A Miocene rodent nut cache in coastal dunes of the Lower Rhine Embayment, Germany

A fossil burrow system containing a food cache was discovered in coastal facies in the Lower Rhine Embayment near Cologne, Germany, in the lignite sequences of the Garzweiler open-pit mine. Because these sediments are of Burdigalian age (late Early Miocene), this cache appears to be the geologically oldest food cache to date. The burrow occurs in the Morken Sand beds (horizon 5D), and it is hypothesized here that it was excavated by a Miocene burrowing animal from the surface of a palaeosol into the underlying dune sand in an interdune area. Based on the morphology of the burrow system and the size of the galleries, the burrow was made by a rodent, most likely a large hamster (e.g. Lartetomys or Karydomys ) or, conceivably, a large ground squirrel. The chambers, and sometimes the galleries, of the burrow were filled with a monospecific cache of considerable size, estimated here as a minimum of 1800 nuts, although it was probably much larger. This food cache, a larder hoard, consisted of the three-dimensionally preserved nuts of Castanopsis pyramidata (Fagaceae). Because many extant rodents are long-term larder hoarders in regions experiencing seasonal food shortages (e.g. those with cold winter conditions or a dry season), the occurrence of this type of food cache in the Early Miocene implies an acute or chronic scarcity of food resources which, in turn, may be linked to either seasonal cycles in food availability in the backbeach environment or, plausibly, may possibly foretell the onset of climatic seasonality in the entire region.     

栲树种群生态位动态研究

用Levins生态位宽度及重叠、Feinsing等生态位宽度和Petraitis生态位重叠计测方法,处理缙云山森林群落演替系列取样,分析栲树种群的生态位特征及动态.结果表明,栲树种群为缙云山森林群落演替顶极群落常绿阔叶林的优势种群,其生态位宽度随群落演替过程基本呈增长趋势,而资源利用程度却呈“∧”形;对于栲树种群和缙云山森林群落其它14个优势种群间在所有5类群落中的生态位重叠,仅栲树种群与典型针阔混交林中的小叶栲、光叶灰木、川灰木、薯豆、白毛新木姜子、广东山胡椒、大头茶、虎皮楠、杉木、马尾松种群上和针叶林中小叶栲、光叶灰木、杉木种群上,表现出显著完全特定重叠.     

马尾松红锥混交林现状分析与评价

本文根据广西六万林场马尾松、红锥混交林的调查结果,分析了松、锥混交林各树种的胸径、树高和材积的生长现状;土壤的理化特性;松锥混交林营造技术措施。并对该场松锥混交林存在的问题,初步探讨了松锥混交林合理的种间关系和营林的主要技术措施。     

浙江古田山自然保护区甜槠群落特征研究

甜槠林是古田山自然保护区常绿阔叶林主要类型之一。通过对甜槠群落特征进行分析和研究 ,结果表明 :甜槠群落中 ,甜槠的优势明显 ,呈单优势群落。群落外貌以小型和中型叶、单叶、非全缘、革质及草质的小、中高位芽植物组成为特征。群落垂直结构复杂 ,可分为乔木层、灌木层和草本层 ,并有一定数量的层间植物。乔木层物种多样性指数偏低 ,垂直结构各层次间物种多样性大小依次为灌木层 >乔木层 >草本层。     

海南锥栗属新植物

1.五指山锥　别名 :山白锥 (五指山 )　新种　图版 - ACastanopsis wuzhishangensis　 G.A.Fu sp.nov.Species affinis Castanopsi carlesii( Hemsl.) Hayatavar.spinulosa,a qua folia crasoribus et duroribus dif-ferf.Etiam affinis C.Echinocarpae Miq.var.senin-udae,se     

珍稀濒危植物青钩栲种群数量特征研究

提出自适应种群增长新模型Ｓ＝ｅｘｐ（ａｌｎ＾２（１＋ｃｅ＾－ｒｔ）＋βｌｎ（１＋ｃｅ＾－ｅｔ）＋γ）,该模型包融了Ｌｏｇｉｓｔｉｃ模型、Ｓｍｉｔｈ模型、Ｇｏｍｐｅｒｔｚ模型、崔－Ｌａｗｓｏｎ模型、张－Ｌｏｇｉｓｔｉｃ模型和刘－Ｌｏｇｉｓｔｉｃ模型,运用遗传算法适应新模型进行参数估计,拟合青钩栲种群增长规律比其它种群增长模型更符合青钩栲群种的实际增长趋势,说明新模型具有一定的实用价值。     

三峡库区世坪常绿阔叶林群落特征

重庆丰都世坪森林公园的常绿阔叶林是长江三峡库区低海拔区残存的较典型常绿阔叶林,林内植物种类丰富。1hm2固定样地的调查表明,群落内共有维管束植物195种,隶属73科142属,植物的科属组成丰富。群落内区系地理成分复杂,与热带植物区系关系较密切,但温带区系成分也占有相当大的比重。群落的外貌主要由中小型革质、单叶为主的常绿高位芽植物所决定。群落成层现象明显,可分为乔木层、灌木层和草本层3个层次,层间植物丰富。总之,无论区系组成还是群落外貌和结构均体现了中亚热带北缘常绿阔叶林的特征。世坪森林公园的常绿阔叶林是三峡库区宝贵的植物基因库,希望有关部门尽快在此设立常绿阔叶林保护区,以保护本地区植被恢复的种质资源。     

不同胁迫处理对刺栲叶片叶绿素a荧光的影响

探讨了光强、温度和水分胁迫对刺栲(Castanopsis hystrix)体叶片叶绿素a荧光特征的影响,由此了解它的基本生物学特性。结果表明:(1)强光(1 300μmol.m-2.s-1左右)未胁迫时下降6.1%,表现轻微光抑制;(2)黑暗下低温(4℃,72 h)处理后电子传递速率下降较少(21.1%),初始荧光Fo保持稳定;与25℃对照相比,Fv/Fo和Fv/Fm无显著变化,表明黑暗下零上低温对PSⅡ潜在活性及光化学效率影响较小;(3)高温(40℃)胁迫显著影响了PSⅡ反应中心活性,ETR,Fv/Fm和Fv/Fo下降在处理2 h后达到极显著水平(p<0.01),Fo上升在处理4 h后也达到显著水平(p<0.05);(4)PEG诱导的水分胁迫严重影响了其光合机构活性,表现在无论与处理前比较、还是与耐旱种降真香(Acronychia pedunculata)的比较,其Fo上升和Fv/Fm、Fv/Fo下降都达到显著水平,表明其不耐干旱。     

Photosynthetic induction in leaves of co-occurring <Emphasis Type="Italic">Fagus lucida</Emphasis> and <Emphasis Type="Italic">Castanopsis lamontii</Emphasis> saplings grown in contrasting light environments

Photosynthetic induction times and photoinhibition in relation to simulated sunflecks (sudden increase of irradiance from 20 to 1,500 μmol m⁻² s⁻¹) were examined in leaves of co-occurring Fagus lucida (a deciduous tree) and Castanopsis lamontii (an evergreen tree) saplings grown either in a beech forest understory or in an adjacent open site during a late rainy season. Two hypotheses were tested: (1) understory leaves would display faster photosynthetic induction times and greater photoinhibition than open-grown leaves; and (2) evergreen species would have slower photosynthetic induction times and lighter photoinhibition than deciduous species. Times to reach 90% of maximal CO₂ assimilation rate (t _90%A ) and stomatal conductance did not differ between species, but showed faster by 3–5 min in open-grown leaves than understory leaves due to higher initial stomatal conductance (g _{s initial}) and induction state 1 min into simulated sunflecks (IS_1min) in the former. Our analysis across the published data on photosynthetic induction of 48 broad-leaved woody species again revealed the negative correlations between t _90%A and either g _{s initial} or IS_1min, and the similarity of t _90%A and between evergreen and deciduous species. Measurements of maximum PSII photochemical efficiency (F _v/F _m) indicated that photoinhibition occurred in saplings in any of the growth habitats during sunfleck-induced photosynthetic induction. Despite no interspecific differences in the degree of photoinhibition, understory leaves of both species suffered heavier photoinhibition than open-grown leaves, as indicated by a stronger decrease of F _v/F _m in the former. Dynamic changes in the quantum yields of PSII photochemistry and ΔpH- and xanthophyll-regulated thermal dissipation and adjustments in the partitioning of electron flow between assimilative and non-assimilative processes were functional to resist photoinhibition. However, such photoinhibition, together with stomatal and biochemical limitations, would decrease carbon gain during simulated sunflecks, particularly in understory leaves.     

四种栲属植物微卫星标记在钩栲中的通用性检测

钩栲（Castanopsis tibetana）是中国亚热带常绿阔叶林具有代表性的建群种之一,由于生境片段化的影响,其遗传多样性和进化潜力受到严重威胁。为研究钩栲遗传多样性及群体遗传特征,本研究从来自中华栲（Castanopsis chinensis）、苦槠栲（C．sclerophylla）、尖叶栲（C．cuspidata）、日本栲（C．sieboldii）4种栲属植物的51个微卫星位点中,筛选出35个在钩栲中具有稳定PCR扩增的位点：采用4个钩栲群体24个个体进行检测,发现11个位点具有较低的多态性,其中等位基因数目（N。）为2。7,平均4．5：观测杂合度（Ho）为0．083～0．917,平均0．505;预期杂合度（HE）为0．236～0．667,平均0．471。研究结果对钩栲遗传多样性研究和保护具有重要作用。