Survival and Growth of Isolated Polyps of Galaxea fascicularis (Linnaeus 1767) on Six Kinds of Culture Substrates: Implications for Mariculture,Aquarium Culture,and Conservation

Coral aquaculture is viewed as a sustainable method of providing colonies for use in the aquarium trade, pharmacological studies, and coral reef rehabilitation. The production of large, healthy specimens depends on providing conditions that mimic or surpass natural reef environments. Materials with a high degree of variability in physical and chemical properties are utilized as substrates in coral aquaculture, but until fragment–substrate interactions are isolated and independently studied, the possible inhibitory and facilitative effects of each material will remain unclear. To understand potential key roles that substrates can play in coral culture, a comparison was made about the role of various materials on fragment survival and growth. The experiment examined the interactions between isolates of a common scleractinian coral, Galaxea fascicularis, and six commonly used substrates (coral rock, terracotta, polyvinyl chloride, steel, rubber tire, and concrete) and how these affected survival and growth. No differences were observed in the survival, colony size, and polyp production of the resulting microcolonies. The results show that, for G. fascicularis, growth is not affected by substrate type. The results demonstrate the use of a wide variety of materials for the successful aquaculture of scleractinian corals.     

透气型砂栽培研究进展与前景分析

透气型砂栽培（Sandponics）是生态环保、低成本、低技术的无土栽培技术,符合当前中国国情和世界无土栽培发展趋势。阐明透气型砂栽培系统的组成结构,提出透气型砂栽培基质的粒径、含盐量、含泥量和酸碱度等理化指标,探讨砂栽培营养液元素种类和要求,分析透气型砂栽培生产可持续性理论基础,建立透气型砂栽培技术标准,为透气型砂栽培的进一步研究和生产实践提供参考。分析透气型砂栽培蔬菜产品的含糖量、亚硝酸盐含量、重金属含量等营养品质。总结透气型砂栽培的特点和所具备的生态意义、社会意义,分析透气型砂栽培在都市农业和南海岛屿蔬菜生产实践中的应用前景。     

水稻育苗基质可持续利用研究现状及建议对策

水稻育苗基质的可持续利用不仅关乎水稻生产,同时直接关系农业经济发展。辽宁作为北方粳稻主要产区,在当前大力发展水稻工厂化育苗的条件下,开展新型育苗基质的研发、示范与推广,是解决当前水稻育苗可持续利用的有效途径,也是今后水稻生产的发展趋势,     

金针菇菌渣有机肥对棉花产量及经济效益影响

以棉花为材料，在山东省德州市平原县前曹镇进行小区试验，试验共设菌渣有机肥作基肥、与化肥不同比例配施和农民习惯性施肥7个处理，研究施用金针菇菌渣有机肥对棉花产量及经济效益的影响。结果表明，菌渣有机肥可替代化肥在棉花上做基肥施用，可促进棉花增产，菌渣有机肥配合化肥使用效果较好，施用3000kg·hm-2菌渣有机肥和187．5kg·hm-2复合肥（15：15：15）的处理最佳，比农民习惯施肥增产8．2％，效益提高9．6％。     

不同育苗基质对须弥红豆杉幼苗根系生物量的影响研究

使用4种不同育苗基质进行须弥红豆杉育苗试验,通过分析不同基质小苗(1 a龄)根系生物量状况,选出最适合红豆杉根系生长的育苗基质.结果表明,用腐殖土(50%)+红土(50%)做基质较适合须弥红豆杉苗木粗根生长,用腐殖土做基质较适合须弥红豆杉苗木细根生长,这2种育苗基质在云南省来源广泛,成本低廉,可在须弥红豆杉育苗中推广使用,丹麦基质最不利于须弥红豆杉苗木的根系生长.     

Optimization of hydrolytic and oxidative enzyme methods for ecosystem studies

Microbial digestive enzymes in soil and litter have been studied for over a half century, yet the understanding of microbial enzymes as drivers of ecosystem processes remains hindered by methodological differences among researchers and laboratories. Modern techniques enable the comparison of enzyme activities from different sites and experiments, but most researchers do not optimize enzyme assay methods for their study sites, and thus may not properly assay potential enzyme activity. In this review, we characterize important procedural details of enzyme assays, and define the steps necessary to properly assay potential enzyme activities in environmental samples. We make the following recommendations to investigators measuring soil enzyme activities: 1) run enzyme assays at the environmental pH and temperature; 2) run proper standards, and if using fluorescent substrates with NaOH addition, use a standard time of 1 min between the addition of NaOH and reading in a fluorometer; 3) run enzyme assays under saturating substrate concentrations to ensure V_max is being measured; 4) confirm that product is produced linearly over the duration of the assay; 5) examine whether mixing during the reaction is necessary to properly measure enzyme activity; 6) find the balance between dilution of soil homogenate and assay variation; and 7) ensure that enzyme activity values are properly calculated. These steps should help develop a unified understanding of enzyme activities in ecosystem ecology.     

1980 tephra from Mount St. Helens: Spatial and temporal variation beneath forest canopies

Summary Tephra and underlying litter and soil were sampled in 1980, 1982, and 1987 beneath subalpine forests where 4.5 and 15 cm of tephra fell during the 1980 eruption of Mount St. Helens, Washington State, USA. Coarse pumice had a higher initial pH and less total N, less exchangeable K, Ca, and Mg, and less extractable B and S than finer textured layers. Tephra pH and concentrations of cations and S decreased rapidly with time, especially during the first 2 years in the finer layers. Total N, Bray-Kurtz P, and organic C concentrations in the tephra increased with time. Changes within a site in total N, pH, organic C, P, Ca, Mg, and S from 1980 to 1987 exceeded the differences among sites at any one time. By 1987 a forest floor covered much of the tephra surface, and differences in Ca associated with site vegetation and seepage had developed in tephra layers of a similar depth. In 15 cm deep tephra at one site in 1987, the tephra crust beneath the forest canopy was thicker and had higher concentrations of coarse particles, organic C, total N, and cations than beneath forest openings. In concave microsites the crust was thicker, with higher pH, organic C, and total N but lower S than in adjacent convex microsites. Spatial and temporal chemical differences are sufficient to affect patterns of vegetation recovery.     

培养基质对丛枝菌根(AM)真菌生长发育的影响

温室条件下，以盆栽培养方法研究不同培养基质对丛枝菌根(Arbuscular Mycorrhizae,AM)真菌Glomus mosseae生长发育的影响。结果表明：不同理化性质的基质对菌根共生体生长发育的影响不同，综合考虑菌根长度、根外菌丝量及孢子数3项指标,以沙土混合物(体积比3∶1)对G. mosseae菌剂的生长发育最为有利。宿主植物菌根长度及根中的可溶性糖浓度与根外孢子数有正相关关系，而宿主植物中磷浓度与菌根真菌的生长发育也有类似的关系。说明培养基质的养分状况、水分状况、通气状况等诸多因素都会影响菌根共生体的建立和发展。宿主植物的菌根长度、根中可溶性糖浓度以及宿主植物磷浓度对菌根真菌的生长发育有显著影响。因此，工厂化AM菌剂生产中，应以沙土混合物(体积比3∶1)为生产G. mosseae菌剂的培养基质。     

Atmospheric nitrate deposition and the microbial degradation of cellobiose and vanillin in a northern hardwood forest

Human activity has increased the amount of N entering terrestrial ecosystems from atmospheric NO₃⁻ deposition. High levels of inorganic N are known to suppress the expression of phenol oxidase, an important lignin-degrading enzyme produced by white-rot fungi. We hypothesized that chronic NO₃⁻ additions would decrease the flow of C through the heterotrophic soil food web by inhibiting phenol oxidase and the depolymerization of lignocellulose. This would likely reduce the availability of C from lignocellulose for metabolism by the microbial community. We tested this hypothesis in a mature northern hardwood forest in northern Michigan, which has received experimental atmospheric N deposition (30 kg NO₃⁻-N ha⁻¹ y⁻¹) for nine years. In a laboratory study, we amended soils with ¹³C-labeled vanillin, a monophenolic product of lignin depolymerization, and ¹³C-labeled cellobiose, a disaccharide product of cellulose degradation. We then traced the flow of ¹³C through the microbial community and into soil organic carbon (SOC), dissolved organic carbon (DOC), and microbial respiration. We simultaneously measured the activity of enzymes responsible for lignin (phenol oxidase and peroxidase) and cellobiose (β-glucosidase) degradation. Nitrogen deposition reduced phenol oxidase activity by 83% and peroxidase activity by 74% when compared to control soils. In addition, soil C increased by 76%, whereas microbial biomass decreased by 68% in NO₃⁻ amended soils. ¹³C cellobiose in bacterial or fungal PLFAs was unaffected by NO₃⁻ deposition; however, the incorporation of ¹³C vanillin in fungal PLFAs extracted from NO₃⁻ amended soil was 82% higher than in the control treatment. The recovery of ¹³C vanillin and ¹³C cellobiose in SOC, DOC, microbial biomass, and respiration was not different between control and NO₃⁻ amended treatments. Chronic NO₃⁻ deposition has stemmed the flow of C through the heterotrophic soil food web by inhibiting the activity of ligninolytic enzymes, but it increased the assimilation of vanillin into fungal PLFAs.     

不同栽培基质对番茄植株长势、果实品质及产量的影响

试验以土壤、菇渣:砂=3:1和菇渣:砂:鸡粪=4:2:1为栽培基质,采用定期浇灌营养液的方式来栽培番茄,研究了不同栽培基质对其植株长势、果实品质及产量的影响。结果表明:与土壤相比,菇渣:砂=3:1和菇渣:砂:鸡粪=4:2:1基质栽培有利于株高生长和茎的增粗,但对叶绿素含量影响不大;菇渣:砂=3:1的植株地上部和地下部全氮和全磷含量均显著高于其它处理;土壤的植株地上部和地下部全钾含量均显著高于其它处理;单果重和单株平均产量以菇渣:砂:鸡粪=4:2:1最高;糖酸比由高到低的顺序为:菇渣:砂:鸡粪=4:2:1>菇渣:砂=3:1>土壤,VC含量由大到小的顺序为:菇渣:砂=3:1>菇渣:砂:鸡粪=4:2:1>土壤。综合3种栽培基质对番茄植株生长、果实品质和产量等指标的影响,菇渣:砂:鸡粪=4:2:1为番茄基质栽培的最优组合。