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该试验以淹水时间分别为0.1h/d(CK)、1h/d(D4)、2h/d(D3)、4h/d(D2)、6h/d(D1)5个处理梯度对白骨壤种子萌发和幼苗生长的影响。90d后对白骨壤进行萌发率、株高、叶片数、叶面积指数、根长、生物量及根冠比等指标测定。结果表明:淹水时间为4h/d、6h/d时白骨壤的种子发芽率、幼苗的株高、叶片数、叶面积指数及总生物量均高于0.1h/d、1h/d、2h/d淹水时间处理,而淹水时间为2h/d根冠比较高。 相似文献
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在广东梅州实验地全光照条件下用恒定淹水位淡水培养处理红树植物桐花树幼苗1年,以人工海水(盐度8 g·kg-1)为对照,研究了淡水培养对桐花树幼苗生长发育的影响。结果表明:淡水组幼苗的茎高、基径、胚轴直径等指标显著低于人工海水组,而叶片数则极显著低于人工海水组,在胚轴高、分枝数、叶长、叶宽、叶长/叶宽、根长、根径、根数等指标上差异不显著;淡水组的叶面积比人工海水组大18.11%,差异显著。180天时,淡水组植株的根、茎、叶的生物量及总生物量与人工海水组的相比没有显著差异,但分别比人工海水组低12.50%、18.40%、16.48%、16.32%,两组植株的根、茎、叶生物量的大小均为:茎＞叶＞根;360天时,2组植株的根、茎、叶的生物量及总生物量间差异不显著,但淡水组比人工海水组分别低33.88%、17.48%、28.30%、26.51%,两组植株的根、茎、叶生物量的大小均为:叶＞茎＞根。种植1年后,两组桐花树幼苗的存活率都达90%以上,部分植株有花蕾出现且开花,其中,人工海水组植株先出现花蕾,而淡水组植株相对迟25 天出现花蕾,但淡水组出现花蕾的株数比人工海水组多33.82%。由此可见,淡水对桐花树幼苗大部分形态指标均有显著影响,但桐花树幼苗可以正常生长,且能够开花,表明桐花树对淡水环境具有较强的适应性。 相似文献
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为探究无瓣海桑人工混交林在河口海湾的生态效应问题,采用样方法对福建省厦门市海沧湾16年生无瓣海桑与其它种类红树的人工混交林结构和幼苗天然更新扩散能力进行实地调查。结果表明:①该群落外貌简单、林相整齐、空间层次分层明显。位于乔木一层的是无瓣海桑,位于乔木二层的有无瓣海桑、秋茄、红海榄;位于灌木-小树层的有秋茄、红海榄和白骨壤;位于幼苗层的只有秋茄。②无瓣海桑在乔木层的重要值为35.1%,秋茄在乔木层、灌木-小树层和幼苗层3个不同层次的重要值均为最大。③该群落各多样性指数值均较低,灌木-小树层的各多样性指数值均比乔木层和幼苗层的多样性指数值高。④在4种不同类型样地调查幼苗扩散情况,均未发现无瓣海桑幼苗或历年生的幼树,而乡土红树植物秋茄在4种类型样地中均有幼苗自然生长,白骨壤在光滩中有发现幼苗生长。 相似文献
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依据辽宁冰砬山森林生态系统国家定位观测研究站2014—2016年天然次生林内2m层空气温湿度及林外1.5m层空气温湿度观测数据,分析冰砬山区林内外空气温湿度差异。结果表明:冬季林内气温高于林外,夏季林内低于林外;林内气温日较差低于林外;白天林内气温低于林外气温,夜间林内高于林外;林外月平均空气湿度高于林内;林内空气湿度日较差低于林外;白天林内空气湿度高于林外,夜间林内空气湿度低于林外。森林调节空气温湿度的作用具有规律性。 相似文献
5.
以广西竹山红树林群落为研究对象,调查了红树林群落类型、密度、高度、覆盖度、更新层等,研究表明广西竹山红树林群落从内滩到外滩的演替规律为:桐花树、桐花树+白骨壤群丛→桐花+白骨壤-秋茄+海漆-桐花树+老鼠勒+卤蕨、白骨壤+桐花树→桐花树、桐花+白骨壤。种群分布格局为:桐花树呈集群分布,白骨壤、秋茄、海漆、老鼠簕呈随机分布。该群落人为干扰较多,在较小面积的滩面内集中了相对较多的群落类型,以桐花树群丛和桐花树+白骨壤两种群落为主,呈低矮的单层灌木状。样方中各个滩位均有更新层,且更新层的高度差异显著,表明该地区的红树林群落处于发展的初期。 相似文献
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干旱是主要的环境胁迫因子之一,严重影响植物的分布与生长发育。通过选取辽宁阜新章古台沙地1年生榆树幼苗为材料,采用盆栽控水方法,设置田间持水量80%、60%、40%和20%等4个水分处理梯度,研究干旱胁迫对榆树幼苗株高、基径及叶片、茎和根系生物量分配的影响。结果表明:随着干旱胁迫程度增加,幼苗茎和根系的生物量逐渐降低;但轻度干旱胁迫增加了株高和基径的生长,提高了叶片生物量,以抵御干旱胁迫的影响。中度干旱胁迫下,增加了根系生物量分配的比例,从而更利于获取水分资源适应干旱环境;重度干旱胁迫下幼苗无法存活。在科尔沁沙地,栽植榆树幼苗保证存活生长的最低田间持水量为40%。 相似文献
9.
根据实地测定人工无瓣海桑红树林不同环境下的光照强度,研究了不同光强环境对无瓣海桑幼苗的生长和光合特性的影响.结果表明:随着光照强度的降低,无瓣海桑幼苗的生长和光合特性指标水平均呈下降趋势,且不同光强处理间差异显著.在光照强度为全光照的80％和40％时,幼苗的各项生长指标下降,长势较全光照环境下的幼苗差;在荫蔽初期(2～4个月),弱光环境对幼苗的茎高、叶面积和叶片长宽比的增加有促进作用,随着荫蔽时间的延长,则产生抑制作用,不利于幼苗的生长;当光强达全光照的20％时,幼苗生长极为缓慢.在荫蔽处理180 d时,Sa80、Sa40、Sa20的幼苗死亡率分别为42％、70％、100％;在弱光环境下,无瓣海桑幼苗根、茎、叶的生物量分别下降了90％、80％、91％;随着环境光强水平的下降,无瓣海桑幼苗叶片的叶绿素含量、净光合速率等生理参数均呈下降趋势,各处理间差异显著.试验说明光强不足是造成无瓣海桑幼苗生长和光合水平低下及死亡率较高的主要原因,并对无瓣海桑幼苗的天然更新与自然扩散和人工造林技术进行了讨论. 相似文献
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为探究广西北海大冠沙、党江以及山口地区的红树林群落组成与结构,以其红树林内典型红树林群落作为研究对象,设置8个样地进行典型取样,调查内容主要包括红树林群落物种的种类、株数、盖度以及幼树、幼苗层树种的种类、数量和高度。结果表明:大冠沙地区白骨壤群落林相整齐,群落结构单一,仅生长有白骨壤树种,且林下无幼苗,亦未见有其他植物生长。党江地区桐花树群落长势繁茂,林下桐花树幼苗生长密集;该地区无瓣海桑人工林群落树体高大,树冠较稀疏且连续。山口地区秋茄群落冠幅较大,林下稀疏,秋茄根部发达且粗壮,该群落伴生有桐花树、白骨壤、红海榄;该地区的秋茄、木榄群落内均伴生有其他树种且林下有幼苗以及幼树更新。 相似文献
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From August 2004 to August 2005, three replicate experimental platforms were constructed in a section of the tidal flats in
Yingluo Bay, Guangxi Province to study the growth and physiological responses of Rhizophora stylosa Griff seedlings to tidal waterlogging stress in a diurnal tidal zone. A total of eight tidal flat elevation (TFE) treatments,
i.e., 320, 330, 340, 350, 360, 370, 380 and 390 cm above Yellow Sea Datum (YSD), were created on each platform. The results
showed that lower TFEs (320–330 cm YSD) slightly increased the seedling stem height of 1-year old seedlings, while higher
TFEs (>340 cm YSD) increased the seedling growth significantly. Moderate TFEs (350–370 cm YSD) favored the development of
knots. Number of leaves, leaf conservation rate and leaf area per seedling all decreased dramatically with decreasing TFE.
Lower TFEs caused large damage to Chl a, but Chl b was less affected. The Chl a/b ratio decreased with decreasing TFE. Prolonged
waterlogging induced higher SOD activity in roots, while moderate TFE inhibited the SOD activity in leaves. The POD activity
in roots and leaves increased with decreasing TFE. Waterlogging stress decreased the biomass of individual organs and entire
seedlings. With increasing waterlogging, the biomass partitioning in 1-year old seedlings increased from leaf to stem. The
survival rate decreased sharply from 88.9% to 40.0% as TFE decreased, while more than 80% of the seedlings were able to survive
at the TFE level of 370 cm YSD and above. We propose that the local mean sea level should be adopted as the critical tidal
level for forestation with hypocotyls of R. stylosa along the Guangxi coast. 相似文献
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2019年5-6月,采用浙江龙港种质和福建泉州种质的1年生秋茄树Kandelia obovata容器苗和胚轴在浙江省沿海的宁波钱塘江河口、台州椒江河口和温州瓯江河口滩涂进行种植试验,2020年4月,调查了幼苗生长及土壤化学性质,对比分析秋茄树幼苗生长指标、叶片参数和生物积累量的差异。结果表明,瓯江河口土壤含盐量、有机质、水解氮、有效磷、速效钾与钱塘江河口和椒江河口土壤间存在显著差异(P<0.05),但均满足秋茄树正常生长要求;在三个试验地中,龙港秋茄树种质的保存率均显著高于泉州种质(P<0.05);在钱塘江口,龙港秋茄树种质容器苗和胚轴苗的保存率分别为72.92%和82.78%,而泉州种质仅有33.47%和15.28%,且龙港种质容器苗的分枝数显著高于泉州容器苗(P<0.05),但泉州种质胚轴苗的高生长显著大于龙港种质(P<0.05);在三个试验地中,龙港秋茄树种质容器苗的叶片数和叶面积均显著高于泉州种质(P<0.05),胚轴苗则相反,而泉州秋茄树种质的叶片长和叶片宽在瓯江河口最大,椒江河口最小,龙港种质在三个试验地间均无明显差异;秋茄树幼苗的根、茎、叶干质量和生物积累量均表现出瓯江河口>钱塘江河口>椒江河口,龙港秋茄树容器苗各生物量指标均高于泉州种质,而胚轴苗正好相反。因此,在宁波和台州河口滩涂开展红树林营建适合选择龙港秋茄树种质容器苗,而在温州适合选择龙港秋茄树种质胚轴苗。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(4):322-328
Abstract Actual climate models for central Europe predict prolonged summer droughts. Knowledge on how the interaction between light and water availability affects regeneration will hence be of major importance. In an experiment carried out under controlled conditions, newly emerged beech seedlings were grown in pots with sand during 54 days. Three treatments applying three different light levels (2, 9 and 43% relative light intensity) were combined with two soil water treatments (control and drought). At the end of the experiment, seedlings were separated into leaves, stem and root and the seedlings’ dry mass, leaf area and stem length was determined. Low irradiance (2%) had a strong negative effect on dry weights of seedling components, leaf area and specific leaf mass. Drought clearly affected biomass partitioning for seedlings at high irradiance levels (43%). An interaction between irradiance and drought on biomass partitioning in beech seedlings was observed at medium irradiance level (9%). Within a wide range of light levels in the forests, both light and drought may affect biomass partitioning in young seedlings. 相似文献
14.
以20个云南松半同胞家系的2 a生实生苗为研究对象,对其生物量的累积与分配在家系层次的变异规律进行研究,以期为科学评价云南松苗木质量和提高遗传改良的潜在增益提供依据。结果表明,20个云南松半同胞家系2 a生实生苗的生物量累积与分配指标,在家系间均达到显著或极显著水平的差异。根干重、茎干重、叶干重、地上干重、全株干重、根分配、茎分配、叶分配、地上地下生物量比9个生物量指标的表型分化系数为57.74%~92.86%,家系间方差分量百分比为12.77%~34.03%,变异系数为7.78%~55.40%。叶分配比例的遗传力最高(0.62),其次是地上地下生物量比(0.60)。以地上地下生物量比为依据进行优良性状选择可获遗传增益最高(14.31%)。具较大生物量的苗木,其针叶和茎生物量分配的范围集中在50%和40%附近,对应的根茎比在5.0~10.0之间。 相似文献
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The adaptation responses to different water conditions and the drought tolerance of Sophora davidii seedlings were assessed in a greenhouse experiment. Two-month-old seedlings were subjected to the following water supplies
for 95 days: 100, 80, 60, 40 and 20% of field water capacity. The seedlings at 100% FC had the greatest productivity, height,
basal diameter, branch number, leaf number and leaf area. Water supply <80% FC was the threshold of drought-initiated negative
effects on seedling growth, yield and physiological processes; these parameters were severely reduced at 20% FC, however,
there was no plant death during the experiment. Moreover, water stress decreased leaf relative water content, specific leaf
area, leaf area ratio, and water-use efficiency (WUE), whereas it increased the biomass allocation to roots, which resulted
in a higher root:stem mass ratio under drought. The S. davidii seedlings tolerated drought by maintaining high leaf relative water content and by reducing branching and leaf expansion.
However, low productivity and WUE at 20% FC suggested that seedlings did not produce high biomass under severe drought. Therefore,
prior to introducing S. davidii in forestation efforts, a water supply >40% FC is recommended for seedlings to maintain growth and productivity. These results
provide insights into limitations and opportunities for establishment of S. davidii in arid regions. 相似文献
16.
水分胁迫对白杨杂种无性系生理和生长的影响 总被引：7，自引：0，他引：7
为探索水分胁迫对白杨杂种无性系气体变换和生长的影响,以白杨双杂交杂种新无性系Ｂ４３０苗木为试验材料,在３种水分胁迫条件下,对各无性系生理和生长指标进行了分析。结果表明,在不同水分胁迫下,无性系苗木的Ｐｎ、Ｔｒ,Ｇｓ,Ｌａ,Ｃｉ等日变化模式基本一致,但受胁迫的苗木各生理过程受到明显抑制。各生长指标对水分胁迫的敏感性不同,苗高和单叶叶面积对水分胁迫最敏感,叶片数和生物量的敏感性较差,随着水分胁迫加强, 相似文献
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黄连木苗期年生长节律及其生物量分配规律 总被引：2，自引：0，他引：2
为给黄连木幼苗生产管理提供参考,在定期观测的基础上,研究黄连木苗期年生长动态、生物量积累与分配规律以及植物生长指标与生物量组分的相关性。结果表明:在整个苗期生长过程中,黄连木的苗高、地径、冠幅生长均呈现"S"型曲线,用Logistic生长方程和生长曲线能对其动态生长节律进行很好地拟合。结合实际测量值将黄连木1年生幼苗的生长过程分为4个阶段:出苗期、生长初期、速生期和生长末期。各指标速生期的生长量占其总生长量50%以上;黄连木1年生苗木的地上与地下部分生物量比例为1.78∶1.00;苗木生物量各指标中,地径与苗高、茎干质量、叶干质量显著相关,苗高与茎干质量、叶干质量显著相关,茎干质量与叶干质量极显著相关。 相似文献
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Laurício Endres Celene A. Câmara Vilma M. Ferreira José V. Silva 《Agroforestry Systems》2010,78(3):287-298
The objective of this study was to evaluate the effect of nursery shading on the Yellow-ipe seedling (Tabebuia chrysotricha) growth, photosynthesis, and photosynthetic acclimation after being transferred into direct sunlight. The Yellow-ipe seedlings
were grown under 0, 50, 70 and 95% shade. At the 134th day of sowing, leaf gas exchange and chlorophyll were measured under
current growth shading, after exposure to 15 min and two day full sunlight. With the increase of shading, the Yellow-ipe seedlings
allocated more biomass to the stem and leaves and less to the roots, and there was an increase in the leaf area ratio and
specific leaf area. In relation to 0% of shading there was a increase of 211% in stem, 116% in leaf, and a reduction of 200%
in roots biomass when seedling were grown under 95% of shading. The total biomass accumulation had a high correlation with
collar diameter (r = 0.96). More than 70% of the shading reduced the photosynthesis, and after transferring the seedlings into full sunlight,
more than 50% of the shading induced a reduction in chlorophyll, stomatal conductance, photosynthesis and instantaneous carboxylation
efficiency, suggesting the presence of a photoinhibition process. The Yellow-ipe seedling growth under nursery conditions
should not be done under more than 50% shading, which may result in the lower seedling quality and poorer acclimation to transplantation,
particularly to severe degraded areas with direct sunlight. The species can be used for recovering from totally devastated
forest areas to initial recovery when full canopy are forming. 相似文献
19.
杂种鹅掌楸扦插苗营养元素含量的分布 总被引：1，自引：0，他引：1
本文利用不同浓度的外源激素处理杂种鹅掌楸的扦插繁殖幼苗,并通过烘干法、凯氏法、原子吸收等方法,对扦插繁殖幼苗的根、茎、叶3个器官生物量及其营养元素进行测定。结果表明:不同浓度的外源激素(处理1:IBA50gkg-1+NAA300gkg-1;处理2:IBA50gkg-1+NAA300gkg-1)处理插穗后,根、茎、叶的生物量均有一定程度的提高。在所有的扦插苗中,其根、茎、叶内的含C量差异不大,但茎内的N、P、K、Ca含量较根、叶的少。方差分析结果表明:不同浓度外源激素处理的同一器官后,其C/N及P、K、Ca的含量没有明显的差异;而同一浓度外源激素处理不同器官之间的4种营养元素的含量有显著或极显著的差异。并且扦插生根苗体内营养元素含量较低,在大田栽培时,应及时施肥补充营养,以提高幼苗生长适应能力。图1表4参12。 相似文献