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生物质炭和秸秆配合施用对土壤有机碳转化的影响 总被引:6,自引:2,他引:4
为探讨生物质炭和秸秆碳输入对土壤碳构成和转化的影响,通过室内培养试验,研究了单施生物质炭、秸秆及两者配合施入下土壤二氧化碳的释放特征以及土壤微生物碳和有机碳的变化.结果表明,秸秆有机碳在土壤中的矿化率为21.50%(2%添加水平),远大于等量生物质炭的矿化率(8.09%);施用等量(占4%土重)生物质炭和秸秆,培养200 d后土壤有机碳含量分别为24.40 g·kg~(-1)、17.40 g·kg~(-1),表明生物质炭对有机碳的提升作用大于秸秆的.施用生物质炭对土壤固有有机碳有一定的保护作用,生物质炭与秸秆配合施用促进了秸秆的矿化,对有机碳矿化影响的交互效应为正值.施用秸秆能大幅度增加土壤微生物碳,而生物质炭对土壤微生物碳影响小;秸秆和生物质炭配合也增加了土壤微生物碳,但其交互效应与培养时间、施用量等有关,可正可负. 相似文献
43.
The Assessment of Atmospheric Pollution using Satellite Remote Sensing Technology in Large Cities in the Vicinity of Airports 总被引:1,自引:0,他引:1
D. G. Hadjimitsis A. Retalis C. R. I. Clayton 《Water, Air, & Soil Pollution: Focus》2002,2(5-6):631-640
This paper investigates the potential of usingsatellite remotely sensed imagery for assessing atmosphericpollution. A novel approach, which comprised radiativetransfer calculations and pseudo-invariant targets fordetermining aerosol optical thickness has been developed.The key parameter for assessing atmospheric pollution inphotochemical air pollution studies is the aerosol opticalthickness. The need for identifying suitable pseudo-invariantobjects in satellite images of urban areas is of great interest for increasing the potential of earthobservation for monitoring air pollution in such areas. Theidentification of large water bodies and concrete apronsthat can serve as suitable dark and bright targetsrespectively in different geographical areas wasdemonstrated in this study. This study added evidence onthe correlation found between the visibility valuesmeasured at Heathrow Airport area during satellite overpassand aerosol optical thickness derived from Landsat-5 TMband 1 images. 相似文献
44.
贡嘎山麦吊杉群落结构的研究 总被引:3,自引:0,他引:3
吴宁 《应用与环境生物学报》1995,1(4):334-342
麦吊杉群落在贡嘎山东坡海拔2200~2800m之间呈带状分布。本文从群落分布区的自然环境、群落外貌和结构特征,以及种群结构等方面对其进行了研究。归纳出生活型组成特征、麦吊杉种群高度和胸径的生长规律,以及立木级分布特点,分析了群落的垂直结构,最后与北方的暗针叶林作了比较分析,并讨论了群落的动态特点。 相似文献
45.
暗处理和自然光修复对菹草叶片过氧化物酶和过氧化氢酶活性的影响 总被引:1,自引:0,他引:1
以自然光为对照,在预先进行暗处理,然后进行光修复的条件下,对菹草(Potamogeton crispus)过氧化物酶(POD)和过氧化氢酶(CAT)活性及其与处理时间的关系进行了初步研究,结果表明:POD活性随着暗处理时间的延长而增强,随着光修复时间的延长而减弱;暗处理与对照相比,菹草叶片POD活性之间差异不显著;光修复与对照相比,前3天内,POD活性差异不显著,随着光修复时间的延长,POD活性出现显著差异(^*P〉0.05)。CAT活性在暗处理和光修复中都一直低于对照值;暗处理开始2天,活性开始上升,达到最大值后下降,与对照菹草叶片CAT活性比较,前6天差异显著(^*P〉0.05),第7天为差异极显著(^**P〉0.01);在光修复过程中,CAT活性第1天明显下降,与对照相比,除第3天表现出差异性显著(^*P〉0.05)以外,其它均差异不显著。 相似文献
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47.
E. N. Valendik J. C. Brissette Ye. K. Kisilyakhov R. J. Lasko S. V. Verkhovets S. T. Eubanks I. V. Kosov A. Yu. Lantukh 《Mitigation and Adaptation Strategies for Global Change》2006,11(4):883-896
Mechanical treatment and prescribed fire were used to restore a mixed conifer stand (Picea-Abies-Pinus) following mortality from an outbreak of Siberian moth (Dendrolimus superans sibiricus). Moth-killed stands often become dominated by Calamagrostis, a sod-forming grass. The large amount of woody debris and the sod hinder coniferous seedling establishment and development
as well as creating conditions favorable to the establishment and propagation of wildfires. Fire has been demonstrated to
be an effective method of reducing woody debris and eliminating sod, but the random nature and timing of wildfires often do
not create conditions favorable for conifer regeneration. Our study was conducted in a mature fir dominated stand that died
during an outbreak 6–8 years previously with most of the dead trees still standing. A bulldozer drove through the stand downing
standing snags in late summer with 15–20 m between passes. Snags knocked down by the bulldozer and additional snag fall throughout
the following winter increased downed dead wood 50–60% and large downed dead wood 80% compared to an adjacent untreated area.
In June, a prescribed fire was set and fuel load consumption averaged 70%. Average soil temperatures during the burn ranged
from 47 ∘C at a depth of 2 cm to 10 ∘C at 10 cm; hot enough to kill the grass. Following treatment, the potential for wildfire was reduced and the area was suitable
for either natural conifer regeneration or planting without further mechanical site preparation. 相似文献
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49.
Guochen ZHENG Jianzheng LI Feng ZHAO Liguo ZHANG Li WEI Qiaoying BAN Yongsheng ZHAO 《Frontiers of Environmental Science & Engineering》2012,6(1):125-130
To investigate the influence of illumination on the fermentative hydrogen production system, the hydrogen production efficiencies of two kinds of anaerobic activated sludge (floc and granule) from an anaerobic baffled reactor were detected under visible light, dark and light-dark, respectively. The 10 mL floc sludge or granular sludge was respectively inoculated to 100 mL diluted molasses (chemical oxygen demand of 8000 mg·L-1) in a 250 mL serum bottle, and cultured for 24 h at 37°C under different illumination conditions. The results showed that the floc was more sensitive to illumination than the granule. A hydrogen yield of 19.8 mL was obtained in the dark with a specific hydrogen production rate of 3.52 mol·kg-1MLVSS·d-1 (floc), which was the highest among the three illumination conditions. Under dark condition, the hydrogen yield of floc sludge reached the highest with the specific hydrogen production rate of 3.52 mol·kg-1MLVSS·d-1, and under light-dark, light, the specific hydrogen production rate was 3.11 and 2.21 mol·kg-1MLVSS·d-1, respectively. The results demonstrated that the illumination may affect the dehydrogenase activity of sludge as well as the activity of hydrogen-producing acetogens and then impact hydrogen production capacity. 相似文献
50.