Logging Impacts in Tropical Lowland Humid Forest on Tree Species Diversity and Environmental Conservation

This study assessed the effects of exploitations in natural forest ecosystems on tree species diversity and environmental conservation. This was achieved by comparing tree species diversity and yield in an unlogged forest (Strict Nature Reserve) and a forest reserve where active logging is in progress in Ondo State, Nigeria. Eight plots (20 m × 20 m) were assessed in each site using systematic sampling techniques. All living trees with dbh >10 cm were identified, categorized into families with their diameter at breast height (dbh) measured in each plot. Shannon-Weiner and species evenness indices were used to assess and compare tree species diversity and abundance. The results show that the tropical humid forest is very rich in tree species, as a total of 54 different tropical hardwood species from 23 families were encountered in both forest types. There were 46 species distributed among 21 families in the unlogged forest and 24 species in 14 families in the logged forest. Shannon-Weiner diversity index of 3.16 and 3.03 and evenness index of .83 and .81 were also obtained for the unlogged and logged forest, respectively. Every variable computed had a higher value in the unlogged forest relative to the logged forest. In the unlogged forest, the species with the highest number of occurrence was Mansonia altissima A. Chev. (80 stems/ha). Caesalpinoidae and Sterculiaceae families had the highest number of species (6). In the logged forest, Triplochiton scleroxylon K. Schum. (18 stems/ha) had the highest frequency and Caesalpinoidae family has the highest number of species (4). The study concludes that exploitation has affected species diversity in the ecosystem and subsequently, the roles of trees in environmental conservation are affected.     

麻栎胚根切除防穿袋育苗技术的研究与应用

麻栎是云南滇中地区的本土树种。1999年以来,在云南牟定县启动实施的中德合作造林项目中采取云南松与麻栎混交的主要造林模式,在麻栎育苗过程中,采用普通的塑料袋育苗技术存在出圃前出现主根严重穿袋现象,造成了苗木出圃率和移植成活率较低。为此,开展了麻栎胚根切除技术及育苗用土施肥2种措施,在防止育苗穿袋方面取得了成功,并在中德合作云南二期造林项目中推广和应用3193hm^2,采用麻栎胚根切除技术育苗,苗木合格率提高了25．70％,造林成活率提高了32％,取得了显著的经济和社会效益。     

Herbage intake,milk production and sward utilization of dairy cows grazing grass/white clover swards at low,medium and high allowances

Abstract

Herbage intake (HI), milk production and sward utilization of Norwegian Red Cattle dairy cows in mid-lactation, rotationally grazing grass/white clover swards at low, medium and high allowances (HA), were examined in three experiments (I, II and III). The daily target allowances per cow were 18 and 36 kg DM in Experiment I and 12, 18, and 24 kg DM in Experiments II and III. The cows were grazing in groups of seven (Experiments II and III) to ten (I) individuals. The proportions of white clover in the swards averaged 12%, 40% and 46% in Experiments I, II and III, respectively. In addition to pasture, the cows were fed concentrate mixtures in varying amounts (0–6.8 kg) with the highest amounts offered to the highest yielding cows. HI was estimated using the n-alkane technique. No effect of HA on HI was obtained in Experiment I. In Experiment II, and for II and III combined, there was a significant positive effect of HA on HI. The average increase in HI was 0.24 kg DM per extra kg DM on offer. The utilization of the sward (measured at 3 cm above ground level) decreased from 72% at the lowest HA to 51% at the highest HA in Experiment II and III. HA did not affect milk yield or milk composition significantly (P>0.05).     

5%桉油精可溶液剂防治杨小舟蛾幼虫效果的研究

进行了不同浓度5%桉油精可溶液剂对杨小舟蛾防治效果的田间试验,以及2000倍的烟碱·苦参碱进行田间对比试验,结果表明:5%桉油精可溶液剂1500倍对杨小舟蛾防治效果较好,喷药后5d防效为100%。试验结果为今后5%桉油精可溶液剂防治杨小舟蛾的合理农药配比浓度提供科学依据。     

废旧手机资源化回收利用初探

分析了废旧手机所蕴含的经济价值,简述了当前废弃手机回收处理的一些方法、工艺技术。重点探讨了废旧手机中金属的回收利用技术,并对未来我国废旧手机的回收和资源化利用提出了一些合理性意见,从而实现资源的综合利用。     

Efficiencies of Chemical Techniques for Rice Grain Freshness Analysis

Two chemical methods which are commonly used for rice grain freshness determination were investigated for their efficiencies.Method 1 is made of bromothymol blue indicator,and the principle is based on indicator’s color which is changed in according to pH of the stored rice grains.Method 2 is based on peroxidase activity which deteriorates during storage of rice grains.Both methods were used for determination of fresh-aged rice index of six Thai-rice cultivars,four from non-waxy rice cultivars (KDML 105,Chai Nat 1,Chai Nat 2 and Phitsanulok 2) and two from waxy rice cultivars (San-pah-tawng and RD6).Rice samples were kept in the forms of paddy and polished rice.Fresh-aged rice indices were determined using both methods every two weeks over the storage period of 24 weeks (six months).It was found that both methods were capable of detecting fresh-aged rice indices.The color of chemical solutions changed with regards to the age of rice grains and it could be detected spectrophotometrically.Rice grains which have been kept as paddy provided more consistent results.Method 1 is recommended for industrial application as it is simple,efficient and inexpensive.     

马铃薯纺锤块茎类病毒检测技术比较与选择

马铃薯纺锤块茎类病毒(PSTVd)是威胁我国马铃薯生产的重要病害之一,目前有多种技术可应用于PSTVd的检测,如生物学方法、电子显微镜技术、往返聚丙烯酰胺凝胶电泳(R-PAGE)、核酸斑点杂交(NASH)、RT-PCR和FQ RT-PCR。这些方法各有利弊,互相补充,构成了PSTVd的检测技术体系。日常工作中,应根据自身条件及目的等科学地选择适宜的检测技术,确保脱毒种薯/种苗的质量。     

水稻栽培技术措施对稻米品质的影响

稻米品质与水稻栽培技术措施是否得当有着直接关系,稻米已成为人们生活中的主食,其质量关系到人们的生活质量,因此必须解决水稻栽培技术对稻米品质的影响。研究表明,早育苗早插秧可提高精米率,降低整精米率而提高糊化温度、粗蛋白质、使胶稠度变硬。晚育苗,晚插秧,则稻米品质结果则相反。插秧方式过密、株行距过小,会导致糙米率、精米率、整精米率下降,垩白率增加,直链淀粉含量及胶稠度有所提高,蛋白质含量下降而米质变差。科学施肥既能提高稻米外观品质,又能改善食味品质,防治杂草及防治病虫害是提高稻米品质的重要技术措施,灌溉水质关系到稻米品质的优劣,收获时期与方法、仓储技术都会对稻米品质产生一定的影响。因此水稻栽培技术对稻米品质的影响不容忽视。本文从水稻育苗、移栽、施肥、除草、防治病虫、灌溉、收获、仓储等技术措施,对稻米品质影响加以简述,仅供生产优质稻米参考。     

分子印迹技术及其在天然产物固相萃取中的应用

文中综述了分子印迹技术(MIT)的原理,分子印迹聚合物(MIPs)的制备方法,以及在天然产物固相萃取中的研究现状。     

明菊1号选育·特征特性·高产栽培技术

[目的]介绍高产、高糖苷含量的甜叶菊(Stevia rebaudiana Bertoni)新品种明菊1号。[方法]对高糖苷含量甜叶菊新品种明菊1号的选育过程、特征特性、产量表现及栽培技术要点进行综述。[结果]2011年通过安徽省非主要农作物品种鉴定登记委员会审定,命名为明菊1号。在安徽明光等地种植,平均产量约为3 270 kg/hm2,比守田2号(CK)增产11.5%。总甜菊糖苷含量占干叶重11%以上,RA3含量超过70%。[结论]该研究可为明菊1号的推广应用提供理论论据。