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1.
采用Li-6400便携式光合测定仪对5种华南地区常用园林绿化藤本植物进行了光响应曲线的测定,并用非直角双曲线模型对其进行拟合,对比分析了5种藤本植物的光补偿点（LCP）、光饱和点（LSP）、最大净光合速率（Pn）、最大表观量子效率（ɑ）。结果表明：5种藤本植物对光照的响应存在着显著差异。使君子的LCP和LSP都比较低,能够充分利用弱光并具有较强的耐荫性;常春麻油藤的LCP和LSP高,对有效光能辐射的利用范围较宽。5种藤本植物的光合速率随光合有效辐射强度的增加出现先升高后平缓的趋势;气孔导度随光强的上升均呈现先上升后降低的趋势;叶片胞间CO2浓度随着光强增大均呈现先快速降低后趋于稳定的趋势;蒸腾速率呈现出线性平缓增长的趋势;而水分利用效率则呈现出先上升后下降类似抛物线的变化。 相似文献
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以东兴桂(Cinnamomum cassia)、西江桂(Cinnamomum cassia)、清化桂(Cinnamomum cassia var.macrophyll)3个不同品种肉桂为试验材料,使用Li6400便携式光合作用仪测定分析了光合生理指标光合速率(Pn)、胞间CO_2(C_i)、气孔导度(G_s)、蒸腾速率(T_r)及水分利用率(R_(WUE))对光辐射梯度的响应变化;并且比较了光饱和点(LSP)、光补偿点(LCP)、最大净光合速率(P_(max))、表观量子效率(α)和暗呼吸速率(R_d)等光合特征参数。结果表明,3个品种的P_(max)均小于10.0μmol/(m~2·s),LSP小于或接近600.0μmol/(m~2·s).西江桂的LCP、LSP最小,表明西江桂耐弱光,但不耐强光。清化桂的P_(max)仅次于西江桂,LCP居中,LSP则最大,表明清化桂适应光环境的范围最广,且较耐强光。东兴桂的P_(max)最小,LCP最大,LSP居中,表明东兴桂耐弱光的能力最差,耐强光能力居中。通过比较不同肉桂品种的光合能力差异,发现西江桂比较耐弱光,更适合复层林经营或选择阴坡或半阴坡造林。 相似文献
3.
藤本植物是城市绿化中不可缺少的一大类别,尤其是用于垂直绿化、屋顶绿化。适合山东省滕州市的藤本植物有紫藤、凌霄、爬墙虎、葡萄、小叶扶芳藤、络石、藤本月季、蔷薇等乡土植物,还有近年引进的常春藤、五叶地锦、猕猴桃等。现分别介绍其生活习性。凌霄。落叶木质藤本,多皱缩卷曲,黄褐色至棕褐色,完整花朵长4～5厘米。萼筒钟状,长2～2.5厘米,裂片5,裂至中部,萼筒基部至萼齿尖有5条纵棱。气清香,味微苦、酸。花期长,开花数量多,花朵大,鲜艳夺目。适应性较强,性喜阳、温暖湿润的环境,稍耐阴。喜欢排水良好土壤,较耐水湿并有一定的 相似文献
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《山东林业科技》2016,(6)
以3a生小叶扶芳藤和三叶地锦幼苗为材料,用LI-6400型光合仪测定全光照、40%遮光和70%遮光处理下其叶片净光合速率(Pn)、蒸腾速率(Tr)和水分利用效率等光合参数日动态特征,分析比较不同遮光处理对小叶扶芳藤和三叶地锦光合特性的影响。结果表明:不同遮光处理下,三叶地锦叶片Pn日变化均表现为单峰曲线,小叶扶芳藤叶片Pn日变化在全光照和40%遮光处理下呈单峰曲线,70%遮光处理下呈双峰曲线。小叶扶芳藤和三叶地锦Pn日均值、日最大值均在全光照处理下达到最大,小叶扶芳藤在40%、70%遮光处理下Pn峰值分别比全光照下降57.80%、80.24%,三叶地锦叶片Pn峰值下降55.1%、76.86%。随着遮光处理的加重,小叶扶芳藤和三叶地锦叶片Tr均呈下降趋势,40%、70%遮光处理下小叶扶芳藤叶片最大Tr分别比全光照显著下降46.68%、55.60%,三叶地锦叶片最大Tr比全光照处理下降41.48%、74.00%;不同遮光处理下小叶扶芳藤和三叶地锦叶片水分利用效率日均值均表现为全光照70%遮光40%遮光。小叶扶芳藤和三叶地锦较喜光,但对弱光也有一定的利用能力,能有效运用于城市园林绿化。 相似文献
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比较研究了幼龄和成龄锯叶竹节树净光合速率对光强的响应特性及主要生理和环境因子的日变化进程。结果表明,成龄树的光饱和点(LSP)、光补偿点(LCP)、光饱和光合速率(Pmax)和表观量子效率(AQY)分别为836、6.18、9.52和0.047μmol.m-2.s-1;幼树的LSP、LCP、Pmax和AQY分别为359、2.79、5.05和0.036μmol.m-2.s-1。成龄树的Pmax和LSP较高,LCP较低,对强光和弱光的适应性均较强;幼树的Pmax、LSP、LCP和AQY均较低,对弱光的适应性强,但较低的光合能力和量子效率延长了锯叶竹节树的幼龄期。幼树和成龄树的环境最大光强均低于其LSP,其净光合速率日进程也均为单峰曲线,没有明显的"午休"现象;气孔导度和蒸腾速率的日变化趋势也均基本与Pn一致。在迁地保护时,应选择较为荫蔽的环境定植。 相似文献
8.
地锦生理生态特性研究进展 总被引：2，自引：0，他引：2
上海农学院园林环境科学系经过4年的重复测定和对比试验，取得了墙面绿化材料地锦在暑期中的降温增湿效应的数据。利用人工气候室，通过CO2气体分析仪等仪器的测定，测得了地锦、美国地锦、青龙藤的补偿点，光饱和点以及光合强度与温度相互关系的数据。利用751分光光度计等仪器的测定，测得地锦、美国地锦、青龙藤的叶绿素a、叶绿素b的数据。从而为在本市大力推广垂直绿化对墙面绿化的树种的选择提供了科学依据。地锦生理生态特性研究进展@尚农 相似文献
9.
土壤水分胁迫对胡杨、灰叶胡杨光合作用-光响应特性的影响 总被引：34，自引：1，他引：34
采用盆栽试验研究正常供水(土壤相对含水量70%～80%)、中度水分胁迫(50%～60%)和重度水分胁迫(30%～40%)条件下,胡杨和灰叶胡杨2年生幼苗光合作用-光响应特性.结果表明:胡杨、灰叶胡杨光合作用-光响应曲线符合非直角双曲线函数.在正常供水条件下,胡杨、灰叶胡杨的最大光合速率(Pn max)分别为24.59、16.68 μmol CO2· m-2s-1,表观光合量子效率(AQY)分别为0.059、0.036 μmol CO2·μmol-1photons,光饱和点(LSP)分别为603、517 μmol photons·m-2s-1,光补偿点(LCP)分别为42、41 μmol photons·m-2s-1、暗呼吸速率(Rd)分别为2.99、1.45 μmol CO2·m-2s-1.土壤水分胁迫能显著降低胡杨、灰叶胡杨Pn max、AQY、LSP,而对LCP及Rd无显著影响.无论在正常供水还是在土壤水分胁迫条件下,胡杨均表现出更高的光合活性,其Pn、Pn max、LSP、AQY及Rd值均比灰叶胡杨高,而LCP值,二者之间无显著差异.表明生长在同一生境中的胡杨对光照、土壤水分的生态适应能力高于灰叶胡杨. 相似文献
10.
采用盆栽控水法人工模拟干旱胁迫,设置土壤含水量为土壤田间持水量的15%(W1)、30%(W2)、45%(W3)、60%(W4)和充足供水(ck)5个水平,研究干旱对3年生橙红丹桂(Osmanthus fragransChenghongdangui)叶片光合性能的影响。结果表明:①干旱胁迫下,净光合速率Pn、气孔导度Gs、胞间CO2浓度Ci和蒸腾速率Tr降低,水分利用效率WUE升高;②在土壤含水量比较充足的环境条件下(W4和ck),橙红丹桂对强光(1 000~2 000μmol.m-2.s-1)有较强的耐受能力,同时对弱光(0~400μmol.m-2.s-1)也有较高的转化和利用效率;③干旱胁迫下,表观量子效率AQY、光饱和点LSP、表观羧化效率ACE降低,光补偿点LCP、CO2补偿点CCP升高。 相似文献
11.
《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
12.
《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
13.
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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《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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《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
16.
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
17.
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
18.
《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
19.
《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
20.
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