基于生态价值的玉田县适生植物资源实地调查与评价

为探索玉田县适生植物资源,进行实地调查,立足于植物资源的生态价值,运用生态服务价值评价与当量因子法研究不同区域的适生植物。结果表明,玉田县北部褐土丘陵地带应多种植榆树、黄栌、油松等植物;中部平原草甸地带应种植紫穗槐、栾树与侧柏等,植物与园林观赏植物交叉种植;南部脱沼泽化潮土区域应多种植油松、栾树、臭椿等植物,补充种植牡荆等观赏植物。     

新疆额尔齐斯河流域杨属植物种间关系的SSR分析

[目的]为探讨额河杨和银灰杨天然杂种的起源机制,[方法]应用18对SSR标记,从分子水平上对新疆额尔齐斯河流域杨属植物的种间关系进行分析研究。[结果]表明:(1)SSR系统发育树将整个流域天然杨属植物分为两大类群,即黑杨派和青杨派为一类,白杨派为一类;(2)白杨派派内系统聚类图显示,银白杨、欧洲山杨、银灰杨三个树种均有较大的遗传分化,特别是杂种银灰杨似乎更大;(3)黑杨派和青杨派的UPGMA分类图显示,青杨派和黑杨派分属于2个分支,其中,青杨派内部分化相对简单,分为2支,均为典型的苦杨;黑杨派内部的分化较为复杂,可分为4类,包括典型的欧洲黑杨、额河杨和回交子代。[结论]杂种额河杨具有更多的欧洲黑杨的遗传成分,因此,将额河杨放到黑杨派是正确的。     

动态经济评价模块原理及其在林分经营模型中的应用*

通过动态经济评价模块，将成本构成要素分解成材料消耗，用工消耗和资金换算单位乘子等基本元素，而用以基本元素以自变量的函数描述成本及收入核算项目，借助模块内专门设计的解码过程，通过外部文件，修改成本构成要素的分解层次和描述单位，重新设计成本核算项目的描述函数，实现了经济评价模块同林分生长模型间的柔性结构匹配。压缩数据向量及其相应算法的引入，不仅减少了内存空间的占用量，而且提高了经济评价模块的运行速度，     

A Comparison of the Utility and Agronomic Traits of Indigenous and Exotic Trees in the Mount Kenya Region

On-farm indigenous (Cordia africana) and exotic (Grevillea robusta) tree species were compared in terms of the quality of their utility and their agronomic traits in the Meru Central district of Kenya. These two species are the most common indigenous and exotic trees, respectively, among the recorded 117 trees on farms. Interviews with farmers and collected documents on tree felling and planting showed that farmers considered C. africana to be more useful than G. robusta. However, farmers wanted to plant more G. robusta than C. africana because the easily established and fast growing G. robusta has a higher short-term contribution to the household economy. The advantages of C. africana, however, should be redefined in terms of its long-term contribution to farmers; C. africana contributes to farming more effectively than does G. robusta. The lower growth performance and relative difficulty in the establishment of C. africana can be compensated for by its higher timber quality and coppicing ability.     

Contrasting rooting patterns of some arid-zone fruit tree species from Botswana – I. Fine root distribution

To assess the possible degree of root competition from fruit trees which could potentially be used in agroforestry systems, fine root density of fruit trees Strychnos cocculoides Bak., Strychnos spinosa Lam. (Loganiaceae) and Vangueria infausta Burch. (Rubiaceae), as well as from the shrubby species, Grewia flava DC. (Tiliaceae) was investigated. Vangueria infausta had the highest fine root densities in both vertical and horizontal extensions. In Vangueria infausta fine root density decreased with increasing soil depth. For the other species in the 80 cm soil profile investigated, no significant changes in fine root density with soil depth were found. For Strychnos cocculoides almost no fine roots were detected in the upper soil horizon (0–20 cm). Using fine root surface area densities, exploration and exploitation indices were calculated. Vangueria infausta had the highest value of the exploration index compared to the other species. For use in agroforestry systems Vangueria infausta was estimated to be the most competitive of the investigated species, whereas Strychnos cocculoides seems to be the less competitive. Strychnos cocculoides has additionally spatial arrangements of fine roots favourable for agroforestry, slowly increasing with depth and additionally low concentrations in upper soil layers.     

Differences in the ultrastructure of their large warts allow white cypress pine (<Emphasis Type="Italic">Callitris glaucophylla</Emphasis>) to be distinguished from black cypress pine (<Emphasis Type="Italic">C. endlicheri</Emphasis>)

White cypress pine (Callitris glaucophylla) wood is durable enough to be used outdoors, but occasionally there are reports of its premature failure in ground contact, which may be due to its substitution by the less durable species, black cypress pine (C. endlicheri). It has been difficult to prove this, however, because the woods of both species are very similar in structure and cannot be separated using conventional anatomical features. This study examined whether differences in the size and morphology of warts on tracheid walls in the two species could be used to identify them. There were significant differences in the height, width and shape of warts in the two species, but there was considerable overlap in the distribution of these parameters between specimens. Warts in C. endlicheri were more likely to be bent-over near their tops than those in C. glaucophylla, and the angle bending of warts was greater in C. endlicheri. Quantification of these parameters produced complete separation of multiple specimens of the two species, and could potentially be used to help determine whether premature failure of C. glaucophylla heartwood in ground contact is the result of its substitution by C. endlicheri. More generally it can be concluded that the morphology of large warts may have taxonomic value in identifying coniferous wood species beyond the generic level.     

In vitro effects of four ectomycorrhizal fungi, Boletus edulis, Rhizopogon roseolus, Laccaria laccata and Lactarius deliciosus on Fusarium damping off in Pinus nigra seedlings

Species of Fusarium cause damping off of forest seedlings resulting in considerable losses and oftentimes fungicides are used to control the disease. Such chemicals may be detrimental to the environment. Protection of forest seedlings against this disease must be focused on integrated management for in which biological control is one of the most important tools. Mycorrhizal fungi may provide protection against pathogen invasion of seedlings. In this study, the interactions between the mycorrhizal fungi Boletus edulis, Rhizopogon roseolus, Laccaria laccata and Lactarius deliciosus and damping off pathogens (Fusarium oxysporum and F. moniliforme) were investigated in vitro and mechanisms involved in the protection of damping off in P. nigra seedlings are also discussed. The effect of filtrates from mycorrhizal species on spore germination of F. oxysporum varied throughout the tests. At the end of the assay, the inhibitory effect only could be observed in the L.␣deliciosus treatment. None of the filtrates reduced spore germination in F. moniliforme. Finally, three of the four mycorrhizal species grown for 2 months in the substrate, L. laccata, L.␣deliciosus and B. edulis, increased the survival of Fusarium inoculated P.␣nigra seedlings.     

Fungi dangerous at Pinus contorta with special reference to pathogens from North Europe

Examples are given of North American fungi potentially dangerous to Pinus contorta plantations in northern Europe. The pathogenicity of North European fungi is discussed. P. contorta was found to be immune or nearly immune to all European rust fungi, more resistant than P. sylvestris to Phacidium infestans and Lophodermium pinastri, but less resistant to Crumenulopsis sororia and Discella strobilina. For other fungi no such clearcut conclusions could be drawn.     

Effects of forest structure and microhabitat on the distribution and flowering of a rare understory plant, Actaea elata

Knowing which environmental characteristics constrain forest understory species’ distribution and reproduction can inform conservation decisions about habitat management and locations for reintroduction efforts. Differential plant performance is common in varying environmental conditions, such as levels of canopy closure. Actaea elata (tall bugbane) is a rare, perennial, forest understory herb found from Oregon to British Columbia. Populations throughout this species’ range commonly occur in managed forests. We assessed the importance of environmental variation on the distribution and flowering of A. elata at both microhabitat and site-level scales. At four sites encompassing a variety of forest types, we measured several biotic and abiotic variables at vegetative and reproductive plants, as well as at random points. We measured these same variables at three sites where A. elata has been extirpated. Within occupied sites, reproductive plants were more likely to be located in canopy gaps than were vegetative plants. Both vegetative and reproductive plants were more likely to be found in areas of high herb cover compared to random points. These results indicate that gaps in the canopy may be critical for this species’ ability to reproduce, but survival may be possible in a broader range of forest understory conditions (similar to other co-occurring herb species). Random points at extirpated and occupied sites both tended to be located in areas of lower canopy openness and moisture availability than points in occupied sites where A. elata was present. Extirpated sites were either densely forested or clearcut, while occupied sites contained stands of intermediate density. Circaea alpina, Geranium robertianum, and Lactuca muralis were indicator species for A. elata and normally indicate moist soils, with Circaea alpina being a strong indicator of the presence of flowering A. elata. Taken together, our results suggest that maintenance of canopy gaps is important to promote flowering, and understory species that indicate moist sites, particularly Circaea alpina, can be used as aids to locate new populations of A. elata.     

A single dominant Ganoderma species is responsible for root rot of Acacia mangium and Eucalyptus in Sumatra

Ganoderma root rot is the most serious disease affecting commercially planted Acacia mangium in plantations in Indonesia. Numerous Ganoderma spp. have been recorded from diseased trees of this species and to a lesser extent Eucalyptus, causing confusion regarding the primary cause of the disease. In this study, a large collection of Ganoderma isolates were obtained from the roots of A. mangium showing early signs of root rot in disease centres in South Sumatra plantations. Isolates were also collected from Eucalyptus roots at Lake Toba in North Sumatra showing similar symptoms as well as from sporocarps connected to these samples. Phylogenetic analyses showed that a single Ganoderma sp., identified as G. philippii, is the major causal agent of Ganoderma root rot on A. mangium. Results from this study also showed that the isolates obtained for Eucalyptus trees in North Sumatra belong to G. philippii. Isolates from roots and connected fruiting bodies together with the morphology of the fruiting structures confirmed this identification. Symptoms associated with this pathogen are obvious and it should not be confused with other diseases. Other Ganoderma spp. found in disease centres are considered to be of minor importance and management strategies for root rot should be focused on G. philippii.     

Development and use of new sensitive molecular tools for diagnosis and detection of Melampsora rusts on cultivated poplar

Poplar rusts due to Melampsora larici‐populina (Mlp), M. allii‐populina (Map) and M. medusae f. sp. deltoidae (Mmd) are the most serious disease in Europe on cultivated poplars, that is, Populus × euramericana and P. × interamericana hybrids. These pathogenic species can be identified by the observation of morphological characteristics of urediniospores but this method is not appropriate for high‐throughput analysis and cannot be used on other spore stages, such as aeciospores or teliospores, that are morphologically similar. The aim of this study was to develop a rapid and sensitive molecular method based on PCR amplification that was able to specifically detect these species on various hosts for routine analysis. Three primer pairs ITS‐MLP‐F/ITS‐MLP‐R, ITS‐MAP‐F/ITS‐MAP‐R and ITS‐MMD‐F/ITS‐MMD‐R were designed within the internal transcribed spacer (ITS) sequences of ribosomal DNA to target Mlp, Map and Mmd, respectively, and their specificity were confirmed on a wide range of isolates and species. ITS‐MLP‐F/ITS‐MLP‐R and ITS‐MAP‐F/ITS‐MAP‐R primers proved to be highly specific to Mlp and Map, respectively, whereas ITS‐MMD‐F/ITS‐MMD‐R cross‐reacted with DNA from M. larici‐tremulae and M. pinitorqua. However, these species are not pathogenic on cultivated poplars that all belong to sections Aigeiros and Tacamahaca of the genus Populus. Specific Mmd primers proved to be very sensitive as a positive signal could be obtained with DNA extracts from 6 target urediniospores mixed with 800 000 urediniospores of Mlp. An internal amplification control (IAC) was included to discriminate false negative results due to the potential presence of inhibitory compounds in DNA extracts. ITS‐MMD‐F/ITS‐MMD‐R primers are therefore efficient for the detection of the quarantine pathogen Mmd on samples collected on poplar or larch and are fit for use in official tests. This new PCR assay has been used in routine for ten years, and Mmd has hitherto never been detected in commercial poplar nurseries in France.     

High‐resolution melting analysis allows rapid and accurate differentiation of the three Melampsoridium species occurring on Alnus

Alder (Alnus) leaves can be infected by three species of Melampsoridium rust: M. alni, M. betulinum and M. hiratsukanum. The latter is an invasive species in Europe that can be differentiated from the other two on the basis of morphological and molecular characters. This study presents a rapid, one‐step, closed‐tube and inexpensive method to differentiate species of Melampsoridium using two primer sets and high‐resolution melting (HRM) analysis of alder leaf material.     

Future outlook for Pinus patula in South Africa in the presence of the pitch canker fungus (Fusarium circinatum)

Approximately 50% of the area planted to softwood trees in South Africa has been established with Pinus patula, making it the most important pine species in the country. More effort has gone into developing this species for improved growth, tree form and wood properties than with any other species. This substantial investment has been threatened in the last 10 years by the pitch canker fungus, Fusarium circinatum. The fungus infects and contaminates nursery plants and, once transferred to the field, causes severe mortality of young trees in the first year after establishment. Although nurserymen have some control of the disease, it is recognised that the best long-term solution to mitigate damage because of F. circinatum infection is to identify tolerant species, clones and hybrids for deployment in plantations in the future. Research has shown that alternative species such as P. tecunumanii, P. maximinoi and P. elliottii are suitable for warm sites. Pine hybrids, particularly between P. patula and the high-elevation sources of P. tecunumanii, appear to be a suitable replacement on subtemperate and temperate sites. Although these alternative species and hybrids are more sensitive to subfreezing temperatures than P. patula, their planting range can be increased by including cold tolerance as a selection criterion. Future breeding efforts will most certainly focus on improving the tolerance of pure P. patula to F. circinatum, which can be achieved by identifying specific family crosses and tolerant clones. The commercial deployment of disease-tolerant control-pollinated P. patula and hybrid families will most likely be established as rooted cuttings, which requires more advanced propagation technology. In the long term, new seed orchards comprised of P. patula clones tolerant to F. circinatum could be used to produce seed for seedling production.     

Allometric model of the height–diameter curve for even-aged pure stands of Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>)

We derived an allometric model of the height–diameter curve for even-aged pure stands, which was a modification of the earlier model proposed by Inoue (2000a). An individual-dependent allometric equation was used as the height–diameter curve. Using the discriminant analysis method, all trees composed of a stand were stratified into upper and lower trees. It was assumed that both relationships between mean tree height H _m and upper tree height H _u and between mean DBH D _m and mean DBH of upper trees D _u could be described by the time-dependent allometric power equations. The height–diameter curve showed an average relationship between tree height and DBH of a given stand at a given time, and hence it could be assumed that the height–diameter curve contained two points (D _m , H _m ) and (D _u , H _u ). With these assumptions, we derived an allometirc model of height–diameter curve, which allowed the coefficients of the curve to be estimated from mean tree height and mean DBH. The proposed model was fitted to Japanese cedar (Cryptomeria japonica D. Don) data. The error ratio of the allometric model ranged from 2.254% to 13.412% (mean = 6.785%), which was significantly smaller than that of the earlier model. When the error of mean tree height was ±1.0 m or less, the effect of the error of mean tree height on the error ratio was comparatively small. This suggested that the error of ±1.0 m in mean tree height could be accepted in the estimation of height–diameter curve using the allometric model. These features enable us to combine the allometric model with Hirata’s vertical angle-count sampling or growth models. In conclusion, the allometric model would be one of the most practical and convenient approaches for estimating the height–diameter relationship of even-aged pure stands.     

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.     

Genetic variation in three Ceratocystis species with outcrossing,selfing and asexual reproductive strategies

Nuclear and mitochondrial markers were used to examine variation within three closely related species of tree pathogens with differing reproductive strategies. Ceratocystis eucalypti is obligately outcrossing; Ceratocystis virescens is capable of selfing due to unidirectional mating type switching; and Chalara australis is an asexual species, comprised of a single mating type. When the nuclear DNA fingerprinting markers (CAT)₅ and (CAG)₅ were used as probes against Pst I-restricted DNA, isolates of C. eucalypti were found to be highly polymorphic, and Ch. australis showed very little polymorphism. The selfing C. virescens showed an intermediate level of variation in the nuclear fingerprint markers, and much of the variation appeared to be due to differences between two forms of the species, one pathogenic to Acer and Liriodendron and another less-pathogenic form on Fagus and other hardwoods. Mitochondrial DNA (mtDNA) polymorphisms were examined by digesting total DNA with Hae III or CfoI, and C. eucalypti showed somewhat more variation in mtDNA than did C. virescens. The only polymorphism seen in the mtDNA of Ch. australis was associated with a plasmid. Selfing in C. virescens may be common and could explain an intermediate level of diversity when compared to the obligately outcrossing C. eucalypti and the asexual Ch. australis.     

Nondestructive test and prediction of modulus of elasticity of veneer-overlaid particleboard composite

The effects of grain angle, thickness of face veneer, and shelling ratio on dynamic modulus of elasticity (E) of veneer-overlaid particleboard composite (VOP) were examined by using nondestructive test. In this study, the possibility that E of VOP can be predicted by means of some empirical formula was also discussed. This study has shown that grain angle, thickness of face veneer, and shelling ratio have substantial effects on E of VOP. The E at 0° of grain angle of face veneer was the largest, decreasing rapidly with increase in the grain angle. The lowest value of E occurred at 90° of grain angle of face veneer. The relationship between grain angle of face veneer and E of VOP can be expressed in the form of Jenkin’s and Hankinson’s equations. The orthotropic properties of wood and VOP defined as the ratio E ₀/ E ₉₀ were 25.7 for wood and 4.7 for VOP. When the grain direction of face veneer was parallel to the length of the specimens, the E of VOP increased with increasing shelling ratio. VOP increased E from 125 to 179% over that of the particleboard and veneer thickness from 2.1 upto 3.6 mm. However, when the grain direction of face veneer was perpendicular to the length of the specimens, the E of VOP decreased with increasing shelling ratio. VOP decreased E from 23 to 41% over that of the particleboard and veneer thickness from 2.1 upto 3.6 mm. The relationship between E of VOP and face veneer thickness can be expressed in the form of a second-order parabolic equation. Rule of Mixture (ROM) can be used to predict E of VOP from the E of wood element and particleboard element.     

Discrimination of Bursaphelenchus xylophilus and Bursaphelencus mucronatus by PCR-RFLP technique

A polymerase chain reaction-restriction fragment length polymorphism analysis was used to discriminate isolates of Bursaphelenchus xylophilus and B. mucronatus. The amplifications of B. xylophilus isolates yielded one fragment of approximately 890 bp and that of B. mucronatus was about 930 bp. Digestion of amplified products of each nematode isolate with five restriction endonucleases revealed the following results: 1) Dra I digestion of the internal transcribed spacer (ITS) products of B. xylophilus populations yielded two fragments of 510 and 380 bp. Dra I could not digest the ITS products of B. mucronatus populations; 2) Sal I could not digest the ITS products of all B. xylophilus populations, but it could digest those of B. mucronatus populations into two fragments, which were 720 and 220 bp; 3) digested products of four B. xylophilus populations by Msp I yielded two fragments of 530 and 360 bp, except GZ02, which could not be digested. B. mucronatus populations yielded three fragments: 340, 290, and 180 bp; 4) all populations of B. xylophilus and B. mucronatus could not be digested by Apa I; 5) digestion of the ITS products of B. xylophilus and B. mucronatus yielded two fragments of 520 and 370 bp, and 530 and 400 bp respectively. The restriction endonucleases Dra I and Sal I could be used to identify B. xylophilus and B. mucronatus. Because the results of digestion of B. xylophilus and B. mucronatus were markedly different, they were very easy to be identified and applied; Msp I and Xho I were not suitable for identification of B. xylophilus and B. mucronatus and Apa I could not identify and distinguish between B. xylophilus and B. mucronatus. __________ Translated from Journal of Nanjing Forestry University, 2005, 30(4): 5–9 [译自: 南京林业大学学报]     

基因分化值和基因调控信息量研究

本文通过对基因调控、表达的分析,探讨了个体分化定量问题,提出用基因分化值D_(?)指标,度量分化细胞之间的内部差异;对调控、表达问题,用信息论的方法加以处理,得到了基因调控熵H_r,再从H_r指标估算出调控信息量。D_(?)具有强度性质;H_r具有容量性质。试验选用同功酶测定这两项分化指标。再用这两项指标进一步讨论分化、进化、生物信息、群体复杂性等问题。