徐州市城市绿地土壤碳储量及质量评价

【作者】 司志国；

【导师】 俞元春；

【作者基本信息】 南京林业大学 ， 水土保持与荒漠化防治， 2013， 博士

【摘要】 城市绿地土壤是城市生态系统的重要组成部分，是绿色植物生长的介质和营养供给者，同时对有害物质有过滤、氧化、吸附、固定及净化城市环境的作用，它关系到城市园林植物的生长、人居环境质量与人类健康。因此，开展城市绿地土壤研究对促进生态化城市建设和保证城市生态环境可持续发展具有重要意义。通过野外调查和室内分析相结合的方法，测定了徐州市城市绿地土壤碳储量、理化性质及酶活性，采用主成分分析的方法建立了土壤质量评价最小数据集，并对徐州市城市绿地土壤质量进行了综合评价，研究结果表明：（1）徐州城市绿地土壤碳储量：徐州市城市绿地土壤0～100cm土层有机碳总储量为5.63×10⁸kg，无机碳总储量为1.51×10⁸kg，总碳储量为7.14×10⁸kg。徐州市城市绿地土壤碳主要储存在附属绿地、公园绿地及防护绿地，占总碳储量的89.09%。影响有机碳库的因素包括pH值、土壤密度、非毛管孔隙度、总孔隙度、田间持水量、速效钾、全氮、水解性氮、阳离子交换量，影响无机碳库的因素包括pH值、土壤密度、非毛管孔隙度、总孔隙度、全氮、水解性氮、电导率。（2）徐州城市绿地土壤物理性质：徐州市城市绿地土壤以粉（砂）质粘壤土、壤土、粉（砂）质粘土和粉（砂）壤土为主；0～20cm层土壤密度平均值为1.25g.cm-3，除了防护绿地土壤密度较小外，其他绿地土壤密度差异不显著，20～40cm层土壤密度平均值为1.33g.cm3，不同绿地类型土壤密度差异不显著。徐州市城市绿地土壤60%以上的土壤密度偏大，对城市园林植物的生长有一定影响。0～20cm层粘粒含量平均值为30.92%，防护绿地粘粒含量最高，公园绿地粘粒含量最低，20～40cm层粘粒含量平均值为33.12%，不同绿地土壤类型之间没有显著差异。徐州市城市绿地土壤75%粘粒含量过高或过低，不利于土壤肥力功能的发挥。0～20cm层和20～40cm层田间持水量平均值分别为30.17%和26.35%，不同绿地类型差异不显著。0～20cm土层毛管孔隙度和总孔隙度平均值分别为43.33%和54.46%，不同类型土地土壤差异不显著，非毛管孔隙度平均值为11.21%，防护绿地最高，道路绿地最低。20～40cm层毛管孔隙度和总孔隙度平均值分别为40.43%和48.78%，不同绿地类型之间差异不显著，非毛管孔隙度平均值为9%，附属绿地最高，道路绿地最低。从总体上看，50%绿地土壤的通气透水能力较差，不利于植物的生长发育。（3）徐州城市绿地土壤化学性质：在0～20cm土层中，土壤速效磷含量和速效钾含量平均值分别为2.22mg.Kg^-1和200.19mg.Kg^-1，不同类型绿地土壤没有显著差异，水解性氮含量平均值为85.50mg.Kg^-1，防护绿地含量最高，附属绿地含量最低。在20～40cm土层中，速效磷含量平均值为1.87mg.Kg^-1，不同类型绿地土壤没有显著差异，速效钾含量平均值为167.54mg.Kg^-1，水解性氮含量平均值为59.51mg.Kg^-1，公园绿地速效钾含量最高，防护绿地水解性氮含量最高，道路绿地速效钾含量和水解性氮含量最低。在0～20cm土层中，全磷含量平均值为0.94g.Kg^-1，街头绿地含量最高，附属绿地含量最低，全氮含量平均值为0.96g.Kg^-1，防护绿地含量最高，街头绿地含量最低，全钾含量平均值为23.91g.Kg^-1，街头绿地最高，生产绿地最低。在20～40cm土层中，全磷和全钾含量平均值分别为0.88g.Kg^-1和24.09g.Kg^-1，全钾含量平均值为24.09g.Kg^-1，公园绿地全磷含量最高，街头绿地全钾含量最高，全钾和全磷在生产绿地含量最低，全氮含量平均值为0.73g.Kg^-1，防护绿地含量最高，附属绿地含量最低。在0～20cm土层中，有机质平均含量为22.37g.Kg^-1，阳离子交换量平均值为15.5cmol（＋）．Kg^-1，在20～40cm土层中，有机质含量平均值为17.84g.Kg^-1，阳离子交换量平均值为14.54cmol（＋）.Kg^-1，在上层（0～20cm）和下层（20～40cm）中，防护绿地土壤有机质含量和阳离子交换量均达到了最大值。电导率在0～20cm土层平均值为0.15mS.cm-1，防护绿地最高，生产绿地最低，20～40cm土层平均值为0.15mS.cm-1，不同绿地类型土壤没有显著差异，pH在7.5～8.5的约占93%，徐州城市绿地土壤总体呈碱性。从研究数据可以得出结论，土壤有机质、全氮、速效磷含量普遍偏低，可能会限制园林植物的生长；土壤速效钾富集，能满足植物对钾的需求，土壤保肥能力处于中等及中等靠上水平，盐分含量不会影响园林植物的生长。（4）徐州城市绿地土壤酶活性：在0～20cm土层中，不同绿地类型土壤脲酶之间没有显著差异；道路绿地过氧化氢酶活性最强，防护绿地活性最低；防护绿地磷酸酶活性和蔗糖酶活性最高；街头绿地多酚氧化酶活性最强；在20～40cm土层中，脲酶除了公园绿地显著较高外，其他几种绿地类型没有显著差异；附属绿地过氧化氢酶活性最强，道路绿地活性最低；不同绿地类型磷酸酶之间没有显著差异；防护绿地蔗糖酶活性最高，其他几种绿地类型没有显著差异；街头绿地多酚氧化酶活性较强。对于不同植被类型下土壤来说，林地土壤脲酶和磷酸酶、蔗糖酶活性最高，草灌木磷酸酶和蔗糖酶在草灌木地活性最低，过氧化物酶和过氧化氢酶活性没有显著差异。相关分析表明，总孔隙度、毛管空隙度、田间持水量及pH值对城市绿地土壤酶活性没有影响，土壤密度能显著抑制磷酸酶及蔗糖酶的活性，非毛管空隙度能显著提高磷酸酶、过氧化氢酶及蔗糖酶的活性，自然含水量影响过氧化氢酶活性；速效磷能显著抑制过氧化氢酶和过氧化物酶的活性，速效钾能显著提高脲酶和过氧化物酶的活性，水解性氮和有机质对脲酶、磷酸酶及蔗糖酶有显著影响，阳离子交换量对磷酸酶和蔗糖酶有显著影响；脲酶和过氧化物酶显著负相关，与蔗糖酶、磷酸酶呈极显著正相关，过氧化氢酶和磷酸酶呈显著正相关，与多酚氧化酶呈极显著负相关；磷酸酶与蔗糖酶之间呈极显著相关关系。本研究结果表明，土壤理化性质对土壤酶活性及土壤酶活性之间均有不同程度的相关性，说明土壤理化性质对土壤酶有一定的影响，土壤酶作为评价土壤质量指标是可行的。（5）徐州城市绿地土壤综合评价：通过主成分分析法选取土壤密度、pH值、速效磷、速效钾、水解性氮、阳离子交换量、有机质、粘粒含量等8项指标组成评价徐州市城市绿地土壤质量的最小数据集；并采用内梅罗公式对土壤质量进行了综合评价，0～20cm土壤综合肥力指数（P）大小依次为公园绿地（1.469）、防护绿地（1.326）、道路绿地（1.304）、生产绿地（1.253）、街头绿地（1.300）、附属绿地（1.112）。各个绿地类型0～20cm土壤的肥沃程度均处于中等水平（1.0<P<1.5），对于20～40cm，防护绿地、公园绿地和街头绿地处于中等水平，其他三种绿地处于较差水平（P<1.0）；更多还原

【Abstract】 Urban green space is an important part of city forest ecosystem,is medium and nutrientsupply of green plants,at the same time it can filter,oxidize,adsorb,fix and purify city environment,it influences the growth of city garden plant,the quality of living environment and health ofhuman being. Thus,to develop urban green space is meaningful to promote ecological cityconstruction and ensure city ecological environment to develop sustainably. Through fieldinvestigation and laboratory analysis, we determined carbon storage of land of Xuzhou urbangreen space, and its physical and chemical properties and enzymatic activity, through principalcomponent analysis we established soil quality evaluation of the minimum data set, andcomprehensively evaluate Xuzhou urban green space, what the results show are as the following:（1） In Xuzhou,organic carbon and total reserves of the urban green space land from0to100cm is5.63×10⁸kg,inorganic carbon reserves is1.51×10⁸kg, carbon reserves is7.14×10⁸kg. InXuzhou,carbon reserves of urban green space are mainly in attached green space, public park,andgreen buffer,it occupies89.09%of carbon reserves.（2） In Xuzhou, the urban green space mainly is powder （sand） quality clay loam, loam,powder （sand） clay and powder （sandy） loam, which are good for fertilizer retention ventilatedpermeability and water retention;the average value of density of loam from0to20cm is1.25g.cm-3, only the density of green buffer is small, the differences of the density of other loamare not obvious, the average value of the density of loam from20to40cm is1.33g·cm3,thedifferences between different green space are not obvious. The density of more than60%ofurban green space is a little big in Xuzhou, which has a certain influence on the growth of urbangreen plants. The average value of cosmid content from0to20cm is30.92%, the cosmid contentof green buffer is the highest, and the cosmid content of park is the lowest, the average value ofcosmid content from20to40cm is33.12%, the difference between different green space is notobvious. The cosmid content of75%of urban green space in Xuzhou is too high or too low,which is not good for loam to exert its function. The average value field capacity from0to20cmand from20to40cm are separately20.17%and23.35%, there is no obvious difference betweendifferent green space. Loam capillary porosity and total porosity from0to20cm are separately43.33%and54.46%, there is no obvious difference between different green space, the averagevalue of noncapillary poropsity is11.21%, which of green buffer is the highest, and which ofroad green space is the lowest. The average value of capillary porosity and total porosity from20to40cm are separately40.43%and48.78%,there is no obvious difference between differentgreen space, the average value of noncapillary porosity is9%, which of the attached greenspace is the highest, and which of the road green space is the lowest. Generally, air permeabilityof50%of green space is not good, which is not good for growth of plants.（3） The content of soil available phosphorus and available potassium from0to20cm are respectively2.22mg.Kg^-1 and200.19mg.Kg^-1, there is no significant difference in differentgreen land types, the average value of hydrolyze nitrogen content is85.50mg.Kg^-1, green bufferis the highest, and which of attached green space is the lowest.In20⁴0cm soil layer, the averagevalue of available phosphorus content is1.87mg.Kg^-1, there was no significant differencebetween the different green land types, the average value of available potassium content is167.54mg.Kg^-1, the average value of hydrolyze nitrogen content is59.51mg.Kg^-1, content ofavailable potassium is highest in public park, the hydrolyzable nitrogen content is the highest ingreen buffer, the content of vailable potassium content and hydrolytic nitrogen is the lowest theroad green space. In0²0cm soil layer, the average value of total phosphorus content from0to20cm is0.94g.Kg^-1, street green belt was the highest,the attached green space is the lowest,theaverage value total nitrogen is0.96g.Kg^-1, total nitrogen content of green buffer is the highest,street green belt was the lowest, the average value of total potassium content is23.91g.Kg^-1,street green belt is the highest, nursery the is the lowest. In20⁴0cm soil layer, average contentof total phosphorus and total potassium were respectively0.88g.Kg^-1 and24.09g.Kg^-1, theaverage content of total potassium is24.09g.Kg^-1, content of the total phosphorus is highest inpublic park, street green belt is highest for the total potassium content, thecontent of the totalpotassium and total phosphorus was the lowest in the nursery, average content of total nitrogenis0.73g.Kg^-1, content of green buffer is the highest, attached green space was the lowest. Theaverage content of organic matter and cation exchange capacity from0to20cm are separately22.37g.Kg^-1 and15.5cmol （+）.Kg^-1, The average content of organic matter and cation exchangecapacity from20to40cm are separately17.84g.Kg^-1 and14.54cmol （+）.Kg^-1, the organicmatter and cation exchange capacity is the highest in the green buffer. The conclusion can beconcluded from the research data, soil organic matter, total nitrogen, available phosphorus isgenerally low and limit the garden plant growth;soil available potassium is enrichment and canmeet the demand of plant;fertilizer ability is middle;salt content does not affect to the growth ofgarden plants.（4）There is no significant differences for urease in different greenland types. The activity of peroxidase in street greenland is the highest, whereas the lowest in protection greenland. In theother sides, the phosphatase and saccharase are most activity in protection greenland, and the polyphenoloxidase is most activity in street greenland. In20-40cm soil layers, the urease has no significant differences among the greenland types except the garden greenland. For catalase, the activity is highest in affiliated greenland, while lowest in street greenland. There is no significant differences for phosphatase in different greenland types. the saccharase has no significant differencesamong the greenland types except the protection greenland. The activty of polyphenoloxidase instreet greenland is higher than other greenland types. For soil and different landcover types, the acitivity of urease, phosphatase and saccharase are highest in forest land, and the acitivity of phosphatase and saccharase are lowest in grass land. In addition, the acitivity of peroxidase and catalas e has no significant differences.The total porosity,capillary porosity, Field moisture capacity, fieldmoisture capacity and PH value has nothing effect on oil enzyme activity of urban green space,soil density obviously can block the activity of phosphatase and sucrose enzyme, non-capillaryporosity obviously can promote activity of phosphatase,catalase and sucrose enzyme,naturalwater content has an effect on the activity of peroxidase;available phosphorus obviously canblock the activity of catalase and peroxidase,available phosphorus obviously can promote theactivity of urease and peroxidase, available nitrogen and organic matter has obvious effect onUrease,phosphatase and sucrose enzyme,cation exchange capacity has obvious effect onphosphatase and sucrose enzyme;urease and peroxidase are obviously negative correlated, andare obviously positive correlated with sucrose enzyme and phosphatase, catalase is obviouslypositive correlated with phosphatase, and is obviously negative correlated with polyphenoloxidase;phosphatase is obviously correlated with sucrose enzyme. The researches show that soilphysical and chemical properties and soil enzyme activity and soil enzyme activity itself arecorrelated from different stages, and it means that soil physical and chemical properties has acertain effect on soil enzyme, thus, soil enzyme as soil quality index is feasible.（5） The eight indicators is selected as minimum data of soil quality assessment, includingsoil density,pH,available phosphorus,available potassium,hydrolytic nitrogen,cation exchangecapacity,organic matter,clay content. Soil integrated fertility index（P） from0to20cm varied inthe order of park green space （1.45）,protective green space soil （1.42）,road green space soil（1.37）,production green space soil（1.18）,roadside green space soil （1.17） and attached greenspace soil （1.07）. Soil integrated fertility from0to20cm of all the functional areas was medium（1.0<P<1.5）. Soil integrated fertility from20to40cm of protective green space, park greenspace and roadside green space were medium, other three green space soil were lower（P<1.0）.更多还原