Summary of 25 Years of Xylem Tracheids and Sewage/Sludge in the Sea

The Rapid Sewage/Sludge Indicator Technique (RSIT), developed during the early 1970's, responded to critical needs within the Bureau of Water Pollution Control. It enabled quick detection of contamination in ocean water and bottom sediments during sewage-related emergencies and routine monitoring. RSIT became an invaluable tool for resource management, in determining where and to what extent marine environments are impacted, and when immediate information is necessary for public health decisions.

The RSIT utilizes microscopic examination for terrestrial plant vascular tissue, especially the xylem tracheid elements, as identifiers of sewage/sludge. Not normally found in ocean waters, this material, in toilet paper and the roughage of the human diet which passes through the digestive system intact, is an indicator of human faecal contamination. Minimal training and common laboratory materials allow gross screening in five minutes. New studies by the United States Environmental Protection Agency (USEPA), United States Geologic Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA), most recently at the 106-mile dump site off the New York Bight, revalidated the technique as a rapid, inexpensive, easy to use, semiquantitative indicator both for water column and sediment samples.     

Formation of Two Xylem Frost Injuries in One Annual Ring in Siberian Spruce under Conditions of Western Siberian Forest-Tundra

The phenomenon of the formation of two damaged xylem layers in one frost ring is described in Siberian spruce grown in western Siberian forest-tundra. Temperature conditions providing for the formation of pathological cell and tissue structures are determined. The relationship between the formation of double frost injuries and cold periods is demonstrated.     

Effects of elevated pO3 on carbon cycle between above and belowground organs of trees

Translocation of carbohydrate from leaves to roots via phloem and reallocation from roots to leaves via xylem regulate the allocation of carbon （C） between above and belowground organs of trees. To quantitatively analyze effects of elevated ozone concentrations pO3 on the internal cycle of C, juvenile beech and spruce were grown in phytotrons and exposed to ambient and elevated pO3 （i.e. twice-ambient O3 levels, restricted to 〈 150 ppb） for two growing seasons. The translocation of C in the phloem and xylem was quantitatively studied by investigating the phloem/xylem-loading of sugars, the differentiation of stem conductive tissue and the hourly water flow through the stem. Results in the present study shown, elevated pO3 significantly decreased C translocation from shoot to roots in beech by reducing both sugar concentration in the phloem and conductive phloem area. Elevated pO3 also significantly decreased C reallocation from the roots to the shoot in beech by reducing both of sugar concentration in the xylem and transpiration rate. The adverse effects of elevated pO3 on C translocation in the phloem and xylem, however, were small in spruce. Contrasting to beech, spruce is less sensitive to elevated pO3, regarding to phloem differentiation and sugar concentrations in the phloem and xylem.     

Summary of 25 Years of Xylem Tracheids and Sewage/Sludge in the Sea

The Rapid Sewage/Sludge Indicator Technique (RSIT), developed during the early 1970′s, responded to critical needs within the Bureau of Water Pollution Control. It enabled quick detection of contamination in ocean water and bottom sediments during sewage-related emergencies and routine monitoring. RSIT became an invaluable tool for resource management, in determining where and to what extent marine environments are impacted, and when immediate information is necessary for public health decisions.

The RSIT utilizes microscopic examination for terrestrial plant vascular tissue, especially the xylem tracheid elements, as identifiers of sewage/sludge. Not normally found in ocean waters, this material, in toilet paper and the roughage of the human diet which passes through the digestive system intact, is an indicator of human faecal contamination. Minimal training and common laboratory materials allow gross screening in five minutes. New studies by the United States Environmental Protection Agency (USEPA), United States Geologic Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA), most recently at the 106-mile dump site off the New York Bight, revalidated the technique as a rapid, inexpensive, easy to use, semiquantitative indicator both for water column and sediment samples.     

Heavy Metal Content in Xylem Sap (Vitis Vinifera) from Mining and Smelting Areas

No data are available on the content of heavy metals in the xylem sap of grapevines growing in contaminated areas. The aim of this work was to obtain data on the concentration of Pb, Zn, Cd and Cu in the xylem sap of grapevine (Vitis vinifera) cultivar Monica (ungrafted), growing near contaminated sites: a smelter, an abandoned and an active mine, and to investigate relationships between xylem sap mineral composition and the heavy metal content of the soil. The concentrations of Pb, Zn, Cd and Cu in the sap were enhanced compared to that of the soil, ranging from 4.3 to 611.4 µg Pb , 801 to 6176 µg Zn , 2.5 to 45 µg Cd and 19.8 to 161 µg Cu . Dry matter of xylem sap was significantly related to the heavy metals content in xylem saps, but no significant relationship between the metals in sap and total and DTPA/TEA extractable metal fraction in soil was found.     

Effects of used lubricating oil on two mangroves Aegiceras corniculatum and Avicennia marina

An outdoor experiment was set up to investigate the effects of used lubricating oil(5 L/m~2)on Aegiceras corniculatum Blanco. and Avicennia marina(Forsk)Vierh.,two salt-excreting mangroves.A.marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling.When treated with canopy-oiling,half of A.corniculatum plants survived for the whole treatment time(90 d);but,for A.marina,high mortality (83%)resulted from canopy-oiling within 3 weeks and no plants survived for 80 d.Base-oiling had no lethal effects on A.corniculatum plants even at the termination of this experiment,but 83% of A.marina plants died 80 d after treatment.Forty days after canopy- oiling,93% ofA.corniculatum leaves fell and no live leaves remained on A.marina plants.By the end of the experiment,base-oiling treatment resulted in about 45% ofA.corniculatum leaves falling,while all A.marina leaves and buds were burned to die.Lubricating oil resulted in physiological damage to A.corniculatum leaves,including decreases in chlorophyll and carotenoid contents,nitrate reductase,peroxidase and superoxide dismutase activities,and increases in malonaldehyde contents.For both species,oil pollution significantly reduced leaf,root,and total biomass,but did not significantly affect stem biomass.Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.     

Tracing the behaviour of hexachlorobenzene in a paddy soil-rice system over a growth season

Hexachlorobenzene (HCB), a persistent organic pollutant (POP), has been found in paddy soils. To improve the understanding of HCB contamination in paddy soils, a laboratory simulative study was carried out to investigate the behavior of HCB in a paddy soil and rice plants. This study was divided into three experiments. First, an experiment aimed to examine the evaporation of HCB in paddy soil. In the second experiment, rice was planted in 10 mg/kg HCB contaminated soil and after pot culture at 3, 6, 9, and 27 weeks (at maturity), both soil and plant samplings were scheduled to be sampled. The soil samples comprised rhizosphere soil, nonrhizosphere soil, and unplanted contaminated soil, whereas plant samples included shoots, roots, and rice grains (dehusked). Lastly, in this part, HCB in xylem saps was designed to be examined. The results showed that (1) the HCB translocation from paddy soil to rice by vaporization; (2) the HCB concentration in rice grains was surprisingly high; (3) the observed HCB decrease in rice rhizosphere offers a potential means for in situ HCB degradation; (4) HCB might not be transported along transpiration in rice.     

树干深层理植铁剂“颗颗灵”后效研究

本文测定了成都市龙泉山缺铁失绿症果树埋植铁剂“颗颗灵”三年后叶片的叶绿素含量、厚度、100叶重、100叶体积、100叶面积等叶片生理和生长指标的变化。结果表明，树干深层埋植铁剂“颗颗灵”对供试桃、李、樱桃和柑桔树具有持续的后效．