浙江诸暨白塔湖国家湿地公园两栖爬行动物多样性研究

2017-2018年每年的4-8月,在浙江诸暨白塔湖国家湿地公园开展了两栖爬行动物资源调查,并从物种组成、地理区系、保护等级等方面进行了分析。结果表明,湿地公园共有两栖爬行动物3目10科,其中,两栖动物有1目4科8属10种,爬行动物有2目6科13属13种;湿地公园内两栖爬行动物在动物区系成分上具有明显的东洋界特征;存在较多的单属种;爬行动物多性样指数略高于两栖动物。在生物多样性保护价值方面,湿地公园两栖爬行动物体现出典型的平原水网区域的资源特点,并且记录有国家重点保护野生动物1种,浙江省重点保护野生动物2种,中国生物多样性红色名录近危以上物种8种,IUCN濒危等级近危以上物种2种。调查表明湿地公园主要的生态问题是栖息地破碎化和外来物种入侵,为此,提出了妥善处理公园内集体土地;开展野生动物栖息地改造;防控外来物种入侵;开展两栖爬行动物长期监测的建议。     

渭南市湿地公园建设与保护存在的问题初探

陕西渭南市湿地资源丰富,目前有国家湿地公园1个,试点7个,总面积10 715hm2。本文对渭南湿地公园建设与保护中存在的问题进行了分析研究,提出了相应的对策建议,对渭南湿地公园建设与保护有一定借鉴作用。     

安阳城市湿地资源保护网络建设初探

湿地被称为"地球之肾",是一种重要的自然资源。安阳市共有湿地面积10281.21 hm2,分6种类型。湿地植物有维管植物168种,分属62科、130属;重点湿地鸟类分属7目、13科、34种。文中总结安阳湿地资源保护现状及当前湿地保护中存在的主要问题,提出湿地资源保护和利用建议;从安阳实际出发,根据保护优先、合理利用,点面结合、突出重点,就地保护、分区分类,科学利用、持续发展的原则,进行安阳市湿地保护规划;以洹河湿地公园和野生动物栖息地建设为例,实际探索建立城市湿地保护网络之路。     

安阳漳河峡谷国家湿地公园生物多样性保护对策

对安阳漳河峡谷国家湿地公园生物多样性进行了物种现状调查。查清了现有植物资源70科181属413种,其中国家Ⅱ级重点保护植物3种;动物资源31目76科170属238种,其中国家Ⅰ级保护动物有2种、国家Ⅱ级保护动物有24种。对湿地生态系统进行了客观评价,分析了湿地生物多样性保护存在面临的主要问题,有针对性地提出了保护对策。     

台州市湿地资源现状及保护管理对策探讨

台州市现有2 hm2以上湿地32.2万hm2,分为近海及海岸湿地、河流湿地、沼泽湿地和人工湿地4大类、18个湿地类型;共有湿地维管束植物134科438属722种,水生动物有鱼类2纲14目53科428种、甲壳类动物96种、软体动物4目7科11种,陆生动物有两栖动物2目7科20种、爬行类2目3科22种、鸟类10目21科120种、兽类4目6科17种;湿地保护管理与利用存在的主要问题是:湿地水质污染、过度围垦、生物资源过度利用、生物入侵危害严重。提出了完善湿地保护的地方规范制度,政府实行对重要湿地的完全控制,加强湿地保护区(小区)、湿地公园的规划建设,建立健全湿地环境监测网络等对策。     

浙江德清下渚湖国家湿地公园动植物资源调查研究

2018年8月—2019年6月,对浙江德清下渚湖国家湿地公园开展了动植物资源调查研究。结果表明,湿地公园内有维管束植物126科354属535种,以菊科Asteraceae、禾本科Poaceae、豆科Leguminosae所占种类最多,有3种国家Ⅰ级保护植物、9种国家Ⅱ级保护植物,也有27种入侵植物;植被类型有6个植被型组10个植被型73个群系。大型水生无脊椎动物有2门3纲4目10科25种,以蚌科Unionidae所占种类最多;脊椎动物有5目104科242种,其中,鱼类有17科51种,以鲤科占优势;两栖类有6科14种,以蛙科Ranidae类群最多;爬行类有8科19种,以游蛇科Colubridae的种类最多;鸟类有49科137种,以雀形目Passeriformes的种类最多;哺乳类有14科21种,以鼬科Mustelidae种类最多;属于国家一级保护野生动物有1种,为朱鹮Nipponia nippon,国家二级保护野生动物7种,并有8种外来入侵动物。该湿地公园物种丰富、保护物种较多,但存在生境破坏、外来物种入侵、偷捕现象严重等人为干扰的问题,提出了退塘还湖、推广生态养殖模式、禁止滥捕、截污纳管等动植物保护的建议。     

河南省湿地现状与保护对策

根据河南省第二次湿地资源调查统计,河南省湿地面积627946.14 hm2,分为4大类8个类型;有湿地维管束植物850种,隶属134科470属;有湿地脊椎动物498种,隶属于5纲35目92科。分析了河南省湿地及湿地建设中存在的主要问题,针对性提出了保护和管理建议。     

湖南永顺猛洞河国家湿地公园植物资源特点研究

通过野外调查、标本采集与鉴定和查阅文献,对湖南永顺猛洞河国家湿地公园植物资源进行了统计和分析。结果表明:湖南永顺猛洞河国家湿地公园植物多样性高,珍稀特有植物丰富,有维管束植物149科472属710种,其中湿地植物207种、石灰岩特有种52种、中国特有种127种、国家重点保护野生植物7种;种子植物区系具有丰富性、古老性和过渡性的特点;森林植被以人工植被和石灰岩生境次生植被为主,湿地植被划分为4个植被型组、10个植被型、40个群系。并分析了湿地公园植物资源特点形成的原因,以期为湿地公园植物资源保护提供参考依据。     

四川阿坝多美林卡国家湿地公园鸟类多样性研究

多美林卡国家湿地公园位于四川、青海和甘肃三省交界处,为永久性河流湿地公园。为系统掌握多美林卡湿地公园的鸟类资源情况,2017年至2019年,采用样线法与样点法对湿地公园进行9次调查,共记录到鸟类176种,隶属于17目44科116属。湿地公园以留鸟（90种）和夏候鸟（43种）为主,共计133种,占公园鸟类种数的75.57%;古北界鸟类占优势,共计111种,占公园种数的63.07%。湿地公园有各级保护鸟类44种,其中国家Ⅰ级11种,国家Ⅱ级重点保护鸟类25种,四川省重点保护鸟类8种。利用G-F指数对湿地公园鸟类多样性进行评估,结果显示,湿地公园鸟类在科属水平上具有较高的物种多样性。此外,湿地公园内不同生境鸟类物种多样性和群落构成表现出较大差异性,但也存在一定的相似性。本研究为多美林卡国家湿地公园鸟类保护和后期管理工作提供了一定科学依据。     

云南省丽江市湿地资源现状与保护管理对策

利用3S技术与实地调查相结合的方法,查清云南省丽江市的湿地资源现状。该市湿地资源丰富,共有4个湿地类,10个湿地型,湿地总面积36211.62 hm2;湿地植物共有120科800多种,有7个植被类型,68个群系;共有鸟类66种、鱼类25种、两栖类6种、爬行类3种、兽类14种。针对湿地资源特点与湿地保护管理存在的问题,提出了完善管理机构、加大执法力度等管理对策。     

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.     

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.     

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.     

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。     

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.