竹缺爪螨生物学特性及其发生与环境的关系

研究结果表明,竹缺爪螨（ Ａｐｏｎｙｃｈｕｓｃｏｒｐｕｚａｅ Ｒｉｍａｎｄｏ） 营两性或孤雌生殖,孤雌生殖产雄卵;雌螨日产卵１ ～２ 粒,一生平均产卵９－８ 粒;林间自然性比为２－３５∶１ ;该螨以雌成螨和卵滞育,１１ 月中旬入蛰,３ 月上旬出蛰;在一定温度范围内,各螨态发育历期随温度升高而变短,从卵到成螨产卵有效积温为２８０－７６ 日度,发育起始温度为１３－３２ ℃。该螨还可取食苦绿竹（ Ｄｅｎｄｒｏｃａｌａｍ ｕｓｂａｓｉｈｉｒｓｕｔａ） 、长毛米筛竹（ Ｂａｍｂｕｓａ ｐａｃｈｉｎｅｎｓｉｓ） 、半耳箬竹（ Ｚｎｄｒｏｃａｌｍｕｓｌｏｎｇｉａｕｒｔｕｓ） ,并完成其生活史,在麻竹（ Ｄｅｎｄｒｏｃａｌａｍｏｐｓｉｓｌａｔｉｆｌｏｒｕｓ） 、毛金竹（ Ｐｈｙｌｌｏｓｔａｃｈｙｓｎｉｇｒａ） 上不能存活,在苦绿竹上完成１ 代需１８－４ ｄ;降雨的冲刷及浸水对幼、若、成螨存活影响较大,短期浸水对卵孵化影响不大,浸水１ ｄ 后卵孵化率降至３０－６５ ％ 。利用灰色关联度（Ｔｈｅ Ｇｒａｙ Ｓｅｑｕｅｎｃｅ） 方法分析湿度、气温、降雨量、天敌４ 个因子对该螨种群消长的影响,结果表明,４ 个因子对幼、若、成螨数量消长的关联序为湿度＞ 降雨量＞ 天敌     

生态因子对针叶小爪螨的影响

本文研究了温度，光照，降雨，板栗品种等生态因子对针叶小爪螨ｏｌｉｇｏｎｙｃｈｕｓｕｎｕｎｇｕｉｓ（Ｊａｃｏｂｉ）生长发育和种群消长的影响，明确了不同温度下的发育历期，死亡率，寿命，单雌产卵量，光照时间对滞育的作用以及降雨对螨口密度的影响等内容，研究了不同板栗品种对该螨的抗性，并调查了针叶小瓜螨的主要天敌种类。     

生态因子对针叶小爪螨的影响

本文研究了温度、光照、降雨、板栗品种等生态因子对针叶小爪螨ｏｌｉｇｏｎｙｃｈｕｓｕｎｕｎｇｕｉｓ（Ｊａｃｏｂｉ）生长发育和种群消长的影响，明确了不同温度下的发育历期、死亡率、寿命、单雌产卵量，光照时间对滞育的作用以及降雨对螨口密度的影响等内容，研究了不同板栗品种对该螨的抗性，并调查了针叶小爪螨的主要天敌种类。     

枣树红蜘蛛在自然变温下有效积温的研究

该文对枣粮间作地中枣树红蜘蛛──截形叶螨的卵、幼螨、前若螨、后若螨４个虫期在自然变温下的有效积温进行了研究，结果表明，卵的发育起点温度１４．８±１．５６℃，有效积温为３９．３５６３日度；幼螨发育起点温度为１１．５±２．７３℃，有效积温为２７．８４日度；前若螨发育起点温度为１１．０±２．０８９℃，有效积温为４２．１３４７日度；后若螨发育起点温度为１２．８±１．８７℃，有效积温为３７．１日度；世代发育起点温度为１１．２±１．８３６℃，有效积温为１１６．２４４６日度。年发生１３代。     

针叶小爪螨综合防治技术策略探讨

针叶小爪螨综合防治技术策略探讨孙绪艮，周成刚，刘玉美，张小娣（山东农业大学林学系）针叶小爪螨Ｏｌｉｇｏｎｙｃｈｕｓｕｎｕｎｇｕｉｓ（Ｊａｃｏｂｉ）在中国北方地区是危害板栗、麻栎等壳斗科植物的重要害螨。据调查，山东烟台、潍坊、临沂、日照、泰安等地市的板...     

截形叶螨为害枣树的初步观察

截形叶螨ＴｅｔｒａｎｙｃｈｕｓｔｒｕｎｃａｔｕｓＥｈａｒａ，又称枣树红蜘蛛，是为害枣树的一大害螨。日均气温在２５．６℃时，其卵期为４天，幼、若螨期为６－７天，完成一个世代需１１－１２天（包括１天产卵前期）．该螨上树为害时间的早晚与当年４－５月份的气温及降水有关，若气温高降水少，前期出口繁殖积累就多，则上树为害就早；反之则迟。防治上一般在７月１０日前后施第一次药，隔５－１０天再施第二次药，即可收到良好效果．     

截形叶螨为害枣树的初步观察

截形叶螨Ｔｅｔｒａｎｙｃｈｕｓ ｔｒｕｎｃａｔｕｓ Ｅｈａｒａ，又称枣树红蜘蛛，是为害枣树的一大害螨。日均气温在２５．６℃时，其卵期为４天，幼、若螨期为６－７天，完成一个世代需１１－１２天（包括１天产卵前期）。该螨上树为害时间的早晚与当年４－５月份的气温及降不有关，若气温高降水少，前期虫口繁殖积累就多，则上树为害就早；反之则迟。防治上一般在７月１０日前后施第平欠药，隔５－１０天再施第二次药，即可收     

宁夏地区光肩星天牛天敌种类调查初报

在宁夏地区光肩星天牛Ａｎｏｐｌｏｐｈｏｒａ ｇｌａｂｒｉｐｅｎｎｉｓ （Ｍｏｔｓｃｈ．）的天敌主要有：花绒穴甲Ｄａｓｔａｒｃｕｓ ｈｅｌｏｐｈｏｒｏｉｄｅｓ（Ｆａｉｒｍａｉｒｅ）、赤腹茧蜂Ｉｐｈｉａｕｌａｘ ｉｍｐｏｓｔｅｒ（Ｓｃｏｐｏｌｉ）、草地铺道蚁Ｔｅｔｒａｍｏｒｉｕｍ ｃａｅｓｐｉｔｕｍ （Ｌ．）、膜毛绥螨Ｌａｓｉｏｓｅｉｕｓ ｏｍｅｔｅｓ Ｂｅｒｌｅｓｅ、毛绥螨Ｌ．ｓｐ．，蠹蛾肛厉螨Ｄｅ     

宁夏地区光肩星天牛天敌种类调查初报

在宁夏地区光肩星天牛Ａｎｏｐｌｏｐｈｏｒａｇｌａｂｒｉｐｅｎｎｉｓ（Ｍｏｔｓｃｈ．）的天敌主要有：花绒穴甲ＤａｓｔａｒｃｕｓｈｅｌｏｐｈＯｒｏｉｄｅｓ（Ｆａｉｒｍａｉｒｅ）、赤腹茧蜂Ｉｐｈｉａｕｌａｘｉｍｐｏｓｔｅｒ（Ｓｃｏｐｏｌｉ）、草地铺道蚁Ｔｅｔｒａｍｏｒｉｕｍｃａｅｓｐｉｔｕｍ（Ｌ．）、膜毛绥螨ＬａｓｉｏｓｅｉｕｓｏｍｅｔｅｓＢｅｒｌｅｓｅ、毛绥螨Ｌ．ｓｐ．、蛾肛厉螨ＰｒｏｃｔｏｌａｅｌａｐｓｃｏｓｓｉＭｕｌｅｒ、枝厉螨Ｄｅｎｄｒｏｌａｅｌａｐｓｓｐ．     

温度和光照对松褐天牛生长的影响

1999－2000年在浙江省杭州市研究了温度和光照对松褐天牛幼虫生长的影响，结果为：在正常情况下，松褐天牛1代，以4龄幼虫越冬，在光照16h(6-22时），适当升温（12－15℃）时部份幼虫能够化蛹或者羽化成虫，短日照8h(6-16时）抑制幼虫生长，或者产生滞育幼虫，逆反自然界正常日照能诱发幼虫滞育，临界光周期虫态尚待继续观察，8月中下旬产的卵，孵化的幼虫以3龄幼虫在树皮越冬，不能蛀入木质部。     

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.     

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.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.