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1.
[目的] 基于碳排放和碳吸收双重视角来探究农业碳收支时空差异和碳补偿潜力,为湖南省农业全面绿色转型和协调发展提供理论参考。[方法] 采用探索性空间数据分析、绝对β收敛、参数对比法和GIS空间分析方法,对湖南省县域农业碳收支时空差异、碳补偿率空间相关性及收敛性特征、农业碳补偿潜力区域差异进行实证分析。[结果] 湖南省县域农业碳排量整体呈“以高值区为中心,向外围逐渐降低”的结构且农田土壤碳排量是其主要来源,县域农业碳排强度呈“西南高,东北低”且逐年显著降低;县域农业碳汇量整体呈“东中北部高,西南部低”的空间格局且其农业碳汇能力渐趋增强。稻谷对农业碳汇量贡献最大,农业碳吸收强度显著提升且其空间格局发生明显转变。县域农业碳补偿率表现为净碳源,存在显著的空间正相关性和收敛性且其空间集聚特征和关联特征均较为明显。县域农业碳补偿潜力在空间上呈现显著不平衡特征,中、高碳补偿县域比例达60.66%,表明湖南省县域农业碳补偿率偏低,仍具有很大碳补偿空间。[结论] 应深入强化区域合作,多方共促绿色转型,充分发挥农业碳补偿率热点区辐射带动效应,维持好农业碳补偿能力较强区域优良低碳农业发展情势,重点关注中、高碳补偿潜力区域绿色农业发展趋势,缩减湖南省各县域低碳农业发展差距。 相似文献
2.
[目的]定量测算江西省九江市土地利用碳排放,揭示其时空演变特征,并估算土地利用碳排放风险,为九江市构建绿色低碳土地利用方式提供科学参考。[方法]采用土地利用碳排放系数法测度2000—2020年九江市土地利用碳排放和时空变化规律,并从网格化的视角,利用碳排放风险指数识别各县区碳排放风险,基于对数平均迪式指数(LMDI)模型,分析土地利用碳排放的影响因素。[结果] 2000—2020年九江市土地利用净碳排放量呈递增趋势,年均增幅为13.75%,建设用地是主要碳源,占碳排放量的90%以上,林地是主要碳汇。九江市净碳排放量呈现“东北高,西南低”的空间分布特征,森林覆盖率好的武宁县、修水县一直处于碳汇功能,濂溪区、浔阳区、湖口县、瑞昌市的碳排放量占九江市净碳排放量的95%以上。九江市土地利用碳排放风险整体偏低,并呈现“东北高,西南低”的分布特征,长江沿岸县区濂溪区、浔阳区和柴桑区处于高度碳排放风险区。经济发展水平是碳排放增加的主要因素,能源消费强度则是抑制碳排放的关键因素。[结论] 2000—2020年九江市土地利用碳排放大幅增加,应控制新增碳源用地,优化土地利用结构,并积极探索低碳绿色能源利用... 相似文献
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[目的] 研究土地利用碳平衡与人类活动强度间的协同关系,为沱江流域的区域协同碳减排规划及实现中国“碳达峰、碳中和”目标提供参考。[方法] 基于2000—2020年土地利用及社会经济数据,使用碳排放经济贡献系数、碳生态承载系数、人类活动强度指标,耦合协调度模型及回归分析方法,核算了沱江流域土地利用碳排放量并分析了土地利用碳平衡与人类活动强度的时空演变特征及其协同关系。[结果] 研究表明,2000—2020年沱江流域碳排放量增加了5.13×107 t,其中建设用地碳排放量占90%以上;碳吸收量变化不大,主要来自林地,呈现先减后增的趋势;净碳排放增长率呈下降趋势。各区县的土地利用碳平衡协调度均在提升,但70%以上的区域处于失调衰退状态。沱江流域人类活动强度整体处于中等强度水平,空间上从北向南呈现“低—高—低—高”的格局。[结论] 人类活动强度与人均GDP、人均碳排放均存在显著的正相关关系。土地利用碳平衡协调度与人类活动强度的负相关关系随着技术进步与能源利用效率的提高而降低。提高碳汇能力与碳生产力是改善区域土地利用碳平衡协调水平的有效途径。 相似文献
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[目的]揭示县域碳排放的时空格局演变及其驱动因素,为区域规划战略的实际应用和实现“双碳”目标提供科学依据。[方法]基于广西壮族自治区东融发展片区2005,2010,2015,2020年碳排放数据,运用空间自相关分析测算各区域之间的碳排放时空异质性特征,并在构建指标体系的基础上,运用地理探测器计算碳排放时空演变的驱动因子。[结果](1)广西东融片区各县区碳排放量在空间上存在异质性。2005—2020年,该区碳排放量在空间上呈现“西南高,东北低”,经济发达的区县碳排放量增速快;(2)各区县碳排放量在总体上呈现稳步上涨的趋势。不同经济发展水平的区县间碳排放量差距逐渐拉大;(3)在碳排放时空分异驱动力分析方面,能源消费结构和城市经济密度的影响最强。[结论]广西东融发展片区碳排放时空特征与人类活动密切相关,达成“双碳”目标必须以规范碳排放行为为前提。 相似文献
5.
基于土地利用变化的新疆塔城地区碳排放特征分析 总被引：1，自引：0，他引：1
[目的]分析新疆塔城地区1980—2020年的碳排放变化时空特征及效应,为科学制定区域碳减排措施及低碳调控政策提供依据。[方法]基于1980—2020年土地利用变化数据,计算了塔城地区碳排放量和碳吸收量,并采用碳足迹和碳生态承载力评估了碳排放效应。[结果](1)1980—2020年,塔城地区净碳排放量表现出明显的增加趋势,其中耕地和建设用地的不断扩张是导致塔城地区碳排放量增加的主要诱因,而林地面积的持续减少是造成塔城地区碳吸收量减少的关键因素;(2)在空间分布上,沙湾县和乌苏市是塔城地区的主要碳源区,解释了塔城地区净碳排放的67.20%,和丰县和额敏县解释了塔城地区净碳排放量的20.89%,托里县是塔城地区的主要碳汇区;(3)在碳排放效应方面,2000年前塔城地区绝大多数区域都表现为生态盈余,但2000年后开始出现碳排放的生态赤字。[结论]当前,沙湾县、乌苏市及和丰县,存在明显的生态赤字,是未来塔城地区碳减排的重点控制区域。 相似文献
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[目的]对河南省碳排放及碳足迹峰值进行了预测,旨在了解河南省未来碳减排潜力,寻求低碳发展的对策。[方法]基于省域层面,以河南省为例,对历年的碳收支和碳足迹状况进行了核算和评估,并通过STIRPAT模型和情景分析方法对河南省碳排放峰值进行预测。[结果](1)河南省碳排放总量从2000年的6.83×107 t上升到2012年的1.77×108 t,涨幅为159.2%,其中碳排放的行业差异性大,工业占主导地位,不同途径碳排放的增幅具有明显差异,生态系统的碳汇能力呈明显下降趋势。(2)河南省2000—2012年能源消费的碳足迹呈逐年增加态势,从2000年的1.71×107 hm2上升到2012年的4.42×107 hm2。碳足迹的扩大造成了1.68×108 hm2的生态赤字。(3)在基准和低碳情景下,河南省碳排放峰值有望出现在2040和2035年,在考虑区域碳吸收补偿的前提下,碳排放峰值将分别提前到2035和2025年。[结论]河南省碳收支呈现明显的不匹配状态,但在考虑碳补偿的基础上,河南省具有较大的碳减排潜力空间。 相似文献
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[目的] 分析徐州市时空尺度下农业碳排放时空特征与脱钩效应,为江苏省徐州市及其周边资源型城市未来农业的绿色高质可持续发展以及农业经济的良性增长提供理论与数据参考。[方法] 采用排放系数法测算2000—2020年时空尺度下徐州市农业碳排放总量、强度和结构,而后基于Tapio脱钩模型分析其与农业经济发展间的脱钩关系。[结果] ①徐州市农业碳排放变化趋势总体呈“快速上升—波动上升—快速下降”3阶段,从2000年的1.61×106 t先增后减至2020年的1.69×106 t,形象地表现为“M”形。对农业碳排放贡献率大小依次是耕地利用(46.44%)、作物种植(31.90%)和牲畜养殖(21.66%),化肥是最主要碳源。②徐州市各区(县、市)农业碳排放量差异明显,经历了由升到降的长期演化进程,空间层面上总体呈现出“中部高,周边低”的分布格局,邳州市最为突出; ③徐州市农业碳排放与农业经济发展总体经历了“弱脱钩—强负脱钩—扩张负脱钩—强脱钩”的变化历程,且“十三五”以来主要表现为强脱钩。[结论] 徐州市农业碳排放随着低碳减排理念的不断深入而日趋合理,农业经济发展也取得了一定成效。 相似文献
8.
[目的] 探查粮食主产区土地利用变化规律及其碳效应,为土地利用结构调整及低碳经济发展提供依据。[方法] 基于1980,2000,2020年3期土地利用现状数据,在网格采样法、土地利用动态度模型、碳排放系数法以及空间自相关分析模型支持下,揭示1980年以来洞庭湖流域土地利用变化规律及其碳效应的空间异质性特征。[结果] ①洞庭湖流域土地利用阶段性变化。1980—2000年综合动态度为0.02%,其中动态度最大的是建设用地,未利用地次之。2000—2020年综合动态度增至0.18%,建设用地面积增长加快。②净碳效应表现为碳汇,但由1980年的5.93×107 t下降到2020年2.82×107 t,而由土地利用变化引起的碳效应呈现碳排放变化量大于碳汇变化量特点,并导致净碳排放量增加了6.08×105 t,且空间上净碳排放相对高值区呈“H”型分布特点,低值区逐渐扩张。③洞庭湖流域集水小区净碳排放的空间自相关性特征显著。1980—2000年主要聚集类型为高—高型和低—低型,低—高型分布零散,2000—2020年高—高型分布更加集中连片,低—低型主要在湘江流域北部。[结论] 在洞庭湖流域,应坚持“碳增汇,碳减排”定位,保持林地的碳汇稳定状态,科学引导高碳排放土地的开发利用,并依据空间自相关特点关注不同集水区的碳排放“同化”作用。 相似文献
9.
[目的] 探究广东省农田生态系统碳源汇效应时空分异及驱动因素,为广东省科学合理制定区域农业减排固碳措施提供参考。[方法] 采用参数估计法、GIS空间分析等方法定量评估2010—2020年广东省农田生态系统碳源汇效应时空演变规律,并借助LMDI因素分解模型探究农田生态系统碳源汇效应空间分异的驱动因素。[结果] ①广东省农田生态系统碳源汇效应水平维持持续向好发展态势,减排增汇效应逐渐凸显。具体表现为：固碳总量呈波动上升态势,稻谷、甘蔗、蔬菜为主要的碳汇作物;碳排放得到有效控制,减排效应日益显现,稻田种植、农资投入为主要的碳源类型;农田生态系统固碳量增长有效抵消了碳排放增长。②广东省农田生态系统碳源汇效应空间分异明显,总体呈相对集聚分布态势,湛江为主要的高碳源—高碳汇地区,低碳源—低碳汇则主要分布在珠三角地区。③经济因素为农田生态系统碳汇提升的关键驱动因素,结构因素表现出两面性且因地而异,效率因素、劳动力因素则表现为抑制作用。[结论] 广东省农田生态系统碳源汇效应水平稳中向好,但区域分异明显,应结合各地经济、结构、效率、劳动力等因素的驱动效应差异,因地制宜制定农业减排固碳措施。 相似文献
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[目的] 开展土地利用碳排放差异与碳补偿研究，为各地域根据净碳排放量制定低碳发展政策提供依据。[方法] 基于2005—2020年福建省土地利用和能源消费数据，构建碳排放以及碳补偿价值测算模型，计算各市域不同时段的碳排放量以及碳补偿价值。[结果] ①福建省土地利用变化净碳排放呈现出明显的增长趋势，增长速度先快后慢。建设用地为主要碳源，其碳排放量增加3.41×107 t；林地为主要碳汇，其碳吸收量减少近3.00×104 t。②净碳排放量高值区域主要分布在碳排放量高、碳补偿率低的福州市、泉州市和漳州市，净碳排放量低值区域主要分布在碳排放量少、碳补偿率高的南平市，除厦门市外，各市的净碳排放强度与净碳排放量的空间分布相似。③碳补偿价值与各市净碳排放量的空间分布具有高度相似性，高碳补偿区主要是经济发展水平高、净碳排放量大的福州市、泉州市，受偿区主要是经济发展水平低、净碳排放量小的南平市。[结论] 为实现区域协调以及低碳发展，需不断完善碳补偿机制，从低碳层面依靠碳补偿推动区域低碳协调发展。 相似文献
11.
Appropriate compost standards are being considered in Canada. Five aspects of compost safety and quality are being evaluated; probably the most controversial aspect is the standards for metals in compost. In order to assist in the development of appropriate standards, the authors began an extensive research project in October, 1993 to determine the bioavailability of metals from compost and compost-metal mixtures. Swiss chard was grown in compost-amended soils or compost in a growth room using five treatments of increasing percentages of compost in the media (0, 25 percent, 50 percent, 75 percent, 100 percent compost (v/v)). A Truro loamy sand and a race-track manure-biosolids compost (RTM-biosolids) supplemented with a high metal biosolids were used in a completely randomized design with five replicates. Dry matter yield, metal content in plant tissue, and total metal uptake were evaluated as well as the total and DTPA-extractable metal content in the compost-soil mixes. The results of this and five other experiments conducted by the authors will help determine whether the suggested limits for As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se and Zn in composts are appropriate. 相似文献
12.
《Communications in Soil Science and Plant Analysis》2012,43(4):291-301
Abstract The seasonal patterns of foliage nutrient concentrations and contents were monitored for two growing seasons in an 11‐year—old Pinus el1iottii stand. In the first growing season after needle initiation, N, P, K, Mg, and Zn concentrations decreased, but this was followed by an increase in the fall and winter months. Another drop in concentration of all elements, except P, occurred in the second growing season. Decreases in total contents indicated that this drop was a result of translocation to other tissues. In contrast to the mobile elements, the concentration and fascicle contents of Ca, Mn, and Al increased with aging of the needles. Between‐tree variability was least for N, P, and Zn and the N, K, Mg, Mn, and Zn in the current foliage had consistently lower variation than that in the 1‐year‐old foliage. Between‐tree variation for K was lower in the winter than the spring. For pine foliage, recommended sampling period for N, P, Mg, and Zn is mid to late summer and for the other elements it is late fall to late winter. There are several sources of variation that influence the level of nutrients in tree foliage. The most important of these, apart from the tree nutrient status, are seasonal fluctuations, variation between trees, and age of needles . Smaller sources of variation are associated with position of the needles within the crown, diurnal changes, year to year variation, and analytical errors1,2. These variables must be studied in order to develop suitable sampling techniques and in Pinus this has been undertaken for P. banksiana 1, P. taeda 3, P. strobus 4, P. resinosa 4, P. sylvestris 5, and P. radiata 6,7. However, foliage sampling has not been studied in detail for slash pine (Pinus elliottii Englem var. elliottii) and earlier studies with other pines have been largely confined to temperate or cool climates. This study reports the variation in elemental concentrations with season, age of foliage, and between slash pine trees growing in a subtropical climate in Florida. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(9):751-756
Abstract The phytotoxicity of five nonessential elements (Co, V, Ti, Ag, Cr) to higher plants was studied in solution culture experiments with bush beans (Phaseolus vulgaris L. C.V. Improved Tendergreen). All, but in varying degrees, tended to concentrate in roots with a decreasing gradient to stems and leaves. Cobalt was one of the more mobile of the five trace metals. Its toxicity was expressed as severe chlorosis; 43 (with 10‐5 M) and 142 (with 10‐4 M) μg Co/g dry weight in leaves resulted in severe chlorosis. Vanadium as 10‐4 M vanadate resulted in smaller plants but not in chlorosis. Leaf, stem, and root V, respectively, were 13, 8, and 881 μg/g dry weight. Titanium was somewhat mobile with considerable yield decrease at 10‐4 M; leaf, stem, and root Ti concentrations, respectively, were 202, 48, and 2420 μg/g. Symptoms were chlorosis, necrotic spots on leaves, and stunting. Silver was very lethal at 10‐4 M AgNO3; at 10‐5 M yields were greatly decreased, but plants were grown without symptoms. Leaf, stem, and root concentrations of Ag for this treatment, respectively, were 5.8, 5.1, and 1760 μg/g dry weight. Plants grown with 10‐5 N Cr2O7 were decreased in yield by about 25% with or without EDTA (ethylenediamine tetraacetic acid) while the same level of Cr2(SO4)3 was essentially without effect. For the two salts, the leaf, stem, root concentrations for Cr, respectively were 2.2 and 1.3, 0.7 and 0. 7, and 140 and 104 μg/g. Most of the trace metals studied here had interactions in the uptake and/or distribution of other elements. 相似文献
15.
A Gimeno 《Journal of the Association of Official Analytical Chemists》1979,62(3):579-585
A general method is described for determining 16 mycotoxins in mixed feeds and other food products used in the manufacture of these feedstuffs. The mycotoxins are extracted and cleaned up by extracting with solvents of different pH. Thin layer chromatography is used to separate the toxins; toxins are then quantitated by the limit detection method. The minimum detectable concentration of mycotoxins in various products is: aflatoxin B1 or G1, 4--5 micrograms/kg; ochratoxin A or ethyl ester A 140--145 micrograms/kg; citrinin 600--750 micrograms/kg; zearalenone, 410--500 micrograms/kg; sterigmatocystin, 140--145 micrograms/kg; diacetoxyscirpenol, 2400--2600 micrograms/kg; T-2 toxin, 800--950 micrograms/kg; patulin, 750--800 micrograms/kg; penitrem A 14,000--14,500 micrograms/kg; penicillic acid 3400--3650 micrograms/kg. 相似文献
16.
B S Kaphalia R Takroo S Mehrotra U Nigam T D Seth 《Journal of the Association of Official Analytical Chemists》1990,73(4):509-512
A total of 244 samples of cereals (wheat flour, rice, and maize), pulses (arhar, moong, gram, lentil, and black gram), spices (turmeric, chili, coriander, and black pepper), vegetables (potato, onion, spinach, cabbage, brinjal, and tomato), fruits (mango, guava, apple, and grape), milk, butter, Deshi ghee, and edible oils (vegetable, mustard, groundnut, and sesame) collected from different cities of Northern Province (Utter Pradesh) were analyzed by gas liquid chromatography for the presence of organochlorine pesticide residues. Residues of hexachlorocyclohexane (HCH) and 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) were detected in about 85% of the total samples of cereals, spices, milk, butter, Deshi ghee, and edible oils analyzed in the present study. However, the residue levels were either very small (less than 0.06 ppm) or not detected at all in pulses, vegetables, and fruits as compared with very high concentrations in wheat flour (4.42 and 0.12 ppm), butter (1.19 and 4.85 ppm), mustard oil (1.26 and 2.42 ppm), Deshi ghee (1.10 and 3.84 ppm), vegetable oil (1.02 and 0.59 ppm), groundnut oil (0.51 and 1.49 ppm), and chili (0.48 and 1.92 ppm). The levels of HCH and DDT residues detected in rice, maize, turmeric, corlander, black pepper, and all the vegetables and fruits were also lower than those found in wheat flour, oil, and fat samples analyzed in the present study. These findings suggest that a restricted and controlled use of such persistent pesticides may be useful for decreasing their contamination levels in different food items. 相似文献
17.
《Communications in Soil Science and Plant Analysis》2012,43(7-8):945-959
Abstract The objectives of this study were 1) to recommend reference values (RVs) and tolerance limits (TLs) for representative Brazilian soils and 2) to propose a model to calculate natural contents of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in a soil from the silt, clay, manganese (Mn), iron (Fe), and cation exchange capacity (CEC) values. A set of 256 soil samples was classified by similarity in seven groups, and the concentrations corresponding to the upper quarter of data collected were then calculated. These concentrations are proposed as RVs for Brazilian soils. Additionally, TLs were obtained for each group from the antilog expression (m+2s), where m=mean value and s=standard deviation of data transformed in log10. The classification functions of discriminant analysis proved to be suitable to allocate new samples in the established groups. Thus, it is possible to evaluate soils under anthropic activity and, by comparison with reference values, to be aware of pollution risks in a given area. 相似文献
18.
《Communications in Soil Science and Plant Analysis》2012,43(19):2495-2501
Different procedures have been proposed to decompose soil samples. Most of them regard determination with fertility aims. In this case, the contents available to the plants are considered. On the other hand, there are procedures to determine total content. The objective of this work was to propose a new decomposition procedure to determine barium (Ba), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), vanadium (V), and zinc (Zn) total content in tropical soils with high content of oxides and silicate. According to the results, the digestion procedure proposed in this study provided satisfactory results for the contents recovery for the elements Ba, Co, Cr, Cu, Mn, Ni, V, and Zn, above 90%, and the use of inverted aqua regia, hydrogen peroxide (H2O2), hydrofluoric acid (HF), pre-digestions and agitation was shown as a new alternative for the high silicate content soil sample total digestion, such as the oxisols. 相似文献
19.
Nigel J.H. Smith 《Biological conservation》1981,19(3):177-187
Amazonia, the world's largest tropical rain forest, is often assumed to be a virtually untouched wilderness. The region is often referred to as a demographic void; there is on average only about one person per sq. km. Yet in response to international market forces, the hand of man has penetrated deep into the imposing forests. Since colonial times, wildlife, particularly along rivers, has been exploited on a large-scale basis for commercial purposes. This paper focuses on the effects of the trade on some aquatic animals. 相似文献
20.
Rababah TM Hettiarachchy NS Horax R 《Journal of agricultural and food chemistry》2004,52(16):5183-5186
The total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone, were determined. Grape seed and green tea were analyzed for their phenolic constituents using high-performance liquid chromatography. The total phenolics of the plant extracts, determined by the Folin-Ciocalteu method, ranged from 24.8 to 92.5 mg of chlorogenic acid equivalent/g dry material. The antioxidant activities of methanolic extracts determined by conjugated diene measurement of methyl linoleate were 3.4-86.3%. The antioxidant activity of the extracts using chicken fat by an oxidative stability instrument (4.6-10.2 h of induction time) followed a similar trend in antioxidant activity as determined by the Folin-Ciocalteu method. Seven phenolics in grape seed and green tea extracts were identified that ranged from 15.38 to 1158.49 and 18.3 to 1087.02 mg/100 g of extract, respectively. Plant extracts such as green tea and grape seed extracts can be used to retard lipid oxidation in a variety of food products. 相似文献