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141.
以健康黑松(Pinus thunbergii)幼苗为材料,用非伤害性刺激,如冷冻和伤害性刺激,如:烧伤、刺伤、化学伤害等引发了植物体内的波形的变化,研究表明,非伤害性刺激能在幼苗体内引起动作电波的传递,伤害性刺激除了能引起动作电波的传递外,还能引起较为复杂的变异电波的传递并对这种现象进行了讨论。图4参28。 相似文献
142.
Michael J. OBrien Kevin L. OHara Nadir Erbilgin David L. Wood 《Forest Ecology and Management》2007,240(1-3):178-185
Native Monterey pine (Pinus radiata D. Don) stands on the Monterey peninsula have been significantly modified by natural and anthropogenic disturbances. The exclusion of fire and the introduction of pitch canker (caused by Fusarium circinatum Nirenberg & O’Donnell) created a need for the examination of these changing ecosystems with respect to regeneration, especially as these stands reach mature ages. We established 210 plots on 35 transects distributed throughout five stands in order to describe the current stand structure and quantify the extent and condition of regeneration. The results indicated that Monterey pine seedling establishment varies throughout the peninsula depending on percent canopy cover, duff and litter depth, and percent shrub cover while seedling growth is influenced by percent shrub cover. Canopy cover was also found to inversely influence shrub cover. Our study highlights the importance of understory removal to increase Monterey pine regeneration and seedling growth as canopy cover decreases, especially in areas where coast live oak (Quercus agrifolia Nee) and poison-oak (Toxicodendron diversilobum E. Greene) are abundant. 相似文献
143.
土壤益生菌对盆栽马尾松苗生长的影响 总被引:1,自引:0,他引:1
将固氮菌、解磷菌、解钾菌按不同组合接种到盆栽的马尾松幼苗根部,结果表明:2号固氮菌 解磷菌组合处理的苗木高生长比对照增长11.6%;2号固氮菌处理的苗木地径生长比对照增长23.3%;两种固氮菌 解磷菌 解钾菌组合处理的苗木生物量分别比对照增长45.5%和48.8%。而土壤中的N、P、K元素的含量也发生了明显的变化,1号固氮菌则使土壤含氮量增加54.2%,其它处理均使土壤含氮量减少。可溶性磷增加20.0%~50.0%,可溶性钾增加144.4%~277.8%。 相似文献
144.
145.
营林技术措施控制松毛虫灾害的研究结果表明:营林技术措施对松毛虫灾害有明显的控制作用,直接影响了森林生态系统,包括对森林植物群落、森林小气候、昆虫及其它动物群落产生影响;并可使树木生理发生变化,诱发林木的抗虫性,从而达到控制马尾松毛虫灾害的目的。 相似文献
147.
Effects of forest floor planting and stock type on growth and root emergence of Pinus contorta seedlings in a cold northern cutblock 总被引:1,自引:0,他引:1
D. Bruce Campbell Steven Kiiskila Leanne J. Philip Janusz J. Zwiazek Melanie D. Jones 《New Forests》2006,32(2):145-162
A two-year field trial was conducted to determine the growth response, and root emergence pattern of interior lodgepole pine
(Pinus contorta Dougl. var. latifolia Engelm.) seedlings in response to container type and forest floor removal. Seedlings were grown in StyroblocksTM, CopperblocksTM, or AirBlocksTM, and were planted directly into the undisturbed forest floor or into manually prepared planting spots where the forest floor
had been scraped away to expose the mineral soil. Seedlings planted into scalped planting spots exhibited marginally but significantly
(7%) greater above-ground growth rates (seedling stem volume); whereas seedlings planted into the forest floor produced significantly
more (11%) new roots. There were no differences in above- or below-ground biomass. Seedlings grown in CopperblockTM containers produced a higher proportion of roots near the top of the plug when tested at lifting, however this pattern was
not observed in the field. Given that scalping is more costly than forest floor planting, and that the increased shoot growth
was relatively small, we recommend that forest floor planting be considered as an alternative to manual spot scalping for
sites, such as the site tested here: those with cold, but well-drained soils and where competition from other plants is not
a serious problem. 相似文献
148.
149.
Water relation parameters of bare-root seedlings of Chinese fir (Cunninghamia lanceolata Hook.)and Masson pine (Pinus massoniana Lamb.)were measured and changes of root growth potential as well as field survival rate of both species were studied after the bare-root seedlings were exposed in a sunny field condition.the results showed that masson pine had a lower osmotic potential(-2.07Mpa) at turgor loss point and at full turgor(-1.29Mpa),compared with Chinese fir(-1.80Mpa and -1.08Mpa respectively).The parameter Vp/Vo(63.27%) of Masson pine was higher than that of chinese fir (58.03%).This means that Masson pine has a stronger ability to tolerate desiccation,compared to Chinese fir according to analysis of above water relation parameters.Root growth potential and field survival rate decreased with prolonging duration of exposure.The field survival rate of both species was reduced to less than 40% after the seedling being exposed only two hours.Water potentials of -1.60 Mpa and -1.70 Mpa were suggested to be critical values for Chinese fir and Masson pine respectively in successful reforestation. 相似文献
150.
采用以空间代时间的径级标准木收获法,研究了从幼林到成熟林的5种不同林龄的林分生物量.结果表明:树木干物质是按一定比例分配到各器官,其比例与径阶大小无关,而与发育阶段有关.林分平均木及林分各器官生物量均随林龄增加而增加,平均木在18 22a生物量年增加速率最大,而林分是在12 18年生.树干生物量所占百分比(占48%以上)随林龄增加而增加,而枝、叶、皮刚好相反,18年生以前,根所占百分比随林龄增加而下降,此后趋于稳定.各器官所占百分比由大到小依次为:干、枝、根、皮、叶.8、12、18、22、30年生的林分乔木层生物量分别为:33.94、89.94、204.51、223.71、234.14t.hm-2,净生产力为:6.24、11.14、15.63、14.07、11.93t.hm-2.a-1.中龄前,生物量按径阶分布的规律与株数按径阶分配规律相似,多呈左偏态,此后呈右偏态,峰值比株数按径阶分布向右移动1 2个径阶.培育纸浆材林,在18年生前利用最佳. 相似文献