Variation in seed production among years and among individuals in 11 broadleaf tree species in northern Japan

Seed production is the most problematic part of tree regeneration and is the least amenable to control by silvicultural management. Understanding variability in seed production among years and among trees will allow better planning of seed collection for seedling production and natural regeneration. We estimated the extent of variability in seed production among years and within years among individual trees. Specifically, we measured individual annual seed production in 11 woody species in Hokkaido, northern Japan. We analyzed the coefficient of variation (CV) of seed production among years and among individual trees. We used population- and individual-based CVs (CV_pt and ) to estimate the variability in seed production among individual trees. Alnus hirsuta, in which these CVs among trees were maximal, will require further analyses of the spatial patterns of seed production among individual trees. Additionally, we used population- and individual-based CVs (CV_py and ) to estimate the variability in seed production among years. The was statistically higher than in 2 of the 11 species: Betula maximowicziana and Sorbus alnifolia. Activities for the regeneration of these species should regard the annual variation in seed production as more important than individual variation. For the nine species in which was similar to even if seed production by specific trees was not sufficient for regeneration in a particular year, other trees or stands often had high seed production in that year. We discuss the relative importance of annual and individual variability in determining efficient methods for artificial and natural regeneration of these woody plant species.     

Comparing an individual tree growth model for <Emphasis Type="Italic">Pinus halepensis</Emphasis> Mill. in the Spanish region of Murcia with yield tables gained from the same area

To support forest management decisions on converting stands from even-aged to uneven-aged management, tree models are needed that can simulate both options. Therefore, an individual tree model for Pinus halepensis Mill. is compared with the respective yield table. The individual tree model is built from data of two Spanish forest inventories in this province and evaluated with published yield tables, which have been built from permanent observational plots. The individual tree model consists of a basal area increment model and a height increment model, both based on two measurements of about 4,000 trees from single species stands of Aleppo pine. The R2 values of 0.362 and 0.107 for the basal area increment model and the height increment model, respectively, are within the range of other published models of this type. Comparing the model with the yield tables for different site indices, we find that our model matches the yield table well. Only in higher ages where the database for the yield table was poor, our model indicates higher basal area growth rates than the yield table.     

适于FVS的杉木单木模型构建

以福建省将乐国有林场杉木(Cunninghamia lanceolata)人工林标准地和解析木数据为依托,使用R语言,构建杉木单木胸径-树高模型、冠幅模型、胸径生长量模型(大树、小树)、树高生长量方程(大树)以及材积模型,并计算树皮因子。通过赤池信息准则(AIC)、贝叶斯信息准则(BIC)和对数似然值,结合R2值选择最优模型,并对所建模型进行精度检验。结果表明:各模型的预估精度最高的为树皮因子模型,精度达到99.01%,预估精度最低的模型为直径生长量模型,精度为83.54%,其余模型精度均达到95%以上;经t检验,所有模型估计值与实际值差异不显著,模型均可用于森林植被模拟系统。     

披针叶黄华茎叶性状对不同草地管理措施的响应及其生长关系研究

以青藏高原东缘草地典型毒杂草披针叶黄华(Thermopsis lanceolata)为研究对象,通过设置放牧、围封和综合措施(围封+施肥+划破+补播)3种不同的处理,比较披针叶黄华茎叶性状对不同草地管理措施的响应,茎与叶片间的生长关系及其生态适应性。结果表明:综合措施显著降低了披针叶黄华的叶片性状指标;与综合措施相比,放牧显著增加了每株植物茎干重(P<0.05);不同管理措施处理下披针叶黄华叶长、叶宽与叶面积之间,比叶重与茎干重之间均呈简单的异速生长关系,总叶干重与茎干重之间呈等速生长关系,不同的草地管理措施能够通过影响生长曲线的斜率从而影响二者之间的生长关系。围封对退化草地上披针叶黄华茎和叶片的生长抑制效果并不理想,因此需要同时结合施肥、划破、补播等综合管理措施才能使其得到有效的防控。     

论茶叶品牌个性的塑造

本文从品牌及品牌个性的基本含义出发,通过对茶叶企业品牌建设的某些实证研究,从茶叶品牌个性化的定位、产品、包装、服务、传播、促销等方面,探讨了茶叶品牌个性的塑造。     

集成配套技术对肉牛生产能力的促进作用调查

[目的]为了综合评价支撑平凉牛产业发展的集成配套技术应用效果。[方法]采取随机跟踪调查和现场测定的方法,对生长发育跟踪调查和肉用性能测定,进行比较分析。[结果]平凉红牛各月龄体重均提高10%以上;10-24月龄日增重达663.1 g,提高10.55%;胴体重、净肉重分别提高16.16%和13.73%;屠宰率、净肉率分别提高2.52和1.17个百分点;高档肉块重达23.00 kg,增加2.98 kg,可增加经济效益357.6元。[结论]通过普及应用集成配套技术,饲养的肉牛生长发育和肉用性能明显改善,肉牛个体生产能力提高10%以上,经济效益显著增加。     

干旱条件下冬小麦不同尺度水分利用效率及其之间的关系

为探讨小麦叶片、单株和群体尺度水分利用效率(分别用WUE_l、WUE_p和WUE_f表示)之间的相关性,以供体亲本京411和轮回亲本晋麦47及其34个近等基因系为材料,利用防雨棚和渗漏池开展模拟干旱试验,鉴定比较材料之间灌浆前期的WUE_l和全生育期的WUE_p,同时监测全生育期群体耗水量,测定籽粒产量,计算WUE_f,进而分析3个不同尺度水分利用效率之间的相关关系。结果表明,34个近等基因系及其父母本之间,WUE_l与WUE_p均存在显著差异,但是大部分近等基因系及其亲本之间产量没有显著差异,群体总耗水量及WUE_f存在极显著差异。经相关分析,WUE_l与WUE_p之间存在极显著正相关关系,R2达0.732 5,而WUE_l和WUE_p与WUE_f之间相关性均很低,R2分别为0.005 3和0.000 4。在干旱条件下,WUE_l可以作为WUE_p的鉴定评价指标,而WUE_l和WUE_p均不能作为WUE_f的鉴定指标。     

我国荷斯坦种公牛个体识别和亲子鉴定DNA数据库的建立

为了构建我国荷斯坦种公牛个体及亲子鉴定DNA数据库,本研究从联合国粮农组织(FAO)和国际动物遗传学会(ISAG)推荐的具有高度多态性的微卫星标记中选取11个常染色体微卫星标记(BM1824、BM2113、ETH、ETH10、ETH225、INRA023、SPS115、TGLA53、TGLA122、TGLA 126和TGLA227)以及4个自逸的Y染色体微卫星标记(MAF45、MCM158、UNM0108和UMN0929),采用荧光引物PCR和ABI3130遗传分析仪,对2 150头荷斯坦种公牛(Bos taurus)个体基因型进行了检测,并探讨其用于牛个体识别和亲子鉴定的可行性.研究结果表明:15个微卫星标记平均杂合度为0.766,平均多态信息含量为0.738,其中MCM158标记平均多态信息含量最高为0.866,SPS115标记最低为0.588,均属于高多态性标记.15个标记累积个体识别能力为99.99％,累积非父排除率达到99.99％,随机个体一致性概率为1.62×10-17.研究结果表明上述15个微卫星标记进行个体识别和亲子鉴定的效力与可靠性均很高,同时初步建立了荷斯坦种公牛DNA数据库.从而使个体识别和亲子鉴定程序标准化、统一化和简便化.     

不同密度条件下3种类型谷子品种产量及其构成要素变化特征研究

以群体个体并重夺高产型谷子新品种"冀谷26"和靠个体夺高产的单秆大穗型品种"泥里拽"、"聊农4号",靠群体夺高产的密植型品种"豫谷5号"、"冀谷14"为材料,试验研究了不同密度条件下谷子产量及其构成要素的变化。结果表明:靠个体夺高产的单秆大穗型品种谷子产量及其构成要素成穗率、单穗重、穗粒重、结实性均对密度反应敏感;靠群体夺高产的密植型品种对密度反应表现为产量敏感,单穗重、穗粒重比较敏感,成穗率、出谷率不敏感;群体个体并重夺高产品种表现为产量对密度反应不敏感,成穗率、出谷率比较敏感,单穗重、穗粒重敏感;3种类型品种单位面积穗数对密度反应都很敏感。在最适宜密度下群体个体并重夺高产型品种"冀谷26"产量水平明显高于另外两个类型品种,说明群体个体并重夺高产品种自身调节能力较强,丰产性、稳产性突出,代表今后育种的方向。     

农民工个体特征与欠薪问题的实证分析——以浙江省为例

在对浙江省7市农民工进行抽样调查的基础上,运用logit模型进行了回归分析。结果表明:文化程度、工资水平、地域来源与欠薪事件发生的概率呈显著负相关,即文化素质和月工资水平越低的农民工越可能被欠薪,外地农民工更可能被欠薪;并提出了相关政策建议。