龙头选购指南

走进建材城,各式各样的龙头让人眼花缭乱,款式有手按的、提拉的、旋转的、脚踏的、混水的、自动感应的很多种,适用地点还各不相同,价格也参差不齐,要想从中选购一款合适自己的产品还真不容易,所以请看以下选购龙头的小指南,希望能给你一些帮助。     

冬季肌肤养护

白皙美丽的肌肤是所有女性梦寐已求的,只有保养好内层肌肤,表面的肌肤才能健康美丽。健康的内层肌肤对美化表面肌肤至关重要。随着冬季的来临,由于温度和湿度的变化,皮肤新陈代谢的速度减慢,使皮肤保留水份的能力降低,因此皮肤变得很干。而新陈代谢减慢,又会导致受伤的皮肤细     

爱的那朵云

一、遗失的手套段小苏:初春的午后,我将满满两抽屉的手套整理出来,洗净,晾晒,那一排排粉红、浅蓝、鹅黄、草绿、雪白的手套吸引了对面楼里那个扎着好多辫子的小女孩,她趴在阳台上,用兴奋的语调问我:姐姐,你的那些漂亮手套为什么只有一只呢,它们的另一半呢?它们的另一半被我落在了夏宇的口袋里。以前,每次让他把手套还给我的时候,     

2009绿色中国年度焦点人物公益奖

总政歌舞团著名青年歌唱演员、国家一级演员蔡国庆获奖感言:这样的时刻在我心中是充满真情和温暖的,因为我始终坚信绿色的中国才是一个更加和谐美丽的中国。我愿意作军中的一棵小白杨,我希望用我的爱心和歌声守护祖国每一片绿色的森林和我们心中绿色的家园。     

十月赞歌

总是在初秋的时候,就充满了对十月的憧憬;总是在金秋的季节,就充满了对十月的渴望。穿过季节的群山,我们以热烈的心跳去拥抱十月旭日的第一缕曙光。越过岁月的河流,我们的心境犹如十月天空第一片柔美耀眼的云裳。     

08香水风尚

香水,这种神奇的化妆品,能带给女人自信和欣喜,它可以愉悦你的心情、平衡你的情绪、表达你的心意、体现你的气质、协调你与周围环境的关系。难怪有人说,一个真正懂得美的女人一定是一个选择和使用香水的高手。的确,香水是造就一个女人整体美的必备单品。本季,各大香水品牌又纷纷推出新品,给爱美的女人更多选择的机会。雅诗兰黛Sensuous系列     

留给后人的不仅是青山

绵延的绿海,茂密的树林,潺潺的溪水,是刚刚离开这个世界的杨善洲留下的最直观的宝贵财富。同时,他还留给我们更多的宝藏。这些宝藏中最重要的,是他为党和人民的事业奋斗终生的精神。从领导的位子上退下来后,     

五月槐花香

喜欢五月的味道,因为五月的阳光下流光溢彩着各色的神奇,空气中也都逸动着各色花蕊的甜香气息。喜欢五月的满眼新绿,因为生物都舒展开自身的躯体,展现出了生命的蓬勃生机,并把生命的活力化为最为眩目灿烂的美丽。五月里,无论是多么柔弱的生命,都会毫不掩饰自身的美质,都会涂抹装点着春光明丽的斑斓和尽情渲染着绿色的柔情欣喜。     

幼小心灵中的自然

人与自然的和谐相处,是生态文明中的重中之重。建设生态文明不是一代人的事情,而是要人类世代相传。那么,在我们的下一代人心目中是如何看待人和自然的关系呢?我们在这里选发了三篇小学生的文章,让读者从中去感受稚嫩心灵对自然界的认识,这是人与自然和谐相处的根基,也是人类未来的希望所在。     

小巷的记忆

在记忆里,家乡的小巷充满着平凡的快乐,给我的童年留下滚烫的记忆。家乡的小巷很窄,小巷两边挤满住户,屋檐相接,错落有致,挤出了中间一条弯弯曲曲的小路,延伸着我的记忆。家乡的小巷很长,铺一路的碎石或石板,那里有我童年时代的嬉笑,有我少年时代的初恋,有我离别时的留恋。     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Comparative performance of four multi-purpose trees associated with four grass species in the humid regions of Southern India

The results of a field trial conducted at the Livestock Research Station, Thiruvazhamkunnu, Kerala to study the compatibility of different components in a silvo-pastoral system revealed that growth and yield of fodder species were significantly influenced by the tree components only after tree canopy formation. The fodder species such as Pennisetum purpureum Schum., Panicum maximum Jacq., Brachiaria ruziziensis Griseb. and Euchlaena mexicana Schrad. grown in association with Casuarina equisetifolia J. R. & G. Forst. and Ailanthus malabarica DC recorded comparatively higher forage yield even after canopy formation. However, forage crops grown in combination with Acacia auriculiformis A. Cunn. ex Benth. and Leucaena leucocephala (Lam.) de Wit. registered relatively lower values for growth and yield. Increased light infiltration into the understorey due to the cladophyllous canopy can be attributed as reason for the higher fodder productivity under Casuarina. Due to the combination of crown size and shape, tree height and spacing the amount of light intercepted by Ailanthus also was very low. Among the four multi-purpose trees used, Acacia recorded the maximum growth rate followed by Casuarina, Ailanthus and Leucaena. Forage productivity of the four species was in the order: Pennisetum purpureum > Panicum maximum > Brachiaria ruziziensis > Euchlaena mexicana. Casuarina with Pennisetum/ Panicm were found to be optimal tree — forage combinations for silvo-pastoral systems.     

Growth, nitrogen fixation and mineral acquisition of Alnus sieboldiana after inoculation of Frankia together with Gigaspora margarita and Pseudomonas putida

The role of tetrapartite associations among Frankia, Gigaspora margarita (an arbuscular mycorrhizal fungus), Pseudomonas putida (rhizobacterium), and Alnus sieboldiana in growth, nitrogen fixation, and mineral acquisition of A. sieboldiana was investigated. Seedlings of A. sieboldiana were inoculated with Frankia isolated from root nodules of alder, followed by inoculation of G. margarita and P. putida, and were grown for 5 months in a greenhouse. The seedlings inoculated with Frankia and G. margarita together produced the highest biomass of shoots and root nodules. Nitrogen-fixation activity, measured by acetylene reduction assay, was observed when Frankia was inoculated. The activity, on a per-nodule gram basis, decreased after G. margarita inoculation, but on a per-plant basis there was no significant difference in the activity among inoculation treatments. The mineral content in the seedlings changed after inoculation with Frankia, but not after inoculation with P. putida and/or G. margarita. The results showed a synergistic interaction among Frankia, the mycorrhizal fungus, and the rhizobacterium on the growth of A. sieboldiana.     

Survival and Growth of Picea abies Regeneration after Shelterwood Removal with Single- and Double-grip Harvester Systems

Three stands in Sweden were followed for 7 yrs to study the survival and growth of Norway spruce [Picea abies (L.) Karst.] regeneration after shelterwood removal with single- and double-grip harvester systems. The height of all seedlings within circular plots was recorded before and after final cutting. The tallest seedling and one randomly selected seedling on each circular plot were permanently marked and their annual height growth was measured each year during the period 1993-1999. No significant differences between single- and double-grip harvester systems were found with respect to their effects on regeneration density, survival or annual height growth. The annual height growth of the individual seedlings after shelterwood removal was significantly correlated with seedling height before shelterwood removal. Significant differences were found in annual height growth between seedlings with high and low vitality. Logging damage did not affect the annual height growth. Several practical conclusions were drawn. First, the choice of harvester system does not affect seedling height growth or survival after shelterwood removal. Secondly, the removal of a 200 m³ shelterwood with 200 stems ha^-1 does not seem to constitute a serious problem for seedling survival and growth. Finally, estimated vitality and seedling height both seem to be fairly good predictors of postrelease survival and growth.     

Ectomycorrhizal inoculation of Douglas-fir transplanted container seedlings with commercially produced inoculum

Commercially produced vegetative inocula of Laccaria laccata and Hebeloma crustuliniforme successfully formed ectomycorrhizae with Douglas-fir transplanted container (plug+1) seedlings. After 4.5 months in containers, 83% and 90%, respectively, of short roots were mycorrhizal. L. laccata- or H. crustuliniforme-inoculated seedlings had significantly more mycorrhizal and total short roots than Pisolithus tinctorius-inoculated (4% mycorrhizal root tips) or uninoculated control seedlings. No significant differences were detected in seedling growth at the end of the container phase.After transplantation and growth in nursery beds for 17 months, mean new short root colonization of all seedlings was 80%. H. crustuliniforme persisted as a dominant mycorrhizal fungus on seedlings initially inoculated with this fungus. L. laccata-inoculated seedlings had 40% of their short roots colonized by L. laccata and another 40% by native fungi Rhizopogon and Thelephora spp. All mycorrhizae of control seedlings and those inoculated with P. tinctorius were formed by fungi native to the nusery beds. A significant fungal treatment effect was detected for shoot height only. Control seedlings were significantly taller than L. laccata-inoculated seedlings after transplanting.This article is part of senior author's thesis in partial fulfillment of the Ph.D. degree in the Department of Forest Science at Oregon State University, Corvallis.     

Insecticidal and repellent activities of medicinal plant extracts against the sweet potato whitefly, Bemisia tabaci (Hom.: Aleyrodidae) and its parasitoid Eretmocerusmundus (Hym.: Aphelinidae)

Toxicity and repellent activities of aqueous extracts of nine medicinal plants were evaluated on different life stages of the sweet potato whitefly, Bemisia tabaci. Tomato plants infested with whiteflies were dipped in 10% (wt/wt) of each plant extract for toxicity evaluation. Repellency was evaluated in a choice experiment with detached tomato leaves. All extracts evaluated were relatively ineffective against the adult stage. Extracts of Ruta chalepensis, Peganum harmala and Alkanna strigosa were effective in reducing the numbers of B. tabaci immatures similar to the reduction observed in the imidacloprid treatment. These three extracts were not detrimental B. tabaci parasitoid, Eretmocerus mundus. In addition, the plant extracts Urtica pilulifera and T. capita were repellent to B. tabaci adults. These results indicate that the extracts from the plants R. chalepensis, P. harmala and A. strigosa could act as a potential source for natural product developed for B. tabaci management.     

Rehabilitation of diseased cacao fields in Peru through shade regulation and timing of biocontrol measures

The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased (moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to 25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol can realise their production potential.' This revised version was published online in June 2006 with corrections to the Cover Date.