荆楚古树全国最多

从湖北省绿化办获悉,大型画册《湖北古树名木》由省绿化委员会、省林业厅正式编辑出版,湖北省国家一级古树名木尽在其中展现。据全省林业系统统计,湖北省有国家一级古树2093株（其中名木10株）、二级5932株,三级777988株,总数786013株,经与各省市区比较,数量居全国第一。一级古树中,树龄千年以上的219株,其中,2000年以上的5株。湖北省古树名木以群生为主,有古树群478群、752000株,占总数95．67％。主要分布在神农架林区和十堰市,分别占古树群83．52％和14．30％。散生的有34013株,主要分布在黄冈市和恩施州。目前,湖北省各地对所有古树名木进行挂牌保护,对500年以上的古树安装避雷针和围栏并专人管护。     

寿宁古樟奇

正福建省寿宁县位于闽浙交界处,由于地处偏僻山区,当地群众民风古朴,不仅热心保护古树名木,甚至有敬古树为神的传统。据调查统计,寿宁县目前已发现并挂牌保护的古树名木共有1066株,其中散生古树1047株,古树群5处,19株。其中一级保护有32株,二级保护有112株,三级保护有922株。在这众多的古树中,尤以芹洋乡阜莽村的古樟树和武曲镇大韩村的"樟抱榕"最为神奇。     

永顺县古树资源调查与评价

在对湖南省永顺县现有古树资源及其特征调查的基础上进行了综合分析和评价,结论是：现保存有古树共3408株,其中三级古树3052株,占89．6％;二级古树286株,占8．4％;一级古树70株,占2．1％;现有古树分属38科、70属、106种,其中国家级保护珍稀树种15科、18属、20种。古树中珍稀保护树种现生长较好的有黄心夜合（珍稀树种）古树32株,其中有树龄超过1000年的古树3株;珙桐古树（Ⅰ级保护植物）42株,其中有树龄在500年以上的古树1株;青钱柳古树（省级保护植物）7株,大叶榉古树（Ⅱ级保护植物）7株,青檀古树（Ⅲ级保护植物）6株;黄杉（国家Ⅱ级保护树种）古树群落2处,共有古树426株。古树资源分布广泛,且多为零星分布,少量以小片状或群落形式分布;古树主要分布在海拔300—600m的地段,其中大部分生长良好;古树资源开发利用潜力大,但保护现状不容乐观。     

山西古树立地环境调查与分析

一、调查背景据调查统计,山西省古树名木有37390株,其中散生的15029株,包括一级古树（树龄500年以上）4406株,二级古树（树龄300年至499年）4406株,三级古树（树龄100年至299年）6217株。古树群74处,共计22361株,其中一、二级古树中有65%以上古树出现不同程度哀弱,     

深圳市特区内2004年度古树现状调查报告

2004年对深圳市特区内4个区的古树进行复查，结果显示1998年在册的414株古树，只余328株；因自然死亡、建房被伐及未找到的古树数量增加到86株，占总数的21．25％；新增补遗或近年来新种植的古树60株，现古树总计387株。针对古树保护存在的问题，提出相应的解决办法和建议。     

西安城市及郊野绿化树种的调查研究

1979年10－11月，在西安市区和郊区以及临潼骊山，华阴华山等进行了集体或分组调查，市区调查树木共3，402株，其中针叶乔木298株，8．8％，常绿阔叶乔木157株，占1．6％，落叶乔木1，795株，占52．8％，常绿灌木203株，占6．0％，落叶灌木760株，占22．3％；藤木189株，占5．5％，在西安市，共调查园林树木275种（变种，变型在内），均按统一表格详细记载，在市区及郊野共记载百年以上的古树74株，其中最老的是一株2，000年生汉槐，对西安市区及郊野调查结果进行了分析，并提出关于西安市基调树种和各类型绿地骨干树种的建议。     

密云区部分古树健康评价

2019年度调查密云区古树117株,其中一级古树65株,占55.56%,二级古树52株,占44.44%。共涉及14个树种,分别是国槐、侧柏、油松、银杏、蒙古栎、桧柏、桑树、酸枣、流苏、卫矛、洋槐、元宝枫、榆树、梧桐。其中国槐57株,占总数的48.72%;其次为侧柏,有30株,占总数的25.64%;油松有11株,占总数的9.40%;银杏有6株,占总数的5.13%;蒙古栎、桧柏和榆树各2株,各占总数的1.71%;桑树、酸枣、卫矛、梧桐、洋槐、元宝枫、流苏各一株。在调查的古树中,"生长良好"古树108株,占总数的92.31%;"生长衰弱"古树8株,占总数的6.84%;"生长濒危"古树1株,占总数的0.85%;无"生长死亡"古树;所调查古树生长势整体趋势为良好。古树生长环境评估中,"生长环境良好"的有60株,占总数的51.28%;"生长环境差"的有57株,占总数的48.72%。评估为"生长环境差"的古树中,一级古树为33株,占总数的57.89%;二级古树为24株,占总数的42.11%。在这些古树中,国槐数量最多,有35株,占总数61.40%。     

广东省乡村古树资源分析及保护对策探讨

古树承载着乡愁，是美丽乡村的独特资源。广东省乡村古树资源丰富，数量占全省古树的87.22%。对广东省乡村古树的种类组成和分布特征进行研究分析，结果表明：广东省乡村古树具有数量众多、种类集中、分布不均等特点，共有70 101株，隶属于82科256属517种，各个树种之间的数量分布存在明显差异，排名前4的树种分别是榕树 Ficus microcarpa、荔枝 Litchi chinensis、樟 Cinnamomum camphora和龙眼 Dimocarpuslongan，共占43.54%；乡村古树树龄分布不均，其中三级古树占92.68%，多为荔枝、龙眼等经济树种；各地级市乡村古树的数量分布存在明显差异；在各个地级市中正常株、衰弱株、濒危株的占比存在明显差异；乡村古树权属主要为集体所有，分布特点表现为文化树种和景观树种主要为散生，经济树种主要为群生。大部分古树的管理缺乏有效的保护措施，可以利用新技术和创新古树管理模式来进一步加强古树名木保护工作。     

丽水市古树名木资源数量和种群特点

从古树名木资源数量和种群特点、生长状况及保护级别等方面对丽水市的古树名木资源进行了研究分析,结果表明:全市现有古树名木40222株,其中一级保护古树880株,占总株数的2.19%;古树群968片23233株,散生分布16989株。平均树高为18.9m,平均胸径为82cm,平均冠幅为10.45m。国家重点保护植物21种7868株,其中国家Ⅰ级保护植物5种2870株,国家Ⅱ级保护植物16种4998株。     

句容宝华山古树名木资源调查

对宝华山古树名木进行了资源调查，发现宝华山古树名木现存28种142株，其中百年以上古树占80％；40cm以上胸径古树名木占71％，15m以上树高古树名木占51％。     

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.