加强河北省植保体系建设提升农业有害生物防控能力

分析了河北省植保体系建设的现状,阐述了现阶段河北省植保体系建设面临的新问题,并针对性地提出了建议和对策,可为今后的工作提供借鉴和参考。     

佳木斯城市绿地群落不同层次间种类多样性比较

应用物种丰富度指数(S)、Shannon-wiener多样性指数(H)、Simpson多样性指数(D)和均匀度指数(E)对佳木斯市9处典型绿地植物群落特征进行研究。结果表明:81个样地共记录乔木25种、灌木36种、草本108种。多样性分析表明:物种丰富度指数(S)为:草本层>灌木层>乔木层;而均匀度指数(J)又表现相反,为乔木层>灌木层>草本层;Shannon-wiener多样性指数(H)和Simpson多样性指数(D)表现一致,均为草本层>乔木层>灌木层。同时对佳木斯市绿地系统构建提出建议。     

植物残体分解过程中微生物群落变化影响因素研究进展

植物残体是土壤有机质的重要来源,研究分解植物残体的微生物群落结构及其演替规律日益受到重视。本文综述了影响植物残体分解过程中微生物群落结构和功能变化的3个主要因素:植物残体的性质、土壤和气候环境因素、农艺措施,这些因素通过影响微生物本身的活性和植物残体分解过程中化学组成的变化从而导致微生物群落的变化,同时植物残体腐解过程中微生物群落存在明显的演替现象。以上因素的影响并不是孤立的,而是相互联系和制约的。未来针对野外田间条件下植物残体的分解过程,仍需深入研究关键微生物群落的演替规律以及不同影响因素的交互作用机制。     

垄作栽培对小麦植株形态和产量性状的影响

为了明确不同栽培方式对小麦生长发育的影响,采用比较研究的方法,研究了传统平作和垄作对小麦植株形态和经济性状的影响。结果表明,与传统平作麦田相比,垄作小麦旗叶和倒二叶变小,而倒四和倒五叶变大,有利于构建“松塔型”的理想株型;灌浆中期垄作小麦各叶位叶片干重高于传统平作小麦的相应叶位叶片,而收获前又低于传统平作小麦的相应叶位叶片;垄作小麦开花期茎秆的干重高于传统平作小麦,而收获前又低于传统平作小麦,表明垄作小麦的茎秆和叶片对籽粒的贡献大于传统平作小麦;垄作栽培使小麦各节间,尤其是基部节间缩短,株高降低,有利于提高小麦的抗倒伏能力;垄作栽培提高了小麦的经济系数和经济产量以及籽粒容重。与传统平作相比,小麦垄作栽培更有利于构建理想株型,更好地发挥群体功能,提高产量。     

小麦株型结构分析法与消光系数分布的基因型间差异

拟定了快速而无需破坏样本的“株型结构分析法”及其计算机程序。调查了小麦冠层结构与消光系数(K值)分布在21个基因型间和同一基因型的不同处理间的差异。对该方法所作的验证表明:采用该法调查结果和分层切片法与Ross法的结果基本一致。此法是可靠的。冠层结构与K值垂直分布在基因型间差异极显著;同一基因型不同密度之间仅达显著程度。K值是比较稳定的遗传性状,广义遗传力为76.9％。总K值对籽粒产量影响不大。由于长江下游地区辐射条件较差,高产群体表现出冠层重心较高,K值分布呈上层大、中层小的特点。说明该地区选育的品种上部叶水平角宜小(倾斜至水平),中部叶宜直立。讨论中提出了以株型结构分析法对K值分布作选样和培育高产品种的可能性。     

典型草原封育过程中植物凋落物的变化动态

以内蒙古巴林右旗退化草原为研究对象,采用直接收集的方法,研究各种围封条件下,退化草原在自然演替过程中土壤凋落物的变化动态。结果表明：典型草原在封育演替过程中,凋落物呈增加的趋势,以封育10年的凋落物量最高;凋落物的养分,不同年限之间均存在显著差异,其中碳素含量以封育1年的最高,封育10年的最低,氮素则是以封育4年的含量...     

Plant diversity of secondary forests in response to anthropogenic disturbance levels in montane regions of northeastern China

The effects of anthropogenic disturbances on forest structure and plant diversity of secondary forest ecosystems were evaluated based on the classification by site factors in the montane regions of northeastern China. Forty-five sample plots containing 720 sub-plots of overstory species (8 m × 8 m), 1,440 quadrats of understory species (2 m × 2 m), and 1,440 quadrats of herbaceous layer species (1 m × 1 m) were clustered into five groups (G1, G2, G3, G4 and G5) by site variables with Hierarchical Cluster Analysis. Meanwhile, the disturbance levels corresponding to the five groups were determined according to the factors influencing human disturbances (D0-G2, D1-G1, D2-G3, D3-G5, and D4-G4). Species diversities of overstory, understory, herbaceous layer and overall species were evaluated using species number, Margalef index, Pielou index, Shannon–Wiener index, and Simpson index; and β-diversities (Whittaker index, Cody index). Basal area of stands exhibited a decreasing trend along the disturbance level due to a gradual increase in the extraction of timber by the human disturbances. The indices of species diversity suggested that overstory and understory species were distributed evenly among the groups or disturbance levels. There were no absolutely dominant tree species in the secondary forest ecosystems. The differences in site factors and the current disturbance intensities were not intense enough to lead to loose changes in overstory and understory species. The species diversity indices exhibited the maximum values at D3 (G5) for herbaceous layer species; this may suggest that the current disturbance intensities were intense enough to lead the changes of herbaceous layer species. Three rare and endangered species (Juglans mandshurica, Fraxinus mandshurica and Acanthopanax senticosus) were found within the secondary forests. These rare and endangered species appeared in each clustered group or disturbance level, which suggested that the current disturbance intensity in the study area was not strong enough to influence the distribution of rare and endangered species. The current disturbances in the secondary forests may not lead to a decrease in stability and complexity of the overstory and understory species, but the higher disturbance level may be intense enough to change the habitat fitness for the herbaceous species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized authors.     

Correlation between earthworms and plant litter decomposition in a tropical wet forest of Puerto Rico

Earthworms are recognized to play an important role in the decomposition of organic materials. To test the use of earthworms as an indicator of plant litter decomposition, we examined the abundance and biomass of earthworms in relation to plant litter decomposition in a tropical wet forest of Puerto Rico. We collected earthworms at 0–0.1 m and 0.1–0.25 m soil depths from upland and riparian sites that represent the natural variation in soils and decomposition rates within the forest. Earthworms were hand-sorted and weighed for both fresh and dry biomass. Earthworms were dominated by the exotic endogeic species Pontoscolex corethrurus Müller; they were more abundant, and had higher biomasses in the upland than in riparian sites of the forest. Plant leaf litter decomposed faster in the upland than riparian sites. We found that earthworm abundance in the upper 0.1 m of the soil profile positively correlated with decomposition rate of plant leaf litter. Ground litter removal had no effect on the abundance or biomass of endogeic earthworms. Our data suggest that earthworms can be used to predict decomposition rates of plant litter in the tropical wet forest, and that the decomposition of aboveground plant litter has little influence on the abundance and biomass of endogeic earthworms.     

引入科研前沿对植物生理学教学方法的改进和效果分析

大学生普遍存在科研创新意识差、缺乏科研热情的现象.补充相关科研进展,将科研前沿引进课堂成为一种趋势,笔者对植物生理学光合作用这一章关于补充光合碳同化科研进展与否的教学实践结果进行对比分析,采用调查问卷的形式,围绕已讲授和未讲授光合碳同化适应性进化这一科研前沿进行调查,旨在实现学生对光合碳同化途径多元化发展进化的理解和深化,启发学生对固有知识的质疑和求解热情,达到提升科研兴趣和创新能力,实现精品课程培养满足国家和地方发展需要的高素质人才的目的.     

张家界市永定区气象灾害防御及为农服务的现状与对策建议

我国气象灾害及其衍生灾害发生频繁，对经济社会发展和人民群众生产生活产生严重影响。农村是气象工作最广阔的领域，气象灾害防御工作对农业农村发展影响深远。本文以张家界市永定区为例，重点描述了本地区主要的气象灾害类型，分析当阶段农村气象灾害的防御现状，并从政府、资金、队伍、科技、防御、科普等六个方面，提出了气象灾害防御能力建设及为农服务的具体措施与建议。