共查询到20条相似文献，搜索用时 64 毫秒
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李宝福 《中南林业科技大学学报(自然科学版)》2004,24(5):42-46
采用裂区区组设计开展肉桂施用氮、磷、钾肥试验研究,通过不同施肥处理对肉桂林生长量、生物量以及叶面积指数影响进行了分析.结果表明:合理施肥能明显促进肉桂人工林的生长、增大肉桂林的叶面积指数,利于生物量的积累,施肥水平不同,其促生效果也不同,N、P、K肥对肉桂林产量的影响具有同等重要的性质;肉桂林的最适施肥量为每株尿素300 g左右、过磷酸钙400 g左右、氯化钾为200 g左右;最大施肥量为尿素330.0 g/株、过磷酸钙388.2 g/株、氯化钾204.5 g/株,养分配比为2.3:1:1.7(wN:wP2O5:wK2O);在类似本试验的立地条件下(Ⅱ类立地级),当施肥量尿素超过450 g/每株、过钙超过450 g/每株或氯化钾超过300 g/每株时,均有可能发生肥害. 相似文献
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对定植2年的桃花心木山地人工幼林进行6个处理的施肥试验,结果表明:施肥对桃花心木山地人工幼林林木的树高、胸径生长有一定的促进作用,但需N、P、K肥一起配合施。此试验最为合理的施肥配方是:G∶100g尿素+200g过磷酸钙+50g硫酸钾,能使树高生长量增加85.1%,胸径生长量增加84.91%;其次为:100g尿素+200g过磷酸钙+100g硫酸钾,能使树高生长量增加69.0%,胸径生长量增加71.07%,最差的施肥处理是:50g尿素+100g过磷酸钙,能使树高生长量增加36.3%,胸径生长量增加10.69%。 相似文献
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通过盆栽试验,采用尿素、过磷酸钙各4个水平共8个处理,研究N、P肥对湿加松幼苗的生长效应.结果表明,尿素和过磷酸钙均对湿加松生长有显著影响;各处理对湿加松地径生长的影响在9-12月差异显著,N-1处理地径最大,P-2处理次之;各处理对冠幅生长的影响在7-11月有显著差异,7月以N-2处理冠幅最大,8-11月则以P-2处理最大;各处理对苗高生长的影响差异不显著.对湿加松苗木生物量和植株N、P含量的分析表明,施用一定量的尿素、过磷酸钙可改善植株的养分状况,过量施用则不利于N、P的正常吸收;湿加松苗木最佳施肥组合是每株施尿素6g＋过磷酸钙30 g＋氯化钾15 g. 相似文献
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对定植3年的思茅松山地人工幼林进行5个处理的施肥试验,结果表明:施肥对思茅松山地人工幼林林木的树高、胸径生长有一定的促进作用,但需N、P、K肥一起配合施,此试验最为合理的施肥配方是:100g尿素+200g过磷酸钙+50g硫酸钾,能使树高生长量增加37.7%,胸径生长量增加29.8%;最差的施肥配方是:50g尿素+100g过磷酸钙,能使树高生长量增加10.8%,胸径生长量增加13.2%。 相似文献
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为明确不同施肥处理对平榛幼苗生长的影响，以平榛幼苗为研究对象，设计9个不同施肥组合，清水为对照，采用方差分析、多重比较等方法，对不同施肥处理的平榛幼苗进行统计和分析。结果表明：不同施肥处理对平榛幼苗生长和苗木质量有显著地影响。不同处理的平榛幼苗苗高、地径、叶片数、根数、根长均高于对照，以N2P2K3处理的苗木生长指标最优，苗木质量最好。在平榛育苗过程中要科学合理进行施肥，在生长季选用10 g/m施尿素+10 g/m磷酸二氢钾+15 g/m硫酸钾的氮磷钾配比肥进行叶面喷施，促进苗木生长，提升苗木质量。 相似文献
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This study presents data on the biomass and net aerial primaryproductivity (NAPP) of two contrasting East Anglian salt marshes.One site was at Tollesbury, Essex where the marshes are of theestuarine type and are subject to marsh degradation and erosionwhile the other site was 130 km to the north at Stiffkey, Norfolkwhere the barrier-type marshes are still actively developing withno signs of erosion. The NAPP was determined by the method ofSmalley with quadrats being harvested monthly with replacement.At the lowest levels at Tollesbury there was Pioneer Marshwhich was dominated by a mixture of Salicornia spp. and Astertripolium. At higher levels at Tollesbury there was LowerMarsh which was dominated by a mixture of Atriplex portulacoides andPuccinellia maritima. Over the four years of the studyPuccinellia became the dominant species following a markeddecrease in the extent and vigour of Atriplex. At Stiffkey theMiddle Marsh was at a much higher level and the vegetation waspredominantly a short dense sward with Atriplex portulacoides,Puccinellia maritima and Limonium vulgare together with smallerquantities of Armeria maritima and Plantago maritima. The meanNAPPs over three years of the Pioneer and Lower Marsh atTollesbury (467 & 519 g m-2 yr-1respectively) were similar butin 1993 the NAPPs recorded at Tollesbury were higher than thoserecorded at Stiffkey (625 & 583 compared with 458 g m-2yr-1).Smalleys method is difficult to apply to communities wherespecies dominance is variable, especially when dominance isshared between species with markedly different growth patterns.The results for NAPP obtained from the salt marshes at Tollesburyand Stiffkey are discussed in relation to results obtained byother workers from comparable areas in England and theNetherlands. Attention is also drawn to the possibly largerbelow-ground component of production that is frequentlyoverlooked. The importance of salt marshes in relation to othercoastal communities lies in the export of a proportion of theorganic matter produced and this mainly depends on theabove-ground production. 相似文献
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Responses of swamp bay,Persea palustris,and avocado,Persea americana,to various concentrations of the laurel wilt pathogen,Raffaelea lauricola 
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下载免费PDF全文 M. A. Hughes S. A. Inch R. C. Ploetz H. L. Er A. H. C. van Bruggen J. A. Smith 《Forest Pathology》2015,45(2):111-119
Laurel wilt, caused by the fungus Raffaelea lauricola and transmitted by the exotic ambrosia beetle Xyleborus glabratus, has killed members of the Lauraceae plant family throughout the southeast United States. A series of experiments were conducted to examine the effects of inoculum concentration on the development of laurel wilt in swamp bay, Persea palustris, and avocado, Persea americana. In each experiment, host plants were inoculated with aqueous suspensions of 102, 103, 104 or 105 conidia of R. lauricola, and plants were rated periodically for external symptom development (wilting and foliar dieback). At the end of experiments, plants were rated for internal symptoms of the disease (discoloration of sapwood) and assayed for R. lauricola on a semi‐selective medium. Symptom severity in swamp bay was significantly lower for the 102 treatment than at higher (103–105) concentrations, whereas 102 and 103 conidia caused less disease than 104 and 105 conidia in avocado. At the lowest inoculum concentration, 67% of the swamp bay plants and 20% of the avocados died by the time the respective experiments were terminated. The pathogen was recovered from a high proportion of the symptomatic sapwood of swamp bay (100%) and avocado (94%), and sapwood discoloration and recovery of R. lauricola from inoculated stems of swamp bay were highly correlated with recovery of the pathogen and symptom development in roots. Clearly, swamp bay and avocado are very sensitive to R. lauricola. The ability of only 100 conidia of this pathogen to kill these hosts suggests that few individuals of X. glabratus or other ambrosia beetles that carry low levels of the pathogen would be sufficient to transmit conidia that infect and lead to disease development. The results are also relevant to the development of disease‐tolerant host selections, as they indicate levels of the pathogen appropriate for use in screening plants for disease resistance. 相似文献
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东莞蕨类植物区系研究 总被引：1，自引：1，他引：0
采用野外调查与查阅标本相结合的方法,对东莞蕨类植物区系及其分布特点进行研究,结果表明:东莞市有蕨类植物37科66属125种,其区系特点为:①分布区类型在科、属、种的水平上皆以热带、亚热带性质为主,占各自总数的64.87%、75.76%与61.60%。②科与属的分布区类型显示出东莞蕨类植物区系从热带向亚热带过渡的性质,与温带蕨类植物区系的联系较弱;在种的水平上,温带成分占总数的28.80%,呈现出热带蕨类植物区系向温带蕨类植物区系过渡的特点。③在种的水平上热带亚洲分布及东亚分布类型构成了东莞蕨类植物区系的主体,各占38.40%和20.80%。④与周边4个地区的比较中,与深圳的相似性为最高,与乐昌的相似性为最低;总体上,东莞蕨类植物区系与周围地区关系较为密切。 相似文献
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We carried out an ethno-medico-biological investigation in the interior of Bhadrak district, Odisha, India to explore the therapeutic use of traditional plants/animals by local inhabitants. The villagers and rural people used plant and animal species as medicine. We recorded therapeutic use of 18 plant species of 13 families and 12 animal species of seven taxonomic categories. Different plant/animal parts like bark, leaf, flower, seed, stem, root, whole plant, oil, blood, milk, urine and flesh were reported as used in raw or cooked form against 17 specific diseases. Prominent diseases treated by plant/animal remedies were asthma, cardiovascular ailments, diabetes, epilepsy, jaundice, malaria, skin disorder and rheumatism. This study provides a better database for future studies. 相似文献
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Staline Kibet 《Forest Ecology and Management》2011,261(6):949-957
The Kenyan coastal forests make up one of the World 25 Biodiversity Hotspots. They consist of over 140 fragments (the majority with areas less than 0.5 km2) of the once extensive Zanzibar-Inhambane lowland moist forest. The over 60 known Mijikenda sacred Kaya forests and groves scattered along the coastal hinterland form the greater part of this ecosystem. The forests are of biological and cultural significance, and this has been recognized nationally and internationally, with some now listed as World Heritage Sites. The forests are protected by councils of Kaya elders who regulate use of their resources. Increasing human population and subsequent rise in demand for forest products and land for settlement has put a strain on these relic forests. Farm encroachment and extraction of forest products in different Kaya forests have affected the vegetation ecology at varying levels. This study investigated the spatial species distribution, association and regeneration potential of commonly utilized plants in one of these traditionally managed ecosystems. A modified nested plot method was used to collect data in the field.Using TWINSPAN multivariate, and indicator species analysis, two plant communities (Asteranthe and Bridelia) and an undifferentiated vegetation type were identified. Species association in Asteranthe consisted largely of forest dependant species, with a significant presence of woody climbers. It was comprised of two sub-communities namely Manilkara and Scorodophloeos. In contrast the second plant community, Bridelia, was dominated by light demanding species. It comprised one sub-community (Catunaregam) and a seral stage (Keetia). The species diversity and richness was higher in the Asteranthe community compared to Bridelia. Some of the forest species commonly utilized by the local people were observed to regenerate both in open and closed forest habitats while others had seedling recruitment confined to closed forest.Despite some coastal forests showing physiognomic similarity, detailed study shows intra-variation linked to topography, exposition, type and intensity of human perturbation both currently and in the distant past. Clearly, vegetation patterns of coastal forests of eastern Africa change at fairly short intervals.Recruitment of forest specialists is likely to decline if closed forests are opened up by farm encroachment, however their less specialized counterparts can pioneer in re-colonization of disturbed sites if conservation is strengthened. There is need to invigorate traditional management systems of forests with cultural significance by recognizing and giving increased legal mandates to the local custodians. 相似文献
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鸭儿芹等五种森林蔬菜人工栽培技术研究 总被引：1，自引：0，他引：1
采用大棚设施栽培和林下仿生栽培方法对鸭儿芹、三脉紫菀、败酱、马兰和牛繁缕五种森林蔬菜进行人工栽培,结果表明在大棚设施条件下采用以5:1:4的锯木屑 猪粪 黄心土配制的人工基质栽培产量达4715kg/亩.年,比大棚设施条件下的土壤栽培和露地栽培产量高30.1%和87.3%;林下仿生栽培条件下的产量分别是露地遮阳网蔽荫和无遮阳网蔽荫对照的2.3倍和5.1倍。同时还对鸭儿芹等五种森林蔬菜人工栽培的经济效益做了分析。 相似文献
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系统论述卫片色调与坡向、坡度、坡位、林分龄组、郁闭度的关系 总被引：2，自引：0，他引：2
当前 ,人类赖以生存的地球资源与环境面临越来越严重的威胁。如何迅速、宏观、准确、周期性监控资源和环境 ,已被各国和国际环境组织所重视 ,而卫星遥感就具有迅速、宏观、准确、周期性等特点 ,已被各国应用。内蒙古大兴安岭林业调查规划设计院于 1996年松岭林业局森林资源二类调查时就采用了这个先进的卫星遥感技术。现将影响卫片色调的坡向、坡度、坡位、林分龄组、郁闭度的五大因素进行系统研究 ,找出其相关规律 ,为今后的森林资源调查建立标志和目视判读解译标志提供理论依据 相似文献