延边地区水田分等的数学模型

本文利用模糊数学和统计的方法，通过采集样本，建立了一个多元隶属函数，提出了一种延边地区水田分等的数学模型．本模型对于任一参评地块，只要将其各指标值标准化后代入所建立的函数，即可得知该地块的等级．该模型具有合理、简便的特点．     

Potential for reintroduction of lake sturgeon in five northern Lake Michigan tributaries: a habitat suitability perspective

• 1. Conservation and rehabilitation efforts for lake sturgeon Acipenser fulvescens throughout the Great Lakes include the re‐establishment of self‐sustaining stocks in systems where they have been extirpated.
• 2. Information on the suitability of potential lake sturgeon habitat in tributaries is important for determining their capacity to support lake sturgeon stocking and to develop system‐specific rehabilitation strategies.
• 3. Geo‐referenced habitat information characterizing substrate composition, water depth, and stream gradient were applied to a life‐stage specific lake sturgeon habitat suitability index in a geographic information system to produce spatially explicit models of life‐stage specific habitat characteristics in five northern Lake Michigan tributaries from which lake sturgeon have been extirpated.
• 4. Habitat models indicated that high quality lake sturgeon spawning and staging habitat comprised 0 to 23% and 0 to 9% of the available habitat, respectively, whereas high quality juvenile lake sturgeon habitat was relatively ubiquitous throughout each river and comprised 39 to 99%.
• 5. Comparison of these data to lake sturgeon habitat availability in Lake Michigan tributaries currently supporting populations indicated that spawning and staging habitats may limit the ability of these systems to support spawning. Efforts to re‐establish lake sturgeon populations in these systems should consider the creation of spawning and staging habitat to increase reproductive and recruitment potential prior to the initiation of stocking efforts.

Copyright © 2007 John Wiley & Sons, Ltd.     

园林常见树种病虫害调查与防治

人类的过度建设,忽略了植物群落稳定的建设,不同程度地改变了城市环境和自然植被(natural vegetation)生境,盲目引种外来植物,导致了城市园林植物病虫害的不同程度的发生。通过对常见园林树木病虫害调查分析,总结了一些基本防治方法,为园林树木种植、管理提供参考资料。     

4S-6型大蒜收获机性能参数试验与分析

对4S-6型大蒜收获机进行了田间性能试验,采用多因素多水平的正交试验设计,研究了设计参数对性能指标的影响,对试验数据进行分析,找出了影响损失率、伤蒜率等主要性能指标的主次因素及较优组合,得到了各因素水平间的差异显著性,并对生产率进行了计算,为大蒜收获机的改进设计提供了依据。     

云南热作所微割采胶试验总结报告

报道云南最早进行橡胶树微割采胶试验的结果。结果表明，微割采胶的株产、株次产都高于对照常规割胶，年平均净增产率为5.78%，干胶含量比对照低1～4个百分点；割胶速度为对照的2～3倍；耗皮量为对照的20%～25%；累计死皮率为4.04%，低于对照(5.91%)，为常规割胶的68.36%，胶乳生理参数保持正常水平。     

德国核桃‘No.120''幼胚胚轴与子叶体细胞胚胎发生及其植株再生

核桃 (Juglansregia)‘No . 12 0’品系授粉 7～ 8周的幼胚胚轴与子叶在含不同植物生长调节剂组合的诱导培养基上培养 4周后转移至无植物生长调节剂的继代培养基上培养 ,不同发育时期的体细胞胚直接形成于胚轴与子叶表面。子叶与胚轴分别在KT 2mg/L BA1mg/L IBA 0 .0 1mg/L与 2 ,4 D 2mg/L KT 1mg/L的组合的诱导下体细胞胚胎发生频率最高。体细胞胚经 3～ 5℃低温处理 2个月 ,31.6%的体细胞胚能发育成正常生长的植株     

枇杷属植物落黄叶片颜色遗传多样性分析

调查发现枇杷属(Eriobotrya)植物种质落黄叶片有红褐色、金黄色、紫红色等24种代表性色泽。通过便携式色差仪观测枇杷属10个种176份种质落黄叶片正面和背面的色泽参数,探讨落黄叶片颜色的遗传多样性特征。结果表明:(1)枇杷属植物落黄叶片正面和背面的色泽参数L、a、b值变异系数差异较大,变幅为8.65%~185.30%,Shannon’s遗传多样性指数为1.95,说明落黄叶片色泽变异多样;(2)不同种质类群间和不同来源地类群间的变异系数和Shannon’s遗传多样性指数差异均较明显,呈现出栽培驯化程度越高,落黄叶片正面和背面的b值变异系数越小和a值变异系数越大的趋势;云南、贵州、福建地区的类群多样性指数较高;(3)系统聚类将落黄叶片正面色泽划分成12组,背面分成10组,且各组内所包含的枇杷种质类型差异大;(4)L值、b值对落黄叶片正面和背面的系统聚类分析贡献率均较大,落黄叶片正面L值与背面b值呈极显著正相关;(5)落黄叶片颜色的遗传多样性可作为枇杷属植物形态学特征描述的补充,为枇杷属植物的鉴别和利用提供新的参考,对枇杷分类研究具有潜在价值。     

Effects of best management practices on dry matter production and fruit production efficiency of oil palm

Enhancing dry matter production with higher partitioning to fruit bunches is important for sustainable intensification of oil palm. A series of best management practices including site-specific nutrient management, canopy management, and harvesting has been developed for oil palm plantations. However, the effects of these practices on dry matter production and partitioning, and how the effects vary with climatic and soil conditions of plantation sites, remain largely unknown. We established a four-year field trial including 30 paired commercial blocks across Sumatra and Kalimantan, Indonesia. The paired treatments included site-specific best management practices, and standard estate practices as the control. The annual production of aboveground dry matter was 30.0 ± 0.5 t ha⁻¹ yr⁻¹ (mean ± se) under best management practices, higher than 28.8 ± 0.5 t ha⁻¹ yr⁻¹ under standard estate practices. The bunch index, an indicator of the fruit production efficiency, increased by 12% under best management practices compared to standard estate practices. Partitioning of dry matter to the fronds decreased by 8% under best management practices, compared to standard estate practices. The positive effect of best management practices on the annual production of total aboveground dry matter was stronger in the plantation site with higher annual rainfall. These results are useful for optimizing management practices to improve sustainable intensification of oil palm.     

Spatiotemporal dynamics of plant diversity in response to farmers’ evolved settlements in Shanghai

The expansion of the Shanghai metropolitan region has caused a substantial amount of farmland to become urbanized. Most farmers have lost their land and have been relocated from villages to new collective settlements, resulting in dramatic changes in the landscape pattern. This study explores the effects of this transformation on the spatiotemporal dynamics of plant diversity. We randomly sampled 22 plots comprising 294 subplots within two crossed transects that pass through 5 traditional villages and 17 new settlements. The results show that resettlement has exerted significant effects on plant species diversity, both temporally and spatially. Temporally, the Gleason index (GI) of total species over time could be ordered as 1990s > 2000s > 1980s, while Shannon’s diversity index (SHDI) was ordered as 2000s > 1990s > 1980s. Spatially, the GI of total species decreased from the urban center to the exurbs or from the inside to the outside of the built-up areas. SHDI was highest in suburbs or ecotones. Furthermore, the GI of total species had significant correlations with those of indigenous species, exotic species, and planted species (r > 0.90, p < 0.01) as well as with the region and location of settlement (r < −0.48, p < 0.01). Both indigenous and exotic species had significant positive correlations with total species richness at 0.01 levels. Generally, compared with traditional settlements, new settlements displayed greater richness and diversity of plant species, primarily because of the exotic species present in new settlements. The farmers’ socio-economic status was found to be the primary cause of differences in species richness. To protect indigenous and wild species, it is necessary to take into account local knowledge in villages to encourage Chinese farmers to participate actively in community greening. A bridge should be built between traditional villages and modern settlements and between the past and future for farmers.     

从无梁楼盖到植物景观——探求植物的空间设计

以建筑的空间概念指导室外植物种植,并从宏观的空间概念、微观的空间特质以及空间的变化等方面对植物塑造空间的手法进行了探讨。