Effects of elevated atmospheric O3 concentrations on early and late leaf growth and elemental contents of Acer truncatum Bung under mild drought

To investigate the possible interactive effects of elevated atmospheric ozone (O₃) concentrations and periodic drought stress on physiology of Shantung maple (Acer truncatum Bung), an experiment was conducted from the growth season of 2012 to 2013 with open-top chambers (OTCs) in Changping district, a suburb of Beijing, China. Four treatments were administered with three replications in twelve OTCs which were NN (well watered + ambient air), NO (well watered + add 100 nl l^? 1 O₃ above ambient air), DN (drought stress + ambient air) and DO (drought stress + add 100 nl l^? 1 O₃ above ambient air). Leaf area (LA), leaf mass per area (LMA), individual leaf weight (ILW), carbon(C), nitrogen (N) and sulfur (S) contents in early and late leaves were measured at the end of the second year. The results showed: (1) Both elevated O₃ concentration and drought treatments significantly reduced early leaf LMA, LA, ILW, leaf N and S contents, with a reduction of 28.7, 45.7, 61.3, 39.6, 16.1% by O₃ stress and 12.5, 46.8, 53.5, 15.45 and 22% by drought stress, respectively, while only LMA of late leaf was reduced 12.1% by O₃ treatments and LA and ILW were significantly reduced 23.3% and 30% by drought treatments. (2) Significant interactions of elevated atmospheric O₃ concentration and mild drought were detected on LMA, LA, ILW, N and C contents in early leaves and LMA in late leaves. Except for LA, the decreases under interactive treatments were all less than independent O₃ effects. In conclusion, late leaf had less responses to elevated O₃ and drought stresses than early leaves which need to be considered separately. The interactive effects suggested drought had antagonistic effects with O₃ on growth indicators except for LA, indicating drought could mitigate the adverse efforts from O₃ effects.     

Monthly variations in calix growth, polyp tissue, and density banding of the Mediterranean scleractinian Cladocora caespitosa (L.)

Monthly skeletal growth of the scleractinian, temperate coral Cladocora caespitosa (L.) from the Ligurian Sea (NW Mediterranean) was analysed for a period of 1 year and compared with seawater parameters. Measurements on corallite sections and on X-ray images showed that the formation of the high-density (HD) band and two dissepiments are favoured by fall–winter conditions, characterised by high quantities of rain, rough seas, and cold seawater. In summer, when the low-density (LD) band is formed, the corallites stretch upward and form one new dissepiment and one deep calix, where the polyps recede almost completely in August. These findings confirmed the adaptation of the temperate coral to winter environmental conditions, characterised by low irradiance and high availability of nutrients and food particles resuspended from bottom sediments. On the contrary, the high seawater temperature, irradiance, and ammonia contents stressed the coral in August and, when they persist in September, may cause the onset of mortality events.     

New Phospholipase A<Subscript>1</Subscript>-producing Bacteria from a Marine Fish

Phospholipase A1 is a hydrolytic enzyme that catalyzes the removal of the acyl group from position 1 of glycerophospholipids to form 2-acyl lysophospholipids. Lysophospholipids are used in foods, cosmetics, and pharmaceuticals as surfactants. Novel forms of phospholipase A1 that function at low temperatures are desirable for use in lipophilic systems in food processing. However, there is currently little variety in the available sources of phospholipase A1. Given this situation, we screened the intestinal contents of marine animals for phospholipase A1-producing bacteria. Colonies that formed a halo on K28CP screening medium and that grew in K28 medium were cultured in liquid K28 medium, and the supernatant was retrieved for analysis. Phosphatidylcholine was added to the culture supernatant, and the product of the reaction was analyzed by using TLC. For culture supernatants that were able to generate lysophosphatidylcholine, synthetic phosphatidylcholines were added, and the site of the reaction was determined by analyzing the fatty acid compositions of the lysophosphatidylcholines generated by GLC. A bacterial isolate from a flatfish, which we named HFKI0020, was found to have phospholipase A1 activity at low temperatures. We determined that the isolate HFKI0020 is closely related to Pseudomonas by using 16S rDNA sequence analysis and by characterizing the isolate with respect to its physiologic and biochemical properties. From the intestinal contents of a marine fish, we successfully isolated a bacterium that secretes phospholipase A1 that is active at low temperatures.     

不同预处理及发酵方式对提高蔗渣发酵产物蛋白含量的研究

采用不同的预处理方法对蔗渣进行预处理,并测定了其各个组分的含量。利用霉菌对蔗渣进行微生物降解,并讨论了不同发酵方式对产物中蛋白含量的影响。结果表明,木霉与热带假丝酵母共发酵时蛋白含量最高,为17．74％。     

华南阔叶树种幼苗叶片的养分特征

研究了阔叶树种幼苗山杜英、红锥、海南红豆、火力楠、红花油茶、枫香、黎蒴、米老排和樟树的N、P、K浓度和单位叶面积含量。结果表明,海南红豆、黎蒴和樟树的N、P、K浓度较高,而红花油茶、黎蒴和樟树的单位叶面积N、P、K含量较高,9种树种的上部和下部叶片的平均养分浓度分别为N16．67和17．09g·kg^-1,P1．29和0．84g·kg^-1,K11．77和6．65g·kg^-1,平均养分含量分别为N0．871和1．069g·m^-2,P0．065和0．052g·m^-2,K0．608和0．426g·m^-2,各树种上部叶片的P和K浓度和含量大于下部叶片,从养分含量的角度考虑,红花油茶与其他8种树种混交,红锥或米老排与山杜英、枫香、海南红豆、黎蒴、樟树混交,火力楠与黎蒴、樟树混交是合理的。     

生态恢复经济学

在总结国内外关于生态恢复经济理论研究进展的基础上, 提出了生态恢复经济学的学科含义、地位、特点和研究对象.生态恢复经济学是研究退化生态系统退化过程中的经济损失、退化生态系统恢复期间的成本效益以及恢复过程中的经济价值动态变化的一门交叉性学科.它以人类可持续利用为核心,研究生态系统退化、恢复和重建过程中生态系统与经济系统之间客观运动规律及其机理的一门科学.生态恢复经济学具有综合性和实践性的特点,它是生态经济学和恢复生态学的重要分支学科,在生态经济学理论体系中具有特别重要的地位.     

土壤干旱胁迫对紫叶矮樱叶片呈色的影响

以盆栽3 a紫叶矮樱叶片为试材,采用称重控水法,设对照(土壤含水量18.11%)、轻度干旱(土壤含水量14.72%)、中度干旱(土壤含水量11.32%)和重度干旱(土壤含水量7.92%)4个处理组,研究不同土壤干旱条件下紫叶矮樱叶片呈色色素含量、可溶性糖含量、PAL酶活性的变化规律及其对叶片呈色的影响.结果表明:轻度干旱,随胁迫时间的延长叶片中花青苷、类黄酮、叶绿素、可溶性糖含量、PAL酶活性和a*增加, L*和b*降低;中度和重度干旱,随胁迫时间的延长花青苷、类黄酮、叶绿素、类胡萝卜素、可溶性糖含量、PAL酶活性和a*先增加再降低,L*和b*先减小再增大.短时间的干旱能够提高紫叶矮樱的叶片色泽,中度干旱15 d或重度干旱12 d,是紫叶矮樱叶色发生明显转变的关键时期;花青苷含量的变化是影响紫叶矮樱叶色变化的主要原因.     

The diet of the badger Meles meles in the Republic of Ireland

The diet of the Eurasian badger (Meles meles) in the Republic of Ireland was studied by examination of the stomach contents of 686 badgers, collected between March 2005 and September 2006. It was found that the relative importance of different food types, as indicated by their frequency of occurrence and ingested bulk in the diet, fluctuated seasonally. Tipulid larvae (Cl. Insecta, Ord. Tipulidae) dominated the diet in spring; Anura (Cl. Amphibia) and Aculeata (Ord. Hymenoptera) during the summer; and Noctuid larvae (Cl. Insecta, Ord. Noctuidae) in autumn and winter. Thus this type of foraging behaviour supports the contention that badgers are generalist foragers with seasonal food preferences. This feeding behaviour is more similar to that of badgers in Italy and Spain than to badgers in England.