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1.
对福建省永安市不同年龄毛竹营养器官N、P、K、Ca、Mg元素分布进行了研究。结果表明,毛竹不同部位的营养元素含量不同,N、P、Ca、Mg元素平均含量顺序为叶>枝>秆>根;K元素含量的排列顺序为叶>根>枝>秆。叶、枝、秆中主要营养元素的排列顺序为N>K>Mg>Ca>P;根中主要营养元素的排列顺序为K>N>Mg>Ca> P。不同营养器官养分元素含量随年龄增长的变化趋势不同,N、P、Ca、Mg在竹秆与竹根中呈先上升后下降的趋势,竹枝中呈降-升-降的趋势,竹叶中呈"W"型变化,K元素除2年生竹秆中含量较高外,在竹秆、竹根、竹枝中呈下降的趋势。毛竹各器官中有14对元素的相关性达到显著或极显著水平,其中与N元素相关的有8对,与K元素相关的有8对,P元素相关的9对。土壤中有机质、N、P、K的含量对竹秆、竹枝、竹叶中N素含量有重要影响,毛竹营养器官中P、K元素浓度与土壤的主要化学指标之间的相关性未达到显著水平。在土壤养分充足的条件下,竹叶器官中的养分浓度主要由其本身的生理特性决定,与土壤养分浓度相关性不显著。竹叶N、P含量与磷酸酶活性显著相关,与过氧化氢酶极显著相关,土壤酶对土壤中所进行的生物及生物化学过程起着重要的作用,土壤中N、P、K等元素在转化为毛竹可吸收过程中有多种酶的参与。竹秆N与土壤毛管孔隙度和总孔隙度极显著相关,与其他的土壤物理指标相关性不明显。 相似文献
2.
研究了百山祖冷杉(Abies beshanzuensis)分布区适生立地表层土壤养分及其与百山祖冷杉枝叶营养元素含量的相关性.结果表明,土壤pH5.11～6.42,土壤有机质含量、全氮含量、速效磷含量、速效钾含量分别为119.075 0g/kg、2.196 2g/kg、15.016 3mg/kg、136.215 2mg/kg;百山祖冷杉对土壤N、P、K富集能力均较高,而对微量元素富集能力较弱,且枝部和针叶均未检出Na元素;较高的土壤N含量,可相应显著提高百山祖冷杉叶N、K含量水平,较高的土壤P含量,则显著抑制百山祖冷杉叶对K和枝对N的积累水平,较高的土壤Cu含量显著降低了Cu元素在叶器官中的积累,而显著增加了枝条中Cu和Zn的积累水平,较高的土壤Fe含量则显著促进了针叶中Fe元素和枝中Fe、Mn元素的积累水平. 相似文献
3.
油茶林果实成熟期养分分配特征 总被引：1，自引：0，他引：1
以常宁市10年生油茶作为试材,对油茶养分分配规律、油茶林土壤养分与树体各器官营养元素含量的相关性进行研究,旨在为油茶营养诊断以及配方施肥提供科学依据。结果表明:油茶各器官中,大量元素含量由高到低排序依次为N、Ca、K、Mg、P,微量元素含量由高到低排序依次为Mn、Fe、Pb、Zn、Cu、Cd;土壤大量元素含量由高到低排序依次为Ca、N、K、P、Mg,微量元素含量由高到低排序依次为Fe、Pb、Zn、Cu、Mn、Cd。土壤养分含量与油茶各器官养分指标具有不同程度的相关性,与油茶干的养分含量相关性最为紧密;土壤N、Zn、Mn、Pb、K含量与油茶植株养分元素含量的关系最为紧密;土壤Mn与油茶各器官Mn元素含量均呈现正相关;土壤N与油茶干中N含量呈现极显著相关;土壤Cd元素含量和油茶各器官中Cd元素含量多存在负相关性。 相似文献
4.
马尾松一代种子园母树营养特点研究 总被引：1，自引：0，他引：1
对马尾松一代种子园母树的针叶和球果的营养元素含量进行测定、分析、比较,结果表明:马尾松种子园母树对氮、钾、钙、磷养分的需求量较大,针叶中各元素含量由高到低依次为NKCaPMgBMo,球果的养分含量为KNCaPMgBMo;种子园母树的针叶、球果中各营养元素含量波动较大;初步得到种子园母树针叶各营养元素含量适宜范围为:N(10.994~13.414 g/kg),P(1.026~1.430 g/kg),K(6.025~15.842 g/kg),Ca(1.784~5.483 g/kg),Mg(0.845~1.233 g/kg),B(28.417~38.854 mg/kg),Mo(1.743~3.012 mg/kg),可作为推测种子园母树营养元素是否分布正常以及种子园施肥和开展配方施肥试验的参考依据之一。 相似文献
5.
在田间试验条件下,采用裂区设计,以三倍体毛白杨无性系S1、S6、S8、S11为试验材料,以二倍体毛白杨S10为对照,采用7种种植密度A1(2 m×2 m)、A2(2 m×3 m)、A3(2 m×3.5 m)、A4(3 m×4 m)、A5(2 m×4 m)、A6(2 m×5 m)、A7(3 m×3 m),研究了不同品种和种植密度对三倍体毛白杨叶片营养元素含量的影响。结果表明:不同的无性系对三倍体毛白杨叶片中N、P、K、Ca、Mg的含量均有极显著的影响。叶片中N含量最高的是S6(27.41 g/kg),P含量最高的是S1(1.88 g/kg),K含量最高的是S8(3.59 g/kg),Ca、Mg含量最高的分别是S10(10.48 g/kg)、S11(4.61 g/kg)。不同种植密度对叶片中N元素的含量有显著的影响,其中叶片含N量最多的是A6,达26.97 g/kg。而不同种植密度的无性系叶片中P、K、Ca、Mg的含量无显著差异。相关性分析表明,各元素之间存在一定的相关性,Mg与Ca之间呈显著正相关,与K之间呈显著负相关。 相似文献
6.
《西部林业科学》2018,(6)
以元阳梯田核心景区坝达、小水井两个区域的森林系统为研究对象,测定土壤各养分含量,分析不同植被类型下土壤各养分的分布特征及空间变异性,对坝达、小水井两个区域的森林土壤p H值、有机碳、氮素、磷素及钾素的含量进行了研究。结果表明,(1)研究区内的森林土壤p H值为4. 61-5. 21,为酸性土壤;(2)土壤有机碳和全氮的含量较高,分别为32. 34-66. 44g/kg和1. 69-4. 63g/kg,处于含量丰富水平;土壤磷元素含量较低,全磷含量为0. 43-1. 64g/kg,速效磷含量介于1. 55-6. 13mg/kg,处于含量缺乏水平;土壤钾元素含量最低,全钾含量为5. 06-21. 06g/kg,速效钾含量介于23. 81-91. 57mg/kg,处于含量贫乏水平;(3)研究表明,坝达和小水井两区的土壤养分变异系数在15%-60%之间,7个养分指标的变异系数都属于中等强度变异性。 相似文献
7.
8.
《林业调查规划》2018,(6)
对闽北马尾松二代种子园母树针叶和球果的营养元素含量进行测定,分析营养元素在母树针叶、球果中的分布特性,根据马尾松二代种子园母树的高、中、低不同产量及其针叶和球果养分含量的差异,初步探讨母树营养元素的适宜浓度范围。结果表明,马尾松种子园母树需求量较大的营养元素主要是钾、氮、钙、磷,针叶的养分含量分布特点为K N P Ca Mg B Mo,球果养分含量分布特点为K N Ca P Mg B Mo;马尾松二代种子园母树针叶的营养元素适宜浓度范围为N(7. 898～11. 831 g/kg),P(2. 798～4. 473 g/kg),K(12. 673～15. 010 g/kg),Ca(0. 945～2. 982 g/kg),Mg(0. 739～1. 573 g/kg),B(11. 226～45. 799 mg/kg),Mo(0. 161～0. 923 mg/kg)。 相似文献
9.
伏牛山南北坡针阔混交林土壤养分对比分析 总被引：1，自引：0，他引：1
研究秦岭东段伏牛山南坡和北坡针阔混交林土壤的养分状况,有助于对该区森林土壤的保护及改良提供理论基础。在伏牛山南坡的宝天曼和北坡的白云山设置样地,分层采集土样,对比分析土壤有机质、全氮、速效磷、速效钾、pH值的分布特征及变异情况。结果表明:(1)伏牛山北坡土壤肥力水平高于南坡,除pH值小于南坡外,北坡的有机质、全氮、速效磷和速效钾平均含量分别比南坡高1.91 g/kg、0.41 g/kg、16.97 mg/kg、7.62 mg/kg;南坡和北坡土壤养分垂直分布均呈现出表聚性特征。(2)土壤pH值随土层的变化不明显,但略有上升。(3)各层土壤养分均表现为中等变异,变异系数在13%~69%之间。0~20 cm土层养分的变异系数相对较小。(4)伏牛山南坡和北坡的土壤养分含量与土层深度之间有着较显著的回归关系,R2在0.472~0.692之间。土壤pH值与土层深度之间的回归关系不显著。(5)相关分析表明,有机质与全氮呈极显著正相关,且与速效磷、速效钾之间存在不同程度的正相关关系,土壤养分与土壤pH值之间多呈负相关关系。 相似文献
10.
森林生态系统营养元素的积累和循环是维护森林生态系统健康稳定的关键因素之一,对森林生态系统的存在和发育具有重要的意义。文章对寒温带兴安落叶松林生态系统的养分输入、贮藏和输出特征进行了初步的研究。结果表明:林冠对Ca、Mg、Fe总体呈现吸附趋势,其中对Ca元素的吸收最为显著;P、K元素则是经林冠后含量增加;微量元素Mn的输入主要来自降雨,林冠对其的利用很少;各元素在植物和土壤中贮存的比例存在较大的差异,其中Ca、Mg、Mn主要贮存于植物体中,其贮存量约占86.06%、84.25%和94.18%;植物体中P、K的贮存量约占总贮量的44.62%和58.82%;Fe主要贮存于土壤当中,植物体中Fe的贮存量仅占总贮存量的9.16%;在兴安落叶松林生态系统中径流输出是养分元素主要的输出途径,其中P、K、Mn元素的年输入量大于输出量,生态系统中养分含量呈累积增加趋势,而Ca、Mg、Fe元素的输出量大于输入量,表现为养分流失,其中Ca的损失量最大。 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
14.
《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
15.
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
16.
《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
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