滇中高原主要森林土壤发生特性及系统分类

为明确滇中高原主要森林土壤系统分类地位,并为云南森林土壤合理利用提供科学依据,本文以中国土壤系统分类为基础,研究了滇中高原8个典型土壤的剖面特征和发生性状,通过分析土壤发生特性,划分其诊断层和诊断特性,对土壤进行系统分类。结果表明:不同土壤剖面发育层次较明显,且均发育有淀积层,土体颜色以暗棕色和紫色为主,质地为偏砂质黏壤土;砾石含量在0.7%~42.4%之间,粘化率在0.53~2.56之间,淋溶作用较强。有机质含量在32.87~208.14g/kg之间,CEC含量在4.75~49.36cmol/kg之间,盐基离子以Mg^2+、Ca^2+为主,盐基饱和度在6.27%~90.74%之间;铁游离度在41%~95%之间。土壤风化程度一般,大部分剖面处于脱硅富铁铝化阶段。8个土壤剖面具有2个诊断表层、3个诊断表下层和6个诊断特性。8个土壤剖面(黄棕壤、山地红壤、紫色土)在发生分类上划分为3个土纲分别为淋溶土、铁铝土、初育土。在土壤系统分类方案中检索出3个土纲,3个亚纲,3个土类,3个亚类,分别为铁质干润雏形土、粘化干润富铁土、简育干润富铁土、铁质干润淋溶土。     

太白山土壤特性及氧化铁发生学特征

随海拔的降低,秦岭北坡中山区森林土壤因温度、降水和植被类型的变化存在很大差异:高海拔地区发育的酸性湿润雏形土酸度较高,有机质含量十分丰富;与之相比,低海拔地区发育的简育湿润淋溶土有机质含量下降,但结构复杂,土壤具有粘化层。较高的有机质含量和特殊的有机质组成促进了纯针叶林土壤中硅酸盐矿物的溶解,释放出氧化铁并使之螯迁至土壤B层富集。环境因素决定了土壤酸度、有机质等特性,也影响土壤氧化铁的组成和分布。土壤粘粒含量与土体游离氧化铁含量显著相关,剖面铁的游离度与氧化铁全量无关,只与土壤发育程度有关。太白山北坡中山区土壤处于脱盐基富硅铝化的风化发育阶段     

海南岛尖峰岭地区山地土壤发生特性

对地处热带的海南岛尖峰岭地区的山地土壤的发生和发育特性进行了研究。因母岩因素以及较弱的成土作用和较强的侵蚀作用 ,土壤质地普遍较粗 ,石砾含量高。由于山地气候的垂直分异 ,不同海拔高度土壤间的发生特性存在较大差异。高海拔地区土壤易风化矿物含量高 ,低海拔地区土壤中抗风化能力强的锆石含量高 ;高海拔区土壤中粘土矿物以三水铝石和埃洛石为主 ,含有一定量的铝蛭石 ,低海拔土壤以高岭石为主 ,有一定量的水云母。伴随海拔高度的增加 ,阳离子交换量 (CEC7)、盐基总量、盐基饱和度、pH下降 ,而代换性酸H 、Al3 却逐渐增多。高海拔区湿润的水分状况和酸性成土环境导致粘粒的硅铝率、硅铁铝率较低海拔土壤小。尖峰岭地区土壤类型以雏形土为主 ,山麓分布有淋溶土。     

有效硅在土壤中的含量分布及影响因素——以河南信阳地区土壤为例

根据不同母质发育的土壤，采集了水稻土耕层样８６个，旱地耕层样４３个。土壤剖面样１７个，有效硅测定方法：用ｐＨ４的１ｍｏｌ／ＬＮａＯＡＣ－ＨＡＣ为提取剂，加显色剂后，用分光光度计测定含量。有效硅总的趋势是酸性岩及其变质岩发育的土壤低于沉积岩的含量；第四纪沉积物中，Ｑ４低于Ｑ２时期的含量。在相同气侯条件下，成土母质和粘粒含量是影响有效硅含量的主要因素     

有效硅在土壤中的含量分布及影响因素

根据不同母质发育的土壤，采集了水稻土耕层样８６个，旱地耕层样４３个。土壤剖面样１７个，有效硅测定方法，用ｐＨ＝４的１ｍｏｌ／ＬＮａＯＡＣ－ＨＡＣ为提取剂，加显色剂后，用分光光度计测定含量，有效硅总的趋势是酸性岩及其变质岩发育的土壤低于沉积岩的含量；第四纪沉积物中，Ｑ４低于Ｑ２时期的含量。在相同气候条件下，成土母南和粘粒含量是影响有效硅含量的主要因素。     

试论伏牛山南坡土壤垂直分异规律——兼论亚热带北界的划分

在野外土壤调查和室内土壤理化分析的基础上,开展了伏牛山南坡土壤组成和性质垂直分异、土壤类型划分以及亚热带北界问题的讨论。研究表明：(1) 调查断面上土壤表层HA/FA随高度增加而增大,且均小于1,海拔900 m左右土壤胡敏酸的芳构化程度最低;随高度增加土壤pH和盐基饱和度先下降后上升;海拔900 m以下的土壤中均有明显的黏化层,向上土壤黏粒淋溶淀积逐渐减弱;海拔900 m以下的土壤土体风化程度高,大部分氧化物的平均迁移系数和土体淋溶率小于1,土体Saf小于5.06,淀积层游离铁含量大于20 g·kg-1,铁游离度大于40%,具有弱富铁铝作用,剖面中出现明显的铁锰新生体,而向上土体风化程度减弱,不发生富铁铝作用,剖面中不出现铁锰新生体。(2) 伏牛山南坡海拔550 m以下出现黏磐黄褐土 (饱和黏磐湿润淋溶土),550~950 m出现普通黄棕壤 (普通铁质湿润淋溶土),950~1900 m出现棕壤 (普通简育湿润淋溶土或暗沃简育湿润雏形土),1900 m以上出现暗棕壤性土或草甸暗棕壤 (暗沃冷凉湿润雏形土)。(3) 伏牛山南坡亚热带北界约在海拔950 m。     

海南岛北部玄武岩上土壤发生的化学特性研究

海南岛北部不同时期喷发的玄武岩上发育的土壤构成一个风化成土时间系列。对这一土壤系列的化学特性研究表明，随风化成土时间的增加，pH值不断下降，但至富铁土后，pH趋于稳定，而土壤CEC7，盐基饱和度下降。同时，土体中Al2O3、Fe2O3、TiO2含量增加，而Ca、Mg、K、Na淋失强烈，SiO2含量也不断降低。以土壤中大量元素含量为基础计算多数指标难以反映热带地区碱金属和碱土金属元素迅速而强烈淋失的成土风化过程。常用的土体分子硅铝率和硅铁铝率并不能指示所有土壤的风化成土作用程度。     

3种水稻土时间序列黏粒矿物的组合特征与物源指示意义

对南方丘陵区3种不同母质水稻土时间序列黏粒矿物的X-射线衍射（XRD）进行分析发现：① 紫色砂页岩（PS）母质起源土壤的黏粒矿物以高岭石类似矿物为主;第四纪红黏土（RC）母质起源土壤的黏粒矿物以高岭石类似矿物、伊利石类似矿物与三羟铝石为主;红砂岩（RS）母质起源土壤的黏粒矿物以1.4 nm过渡矿物、高岭石类似矿物与三羟铝石为主。② 这3种母质土壤种稻后黏粒矿物的变化大体可分为2种情况。RC与RS母质的起源土壤种稻后,土壤黏粒矿物的变化相对较小,伊利石类似矿物相对含量有所增加,这可能主要与钾肥的持续施用有关。PS母质的起源土壤种稻后,土壤黏粒矿物变化相对较大,表现为高岭石类似矿物相对含量降低,低结晶度的伊利石或次生绿泥石与三羟铝石相对含量上升。PS母质发育的土壤种稻后脱钾明显且主要集中在原生矿物部分。这种原生矿物的脱钾作用对土壤黏粒含量和黏粒矿物的类型都有较大影响。③ 起源土壤的黏粒矿物通常会被水稻土所继承,并在水稻土发育过程中相对稳定,可以用其来指示起源土壤（或母质）的物源组分。     

南极菲尔德斯半岛地区土壤中主要元素的迁移与富集

对 Si、Al、Fe、Ca、Mg、Mn、K、Na和 P等元素在南极菲尔德斯半岛地区三个代表性土壤剖面 (不饱和寒冻雏形土、纤维质寒冻有机土和鸟成土 )中的迁移与富集规律进行了研究 ,结果表明 ,本区土壤中物质移动和元素迁移现象明显 ;几种主要元素在不同类型土壤以及同一土壤不同层次中的移动行为有显著差异 ,土壤自由水状况和地表生物活动在元素迁移与富集过程中发挥重要作用。另外 ,在土壤发育和土壤粘粒形成过程中 ,不同元素在不同土壤颗粒之间的再分配现象存在较大差异。     

甘肃河西西部地区土壤矿质成分的分布及其变异

本文通过对土壤剖面中的矿物质成分分析,计算出了各土类间元素含量的变异系数。结果表明,各土类的烧失量、CaO的高变异,烧失量、CaO和MgO三者的相对比例,硅铝铁分子比率及风化淋溶系数等,反映了该区土壤形成特点及发育程度。     

暴雨对土壤组成和性质的影响——以河南省泌阳暴雨中心区为例

本文以河南省泌阳暴雨中心区为例 ,在野外土壤调查和室内理化分析的基础上 ,分析讨论了暴雨对土壤组成和性质的影响。结果表明 ,暴雨中心区土壤因长期的暴雨冲刷 ,土层浅薄 ,发生层数目少 ,土体构型简单 ;砾石含量高 ,物理性粘粒含量低 ,质地类型多属多砾质砂土 ;土体中不出现肉眼可辨的铁锰结核 ;土壤淋溶作用强烈 ,呈微酸性反应 ;土壤有机质和速效氮含量较高 ,而速效钾含量偏低 ,有机质表聚化现象不明显 ;盐基淋溶率小于 1 0 0 ,土体SiO2 /R2 O3小于 7 0 0 ,脱硅和富铁铝化作用明显 ,土体风化程度较高。对暴雨中心区附近的土壤来说 ,上述土壤组成和性质均出现明显的差异。     

哈尔滨沙尘暴的化学特征及其物质源探讨

对哈尔滨2002年3月20日的沙尘沉降物进行了收集。地球化学元素分析表明,哈尔滨沙尘暴沉降物化学成分以SiO2、Al2O3和Fe2O3为主,三者之和达77.8%,比兰州沙尘暴沉积物高8.72%,比兰州黄土高7.06%。V、Rb、Nb、Ba等微量元素含量要明显高于兰州沙尘,而Ni、Cu、Pb、Zn、As、Sr则低于兰州沙尘。Ca、Na、Sr元素的富集因子明显小于1,为亏损元素;Mg、K、Si、Fe、Mn、P、Ti、Co、Ni、V等元素的富集因子都在1左右,主要是地壳来源,来源于地表土的风力起尘。Cu、Pb、Zn、Cr、Se等元素有一部分来自于地壳源之外的其他污染源;As、Cd和Sb元素的富集因子大于10,为大气污染来源。沙尘的化学组成及富集因子、判别函数、物源指数、地表土的粘粒率、化学风化指标等分析表明,西北黄土的元素组成非常接近兰州沙尘,而明显不同于哈尔滨沙尘,哈尔滨沙尘源区不同于西北黄土及兰州沙尘,其气候生物状况和化学风化程度要明显好于或高于西北沙尘源区。     

岩溶山区不同植被群落土壤生态系统特性研究

自然植被演替成为次生植被、人工林或人工开垦利用后,岩溶山地土壤物理性能退化;沙化现象明显;坡耕地土壤长时间持水供水性能、抗旱性能降低;土壤种子库中草本种子比例大,木本植物种子少,土壤种子库退化更严重。研究区土壤有机质和全N受植被类型和土地利用强度影响明显,坡耕地土壤有机质较林草地系统低,退耕还林还草后,土壤有机质含量稳定增加。与自然植被相比,人工林、次生林系统土壤有机质含量仍较低。从弃耕地→灌草坡→次生林地的演替过程中,土壤种子库生态优势度呈降低趋势,物种丰富度和多样性增加。研究结果认为,岩溶生态系统土地退化的实质是土壤作为水库、养分库和土壤种子库功能的差异退化。     

天津市不同土地利用类型土壤中多环芳烃的含量特征

本文分析了天津不同土地利用类型表层土壤若干多环芳烃组分的含量特征及污染水平。结果显示,城市绿地土壤中多环芳烃的含量最高,污灌农田土壤中一些组分的含量也较高,但多数组分与普通农田、荒地等其他土地利用类型相差不大;在6种土地利用类型中,低环/高环在大部分地区小于1,说明天津地区多环芳烃污染主要以燃烧源为主。芘/苯并(a)芘参数值则反映出市区绿地土壤受交通污染的影响比较大;各种土地利用类型土壤表层均受到了一定程度的多环芳烃污染,其中城市绿地土壤污染程度较为严重     

Copper content and its distribution in soils of Tibet

The copper (Cu) content in 205 soil samples (0-20 cm) of Tibet, covering 5 soil classes, were analyzed. The results showed as follows: (1) the average content of Cu was 19.6 mg kg-1 (CV=49.28%); (2) the content of Cu in Tibetan soils was lower than the average level of China; (3) the content of Cu gradually decreased from the southeast to the northwest which was consistent with the direction of changes in the zonal successions of soil in Tibet; (4) Cu contents in Tibetan soils varied with soil properties, particularly soil parent materials that Cu contents were remarkably enriched in soils derived from shale materials.     

云南保山西庄河流域森林土壤磷吸附特性

本实验测定了云南省保山地区西庄河流域几种森林土壤对磷的等温吸附。实验结果表明，供试土壤对磷的吸附很的拟合了Langmuir等温吸附曲线。土壤母质对磷的吸附影响很大，磷吸附量依次是页岩＞石灰岩＞砂岩。土壤中铁、铝含量是影响磷吸附量遥最重要和最直接的因素，其它土壤特性也通过影响铁、铝的含量或者铁铝氧化物的活性而间接影响土壤的磷吸附量。相关分析表明，供试土壤磷饱和吸附量与活性Fe^3 、Al^3 、全氧、有机质含量分别呈正相关，其相关系数分别是0．6215、0．6853、0．6855和0．6819；而与土壤pH、Ca62 含量、交换性盐基离子含量和直离子饱和度呈负相关，其相关系分别是－0．7366、－0．6802、－0．6383和－0．8730，都达到了1％的显著水平。     

Copper content and its distribution in soils of Tibet

The copper (Cu) content in 205 soil samples (0–20 cm) of Tibet, covering 5 soil classes, were analyzed. The results showed as follows: (1) the average content of Cu was 19.6 mg kg^-1 (CV=49. 28%); (2) the content of Cu in Tibetan soils was lower than the average level of China; (3) the content of Cu gradually decreased from the southeast to the northwest which was consistent with the direction of changes in the zonal successions of soil in Tibet; (4) Cu contents in Tibetan soils varied with soil properties, particularly soil parent materials that Cu contents were remarkably enriched in soils derived from shale materials.     

Integrating soils and geomorphology in mountains—an example from the Front Range of Colorado

Soil distribution in high mountains reflects the impact of several soil-forming factors. Soil geomorphologists use key pedological properties to estimate ages of Quaternary deposits of various depositional environments, estimate long-term stability and instability of landscapes, and make inferences on past climatic change. Once the influence of the soil-forming factors is known, soils can be used to help interpret some aspects of landscape evolution that otherwise might go undetected.The Front Range of Colorado rises from the plains of the Colorado Piedmont at about 1700 m past a widespread, dissected Tertiary erosion surface between 2300 and 2800 m up to an alpine Continental Divide at 3600 to over 4000 m. Pleistocene valley glaciers reached the western edge of the erosion surface. Parent rocks are broadly uniform (granitic and gneissic). Climate varies from 46 cm mean annual precipitation (MAP) and 11 °C mean annual temperature (MAT) in the plains to 102 cm and −4 °C, respectively, near the range crest. Vegetation follows climate with grassland in the plains, forest in the mountains, and tundra above 3450 m. Soils reflect the bioclimatic transect from plains to divide: A/Bw or Bt/Bk or K (grassland) to A/E/Bw or Bt/C (forest) to A/Bw/C (tundra). Corresponding soil pH values decrease from 8 to less than 5 with increasing elevation. The pedogenic clay minerals dominant in each major vegetation zone are: smectite (grassland), vermiculite (forest), and 1.0–1.8 nm mixed-layer clays (tundra). Within the lower forested zone, the topographic factor (aspect) results in more leached, colder soils, with relatively thin O horizons, well-expressed E horizons and Bt horizons (Alfisols) on N-facing slopes, whereas soils with thicker A horizons, less developed or no E horizons, and Bw or Bt horizons (Mollisols) are more common on S-facing slopes. The topographic factor in the tundra results in soil patterns as a consequence of wind-redistributed snow and the amount of time it lingers on the landscape. An important parent material factor is airborne dust, which results in fine-grained surface horizons and, if infiltrated, contributes to clay accumulation in some Bt horizons. The time factor is evaluated by soil chronosequence studies of Quaternary deposits in tundra, upper forest, and plains grassland. Few soils in the study area are >10,000 years old in the tundra, >100,000 years old in the forest, and >2 million years old in the grassland. Stages of granite weathering vary with distance from the Continental Divide and the best developed is grus near the sedimentary/granitic rock contact just west of the mountain front. Grus takes a minimum of 100,000 years to form.Some of the relations indicated by the soil map patterns are: (1) parts of the erosion surface have been stable for 100,000 years or more; (2) development of grus near the mountain front could be due in part to pre-Pennsylvanian weathering; (3) a few soil properties reflect Quaternary paleoclimate; and (4) a correlation between soil development in the canyons and stream incision rates.     

Soil Property Differences Between Invaded Casuarina (Casuarina equisetifolia L.) Sites and Non-Casuarina Sites in the Bahamas

Casuarina (Casuarina equisetifolia) is a problematic invasive species within the Bahamas, associated with numerous environmental problems. Previous studies suggest casuarinas establish ecologically sterile monocultures, yet there is limited research on whether soils from casuarina-dominated sites differ physically or chemically from comparable soils under native vegetation. Because of the lack of knowledge and because this invader has the potential to be detrimental to native ecosystems, we conducted a study to examine differences in soil properties between sites where casuarinas dominated versus sites where casuarinas were absent. Soils at casuarina-dominated sites had lower potassium, phosphorus, and organic matter concentrations and had lower pH levels. But, casuarina-dominated sites had significantly higher leaf-litter abundances. No significant differences between soils were detected for calcium concentrations, magnesium concentrations, cation exchange capacity, nitrate-nitrogen concentrations, or soil moisture levels. A multivariate ordination showed that casuarina-dominated soils were more similar to one another than to non-casuarina soils. Thus, soil characteristics from casuarina-dominated areas appear to differ from comparable habitats devoid of casuarinas. There are at least two possible explanations: certain soil properties may have been more conducive to casuarina invasions, or casuarinas may have modified their soils once they became established. The results of this study provide insights into the invasion process and add to our understanding of how these invaders affect native Bahamian ecosystems.