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1.
Hend Askri Fatma Gharbi Saloua Rejeb Ahmed Mliki Abdelwahed Ghorbel 《Arabian Journal of Geosciences》2017,10(11):246
Salinity problems for vineyards are in concerns, especially in coastal areas where several aquifers are reported to be affected by seawater intrusion and agricultural contamination. Saline irrigation affects growth, yield, and fruit quality of grapevines. Exploring germplasm base through wild ancestors of the target species is a novel adopted strategy to increase crop tolerance to irrigation with saline water. The effects of salt on growth, organic and inorganic solute accumulations, and chlorophyll florescence were studied on 3-month-old plants of six Tunisian wild grapevines with the objective to identify salt tolerance mechanisms and select tolerant genotypes. Potted plants were grown under controlled conditions and irrigated for 14 days with 0, 100, and 150 mM NaCl nutrient solution. Parameters analyzed were related to growth, water relations, mineral nutrition, and chlorophyll fluorescence. Several processes are operating either at the whole plant or at cell level. They appear to be involved in salt tolerance of wild grapevines and are more efficient in tolerant accessions. Salt adversely affects plant growth and plant nutrition. Reductions of shoot growth rate (relative growth rate, day?1) reached 49% of control since 100 mM NaCl. They were assigned to stomatal closure and alteration of potassium nutrition and photochemistry. There were significant differences (P < 0.05) within accessions, Tebaba was the most tolerant and Houamdia the most sensitive, while the others were intermediate. 相似文献
2.
环境矿物、SAP、化学固沙浆材综合治理荒漠初探 总被引：8，自引：3，他引：5
介绍了水玻璃-乙酸乙酯、植物栲胶化学固沙浆材在柱撑蒙脱石、缺铝型沸石的制备方法及性能,并将柱撑蒙脱石、缺铝型沸石、SAP、生根素等以一定的配比和方式复合在一起,制备成具有保水、保肥、保墒等多项功能的“复合富水营养包”,实验室初步证明,在无水、无肥、昼夜温差较大,不采取任何植保措施的情况下,营养包可使树苗在沙土中度过3个月的成活期。根据两种固沙浆材的特性及营养包的功能,提出一种新的治理沙漠的设想;用化学固沙浆材料在较大范围内固定流沙,为树木生长创造一个相对稳定的环境,然后用营养包保活单株树木,当大量树木构成规模林带、林地后,即可实现地下保水、地表固沙、地上成林三维结合的立体综合治荒目标。 相似文献
3.
丛枝菌根影响土壤-植物系统中重金属迁移转化和累积过程的机制及其生态应用 总被引：6，自引：1，他引：6
丛枝菌根真菌(AMF)是在自然和农业生态系统中广泛存在的一类专性共生土壤微生物,能够与80%左右的陆地植物建立共生关系。AMF从宿主植物获取碳水化合物以维系自身生长;作为回报,AMF能够帮助植物从土壤中吸收矿质养分和水分。很多研究表明,AM共生体系对于植物适应各种逆境胁迫(如贫瘠、干旱、环境污染等)具有重要作用。在土壤重金属污染情况下,AMF能够通过多种途径影响植物对重金属的吸收、累积和解毒过程,并对植物产生保护效应。本文围绕AM对土壤-植物系统中重金属迁移、转化和累积过程的影响机制,系统评述了金属元素种类及污染程度、宿主植物和AMF种类,以及土壤理化性质等因素对AM植物吸收累积重金属的影响,并从AMF对土壤-植物系统中重金属行为的直接作用(包括菌丝吸收和固持,以及改变根际重金属形态等),及AMF改善植物矿质营养促进植物生长从而间接增强植物重金属耐性两方面讨论了AM增强植物重金属耐性的机理,系统总结了相关研究领域的前沿动态。最后,对菌根技术在农田和矿区重金属污染土壤生物修复中的应用前景进行了展望。 相似文献
4.
地球上生物因受到太阳光辐射作用而进化出结构精致的光合作用系统。太阳光辐射对地球表面广泛分布的无机矿物的影响与响应机制长期未被重视与理解。我们新发现的地表“矿物膜”转化太阳能系统,具有潜在的产氧固碳作用,体现出自然界中固有的矿物光电效应与非经典光合作用。本文在总结自然界中矿物光电子能量特征,特别是地表“矿物膜”特征及其光电效应性能的基础上,重点探讨铁锰氧化物矿物表现出的光电效应、产氧固碳作用与地质记录。提出矿物享有光电效应特性,地表“矿物膜”富含水钠锰矿、针铁矿、赤铁矿等天然半导体矿物,在日光辐射下具有稳定而灵敏的光电转换性能,产生矿物光电子能量;提出矿物拥有非经典光合作用的性能,自然界无机矿物转化太阳能系统类似生物光合作用吸收转化太阳能的产氧固碳系统,地表“矿物膜”光催化裂解水产氧作用及其转化大气和海洋二氧化碳为碳酸盐矿物作用,孕育出“矿物光合作用”;提出矿物具有促进生物光合作用的功能,生物光合作用中心Mn4CaO5在裂解水产氧过程中产生成分和结构类似水钠锰矿的锰簇化合物结构体,初步认为水钠锰矿可能促使蓝细菌光合作用系统的起源,矿物影响与削弱水分子氢键以改变水的性质,可提高水的分解程度与光合作用效率,为进一步探索矿物促进生物光合作用机理提供科学技术突破的机遇。 相似文献
5.
Under the ever-present solar radiation, photosynthetic organisms on Earth evolved structurally-sophisticated photosynthetic systems. However, little attention has been paid to the inherent impact of sunlight illumination on the inorganic minerals widespread on the Earth surface. We discovered for the first time the solar energy conversion system of the “mineral coatings” on the Earth's surface (aka“mineral membrane”), which exerts potential oxygen-production and carbon-sequestration functions on the Earth surface. Our finding shed a light on the photoelectric effect and non-classical photosynthesis involving natural semiconducting minerals. In this contribution, we studied the semiconducting property and photoelectron energy of typical minerals in the “mineral membrane”, focusing primarily on the photoelectric effect in and oxygen-production/carbon-sequestration function of ferromanganese oxides, as well as relevant geological records. We propose that birnessite, goethite and hematite, the semiconducting minerals commonly found in the “mineral membrane”, can perform sensitive and stable photon-to-electron conversion under solar radiation. The non-classical mineral photosynthetic function we put forth is as follows: Solar energy utilization by inorganic minerals resembles photosynthesis in regarding to oxygen evolution and carbon fixing, and the “mineral membrane” may take part in both photocatalytic water-oxidation reaction and transformation of atmospheric CO2into marine carbonate. In addition, minerals might as well have promoted photosynthesis in photosynthetic organisms. During the water-oxidation reaction, the inorganic cluster Mn4CaO5of photosystem II cycles through redox intermediates that are analogous to birnessite both in structure and component. Thus, it is fair to postulate that birnessites could play a role in the initiation of the photosynthesis in cyanobacteria, as minerals could weaken the hydrogen bond strength and alter water properties, thus facilitating water oxidation and photosynthesis. This observation offers further insights into the molecular mechanism of mineral participation in photosynthesis in photosynthetic organisms. 相似文献
6.
Integrated method of RS and GPR for monitoring the changes in the soil moisture and groundwater environment due to underground coal mining 总被引：3，自引：0，他引：3
Zhengfu Bian Shaogang Lei Hilary I. Inyang Luqun Chang Richen Zhang Chengjun Zhou Xiao He 《Environmental Geology》2009,57(1):131-142
Mining affects the environment in different ways depending on the physical context in which the mining occurs. In mining areas
with an arid environment, mining affects plants’ growth by changing the amount of available water. This paper discusses the
effects of mining on two important determinants of plant growth—soil moisture and groundwater table (GWT)—which were investigated
using an integrated approach involving a field sampling investigation with remote sensing (RS) and ground-penetrating radar
(GPR). To calculate and map the distribution of soil moisture for a target area, we initially analyzed four models for regression
analysis between soil moisture and apparent thermal inertia and finally selected a linear model for modeling the soil moisture
at a depth 10 cm; the relative error of the modeled soil moisture was about 6.3% and correlation coefficient 0.7794. A comparison
of mined and unmined areas based on the results of limited field sampling tests or RS monitoring of Landsat 5-thermatic mapping
(TM) data indicated that soil moisture did not undergo remarkable changes following mining. This result indicates that mining
does not have an effect on soil moisture in the Shendong coal mining area. The coverage of vegetation in 2005 was compared
with that in 1995 by means of the normalized difference vegetation index (NDVI) deduced from TM data, and the results showed
that the coverage of vegetation in Shendong coal mining area has improved greatly since 1995 because of policy input RMB￥0.4
per ton coal production by Shendong Coal Mining Company. The factor most affected by coal mining was GWT, which dropped from
a depth of 35.41 m before mining to a depth of 43.38 m after mining at the Bulianta Coal Mine based on water well measurements.
Ground-penetrating radar at frequencies of 25 and 50 MHz revealed that the deepest GWT was at about 43.4 m. There was a weak
water linkage between the unsaturated zone and groundwater, and the decline of water table primarily resulted from the well
pumping for mining safety rather than the movement of cracking strata. This result is in agreement with the measurements of
the water wells. The roots of nine typical plants in the study area were investigated. Populus was found to have the deepest
root system with a depth of about 26 m. Based on an assessment of plant growth demands and the effect of mining on environmental
factors, we concluded that mining will have less of an effect on plant growth at those sites where the primary GWT depth before
mining was deep enough to be unavailable to plants. If the primary GWT was available for plant growth before mining, especially
to those plants with deeper roots, mining will have a significant effect on the growth of plants and the mechanism of this
effect will include the loss of water to roots and damage to the root system. 相似文献
7.
石漠化地区的生态危机及菌根桑生物修复潜力研究进展 总被引：3，自引：1，他引：2
在简要总结出石漠化地区的生态特征、生态威胁及生态恢复存在的主要障碍的基础上,比较系统地分析了桑树在石漠化生境中已表现出的生态适应能力和生态修复潜力。桑树作为喀斯环境的速生造林树种,根系发达,耐干旱耐贫瘠能力极强,对增加植被覆盖率、促进生态环境改善、实现石漠化地区脆弱生态系统的恢复与平衡产生重要作用。尤其是由于丛枝菌根具有对矿质营养和水分吸收能力强的特殊生理生态功能,刚好与石漠化地区贫瘠和干旱这一主要生态障碍相耦合,接种丛枝菌根真菌后能进一步扩大桑树对矿质营养和水分的吸收与运输,减轻贫瘠干旱胁迫,加快土壤微生物群落构建,提高土壤生物活力,促进植被群落正向演替。种植菌根桑可望成为喀斯特石漠化生态修复一种新途径。 相似文献
8.
《International Geology Review》2012,54(7):609-618
The use of plants as indicators in prospecting for minerals is discussed on a broad scale from the standpoints both of available literature and field experiments. The method of isoline mapping of mineral deposits by means of metal content in ashes of plant parts is detailed,. The author cautions against too broad use of any single species as a “direct” indicator or too heavy reliance on ash content, as some species tend to concentrate certain minerals, regardless of soil composition. Instead, a combination of species as indicators and a combination of factors, such as appearance of leaves, luxuriance of the plant, and color and time of blooms is recommended. The tendency of some minerals to nullify the effect of others–iron counteracting the effect of copper, for instance — is noted, as well as different effects on plants of different salts of the same mineral. In spite of these qualifications and the early, stage of development of this technique, the method has particular merit in areas where the strata overlying the metal-bearing deposits is relatively thick. Analyzing the ash content of leaves of deep-rooted trees is particularly helpful in detecting the presence of an ore mineral in such a situation. — A. Eustus 相似文献
9.
T. M. Mwamba S. Ali B. Ali J. L. Lwalaba H. Liu M. A. Farooq J. Shou W. Zhou 《International Journal of Environmental Science and Technology》2016,13(9):2163-2174
Heavy metals’ frequent occurrence and toxicity caused considerable concerns in assessing the interactive effects of metals on exposed plants. Therefore, a hydroponic study was conducted to assess the growth response and physio-chemical changes in Brassica napus plants under single and combined stress of two environmentally alarming metals (Cd and Cu). Results showed that 15-day metal exposure to different metal concentrations (0, 50, 200 µM) significantly enhanced Cd accumulation, while lesser extent of Cu was observed in plant tissues. Nonetheless, Cu caused more pronounced oxidative damages and plant growth retardation. Both metals showed similar trend of changes in mineral composition, although Cu proved more damaging effect on K and Mn contents, and Cd on Zn contents. In combined treatments, Cd stimulated Cu uptake, notably at low concentration, while its own uptake was restricted by the presence of Cu. At either level of concentration, combined stress of these metals exacerbated plant growth inhibition and caused further oxidative damages compared to their individual stress. However, metals synergistic effects occurred only in conditions where Cu uptake was enhanced by Cd. A greater synergistic effect was observed in sensitive cultivar Zheda 622 as compared to the tolerant cultivar ZS 758. As to mineral composition, no metals synergistic effects were noted. This study highlighted the ecotoxicological significance of Cd-led Cu uptake in B. napus, which was assumed to drive metals’ synergistic toxicity, and showed that the relationship between Cd-led Cu uptake and plant growth responses could vary with respect to cultivar. 相似文献
10.
中国矿业可持续发展与煤矿开采环境问题—21世纪初矿山岩石力学面临的新机遇和挑战 总被引：3，自引：0，他引：3
列述了中国在陆地传统矿产资源、海域矿产资源、天然气、煤层气、地热等能源资源方面的相当大的开发潜力。提出了中国矿业可持续发展必须解决的若干岩石力学难题。指出了煤矿开采引发的环境问题:如采煤对土地资源的损害、对村庄的损害、对水资源的影响,以及煤炭开发和利用对大气环境生态平衡的影响。并提出了对矿区环境控制的岩石力学对策,即推行减沉开采技术;矿井水资源的保护和再利用;清洁开采技术。 相似文献
11.
非饱和带属于地球关键带,与人类生存环境及安全健康关系密切,而CO2对生态环境及全球气候变化的影响至关重要。为了探索高浓度CO2入侵非饱和带对生态环境可能带来的风险,基于长安大学水与环境原位试验场CO2试验平台,向种植有5种典型植物（黑麦草、小麦、玉米、豌豆和苋菜）的土壤中长期注入浓度为5%、10%和15%的CO2气体,评估CO2入侵对植物和土壤的潜在影响。对表生植物及土壤样品（深度为20～30 cm）的理化性质分析表明:高浓度CO2明显抑制了植物的生长,会导致植株高度、叶片数和果实重量下降;土壤矿相和理化性质也有微小变化,表现为土壤pH值的变化以及氮、有效钾、有效磷等的减少。通过分析植物的光合作用、渗透调节作用以及抗氧化系统的变化,不同的植物对CO2胁迫表现出不同且复杂的响应,总体上C3单子叶植物黑麦草和C4单子叶植物玉米显示出比其他植物更高的敏感性,表明它们有潜力作为评估CO2生态影响的指示植物。 相似文献
12.
柴达木盆地格尔木河流域生态需水量初步估算探讨 总被引：9，自引：1，他引：8
格尔木河流域是柴达木盆地工农业较发达地区之一。近年来,随着流域水资源开发利用程度不断加大,用水结构欠合理,生态环境趋于恶化。本文从流域主要植物生长状态分析了地下水位埋深对植物生长的影响,确定了不同植物对地下水位埋深、地层岩性和不同盖度下的植物蒸发蒸腾强度。从研究流域生态需水量出发,分别对河道内、河道外天然植被和东达布逊湖生态需水量进行了初步估算,分析了水资源开发利用对生态环境的影响,从而为今后研究流域水资源开发利用和生态环境保护提供理论参考。 相似文献
13.
Effects of Salt Stress on Plant and the Mechanism of Arbuscular Mycorrhizal Fungi Enhancing Salt Tolerance of Plants 总被引：1，自引：0，他引：1
Soil salinization is one of the global land degradation problems due to the impacts of climatic variations and human activities. As a beneficial soil microorganism, Arbuscular Mycorrhizal Fungi (AMF) are abundant in saline-alkaline land and form a mutual symbiosis with plants, which can improve salt tolerance of plant and reduce salt stress from the soil. Based on the mechanism of salt stress on the plant, the effects of AMF on plant physiological characteristics were introduced. Three main aspects of the AMF effects were summarized as follows: reconstructing the ion balance in plants to alleviate the toxic effects of specific ions; expanding the absorption range of plant roots and improving the osmotic regulation ability to alleviate the water deficit in plant; maintaining the integrity of cell membrane system and photosynthetic system to resist the damage caused by oxidative stress. Also, the future research direction in this field was evaluated, then a reference for the reconstruction of the saline-alkaline environment was provided. 相似文献
14.
The objective of this study was to experimentally evaluate the effects of simulated herbivory on the ability of a freshwater marsh plant to recover from temporary saltwater intrusion such as can be caused by tropical storms. Sods containingSagittaria lancifolia, a dominant plant in interior coastal marshes, were manipulated in the field so as to subject plants to a pulse of 15‰ salt water for a duration of 1 wk. In addition to the exposure to salt water, some plants were also subjected to both short-term and long-term flooding treatments of 20 cm, and to simulated herbivory (clipping). Following exposure to salt water, plants were allowed to recover over the winter and were harvested the next June. Neither simulated herbivory, nor salinity, nor flooding caused any long-term effect either singly or in pairwise combinations. However, when plants were subjected to herbivory, salt water, and flooding simultaneously, reduced growth and plant death occurred. These results suggest that high levels of grazing by herbivores may increase the susceptibility of coastal marsh plants to damage from saltwater intrusion. *** DIRECT SUPPORT *** A01BY073 00002 相似文献
15.
ABSTRACT: The colonization of the terrestrial environment by land plants transformed the planetary surface and its biota, and shifted the balance of Earth's biomass from the subsurface towards the surface. However there was a long delay between the formation of palaeosols (soils) on the land surface and the key stage of plant colonization. The record of palaeosols, and their colonization by fungi and lichens extends well back into the Precambrian. While these early soils provided a potential substrate, they were generally leached of nutrients as part of the weathering process. In contrast, volcanic ash falls provide a geochemically favourable substrate that is both nutrient-rich and has high water retention, making them good hosts to land plants. An anomalously extensive system of volcanic arcs generated unprecedented volumes of lava and volcanic ash (tuff) during the Ordovician. The earliest, mid-Ordovician, records of plant spores coincide with these widespread volcanic deposits, suggesting the possibility of a genetic relationship. The ash constituted a global environment of nutrient-laden, water-saturated soil that could be exploited to maximum advantage by the evolving anchoring systems of land plants. The rapid and pervasive inoculation of modern volcanic ash by plant spores, and symbiotic nitrogen-fixing fungi, suggests that the Ordovician ash must have received a substantial load of the earliest spores and their chemistry favoured plant development. In particular, high phosphorus levels in ash were favourable to plant growth. This may have allowed photosynthesizers to diversify and enlarge, and transform the surface of the planet. 相似文献
16.
云南宝石级矿种有50余种，其中较为知名且有开发价值的有：滇南的祖母绿宝石、高黎贡山碧玺、哀牢山红宝石、云南锡石、绿柱石、石榴子石、滇西异极矿等。本文作概略介绍。 相似文献
17.
Ecosystem model of an estuarine submersed plant community: Calibration and simulation of eutrophication responses 总被引：1，自引：0，他引：1
As water quality in the Chesapeake Bay has declined over recent decades, formely healthy submersed plant communities have disappeared from littoral areas of the mesohaline estuary. A dynamic simulation model of shallow regions of bay tributaries (<1 m) was developed to investigate growth responses of submersed vascular plants to eutrophication and habitat degradation. Our objectives were to elucidate mechanisms responsible for the decline and to evaluate conditions required for plant restoration and survival. State varibles in the model are plant leaves, roots, phytoplankton, epiphytes, and detrital material. The model calculates biomass pools and biogeochemical rate processes over annual cycles with a time step of 6 h. Simulations were performed to investigate the influence of phytoplankton and epiphytes on the underwater light environment, how the balance of limiting resources (light and nutrients) controls growth and productivity of submersed plants, and conditions necessary, for the restoration of submersed vegetation. Model output for submersed plants was calibrated to baseline data from the mid 1970s (r2=0.86); simulations reproduced declines in plant biomass with increasing nutrient enrichment. Model experiments showed, that by increasing nutrient inputs 40% above levels observed in the 1960s, submersed plants disappeared within 1–2 yr due to enhanced growth of phytoplankton and epiphytes, which reduced light below required levels. Epiphytes were more important than were phytoplankton in attenuating light. The relationship between nutrient enrichment and plant loss rate was complex, as epiphyte density on leaf surfaces was not linearly related to nutrient levels. Relatively small nutrient increases could have a large effect on submersed plants because epiphyte density on leaves increased exponentially as leaf surface area decreased. Exchanges of organic carbon and nutrients between leaf and root compartments were seasonally variable and were critical for survival of submersed plants. The amount of root-rhizome material available for regrowth could control the outcome of nutrient reduction strategies. Consequently, model predictions of plant restoration success were highly dependent on initial conditions. The model is being used successfully as a research tool to interpret ecological relationships in the ongoing re-evaluation of management alternatives for submersed plant restoration. 相似文献
18.
风沙流对植物生长影响的研究 总被引：19，自引：1，他引：19
在中国乃至全球，风沙活动都十分频繁，它直接影响着风沙地区植物资源的可持续利用与发展，因此，研究风沙流对植物生长的影响十分必要。以往，相关的研究主要是围绕沙漠逆境的综合条件（如降水、温度、湿度、土壤水分、养分等综合因子）进行的，研究内容涉及植物的生理、生化、物质代谢以及生态适应性等。但国内外就风沙流单因子对植物生理生化影响的研究还没有深入展开，为此，作者利用野外风洞条件，就不同风况下的风沙胁迫对某些植物生长特征的影响进行了实验研究；结果表明：风沙流胁迫可使植物的净光合速率（Pn）、气孔导度（Cs）、叶温（Tl）、叶片水势（Wp）降低，使蒸腾速率（Tr）升高；且风速越大，吹风间隔越短，这些参数变幅越大；风沙流比净风的影响更大。风沙流能降低试验植物的水分利用率，进而增加植物的干燥作用；同时可使脯氨酸含量增加。由于风沙流运动和植物的复杂多样性，因此这个研究领域还有许多问题需要探索。 相似文献
19.
深圳市东湖矿泉水形成机理探讨 总被引：5，自引：0，他引：5
深圳市东湖矿泉水是自然界十分稀少的锶—锌—偏硅酸碳酸复合型矿泉水，通过对矿泉水赋存地的地质与水文地质条件的分析，并结合其水文地球化学特征，认为东湖矿泉水形成的主要控制性因素是构造作用和变质作用；在特定的水文地质条件下，深部碳酸盐类岩石受热硅化变质而产生大量CO2气体，使得各种化学元素在含有大量CO2的地下水的溶滤作用下不断迁移和富集而形成该区地下水中良好的元素组合。在其特征成分中，偏硅酸来自裂隙渗透水的溶滤和岩浆期后热液水的作用，微量元素锶主要来源于钾长石、钙长石，锌则主要来自岩浆活动以及岩脉中的黑云母、角闪石、辉石等铁镁硅酸盐矿物；并认为目前矿泉水含水层仍处于良好的地质环境保护下。 相似文献
20.
Saifullah Nadeem Sarwar Sadia Bibi Mahtab Ahmad Yong Sik Ok 《Environmental Earth Sciences》2014,71(4):1663-1672
Cadmium (Cd) is a highly toxic heavy metal and its presence in soil is of great concern due to the danger of its entry into the food chain. Among many others, proper plant nutrition is an economic and practicable strategy for minimizing the damage to plants from Cd and to decrease Cd accumulation in edible plant parts. The study was carried out to compare the effectiveness of soil and foliar applications of zinc (Zn) to minimize Cd accumulation in wheat grains. The results revealed that the exposure of plants to Cd decreased plant growth and increased Cd concentration in the shoots and grains of wheat, when compared with unexposed plants. Foliar application of 0.3 % zinc sulfate solution effectively decreased Cd concentration in wheat grains. Foliar application of Zn at a suitable concentration can effectively ameliorate the adverse effects of Cd exposure and decrease the grain Cd concentration of wheat grown in Cd-contaminated soil. 相似文献