深圳市重型与轻型屋顶绿化降温增湿效应研究

应用比较研究法评估了重型屋顶花园与轻型屋顶绿化的降温增湿效应。观测结果表明,重型和轻型屋顶绿化在夏季均能有效地降低屋面高温、增加屋面相对湿度,且重型屋顶花园的降温增湿效应明显优于轻型屋顶绿化。为屋顶花园的发展提供参考。     

荆州市绿地系统分析与发展对策探讨

分析了荆州市绿地系统现状及存在问题,并针对荆州市的城市特点,从绿地的布局结构、高质量绿地建设和保证体系3方面,探讨了荆州市城市绿地系统建设的可持续发展之路。     

沈阳市绿色食品发展现状及应对措施研究

论述了沈阳市绿色食品发展的现状与存在的主要问题,以及发展绿色食品产业的重大意义,并根据发展绿色食品存在的主要问题,提出了对策与建议。     

Estimating N status of winter wheat using a handheld spectrometer in the North China Plain

Excessive nitrogen (N) fertilizer application is very common in the North China Plain. Diagnosis of in-season N status in crops is critical for precision N management in this area. Remote sensing, as a timely and nondestructive tool, could be an alternative to traditional plant testing for diagnosing crop N status. The objectives of this study were to determine which vegetation indices could be used to estimate N status in winter wheat (Triticum aestivum L.) under high N input conditions, develop models to predict winter wheat N uptake using spectral vegetation indices and validate the models with data from farmers’ fields. An N rate experiment and a variety-N experiment were conducted in Huimin, Shandong Province from 2005/2006 to 2006/2007 to develop the models. Positive linear relationships between simple ratio vegetation indices (red vegetation index, RVI and green vegetation index, GVI) and N uptake were observed independent of growth stages and varieties (R², 0.48–0.74). In contrast, the relationships between normalized difference vegetation indices (NDVI and GNDVI), red and green normalized difference vegetation index (RGNDI), and red and green ratio vegetation index (RGVI) were exponentially related to N uptake (R², 0.43–0.79). Subsequently, 69 farmers’ fields in four different villages were selected as datasets to validate the developed models. The results indicated that the prediction using RVI had the highest coefficient of determination (R², 0.60), the lowest root mean square error (RMSE, 39.7 kg N ha⁻¹) and relative error (RE, 30.5%) across different years, varieties and growth stages. We conclude that RVI can be used to estimate nitrogen status for winter wheat in over-fertilized farmers’ fields before heading.     

海口市城市道路绿地景观特色探析

以文献和实例结合的方式简述海口市城市道路绿地建设概况、形成历程及主要特点,探析其绿地景观特色,以期对城市道路绿地建设有所帮助。     

麦绿素在国内的研究进展

随着人们健康意识的不断提高,作为一种天然绿色保健产品,麦绿素产品越来越受到人们的青睐。在国内,麦绿素产品也引起科研工作者的高度重视。近年来,我国科研工作者对麦绿素产品的原料来源、生产工艺、麦绿素的活性成分,以及麦绿素的生理功能都进行了大量的实验研究,为麦绿素产品的生产和临床应用提供了科学的实验数据和技术支持。从原料来源、主要成分、生理功能和生产工艺等方面记述了麦绿素产品在国内的研究状况以及取得的研究成果,并提出了麦绿素研究今后要注重的一些问题和研究方向。     

Quantitative resistance to symptomless growth of Leptosphaeria maculans (phoma stem canker) in Brassica napus (oilseed rape)

Quantitative resistance to Leptosphaeria maculans in Brassica napus was investigated in field and controlled environments using cultivars Darmor (with quantitative resistance) and Eurol (without quantitative resistance). In field experiments, numbers of phoma leaf spot lesions in autumn/winter and severity of stem canker the following summer were assessed in three growing seasons. There were no differences between Darmor and Eurol in number of leaf lesions in autumn/winter. However, stem cankers were less severe on Darmor than Eurol at harvest the following summer. In controlled-environment experiments, development of leaf lesions at different temperatures (5–25°C) and wetness durations (12–72 h) was investigated using ascospore inoculum; symptomless growth of L. maculans along leaf petioles towards the stem was quantified using quantitative PCR and visualized using GFP-expressing L. maculans ; growth of L. maculans within stem tissues was investigated using GFP-expressing L. maculans . There were more leaf lesions on Darmor than Eurol, although there was no difference between Darmor and Eurol in L. maculans incubation period. There were no differences between Darmor and Eurol in either distance grown by L. maculans along leaf petioles towards the stem or quantity of L. maculans DNA in leaf petioles, but L. maculans colonized stem tissues less extensively on Darmor than Eurol. It was concluded that quantitative resistance to L. maculans operates during colonization of B. napus stems by the pathogen.     

Dissipation of acephate, chlorpyrifos, cypermethrin and their metabolites in a humid-tropical vegetable production system

BACKGROUND: High amounts of insecticides are often used in intensive tropical vegetable production systems. Their persistence and residues in vegetables and soils need to be studied to ensure food safety and environmental stability. The dissipation of acephate, chlorpyrifos, cypermethrin and their metabolites was studied in green mustard [Brassica juncea (L.) Coss.] and soils. Two treatments, Impact 75 (acephate) and Agent 505 (cypermethrin plus chlorpyrifos), were applied 4 times at weekly intervals. RESULTS: Dissipation of acephate, chlorpyrifos and cypermethrin in green mustard and topsoils followed first‐order kinetics, with half‐lives of between 1.1 and 3.1 days in green mustard and between 1.4 and 9.4 days in topsoils (26 °C). Higher vapour pressure of insecticides and higher rainfall appeared to stimulate dissipation from the vegetable, with least effect of rainfall on chlorpyrifos. Dissipation rates in the vegetable were faster or similar (cypermethrin) to rates observed for temperate areas. Preharvest intervals of 13, 4 and 3 days were required for acephate, chlorpyrifos, cypermethrin and their metabolites to comply with the tolerance levels. The pesticide dissipation rates in soils varied by less than a factor of 3 between sites. The metabolites methamidophos and TCP derived from acephate and chlorpyrifos amounted to less than 10 and 25% by mass of the parent compounds in soils. Vegetable shading possibly retarded pesticide degradation in soil. CONCLUSION: The dissipation of pesticides and their metabolites in the vegetable was rapid and faster than the dissipation in temperate climates. The degradation rates of pesticides in the soil were equal to or slightly faster than the degradation rates in temperate soils. Copyright © 2008 Society of Chemical Industry     

杨凌分类绿地园林树种规划研究

杨凌分类绿地园林树种规划涉及到企事业单位绿地、城区绿地、乡村田园、防护林等,实行城乡大环境一体化绿化建设,形成点、线、面、网、片的生态园林体系。西北林学院学报22卷第6期辛转霞等杨凌分类绿地园林树种规划研究     

城乡一体化小城镇绿地系统规划初探——以哈尔滨市团结镇为例

本文以哈尔滨市团结镇为例,从生态环境建设的角度将镇域内的以植物为主体的用地统一到小城镇的绿地系统中,在加强镇区绿地规划的同时,将镇域内的农田林地等进行合理的组织和利用。进行城乡一体化小城镇绿地系统规划初探,体现小城镇的可持续发展。