Heavy Metal Fluxes in Tropical Urban Forest Soil in Abidjan District (Côte d’Ivoire)

In Western Africa, the growth of cities has led to natural resource pollution, especially air pollution. Urban forests play a key role in filtering atmospheric particles and pollutants through the canopy before reaching the soil. This study aims to quantify heavy metal fluxes in an urban forest in the district of Abidjan in order to assess its role in the protection of natural resources. A monitoring of wet deposition (throughfall and open field rain) and litterfall was carried out for six months in the urban forest of the National Floristic Center located in Abidjan, C?te d’Ivoire. The results show that the soil of this urban forest is a ferralsol type characterized by a sandy-clay texture and a low load of coarse elements. The annual litterfall is estimated to 12.16 ± 0.71 t·ha-1·yr-1, similar to other tropical forests. Annual quantities of rain and throughfall are in the range of the rainfall recorded in the district of Abidjan (2013 ± 152 and 1773 ± 51 mm). Chemical analyses showed that litter and rainfall contain Mn, Zn, Ni, Cr, Cd and Hg. Manganese and Zn are the most abundant elements and Hg the least abundant in both rainfall and litter. The main source of input of the heavy metals into the urban forest soil is associated with biological recycling through the litter. The litterfall contributes to metal fluxes in soil 109 times greater than metal fluxes carry by wet depositions (open field rain and throughfall). However, a detailed study of rainfall showed that the forest canopy constitutes a barrier for the transfer of heavy metal to urban soil. This is indicated by a decrease in heavy metal content from open field rain to throughfall. Consequently, this study recommends the creation and maintenance of urban forests to increase biomass canopy and improve atmospheric air quality for West African cities undergoing constant change and development.

Soil enzyme activities and their indication for fertility of urban forest soil

To reveal the biological characteristics of urban forest soil and the effects of soil enzyme on soil fertility as well as the correlation between physicochemical properties and enzyme activities,44 urban forest soil profiles in Nanjing were investigated.Basic soil physicochemical properties and enzyme activities were analyzed in the laboratory.Hydrogen peroxidase,dehydrogenase,alkaline phosphatase,and cellulase were determined by potassium permanganate titration,TTC(C_(19)H_(15)N_(4)·Cl)colorimetry,phenyl phosphate dinatrium colorimetry,and anthrone colorimetry,respectively.The result showed that soil pH,organic carbon(C),and total nitrogen(N)had great effects on hydrogen peroxidase,dehydrogenase,and alkaline phosphatase activities in 0–20 cm thick soil.However,pH only had great effect on hydrogen peroxidase,dehydrogenase,and alkaline phosphatase activities in 20–40 cm thick soil.Hydrogen peroxidase,dehydrogenase,and alkaline phosphatase were important biological indicators for the fertility of urban forest soil.Both in 0–20 cmand 20–40 cmsoil,soil enzyme system(hydrogen peroxidase,dehydrogenase,alkaline phosphatase,and cellulase)had a close relationship with a combination of physicochemical indicators pH,organic C,total N,available K,available P,cation exchange capacity(CEC),and microbial biomass carbon(C_(mic)).The more soil enzyme activities there were,the higher the fertility of urban forest soil.

Effects of Urbanization,Soil Property and Vegetation Configuration on Soil Infiltration of Urban Forest in Changchun,Northeast China

Urban forest soil infiltration, affected by various factors, is closely related with surface runoff. This paper studied the effect of urban forest types, vegetation configuration and soil properties on soil infiltration. In our study, 191 typical plots were sampled in Changchun City, China to investigate the soil infiltration characteristics of urban forest and its influencing factors. Our results showed that the steady infiltration rates of urban forest soil were highly variable. High variations in the final infiltration rates were observed for different vegetation patterns and compaction degrees. Trees with shrubs and grasses had the highest infiltration rate and trees with bare land had the lowest infiltration rate. In addition, our results showed that the soil infiltration rate decreased with an increase in the bulk density and with a reduction in the soil organic matter content and non-capillary porosity. The soil infiltration rate also had significantly positive relationships with the total porosity and saturated soil water content. Urban soil compaction contributed to low soil infiltration rates. To increase the infiltration rate and water storage volume of urban forest soil, proper techniques to minimize and mitigate soil compaction should be used. These findings can provide useful information for urban planners about how to maximize the water volume of urban forest soil and decrease urban instantaneous flooding.

Soil nitrogen transformations varied with plant community under Nanchang urban forests in mid-subtropical zone of China

Soil N transformations using the polyvinyl chloride （PVC） closed-top tube in situ incubation method were studied in Nanchang urban forests of the mid-subtropical region of China in different months of 2007. Four plots of 20 m × 20 m were established in four different plant communities that represented typical successional stages of forest development including shrubs, coniferous forest, mixed forest and broad- leaved forest. Average concentrations of soil NH4^＋-N from January to December were not different among the four plant communities. The concentrations of soil NO3^--N and mineral N, and the annual rotes of ammonification, nitrification and net N-mineralization under the early successional shrub community and coniferous forest were generally lower than that of the late successional mixed and broad-leaved forests （p〈0.05）. Similar differences among the plant communities were also shown in the relative nitrification index （NH4^＋-N/NO3^--N） and relative nitrification intensity （nitrification rate/net N-mineralization rate）. The annual net N-mineralization rate was increased from younger to older plant communities, from 15.1 and 41.4 kg.ha^-1.a^-1 under the shrubs and coniferous forest communities to 98.0 and 112.9 kg.ha^-1.a^-1 under the mixed and broad-leaved forests, respectively. Moreover, the high annual nitrification rates （50-70 kg.ha^-1.a^-1） and its end product, NO3-N （2.4-3.8 mg·kg^-1）, under older plant communities could increase the potential risk of N loss. Additionally, the temporal patterns of the different soil N variables mentioned above varied with different plant community due to the combined affects of natural biological processes associated with forest maturation and urbanization. Our results indicated that urban forests are moving towards a state of＂N saturation＂ （extremely niUification rate and NO3^--N content） as they mature.

Woody Vegetation and Soil Characteristics of Residential Forest Patches and Open Spaces along an Urban-to-Rural Gradient

As the process of urbanization advances across the country, so does the importance of urban forests, which include both trees and the soils in which they grow. Soil microbial biomass, which plays a critical role in nutrient transformation in urban ecosystems, is affected by factors such as soil type and the availability of water, carbon, and nitrogen. The aim of this study was to characterize residual forest patches and open fields in residential areas in the City of Knoxville. A field study was conducted to investigate tree species diversity and determine spatial and temporal soil characteristics along an urban-to-rural gradient. Tree diversity did not differ significantly for residential urban and rural plots in Knoxville, Tennessee. Biologically, there was no indication that soils were affected by tree diversity, in terms of soil microbial biomass C/N along an urban-to-rural gradient in Knoxville residential plots. Rural soils did differ physically from urban soils, cation exchange capacity (CEC) and soil moisture content (GSM). Similarly, physical soil properties such as bulk density, both urban and rural sites were negatively correlated with tree diversity. Results indicate that although the urban-rural gradient is subject to urban environmental stressors, the urban ecosystem is resilient in maintaining the ecosystem functions of more natural systems.

北京中心城区城市森林土壤理化性质与植物群落特征的相关性

城市森林是城市生态系统的重要组成部分,而土壤是城市森林可持续发展的基础。在北京中心城区城市森林选取3种典型群落类型样方29个,结合调研植物群落特征,分3层采集0~60cm土壤样品,采用方差分析与多重比较明确北京中心城区城市森林土壤理化性质状况,并对其与植物群落特征的相互作用进行研究。结果表明:1)北京中心城区城市森林土壤容重和电导率处于适宜植物生长范围内,但土壤pH值偏碱性,土壤养分含量相对匮乏;随着土层加深,土壤pH值、有机质、全氮、碱解氮和有效磷含量逐渐降低,差异显著(P<0.05)。除群落郁闭度外,群落特征指标与土壤养分指标多项呈显著正相关。2)植物群落在25~35 a时期到达稳定增长期,土壤养分含量最佳。3)适度提高群落中落叶阔叶型植物的比例、增加植物凋落物和林下植被生物量则对土壤有利。总之,对北京中心城区城市森林应考虑植物群落的差异性,进行针对性的建造管理及制定养护措施,从而长效稳定地促进城市森林健康可持续发展。

北京城市森林林下植物多样性与土壤因子的相关性

以北京平原造林工程营建的城市森林为研究对象,对不同群落类型的林下植物多样性、土壤理化性质、林下植物多样性与土壤因子的相关性进行研究。结果表明:阔叶混交林的Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson优势度指数、Margalef丰富度指数均显著高于其他群落类型(P<0.05)。除土壤pH外,不同群落类型的土壤理化指标均存在显著差异(P<0.05),其中,阔叶混交林的土壤理化指数均优于其他群落类型。所有群落类型的土壤理化性质随土层深度的增加呈规律性变化,即土壤pH、土壤密度、土壤含水量呈上升趋势,土壤总孔隙度、有机碳、有机质、全氮、全磷、有效磷、速效钾则呈下降趋势。相关性研究表明,0<h≤20 cm土层的土壤理化性质对林下植物的多样性影响最高,其中,土壤有机质、有机碳是影响林下植物Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson优势度指数、Margalef丰富度指数的主要因素,土壤全氮、全磷、速效钾也对林下植物的Shannon-Wiener多样性指数、Margalef丰富度有一定影响。城市森林群落应注重营造复合群落类型,适当保留林地内的凋落物,提高土壤有机质质量分数,使其与土壤形成良好的协同效应,进而维持城市森林林下植物多样性的稳定。

典型城乡绿化树种土壤微生物组成和多样性的环境响应差异

城市化带来经济繁荣的同时引起了环境问题。城市树木作为城市生态环境的绿化景观的同时还具有缓解环境问题的功能。土壤环境作为城市树木的生长环境,其健康状况直接影响到城市树木的生长状况,而土壤微生物作为土壤生态系统中重要的生物群落,在土壤环境中充当养分和储存的作用,与城市树木共同维系城市生态功能。在土壤微生物中,土壤表层的土壤细菌与真菌群落能对环境变化迅速反应,因此可作为测定城市化等环境变化对于土壤生态系统的指标。为探究土壤细菌和真菌群落沿城乡环境梯度的响应差异,沿北京市的城区-近郊-远郊梯度上共选取7个公园中的国槐林作为研究样地,挖取其根际土壤用于土壤微生物测定,进而探讨国槐根际土壤细菌与真菌群落在城市化影响下的群落组成与物种多样性的响应差异,并找出影响其分布的环境因子。结果表明:(1)土壤微生物的群落分布与组成会受到城市化的影响,具体表现为土壤细菌与真菌群落在城乡环境梯度上均存在显著差异。其中土壤细菌群落共检测出41大类,其中放线菌、γ变形菌、拟杆菌、粘球菌以及厚壁菌在城乡梯度上存在显著差异。而土壤真菌群落共检测出16大类,其中担子菌与罗泽真菌在城乡梯度上存在显著差异。(2)影响土壤微生物群落分布的环境因子包括土壤理化性质和气候因子两方面,其中土壤细菌群落分布的环境因子包括土壤pH、土壤有机碳、土壤全氮以及年均温,而影响土壤真菌群落分布的环境因子包括土壤有机碳、土壤全氮、土壤全磷以及年降水。(3)在城市化的影响区域中,近郊是受城市化影响程度最大的区域,其中土壤细菌群落在近郊区域的群落组成有一定重合度,而土壤真菌群落在整个城乡梯度上均可完全分开。(4)土壤细菌群落相比土壤真菌群落在城乡梯度上更容易受到环境因子的影响,其环境敏感度较高。

长沙城市森林土壤7种重金属含量特征及其潜在生态风险

采用调查分析方法,研究长沙城市森林土壤Zn、Cu、Ni、Pb、As、Cd、Hg7种重金属含量,并以长沙市土壤背景值和湖南省土壤背景值为参比值,采用Hakanson潜在生态危害指数法评价不同城市化梯度森林土壤重金属潜在生态风险。结果表明:7种重金属的平均含量均随着城市化程度提高而增加,Pb增幅最大,As增幅最小。同一城市化梯度森林土壤均以Zn平均含量最高,Cd最低,但均未超过土壤环境质量标准(GB15618—1995)Ⅱ级标准值。在城市中心区,桂花树林、樟树+桂花树混交林土壤Zn、Cu、Pb、As、Hg平均含量普遍较高,而樟树+马尾松混交林、桂花树+杜英混交林土壤Cu、Ni、As、Cd、Hg平均含量普遍较低,Pb、Zn空间分布差异明显,Cd、Ni、As空间分布比较均匀,Cu、Ni、Pb、As、Cd、Hg之间(除Cd与As、Ni之间外)均存在显著(P<0.05)或极显著(P<0.01)的相关性,与土壤有机质之间也呈显著(P<0.05)或极显著(P<0.01)的相关性,Zn、Cu、Ni、Pb、As、Cd、Hg主要是人为输入;中心区森林土壤重金属的潜在生态危害已达到中等生态危害程度,边缘区接近中等生态危害程度,郊区为轻微生态危害程度,Zn、Cu、Ni、Pb、As均为轻微生态危害程度,Cd、Hg已达到中等生态危害程度以上。

不同功能区城市林业土壤黑碳含量及来源——以南京市为例

由于城市化过程中人为活动的影响,城市林业土壤的性质发生了很大变化。城市林业土壤黑碳由于来源的多样性和受到人为活动的影响,其分布表现出独特的特征。以南京市为对象,调查分析了不同功能区城市林业土壤黑碳的含量及可能来源。结果表明:不同功能区城市林业土壤黑碳含量差异很大,其变幅为0.77—21.27g/kg。道路绿化带土壤黑碳含量显著高于其它功能区,居民区含量最低。黑碳在土壤表层中含量均高于表下层,黑碳富集于土壤表层。道路绿化带表层土壤黑碳含量与有机碳含量的比值(BC/SOC)为0.55,土壤黑碳的碳同位素比值(δ^(13)C_(PDB))为-27.04‰,与其它功能区差异显著,城市交通污染对土壤黑碳积累产生强烈影响。

长沙城市森林土壤理化性质及碳贮量特征

采用现场实测与实验室分析相结合的研究方法,对长沙市城市森林土壤理化性质及碳贮量特征进行了研究,结果表明：（1）土壤pH值为4.69;有机质含量为17.59 g.kg-1;全N、全P含量分别为0.99、0.38 g.kg-1,且有效率低,均为2%;全K含量为6.13 g.kg-1,属适量K型土壤;全Ca、全Mg含量分别为0.79、3.00 g.kg-1。（2）土壤微量元素含量依次排序为Fe〉Mn〉Zn〉Cu〉Pb〉Ni〉Co〉Cd,全Cu、全Zn、全Ni、全Pb均未超过我国土壤环境质量标准（GB15618—1995）中的二级和三级标准,长沙市城市森林土壤可以作为农林地使用。（3）土壤有机碳含量为6.07~19.34 g.kg-1,有机碳贮量为84.78 t.hm-2,均以土壤表层最多,并随土层的增加而减少。研究结果可为长沙城市森林碳汇源功能的估算提供参考数据和理论依据。

南京城市林业土壤的肥力特征分析

采集南京市不同功能区林地0—20cm和20～40cm土壤，分别测定土壤的理化性质和酶活性。研究结果表明，南京城市林业表层土壤（0—20cm）的容重大，孔隙度和渗透性小；土壤质地以粉壤土为主，所占比例为60．42％，土壤中普遍含有砾石，但含量不是很高；土壤以中性土和碱性土为主，非天然林土壤的pH明显高于城郊天然林下土壤；土壤有机质和全氮含量偏低，土壤的阳离子交换量（CEC）偏高，非天然林土壤中有效磷富集，但城郊天然林土壤有效磷缺乏，土壤速效钾富集。0—20cm和20～40cm土壤中，过氧化氢酶活性平均值分别为0．25mL／g和0．31mL／g，脱氢酶活性平均值分别为32．14mg／g和20．91mg／g，碱性磷酸酶活性平均值分别为16．7mg／kg和9．5mg／kg，纤维素酶活性平均值分别为0．0021mg／g和0．001mg／g。过氧化氢酶活性、脱氢酶活性和碱性磷酸酶活性与土壤有机质和全氮含量都有显著相关性，是表征城市林业土壤肥力的重要生物指标。

绿化植物废弃物覆盖对上海城市林地土壤肥力的影响

研究绿化植物废弃物覆盖对上海城市林地土壤肥力的影响。结果表明:绿化植物废弃物覆盖能降低土壤密度,提高土壤保水能力,增加总孔隙度和毛管孔隙度尤其是非毛管孔隙度;在试验设计的6120kg·hm-2覆盖量范围内,覆盖能显著增加土壤有机质、全氮、全磷、水解性氮、有效磷和速效钾含量,且覆盖用量与这些土壤肥力指标成极显著正相关;土壤全钾含量的增加要在覆盖160天后且覆盖量高时才出现;覆盖后土壤微生物生物量碳、氮含量也显著增加,微生物周转速率加快,周期缩短,转移量增加,土壤微生物活性增强,有利于土壤养分的循环和保持;土壤微生物生物量碳、氮含量与土壤主要肥力指标显著正相关,能有效评价绿化植物废弃物覆盖对土地的改良效果。绿化植物废弃物覆盖对提高城市土壤质量、降低绿地养护费用有积极作用,也有利于节约型城市园林绿化的建设。

广州市城市森林土壤重金属污染状况及其评价

城市森林土壤能储淤城市环境中的重金属污染元素,影响土壤环境质量。文章对广州市的城市森林区域中土壤重金属的污染状况进行研究,应用单项污染元素指数和综合污染指数对广州市城市森林土壤进行环境质量评价,结果表明:广州市机场高速林带林区土壤中As、Pb、Cd三重金属污染元素超标,广深铁路林带林区土壤中Cd重金属元素超标,其他各林区严格控制环境重金属污染物未超标;帽峰山森林公园土壤重金属综合污染指数最低,表明森林群落对重金属污染元素的消减作用明显。土壤酶活性可以表征森林土壤中重金属污染状况,森林土壤中As、Cu、Zn含量与过氧化氢酶活性呈显著负相关性;对可能影响城市森林土壤重金属含量因素的10个因子进行主成分分析,建立了城市森林土壤环境质量评价综合模型。

广州长岗山森林凋落物土壤动物群落结构及季节变化

为了解华南地区城市森林凋落物土壤动物群落结构特征及季节变化,对广州市长岗山自然保护区森林凋落物层土壤动物群落进行了为期1年的逐月采样调查,共采获凋落物土壤动物21817头,隶属于3门9纲22类群,其中蜱螨目和弹尾目为优势类群,二者占全年土壤动物个体总数的70.3%;蠕形马陆亚纲、等足目、蜘蛛目、缨翅目、鞘翅目、膜翅目、鳞翅目幼虫和双翅目幼虫为常见类群,它们的个体数占全年土壤动物总个体数的27.0%。这些主要类群的相对多度和密度随采样季节而改变并与凋落物的湿度存在着一定的相关性。蜱螨目的密度高峰期出现在降雨量最多的5—8月;弹尾目的密度高峰出现在2—7月;缨翅目的密度高峰在8—12月,凋落物湿度过高或过低均使缨翅目密度降低;鞘翅目的密度高峰分别出现在5—8月、11月和翌年2月,而蠕形马陆亚纲的密度高峰期集中在5—6月,而其余月份的密度维持在低水平。蜱螨目(A)和弹尾目(C)个体数之比的大小不一定能反映同一气候带土壤动物的分布特征和规律,因为即使在同一地点,不同的采样时间也会造成A/C值差异悬殊。保留城市森林凋落物对提高城市森林土壤动物的多样性具有重要意义。

南京城市林业土壤可蚀性及影响因素

以南京市城市林业土壤为研究对象,研究了土壤的可蚀性特征及影响因素。结果表明:南京市城市林业土壤属于高易蚀土,土壤抗水蚀能力较弱,容易发生水土流失;不同功能区间,土壤的可蚀性K值和水稳性指数没有显著差异,而渗透性由高到低依次为城郊天然林、公园、道路绿化带、裸地、大学校园。回归分析表明,土壤的可蚀性K值与土壤的粉粒含量呈正相关(r=0.499 7),与黏粒含量呈负相关(r=-0.978 3);土壤的渗透性与容重(r=-0.519 6)和粉粒含量(r=-0.306 3)呈负相关,与有机质(r=0.359 6)、总孔隙度(r=0.367 5)和砂粒含量(r=0.380 1)呈正相关;土壤的体积质量和机械组成是反映城市林业土壤可蚀性的重要指标;城市绿地不同的植被配置方式对防治土壤的流失效果不同,表现为乔、灌、草混交林优于草坪,而裸地效果最差;城市客土和原土的抗蚀性差异不明显,但均存在较高的水土流失风险。

上海市3种森林类型土壤微生物生物量碳和氮的时空格局

土壤微生物生物量作为土壤有机质最活跃的部分,可用来表征土壤肥力水平,而且在维持土壤生态系统平衡方面有重要意义。采用氯仿熏蒸浸提法测定上海市3种城市森林土壤微生物生物量碳含量(C_(mic))和氮含量(N_(mic)),并分析了其空间变化和季节动态。结果表明,林型之间C_(mic)和N_(mic)差异显著,香樟(Cinnamomum camphora)林、水杉(Metasequoia glyptostroboides)林、香樟混交林C_(mic)和N_(mic)变化范围分别为46.57~908.77和10.61~103.64、64.58~480.54和20.14~88.39、57.38~853.18和16.67~148.00 mg·kg^(-1),各林型C_(mic)和N_(mic)均随土壤深度的增加而下降。3种林型除>15~20 cm土层微生物生物量季节变化不显著以外,0~5、>5~10和>10~15 cm 3个土层都有明显季节动态,且最高值均出现在秋季。相关分析表明,土壤微生物生物量与土壤有机碳含量、全氮含量呈极显著正相关(P<0.01),与容重呈极显著负相关(P<0.01),同时N_(mic)受水分和温度的影响较大。不同城市森林中植被与环境因子的共同作用导致土壤有机碳含量和全氮含量的不同,造成土壤微生物生物量的时空格局差异。

树种差异对哈尔滨市土壤理化性质影响及造林启示

东北地区的城市造林树种很多，树种差异对土壤理化性质的影响及其在不同土层深度差异对于适宜树种选择意义重大，但是基于野外长期定位研究结果匮乏。本文选择东北林业大学实验林场和哈尔滨市植物园的8个树种（水曲柳、胡桃楸、云杉、松树、杨树、榆树、黄檗、落叶松）进行0—20、20-40和40～60em分层土壤采样，对土壤pH、土壤电导率、有机碳、碱解氮、全N、速效磷、全P、速效钾、全K等9个指标进行研究。多因素方差分析显示，长期定植于类似土壤条件下，树木能够显著影响土壤各理化指标，但不同土壤层间存在明显差异。基于多重比较结果对各指标进行标准化处理、获得综合得分排名发现，榆树具有较好的土壤肥力维持能力（有机碳、碱解氮、全N、全P、速效磷、速效钾、全K），综合得分38，而杨树表现最差；降低土壤盐碱能力（pH和电导率）来看，黄檗、落叶松得分比较高（〉15），胡桃楸表现最差（7．5）。城市立地是典型困难立地，我们研究结果说明绿化树种选择对于改良城市土壤的重要性：对于贫瘠盐碱的核心区域，造林树种可以选择养分消耗少和降盐碱能力强的树种，对于土壤水肥条件优越的地区（如河道、湿地周边）可以考虑一些养分消耗快、生产力高的树种。

城市森林土壤肥力质量综合评价

城市森林土壤肥力质量的综合评价研究,对城市森林的营建、管理以及对城市生态系统的可持续运行都十分重要。选取土壤容重、质地、pH值、有机质、速效钾和纤维素酶活性6个指标,用改进的内梅罗综合指数法对南京城市森林土壤肥力质量进行了综合评价。结果表明,城市森林土壤综合肥力系数(Q)变幅为0.85～1.51,平均为1.19±0.17;其中,肥力属于"中"一级(1.0≤Q<1.5)的土壤样品占样品总数的90.91%;城郊天然林和林、灌、草混交林土壤肥力系数较高,而道路绿化带和草坪覆盖较低。表明南京城市森林土壤肥力总体处于中等偏低水平,需要加强土壤肥力质量改良;草坪对土壤肥力质量的改良能力较弱。

城市森林土壤肥力质量指标筛选——以南京市为例

土壤质量指标的筛选是科学地进行土壤质量评价的前提。本文以城市森林土壤为研究对象,探讨了土壤肥力指标的筛选方法。采集南京市不同功能区森林土壤样品(0～20cm),分析了24个土壤质量指标。根据指标间的相关性和聚类分析结果,筛选出体积质量(容重)、黏粒含量、分散系数、可蚀性因子K值、水稳性指数、pH值、有机质、速效钾和纤维素酶活性,共9个指标作为城市森林土壤肥力质量评价的因子。