cool dry season (October-March). Soil respiration measured at these forests showed a clear Increasing trend with the progressive succession. Annual mean (± SD) soil respiration rate In the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm^2 per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm^2 per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm^2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation In DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture Increased with progressive succession processes. This increase is caused, in part, by abundant respirators In advanced-successional forest, where more soil moisture is needed to maintain their activities. 展开更多
关键词 Dinghushan Nature Reserve moisture sensitivity Q10 soil co2 efflux soil respiration subtropical forests successional forests temperature sensitivity Tropic of Cancer.
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