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.     

黑龙江省松嫩平原南部表层土壤肥力质量评价研究

对土壤肥力质量进行定量化评价是为了准确了解土壤肥力状况,进而通过合理施肥,保障土壤养分均衡,实现粮食高产稳产.以黑龙江省松嫩平原南部8.15万k㎡范围表层土壤为研究对象,按照1个点/k㎡的密度采集表层土壤样品20929件,应用地理信息系统(GIS)的Kriging插值方法.对研究区内土壤元素全量进行空间变异特征分析,并在考虑pH值对各元素有效性的影响后,选取评价指标,利用层次分析法确定指标权重,选取隶属度函数模型,采用加法模型得到表层土壤肥力质量综合指数,制作1:200万表层土壤肥力分等图.结果表明,研究区表层土壤元素空间变异性主要受自然因素影响,土壤肥力质量划分为丰富、适量和缺乏三个等别,分别集中分布于研究区中部、东部和西部.     

江苏下蜀林区土壤溶解有机碳与土壤因子的关系

采用TOC-5000A总有机碳仪测定了江苏下蜀森林土壤溶解有机碳(DOC)的含量,分析了土壤DOC与土壤因子的关系。结果表明:酸性森林土壤中,DOC与有机C、全N、碱解N、有效P等养分因子之间呈极显著或显著的正相关关系,土壤DOC与土壤肥力状况关系密切,因而可以作为评价土壤肥力性状的生物学指标。土壤DOC与土壤中有机络合态Fe、有机络合态Al和活性羟基Al之间呈极显著或显著的正相关。土壤中有机C的运输是调整土壤中Al和Fe的溶出及迁移的一个重要因子。土壤DOC与交换性Al、pH值、全P、速效K之间无相关关系。     

杉木林改造前后的土壤肥力对比分析及综合评价

基于福寿林场3个龄组杉木(Cunninghamia lanceolata)生态公益林9块固定样地的实测数据,选用土壤有机质、全氮、全磷、碱解氮、有效磷、速效钾、土壤容重和pH值8个指标对杉木林改造前后的土壤肥力进行了对比分析,并基于乘除法原理提出了土壤肥力综合评价指数和评价等级。结果表明:与改造前相比,改造后3个龄组杉木生态公益林0~20 cm表层土壤的有机质、全氮、全磷、碱解氮、有效磷、速效钾的含量都有不同程度的提高,且杉木幼、中林提高程度更明显,改造后的杉木幼、中龄林的土壤容重略有下降,pH值略有增加,但杉木近熟林的土壤容重和pH值基本保持没变。说明补植了阔叶树种栾树(Koelreuteria bipinnata)和马褂木(Liriodendron tulipifera)的杉木幼龄林和补植了阔叶树种栾树、马褂木和深山含笑(Michelia maudiae)的杉木中龄林土壤质量的改善程度明显优于在林下补植了红豆杉(Taxus chinensis)的杉木近熟林,通过树种结构调整改造后的3个龄组杉木林土壤肥力综合评价指数值也有不同程度的提高,土壤肥力质量从差变为较差。相比传统的土壤肥力综合评价指标,本文提出的土壤肥力综合评价指数不需要计算指标权重,计算量小,而且可以根据不同的土壤系统,对模型参数的个数适当增减,适用性较强。     

上海市公园绿地土壤肥力特征分析与综合评价

为提高城市绿地生态系统功能,了解上海全市的公园绿地土壤肥力整体状况,以上海全市16个行政区65个公园中87个绿地土壤(0～20 cm)为研究对象,测定土壤pH值、电导率(EC)、大量元素(氮、磷、钾)、中微量元素(镁、钙、硫、锰、铁和钼)等15项化学指标,通过单因子评价、综合评价法及GIS技术对公园绿地土壤肥力质量进行评价。结果表明,上海市公园绿地表层土壤整体呈碱性,EC值偏小,有机质、大量元素全量养分和速效养分大都处于中等水平,微量元素钼缺乏,其他元素含量充足;全氮和有效磷变异性强。上海市公园绿地土壤综合肥力质量整体呈中等水平,且空间上有北高南低的趋势;土壤肥力的限制因子主要为pH值、全氮、碱解氮、有效磷和有效钼,应采用改善土壤pH值、种植豆科植物、施用微肥等措施提高土壤肥力质量。     

我国水蚀区坡耕地土壤肥力现状分析

土壤肥力是土壤质量的重要组成部分,为探讨我国东部水蚀区坡耕地土壤肥力质量现状,以田块尺度为研究单元,选取36个采样点,测定11项土壤养分及肥力环境指标。应用主成分分析法,计算变量的Norm值,结合指标间的相关系数,确定有机质、全钾、pH值、CEC、粘粒含量进入土壤肥力评价的最小数据集(MDS)。采用"S"型或抛物线型隶属度函数计算指标隶属度并对单项肥力指标进行评价,利用综合指数模型计算各点土壤肥力综合指数(IFI)进行评价。结果表明:(1)CEC和粘粒含量隶属度值较低,是制约我国水蚀区坡耕地土壤肥力的重要因素;(2)各采样点土壤肥力综合指数变幅是0.17~0.72,平均值为0.44±0.15,属中等肥力水平。36个采样点土壤肥力综合指数等级属低、中、高的比例分别为27.8%,58.3%,13.9%,大多数采样点土壤肥力处于中等及以下水平;(3)6个水蚀二级分区的土壤肥力综合指数均值不存在显著差异,东北低山丘陵和漫岗丘陵区土壤肥力综合指数最高,而西北黄土高原区土壤肥力综合指数最低。研究结果对指导我国水蚀区坡耕地合理施肥和土地资源可持续利用具有重要意义。     

基于重金属污染的太原市小店污灌区土壤综合肥力质量评价

为了解太原市小店污灌区的土壤肥力质量,应用土壤重金属综合污染指数法将污灌区采样点分为3个区域,并按分区分别采用主成分分析法选取前两个主成分的6项理化性质作为评价指标,确定其相应权重系数,应用土壤肥力综合评价指标法定量评价分区土壤肥力质量。结果显示:污灌区土壤污染以安全等级为主,土壤肥力质量状况总体较好;北部地区土壤碱解氮和有效磷含量偏低,阳离子交换量尤其低;西南部地区除阳离子交换量偏低之外各项指标都属上等水平,土壤肥力质量良好;中部地区阳离子交换量和有效磷含量偏低。对3个区域而言,有机质均为重要的土壤肥力质量评价因子,土壤阳离子交换量与有效磷是土壤肥力质量的主要限制因子。3个区域均属一级土壤肥力水平,但不同区域的土壤肥力质量存在差异,污灌区西南部土壤肥力质量总体优于中部及北部地区,其中北部地区土壤肥力综合评价指标值最低。该结果可为污灌区土壤的精准施肥及科学管理提供参考依据。     

基于最小数据集的青藏公路沿线土壤质量评价

为明确青藏公路沿线土地土壤质量的基本特征,通过采集沿线3种不同土地利用类型(农地、草地和沙地)的土壤样品,采用主成分分析法(PCA,Principal Component Analysis)筛选最小数据集(MDS,Minimum Data Set)指标,并构建土壤质量指数(SQI,Soil Quality Index)定量评价其土壤质量。结果表明:(1)相较于农地和草地,沙地的土壤肥力较为贫瘠,其土壤有机质、全氮和有效磷的土壤肥力等级均为6级。9个土壤指标均为中低度敏感指标,沙地土壤黏粒和粉粒含量具有更强的空间分异性。(2)沿线土壤质量评价最小数据集由全钾、全磷、有机质、黏粒和粉粒组成,最小数据集能够较好地替代全数据集进行土壤质量评价(p<0.01)。(3)沿线农地的土壤质量指数SQI(0.535±0.043)高于草地SQI(0.499±0.044)和沙地SQI(0.449±0.066)。该研究发现沿线农地土壤质量为中等水平,沿线草地和沿线沙地土壤质量处于较低水平,土壤有机质是影响青藏公沿线土壤质量的主要因素。     

浙江低丘红壤肥力数值化综合评价研究

对 3 8个田间试验结果 ,选用 1 1项肥力指标进行 .根据作物效应曲线分别建立S型和抛物线型隶属度函数 ,并计算出隶属度值 .用多元统计中的因子分析方法 ,求得各肥力指标的权重值 .进一步求得土壤肥力综合指标 (IFI)和土壤养分肥力指标 (NFI) ,结果表明 ,IFI和NFI与玉米产量之间达到显著相关水平 ,说明综合评价结果能较好地反映土壤肥力状况     

基于最小数据集和模糊数学法的水旱轮作区土壤肥力质量评价

基于湖北省水旱轮作区133个土壤样点数据,利用主成分分析及参选指标相关关系法确定了该区域土壤肥力质量评价的最小数据集,分别为土壤有机质、碱解氮、速效磷、速效钾、有效硼、有效钼、有效锌。利用模糊数学隶属度函数法对该区域土壤肥力质量进行了评价,结果表明:湖北省水旱轮作区的赤壁、洪湖、荆州、麻城和沙洋5个市(区、县)的土壤肥力质量以中等(III)为主,差(Ⅳ)等级次之,其中赤壁市和沙洋县土壤肥力质量以良(II)等级的比例(12.5%和9.5%)大于其他县市,5个县市土壤肥力质量均无优(I)和很差(V)2个等级。     

土壤质量评价中文文献分析

基于中国知网(CNKI,http://www.cnki.net)1950~2016年关于土壤质量方面的中文文献查阅结果,概述了我国关于土壤质量的内涵认知、评价指标体系选择和权重确定方法以及土壤质量评价方法,旨在为今后的土壤质量评价提供参考。关于土壤质量的内涵,中国科研人员更接受土壤肥力和土壤质量这两个概念,进入21世纪后,中国开始更为关注基于"污染"的土壤环境质量;评价指标体系大致可以分为土壤物理指标、土壤养分和常规化学指标、土壤生物指标和污染物指标四类,土壤物理指标中,质地、含水量和耕层厚度使用频数最多,土壤养分与常规化学指标中,有机碳和pH使用频数最多,土壤生物指标中酶活性、细菌数量和真菌数量使用频数最多,但相比于物理指标和土壤养分和常规化学指标,生物指标的应用较少,污染物指标中重金属指标的使用频数最多;指标权重的确定方法中主观法的层次分析法和客观法的主成分分析占主导地位;土壤质量评价方法中综合指数法和内梅罗指数法应用的最多。土壤质量评价指标体系,因评价者、评价区域、评价对象和评价目的的不同而不同,随着我国经济、土壤微生物的研究技术的迅猛发展,预计微生物指标在土壤质量评价中将会得到越来越广泛和深入的应用。     

Hierarchical partitioning for selection of microbial and chemical indicators of soil quality

Statistical approaches, especially multivariate techniques such as hierarchical partitioning analysis (HP) and redundancy analysis (RDA), can be used to select appropriate variables for soil quality assessment. HP is usually applied to ecological data from plants and animals, but has not been applied to chemical and microbial properties such as those used as indicators of soil quality. Our aim was to show how these methods can be employed to find soil quality indicators, using soil microbiological, chemical and physical data to compare two forest types (native and reforested Brazilian Araucaria forests) in two locations in Southeast Brazil. We used RDA to investigate relationships among variables. Additionally, we quantified the independent effects of predictor variables: location, forest type, two specific seasons and some soil properties and used HP to examine how these environmental variables interact to influence soil microbial and chemical attributes. RDA showed that acid phosphatase and dehydrogenase activity, NO₂⁻ oxidizer numbers, basal respiration, metabolic quotient, pH, P and sand content were positive and significantly correlated with the native Araucaria forest, whereas arylsulphatase activity, denitrifier numbers, microbial biomass carbon, microbial quotient, TOC, S and clay levels were positively correlated with the reforested Araucaria. These preliminary results suggest that these variables are the best indicators of soil quality for Araucaria forests. However, HP, used as a complementary tool, showed that only dehydrogenase activity, pH and S variations were due more to forest type than to physical and chemical soil properties, and were resistant to the variation in the two seasons. Overall, our results indicated that dehydrogenase activity, pH and S are potential indicators that can be used to assess or monitor soil health in Araucaria forests. In conclusion, we demonstrated the usefulness of HP to find soil quality indicators. Similarly, other statistical methods, as RDA, could complement HP and increase the reliability of studies that consider simultaneous variables in soil science.     

Urbanization alters the functional composition,but not taxonomic diversity,of the soil nematode community

We evaluated the response of riparian forest soil nematode community structure to the physico-chemical environment associated with urban land use. Soils were sampled seasonally between December 2000 and October 2002 along an urban—rural transect in Asheville, North Carolina. We characterized the taxonomic (to genus) and functional composition (trophic groups) of the nematode community of forest soils, as well as several nematode ecological indicators (maturity index, channel index, weighted faunal index). The diversity of nematode genera was not affected by urban land use. However, there tended to be functional differences in the nematode communities along the land use gradient. The urban soils tended to have lower abundances of predatory and omnivorous nematodes. Differences in channel index scores indicated that there was less fungal dominance in the soil food webs of the urban soils. Our results indicate that the functional composition of the soil food web is an important component of soil biodiversity that can be affected by land use practices. This study was conducted in a relatively small city; hence the influence of pollutants on the soil environment was not as great as in larger cities. Correspondingly, the impact on the soil nematode community was not very severe. The utilization of the nematode community assemblage as an indicator of soil conditions should be further explored in urban places of differing magnitudes of environmental effects.     

Changes in soil quality due to introduction of broad-leaf trees into clear-felled Chinese fir forest in the mid-subtropics of China

Abstract. After clear-felling of a first generation Chinese fir ( Cunninghamia lanceolata ) forest, mixed stands of Chinese fir and Michelia macclurei (a broadleaf tree) (MCM), pure M. macclurei stands (PMS) and pure Chinese fir stands (PCS) were established in 1983. The effects on soil were evaluated 20 years after planting by measuring physicochemical, microbiological and biochemical parameters. Both broadleaf monoculture and mixtures of broadleaf and conifer exerted a favourable effect on soil fertility. A soil quality index (SQI) decreased in the order: PMS (0.62) > MCM (0.57) > PCS (0.41). Improvement in soil quality, enhanced biological activity and forest productivity demonstrated that mixed stands are an effective measure to maintain sustainable forest productivity, as well as to control soil degradation under successive stands of Chinese fir. In addition, since the microbiological and biochemical parameters measured were sensitive to the forest management, they may be potential indicators for assessing the sustainability of different management systems. The results also showed that total organic carbon, cation exchange capacity and microbial biomass carbon are effective indicators of the improvement or deterioration of soil quality under forest.     

Assessment of soil quality in different ecosystems (with soils of Podolsk and Serpukhov districts of Moscow oblast as examples)

The values of the soil-ecological index and microbiological parameters (the carbon of microbial biomass C_mic, its ratio to the total organic carbon C_mic/C_org, and basal respiration) were determined for the soddy-podzolic, soddy-gley, bog-podzolic, meadow alluvial, and gray forest soils under different land uses (forest, fallow, cropland, and urban areas) in the Podolsk and Serpukhov districts of Moscow oblast (237 and 45 sampling points, respectively). The soil sampling from the upper 10 cm (without the litter horizon) was performed in September and October. To calculate the soil-ecological index, both soil (physicochemical and agrochemical) and climatic characteristics were taken into account. Its values for fallow, cropland, and urban ecosystems averaged 70.2, 72.8, and 64.2 points (n = 90, 17, and 24, respectively). For the soils of forest ecosystems, the average value of the soil-ecological index was lower (54.4; n = 151). At the same time, the micro-biological characteristics of the studied forest soils were generally higher than those in the soils of fallow, cropland, and urban ecosystems. In this context, to estimate the soil quality in different ecosystems on the basis of the soil-ecological index, the use of a correction coefficient for the biological properties of the soils (the C_mic content) was suggested. The ecological substantiation of this approach for assessing the quality of soils in different ecosystems is presented in the paper.     

Soil quality assessments in integrated crop–livestock–forest systems: A review

Integrated crop–livestock–forest is a promising strategy to improve soil quality. It comprises four different integrated farming systems: crop–livestock, crop–forest, forest–livestock and crop–livestock–forest. This work systematically reviewed studies about integrated crop–livestock–forest systems and soil quality. A total of 92 papers were retrieved from the Web of Science—Clarivate Analytics platform, and the following information was analysed: publication year, institution, region of the studied site, type of integrated system, soil type, tillage system, maximum soil depth and the soil quality indicators assessed. Most studies were published in the second half of the 2010s. Brazil is a prominent focus of research about soil quality and integrated crop–livestock–forest systems, with significant contribution from its central and southern regions. The Embrapa was the main publishing institution, present in over one‐third of the studies. Crop–livestock was the most common integrated system, Ferralsols was the most common soil group, and most of the studied soils were clayey. No tillage was the main tillage system. Most studies focused on the topsoil, assessing physical and/or chemical soil quality indicators. More emphasis on biological indicators of soil quality is required, as well as assessments integrating biological, physical and chemical indicators of soil quality. Future works should compare different integrated systems, including assessments deeper in the soil profile, especially in systems with the forest component, and also in sandy and silty soils. Soil quality indicators that have been rarely used should be further tested. Novel indicators should be added to better understand the promotion of soil quality by integrated crop–livestock–forest systems.     

亚热带区域几种典型人工林生态系统林地土壤质量评价

针对不同经营模式对林地土壤的物理性质、化学性质和生物学性质的影响,采用主成分分析方法直观定量地研究了亚热带区域几种典型人工林生态系统林地的土壤质量指数和土壤退化指数,揭示了土壤质量指数之间的相关性和差异性、以及土壤退化指数之间的相关性和差异性,并很好地识别出了土壤质量指数和土壤退化指数的主要成分。分析结果基本上反映了不同生态类型林地土壤质量状况,主成分分析土壤质量指数得分以常绿阔叶林最高,其次是混交林和阔叶纯林,连栽杉木纯林最低;主成分分析土壤退化指数表明,与次生常绿阔叶林比较,其中连栽杉木纯林退化幅度最大,而混交林和阔叶纯林次之。从而对其林地土壤质量进行了准确评价,为杉木人工林的可持续利用提供直接依据,并为亚热带区域人工林生态系统林地土壤质量评价提供参考。     

黄土高原旱地土壤质量评价指标研究

基于设置在陇中黄土高原半干旱区的长期定位试验,运用综合评价模型,定量评价了小麦→豌豆双序列轮作系统6种不同耕作方式对土壤质量的影响。结果表明,采用加权综合法和加乘法则对土壤质量进行综合评价,能够较好地反映土壤质量的实际情况,敏感地反映耕作方式对土壤质量的影响。运用逐步判别分析法对6种不同耕作方式[传统耕作(T)、免耕作(NT)、传统耕作秸秆还田(TS)、免耕秸秆覆盖(NTS)、传统耕作地膜覆盖(TP)、免耕地膜覆盖(NTP)]下29项土壤属性指标进行筛选,建立了包括团粒结构、全氮、速效氮、有机质、蔗糖酶活性、作物产量、种植纯收益和产投比8项因子的简化评价指标体系。原始评价指标体系下2种轮作序列土壤质量指数排序均为NTSTSNTPNTTPT;简化评价指标体系下豌豆→小麦轮作序列土壤质量指数排序为NTSTSNTPNTTTP,而小麦→豌豆轮作序列土壤质量指数排序为NTSTSNTNTPTTP。进一步相关分析和方差分析表明,应用逐步判别分析法建立的简化指标体系具有较高的代表性,可适用于黄土高原半干旱区土壤质量评价。     

北京山区不同植被恢复类型土壤质量综合评价

[目的] 综合评价北京山区不同植被恢复类型土壤质量,并进一步确定影响土壤质量的关键因素,为该地区植被恢复与重建提供数据支撑。[方法] 以立地条件相近的侧柏纯林、油松纯林、侧柏油松混交林、侧柏针阔混交林、油松针阔混交林、落叶阔叶混交林和无林地(对照)为研究对象,测定14个土壤理化指标作为土壤质量评价的总数据集(TDS),采用主成分分析法(PCA)和Pearson相关性分析建立土壤质量最小数据集(MDS),利用线性(L)和非线性(NL)2种评分方法计算土壤质量指数(SQI)和一般线性模型(GLM)确定影响土壤质量的关键因素。[结果] 植被恢复后相较于无林地,土壤容重、砂粒含量下降,而有机质、全氮、全钾、速效氮、速效钾等土壤养分含量增加。筛选出的研究区土壤质量评价MDS指标为全氮、砂粒、全钾、pH、有效含水量。4种方法(SQI-LT、SQI-NLT、SQI-LM、SQI-NLM)下,不同植被恢复类型的SQI值排序均为落叶阔叶混交林＞侧柏针阔混交林＞油松纯林＞油松针阔混交林＞侧柏油松混交林＞侧柏纯林＞无林地,植被恢复后土壤质量显著提升。SQI-NLM的土壤质量评价方法在北京山区具有更好的适用性。相较于无林地,其他植被恢复类型的SQI-NLM分别提高64%,48%,45%,36%,33%,27%。GLM模型解释了土壤质量指数总变异的85.24%,植被类型对土壤质量指数的解释比例最大(45.09%)。[结论] 选择适宜的植被恢复类型是改善区域土壤质量的关键。未来实施植被恢复时,树种选择上优先考虑阔叶树种。造林配置方式的选择应取决于树种而定,如侧柏纯林中引入本土阔叶树种形成侧柏针阔混交林或选择油松纯林是最佳造林模式。     

土壤质量时空变化一体化评价方法及其应用

探讨了土壤质量时空变化一体化的评价方法 ,并以河北省曲周县一个 3 3km2 的小区为例 ,对 1980年与 1999年两个时段的 8个单项土壤质量指标和土壤综合质量指标的时空变化进行了定量化评价。结果表明土壤质量指数法与GIS技术相结合 ,可以很好地表示土壤质量的时空变化。文章还讨论了该方法的适用范围。