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421.
资源冷杉是国家一级保护植物、中国特有种,呈极度濒危状态。采用样地调查法对江西南风面无人为干扰的原始森林资源冷杉所在群落特征进行研究,结果表明:调查群落共有维管植物68种,隶属34科47属; 含属种较多的科有杜鹃花科(2属8种)、山茶科(4属6种)、冬青科(1属6种)、樟科(2属5种)、壳斗科(3属4种),占总种数的42.0%; 热带性质的属共占非世界属总数的46.5%,温带性质的属共占48.8%,中国特有分布的属占4.7%; 古老的残遗属和亚热带山地的表征属占有极大的优势。群落乔木层可分为4层,第一亚层和第二亚层的优势种有资源冷杉、南方铁杉、南方红豆杉和多脉青冈等。调查的资源冷杉种群目前处于相对稳定的状态,所在群落是该地区的顶极群落。 相似文献
422.
We have adapted a procedure for the isolation of genomic DNA from needles of silver fir (Abies alba) to meet the requirements for large-scale analysis of the population genetics of forest trees. Our modifications permit the
entire procedure to be carried out in Eppendorf tubes, which greatly minimizes time, plant material, and the amounts of chemicals.
DNA is recovered with a mean efficiency of 80 μg/g needles, is suitable for restriction by the common endonucleases, and serves
as a substrate for PCR. 相似文献
423.
新型树种猫儿屎的繁殖 总被引:1,自引:0,他引:1
猫儿屎(Decaisnea fargesii Franch.)是木通科猫儿屎属的一种野生植物资源,用途广泛,值得开发利用。采用扦插繁殖和种子播种繁殖,提高苗木产量和苗木种植成活率。 相似文献
424.
425.
426.
城市近自然园林的理论基础与营建方法 总被引:11,自引:0,他引:11
近自然园林是一种可持续发展的园林规划和建设理念,是生态园林建设的模式之一,也是实现节约型园林的主要措施和未来园林的发展方向。本文在分析我国园林建设问题的基础上,阐述了近自然园林的概念、内涵与理论基础,提出了近自然园林营建的基本原则,详细总结了近自然园林的设计、营造和管护方法,并探讨了当前近自然园林建设中存在的问题与措施,为强化近自然园林理念、促进我国城市近自然园林的研究与建设提供了依据。 相似文献
427.
Larval diapause of Monochamus urussovi and photoperiodic effects on larval development in tree bolts
To determine the larval diapause and the effect of photoperiod on development in Monochamus urussovi (Coleoptera: Cerambycidae), larvae were reared on Abies sachalinensis and Picea jezoensis logs and bolts. Larvae stopped developing in the final instar at 25°C and 16L : 8D (16 h light and 8 h dark) whereas an exposure to 5°C in the dark (134 days) following acclimation at 12°C under natural daylength led to adult emergence. When larvae were reared under 8L : 16D or 16L : 8D at 25°C with an intervening period of chilling at 5°C in the dark (112 days), a photoperiod of 8L : 16D induced a shorter time required for adult emergence after being returned to 25°C, and smaller adult body size than 16L : 8D. 相似文献
428.
Francisca Alba‐Sánchez José A. López‐Sáez Blas Benito‐de Pando Juan C. Linares Diego Nieto‐Lugilde Lourdes López‐Merino 《Diversity & distributions》2010,16(2):214-228
Aim Quaternary palaeopalynological records collected throughout the Iberian Peninsula and species distribution models (SDMs) were integrated to gain a better understanding of the historical biogeography of the Iberian Abies species (i.e. Abies pinsapo and Abies alba). We hypothesize that SDMs and Abies palaeorecords are closely correlated, assuming a certain stasis in climatic and topographic ecological niche dimensions. In addition, the modelling results were used to assign the fossil records to A. alba or A. pinsapo, to identify environmental variables affecting their distribution, and to evaluate the ecological segregation between the two taxa. Location The Iberian Peninsula. Methods For the estimation of past Abies distributions, a hindcasting process was used. Abies pinsapo and A. alba were modelled individually, first calibrating the model for their current distributions in relation to the present climate, and then projecting it into the past—the last glacial maximum (LGM) and the Middle Holocene periods—in relation to palaeoclimate simulations. The resulting models were compared with Iberian‐wide fossil pollen records to detect areas of overlap. Results The overlap observed between past Abies refugia—inferred from fossil pollen records—and the SDMs helped to construct the Quaternary distribution of the Iberian Abies species. SDMs yielded two well‐differentiated potential distributions: A. pinsapo throughout the Baetic mountain Range and A. alba along the Pyrenees and Cantabrian Range. These results propose that the two taxa remained isolated throughout the Quaternary, indicating a significant geographical and ecological segregation. In addition, no significant differences were detected comparing the three projections (present‐day, Mid‐Holocene and LGM), suggesting a relative climate stasis in the refuge areas during the Quaternary. Main conclusions Our results confirm that SDM projections can provide a useful complement to palaeoecological studies, offering a less subjective and spatially explicit hypothesis concerning past geographic patterns of Iberian Abies species. The integration of ecological‐niche characteristics from known occurrences of Abies species in conjunction with palaeoecological studies could constitute a suitable tool to define appropriate areas in which to focus proactive conservation strategies. 相似文献
429.
Talgø V Chastagner G Thomsen IM Cech T Riley K Lange K Klemsdal SS Stensvand A 《Fungal biology》2010,114(7):545-554
Current season needle necrosis (CSNN) has been a serious foliage disorder on true fir Christmas trees and bough material in Europe and North America for more than 25 y. Approximately 2–4 weeks after bud break, needles develop chlorotic spots or bands that later turn necrotic. The symptoms have been observed on noble fir (Abies procera), Nordmann fir (A. nordmanniana) and grand fir (A. grandis) on both continents. CSNN was reported as a physiological disorder with unknown aetiology from USA, Denmark, and Ireland, but was associated with the fungus Kabatina abietis in Germany, Austria and Norway. In 2007, a fungus that morphologically resembled K. abietis was isolated from symptomatic needle samples from Nordmann fir from Austria, Denmark, Germany, Norway, and USA. Sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA of these cultures, plus a K. abietis reference culture from Germany (CBS 248.93), resulted in Hormonema dematioides, the imperfect stage of Sydowia polyspora, and thus the taxonomy is further discussed. Inoculation tests on Nordmann fir seedlings and transplants with isolates of S. polyspora from all five countries resulted in the development of CSNN symptoms. In 2009, S. polyspora was also isolated from symptomatic needles from Nordmann fir collected in Slovakia. 相似文献
430.
濒危植物秦岭冷杉地理分布和生物生态学特性研究 总被引:13,自引:2,他引:13
秦岭冷杉(Abies chensiensis)为中国特有三级保护植物,仅岛屿化分布于陕西、甘肃、四川、河南的秦巴山地和湖北神农架中高山地区,分布海拔1300—2300m。为了对秦岭冷杉种群进行深入研究和有效保护,通过样地调查和相关资料分析,对其地理分布、群落特性、种群特性进行了系统研究。秦岭冷杉群落包含种子植物40科63属102种,可划分成11个地理区系成分,其中温带分布型属占84.21%,热带分布型属占15.79%,温带分布是群落的基本特性。秦岭山区的秦岭冷杉群落可分为5个群丛,基本特点为:生境阴湿;群落郁闭度大,结构复杂;种群个体年龄差异大;天然更新主要发生在保护较好的阴坡林窗地段。秦岭冷杉苗期生长缓慢,在30—70年龄阶段,高生长旺盛;在40—100年龄阶段,胸径生长较快。秦岭冷杉开始结实年龄在30—40年龄阶段,结实间隔期为3—5年。秦岭山区成熟个体平均产球果8个/株,饱满种子56粒/球果。种群更新的关键问题是种子产量低,林下幼苗稀疏,更新缺乏后继资源。种子向幼苗转化率低是生活史中的脆弱环节。在未来经营保护中,应以就地保护为主,通过抚育管理,促进天然更新;丰年应适时采种,就地育苗,扩大人工种群。 相似文献