松茸资源限制因子分析

分析了松茸[Tricholoma matsutake(S.Ito.et Imai)Sing.]的分类地位、地理分布和生态环境及其影响,以及影响松茸资源量的生态环境主要有立地条件和气候因子。立地条件包括森林植被、林地土壤和落叶腐殖层,气候因子主要为温度和湿度。分析表明:森林的破坏、气候的干旱以及无序采集的是松茸资源量减少的主要原因,并为松茸资源有效保护和持续利用提供了合理建议。     

保护松茸生态环境促进松茸可持续发展——关于恢复与发展云南松茸的探讨

针对云南省松茸产量连年锐减的严重现实 ,通过对松茸产区及市场的深入了解 ,结合在林间试验地的研究和观测调查 ,提出一系列促进松茸可持续发展的途径。禁止采收和收购占松茸总量约36 .4 %的未成熟幼茸 ,可使云南松茸在现有基础上增产 1.96倍 ;在保持现有松茸生态环境条件下 ,采用科学的采收方法 ,实施一系列有关的科学技术措施 ,在 2 7hm2 范围内松茸产量连年成倍增加 ;在 1hm2试验林范围内 ,松茸个数增加 4 5.2 8% ,产量增加 4 8% ,而有关鸟害等损失则降低 ,森林生态环境得到改善 ,土壤营养条件也不同程度得到改善。因此 ,恢复和保护松茸生态环境并配合适当的技术措施与科学的采集方法 ,更适合当前云南松茸的发展以及经济效益的进一步提高。     

赤松茸资源的开发与经营利用的探讨

赤松茸是生长在赤松林树根部,与树根共生的一种野生食用菌,俗称松茸、松口蘑针松茸,属担子菌亚门层菌纲无隔担子菌亚纲伞菌目口蘑科口蘑属的一个种。松茸的特点是子实体寄生在松树根上,和周围的腐殖层形成菌丝网。松茸菌丝一般在枯枝落叶层下面3—5厘米深处土壤中活动,并进入松树的细根中与之共生形成外生菌根。     

正红菇的生长与生态环境的关系

通过对正红菇生态环境各因子调查观察，为人工模拟生态环境、引种栽培野生红菇提供依据。历时４年的调查研究表明：正红菇是一种外生共生菌；在相对稳定的生态条件下（平均温度２５－２７℃，湿度８０％－１００％，降雨量（土壤含水量）达４０％以上），正红菇发生，降雨量为其主导因子；正红菇年发生２次，在夏秋季节高温、闷热阵雨之后为发生盛期；发生地海拔不限，以山的中下部为多，林间郁闭度０．８左右，土壤ｐＨ值５．６－７．０之间；其共生树种以壳斗科为主。     

关于松茸主要生态因子的调查报告：土壤与小气候

1 试验地本次调查的试验地及其概况与已报导的赤松生长与植被》中的“试验地”相同。2 调查方法2.1 松茸发生林的土壤1977年8月7日,在筒江试验地分别对尾根筋附近的松茸发生地、谷筋附近的松未发生地以及3号样地菌落内外的土壤剖面     

西藏林芝松茸品质地理分异研究

以西藏林芝地区3个县11个样点采集的野生鲜松茸为材料,对外观、含水率、粗多糖、粗蛋白、游离氨基酸、全量铁、全量锌等进行测定,并采用欧氏聚类系统法对11个不同的样品进行了聚类分析,从数量分类上系统探究林芝松茸资源。结果表明:供试的11个样品用聚类分析法可分为3个品质群,以A县的松茸各营养成分综合较高。整个林芝地区的松茸与内地松茸相比则显得个体较小,粗多糖、粗蛋白和锌含量均偏低,而粗脂肪和铁的含量偏高。     

野生菌成为南华县林业特色大产业

南华县地处滇中腹地,广阔茂密的森林、肥沃的土壤、天然的立体气候和独特的地形、地貌为野生菌生长提供了非常适宜的环境。在全县248万亩森林中,适宜生长野生食用菌的林地多达170多万亩,特别是松茸,在10个乡镇61个村委会都适宜生长,分布面积达70多万亩。全县共有各类野生菌2纲9目26科200余种,占全国     

鄂南地木耳的资源分布和生态调查研究初报

地木耳在鄂南各地均有分布,一年四季均可发生。发生地土壤类型、质地差别较大,但均在其表面含较多的石砾,酸碱度以中性到酸性为主;植被中无高大植物,通风状况良好,阳光充足,发生地潮湿但不渍水,且含丰富的有机质。     

皮毛硝染行业周边农田土壤理化特征及其质量评价

为探明皮毛硝染对周边农田土壤质量的影响,以衡水市枣强县大营镇为研究区域,选取土壤容重、含水率、pH值、有机质,速效氮、速效磷、速效钾、全盐量等理化指标,运用土壤综合指数法对其土壤质量进行了评价。结果表明:大营镇农田土壤容重在1.13～1.48 g/cm~3之间,平均值为1.35 g/cm~3,土壤容重较大;土壤含水量在7.39%～21.73%之间,平均含量为16.13%,土壤含水量处于适宜程度;土壤有机质在4.84～18.91 g/kg之间,平均含量为12.87 g/kg;土壤速效氮在22.56～42.75 mg/kg之间,平均含量为31.71 mg/kg;土壤速效磷在5.90～34.59 mg/kg之间,平均含量为18.28 mg/kg;土壤速效钾在15.11～34.57 mg/kg之间,平均含量为24.38 mg/kg,土壤中有机质、速效氮、速效磷、速效钾的含量都较低。土壤含盐量在0.77～3.38g/kg之间,平均含量为1.91 g/kg,土壤大部分处于轻度盐化。土壤质量综合指数平均值为0.40,土壤质量较差。     

云南首个“松茸基地村”挂牌记

5月25日，国家林业局科技司、濒管办和省林业厅的领导一行，驱车行驶上百里山路，风尘仆仆来到云南省富民县罗免乡石板沟村，为云南省首个“松茸基地村”挂牌。石板沟村是富民县的松茸主产区之一。全村有730多公顷森林，其中有130多公顷产松茸。松茸是森林中有很高经济价值和食用价值的珍稀野生食用菌。20年前，松茸进入日本市场后身价倍增，成为一种创汇价值较高的商品。从20世纪90年代起，石板沟村的村民就开始采集松茸出售。1995年，全村共采松茸8吨左右，产值达数十万元，成为该村历史上松茸产量、产值最高的一年。可是，近几年来，由于…     

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.     

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.     

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.     

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.     

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。