酸角生产的现状及其开发意见

酸角为豆科酸豆属植物，原产非洲，引种云南已有７００－８００年历史，适於云南干热河谷地区生长。因种种原因过去没有得到应有的重视和发展，近年来随饮料、食品工业的发展，酸角饮料、酸角酱、浓缩果汁等被相继开发应市，导致资源不足。作者对酸角生产中存在的总理２进行了调查并提出了今后开发利用的意见。     

酸角综合利用的现状及发展趋势

酸角用途广泛,可作果用、医用、加工成饮料或食品、提取罗望子多糖和抗氧化物,以及园林绿化等多种用途,本文综述了近20年来酸角的国内外综合利用现状,指出目前国内外酸角的开发利用多集中在果肉的加工利用,罗望子多糖的提取和应用,并根据酸角利用中存在的问题。对今后开发利用的发展趋势提出了几点建议。     

全国唯一的一株独酸角

在云南省海拔1400m以下的干热河谷区如元江、元谋等县的田边地头。村察周围，酸角树（Tamarindusindica）随处可见。酸角村又名罗望子、酸豆，是苏木科酸豆属的“独生子”，云南、广乐、广西等地常有裁培。1883年，孙中山先生从檀香山带回1株酸角树，亲手植于家乡的庭园中，现胸径已达60多厘米，早年因受台风吹袭．斜靠在围墙上，恰似卧龙正待腾飞。1962年，郭沫若瞻仰孙中山故居时，曾吟出“酸豆一株起卧龙，当年榕树已成空”的佳句。但，不管什么地方产的酸角多以酸味为主，即使有的被叫做“甜酸角”，仍不免有淡淡的酸味。人们吃酸角时…     

云南酸角资源及其水保经济林开发

本文分析了云南省酸角资源状况、酸角适生环境、类型及其综合价值，并对云南省金沙江干热河谷酸角水保经济林的开发提出可供参考的建议。     

酸角营养袋嫁接育苗技术

酸角从品种资源上分为酸型、甜酸型、甜型3个群体品种类型。为了把酸角3个群体品种类型中经济价值较高的甜型、甜酸型优良单株，通过无性繁殖，保留其优良性状，在生产上推广运用，达到早果、丰产、优质栽培的目的，从1997年开始，省农科院热经所在元谋县的一个面积为66.7 hm2的雨养酸角示范园内，开展了对酸角营养袋嫁接育苗的试验研究：以本地适应性较强的酸型酸角做砧木，把从西双版纳、泰国等地引种的实生繁殖甜型、甜酸型优良单株作为嫁接品种，进行嫁接。通过近4a的试验研究，初步总结出一套酸角营养袋嫁接育苗技术，接后砧穗亲和力较…     

云南古树名木

在我省元谋县苴林乡龙山村旁的空隙地中,生长着一棵罕见的酸角巨树。它树高10米、胸围5.1米。冠幅占地竟达0.8亩,看来这棵树的年龄也有二三百年了,而今却还枝叶茂盛,果实累累。酸角是多年生乔木,是南亚热带地区群众最为喜爱的一种多功能水果,其味酸甜可口,能生食,亦能酿制全天然饮料,产地群众多用其浸泡成汁当作酸味调料。     

酸角

酸角Ｅ．Ｗ．Ｍ．Ｖｅｒｈｅｉｊ等１原产地与地理分布酸角（ＴａｍａｒｉｎｄｕｓｉｎｄｉｃａＬ．）的原产地不详，一般认为它原产热带非洲的干旱大草原，很早以前就已引种到亚洲热带地区。当今所有热带国家都有栽种，在印度还有酸角种植园，酸角在东南亚地区具有重要的...     

酸角种子多糖对菠萝常温保鲜效果的研究

<正> 在水果化学保鲜中,筛选天然无毒保鲜剂是一个十分重要的课题;国内外对魔芋多糖进行过一些研究。为此,我们用热带地区盛产的酸角豆种子多糖对菠萝保鲜的效果进行了试验。酸角(Tamarindus indica Linn),又名罗望子,豆科常绿乔木,其荚果的果肉可供鲜食,制作酸味调料和清凉饮料;种子子叶中含多糖65％,主要由葡萄糖、木糖、半乳糖组成。该多糖无毒无味,具凝结和稳定作用,可作冰淇淋等食品添加剂,且具有良好的成膜作用和保水作用。     

干热河谷发展酸角大有可为

干热河谷发展酸角大有可为冷洪万酸角──学名罗望子，系苏木科罗望子属常绿乔木，树高可达１０－２０米，直径６０～８０匡米；真果为荚果，１２月至次年２月成熟，长５～１５厘米，内果皮肥厚肉质可食，味酸或微酸，含有丰富的维生素。蛋日质、糖分等多种人体所需元素；...     

元谋干热河谷雨养型酸角对三种燥红土壤适应性研究

分析了元谋干热河谷旱坡地典型三种燥红土（普通燥红土、黄粉沙质燥红土、变性燥红土）土壤的理化性状在三种土壤上种植的同龄、同品种酸角在同管理水平的条件下，其生长、产量、果实品质表现出明显的差异：普通燥红土质酸角生长量、产量、品质表现最好，黄粉沙质燥红土次之，变性燥红土最差。并通过对三种燥红土质退化程度分析研究，提出土壤侵蚀的退化酸角园整治措施。     

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.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

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.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

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。     

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.