松干蚧的普查方法

“指挥员的正确的部署来源于正确的决心,正确的决心来源于正确的判断,正确的判断来源于周到的和必要的侦察和对于各种侦察材料的联贯起来的思索。”“作几次周密的     

以诗歌和绿色的名义

以怀古的心情怀念远祖的村庄试想用怎样的方式增大心脏的容量完成此生唯美的收藏把一棵树理解为成材的过程是荒唐的任何生长都有自己固执的走向把一朵花想象成爱意的装潢是荒唐的季节的表情产生于深处的独想借用一抷黑土酿制粮食的纯度借用一粒飞沙击打流浪的行程借用一叶秋愁压弯临冬的脊梁草茎与林木的风湿已深入膝踝和每一处骨节疼痛的长夜折磨事物无辜的睡床盘点库存还有多少骄傲的资本参加未来的邀请生态脆弱着已无力承载疯狂的放纵和铺张折下嫩绿的枝条就是折断春天的手指呵拘捕翠鸟的翅膀就是拘捕自由的歌唱呵开垦草原砍伐森林就是砍…     

中国园林发展方向之我见

白雪皑皑的白山黑水,椰林高耸的南海琼崖,西北边疆的天出雪峰,锦秀江南的鱼米之乡,林海起伏的大兴安岭,水波粼粼的五百里滇池,一望无际的内蒙古大草原,四季鲜花的西双版纳;雄伟的泰山,奇险的华山,铁骨冰肌的黄山,秀逸飘然的武夷     

良好的常规是提高幼儿绘画水平的前提

绘画水平的提高离不开良好的常规的建立,良好常规的建立能引发幼儿与周围环境相互作用,进一步促进孩子们的动手能力的发展。在良好常规的建立中孩子们的倾听习惯的养成起着很重要的作用。在孩子们作画习惯和整理工具等方面的培养同样的是需要良好常规的支撑。     

国有林场改革与可持续发展初探

指出了随着气候的异常变化,使得全球变暖的情况加剧,世界提前进入了暖季,基于此,在全人类可能遭遇气候危机的情况下有众多国家领导人联合签署了关于"可持续发展"的理念的倡议书,建议全面发展以可持续理念为核心的环保的能源建设和资源开发。面对"可持续发展"的时代大潮,在我国,一些旧有的、效能低下的、产能落后的事物也即将经历改革发展的大潮进而焕发新面貌,其中就包括我国的一些国有林场。以广东省境内的国有林场的改革为例,探讨了可持续发展的理念对于我国的国有林场改革的意义,以及其能为我国的国有林场的未来发展带来怎样的质的飞跃,并根据广东省的地理特点,结合可持续发展理念的理论要求,提出了国有林场全面改革的相关建议。     

青姿绽放 塞罕踏青

春雷惊醒了塞竿的酣梦,春风轻拂过冬眠的小草,春雨洙浴着广阔的原野。河边的柳树穿上了嫩黄色的外衣,红彤彤的山丹丹也伴着春天的脚步,用封存一冬的热情生动塞罕的颜色。这份来自塞罕的淡雅请柬,轻轻叩开您的心扉;这本大自然朴实的写真．唤起您对塞罕无尽的神往;这无边的旷野、高洁的映山红,又一次在您美丽的假期激情绽放!     

林场的春天

每一个日子都十分富有 那些神秘的小花 铺成林场的封面 抒情诗一样的小鸟 活跃在绿色的林间 这是林场的春天 老一辈林区人的心情开始温暖 青年们谈论着时代的美感 游览林区的学生 在作文中写下脆嫩的新鲜感 这是林场的春天 每一个林区人想象的翅膀 都涂满浪漫的颜色 每一个林区人的胸怀 都掀起了泛绿的波澜     

森林,人类的精灵

大漠肆虐的风一度刮来，深深地刺伤我们的眼睛。林丛稀疏的叶隙间，缕缕阳光，穿越长空，折射出我们齐声高唱着的歌。生命与土地之间，那血与肉的联结，情与爱的牵缠，如一个执拗的少年深情的爱抚，拥抱、喃喃。心与心之间燃灼着熠熠的生命光环。山一样巍峨的英姿，晨露洗濯的灵魂。那不是由虚幻的雾障，浓墨重彩的涂抹，斑澜的线条所组成的彩虹。根与根的交错中凝结的是无声的呼应，枝叉与叶系间组合的是力量的象征。生命中的契机，注定有那么一天，山洪欲来，大漠携着飙尘的飓风而来。你这个人类的精灵，就会挺起高山的头颅，长城的胸怀，…     

年轮的启迪

一裸古老树木的伐根布满密密层层的年轮在军事家的眼里看到等高线、陡坡和山峰在画家的眼里看到水的涟漪,天的云层数学家认定是圆的轨迹金石家硬说是造物主的刀痕儿童看到奇幻的故事老人却说是脸上的皱纹纺织工看到分明的经纬恋人们说是无限深情然而,只有敏感的气象学家看到了每个年代的雨雪风情那窄的年轮因为干旱少雨那宽的年轮是风调雨顺那不宽不窄的年轮是中等年份抑或偏歉偏丰把年度和宽窄数绘入座标一条有趣的曲线陡然而生曲线中可推出变化规律犹如心电图用于医生神秘的年轮—美丽的花环无不是历史的见证年轮的启迪@赵珍~~     

故乡的槐花

每到百花争艳的季节,故乡的槐花就浮现在我的眼前,它那特有的裹着泥土芬芳的气息便会在我记忆的缎带上飘荡…… 在我儿时的记忆里,槐花的生命是短暂而顽强的。当春风染绿荒原野岗的时候,深深植根于故乡黄土地的槐树的枝头上便会爆出无数颗米粒大的芽儿。一     

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.     

泡桐叶片蛋白质多态性及其聚类分析(英文)

根据白花泡桐（Paulownia fargesii）、白花兰考泡桐（P.elongata f. alba）、毛泡 桐（P. tomentosa）、川泡桐（P. fargesii）、山明泡桐（P. lamprophylla）、成都泡桐 (P. albiphloea var chengtuensis)、鄂川泡桐（P. albiphloea）、南方泡桐（P. austra lis）、白花泡桐（P. fortunei）、兰考泡桐（P. elongata）叶片蛋白质单向电泳和双向 电泳结果，可将它们聚类分为白花泡桐组（白花泡桐和白花兰考泡桐）、南方泡桐组（南方 泡桐和成都泡桐）和毛泡桐组（毛泡桐、川泡桐、鄂川泡桐、山明泡桐和兰考泡桐）。该结 果为泡桐属植物的分类提供了参考依据，也为泡桐属植物种确立、杂种鉴定和新品种培育奠 定了基础。     

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.     

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.     

Protein diversity ofPaulownia plant leaves and clusters

Paulownia tomentosa, P. fargesii, P. lamprorhylla, P. albiphloea, P. australis, P. fortunei, P. elongata, P. elongata f. alba andP. albiphloea varchenggtuensis were classified into three groups:P. fortunei group (P. fortunei andP. elongata f. alba);P. australis group (P. australis andP. albiphloea varchenggtuensis) andP. tomentasa group (P. tomentasa, P. fargesii, P. albiprhlaca, P. lamproprhylia andP. elongata) accordance to the results of the single and two-dimensional SDS-PAGE of protein in thePaulownia tree leaves. The result could lay a foundation for classifying the GenusPaulownia plants. Foundation Item: This paper was supported by National Nature Science Foundation of China and Nature Science Foundation of Henan Province. Biography: FAN Guo-qiang (1964-), male, Professor in Institute ofPaulownia Henan Agriculture University. Zhengzhou 450002, P. R. China. Responsible editor: Song Funan     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Litterfall,litter decomposition and the use of mulch of four indigenous tree species in the Atlantic lowlands of Costa Rica

Litterfall, forest-floor litter biomass and nutrients, short-term litter decomposition and the effects of leaf mulches on initial growth of maize were studied for four indigenous tree species with agroforestry potential:Stryphnodendron microstachyum Poepp. et Endl.(S. excelsum), Vochysia ferruginea Mart,Vochysia guatemalensis Donn. Sm. (V. hondurensis) andHyeronima alchorneoides (O), growing in a young experimental plantation in the Atlantic humid lowlands of Costa Rica. Total annual leaf litterfall was higher inV. ferruginea plots, followed byS. microstachyum, V. guatemalensis andH. alchorneoides; all with values comparable to those reported for other tree species grown in agroforestry combinations in humid tropical regions. Forest-floor litter accumulation was highest underV. ferruginea andV. guatemalensis. Both litterfall and forest-floor litter material had similar patterns in nutrient concentrations: N was higher inS. microstachyum, Ca was higher inV. guatemalensis, K was higher inH. alchorneoides; Mg was higher inV. guatemalensis andH. alchorneoides; H. alchorneoides andV. guatemalensis had the highest P.V. ferruginea litter decomposed more slowly, whileS. microstachyum apparently decomposed faster than the other species. The twoVochysia species showed increases in N and P concentration in decomposing litter after seven weeks in the field,H. alchorneoides showed an increase in litter N and a decrease in litter P, andS. microstachyum showed a net decrease in both N and P over the same time period. The patterns found in the litter bag study were confirmed by results obtained in a tethered-leaves experiment.S. microstachyum andV. ferruginea litters lost more weight when mixed in a 11 proportion than either of them alone. Maize seedlings growing in plots mulched withS. microstachyum andH. alchorneoides leaves showed greatest initial growth, confirming patterns found in decomposition and nutrient release studies. The results show that these species could be used in agroforestry combinations with different advantages according to the specific objectives desired, whether these are soil protection, nutrient recycling, or enhancement of the growth of associated crops.     

Biogeochemical impacts of clearfelling and reforestation on blanket-peatland streams: II. major ions and dissolved organic carbon

Streams and drains in blanket-peatland forest in western Ireland were sampled weekly over 5 years, 1996–2000, using continuous, depth-proportional passive sampling. Analysis was for pH, alkalinity by Gran titration, anions by IC, metals by ICP, aluminium speciation by loaded-resin exchange, and dissolved organic carbon (DOC) by absorbance at 320 nm.

Effects of felling are identified graphically from two forest drains whose catchments (both about 1 ha) were clearfelled, and partial clearfelling of one larger catchment (somewhat over 1 km²), in summer 1999. Calcium concentrations and alkalinity were increased in the drain- and streamwater from the felled areas. The pH was increased in drains, while in the larger stream, pH range decreased while the mean increased. Phosphorus increased markedly with clearfell, in the absence of recent fertilising, and also increased with fertilising; these results are reported in an accompanying paper. Ammonium-nitrogen concentrations were increased in the two drains with felling, and temporarily decreased in the larger stream. Nitrate increased in some cases. Potassium and manganese concentrations also increased. Concentrations of DOC and organic monomeric aluminium increased gradually, subject to a continuing strong annual cycle. There were no clearfelling effects on concentrations of solphate, suspended solids or inorganic monomeric aluminium. In the two drains (fully clearfelled), concentrations of sodium, chloride and magnesium, and conductivity, were all reduced after felling. Fertilising effects other than for phosphorus were indistinct.

Effects of the combined clearfell–reforestation treatment were testable statistically, using randomised intervention analysis, between two larger streams (1 km²) as a treatment–control comparison. There were statistically significant positive responses in streamwater concentrations of nitrate, potassium, calcium, DOC and aluminium fractions. The implications for management practice depend on whether the loss of nutrients is sustainable for future crop productivity, and whether critical limits and loads of receiving ecosystems are exceeded.     

Some biological interactions between the parasitoid <Emphasis Type="Italic">Anagyrus pseudococci</Emphasis> (Girault) (Hymenoptera: Encyrtidae) and its host <Emphasis Type="Italic">Planococcus ficus</Emphasis> (Signoret) (Hemiptera: Coccoidea: Pseudococcidae)

The development, longevity, fecundity and life-table parameters of the endoparasitoid Anagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae), 15 d.o. (3rd-instar nymphs) and 21 d.o. (young adult females) of the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) at 28 ± 1°C, 65 ± 10%RH and 16:8h L:D under laboratory conditions. The developmental time of female parasitoids within the host was 17.7 ± 0.39 days in 15 d.o. and 16.65 ± 0.25 days in 21 d.o. hosts; for males, development time was 16.85 ± 0.29 and 15.25 ± 0.09 days, respectively. The average number of offspring per female was 22.35 ± 1.68 in 15 d.o. and 34.8 ± 2.56 in 21 d.o. vine mealybugs. The longevity of female parasitoids was 14.8 ± 0.98 days in 15 d.o. and 15.65 ± 0.92 days in 21 d.o. mealybugs, respectively; for males, longevity was determined as 7.3 ± 0.43 and 6.7 ± 0.54 days, respectively. The mean time of pupation was 7.85 ± 0.003 days in 15 d.o. mealybugs and 8.65 ± 0.003 days in 21 d.o. mealybugs. The aggregate encapsulation rate in the parasitized 15 d.o. mealybugs was 49.73 and 60.36% in 21 d.o. mealybugs. Furthermore, effective encapsulation was 24.82% in 15 d.o. mealybugs and 37.50% in 21 d.o. mealybugs. Population growth rate (r _m) for A. pseudococci was 0.0999 female/female/days in 15 d.o. mealybugs and 0.1269 female/female/days in 21 d.o. mealybugs. The mean population generation time was 23.49 days for parasitoids reared in 15-days-old and 22.39 days when reared in 21 d.o. mealybugs.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.