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以长春市建植小叶女贞庭院绿篱为研究材料,观测群体花期、单株花期、单花序与单花花期,收集5月份有关气温数据,分析其对花期性状表现是否构成影响及程度。结果表明:2014—2016年小叶女贞开花时间为6月2日至25日之间,3 a群体花期平均为21.3 d,各年度相差在1 d之内,盛花期为12~13 d;单株开花时间最短植株为16 d,最长者为19 d,平均为17.5 d;单花序为8~12 d,单花为4~5 d。小叶女贞为夏初开花树种,此时气温等气象因子稳定,花期基本不受天气微小变化影响,开花时间亦相对稳定。 相似文献
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以长春市引种的庭院树文冠果为材料,对其开花与结实生物学性状进行观测与研究,结果表明:在2011~2014年的气候条件下,自然花期均在5月份,群体花期为18.2 d,盛花期8.3 d,单朵小花花期为8~10 d;3~4月气温是影响花期的主要因素。观测总小花数量为2 527枚,其中;两性花为542枚,雄花为1 985枚,两性花平均所占比例为21.4%。株间果实与种子产量、出种率有显著差异,但种子重量差异不大,变动于976~1 049 g之间。本研究发现,花瓣内侧基部除具紫红色斑点外,有些花朵还具有黄绿色斑点;顶生花序并非完全分化两性花,而侧生花序也可以分化两性花。 相似文献
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为选育油茶春花优良品种,以油茶杂交子代(YZ2×DY2)及亲本[母本(YZ2)、父本(DY2)]为研究对象,调查测定其花期和花器官性状,对花期性状进行分级,并对9个性状(花横径、花纵径、花柱裂数、雌蕊长、雄蕊长、花瓣数、花药数、盛花期相对时间、开花持续时间)进行变异、相关性、主成分、聚类分析。将盛花期相对时间和开花持续时间进行等距分级,筛选出符合良种选育目标的花期类型(95株)和极长持续期类型(43株)。9个性状变异系数为9.75%～35.74%,其中,盛花期相对时间的变异系数最大,花柱裂数的变异系数最小。9个性状的中亲优势率范围为-23.17%～0.84%,除盛花期相对时间外均为负值,所有性状均出现超低亲和超高亲个体。杂交子代群体花药数与其他花器性状之间均呈极显著正相关(P<0.01);盛花期相对时间与花横径、花纵径、雌蕊长、花瓣数、开花持续时间呈极显著相关(P<0.01),与花柱裂数呈显著相关(P<0.05)。根据聚类分析将杂交子代群体分为3个类群:Ⅰ类属于最早花期长花期型:Ⅱ类属于最晚花期短花期型:Ⅲ类属于中花期型。 相似文献
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本文对黄檗开花与结实性状进行了研究,结果表明:长春城市群体不同年份开花时间为5月下旬至6月上旬,花期变动于9～11 d,平均10 d,单株花期6 d;靖宇山地群体不同年份开花时间为6月上旬至下旬,花期变动于12～14 d,平均13 d,开花时间较长春城市群体晚10～15 d.长春城市群体不同年份花前≥10℃有效积温变动于514～597℃,平均576℃;靖宇山地群体变动于601～685℃,平均652℃.花前有效积温的高低是影响开花时间早晚的主要环境因子,在相对有限的地理区域内,低纬度山区的黄檗开花时间要晚于高纬度的平原地区.传粉受精后,子房开始迅速膨大,果实发育至第42 d时,平均横径9 mm、纵径10 mm,最大横径11 mm、纵径12 mm,最小横径7 mm、纵径8 mm,至此体量不再增加直至成熟,早期发育快于晚期.果实未成熟时均为绿色,至8月下旬果皮开始泛黄,并逐渐出现蓝黑色,至9月下旬呈蓝黑色,完成生理与形态成熟;10月上旬开始有果实凋落,至11月末基本全部凋落,相同时间内不同母树间落果量存在差异.各雌株果实成熟时鲜重差异显著,5号雌株最重(每300枚质量为276.81 g),为2号雌株(每300枚质量为110.68 g)的2.5倍.结实有大小年现象,长春市栽培群体每2年或3年丰收一次;同年株间结实状态高度同步,但结实量差异显著. 相似文献
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[目的]在用材林高世代种子园建园材料选择时,最初重点考虑的是其速生性,而对优树的开花物候关注较少。在高世代种子园营建时,无性系的配置常根据其种源在大范围内考虑其开花物候的遗传因素,但即使是小范围内相同种源的无性系,其开花物候也不可能绝对同步。因此,了解种子园无性系的开花物候,可为种子园的集约经营、产量预测、种子遗传品质调控等提供依据。[方法]于2012—2013年,在桂阳县苗圃马尾松二代种子园Ⅰ大区、Ⅴ大区分别随机选取不同类型的无性系10个和25个,对其开花物候进行观测。[结果]表明:不同无性系的雌、雄球花花期起止日期和持续时间均有差异,但无性系间雌、雄球花花期值差异均未达显著水平,35个无性系总体雌、雄球花花期具有一定的同步性;35个无性系雌、雄球花的初花期基本同步,雌、雄球花的盛花期和末花期同步。株间花期差异相对于无性间要大,但雄球花花期较早的植株,其雌球花花期也较早,同一株建园亲本的雌、雄球花花期有一定的同步性。除雌球花的末花期与雄球花的初花期呈微弱负相关外,雌、雄球花的初花期、盛花期、末花期间均呈极显著或显著正相关。各花期的相关性呈现初花期和盛花期的相关盛花期和末花期的相关初花期和末花期的相关,雌球花初花期与雄球花初花期的相关系数最大。坡位对母树的花期有极显著影响,生长在不同坡位的植株,其雌、雄球花花期值差异明显,其大小均为上坡中坡下坡。坡位对花期影响最大的是雌球花的初花期,其次是雄球花的初花期、雌球花的盛花期、雄球花的盛花期,而对雌、雄球花的末花期影响最小。偏北产地无性系的花期相对较早,不同的无性系类型,其雄球花的盛花期和雌球花的初花期的差异显著;雄球花的初花期、末花期以及雌球花的盛花期和末花期差异均不显著。不同的年份,雌、雄球花花期的早晚差异很大,2012年最早初花期较2013年最早初花期早25 d。[结论]桂阳马尾松二代种子园35个无性系总体雌、雄球花花期具有较好的同步性;从开花物候方面考虑,该种子园建园材料选择较合理,对种子园种子产量和遗传品质没有影响。 相似文献
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为划分福建山樱花无系性花期物候,在福建省南平市延平区茫荡镇北山村对42个福建山樱花嫁接无性系进行为期2 a的花期观测。结果表明,无性系间花期物候差异极显著,花芽膨大期、花芽开放期、花蕾出现期、始花期、盛花期和末花期的重复力分别为0.8799、0.8800、0.8386、0.8961、0.8923和0.8679。依据始花期、盛花期、末花期对无性系进行系统聚类分析,42个无性系可分为早花型、中花型、晚花型3类,无性系花期平均时长17 d。以盛花期为目标性状,分别从早花型、中花型和晚花型中各筛选1个无性系,分别为fy49、zx3、fy56,可作为构建长花期福建山樱花观花景观的无性系。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
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本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):472-479
Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken. 相似文献
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Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic
or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts
(stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea
(Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content
as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest
N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized
to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea,
largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for
N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant
components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N
released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures
were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality
components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in
the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols.
Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest
age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its
components are mixed. 相似文献
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A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste
disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization,
(2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two
pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea
(Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect
on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage
sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but
affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral
systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):166-178
This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes. 相似文献