塔里木盆地柽柳灌丛沙堆盐分分布特点研究

为明确处于稳定阶段柽柳灌丛沙堆内土壤盐分的分布规律及其对环境可能产生的影响,以塔里木盆地北缘洪积冲积扇末端为研究区,分析了灌丛沙堆内与堆间地盐分的分布特征及其与柽柳灌丛凋落物年产量的关系.研究结果表明,柽柳灌丛沙堆表层土壤(0-30 cm)盐分明显低于堆间地表层土壤盐分,相关分析表明,柽柳灌丛凋落物产量的增加是抑制盐分表聚的一个重要因素.而沙堆深层土壤(30-120 cm)盐分则明显高于堆间地相同深度的土壤盐分,呈明显的富集状态,即形成了明显的“盐岛”.盐岛内主要富集K+,Na+,C1和HCO3-这4种离子,其余离子(SO24-,Ca2+,Mg2+)则呈均匀分布或随机分布.以上结果表明,柽柳灌丛沙堆是土壤盐分局部汇集的小型盐分库,它的演变趋势会对干旱区绿洲生态系统的稳定性产生潜在的影响.     

几种一年生盐生植物的吸盐能力

【目的】土壤盐渍化在新疆发生面积多,分布广,利用盐生植物对盐分的超富集能力,选育生物量大且体内盐分浓度高的品种,可有效改良盐碱地。本试验比较了几种主要盐生植物的吸收离子类型和盐分积累量,为科学合理利用盐生植物进行盐碱地改良提供科学依据。【方法】选取一年生盐角草(Salicornia europaea)、盐地碱蓬(Suaeda salsa)、高碱蓬(Suaeda altissima)和野榆钱菠菜(Atripex aucheri Moq.)为材料进行人工种植,试验地土壤为壤土和砂壤土,耕层土壤盐分均值为10.23 g/kg,p H为8.36,属于中度盐化土壤。采用完全随机排列设计,在生育早期、中期和末期采样测定植物地上、地下部分干物质量和K+、Na+、Ca2+、Mg2+、Cl-、SO2-4浓度。【结果】生育末期四种盐生植物地上生物量均占整株生物量的89%以上,高碱蓬(23302 kg/hm2)蓬野榆钱菠菜(20379 kg/hm2)盐地碱蓬(18670 kg/hm2)盐角草(9096 kg/hm2)。盐分总浓度盐角草(215 g/kg)盐地碱蓬(152 g/kg)高碱蓬(137 g/kg)野榆钱菠菜(103 g/kg)。不同植物离子含量不同,K+浓度以高碱蓬中最高,Na+、Cl-、SO2-4在盐角草中最高,Ca2+、Mg2+浓度在盐地碱蓬中最高;4种盐生植物对Na+、Cl-、SO2-4的吸收能力极强,按阴离子类型划分盐角草属于SO2-4-Cl-型盐生植物,盐地碱蓬、高碱蓬、野榆钱菠菜属于Cl--SO2-4型盐生植物;盐分积累量为高碱蓬(3499 kg/hm2)盐地碱蓬(3061 kg/hm2)蓬野榆钱菠菜(2180 kg/hm2)盐角草(2080 kg/hm2)。【结论】盐生植物对土壤的改良效果主要以生育末期刈割时单位面积从土壤中吸收的盐分总量来衡量,这取决于此时地上部分生物量与植株体内盐分浓度的大小。植物会根据其生长需求选择吸收土壤中矿物质元素,盐角草对的Na+、Cl-的吸收能力强于盐地碱蓬、高碱蓬和野榆钱菠菜,尤其对Cl-表现出极强的选择吸收能力。     

小叶碱蓬和白麻土壤—叶片生态化学计量学特征对不同盐生境的响应

[目的] 分析干旱区盐生植物生境土壤与叶片生态化学计量特征在不同盐生境下变化趋势及主要限制因子,为研究干旱区盐生植物生长发育过程中养分限制因子和适应机制提供基础研究资料,同时为荒漠植物的生态保育和恢复提供参考。[方法] 选取艾比湖湿地国家级自然保护区稀盐盐生植物小叶碱蓬(Suaeda microphylla)和拒盐盐生植物白麻(Apocynum pictum),测定其生境土壤pH值、含水量、盐分、速效磷、铵态氮、有机碳、全氮、全磷以及植物叶片有机碳、全氮、全磷,分析两种植物叶片与生境土壤生态化学计量特征的关系,探究植物叶片生态化学计量特征的土壤限制因子。[结果] ①随着盐分增加,两种植物生境土壤磷下降,有机碳、氮及化学计量比呈上升趋势,土壤养分含量受盐渍化程度影响显著; ②两种植物叶片氮受土壤盐分影响显著,随盐分降低呈下降趋势,与土壤氮含量的变化趋势一致,叶片N/P平均值均小于14,表明研究区两种植物均受土壤氮含量限制; ③RDA分析表明,影响小叶碱蓬叶片生态化学计量的主要因子为土壤pH值(p=0.034)、含水量(p=0.002),而白麻主要受土壤磷(p=0.002)、铵氮(p=0.048)影响。[结论] 不同类型盐生植物在土壤—植物生态化学计量特征耦合关系上存在差异。稀盐盐生植物小叶碱蓬主要受土壤pH值、含水量的影响,拒盐盐生植物白麻主要受土壤磷、铵态氮含量影响。     

河北省滨海盐碱地土壤与盐生植物养分特征的研究

对滨海盐碱地土壤和植物样品分析结果表明,生长不同盐生植物的土壤含盐量不同,以生长白刺(Nitraria sibirica Pall.)的土壤含盐量最高,达18.5 g/kg,盐地碱蓬(Suaeda salsa L.Pall.)次之,柽柳的最低。盐生植物的生长改变了土壤养分特征,4种生长盐生植物的土壤养分含量均高于光板地,土壤有机质含量增加44％以上,生长木本盐生植物白刺、柽柳(Tamarix chinensis Lour.)的土壤养分含量高于生长草本盐生植物碱蓬、碱茅(Puccinellia distans Jacq.Parl.)的土壤,且不同盐生植物养分特征不同,白刺、柽柳N和P含量均高于盐地碱蓬、碱茅,K含量则与植物耐盐特性有关。     

民勤绿洲盐生草生境土壤盐分特征及离子组成

对民勤绿洲盐生草周围不同距离范围内的总体盐分状况、盐分离子组成及离子之间的相关性进行了研究。结果表明,盐生草具有一定的聚盐作用,在其周围形成了一定的"盐岛"效应。在距盐生草0-60 cm范围内,土壤剖面中的土壤盐渍化程度随土层的加深而加重,土壤阴离子主要有Cl^-和SO₄^2-,阳离子主要有Na⁺和Ca²⁺,土壤盐分主要是氯化钠、氯化钙、硫酸钠和硫酸钙,其次是氯化镁和硫酸镁。其中在盐生草周围0-40 cm范围内,垂直剖面0-20 cm土层土壤全盐含量为0.98~1.52 g/kg,属于非盐渍化土壤,20-40 cm土层土壤全盐含量达到了2.25~2.30 g/kg,属于轻度盐渍化土壤,40-60 cm土层土壤全盐含量达到了3.10~3.16 g/kg,属中度盐渍化;在距盐生草60 cm处,垂直剖面0-40 cm土层土壤全盐含量为0.83~1.86 g/kg,属非盐渍化,40-60 cm土层土壤全盐含量达到了2.43 g/kg,属轻度盐渍化。除HCO₃^-外,土壤盐分含量与各盐分离子之间均呈极显著正相关。     

黄河三角洲不同长势柽柳对土壤水盐异质性的影响

柽柳是黄河三角洲主要的建群树种，维持其健康生长是滨海盐碱地生态修复的重要途径，而土壤水盐状况是影响柽柳生长的关键因素。本研究在黄河三角洲选定长势较差（N1）和较好（N2）的2处天然柽柳林，对比分析两处地下水状况、土壤含水率、盐分富集率及Cl-、Na+的时空变化。结果表明：① N2地下水平均埋深和矿化度都大于N1。② 雨季时N2土壤含水率高于N1，旱季则相反，尤以内围区（0 ~ 30 cm）更明显。③ 两地土壤盐分皆随深度递减，在雨季和旱季分布呈“盐谷”和“盐岛”特征，且N2的盐谷效应强于N1。④ 雨季时N2内围区（0 ~ 30 cm）Cl-、Na+含量整体低于外围区（30 ~ 90 cm），呈“左-右”空间分异，而N1呈“上-下”空间分异，再次说明N2雨季盐谷效应更强。综上，柽柳形成“盐谷/岛”效应是其适应高盐环境的重要策略。因此，通过柽柳适生种植，促进柽柳冠层生长以增强盐谷/岛效应是确保柽柳群落恢复和稳定的有效措施，有利于加快土壤盐渍化的修复，对湿地生态修复工程具有指导意义。     

民勤绿洲盐生草周围土壤盐渍化类型及其盐分离子相关性研究

以民勤绿洲广泛分布的盐生植物盐生草为研究对象,对其周围不同距离范围内土壤盐渍化类型及盐分离子的相关性进行研究。结果表明:在距盐生草水平方向0—60cm范围内,从阴离子组成来看,0—40cm土层土壤盐渍化类型为氯化物—硫酸盐型,40—60cm土层土壤为硫酸盐—氯化物型;从阳离子组成来看,0—40cm土层土壤盐渍化类型为钙钠盐型,40—60cm土层土壤为钠盐型。同时盐生草周围土壤(0—60cm)盐分离子之间的Pearson相关分析结果和偏相关分析结果存在明显差异,其中偏相关分析相对能够更准确地反映多元变量其中两个变量之间的相关性,建议在研究类似盐分离子之间的相关性时采用偏相关分析。试验区盐生草周围土壤盐分离子的偏相关分析表明:距盐生草20,40cm处,与土壤全盐含量相关性最高的阴阳离子分别为SO2-4,Na+;距盐生草60cm处,与土壤全盐含量相关性最高的阴阳离子分别为Cl-,Na+。可见,在盐生草周围土壤(0—60cm)中,土壤盐分主要是氯化钠、氯化钙、硫酸钠和硫酸钙。     

银川平原草甸湿地盐土及其盐分分布特征

通过野外观测和室内分析,研究银川平原草甸湿地盐土及其盐分的分布特征,根据土壤表层全盐含量将研究区土壤划分为5个等级,分别为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ,不同土壤等级的植被类型不同,在土壤Ⅰ中主要分布盐生草本草甸和盐生小灌木草甸,在土壤Ⅱ中主要分布盐生草甸和丛生禾草草甸,在Ⅲ、Ⅳ中主要分布根茎禾草草甸,在Ⅴ中主要分布杂类草草甸和一些低湿草甸;研究区草甸土壤全盐含量在垂直方向上表现出明显的表聚现象,在0~30 cm土层,随着土壤深度的增加,土壤全盐含量急剧下降,在30~70 cm土壤全盐含量的下降则较为平缓;各盐分离子除了HCO_3~–以外,其余各离子均表现出明显的表聚现象,但在不同的土壤等级中,只有Na~+、K~+、Cl~–和土壤全盐的表现一致,均为ⅠⅡⅢⅣⅤ。草甸湿地植物体中也有一定的盐分累积,在植物体中,主要盐分为NaCl、NaHCO_3;在土壤中主要盐分为NaCl、NaHCO_3、Na_2CO_3。     

不同土壤条件下荒漠盐生植物根际盐分特征研究

新疆是我国最干旱、盐渍化土壤分布面积最广、土壤积盐最重的地区[1]。这里特定的自然环境条件下发育着丰富的盐生植物,是中国盐生植物种类最多、分布最广的区域[2]。1995年,Breckle将盐生植物分成三个类型:泌盐盐生植物、稀盐盐生植物(肉质化盐生植物)和拒盐盐生植物(假盐生植物)[3]。这三种类型的盐生植物在干旱区盐生荒漠上均有广泛的分布。根际是土壤一植物生态系统物质交换的活跃界面[4]。目前,国内外对盐生植物的研究,多是集中在盐分对植物地上部分的形态、生理特征以及种子萌发等方面的影响[5],而对于盐生植物根际土壤的化学特征,以…     

利用耐盐植物改善盐土区农业环境

耐盐植物具有特定的抗盐性，有泌盐、稀盐、拒盐、耐盐等多种多样对盐渍生境的适应方式。全球盐生植物约有1560多种，中国有502种。许多耐盐植物有重要的经济价值。可以广泛用于食品、纺织、酿造、建筑、医药、化工等方面。更重要的是其对改良土壤、调节气候、维护生态平衡的环境效茄。种植耐盐植物增加地面覆盖，减少土壤蒸发，吸收带走土壤中的盐分。从而减少耕作层盐分累积。同时增加土壤有机质，改善土壤理化性状，促进对盐土有效改良和利用；还町以降低噪音、净化空气、减少温差、增加雨量、减少地表风蚀和十热风危害。通过引进、驯化、筛选、辐射诱变、多倍体育种等手段，我国已经选育出经济价值高、有应用价值的耐盐植物150种。本文简要介绍了这些耐盐植物对盐土的改良效果和经济利用价值。     

Soil‐vegetation relationships of three arid land plant species and their use in rehabilitating degraded sites

It is essential to consider soil characteristics when establishing vegetation in arid lands. In this study, the redundancy analysis (RDA) ordination method was used in this study to evaluate the habitats of Halocnemum strobilaceum, Limonium iranicum and Tamarix passerinoides growing in the Sejzy region, east of Isfahan. The study area was stratified into six ecologic‐floristic complexes. Stratified random sampling was then employed to collect soil and vegetation data from 1‐ha quadrats on nine sites. The soil samples were analysed to determine the characteristics of the soil in which the three species grew and to examine the soil profiles up to a depth of 2 m. Soil analyses revealed that high amounts of gypsum, silt, clay, saline, alkali and sulphate in the soil constituted a favourable habitat for Halocnemum strobilaceum. However, the per cent of silt and sulphate concentration in deep layers were negatively correlated with the growth of this species. Evaluation of the L. iranicum habitat revealed that the amounts of carbonate and CCE in the topsoil were positively correlated with the establishment and growth of the species but salinity and alkalinity were negatively correlated. The primary soil characteristics that positively influenced T. passerinoides included the presence of organic matter and bicarbonate ions in the soil layers and the total Ca and Mg content of the topsoil. However, Na was negatively correlated with Tamarix species. Determination of the soil characteristics that are associated with each of these xerophytic species can be used to determine which species is suitable for rehabilitating degraded sites in the study area. Copyright © 2010 John Wiley & Sons, Ltd.     

不同质地土壤中荒漠灌木梭梭“肥岛”的初步探讨

为检验荒漠灌木"肥岛"是否受土壤质地调节,本研究选取了中亚干旱区梭梭(Haloxylon ammodendron(C.A.Mey.))的两种原生生境:古尔班通古特沙漠的风沙土和绿洲区的灰漠土。两种土壤的质地有显著差异,风沙土中砂粒含量是灰漠土的2.1倍~2.4倍,而灰漠土中粉粒和黏粒含量分别是风沙土的3.0倍~3.6倍、2.9倍~5.1倍。通过对比分析两种土壤中梭梭冠下水分和养分的空间变异特征,获得了如下结果:两种土壤中均存在灌木"肥岛"效应,且随深度增加而减弱;在0~20 cm土层,与灰漠土相比,风沙土中冠下水分和养分的空间异质性更强,富集程度更高,风沙土中水分、有机质、有效氮和有效磷的富集率分别是灰漠土的4.6倍~12.3倍、3.4倍~8.6倍、3.0倍~4.9倍和2.1倍~2.6倍。本研究表明,两种土壤均存在灌木"肥岛"效应,而土壤质地可能决定了"肥岛"效应的强弱程度。     

Experimental management of Mediterranean temporary pools for conservation of the rare quillwort Isoetes setacea

Mediterranean temporary pools represent unique species-rich habitats with many rare and endangered species. The Roque-Haute Natural Reserve is one of the few sites in France with Isoetes setacea Lam., a very rare Mediterranean quillwort, considered as a keystone species determining a priority habitat for the European Union. Land uses changes have favoured the invasion of the pools by several shrub and tree species (e.g., Ulmus minor, Fraxinus angustifolia subsp. oxycarpa). Clearing shrubs in an experimental area of one pool resulted in the increase of I. setacea as compared to control, combining a higher cover in previously occupied quadrats and more quadrats occupied. Litter accumulation had a negative effect on the population of Isoetes but this effect was detectable only in the cleared area. Light attenuation was shown experimentally to be detrimental to the vegetative and regenerative production of I. setacea. Clearing of the shrubs and removal of the litter led to an increase in the I. setacea populations and therefore appears to be an effective technique for restoring these plant communities invaded by shrubs. Long-term shrub control should be ensured by reintroducing sheep grazing in order to enhance the sustainable conservation of this oligotrophic habitat.     

Avian assemblages along a gradient of urbanization in a highly fragmented landscape

Our goal was to evaluate how avian assemblages varied along a gradient of urbanization in the highly fragmented landscape of coastal southern California. We measured species richness and abundance of birds within continuous blocks of habitat, within urban habitat fragments that varied in landscape and local habitat variables, and within the urban matrix at different distances from the wildland interface. These comparisons allowed us to characterize patterns of avifaunal response to a gradient of urban fragmentation. At the fragment scale, we found that fragment area was a strong, positive predictor of the total number of breeding species detected per fragment; total bird abundance per point count also increased with fragment size. Tree cover was higher in small fragments, as was the abundance of birds that typically occupy wooded habitats. Comparisons between core, fragment, and urban transects revealed differing patterns of response of individual bird species to urbanization. In unfragmented habitat, we recorded a relatively high diversity of urbanization-sensitive birds. In urban transects, these species were rare, and a relatively few species of non-native and anthropophilic birds were common. These urbanization-enhanced birds were also recorded in previous urban gradient studies in northern California and Ohio. Bird communities along the urban gradient reached their highest richness and abundance in fragments. The marked difference in vegetation structure between urban and natural landscapes in this arid shrubland system likely contributed to this pattern; the presence of native shrubs and exotic trees in fragments enabled both shrub and arboreal nesters to co-occur. As is characteristic of biotic homogenization, urban fragmentation in coastal southern California may increase local diversity but decrease overall regional avifaunal diversity.     

Restoration of saline land by halophytes for Indian soils

Usually saline soils were reclamized by chemical or mechanical remediation, since the cost of leaching technique for saline soil reclamation is higher in India. In the present study an attempt has been made to investigate to identify the fast and luxuriantly growing halophytic herbs which are salt accumulators and to assess the feasibility of salt bioaccumulation. From the results it is concluded that among six species studied Suaeda maritima and Sesuvium portulacastrum exhibited greater accumulation of salts in their tissues as well as higher reduction of salts in the soil medium.     

堆肥对苏打草甸碱土植被重建的影响

为建立一个低成本、易推广的苏打草甸碱土植被的快速重建模式,在试验区内随机选取碱斑,直接在碱斑上堆肥.结果表明:灌水 堆肥与常规堆肥盐分调控的效果最好.堆肥浇水处理的出苗率显著高于未浇水处理,秋季浇水与未浇水处理生物量没有差异.碱斑上经过人工植被建植后,草甸碱土上植物群落己演替到羊草 盐碱植物群落阶段,跨越了盐碱植物群落阶段.碱斑上直接进行常规堆肥是苏打草甸碱土植被重建的快速、经济模式.     

Habitat characteristics of adult frosted elfins (Callophrys irus) in sandplain communities of southeastern Massachusetts, USA

Changes to land use and disturbance frequency threaten disturbance-dependent Lepidoptera within sandplain habitats of the northeastern United States. The frosted elfin (Callophrys irus) is a rare and declining monophagous butterfly that is found in xeric open habitats maintained by disturbance. We surveyed potential habitat for adult frosted elfins at four sites containing frosted elfin populations in southeastern Massachusetts, United States. Based on the survey data, we used kernel density estimation to establish separate adult frosted elfin density classes, and then used regression tree analysis to describe the relationship between density and habitat features. Adult frosted elfin density was greatest when the host plant, wild indigo (Baptisia tinctoria), density was >2.6 plants/m² and tree canopy cover was <29%. Frosted elfin density was inversely related to tree cover and declined when the density of wild indigo was <2.6 plants/m² and shrub cover was ?16%. Even small quantities of non-native shrub cover negatively affected elfin densities. This effect was more pronounced when native herbaceous cover was <36%. Our results indicate that management for frosted elfins should aim to increase both wild indigo density and native herbaceous cover and limit native tree and shrub cover in open sandplain habitats. Elimination of non-native shrub cover is also recommended because of the negative effects of even low non-native shrub cover on frosted elfin densities. The maintenance of patches of early successional sandplain habitat with the combination of low tree and shrub cover, high host plant densities, and the absence of non-native shrubs appears essential for frosted elfin persistence, but may also be beneficial for a number of other rare sandplain insects and plant species.     

新疆克里雅绿洲土壤盐分、pH和盐基离子空间异质性分析

以克里雅绿洲盐渍化土壤为研究对象,以野外调查与实地数据为基础,采用空间自相关分析与径向基函数插值法,定量分析了克里雅绿洲土壤的含盐量、pH及盐基离子的空间异质特征。结果表明:绿洲盐渍土表聚性强、呈碱性,土壤含盐量从南至北呈现逐渐增大趋势。土壤含盐量、Na~+、Ca(2+)、K~+、Mg2~+、Cl–、SO_4~(2-)均属于强空间变异,HCO_3~–属于中等强度的空间变异,而pH属极弱变异。土壤盐分含量、pH和盐基离子的Moran’s I指数均通过了显著性检验,研究区土壤含盐量、p H与盐基离子在空间上呈现低聚集性。Pearson相关性分析结果显示,土壤盐分含量与Na~+、K~+、Cl~–和SO_4~(2-)含量具有强正相关性(P0.01),与Ca~(2+)和Mg~(2+)含量中等程度正相关(P0.05);土壤pH与土壤含盐量及盐基离子含量极弱相关。该研究结果可为绿洲水资源合理开发与农业可持续发展提供科学依据,同时可作为盐渍土改良和沙漠化防治等环保工作的决策支撑。     

嘉陵江流域不同类型植被多样性与土壤养分和酶活性的关系

基于2013—2015年对嘉陵江流域中游（四川段）不同植被类型（混交林、草甸、针叶林、阔叶林、灌丛和裸地）多样性和土壤生境的调查分析数据,采用相关分析法和群落排序法研究不同植被类型土壤养分和酶活性分布特征及其与植被多样性之间的关系。结果表明:嘉陵江流域不同植被多样性指数、丰富度指数、优势度指数和植被盖度基本表现为乔木林>灌木林>草甸>裸地,裸地显著低于其他植被类型（p < 0.05）。嘉陵江流域除了裸地和灌丛,其他植被类型土壤pH值均显酸性,pH值与土壤容重变化趋势相一致,基本表现为:裸地>灌木林>乔木林>草甸,裸地显著高于其他植被类型（p < 0.05）。嘉陵江流域土壤养分、有效养分含量和酶活性基本表现为乔木林>灌木林>草甸>裸地,裸地显著低于其他植被类型（p < 0.05）。相关性分析表明:植被多样性与土壤养分和酶活性密切相关,是造成不同植被类型土壤养分差异的重要原因,土壤养分和酶活性在一定程度上决定了植被丰富度和多样性指数,土壤理化性质在一定程度上决定了植被优势度指数,而土壤全碳和全氮在一定程度上决定了植被盖度。冗余分析结果显示丰富度指数、多样性指数、优势度指数和植被盖度之间均呈正相关,与土壤养分和酶活性呈正相关,与pH值和土壤容重呈负相关,这与相关分析的结果相一致。