曹建华1 2潘根兴2袁道先1姜光芒1
1中国质科学院岩溶质研究国土资源部岩溶动力学重点实验室广西 桂林 5410042南京农业学资源环境学院江苏 南京 210095
摘:桂林岩溶试验场土壤溶解机碳〔DOC〕进行逐月观测结果显示DOC岩溶生态系统中活泼机碳组分岩溶区碳循环中发挥着重作年中土壤DOC变化特征表现3阶段:〔1〕3~7月气温升高降雨量增加土壤生物活性新陈代谢力极提高土壤溶解机碳呈升高趋势〔2〕8~11月气温保持较高水降雨量偏低土壤枯燥土壤微生物活性极减弱土壤DOC质量分数全年低〔3〕12月次年2月温度降低土壤生物活性逐渐降低土壤DOC呈缓慢升高趋势土壤微生物量碳间存互消长关系土壤碳酸盐岩溶蚀速率季节变化土壤DOC间存负相关文章提出岩溶区土壤碳循环模式DOC中作
关键词:土壤溶解机碳岩溶作碳循环桂林
中图分类号:X14 文献标识码:A 文章编号:16722175〔2005〕02022406
土壤溶解机碳〔DOC〕陆生态系统中碳迁移研究中热点[1~3]CO2研究样溶解机碳已渗透全球碳循环研究领域:Joan D W 等[4]研究雨水中溶解机碳浓度动态浓度海洋陆空雨水分23 μmolL161 μmolL雨水中硝酸硫酸高Aitkenhead J A等[5]通164条陆流海洋河流研究揭示陆海洋排泄机碳中机碳〔HCO3〕占60机碳占40溶解机碳形式存碳约占22〔36×1014 ga〕相missing carbon〞13溶解机碳活泼性陆生态程中作研究具重理意义
全球碳酸盐岩分布面积2200万km2约占陆面积15[67]碳酸盐岩作物质根底岩溶生态系统陆生态系统重组成局部[8 9]全球岩溶作年回收气CO2碳量608×1014 g [10]碳酸盐岩溶性土壤环境中活泼CO2溶解机碳岩溶作密切相关[11]文桂林岩溶试验场例探索土壤溶解机碳季节动态特征分析土壤溶解机碳岩溶环境中作
1 材料方法
11 野外研究点概况
桂林岩溶试验场位桂林东南8 km处丫吉村附处桂林典型峰丛洼峰林原交界带2 km2峰丛洼系统构成场区峰丛洼岩溶层泥盆统融县组〔D3r〕岩石成分浅灰色白色致密质纯中厚层泥亮晶颗粒石灰岩区顶峰海拔652 m附峰林原原面标高150 m该区属亚热带季风区年均气温188 ℃降雨量19152 mm降雨分配均匀4~8月总降雨量占全年降雨量7032场区土壤棕色石灰土山体部土壤稀薄哑口土壤厚30~50 cmA层机碳质量分数4559 gkg坡土壤较厚达70~150 cmA层机碳质量分数3417 gkg洼中土壤层厚达300~500 cmA层机碳质量分数4580 gkg区土壤覆盖率约30%植覆盖次生灌丛林覆盖度60~80树高2~25 m刺叶革质叶型表现出喜钙耐旱性树种石山樟广西芒林黄荆火棘竹叶椒穿破石云石石岩枫崖棕石山巴豆南天竹水竹杨奶九龙藤桂林紫微苞茅零余薯等
12 监测指标方法
土壤呼吸排放CO2速率:碱吸收法监测土壤呼吸排放CO2速率[12]监测点设哑口
土壤溶解机碳土壤微生物量:0~20 cm20~50 cm取土样冰箱中保鲜土壤微生物量氯仿熏蒸培养提取法[13]土壤溶解机碳TOCV总机碳分析仪[14]
碳酸盐岩溶蚀率:标准圆形石灰岩溶蚀试片置放土20 cm50 cm处监测碳酸盐岩溶蚀速率季度获组数
气温降雨量:利实验场型气象设备监测日气温降雨量
观测周期月1次(碳酸盐岩溶蚀速率3月1次)持续时间1年(2000年3月2001年4月)监测点分哑口坡洼
2 结果
21 土壤溶解机碳季节动态
土壤环境中溶解机碳微生物分解机质代谢产物微生物生长繁殖必需量重源[15]根前研究土壤微生物活性10 ℃温度快增强25~35 ℃间达强[16]外微生物活动土壤湿度关系密切着土水势增加微生物活性减弱001 mP〔相田间持水量〕时微生物活性强[16]水热条件影响土壤微生物活性土壤溶解机碳产生前提土壤溶解机碳奉献中细菌奉献挥发性组分真菌奉献非挥发性组分[17]植物根系新陈代谢强弱分泌物产生少影响土壤溶解机碳动态重素图1桂林岩溶试验场土壤溶解机碳变化三阶段:
微生物量碳(mg·kg1)
图1 土壤溶解机碳动态气温降雨土壤呼吸微生物量碳间关系
Fig 1 Relationship between monthly change of soil DOC and and of temperature rainfall soil respiration and soil microbial biomass carbon
〔1〕3~7月土壤微生物量碳处较低水土壤溶解机碳土壤呼吸排放CO2速率保持着相升高趋势春季初夏次生灌丛林土壤微生物方面足够易分解新鲜机质存方面气温断升高降雨量逐渐增加活性新陈代谢力极提高时适宜水热条件极提高植新陈代谢速率植物根系土壤环境中释放CO2溶解机碳量增加春季初夏降雨土壤机碳土壤CO2较强雨水淋溶淋失作强生物活性高生物代谢产物产生速率浓度土壤环境中保持持续升土壤微生物处活泼新陈代谢状态土壤微生物周转速率提高活性土壤微生物量碳蓄存量降低
〔2〕8~11月气温保持较高水降雨量偏低土壤容易枯燥局部微生物难耐受
土壤枯燥土壤微生物活性极减弱结果土壤呼吸土壤溶解机碳浓度降低里需说明9月27日~10月26日间降雨259 mm刺激微生物量繁殖土壤微生物量碳土壤呼吸速率出现反弹溶解机碳出现全年低值导致现象产生:长时间土壤枯燥降雨雨水淋溶作强微生物代谢产生溶解机碳速率
〔3〕12月次年2月温度降低微生物活性逐渐降低土壤呼吸速率持续降低时溶解机碳升高动态变化程土壤微生物量碳间存互消长关系降雨较少相均匀温度较低微生物活性微弱情况溶解机碳微生物生长繁殖量源时真菌细菌更耐受低温真菌代谢产物真菌尸体分解产生分子溶解机碳条件适宜土壤微生物繁殖时量消耗土壤中溶解机碳条件适宜微生物伤亡时土壤中溶解机碳累积
22 土壤溶解机碳空间变化
野外监测结果显示岩溶洼系统中土壤溶解机碳存空间变化〔图2〕
〔1〕哑口坡洼土壤溶解机碳具相变化趋势反映动态变化水热分配存密切关系
〔2〕貌部位土壤溶解机碳质量分数变化幅度土20 cm例:w〔哑口数值46657563909 mgkg〕>w〔坡数值3870955493316 mgkg〕>w〔洼数值3332349728353 mgkg〕结果反映出土壤溶解机碳环境变化敏感性哑口部位土壤层厚30~50 cm仅坡洼土层厚12110雨水土壤成分淋溶淋失产生较强效应哑口土壤环境中物质迁移强烈标准溶蚀试片结果揭示哑口土碳酸盐岩溶蚀速率高
图2 貌部位土壤层位DOC动态时空分布
Fig 2 Temporal and spatial distribution of soil DOC in different soil layers in different locations
〔3〕全年均值土20 cm土壤溶解机碳质量分数高低次:垭口〔22627 mgkg〕→坡〔22030 mgkg〕→洼〔15231 mgkg〕土50 cm土壤溶解机碳质量分数高低次:坡〔21461 mgkg〕→垭口〔17479 mgkg〕→洼〔15428 mgkg〕考虑土壤环境中DOC动态变化土壤微生物活性气温降雨强度分配规律貌部位土壤水分迁移等条件密切相关更深入机理需进步探索
23 土壤溶解机碳土碳酸盐岩溶蚀关系
表1 桂林岩溶试验场垭口土深度试片溶蚀量影响子关系
Table 1 Dissolution rate under soil on saddle and the impacting factors
日期
溶蚀量mg
均气温℃
降雨量mm
土壤DOC(mg·kg1)
排放速率(mg·h1·m2)
20 cm
50 cm
20 cm
50 cm
4月~6月
7月~9月
10月~12月
1月~3月
全年
1031
295
401
334
2061
1585
726
376
628
3315
230
274
149
115
192
8868
2595
1755
2511
15729
16648
21873
21767
27197
21870
23445
18967
16053
19030
19374
13342
18170
10139
4979
11658
土碳酸盐岩溶蚀土壤环境中侵蚀性组分质量浓度〔CO2机酸螯合物〕变化迁移速率关野外监测结果显示:
〔1〕哑口例4~6月溶蚀量明显季节3季节25~35倍〔表1〕土50 cm处试片溶蚀失重量10~12月略低20cm处外均20 cm处全年总量20 cm处高出6574~6月气温断升高时降雨量渐次增加土50 cm处土20 cm处更修养水分保存土壤生物代谢产物条件
〔2〕结果土溶蚀量降雨量成正相关土壤DOC成负相关气温土壤呼吸间相关明显应该引起注意岩溶动力系统球表层系统中活泼局部运行规律演化程复杂
通述土壤环境中碳循环土壤生物活性强度转移定生态系统土壤生物活性强弱动态变化受温度降雨影响缺
〔3〕峰丛洼系统垭口部位土碳酸盐岩溶蚀量明显高坡洼〔图3〕全年溶蚀量言土20 cm哑口碳酸盐岩溶蚀量〔2061 mg片〕坡〔1006 mg片〕205倍洼〔401 mg片〕514倍土50 cm哑口碳酸盐岩溶蚀量〔3315 mg片〕坡〔1178 mg片〕281倍洼〔293 mg片〕1131倍意味着哑口部位物质量迁移交换迅速岩溶作强烈
图3 桂林岩溶试验场貌部位土壤层位试片溶蚀量
Fig 3 Comparison of dissolution rate at different soil layer in various geomorpholgical locations
3 讨
然条件土壤机碳源植物光合作枯枝落叶根传输分泌程进入土壤土壤环境中碳迁移规模方植物种类土壤类型外取决土壤微生物植物根系活性土壤溶解机碳30年尤10年时间受环境学家生态学家全球变化研究者关注热点指标[18~20]土壤溶解机碳目前操作定义具结构通045 μm滤孔类机物质包括机酸糖氨基酸等化学性质异种化合物混合物[21 22]
土壤溶解机碳源植物枯枝落叶土壤腐殖质微生物伤亡体根分泌物土壤溶解机碳奉献者土壤腐殖质期植物凋落物直法[23 24]植物根际环境较高碳通量强烈微生物活动土壤溶解机碳奉献较统认识活泼根分泌程植物光合化机物5~25传输土壤环境中50~75复杂溶解机化合物形式存[25]土壤溶液中溶解机碳结构组成研究说明微生物代谢产物糖脱氧糖土壤溶解机碳中糖类物质源[26]时Yavitt and Fahey [27]实验结果说明抗生素处理土壤中DOC含量提供10倍DOC身微生物获取生长生存需量直接途径Yano等[28]认森林土壤中约12~40%DOC微生物利微生物量DOC间种产生利关系实际种化发生分解消耗关系次野外研究中12月次年2月土壤微生物量碳土壤DOC质量分数间互消长关系程表现认植物根系分泌产物微生物代谢产物土壤溶解机碳源
土壤溶解机碳土壤固相机碳相具更活性点位[24]强烈影响土壤形成矿物风化污染物质毒性迁移营养物质效性[29~31]时微生物生长生物分解程中重量源[32 33]认土壤碳生物球化学循环中发挥重作土壤溶解机碳组分中分子酸性物质〔≤5碳原子脂肪酸官团酸〕占30~50例[34]岩溶生态系统中具重理意义:〔1〕土壤溶解机碳岩溶作驱动力初步研究结果显示5 mmolL柠檬酸50000×106 CO2碳酸盐岩相侵蚀力[11]〔2〕土壤溶解机碳岩溶区古环境信息载体土壤溶解机碳产生量组成差异运移植物微生物活性生态环境变迁关系密切水运移传输洞穴洞穴沉积物中封存成环境变迁信息载体[35 36]已资料文结果岩溶区土壤碳循环程溶解机碳作纳图4
图4 土壤环境中碳循环程生物作
Fig 4 Map of the biological action in soil carbon cycle
图中(1):伤亡微生物体活微生物源(2):土壤微生物具极短生命周期时存化生长消亡分解(3)(13):微生物枯枝落叶分解产生中间分解产物DOC终极产物CO2(4)(10):微生物土壤机碳分解产生DOCCO2(5):枯枝落叶微生物作合成土壤机碳(6)(14):失活微生物体极易活性微生物利产生量CO2DOC(7):根系呼吸产生CO2(8):植物根土壤微生物互利互惠:根系微生物提供适宜生长环境微生物植物提供效养分(9):DOC活性微生物源(11):植物根分泌产生DOC(12):DOC易受微生物降解产生CO2(15):CO2溶水生成碳酸
参考文献:
[1] KLINKHAMMER G P MCMANUS J COLBERT D et al Behavior of terrestrial dissolved organic matter at the continentocean boundary from highresolution distributions[J] Geochimica et Cosmochemica Acta 2000 64(16) 2765-2774
[2] 曹建华 潘根兴 袁道先 植物凋落物土壤机碳淋失影响岩溶意义[J] 第四纪研究 2000 20(4) 359-366
CAO JIANHUA PAN GENXING YUAN DAOXIAN Influence of two litters on the soil organic carbon leachings and its karst effect[J] Quaternary Sciences 2000 20(4)365-371
[3] PIAO H C HONG Y T YUAN Z Y Seasonal changes of microbass carbon related to climatic factors in soils from karst areas of southwest China[J] Biological Fertilization Soils 2000 30 294-297
[4] JOAN D W ROBERT J K MARY S E et al Rainwater dissolved organic carbon Concentrations and global flux[J] Global Biogeochemical Cycle 2000 14(1)139-148
[5] AITKENHEAD J A MCDOWELL W H Soil C N ratio as a predictor of annual riverine DOC flux at local and global scales[J] Global Biogeochemical Cycle 2000 14(1) 127-138
[6] 王世杰 季宏军 欧阳远 等 碳酸盐岩风化成土初步研究[J] 中国科学(D辑) 1999 29(5) 441-449
WANG SHIJIE JI HONGJUN OUYANG ZHIYUAN et al Preliminary study on carbonate rock weathering and soil formation[J] Science in China(Series D) 1999 29(5) 441-449
[7] 袁道先 现代岩溶学全球变化研究[J] 学前缘 1997 4(1~2) 17-25
YUAN DAOXIAN Modern karstolgy and global change study[J] Earth Science Frontiers 1997 4(1~2) 17-25
[8] 曹建华 袁道先 潘根兴 岩溶动力系统中生物作机制[J] 学前缘 2001 8(1) 203-209
CAO JIANHUA YUAN DAOXIAN PAN GENXING Preliminary study on biological action in karst dynamic system Earth Science Frontiers[J] 2001 8(1) 203-209
[9] 曹建华 袁道先 潘根兴 岩溶生态系统中土壤[J] 球科学进展 2003 18(1) 37-44
CAO JIANHUA YUAN DAOXIAN PAN GENXING Some soil features in karst ecosystem[J] Advance in Earth Sciences 2003 18(1) 37-44
[10] YUAN DAOXIAN The carbon cycle in karst[J] Z Geomorph N F SupplBd 1997 108 91-102
[11] 曹建华 潘根兴 袁道先 柠檬酸碳酸盐岩溶蚀动力模拟岩溶意义[J] 2001 20(1) 1-4
CAO JIANHUA PAN GENXING YUAN DAOXIAN Simulation experiment on dissolution of calcite by citric and its karst importance[J] Carsologica Sinica 2001 20(1)1-4
[12] 佩奇 米勒 土壤分析法[M] 闵九康 郝心仁 严慧峻等译 北京 中国农业科技出版社 1991 536-551
BOISSIER A L MAYER R H Methodology on the soil analysis[M] Translated by MIN JIUKANG HAO XINREN YAN HUIJUN et al Beijing Chinese Agricultural Science and Technology 1991 536-551
[13] VANCE E D BROOKES P C JEKINSON D S An extraction method for measuring soil microbial biomass carbon[J] Soil Biology and Biochemistry 1987 19 703-707
[14] 鲁坤 土壤农业化学分析方法[M] 北京 中国农业科技出版社 1999 24-25
LU RUKUN Analysis on agricultural soil chemistry[M] Beijing Chinese Agricultural Science and Technology 1999 24-25
[15] KALBITZ K SOLINGER S PARK J H et al Controls on the dynamics of dissolved organic matter in soils a review[J] Soil Science 2000 165(4) 277-304
[16] 波尔 克拉克 土壤微生物学生物化学[M] 顾宗濂 李振高 林先贵等译 北京 科学技术文献出版社 1993 13-36
PAUL E A CLARK F E Soil microbiology and biochemistry[M] Translated by GU ZONGLIAN LI ZHENGAO LIN XIANGUI et al Beijing Science and Technology References Press 1993 13-36
[17] 麦克拉伦 波森 斯库舍斯 等 土壤生物化学[M] 闵九康 关松萌 王维敏等译 北京 农业出版社 1984 81-95
MCLAREN A D PETERSON H G SKUJINS J et al Soil biochemistry[M] Translated by MIN JIUKANG GUAN SONGMEN WANG WEIMIN et al Beijing Agricultural Press 1984 81-95
[18] LUDWIG W PROBST JL Predicting the oceanic input of organic carbon by continental erosion[J] Global Biogeochemical Cycles 1996 10(1) 23-41
[19] RAULUNDRASMUSSEN K BORRGGAARD O K HANSEN H C B et al Effect of natural soil solutions on weathering rates of soil minerals[J] Europe Journal of Soil Science 1998 49 397-406
[20] YAMANAKA Y TAJIKA E Role of dissolved organic matter in the marine biogeochemical cycles Studies using an ocean biogeochemical general circulation model[J] Global Biogeochemical cycles 1997 11(4) 599-612
[21] 赵劲松 张旭东 袁星 等 土壤溶解性机质特征环境意义[J] 应生态学报 2003 14(1) 126-130
ZHAO JINSONG ZHANG XUEDONG YUAN XING et al Characteristics and environmental significance of soil dissolved organic matter[J] Chinese Journal of Applied Ecology 2003 14(1)126-130
[22] 李淑芬 余元春 晟 土壤溶解机碳研究进展[J] 土壤环境 2002 11(4) 422-420
LI SHUFEN YU YUANCHUN HE SHENG Summary of research on dissolved organic carbon(DOC)[J] Soil and Environment 2002 11(4) 422-420
[23] QUALLS R G HAINES B L STEIN C et al Fluxes of dissolved organic nutrients and humic substances in a deciduous forest[J] Ecology 1991 72 254-266
[24] 黄泽春 陈斌 雷梅 陆生态系统中水溶性机质环境效应[J] 生态学报 2002 22(2) 259-269
HUANG ZECHUN CHEN TONGBIN LEI MEI Environmental effect of dissolved organic matters in terrestrial ecosystems a review[J] Acta Ecologica Sinica 2002 22(2) 259-266
[25] Guckert A 土根界面中根分泌物微生物活动施钾影响[A] 见 谢建昌 范钦帧 郑文钦编译 土壤植物营养研究新动态[C] 北京 北京农业学出版社 1992 64-72
GUCKERT A Rootsecretion on the interface between the soil and root and microorganism activity under the affection to fertilize Potassium[A] In XIE JIANCHANG FAN QINGZHEN ZHEN WENQING eds New direction on the soil and plant nutrition[C] Beijing Publishing House of Beijing Agricultural University 1992 64-72
[26] GUGGENBERGER G ZECH W SCHULTEN H R Formation and mobilization pathways of dissolved organic matter Evidence from chemical structural studies of organic matter fractions in acid forest floor solutions[J] Organic Geochemistry 1994 21 51-66
[27] YAVITT J B FAHEY T J An experimental analysis of solution chemistry in a lodgpole pine forest floor[J] Oikos 1984 43 222-234
[28] YANO Y MCDOWELL KINNER N Quantification of biodegradable dissolved organic carbon in soil solution with flowthrough bioreactors[J] Soil Science Society of America Journal 1998 62 1556-1564
[29] KEI N KOYO Y Role of dissolved organic matter in translocation of nutrient cations from organic layer materials in coniferous and broad leaf forests[J] Soil Science and Plant Nutrition 1999 45(2) 307-319
[30] ARZHANOVA V S LUTSENKO T N Dissolved organic carbon and metals in soils of SikhoteAline(Russia)[A] In ROSA C ed Proceedings of the tenth international symposium on waterrock interaction[C] 2001 1421-1424
[31] MARTIN H C Dynamics of solubel organic C and C mineralization in cultivated soils with varying N fertilization[J] Soil Biology and Biochemistry 1999 31(6) 543-550
[32] 振立 土壤微生物量养分循环环境质量评价中意义[J] 土壤 1997(2) 61-69
HE ZHENLI Soil microorganism biomass and its implication on nutrition and environmental quality evaluation[J] Soil 1997(2) 61-69
[33] 高云超 朱文珊 陈文新 秸秆覆盖免耕土壤微生物量养分转化研究[J] 中国农业科学 1994 27(6) 41-49
GAO YUNCHAO ZHU WENSHAN CHEN WENXIN The relationship between soil microbial biomass and the transformation of plant nutrients in straw mulched no tillage soil[J] Chinese Agricultural Science 1994 27(6) 41-49
[34] HAYNES R J Labile organic matter as an indicator of organic matter quality in arable and pastoral soils in New Zealand[J] Soil Biology and Biochemistry 32 211-219
[35] SHOPOV Y Y FORD D C SCHWARCZ H Luminescent microbanding in spelethems Highresolution chronology and paleoclimate[J] Geology 1994 22 407-410
[36] BAKER A BARNES W L SMART P L Speleothem luminescene intensity and spectral characteristics signal calbration and a record of paleovegetation change[J] Chemical Geology 1996 130 65-76
Seasonal changes of dissolved organic carbon in soil
its environmental implication in karst area
CAO Jinhua1 2 PAN Genxing2 YUAN Daoxian1 JIANG Guanghui1
1 Institute of Karst Geology Chinese Academy of Geological Science and Key Laboratory
of Karst Dynamics Ministry of Land and Resources Guilin 541004 China
2 Resources and Environmental College Nanjing Agricultural University Nanjing 210095 China
Abstract The role of dissolved organic carbon (DOC) in soil water (or moisture) in karst process is poorly understood In a Guilin karst experimental site the soil DOC was monthly collected and analysed with the TOCV analyzer from SHIMADZU co Japan The results showed the DOC is the active carbon component and plays important role in soil carbon cycle in karst The changes of soil DOC could be expressed 3 stages during the observation (1) From March to July the soil DOC gradually increased with the temperature rainfall the activities of soil organisms and metabolism (2) From August to November the temperature was kept high however the rainwater was substantially reduced The soil became very dry and the soil microorganisms’ activities greatly decreased The concentration of DOC in soil solution was the lowest (3) From December to February both temperature and rainfall were low The fluctuations of soil DOC however were increased which normally related to the carbon of soil microorganism biomass The seasonal erosion rates of limestone tablets beneath the soil were negatively correlated with soil DOC Based on these results a conceptual model of the carbon cycle and DOC role in karst was putted forward
Key words soil dissolved organic carbon karst process carbon cycle Guilin
文档香网(httpswwwxiangdangnet)户传
《香当网》用户分享的内容,不代表《香当网》观点或立场,请自行判断内容的真实性和可靠性!
该内容是文档的文本内容,更好的格式请下载文档