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1.
Volos city and its port are situated in the northern part of Pagassitikos Gulf, a shallow, semi-enclosed marine area in central Greece. A wastewater treatment plant (WWTP) and pipeline operate in the same area. Muddy sediments with low carbonate contents cover most of the seabed, except for the Volos embayment and the western part of the gulf where sandy carbonates prevail. Bulk organic carbon contents and the organic carbon contents of the clay fractions are high in the vicinity of Volos embayment. High element (Pb, Cu, and Zn) contents and Igeo (geoaccumulation index) values were found for the clay fractions in the northern part of Pagassitikos Gulf. This enrichment is attributed to the discharge of raw domestic and industrial effluents of Volos city and port before the WWTP was installed. The dispersal of pollutants is essentially controlled by diffusion from point sources (city, port and WWTP) and is limited to Volos Bay. Relatively high Mn levels are ascribed to diagenetic formation of manganese carbonates (authigenic phase), whereas Cr and Ni are elevated due to weathering of ultrabasic formations on land.  相似文献   

2.
The concentrations of Ni, Mn, Cr, Cu, Co, Zn, Fe, Pb and organic carbon have been determined in sediments of the Pagassitikos Gulf. They vary with the ‘sand equivalent’ content, s′, characteristic of the grain size, and are related to it by the equation,
c = c1·k·s′d
in which the constants c1, k and d depend on the element. Consequently, since the metal concentrations in a sample are much less representative of the area from which it has been taken than its ‘sand equivalent’ content, a contour map of the latter constitutes a reliable guide to the general pattern of the elements. Superimposed on it, we detect isolated patches of moderate pollution close to the harbour of Volos and a few, slight, natural anomalies, such as increased Mn and Ni, the former in the east and the latter in the south of the Gulf.  相似文献   

3.
Previous studies of modern peritidal sedimentary environments of the Red Sea, such as hypersaline lagoons and sea-marginal flats, have concentrated on its northern part, particularly in the Gulf of Aqaba. However, little is known about lagoon sediments in other localities along the Red Sea coastal stretches. This paper deals with the chemical characteristics of the sediments of a hypersaline (Ras Hatiba) lagoon, north of Jeddah, Saudi Arabia. The chemistry of hypersaline lagoon sediments is considerably changed following the modifications to the water chemistry by evaporation and precipitation.Ras Hatiba lagoon is a hypersaline elongated water body connected to the Red Sea by a narrow and shallow opening. The total area of the lagoon is c. 30 km2.Coarse bioclastic sands are dominant in the lagoon and mostly surround lithified calcareous grounds. However, fine silt and clay sediments are present in separate patches. The sediments are rich in carbonates (average 78·5%) and organic carbon (average 7·3%), although they are negatively correlated. Calcium (average 25·1%) and magnesium (average 10·8‰) show a similar distribution pattern in the lagoon sediments. Strontium (average 5·2‰) is positively correlated with calcium. Sodium and potassium are relatively highly concentrated in the sediments (average 118 ppm and 173 ppm, respectively). Magnesium and strontium are of prime importance in the process of mineralization and diagenesis.The sabkha formation surrounding the lagoon is of low carbonate and organic carbon content, compared with the lagoon sediments, whilst it is characterized by high magnesium, sodium and potassium concentrations.Ras Hatiba lagoon sediments and sabkha resemble those of the northern Red Sea in the Gulfs of Aqaba and Suez and the Arabian Gulf in their major sedimentological and chemical characteristics.  相似文献   

4.
连云港西大堤工程建设影响作用评价   总被引：4，自引：0，他引：4  
徐军 《海洋通报》2005,24(5):67-73
西大堤的建成使连云港由原来的海峡通道型港口变为半封闭的人工海湾型港口,风浪条件改善,可利用的港口岸线大大加长,为连云港亿吨大港的建设提供了契机,也改善了连云港与东西连岛的交通条件,促进了旅游业的发展.另一方面,也改变了海湾内水动力与沉积环境.大堤建成后,湾内潮波由前进波转变为驻波,水体交换能力减弱,湾内水质污染加重,尤其是湾顶水域污染最重;同时加剧了湾内泥沙的淤积,在西大堤内侧形成新的潮滩,位于湾顶的老海滨浴场被淤废.由于西大堤封堵了连云海峡西口门,使得近岸泥沙的运移路径改变,北部的泥沙流自海州湾东去沿大堤折向东西连岛方向,在大堤的外侧和东西连岛外缘形成新的落淤场所,大沙湾和苏马湾海滨浴场受到影响.沉积作用的加剧已影响到港口及周边海岸与水利设施的正常运作,因而应加强对港区及周边海洋环境的监测与研究,缓建西大堤内侧北港区码头,并对西大堤西端进行透空式改造,以从根本上解决港区泥沙淤积问题.  相似文献   

5.
环雷州半岛近海表层沉积物有机碳分布及其控制因素分析   总被引：1，自引：0，他引：1  
对环雷州半岛近海43个海底表层沉积物的总有机碳(TOC)、总氮(TN)、沉积介质条件(包括沉积物粒度)进行了分析,探讨了沉积物TOC、TN的区域分布特征以及影响有机碳分布的主要因素。结果表明,环雷州半岛近海海域海底表层沉积物有机碳含量在0~0.79%之间,平均值为0.26%。与中国其它近海海域相比,环雷州半岛大部分近海区域海底表层沉积物有机碳含量明显偏低,为有机质贫乏区,仅雷州半岛西南部流沙湾近海海域为TOC相对高值区。总氮含量也不高,在0.011%到0.100%之间,TOC与TN存在较强的正相关性,且平面上TOC与TN分布高度重合,显示氮元素主要以有机化合物形式存在。TOC/TN比值在5.1~14.3之间,表明沉积有机质具有陆源输入和海洋自生来源的混合特征,但以雷州半岛西侧北部及东侧中部海域受陆源有机质输入影响更大。大多数站位海底沉积物粒度构成以粉砂为主、粘土次之,少数站位以砂质沉积为主。沉积物有机碳含量与粘土及粉砂含量呈弱正相关性,与沉积物pH值、Eh值及砂含量呈弱负相关性,这表明海底沉积物有机质丰度受有机质来源输入、海底氧化还原状态和沉积水动力条件(沉积物粒度)等因素综合控制。  相似文献   

6.
C.M. Davies 《Marine Geology》1974,16(2):M31-M38
Two separate current systems have been identified in Swansea Bay — a rotatory current system, located in the northern part of the embayment, and a rectilinear current system, offshore. The amount of fine-grained sediment suspended in the rotatory currents varies with both direction during a tide cycle and tidal range. Measurements of suspended sediment indicate that the suspended load is higher on neap tides than spring tides. This is due to a change in axial orientation of the rectilinear system, which directs ebb-tide currents towards the northern part of the embayment on neap tides, but “deflects” ebb-tide currents from the northern area on spring tides.  相似文献   

7.
According to bioassay studies and high dissolved nutrient N/P ratios in the seawater column, phosphorus (P) is thought to control marine productivity in the northern Adriatic Sea. P in near-shore marine sediments of the Gulf of Trieste, the northernmost part of the Adriatic Sea, was investigated using pore water P distributions, and benthic P flux studies under oxic and anoxic conditions. The data show that P regeneration is up to three-fold more extensive in sediments overlain by oxygen-depleted waters and proceeds in parallel with Fe and Mn enhanced benthic fluxes. It appears from the incubation experiments that degradation of sedimentary organic matter is the main contribution to the flux of P at the sediment–water interface, while the release of phosphate adsorbed on the iron oxide surface is of minor importance.It appears that about 50% of P in the Gulf of Trieste is retained within in the sediments, probably bonded to clay minerals and carbonate grains or precipitated as fluoroapatite. In these sediments total P (Ptot) is preserved preferentially over organic C (Corg). P regenerated from surficial sediments contributes about 1/3 of the P that is assimilated by benthic microalgae. The phytoplankton P requirement should be entirely supplied from fresh-water sources. These results suggest that oxygen depletion in coastal areas caused by eutrophication enhances P regeneration from sediments, providing the additional P necessary for increased biological productivity. The development of anoxic bottom waters in coastal areas enhances the recycling of P, exacerbating the nutrient requirement in the area. A geochemical record of P burial in a longer sedimentary sequence revealed an increasing trend of Ptot and organic P (Porg) contents occurring approximately 50 years BP (after 1950), probably due to increasing use of inorganic fertilizers and detergents in the area.  相似文献   

8.
从分级的角度认识大河三角洲前缘河口沉积有机碳的来源、分布和保存对深刻理解全球碳循环具有重要意义。于2012年6月采集了长江口和浙闽沿岸共6个站位的表层沉积物样品,采用水淘选的方法按照颗粒物水动力直径大小对其进行分级分离,分析了这些分级样品的有机碳含量、稳定同位素、比表面积以及木质素等参数,并且结合蒙特卡洛模拟的三端元混合模型,讨论了此区域不同粒级沉积有机碳的来源、分布和保存特点。结果表明,长江口表层沉积物的有机碳在小粒级中含量较高,如8~16μm粒级有机碳含量的均值为1.30%,而32~63μm粒级的均值为0.90%,但是大粒级有机碳对沉积物有机碳的贡献最高(81.3%),这是因为大粒级的质量贡献占绝对优势(72.0%)。三端元混合模型的计算结果表明,长江口表层沉积物中沉积有机碳的贡献以海洋来源为主(平均为73%),土壤和维管植物也有一定贡献(平均值分别为21%和6%)。在小粒级(8~16μm)中,土壤对于沉积有机碳的贡献显著高于其他粒级,这是由于土壤有机质比较容易富集在细颗粒上。木质素的参数,如C/V(0.04~0.32)和S/V(0.33~1.23),显示长江口表层沉积物主要来源于草本和木本被子植物的混合,随着粒级的增大,草本被子植物的来源逐渐增多。浙闽沿岸分级沉积物的OC/SSA0.4mg/m2,而长江口的站位中OC/SSA0.4mg/m2,表明长江口沉积有机碳的保存效率比浙闽沿岸的高。木质素降解参数,如(Ad/Al)v、3,5-Bd/V和P/(S+V)随着粒级的增大逐渐降低,表明小粒级降解程度较高,而大粒级中降解程度较低。  相似文献   

9.
The processes involved in the interaction between organic fluids and carbonates, and the resulting effect on reservoir quality during the evolution and maturation of organic matter remain unclear despite the fact that these processes influence the carbon and oxygen isotopic compositions of carbonates. Here, we provide new insights into these processes using data obtained from a detailed analysis of a mixed dolomitic–clastic and organic-rich sedimentary sequence within the middle Permian Lucaogou Formation in the Junggar Basin of NW China. The techniques used during this study include drillcore observations, thin section petrography, scanning electron microscopy (SEM) and electron probe microanalysis, and carbon and oxygen isotope analyses. Oil grades and total organic carbon (TOC) contents represent the amount of oil charging and the abundance of organic fluids within a reservoir, respectively, and both negatively correlate with the whole-rock δ13C and δ18O of the carbonates in the study area, indicating that organic fluids have affected the reservoir rocks. Secondary carbonates, including sparry calcite and dolomite overgrowths and cements, are common within the Lucaogou Formation. Well-developed sparry calcite is present within dark mudstone whereas the other two forms of secondary carbonates are present within the dolomite-rich reservoir rocks in this formation. Comparing thin section petrology with δ13C compositions suggests that the carbon isotopic composition of matrix carbonates varies little over small distances within a given horizon but varies significantly with stratigraphic height as a result of the development of secondary carbonates. The net change in whole-rock δ13C as a result of these secondary carbonates ranges from 1.8‰ to 4.6‰, with the secondary carbonates having calculated δ13C compositions from −18.6‰ to −8.5‰ that are indicative of an organic origin. The positive correlation between the concentration of Fe within matrix and secondary carbonates within one of the samples suggests that the diagenetic system within the Lucaogou Formation was relatively closed. The correlation between δ13C and δ18O in carbonates is commonly thought to be strengthened by the influence of meteoric water as well as organic fluids. However, good initial correlation between δ13C and δ18O of whole rock carbonates within the Lucaogou Formation (resulted from the evaporitic sedimentary environment) was reduced by organic fluids to some extent. Consequently, the δ13C–δ18O covariations within these sediments are not always reliable indicators of diagenetic alteration by organic fluids or meteoric water.The characteristics and δ13C compositions of the sparry calcite within the formation is indicative of a genetic relationship with organic acids as a result of the addition of organic CO2 to the reservoir. Further analysis suggests that both carbonate and feldspar were dissolved by interaction with organic CO2. However, dissolved carbonate reprecipitated as secondary carbonates, meaning that the interaction between organic fluids and dolomites did not directly improve reservoir quality, although this process did enhance the dissolution of feldspar and increase porosity. This indicates that the δ13C and δ18O of secondary carbonates and their influence on whole-rock carbonate isotopic values can be used to geochemically identify the effect of organic fluids on closed carbonate-rich reservoir systems.  相似文献   

10.
Sediment samples from two 40-m cores drilled in two different sedimentological environments in the Gulf of Trieste (Northern Adriatic), i.e. in the salt marsh of Sečovlje and in the inner part of the Bay of Koper, were taken for geochemical analysis of organic matter. The organic geochemical analysis comprised the analyses of organic carbon, nitrogen and phosphorus contents and the analyses of amino acid and hexosamine nitrogen and total carbohydrate contents in the samples. Parallel analyses of carbon and oxygen isotopic composition in calcite, and of the granulometric and mineralogical composition of the samples were performed.Depth variations of the distribution pattern of organic carbon, nitrogen, phosphorus, amino acids, hexosamines and carbohydrates in the cores indicate temporal variability of organic matter deposition and transformations in a changing fluvial-brackish-marine environment in the past. The results also provide information on paleoecological changes in the Gulf during Quaternary sedimentation processes. It appears that the marine environmental conditions in the past were not markedly different from those of the present day.  相似文献   

11.
This study is an attempt to solve the problem of oil generation, migration and accumulation of oil in El-Ayun Field, Gulf of Suez. The organic carbon, hydrogen and organic matter contents in addition to the composition of kerogen are determined. The degree of transformation of organic matter to hydrocarbon and the level of thermal maturity of these sediments to yield hydrocarbons are deduced. The geothermal gradient mnd level of organic metamorphism (LOM) are determined by using the bottom hole temperature. The vitrinite reflectance values are used in this respect. The determined trace element contents for both crude oils and sediments clarifies the process of oil migration from possible source rocks to oil reservoirs.Recommendations, concerning exploratory testing of favourable sites for oil accumulation, laterally and vertically, are postulated on the basis of the achieved results.  相似文献   

12.
Abstract. The abundance and taxonomic diversity of phytoplankton have been studied in relation to certain environmental factors in the South Euboikos Gulf, a restricted tidal embayment on the eastern coast of Greece. The northern part of the gulf with higher tidal current, influenced by sewage and industrial effluents, showed high concentrations of nutrients, a greater total density of phytoplankton, relatively high chlorophyll a content, and a lower taxonomic diversity when compared with the southern part. The phytoplankton cycle was largely due to changes in diatom concentration. A slight variation in the occurrence of species and dominance could be observed along the salinity gradients.  相似文献   

13.
渤海湾表层沉积物中有机碳的分布与物源贡献估算   总被引：9，自引：0，他引：9  
依据渤海湾及其邻近海域163个表层沉积物样品的总有机碳(TOC)和总氮(TN)的分析数据,探讨了渤海表层沉积物TOC的空间分布与物源贡献.结果显示,渤海湾TOC呈现南高北低的空间分布特征,TOC与粒度有一定的相关性且TOC高含量区与泥质区相吻合,表明TOC分布在一定程度上受控于沉积动力环境.TOC和TN之间显著相关,在...  相似文献   

14.
Seepage of hydrocarbon-rich fluids out of the marine sedimentary column is characterized by temporal changes of flow intensity and resultant spatially variable redox conditions. Authigenic carbonates at marine hydrocarbon seeps provide excellent geological and geochemical archives that serve to explore seepage dynamics over time. In this study, we investigated the potential of Mössbuaer spectroscopy and Fe contents of seep-related authigenic carbonates from the Congo Fan, the Gulf of Mexico, and the Black Sea for reconstructing past redox conditions and fluid seepage activity at cold seeps. The Fe speciation observed by Mössbauer spectroscopy and Fe contents suggest that (1) the Congo Fan carbonates precipitated in a sulfidic environment, (2) the formation conditions of seep carbonates were variable at the Gulf of Mexico seep site, ranging from oxic to suboxic and anoxic and even spanning into the methanogenic zone, and (3) the stratified water column of the Black Sea or suboxic condition resulted in low Fe contents of Black Sea carbonates. The study reveals that Fe speciation can provide constraints on the wide range of redox conditions that imprinted seep carbonates during the life span of seepage. Similarly, Mössbauer spectroscopy – particularly when used in combination with the analysis of redox-sensitive elements – is a promising tool to trace variable redox conditions in marine paleoenvironments other than seeps.  相似文献   

15.
Sediment samples were selected from 28 sites across the deep (212–3527 m) northern Gulf of Mexico (GOM) as part of the Deep Gulf of Mexico Benthos (DGoMB) program, and analyzed for geochemical parameters related to organic carbon (OC) distribution and characteristics. The results of this study indicate that the OC content of sediments in the deep northern GOM is controlled by several factors; including water depth, overlying water productivity, sediment carbonate content, sediment oxygen exposure time, OC sources, and regional influences. The best correlation between sediment OC content, on a CaCO3-free basis, and other parameters examined was an inverse correlation of OC with water depth. The OC/SA ratio had a wide range of values and, along with variable sources of sedimentary OC, indicated that the organism-available concentration of metabolizable organic matter may not be simply related to sedimentary OC content. This was perhaps reflected in the observation that benthic macrofaunal and meiofaunal biomass abundances were well correlated with sedimentary OC, but the abundance of bacteria in sediments was not.  相似文献   

16.
F.I Khalaf  M Ala 《Marine Geology》1980,38(4):331-348
The coast of the State of Kuwait is characterized by a relatively wide intertidal flat area. At the north, where it is close to Shatt-al-Arab estuary, the intertidal sediments are mainly fluviomarine, while open marine sediments dominate the southern intertidal flat area. Samples were examined from the intertidal zone of deposition from the fluviomarine and open marine environments.The sediments consist mainly of carbonate minerals (low-Mg calcite, high-Mg calcite, aragonite and dolomite), quartz, feldspars, clay minerals and heavy minerals. The mineralogy of the clay fractions of the sediments is dominated by illite, mixed-layer illite—montmorillonite, montmorillonite, chlorite, kaolinite and palygorskite with only minor amounts of quartz. Heavy minerals are concentrated in the very fine sand fraction and are dominated by opaque minerals, amphiboles, pyroxenes, epidotes, garnet, kyanite and sillimanite. Zircon, tourmaline, andalusite, staurolite and rutile are present in subordinate amounts.Three main sources are suggested for the intertidal sediments of Kuwait: (a) Shatt-al-Arab fluviatile deposits, (b) aeolian dust fallout, and (c) direct chemical and biogenic precipitation from the Gulf water.  相似文献   

17.
Subsurface Upper Triassic sediments of northern Jordan represent part of a regressive evaporitic-clastic succession that marks the shrinkage phase of the Late Triassic basin in the northern parts of the Arabian Plate. Sabkhas developed along the basin margin, whereas, oolitic shoals formed on the deeper parts of the carbonate platform. The basin reached a drewdown stage in the Risha, Palmyra and parts of northern Iraq, where halite was precipitated. Local shales, marls and argillaceous limestones are the major source rocks. The total organic content values of the shales and carbonates range between 0.5–1.9%. The main reservoir rocks are the oolitic limestones with porosities of 8–20% and permeabilities that range between 0.01–80 md. Regional swells and troughs that were cut by normal and strike-slip faulting are the main structural styles in the area. Favourable conditions for hydrocarbon generation and accumulation may be found under the Hauran Basalts in NE Jordan.  相似文献   

18.
The 25 sediment samples collected from the Gulf of Thailand and the South China Sea were analyzed for clay mineral investigation. Results showed the presence of 35% montmorillonite, 13% chlorite, 30% illite, and 22% kaolinite in sediments of the Gulf and also 16% montmorillonite, 21% chlorite, 41% illite, and 22% kaolinite in sediments of the South China Sea. The relatively high concentration of montmorillonite in sediments of the Gulf as compared with that in sediments of the South China Sea may suggest that montmorillonite in these area has been largely derived from soil formation of the bordering land areas of the Gulf, particularly from the northern part of Malay Peninsula. On the contrary, the content of illite in sediments of the South China Sea is higher than that in the Gulf. This mineral appears to have been supplied from Borneo as well as the Mekong Delta. However, chlorite which shows a similar distribution to that of illite in sediments of the Gulf and the South China Sea has not indicated Borneo Isl. as a principal source area for chlorite. Greater resemblance in amount of kaolinite in both sediments of the Gulf and the South China Sea is due to the prevailing distribution of kaolinite as low latitude clay mineral on the bordering land areas. The distribution of clay minerals in sediments of the study area appears to be closely related to the soil formation and geology of the adjacent land areas.This work was carried out at Geological and Mineralogical Institute, Tokyo University of Education.  相似文献   

19.
The North-Andean subduction zone generates recurrent tsunamigenic earthquakes. The seismicity is usually considered to be segmented because of different specific morphological features of the Nazca Plate driving the subduction motion. Most of the recent powerful earthquakes in the margin were located in its northern part. To the south, the region of the Gulf of Guayaquil, only (undocumented) three events in 1901, 1933 and 1953 were possibly powerful and tsunamigenic. Here we are interested in the tsunami signature due to local seismicity. Two realistic earthquake scenarios (Mw = 7 and Mw = 7.5) taking into account the hypothesized segmentation of the area are proposed. Their return period is supposed to be intra-centenary. Then, a larger magnitude unsegmented Mw = 8 scenario is computed (half-millennium return period). The interior of the Gulf of Guayaquil as well as the Santa Elena Peninsula are sheltered areas including numerous coastal infrastructures and the city of Guayaquil. It is predicted that potential flooding would occur at high tide only for both segmented and unsegmented scenarios in (1) south of Playas with however only a few centimeters of wave height and (2) Chanduy (a few meters). Both are important zones of coastal farms.  相似文献   

20.
This Florida Geological Survey U.S. Department of the Interior, Minerals Manage ment Service Cooperative Study provides baseline data for major and trace metal concentrations in the sediments of the Steinhatchee River estuary. These data are intended to provide a benchmark for comparison with future metal concentration data measurements. The Steinhatchee River estuary is a relatively pristine bay located within the Big Bend Wildlife Management Area on the North Central Florida Gulf of Mexico coastline. The river flows 55 km through woodlands and planted pines before emptying into the Gulf at Deadman Harbor. Water quality in the estuary is excellent at present. There is minimal development within the watershed. The estuary is part of an extensive system of marshes that formed along the Florida Gulf coast during the Holocene marine transgression. Sediment accretion rate measurements range from 1.4 to 4.1 mm yr on the basis of lead-210 measurements. Seventy-nine short cores were collected from 66 sample locations, representing four lithofacies: clay- and organic-rich sands, organic-rich sands, clean quartz sands, and oyster bioherms. Samples were analyzed for texture, total organic matter, total carbon, total nitrogen, clay mineralogy, and major and trace-metal content. Follow ing these analyses, metal concentrations were normalized against geochemical reference elements (aluminum and iron) and against total weight percent organic matter. Metals were also normalized granulometrically against total weight percent fines (0.062 mm). Concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) for all metals except mercury. Mercury concentrations were determined by cold-flameless atomic absorption spectrometry (AAS). Granulo metric measurements were made by sieve and pipette analyses. Organic matter was determined by two methods: weight loss upon ignition and elemental analysis (by Carlo-Erba Furnace) of carbon and nitrogen. X-ray diffraction was used to deter mine clay mineralogy. Trace-metal concentrations were best correlated when normalized with respect to sediment aluminum concentrations. Normalizations indicate that most major and trace-metal concentrations fall within 95 % prediction limits of the expected value. This finding suggests that little significant metal contamination occurred within this system prior to 1994 sediment sampling. Exceptions include lead, mercury, copper, zinc, potassium, and phosphorous. Lead and mercury are elements that generally enter this watershed through atmospheric deposition; thus, anomalous levels of these metals are not necessarily associated with activities within the watershed of the Steinhatchee River estuary. Anomalous concentrations of other metals such as zinc, copper, and phosphorous probably do originate within the Steinhatchee watershed. Copper failed to correlate well with any geochemical or granulometric normalizer, and this condition was not limited to a single facies or area within the estuary. This finding may indicate copper contamination in the system. Increased zinc and copper levels may be attributed to marine paints. Phosphorous levels also appeared to be elevated in a few locations in the two marsh facies sampled. This may be due to nutrient loading from two small communities, Jena and Steinhatchee, or from the application of this element in fertilizer to reduce moisture stress to young planted pines on tree farms within the watershed.  相似文献   

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