秋施硼肥在苹果植株中的分布与利用动态

对盆栽苹果树施Ｈ３１０ＢＯ３,于主要物候期测定,结果表明,生长季地上部全Ｂ的变化呈双峰曲线,根系仅出现一次高峰;枝条与粗根皮层的全Ｂ量一般比木质部高３～４倍,但从肥料中吸收的Ｂ占全Ｂ量的百分率（Ｂｄｆ％）二者相差无几。地上部新生器官在新梢旺长期Ｂｄｆ％值迅速提高,其后处于高水平的相对稳定期,细根随时间进展不断下降,粗根则缓慢上升。秋施１０Ｂ肥后的第３年花期测定植株不同器官的Ｂｄｆ％值仍可达１２．７％～３３．６％,而土壤仅为４．２％,并且１０Ｂ在植株中的分布发生了变化,一年生枝与粗根含量显著上升,约比翌年同期增加２倍左右,而主干与细根含量显著下降,说明硼肥在树体内具有长效作用,可再利用。     

An analysis of structure of tree seedling populations on a Lahar

The structure of a tree seedling population is dependent on the interaction of several processes including seed dispersal, germination, survival, and competition on a physical landscape. Structural components (composition, size distributions, spatial distributions, age distributions, density, and history) of a tree seedling population on the Muddy River Lahar on the east side of Mount St. Helens were examined over a range of extents (1/10 m to 1000 m). Many of these component have rarely been examined at the larger extents listed here. Composition reflected distances to seed source and seed morphology. Seedling sizes are inversely proportional to depth to a buried soil if one existed. Spatial patterns indicated that seedling are clustered for tree seedlings less than 200 m apart, random for tree seedling from 200 m to 400 m and uniform for seedling greater than 400 m apart. This was confirmed by two measures of multidimensional spatial point pattern. Age distributions did not reflect the size distributions; old seedlings could be almost any size, young seedlings were constrained to be small in size. Densities appear to be typical for forests in the area. History of disturbance events (the lahar establishment, and successive ash, pumice, and erosion) has strongly influenced this tree seedling community.     

Urban permeability for birds: An approach combining mobbing-call experiments and circuit theory

The urban matrix was recently shown to be a mosaic of heterogeneous dispersal habitats. We conducted a playback experiment of mobbing calls to examine the probabilities of forest birds to cross a distance of 50 m over urban matrix with different land-cover types in an urban area. We treated the reciprocal of the crossing probabilities as a movement resistance for forest birds. We drew resistance surfaces based on the land-cover maps of urban Sapporo. We applied a circuit theory to examine the relative role of a detour route consisting of a riparian corridor and urban matrix for dispersing forest bird individuals from continuous forest to an isolated green space in the midst of an urban area. Our results showed that wood cover had the highest crossing probability, while open land (grassland and pavement) had the lowest probabilities. Buildings and water surface displayed an intermediate probability. Resistance surfaces and flow maps at 25- and 50-m resolutions were very similar and suggested that dispersing individuals are likely to use the intervening building areas that dominate the urban matrix rather than detour through riparian corridors. Our results showed the useful combination of experimental approaches and circuit theory, and the importance of the spatial configuration of corridors, as well as the composition and management of dispersal habitats, to landscape connectivity.     

民营橡胶发展提升探析

民营橡胶是我国天然橡胶产业的重要力量和区域特色产业的重要组成部分。本文探讨分析目前民营橡胶生产发展中存在的科学植胶意识不强，胶园生产能力偏低，技术力量薄弱，橡胶树病虫害防控能力不强，民营橡胶产品质量有待提高等问题。提出通过树立科学的植胶观念，增强科学植胶意识，加强橡胶树先进适用技术的集成配套及推广应用，采取多种形式增强民营橡胶技术力量，增强民营橡胶自身病虫害防控能力，提高民营橡胶产品质量水平等途径，提升民营橡胶整体发展质量水平和市场竞争能力。     

姥山马尾松1代种子园良种选育

经过１０多年努力，姥山马尾松１代无性系种子园建成投产，经造林测定，６年生子代林的树高、胸径、村积生长量分别比对照提高１５．２％、１８．４％、５６．８％．良种效益显著，并经浙江省林木良种审定委员会审定通过。     

一种树的存储结构

采用静态数组的方式给出树的一种存储结构，并给出这种存储结构下的几种常用运逄的Ｃ语言程序，这种存储结构避开了链式存储结构中链域个数不定的困难，容易用ＦｏｘＢＡＳＥ等关系型数据库来实现相应的运算，可以将二叉树与树统一起来处理。     

Tree Diversity,Carbon Storage,and Soil Nutrient in an Old‐Growth Forest at Changbai Mountain,Northeast China

Abstract

The study of plant diversity and its role in ecosystem functioning is becoming a central issue in ecology. The relationships between carbon storage and tree diversity of natural forest at small scale are still unclear. This research investigated these relationships in an old‐growth forest at Changbai Mountain, Northeast China. It was found that at small scale, tree carbon storage generally increases with increasing tree species richness, but for stands with same species richness, tree carbon storage varies dramatically. At the small scale, tree species evenness has a significantly linear relationship with nature logarithm of total tree carbon storage. The stand carbon storage of trees is mainly controlled by stand tree composition. Fraxinus mandshurica, Pinus koraiensis, Quercus mongolica, Tilia amurensis, and Acer mono contribute more than 85% of stand carbon storage of trees. Stands with similar tree composition at small scale have different soil organic carbon storage and nutrient contents. Tree species evenness has great impact on soil N content at the soil horizon less than 30 cm deep, but its impacts on C/N, P, K, and S contents are small. Tree density has a negative linear relationship with soil organic C and C∶N ratio at the soil horizon is less than 30 cm deep. The implication of our findings here for carbon sequestration in the Kyoto Protocol is also discussed.     

山地杏树栽培管理

山地杏树栽培应注意土肥水管理、整形修剪、生长期管理、病虫害防治几个关键环节,根据多年的生产实践现介绍几点经验,以供生产经营者参考。     

鹅掌楸及其在园林绿化中的应用

鹅掌楸树形端直、叶形奇特、花朵酷似郁金香,是世界著名的观赏树种,利用历史悠久。依据相关文献概述了鹅掌楸的种质类型、分布特征,总结了其文化内涵和生态习性,重点阐述了鹅掌楸在园林绿化中的应用,并对进一步开发利用进行了展望。