不同种子催芽方法对杜松育苗的影响

采用3种不同的方法对杜松种子进行催芽处理实验,结果表明:相比于混砂催芽方法和温、冷水交替浸种催芽法,采用热水浸种、变温催芽方法处理的种子,播种后出苗时间短,苗齐,其1年生幼苗高生长、地径以及壮苗数量都较高。在育苗上,热水浸种、变温催芽方法要好于其它两种方法。     

Growing common plantation tree species in Kenya for sale of carbon and wood supply: what is the best bet?

The introduction of carbon finance as an incentive in forestry farming has a potential of increasing the amount of carbon sequestered. However, this has created a daunting task among investors in forestry to optimise the joint production of wood and carbon sequestration. For instance, investors might find it profitable to give up some timber returns in exchange for carbon credits. This study evaluated expected income from growing Cupressus lusitanica Mill., Pinus patula Schiede ex Schltdl. & Cham., Eucalyptus saligna Sm. and Juniperus procera Hochst. ex Endl. for wood and/or the carbon market in central Kenya. The global average unit price of carbon and stumpage royalty were used to estimate expected returns from sale of carbon credits and wood, respectively. There were significant differences (p < 0.01) in the expected amount of income from sale of carbon and wood among the four species. Specifically, at economic rotation of 30 years with stand density of 532 trees ha^?1 P. patula and C. lusitanica yielded US$28 050 and US$23 650, respectively, from sale of carbon compared with US$59 000 and US$51 000, respectively, from sale of wood. This was twice the value investors receive from clear-felling as compared with sales from carbon. Similarly, at economic rotation of 33 years with stand density of 150 trees ha^?1, a forest investor in E. saligna would earn US$15 400 from sale of carbon compared with US$33 000 from sale of wood. Overall, the amount expected to be realised from sale of carbon was lower compared with that from sale of wood. This demonstrates that the price dynamics of carbon offsets in the voluntary and the compliance markets need to remain competitive and attractive for the forest owners to give up some timber returns in exchange for carbon income or to modify forest management regulation in order to increase carbon sequestration.     

晚松营养袋育苗造林试验初报

对晚松进行营养袋育苗和带袋造林试验结果表明，采用营养袋育苗并带袋上山造林，初植成活率和年终保存率均在９０％以上，造林后第２年高生长量在２０ｃｍ以上，１～２次分枝数多，抗干旱能力强，其优点明显大于裸根苗造林，该育苗造林技术宜在雨量充沛、气候湿润的低山丘陵地区和农田防护林工程中推广应用，这将对加速荒山绿化后的补植及改善农田防护林树种结构有一定作用。     

长宁竹海5种林分类型的水文效应评价

对长宁竹海的苦竹、毛竹、黄竹林,杉木林及白栎林5种林分类型的水文效应进行了研究。结果表明:林分中的草本植物植冠层的水分最大截留量是乔灌层植物的2.4倍。按种类以苔草最高,为6.34 g/g(干生物量);黄竹最小,为1.19 g/g。5种林分林地枯落物的现存量为4.33~14.87 t/hm2,其分解层的蓄水量高于末分解层,枯落物层最大蓄水总量为1.0~3.5 mm,依杉木林>白栎林>毛竹>苦竹>黄竹排序;土壤蓄水量以杉木林最大,白栎林次之,竹林最差;而土壤稳定渗透系数K10以竹林最大,杉木林次之,白栎林最小,表明竹林土壤抗水蚀能力强于杉木林和白栎林。     

杜松小孢子的发生和雄配子体的发育

利用常规石蜡制片技术,对杜松小孢子发生及雄配子体的发育过程进行观察.杜松的雄球花3月初开始分化.小孢子囊壁一般包括3层细胞:表皮、中层和绒毡层.造孢细胞在3月中旬形成,3月下旬形成小孢子母细胞,4月上旬开始减数分裂,4月中旬形成四分体,4月下旬小孢子从四分体释放出来.5月上旬开始散粉,成熟花粉粒为单核花粉粒.散粉后,胚珠内的花粉萌发出一短的花粉管后休眠,第2年4月份开始分裂形成管细胞、不育细胞和2个精子细胞.小孢子母细胞发育表现出不同步现象,部分小孢子母细胞在发育过程中退化,在小孢子囊内形成空腔.小孢子囊在小孢子叶基部远轴面和叶腋处都有发生,小孢子叶球为复合小孢子叶球.     

硬头黄竹花的形态与结构研究

[目的]研究硬头黄竹花(Bambusarigidd)的基本形态结构及胚胎发育规律,为其胚胎学积累原始资料,为育种工作打下基础。[方法]通过解剖与形态观察的方法,对硬头黄竹生殖器官、抱子发生及雌雄配子体的发育过程进行解剖观察。[结果]硬头黄竹小穗为假小穗,簇生,基部具潜伏芽,平均长度为3.75 cm,有3~7朵小花。小花内外稈各1片,浆片3枚,雌蕊1枚,雄蕊6枚。雌蕊为三分枝羽毛状柱头。子房长卵圆形,具明显纵向三棱。子房单室,侧膜胎座、倒生胚珠。正常发育的花粉粒为二细胞花粉,花药壁造抱细胞时期为四层药壁,花药成熟时只剩两层药壁。绒毡层为分泌型,花药成熟时,绒毡层完全退化。花药易见发育异常现象,形成不同的败育类型。[结论]硬头黄竹小穗基本结构发育正常,但花药发育后期会大量出现异常现象,这是导致硬头黄竹结实率低的主要原因。     

Status of cypress aphid on Cupressus lusitanica and Juniperus procera in protected and cultivated forests of South Wollo,Ethiopia

In Ethiopia,Cupressus lusitanica and Juniperus procera are important tree species.The incidence of the cypress aphid,Cinara cupressi,which has not been reported before on the exotic Cupressus lusitanica is becoming catastrophic.The appearance of the insect was reported for the first time in 2003 in Ethiopia.However,information is scarce on the status of this species in northeast Amhara state.The objectives of this study were to assess the extent of damage,abundance and status of the cypress aphid on C.lusitanica and J.procera in the protected and cultivated forests of South Wollo,Ethiopia.Results reveal that tree compositions of the three study areas differed.The dominant tree species were C.lucitanica(15–80%),Olea europaea(5–90%)and J.procera(14–70%).The cypress aphid showed significantly higher levels of infestation on C.lusitanica(35–90%)than on J.procera(1–16%).Moreover,there was higher C.lusitanica mortality(40–93%).In contrast,there was low infestation(1–16%)on J.procera and no mortality.The results reveal that the cypress aphid causes enormous losses of C.lusitanica.Therefore,it is recommended that insect surveillance be strengthened and the introduction bioagents be considered and integrated with other insecticides to minimize the degree of C.lusitanica infestation and loss.     

民族药材刺柏的粉末显微鉴定

[目的]研究刺柏茎枝粉末的显微特征。[方法]将刺柏茎枝粉末用浓度1%番红花红T染色,装片,树胶封片,用显微镜多次观察并拍摄,对刺柏茎枝粉末进行显微鉴别,并选用Image-Pro Plus 6软件对其显微组织进行测量。[结果]刺柏茎枝粉末的纤维纹孔明显,有交错的纹理,直径22～55μm,少有分隔纤维;晶纤维易见,含晶细胞2～5个,沿纤维方向排列,方晶长22～30μm;韧皮纤维两端狭长,胞腔明显,直径42～54μm;木纤维直径48～72μm,壁连珠状加厚,纹孔不明显;有的木栓细胞胞腔内含棕色物;孔纹管胞相邻细胞的具缘孔纹成对出现,纹孔明显,直径13～32μm;网纹管胞破裂,多个相连,纹孔排列整齐,孔径23～34μm。[结论]该方法研究了刺柏茎枝粉末的显微特征,可为刺柏的鉴别提供依据。     

彩色针叶树N、P、K施肥比例初探

[目的]探讨不同N、P、K施肥比例对彩色针叶树生长和干物质积累的影响。[方法]以从美国引进的‘金叶疏枝’欧洲刺柏为供试品种,栽培在珍珠岩+蛭石(3∶7)的基质中,采取喷施营养液的方式,以清水为对照(CK),研究不同N、P、K施肥比例对‘金叶疏枝’欧洲刺柏株高、冠幅、地径、高径比、单株干重、地上部分干重、地下部分干重和根冠比的影响。[结果]与对照CK相比,各处理都能够提高株高、地径、冠幅、高径比、单株干重、地上部分干重、地下部分干重及根冠比,但各处理影响程度有差异,处理⑤在0.05水平上显著促进‘金叶疏枝’欧洲刺柏的株高、冠幅、单株干重、地上部分干重和地下部分干重。[结论]合理的N、P、K施肥比例可促进‘金叶疏枝’欧洲刺柏的生长和干物质的积累。     

新疆圆柏叶挥发油化学成分变化的研究

采用水蒸气蒸馏法和气相色谱-质谱联用技术,对新疆圆柏(Sabina vulgaris Ant.)鲜叶和贮存1年的干燥叶中的挥发油化学成分进行检测,鲜叶中的成分鉴定了31种,干叶中的成分鉴定了23种,共有成分15种。与鲜叶比较,干叶中含量减少的成分是:2,7-二甲基-3-辛烯-5-炔(51.88%,15.29%,前者为鲜叶中的量,后者为干叶中的量,下同)、1-柠檬烯(1.65%,1.13%)、α-异松油烯(0.92%,0.58%)、3,7-二甲基-甲基酯-2,6-辛二烯酸(2.88%,0.50%)、α-长叶蒎烯(1.91%,1.46%)、α-雪松醇(12.69%,10.81%),含量增加的成分是:β-侧柏酮(1.01%,1.98%)、4-甲基-1-(1-甲基乙基)-3-环己烯-1-醇(0.22%,2.83%)、β-香茅醇(0.22%,10.83%)、乙酸香桧酯(4.37%,39.83%),新疆圆柏鲜叶和干叶中的挥发性成分及其含量差异甚大,但是特征成分种类基本一致,随着叶的干燥贮存时间的延长,其挥发性成分及其含量在逐渐减少。