Stand structure and plant species occurrence in forest edge habitat along different aged roads on Okinawa Island, southwestern Japan

We compared stand structure and plant species occurrence on the shoulders of 3-, 10- and 20-year-old roads in a subtropical evergreen broad-leaved forest to document temporal changes in edge effects of forest roads. We recorded 154 vascular species in the study plots, including 3 non-native species. We used generalized linear mixed models to analyze changes in forest structure and plant species composition in relationship to the distance from forest roads. The spatial patterns in stand structure at different distances from roads differed with road age. The large canopy openness on the edge of 3-year-old roads decreased with time after the construction. A progressive decrease in tree height on roadsides was observed after the road construction, suggesting tall trees could not withstand the dry and windy roadside environment. The edge effect on the canopy tended to be larger at higher elevation sites. The spatio-temporal pattern of species occurrence based on distance from roads differed by species. Typical pioneer species such as Schima wallichii and Eurya japonica increased along the edge, while less aggressive pioneer species and understory species decreased. As time passed after the road construction, some climax and understory species decreased at the forest edge, while other climax and understory species increased. The modeling methods proposed in this study could be applied to different roadside and edge study sites.     

关于改革和完善集体林采伐管理的思考

总结吉林省集体林采伐管理情况及取得的成效,结合集体林权制度改革的深入开展,针对集体林采伐管理面临的主要问题,提出新形势下改革和完善集体林采伐管理的建议和对策     

Early response of stand structure and species diversity to strip-clearcut in a subtropical evergreen broad-leaved forest in Okinawa Island, Japan

Natural regeneration by strip-clearcut has rarely been used for restocking of evergreen broad-leaved forests in the East Asia. To contribute to a better understanding of the likely reasons for either the successful recovery of these forests or failure, the early response of stand structure and tree species diversity to strip-clearcut were studied in Okinawa Island, southwest Japan. The 4,000 m² study area was divided into 10 adjacent sections of equal area with a 10 m × 10 m sampling plot in the center, of which five sections were strip-clearcut while the remaining five sections uncut. Eight-year secondary succession following strip-clearcut showed that the density of woody stems, tree species diversity increased significantly not only in the regenerating stands but also in the residual stands compared to the primary stands. The primary dominant target species, Castanopsis sieboldii, continued to dominate both the regenerating and residual stands although colonizing species invaded abundantly in the stands, occupying approximately one-third of total tree species in each treatment. The community similarity analyses showed that the species composition were similar between the primary stands and the regenerating stands or residual stands reflected the high similarity amongst the primary stands and the regenerating stands or the residual stands. The similar stand structure, high tree species diversity and greater community similarity after strip-clearcut provided no evidence of forest degeneration, suggesting that the regenerating stand might gradually develop into stand similar to that prior to strip-clearcut.     

Diversity and community structure of wood-inhabiting fungi found in Japanese wooden houses analyzed by the next-generation sequencing

The diversity and community structures of wood-inhabiting fungi in 16 decayed wood samples from ten wooden houses in Japan were analyzed using a next-generation sequencing (NGS) to determine the fungi responsible for wood decay. DNA of fungi in decayed wood was extracted directly, the internal transcribed spacer (ITS) region in ribosomal DNA (rDNA) was amplified by polymerase chain reaction (PCR), and then, sequences of tagged ITS fragments were analyzed by NGS. Results of sequencing indicated that 68 species of ascomycetes, 37 species of basidiomycetes, and one fungus each from Mortierellales and Mucoromycetes were detected. The fungal community structures showed diversity and included various species of ascomycetes. A microscopic examination of cell wall structure in decayed wood samples suggested that some ascomycetes were soft-rot fungi. Heat map analysis indicated that the similarity in the structures of fungal communities was influenced to a greater extent by the wood species of samples than where they were used as a component.     

General principles in the community ecology of ectomycorrhizal fungi

Introduction

Knowledge of the factors that determine ectomycorrhizal fungal community structure is essential in many areas of practical significance including conservation, habitat restoration, prevention or amelioration of species invasions, and the prediction of responses to climate change. With respect to these goals, however, community ecology, in general, and ectomycorrhizal fungal community ecology, in particular, have been rather disappointing.

Discussion

Indeed, some feel that community ecology is, at best, an esoteric discipline and, at worst, an inane one. But there is hope. As we apply what has been learned about other organisms concerning the relationships between functional traits and success (abundance), it may be possible to elucidate general principles that govern much of the structuring of ectomycorrhizal fungal communities.

Conclusion

A hierarchical model of ectomycorrhizal fungal community structure is presented that involves abiotic filtering of immigrant propagules based on functional traits, followed by interspecific competition as ameliorated by disturbance and habitat partitioning, the outcomes of which are dependent on functional traits.     

上海大金山岛的自然植物群落多样性

<正>大金山岛位于上海西南角的杭州湾中(E121°24′-25′,N30°41′-42′),面积0.3km2,最高点的海拔高度为105.03m,是上海市地面最高点。该岛地处中亚热带北缘,受东亚季风以及太平洋暖湿气团的影响,四周被水域包围,属海洋性气候,温和湿润,四季分明。年平均温度16℃,最冷月(1月)平均温度为3.3℃,年平均降雨量大于1000mm。Kira的温暖指数(WI)为130.2℃·月,寒冷指数(CI)为-2.1℃·月。土壤为地带性的褐色山地黄壤,厚约1m,pH值4.5~4.7。     

伞伐更新法对赫卡尼亚(Hyrcanian)森林系统中森林再生和林分结构的影响

研究伞伐更新法对赫卡尼亚森林系统中森林再生和林分结构的影响。在伊朗北部优势种为山毛榉（Fagus orientalisLipsky）的硬木林,采取伞伐更新法和非伞伐更新法方法设计实验区。结果表明,在山毛榉（F orientalis Lipsky）林中采用伞伐更新法处理,明显影响林下草本植物种的频度和密度。伞伐更新法处理后,林堇菜（Viola silvestris Lam.）、车叶草（Asperula odorata L.）、苔草（Carex spp.）和悬钩子（Rubushyrcanus Juz）的种频度明显增加。在对照区,树种的胸高直径（57.50&#177;2.15cm）大于被处理区（50.67&#177;1.88cm）的树种的胸高直径（50.67&#177;1.88 cm）,但对照区和处理区的树种的高度值相似。在1995-2005年间,波斯铁木（Parrotia persica）苗木数量增加到13.2%,而山毛榉（F orientalis）和欧洲鹅耳枥（Carpinus betulus）的苗木数量却明显减少。总之,应该利用其它育林方法,如,带状择伐作业,而不是伞伐更新法培育赫卡尼亚森林中山毛榉林。     

Structure and species diversity of subtropical evergreen broad-leaved forest in northern Okinawa Island, Japan

The structure and tree species diversity of a subtropical evergreen broad-leaved forest in northern Okinawa Island, Japan, were studied. Enumeration of the six sampling plots revealed an average density of 5,580 individuals with DBH≧3.0 cm/ha, having an average basal area of 55 m². The large-size trees of DBH≧20 cm contributed 10% of the total individuals, and 49% of the total basal area. The forest showed a high diversity of tree species, which is comparable to some tropical rain forests. A total of 54 over-story species of 24 families and a total of 63 understory species of 26 families were identified in the six sampling plots. Fagaceae and Theaceae were the most important families;Castanopsis sieboldii, Schima wallichii andDistylium racemosum were the most important species. The diversity index and equitability index of species were 4.15 and 0.72 for the overstory plots, and 4.72 and 0.79 for the understory subplots, respectively. The diversity index for the overstory was significantly correlated to the total basal area of trees over 20 cm DBH (p<0.05) and the importance value ofC. sieboldii (p<0.001), while for understory, the diversity index was not correlated to the structural parameters (allp>0.16). The size distribution pattern and age structure indicated differences in regeneration strategies for canopy dominants. In population dynamics of the succession process,C. sieboldii andD. racemosum were self-maintaining types, andS. wallichii was a gap- or opening-dependent type. This study was made possible by support from the Japanese Ministry of Education, Sciences, Sports and Culture, which provided a Monbusho scholarship to X.N. Xu.     

扦插密度对柳树苗木的影响

试验结果表明,在立地条件,管理措施、插条质量相同的条件下,柳树扦插密度以3170株/亩为最好,其株行距为30×70厘米。     

Effect of Cutting Speed on Surface Quality by Bandsawing

Introducti0nSincetI1ebandsa\`canbequickl}'andaccLIratel}'setal1dtllereisvirtuaII};noupper-sizeIilnitinIogdiameter,tI1emachinecanberegardedasthemosleffectiveaII-r0undmachine.Lumbermillsshowgro\"inginterestintI1ebal1dsawingconceptduetotl1el1ighthroLIghputan…     

生长激素对杜鹃红山茶扦插效果的影响

研究了不同扦插时期和不同植物生长激素对杜鹃红山茶扦插繁殖效果的影响。结果表明:杜鹃红山茶的春季和夏季扦插无显著性差异,而植物生长激素处理对杜鹃红山茶的成活率、平均生根数、平均根长、平均抽梢次数和平均苗高有显著影响(p<0.05)。在13种激素处理中,效果最好的是0.5 g/L的混合植物生长激素组合(80%IBA+20%NAA)。植物生长激素组合(80%IBA+20%NAA)的扦插效果优于NAA和IBA单独使用。     

不同采伐强度对闽西常绿阔叶林林分结构稳定性的影响

应用多样性分析方法和改进后的 M.Godron 稳定性测定方法研究常绿阔叶林5种不同强度采伐(弱度9.8%、中度24.5%,强度46.8%和极强度72.3%和皆伐)作业10 a后林分结构稳定性.结果表明,择伐林地林分处于稳定状态,随着择伐强度的增强,林分的稳定性开始逐渐降低.皆伐林地林分处于不稳定状态.对于常绿阔叶林的科学经营,从稳定性出发,应尽量采取择伐方式,尤其是中低强度的择伐方式.     

Effect of ectomycorrhizal fungi on bacterial wilt of Eucalyptus

Bacterial wilt caused by Pseudomonas solanacearum, is a very serious disease of Eucalyptus in southern China, mainly in Guangdong, Hainan and Guangxi provinces. It causes the death of seedlings and young trees and the mortality may exceed 90 percent in some sites. Susceptible species include E. grandis, E. urophylla, hybrids between the two and E. citriodora. In nursery and field trials with E. urophylla and field trial with E. grandis x E. urophylla inoculation of ectomycorrhizal fungi was found to reduce the incidence of the disease. Some fungal isolates were more effective than others.     

Effect of selective cutting type on the chainsaw productivity in Caspian Forests

Time and motion studies were conducted to evaluate the impact of selective cutting type on Chainsaw productivity in Caspian forests,the selective cutting performed as single and group selection cutting in the region.The selective cutting was performed on a 42-ha tract with an average slope of 30%.The results indicate that felling time for per tree is most affected by diameter at breast height,the distance among harvested trees in single-tree selection method and diameter at breast height in group selection method.The production rate in single and group selection cutting were 21.2 m 3 h-1 and 28.4 m 3 h-1 for one person,respectively.Considering the gross and net production rate in single and group selection cutting,the unit cost was 1.11 USD m-3 and 0.88 USD m-3,respectively.The results indicate that group selection cutting can be more profitable than single-tree selection method.     

4WS2000高杆芦苇收割机割台的设计

通过对芦苇收割机割台的研究,对比目前常用芦苇收割机割台存在的优缺点,提出了WS2000高杆芦苇收割机割台的设计方案。割台是收割机的关键部件,是分苇、扶苇机构、拨苇轮、割刀、横向输送等机构的组合体;给出了这些机构的设计方案,分析了其受力情况及工作原理,并考虑实际作业情况及整体机构的协调工作。     

Ecological succession of a natural community of Castanopsis sclerophylla on Laoshan Island,China

Castanopsis sclerophylla was surveyed for its root turion capacity on Laoshan Island in Zhejiang Province and dispersion patterns of seedlings,genetic diversity and genetic variation coefficient was studied using a SSR(simple sequence repeat) molecular marker technique to explore the genetic diversity of C.sclerophylla(Lindl.) Schott as a community and evaluate the community's development.The results showed that C.sclerophylla had strong root turion capacity,of which type Re2 was the most frequent,accounting for 32.4 and 82.4 % of the seedlings under the stock plant were from within-community mating;the 6 pairs of SSR primers chosen yielded high resolution with 97.6 % polymorphic sites;the within-community genetic diversity was over 88.9 % with stock plants(0.49)[seedling plants(0.45).Apparently,C.scerophyllan on Laoshan Island,propagating mainly by root turions,has developed high genetic diversity within a short period,keeping the community in a stage of stable growth and moving toward a climax community.The tillers,however,aggravate closing of the community so that it receives less pollen from outside.Within-community mating is thus reaching seriously high levels,which can lead to lower within-community genetic variation,a decline in DNA genetic diversity,and is bad for its development.Therefore,human interference should be taken to expand genetic exchange among communities.     

提高沙棘嫩枝扦插成活率的几项关键技术

介绍了沙棘嫩枝扦插的苗床建造标准，插条的处理和提高插条自身抗病力的三项林业技术措施以及需要注意的问题。表明沙棘嫩枝扦插成活率的提高是一项综合性整体的细致入微的配套技术。     

板栗园季节性节肢动物群落结构研究

该文对4种不同管理和不同生境板栗园节肢动物群落及其多样性进行了研究。研究结果表明,板栗园节肢动物隶属于11目54科106种;板栗园以针叶小爪螨最多,占类群总个体数的98.9179%。针叶小爪螨是影响不同管理和生境板栗园节肢动物群落多样性指数、均匀度、优势集中性指数的主要因子。板栗节肢动物群落的物种丰富度随针叶小爪螨的降低而降低,种群的稳定性因针叶小爪螨的降低而加强。科学合理的选择农药、管理板栗园既能维持群落一定的丰富度、多样性,又能减少害虫优势种群的虫口数量。     

Changes of community characteristics of a broad-leaved-conifer mixed forest after selection cutting

IntroductionSpeciesdiversityisaffCctedbyl1atureddistllrhal1ce,sucl1aswindandfireli1variousways,mosllydepel1dingol1gapsizeandgapdensity,aswel1asdisturbal1cefrequellcy(Poulsonetal.l989).However,al1aIltl1r('pic`Iistuthal1cesuchascIearcuttiIlginlargearean1ayleadtolllecliversityintl1elowestlevelandthesimpleststructllre,wllileaproPerselectioncuttingreginlen1ayl1eIpreleasellleil1di-vidualsuppresscdul1derh1ecal1()py(Ca11llanll988).Cut-ting,especiallyalsobringsmodificationillverticalstrataa11dspeci…     

插穗对沙棘嫩枝扦插育苗的影响

主要研究了全光照喷雾条件下，采条母树树龄及插穗留叶方式、粗度对沙棘嫩枝扦插生根率的影响。结果表明，留叶方式对沙棘嫩枝扦插生根率有着极显著的影响，有顶梢留叶多的插穗生根率高，无顶梢时，留叶量多的扦穗生根率高；扦穗粗度及母树树龄对沙棘嫩枝扦插生根率有着显著的影响，生长充实、较为粗壮，树龄在3－6龄之间的母树插穗扦插生根率高。