Die Leitfähigkeit von Fichtenborken-Extrakten als empfindlicher Indikator für Luftverunreinigungen

The Conductivity of Bark-Extracts from Spruce, a Sensitive Indicator for Air Poilution . Bark of spruce is a useful and sensitive indicator for air pollution. The latter may be determined more precisely by electrolytic conductivity of bark extracts than by pH-value or sulphate level of foliage. By an additional simple sulphate analysis of bark extracts the effects of SO₂ may be distinguished from those of certain components in dust.     

数字林业在天然林保护工程中的应用研究

本文阐述了数字林业的概念及涵义,指出其最初的切入点是国家林业局提出的六大林业生态工程。针对天然林保护工程的现状,提出用数字林业技术解决其存在的问题,构建了基于3S技术的天然林保护工程管理地理信息系统,使天然林保护工程的管理步入规范化、科学化、现代化的轨道。     

Cytotoxic pentacyclic triterpenes from Combretum nigricans

A new pentacyclic triterpene, 11alpha-acetoxy-20,24-epoxy-25-hydroxy-dammar-3-one (1), has been isolated from the African tree Combretum nigricans, together with the known corresponding diol, 20,24-epoxy-11alpha, 25-dihydroxy-dammar-3-one (2). They are responsible, at least in part, for the cytotoxic activity of the methanolic extract of the plant.     

Sensitivity of fungi isolated from onychomycosis to Eugenia cariophyllata essential oil and eugenol

The antifungal activity of Eugenia cariophyllata essential oil and eugenol, its major constituent, on fungal strains isolated from onychomycosis was evaluated. The natural products presented prominent antifungal action with MIC of 1% and 4%, respectively.     

Antimicrobial flavonoids from the stem bark of Erythrina burttii

The chloroform extract of the stem bark of Erythrina burttii showed antifungal and antibacterial activities using the disk diffusion method. Flavonoids were identified as the active principles. Activities were observed against fungi and Gram(+) bacteria, but the Gram(-) bacteria Escherichia coli was resistant.     

Reinvestigation of the proteolytically active components of Bromelia pinguin fruit

Pinguinain is the name given to a proteolytic enzyme preparation obtained from Bromelia pinguin fruits that has been scarcely studied. The present paper deals on the reexamination of the proteases present in fruits of B. pinguin grown in Cienfuegos, Cuba. The preparation (partially purified pinguinain, PPP) showed the main characteristics of the cysteine proteases, i.e., optimum pH within alkaline range (pH 7.2-8.8), inhibition of proteolytic activity by thiol blocking reagents, which is usually reverted by addition of cysteine, a remarkable thermal stability and notable stability at high ionic strength values. Isoelectric focusing and zymogram of PPP revealed the presence of several proteolytic components between pI 4.6 and 8.1. Preliminary peptidase purification by cationic exchange chromatography showed the presence of two main proteolytic fractions with molecular masses of approximately 20.0 kDa, according to SDS-PAGE.     

杜仲生长节律与施肥技术简报

杜仲高生长以4－7月份生长最快，6月份达最高峰；径生长以5－7月为旺盛期，其中6、9月各有一次生长高峰；杜仲林地施肥以4－5月为最佳；施肥量为一个区间，且因树龄而异；施肥按坡台地和平地进行沟施和穴施。     

Variations in dark respiration and mitochondrial numbers within needles of Pinus radiata grown in ambient or elevated CO2 partial pressure

Within-leaf variations in cell size, mitochondrial numbers and dark respiration rates were compared in the most recently expanded tip, the mid-section and base of needles of Pinus radiata D. Don trees grown for 4 years in open-top chambers at ambient (36 Pa) or elevated (65 Pa) carbon dioxide partial pressure (p(CO2)a). Mitochondrial numbers and respiratory activity varied along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Regardless of the location of the cells (tip, middle or basal sections), needles collected from trees grown in elevated p(CO2)a had nearly twice the number of mitochondria per unit cytoplasm as those grown in ambient p(CO2)a. This stimulation of mitochondrial density by growth at elevated p(CO2)a was greater at the tip of the needle (2.7 times more mitochondria than in needles grown in ambient CO2) than at the base of the needle (1.7 times). The mean size of individual mitochondria was unaffected either by growth at elevated p(CO2)a or by position along the needle. Tree growth at elevated p(CO2)a had a variable effect on respiration per unit leaf area, significantly increasing respiration in the tip of the needles (+25%) and decreasing respiration at the mid-section and base of the needles (-14% and -25%, respectively). Although a simple relationship between respiration per unit leaf area and mitochondrial number per unit cytoplasm was found within each CO2 treatment, the variable effect of growth at elevated p(CO2)a on respiration along the length of the needles indicates that a more complex relationship must determine the association between structure and function in these needles.     

杀虫灯已成为森林害虫综合治理的重要工具

近年来,以佳多频振式杀虫灯为代表的灯光诱杀器械,其技术性能得到较大改进和提高.在监测功能的基础上,作为诱杀工具,得到广泛认可,防治森林害虫范围不断扩展,防治面积越来越大,展现出广阔的应用前景.