本文關(guān)鍵詞：重慶南川巖溶區(qū)不同土地利用類型下碳運(yùn)移特征及其影響因素　出處：《西南大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 土地利用類型 巖溶泉 土壤CO_2 脫水和脫氣作用 碳同位素

【摘要】：隨著全球氣候變暖以及極端氣候事件的頻頻發(fā)生,碳循環(huán)逐漸受到人們的重視。碳酸鹽巖作為全球最大的碳庫(kù),其對(duì)全球碳循環(huán)的重要性不言而喻。碳酸鹽巖通過巖溶作用消耗大氣或土壤CO_2,對(duì)大氣起到減源增匯的作用。受上覆植被類型、土壤理化性質(zhì)、耕作方式以及HNO3和H2SO4等強(qiáng)酸影響,不同土地利用類型下的土壤CO_2濃度及巖溶碳循環(huán)具有明顯差異。為此,弄清巖溶區(qū)不同土地利用類型下碳運(yùn)移特征及其影響因素,有助于準(zhǔn)確估算巖溶碳匯效應(yīng),并為改善土地利用方式以增強(qiáng)巖溶碳匯效應(yīng)提供理論依據(jù)。本文以重慶市南川區(qū)柏樹灣泉域、蘭花溝泉域和后溝泉域?yàn)槔?通過監(jiān)測(cè)巖溶泉水化學(xué)性質(zhì),探討不同土地利用類型下巖溶碳循環(huán)的差異。另外,本文通過研究3個(gè)泉域上覆土壤理化性質(zhì)、植被類型以及土壤CO_2,并運(yùn)用穩(wěn)定碳同位素對(duì)碳在各圈層的運(yùn)移進(jìn)行示蹤,揭示不同土地利用類型下碳運(yùn)移特征及其影響因素的差異。3個(gè)巖溶泉中的陽(yáng)離子均以Ca~(2+)為主,但陰離子組成具有明顯差異。柏樹灣泉域受人類活動(dòng)干擾小,陰離子主要以HCO3-為主,泉水為HCO3-Ca型。蘭花溝泉域和后溝泉域受氮肥及煤鐵殘?jiān)纫蛩赜绊?NO3-和SO42-的含量增加,泉水屬于HCO3·SO4-Ca型。通過水化學(xué)性質(zhì)計(jì)算出了3個(gè)泉域的巖溶碳匯效應(yīng)。在不同土地利用類型下,巖溶作用對(duì)土壤CO_2的凈消耗量具有明顯差異,柏樹灣泉域巖溶作用對(duì)土壤CO_2的凈消耗量最大,后溝泉域最小,蘭花溝泉域居中。在不同季節(jié),巖溶作用對(duì)土壤CO_2的凈消耗量也會(huì)發(fā)生變化。其中柏樹灣泉域土壤CO_2凈消耗量由旱季的2.17 mmol·L-1增加到雨季的2.31 mmol·L-1;蘭花溝泉域和后溝泉域土壤CO_2的凈消耗量則分別由旱季的0.58 mmol·L-1、-0.15 mmol·L-1下降到雨季的0.27mmol·L-1、-0.27mmol·L-1。3個(gè)泉域土壤CO_2濃度具有明顯的季節(jié)變化特征,即雨季土壤CO_2濃度明顯大于旱季。蘭花溝泉域和后溝泉域土壤CO_2濃度與土壤溫度呈正相關(guān)關(guān)系(0.05P0.1),雨季土壤溫度升高促進(jìn)了土壤CO_2的產(chǎn)生,但土-氣之間的CO_2通量也隨溫度升高而增加,導(dǎo)致蘭花溝和后溝泉域巖溶作用對(duì)土壤CO_2的凈消耗量在雨季并沒有增加。不同土地利用類型下土壤CO_2濃度也存在明顯差異:無論雨季還是旱季,柏樹灣泉域土壤CO_2濃度均大于蘭花溝和后溝泉域;旱季蘭花溝泉域土壤CO_2濃度小于后溝泉域,而雨季蘭花溝泉域20cm和50cm處土壤CO_2濃度大于后溝泉域。在土壤CO_2濃度的垂向變化上,柏樹灣泉域土壤CO_2濃度在雨季和旱季均出現(xiàn)雙向梯度;蘭花溝泉域土壤較薄,土壤CO_2濃度隨土壤深度的增加而增加;后溝泉域土壤CO_2濃度在旱季表現(xiàn)為雙向梯度,在雨季則隨土壤深度增加而增加。上覆植被以及土壤性質(zhì)是導(dǎo)致不同土地利用類型下土壤CO_2濃度變化特征出現(xiàn)差異的主要原因。柏樹灣泉巖溶作用對(duì)土壤CO_2的凈消耗量最大且雨季大于旱季,與土壤CO_2濃度的變化一致。但蘭花溝和后溝CO_2凈消耗量卻與土壤CO_2濃度變化趨勢(shì)相反,并且無論蘭花溝泉域土壤CO_2濃度是否大于后溝泉域,其土下巖溶作用對(duì)土壤CO_2的凈消耗量均大于后溝泉域。這說明土壤CO_2濃度并不是影響蘭花溝和后溝泉域土下巖溶作用的主要因素。在不同的土地利用類型下,受土壤性質(zhì)及人類活動(dòng)等影響,碳運(yùn)移特征及其影響因素也會(huì)出現(xiàn)差異。室內(nèi)模擬實(shí)驗(yàn)中設(shè)計(jì)了6個(gè)不同的處理,以分析不同因素對(duì)土下巖溶作用及碳運(yùn)移特征的影響。實(shí)驗(yàn)結(jié)果表明,H2SO4含量增加導(dǎo)致土下巖溶作用增強(qiáng),但巖溶作用對(duì)CO_2的凈消耗量并沒有隨之增加。并且當(dāng)H2SO4溶蝕碳酸鹽巖產(chǎn)生CO_2沒有再次參與巖溶作用時(shí),巖溶作用對(duì)CO_2的凈消耗量隨H2SO4含量的增加而減少;降水對(duì)下滲水的水化學(xué)性質(zhì)產(chǎn)生了明顯的稀釋效應(yīng),即降水量增加導(dǎo)致下滲水中各離子濃度減小;土壤厚度既可以通過土壤CO_2又可以通過土壤中H2SO4含量間接影響土下巖溶作用強(qiáng)度及碳在各圈層中的運(yùn)移方向。通過監(jiān)測(cè)土壤CO_2的δ~(13)C以及泉水δ~(13)CDIC發(fā)現(xiàn),雨季植物殘?bào)w以DOC的形式進(jìn)入底部土壤也是引起底部土壤CO_2δ~(13)C變化的重要原因,因此僅僅依靠土壤CO_2的δ~(13)C并不能判斷HNO3和H2SO4溶蝕碳酸鹽巖后產(chǎn)生的CO_2是否返回到土壤中。蘭花溝泉和后溝泉水化學(xué)性質(zhì)及泉水δ~(13)CDIC顯示,HNO3和H2SO4溶蝕碳酸鹽巖后產(chǎn)生的CO_2并沒有全部再次對(duì)碳酸鹽巖進(jìn)行溶蝕。在降水減少的時(shí)期,土壤CO_2因水巖接觸時(shí)間增加,其對(duì)碳酸鹽巖溶蝕量的貢獻(xiàn)增加。但HNO3和H2SO4溶蝕碳酸鹽巖后產(chǎn)生的CO_2對(duì)碳酸鹽巖的溶蝕作用也隨之加強(qiáng),這意味著更多來自碳酸鹽巖的碳進(jìn)入到水體中。另外,由于表層土壤呈酸性,在土壤水下滲速率減慢時(shí),更多的H+與HCO3-結(jié)合,較輕的碳從水體中脫離,從而導(dǎo)致巖溶泉水δ~(13)CDIC偏重。以上作用共同控制泉水δ~(13)CDIC,導(dǎo)致泉水δ~(13)CDIC不能反映出巖溶碳匯效應(yīng)的變化。以上結(jié)果表明,受上覆植被類型、土壤性質(zhì)及人類活動(dòng)影響,本研究中林地巖溶作用對(duì)土壤CO_2的凈消耗量主要受土壤CO_2濃度控制;而在農(nóng)用地,巖溶作用對(duì)土壤CO_2的凈消耗量主要受降水控制。另外,運(yùn)用碳同位素技術(shù)估算巖溶碳匯效應(yīng)時(shí),HNO3和H2SO4溶蝕碳酸鹽巖后產(chǎn)生的CO_2脫離水體可能會(huì)導(dǎo)致計(jì)算結(jié)果出現(xiàn)偏差。因此在研究巖溶碳匯效應(yīng)時(shí),需考慮此部分CO_2運(yùn)移方向?qū)ζ洚a(chǎn)生的影響。
[Abstract]:With the global climate warming and the frequent occurrence of extreme weather events, the carbon cycle has attracted more and more attention. Carbonate rocks as the world's largest carbon pool, its importance to the global carbon cycle. The role of Yan Rong self-evident carbonate consumption atmosphere or soil CO_2, reducing the source sink effect on gas. By over the vegetation types, soil physicochemical properties, tillage and HNO3 and H2SO4 acid, under different land use types on soil CO_2 concentration and Yan Rong carbon cycle has a significant difference. Therefore, clarify the different Yan Rong land use characteristics and influence factors of carbon migration type, contribute to the accurate estimation of the carbon sink effect and to improve the Yan Rong. Land use patterns to enhance the carbon sink effect and provide a theoretical basis for Yan Rong. In this paper, Nanchuan District of Chongqing cypress Bay springs, spring area and orchids ditch ditch spring area as an example, through the monitoring of Yan Rong Water chemical properties of different land use types of karst carbon cycle difference. In addition, through the study of the 3 spring area of overlying soil physicochemical properties, vegetation types and soil CO_2, and the use of stable carbon isotope of carbon tracer migration in other spheres, reveal the different land use factors between karst.3 cation the spring migration characteristics and influence types of carbon were Ca~ (2+), but the anion composition has a significant difference. The cypress Bay spring area disturbed by human activities, the anion is dominated by HCO3-, HCO3-Ca. Spring orchids ditch spring area and gully spring area affected by nitrogen and iron and coal residue etc., increase the content of NO3- and SO42-, HCO3 and SO4-Ca belong to the spring type. The chemical properties of water through calculating the 3 spring area. The karst carbon sink effect under different land use types, karst measuring net consumption of soil CO_2 There are obvious differences, the cypress Cove karst effect net consumption of soil CO_2, after the ditch spring area minimum, orchid spring field ditch center. In different seasons, karst net consumption of soil CO_2 will change. The cypress Cove spring area soil CO_2 net consumption increased by 2.17 during the dry season mmol - L-1 2.31 mmol - L-1 to the rainy season; consumption ditch spring area soil CO_2 orchid spring ditch domain and dry season respectively by 0.58 mmol - L-1, -0.15 mmol L-1 0.27mmol L-1 down to the rainy season, with obvious variation -0.27mmol L-1.3 spring field soil CO_2 concentration that is the rainy season, the soil CO_2 concentration was significantly higher than the dry season. The orchid spring area and after the ditch ditch spring area soil CO_2 concentration was positively correlated with soil temperature (0.05P0.1), the relationship between the soil temperature promote the soil CO_2, but the CO_2 flux of soil air are increased with temperature increasing Plus, lead orchid ditch and ditch karst effect net consumption of soil CO_2 in the rainy season did not increase. Under different land use types of soil CO_2 concentration varied significantly: no matter in rainy season or dry season, cypress Bay spring area soil CO_2 concentration were higher than after the ditch ditch and orchid spring area; dry season orchid spring ditch the domain of soil CO_2 concentration is less than the channel after spring area, and the rainy season spring orchids ditch domain 20cm and 50cm soil CO_2 concentration is greater than the spring area. After the ditch to changes in soil CO_2 concentration in the vertical, the cypress Cove spring area soil CO_2 concentration showed bidirectional gradient in the rainy season and the dry season; orchid thin ditch spring area soil, increase the soil CO_2 concentration with soil depth increased; after the ditch spring field soil CO_2 concentration in dry season showed bidirectional gradient, in the rainy season increased with soil depth. The overlying vegetation and soil properties in different land use types of soil CO_2 The concentration variation of the main reasons for the differences. Cypress Bay spring karst net consumption of soil CO_2 maximum and wet season than in dry season, consistent with the change of CO_2 concentration in the soil. But after the ditch ditch and orchid net CO_2 consumption has the opposite trend with soil CO_2 concentration, and whether the orchid spring field ditch soil CO_2 concentration is after more than ditch spring area, the karst soil net consumption of soil CO_2 was greater than the ditch spring area. It indicated that the soil CO_2 concentration is not the main factor influencing the karst spring area and orchids ditch ditch under the soil. In different land use types, affected by soil properties and human activities so, characteristics and influence factors of carbon migration will be different. The experiment designed 6 different treatment of indoor simulation, in order to analyze the influence of different factors on soil under karstification and carbon migration characteristics. Experimental results show that the content of H2SO4 Increase the amount of lead to enhanced karst soil, but the karst net consumption of CO_2 volume was not increased. And when the dissolution of carbonate rocks H2SO4 CO_2 did not participate in the karst again, increasing karst net consumption of CO_2 with the content of H2SO4 decreased; water chemistry of precipitation produced under seepage the dilution effect is obvious, which leads to increased precipitation infiltration of each ion concentration in water decreased; soil thickness can by soil CO_2 can also be affected indirectly through the migration direction of karst soil and carbon intensity in all spheres of H2SO4 content in the soil. By monitoring soil CO_2 8 ~ (13) C and ~ Delta spring CDIC (13) found that the rainy season plant residues into the bottom of the soil in the form of DOC is caused by the bottom soil CO_2 8 ~ (13) C an important reason for change, therefore only rely on soil CO_2 8 ~ (13) C and HNO3 and H2SO can not judge 4 CO_2 after the dissolution of carbonate rocks is returned to the soil. The orchid spring and spring ditch ditch water chemical properties and ~ (13) CDIC Delta, HNO3 and H2SO4 CO_2 after the dissolution of carbonate rocks and carbonate rocks are not all again on the dissolution. The reducing precipitation period, soil CO_2 increased by water rock contact time, its contribution to the increase of the amount of carbonate dissolution. But the dissolution of HNO3 and H2SO4 CO_2 after the dissolution of carbonate rocks in carbonate rocks has been strengthened, which means more from carbonate carbon into the water. In addition, the surface soil is acidic, the soil water infiltration rate slow down, H+ and HCO3- more with the lighter carbon from the water, resulting in karst spring 8 ~ (13) CDIC on the above interaction control spring. 8 ~ (13) CDIC, ~ (13) Delta resulting in spring CDIC cannot reflect the karst carbon sink effect Change. The above results showed that the vegetation types, soil properties and human activities, the role of Forest karst in this study net consumption of soil CO_2 was mainly affected by soil CO_2 concentration control; while in farmland, karst net consumption of soil CO_2 was mainly affected by water control. In addition, the estimation of karst carbon sink the effect of using carbon isotope techniques, the production of HNO3 and H2SO4 CO_2 after the dissolution of carbonate rocks from the water may cause the deviation of calculation results. Therefore research on Karst carbon sink effect, need to consider the effect of this portion of the CO_2 on the migration direction of production.

【學(xué)位授予單位】：西南大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：S151.9

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 劉文;張強(qiáng);賈亞男;;氣象要素及土壤理化性質(zhì)對(duì)不同土地利用方式下冬夏巖溶作用的影響[J];生態(tài)學(xué)報(bào);2014年06期

2 程建中;李心清;周志紅;王兵;程紅光;邢英;唐源;;土壤CO_2濃度與地表CO_2通量的季節(jié)變化及其相互關(guān)系[J];地球與環(huán)境;2011年02期

3 陳麗;姜惠武;張紅光;;植物根系分泌物的研究進(jìn)展[J];林業(yè)勘查設(shè)計(jì);2009年03期

4 劉鵬;金婷婷;徐根娣;胡麗芬;;大豆根系分泌物對(duì)根際土壤鋁形態(tài)的影響[J];浙江師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2008年04期

5 連賓;陳燁;朱立軍;楊瑞東;;微生物對(duì)碳酸鹽巖的風(fēng)化作用[J];地學(xué)前緣;2008年06期

6 李志安,鄒碧,丁永禎,曹裕松;森林凋落物分解重要影響因子及其研究進(jìn)展[J];生態(tài)學(xué)雜志;2004年06期

7 代靜玉,周江敏,秦淑平;幾種有機(jī)物料分解過程中溶解性有機(jī)物質(zhì)化學(xué)成分的變化[J];土壤通報(bào);2004年06期

8 王國(guó)梁,劉國(guó)彬,周生路;黃土丘陵溝壑區(qū)小流域植被恢復(fù)對(duì)土壤穩(wěn)定入滲的影響[J];自然資源學(xué)報(bào);2003年05期

9 薛立,鄺立剛,陳紅躍,譚紹滿;不同林分土壤養(yǎng)分、微生物與酶活性的研究[J];土壤學(xué)報(bào);2003年02期

10 李凌浩,王其兵,白永飛,周廣勝,邢雪榮;錫林河流域羊草草原群落土壤呼吸及其影響因子的研究[J];植物生態(tài)學(xué)報(bào);2000年06期

相關(guān)博士學(xué)位論文 前1條

1 李卓;土壤機(jī)械組成及容重對(duì)水分特征參數(shù)影響模擬試驗(yàn)研究[D];西北農(nóng)林科技大學(xué);2009年

，

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