六盘山林区几种土地利用方式对土壤中可溶性有机碳浓度影响的初步研究

doi:10.17521/cjpe.2005.0133

摘要/Abstract

摘要：

测定分析了六盘山林区典型天然次生林(杂灌林、山杨(Populus davidiana)和辽东栎(Quercus liaotungiensis)林)、人工林(13、18和25年华北落叶松(Larix principis-rupprechti))、农田和草地中穿透雨、凋落物淋溶液、土壤溶液和渗漏水溶液及地下水和降雨中可溶性有机碳 (DOC)的浓度。结果显示:5~10月,雨水中DOC浓度为0.80~1.60 mg·L^-1,地下水中在2.43~7.66 mg·L^-1。9~10月,穿透雨中DOC浓度为1.78~15.20 mg·L^-1,其中天然次生林和人工林比农田和草地中高,这些DOC与地表凋落物碳年形成量正相关显著。凋落物浸泡24 h后淋溶产生的DOC浓度为12.30~64.79 mg·L^-1,占凋落物碳贮量比例不足1%;浓度方面,天然次生林比农田和草地分别高400%和153%,人工林比农田和草地分别高194%和50%;比例方面,农田和草地比天然次生林分别高79%和98%、比人工林分别高180%和210%,这些DOC浓度与落叶、小枝、碎小物和腐解物碳贮量的正相关显著。9~10月,0~20 cm土层溶液中DOC浓度为7.88~88.44 mg·L^-1,占土壤有机碳密度的比例不足0.1%,它们随土层加深而下降,其中天然次生林和人工林中下降幅度比农田和草地中大;浓度方面,天然次生林、人工林比农田和草地中高,差异主要在0~10 cm土层;比例方面,天然次生林DOC比例比农田和草地中低,人工林比它们高,差异主要在0~10 cm土层;这些DOC浓度与土壤湿度及凋落物层碳贮量正相关显著。5~10月,0~40 cm土层渗漏水中DOC浓度为5.76~58.84 mg·L^-1,天然次生林、人工林比农田和草地高,差异主要在0~10 cm土层;它们随土层加深而下降,其中天然次生林和人工林下降幅度比农田和草地中大。这些差异可能由土地利用引起的植被和土壤性质改变及其对水文过程的影响所致,说明陆地生态系统中DOC浓度受土地利用变化的影响较大。

关键词: 土地利用变化, 可溶性有机碳, 碳循环

Abstract:

Dissolved organic carbon is an important component of the carbon balance of terrestrial ecosystems and source of energy, carbon, and nutrient transfer from terrestrial to aquatic ecosystems. Land use changes caused by human activities have had major impacts on terrestrial ecosystem carbon cycles, including impacts of soil DOC dynamics. Hence, it is important to understand the impacts of land use changes on DOC for assessing the impacts of land use change on the carbon cycle. Over the last several centuries, extensive areas of native vegetation in the Liupan Mountain Forest Zone have been replaced by croplands or rangelands, whereas in recent decades former arable lands and rangelands have been afforested. However, the impacts of these land-use changes on the terrestrial ecosystem carbon cycle are unclear, especially on the soil DOC dynamics. In order to assess the impacts of land-use changes on soil DOC dynamics, we measured the concentrations of DOC in precipitation, subsurface water, soil leachate, detrital leachate solutions, throughfall, and water percolating through the soil in plots with the same elevation, exposure, and soil types but with different vegetation types. A natural secondary forest dominated by Querces liaotungensis, Populus davidiana, or brushwood, a cropland and rangeland derived from destruction of the natural secondary forests, and a 13, 18 and 25 year old larch plantation, Larix principis-rupprechtii, afforested on former croplands or rangelands were studied.
Our results showed that concentrations of DOC in precipitation and subsurface water from May to October was 0.80 -1.60 mg·L^-1 and 2.43-7.66 mg·L^-1, respectively. From September to October, the concentration of DOC in throughfall was 1.78-15.20 mg·L^-1 which was higher under natural forests or plantations than in croplands or rangelands and positively correlated with annual production of aboveground detritus (p=0.05). The concentration of DOC in detrital leachate solutions, derived from detritus submerged in water for 24 h, was 12.30-64.79 mg·L^-1 and its fraction was not more than 1%. The concentration of detrital DOC was 400% and 153% higher under natural forests than cropland and rangeland, respectively, and 194% and 50% higher under plantation than cropland and rangeland, respectively. Its fraction was 79% and 98% higher in the cropland and rangeland than the natural forest, respectively, and 180% and 210% higher in the cropland and rangeland than the plantation, respectively. The concentration of DOC in detrital leachate was positively correlated with aboveground detrital carbon storage of leaf, branch, humus and litter (p=0.05, n=184). The concentration of DOC in soil solutions in the 0-20 cm deep soil layer was 7.88-88.44 mg·L^-1 and its fraction was not more than 1%. The concentration of soil solution DOC was higher under the natural secondary forest or the plantation than cropland or rangeland, and its fraction was lower under natural forest than cropland or rangeland but higher under the plantation than natural secondary forests. The difference of the soil solution DOC concentration or fraction between the natural secondary forest or plantation and rangeland or cropland was greater at 0-10 cm soil depth than 10-20 cm soil layer. The change of this DOC concentration with soil depth was greater under the natural secondary forest or plantation than cropland or rangeland. The concentration of this DOC was positively correlated with detrital carbon storage and soil water content (p=0.05), and soil water content was the main factor that influenced the concentration of DOC in soil solutions. The concentration of DOC in soil percolation water was 5.76-58.84 mg·L^-1 which was higher under the natural forest or plantation than cropland or rangeland. The difference in this DOC concentration between the natural secondary forest or plantation and rangeland or cropland was greater in the 0-10 cm than 10-40 cm soil layer. The change of this DOC concentration with soil depth was greater under the natural secondary forest or plantation than cropland or rangeland. These differences were ascribed to the differences in vegetation and soil properties that resulted from changes in land use and their consequent impacts on hydrological processes. The results of this study indicate that changes in land use have large impacts on terrestrial DOC concentrations.

Key words: Land use change, DOC, Carbon cycle

吴建国, 徐德应. 六盘山林区几种土地利用方式对土壤中可溶性有机碳浓度影响的初步研究. 植物生态学报, 2005, 29(6): 945-953. DOI: 10.17521/cjpe.2005.0133

WU Jian-Guo, XU De-Ying. DISSOLVED ORGANIC CARBON CONCENTRATIONS IN SOIL UNDER DIFFERENT LAND USES IN THE LIUPAN MOUNTAIN FOREST ZONE. Chinese Journal of Plant Ecology, 2005, 29(6): 945-953. DOI: 10.17521/cjpe.2005.0133

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.plant-ecology.com/CN/10.17521/cjpe.2005.0133

https://www.plant-ecology.com/CN/Y2005/V29/I6/945

图/表 5

图1 不同月份地下水和雨水中DOC浓度图中相同小写和大写字母分别表示不同月份雨水和地下中DOC浓度差异不显著(p=0.05,n=6)

Fig.1 The concentration of DOC in rainwater and underground water from May to October The same small and capital letter within each row indicate no significant difference at 5% level for concentration of DOC in rain and underground water respectively in different month (n=6)

图2 不同土地利用方式下9和10月穿透雨中DOC平均浓度 AA:灌木林 Brushwood BB:山杨林Natural secondary forest dominated by Populus davidiana CC:辽东栎林Natural secondary forest dominated by Quercus liaotungensis DD:农田Cropland EE:草地Rangeland FF:13年落叶松The plantation of Larix principis-rupprechtii with age 13-year-old GG:18年落叶松The plantation of Larix principis-rupprechtii with age 18-year-old HH: 25年落叶松The plantation of Larix principis-rupprechtii with age 25-year-old 图柱中相同大写和小写字母分别表示不同土地利用方式间9和10月冠层穿透雨中DOC浓度差异不显著(p=0.05,n=8) The same small and capital letter within each row indicate no significant difference at 5% level for concentration of DOC in throughfall in September and October respectively under different land use (n=8)

Fig.2 The concentration of DOC in throughfall under different land use in September and October

图3 地上凋落物淋溶液中DOC浓度(左)和比例(右) 土柱中相同小写字母表示不同土地利用方式间地上凋落物淋溶液DOC浓度(左)和比例(右)差异不显著(p=0.05,n=20)同图2

Fig.3 The concentration (left)and fraction (right) of DOC in leaching solution from aboveground detritus The same small letter within each column indicate no significant difference at 5% level for concentration (left)and fraction(right) of DOC in leaching solution from aboveground detritus respectively under different land use (n=20) AA,BB,CC,DD,EE,FF,GG,HH:See Fig. 2

图4 9和10月土壤溶液中DOC浓度和占土壤有机碳的比例图柱中相同字母表示不同土地利用方式间土壤溶液DOC浓度没有显著差异(p=0.05,n=32) AA,BB,CC,DD,EE,FF,GG,HH:同图2

Fig.4 The concentration and fraction of DOC in soil solution in September and October The same alphabetic within each column indicate no significant difference at 5% level for concentration and fraction of DOC in soil solution in September and October under different land use (n=32) AA,BB,CC,DD,EE,FF,GG,HH:See Fig 2

图5 土壤渗漏水溶液中DOC浓度图列中相同字母表示不同土地利用方式间土壤DOC浓度没有显著差异(p=0.05,n=32) AA,BB,CC,DD,EE,FF,GG,HH: 同图2

Fig.5 The mean concentration of DOC in percolation water in different soil depth The same capital letter within each column indicate no significant difference at 5% level for mean concentration of DOC in percolation water under different land use(n=32) AA,BB,CC,DD,EE,FF,GG,HH: See Fig. 2

参考文献 41

[1]	Cancès B, Ponthieu M, Castrec-Rouelle M, Aubry E, Benedetti MF (2003). Metal ions speciation in a soil and its solution:experimental data and model results. Geoderma, 113,341-355. DOI URL
[2]	Cao J (曹军), Tao S (陶澍) (1999). The dynamic of organic matter emission from soil and sediment. Acta Scientiae Circumstantiate (环境科学学报), 19,297-302. (in Chinese with English abstract)
[3]	Cao JH (曹建华), Pang GX (潘根兴), Yuang DX (袁道先) (2000). The impacts of different plant litter on leaching of soil organic carbon and its effects of rock leaching. The Study of Quaternary (第四季研究), 20,359-366. (in Chinese with English abstract)
[4]	Ciglasch HJ, Lilienfein K, Kaiser W (2004). Dissolved organic matter under native Cerrado and Pinus caribaea plantations in the Brazilian savanna. Biogeochemistry, 67 (2),157-182. DOI URL
[5]	Chantigny MH (2003). Dissolved and water-extractable organic matter in soils: a review on the influence of land use and management practices. Geoderma, 113,357-380. DOI URL
[6]	Editorial Board of the Forest in Ningxia HuiZu Autonomy Region(宁夏森林编辑委员会) (1990). The Forest in Ningxia HuiZu Autonomy Region (宁夏森林). China Forestry Publishing House, Beijing,30-69. (in Chinese)
[7]	Frøberg M, Berggren D, Bergkvist B, Bryant C, Knicker H (2003). Contributions of Oi,Oe and Oa horizons to dissolved organic matter in forest floor leachates. Geoderma, 113,311-322. DOI URL
[8]	Glatzel S, Kalbitz K, Dalva M, Moore T (2003). Dissolved organic matter properties and their relationship to carbon dioxide efflux from restored peat bogs. Geoderma, 113,397-411. DOI URL
[9]	Guggenberger G, Kaiser K (2003). Dissolved organic matter in soil:challenging the paradigm of sorptive preservation. Geoderma, 113,293-310. DOI URL
[10]	Guggenberger G, Zech W (1993). Dissolved organic carbon control in acid forest soils of the fichtelgebirge (Germany) as revealed by distribution patterns and structural composition analyses. Geoderma, 59,109-129. DOI URL
[11]	Hope D, Billet MF, Cresser MS (1994). A review of the export of carbon in river water: fluxes and processes. Environmental Pollution, 84,301-324. DOI URL PMID
[12]	Jansen B, Nierop KGJ, Verstraten JM (2003). Mobility of Fe(Ⅱ),Fe(Ⅲ) and Al in acidic forest soils mediated by dissolved organic matter:influence of solution pH and metal/organic carbon ratios. Geoderma, 113,323-340. DOI URL
[13]	Johnson KDC, Driscoll CT (2001). Organic matter chemistry and dynamics in clear-cut and unmanaged hardwood forest ecosystems. Biogeochemistry, 54,51-83. DOI URL
[14]	Kalbitz K (2001). Properties of organic matter in soil solution in a germane fen area as dependent on land use and depth. Geoderma, 104,203-214. DOI URL
[15]	Kaiser K, Zech W (1998). Soil dissolved organic matter sorption as influenced by organic and sesquioxide coating and sorbed sulfate. Soil Science Society American Journal, 62,129-136. DOI URL
[16]	Kaiser K, Guggenberger G, Haumaier L, Zech W (2001). Seasonal variations in the chemical composition of dissolved organic matter in organic forest floor layer leachates of old-growth scots pine ( Pinus sylvestris L) and European beech ( Fagus sylvatica L) stands in northeastern Bavaria, Germany. Biogeochemistry, 55,103-143. DOI URL
[17]	Kalbitz K, Solinger S, Park JH, Michalzik B, Matzner E (2000). Controls on the dynamics of dissolved organic matter in soils: a review. Soil Science, 165,277-304. DOI URL
[18]	Kalbitz K, Geyer S (2002). Different effects of peat degradation on dissolved organic carbon and nitrogen. Organic Geochemistry, 33,319-326. DOI URL
[19]	Kalbitz K, Schmerwitz J, Schwesig D, Matzner E (2003). Biodegradation of soil-derived dissolved organic matter as related to its properties. Geoderma, 113,273-291. DOI URL
[20]	Kawahigashi M, Sumida H, Yamamoto K (2003). Seasonal changes in organic compounds in soil solutions obtained from volcanic ash soils under different land uses. Geoderma, 113,381-396. DOI URL
[21]	Li YZ (李韵珠), Li BG (李保国) (1998). The Transform of Soil Solution (土壤溶质运移). Science Press, Beijing. (in Chinese)
[22]	Ma XH (马雪华) (1994). The Methods of Study in Situ Forest Ecosystem (森林生态系统定位研究方法). Chinese Science and Technology Press, Beijing. (in Chinese)
[23]	Marschner B, Kalbitz K (2003). Controls of bioavailability and biodegradability of dissolved organic matter in soils. Geoderma, 113,211-235. DOI URL
[24]	Mcdowell WH, Likens G (1988). Origin, composition, and flux of dissolved organic carbon in the Hubbard brook valley. Ecological Monographs, 58,177-195. DOI URL
[25]	Mcdowell WH (2003). Dissolved organic matter in soils-future directions and unanswered questions. Geoderma, 113,179-186. DOI URL
[26]	Michalzik B, Kalbitz K, Park J-P, Solinger S, Matzner E (2001). Fluxes and concentrations of dissolved organic carbon and nitrogen-a synthesis for temperate forests. Biogeochemistry, 52,173-205. DOI URL
[27]	Michalzik B, Matzner E (1999). Fluxes and dynamics of dissolved organic nitrogen and carbon in a spruce(Picea abies Karst)forest ecosystem. Europen Journal Soil Science, 50,579-590.
[28]	Michalzik B, Tipping E, Mulder J, Gallardo LJF, Matzner E, Bryant CL, Clarke N, Lofts S, Vicente EMA (2003). Modelling the production and transport of dissolved organic carbon in forest soils. Biogeochemistry, 66 (3),241-264.
[29]	Moore TR (1998). Dissolved organic carbon: sources, sinks, and fluxes and role in the soil carbon cycle. In: Lal R, Kimble JM, Follett RF, Stewart BA eds. Soil Processes and the Carbon Cycle. CRC Press, Boca Raton, Florida, 281-292.
[30]	Neff JC, Asner GP (2001). Dissolved organic carbon in terrestrial ecosystems: synthesis and a model. Ecosystems, 4,29-48.
[31]	Nelson PN, Baldock JA, Oades JM (1993). Concentration and composition of dissolved organic carbon in streams in relation to catchments soil properties. Biogeochemistry, 19,27-50.
[32]	Piirainen S, Finer L, Mannerkoski H, Starr M (2002). Effects of forest clear-cutting on the carbon and nitrogen fluxes through podzolic soil horizons. Plant and Soil, 293,301-311.
[33]	Qualls RG, Haines BL (1992). Biodegradability of dissolved organic matter in forest throughfall,soil solution and stream water. Soil Science Society of American Journal, 56,578-586.
[34]	Robertson SMC, Horning M, Kennedy VH (2000). Water chemistry of throughfall and soil water under four tree species at gisburn,northwest England,before and after felling. Forest Ecology and Management, 129,101-117.
[35]	Schimel DS (1995). Terrestrial ecosystems and the carbon cycle. Global Change Biology, 1,77-91.
[36]	Solinger S, Kalbitz K, Matzner E (2001). Controls on the dynamics of dissolved organic carbon and nitrogen in a central European deciduous forest. Biogeochemistry, 55,327-349.
[37]	Watson RT, Noble IR, Bolin B, Ravindranath NH, Verardo DJ, Dokken DJ (2000). Land Use, Land Use Change,and Forestry: a Special Report of the IPCC. Cambridge University Press, Cambridge,189-217.
[38]	Willey JD, Kieber RJ, Eyman M S, Ayery Jr GBA (2000). Rainwater dissolved organic carbon: concentrations and global flux. Global Biogeochemical Cycles, 14,139-148.
[39]	Wu JG (吴建国), Zhang XQ (张小全), Xu DY (徐德应) (2004). Impact of land-use change on soil carbon storage. Chinese Journal of Applied Ecology (应用生态学报), 15,593-599. (in Chinese with English abstract)
[40]	Zhang WR (张万儒), Xu BT (许本彤) (1986). The Methods of Study in Situ Forest Soil (森林土壤定位研究方法). China Forestry Publishing House, Beijing. (in Chinese)
[41]	Zsolnay A (2003). Dissolved organic matter:artifacts,definitions,and functions. Geoderma, 113,187-209.