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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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不同盐度对红树林植物--秋茄的胚轴生长发育的影响 总被引：8，自引：0，他引：8
研究了在不同浓度的人工海水(0．5％，1．5％，2．5％，3．5％)和淡水条件下，红树林植物秋茄（Kandelia candel)胚轴的生长发育情况。结果表明，秋茄胚轴在淡水和0．5％～3．5％盐度范围内发芽率和生根率都很高，在90％以上，没有明显的差异，但高浓度的人工海水(3．5％)对芽的生长有一定的抑制作用；淡水条件下，秋茄胚轴的生根数较少。 相似文献
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水分胁迫对火炬树幼苗生长和生理特性的影响 总被引：5，自引：0，他引：5
以1年生火炬树苗木为试验材料,采用称重控制土壤含水量的方法,设置对照(CK)、轻度水分胁迫(T1)、中度水分胁迫(T2)和重度水分胁迫(T3)4个不同处理组,研究火炬树幼苗的生长和生理特征差异.结果表明:对照组CK火炬树幼苗的株高、基径、生物量积累(叶质量、茎质量和根质量)、主根长度及第一级侧根数量显著高于T2和T3,轻度胁迫(T1)对茎质量和总生物量影响不显著,而显著降低了叶质量和根质量;水分胁迫下,火炬树幼苗Pn和Tr显著降低,抑制了火炬树幼苗生物量积累和火炬树幼苗的根生长,通过提高水分利用效率来提供生长所需要的水分来适应水分胁迫;此外,整个胁迫期间,3个水分胁迫组的脯氨酸含量始终显著高于对照CK,在渗透调节作用中起非常重要的作用;水分胁迫初期导致叶绿素含量增加,提高了水分胁迫的适应能力;由于胁迫初期的抗旱锻炼,胁迫30 d后, 3个水分胁迫组的MDA含量显著低于对照.胁迫后期水分胁迫导致叶绿素含量降低,同时MDA含量与对照相比又有所增加,但增幅不大,说明伤害程度较小. 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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温室内对半红树植物海檬果幼苗进行7个盐度(5、8、11、14、17、20、23 g.kg-1)的胁迫处理,并对各处理下海檬果的生长量、生物量、生理指标和光合速率进行测定,结合生理指标进行适应度分析。结果表明:海檬果的苗高增量、地径增量、叶片数增量,根、径、叶干质量及总生物量随着盐度的上升均呈下降趋势;单株叶干质量和总生物量均在对照处理下值最大,且显著高于其他处理,分别为最小值的23.07倍和4.74倍。低盐处理下海檬果光合作用较强,高盐抑制海檬果光合作用;随着盐度的增大,海檬果幼苗叶绿素总量、叶绿素A含量和根活力呈下降趋势,SOD、丙二醛和游离脯氨酸呈上升趋势。生理指标适应度分析表明,海檬果可耐受盐度为8 g.kg-1的处理,在盐度≥11 g.kg-1处理下呈不适应性生长。 相似文献
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干旱胁迫对蚬木幼苗生长及光合特征的影响 总被引：1，自引：0，他引：1
为探讨蚬木(Excentrodendron hsienmu)幼苗对干旱的适应能力,采用盆栽水分胁迫试验法,比较了田间最大持水量的65%~75%(对照)、50%~60%(轻度胁迫)、35%~45%(中度胁迫)和20%~30%(重度胁迫)4个水分梯度下,蚬木幼苗的生长、生物量分配及光合参数的变化。结果显示,重度胁迫显著抑制了幼苗的株高生长,地径生长受干旱影响不明显;中度和重度胁迫对植株茎、叶及总生物量积累产生显著影响,地上生物量比随土壤干旱增强下降、根生物量比和根冠比增加。干旱胁迫显著降低蚬木幼苗叶片的净光合速率、蒸腾速率和气孔导度。胞间CO2浓度在干旱初期先降后升、气孔限制值逐渐增加;随干旱时间延长和胁迫增强,胞间CO2浓度显著上升,气孔限制值变化趋势与之相反。水分利用效率总体上表现为随胁迫加剧而增强的趋势。胁迫初期,气孔限制因素与非气孔限制因素的共同作用可能导致了蚬木幼苗净光合速率的下降。蚬木幼苗在干旱胁迫下采取降低光合、增加地下生物量分配并减缓生长等适应策略,对干旱具有一定的耐受能力。土壤含水量低于最大田间持水量的65%~75%时,及时补充水分可以保证幼苗正常生长。 相似文献
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研究不同土壤供水条件下黄连木幼苗生长及其耗水规律,可为北方干旱缺水地区黄连木能源林节水育苗工作提供重要参考。采用盆栽试验法,设置了4种不同土壤含水量梯度,分析各供水梯度下苗木生长变化及其耗水特征。结果表明:苗高、地径、生物量等指标在不同水分梯度下差异显著,过高或过低土壤水分含量会降低苗木的茎根比;苗木耗水日进程在生长季各月多呈单峰曲线,4种土壤含水量条件下最大耗水月均在8月份,苗木的月耗水量、总耗水量、平均日耗水量均随着土壤含水量的下降而下降,并且差异显著。综合考虑苗木生长及耗水特性认为:在土壤含水量为田间持水量的60%±5%时,能够实现能源林苗木壮苗的定向培育目标,同时又能实现水分的高效利用。 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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Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions. 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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Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
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《Wood material science & engineering》2013,8(2):76-84
Abstract Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists. 相似文献