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杉木连栽地力衰退效应研究 总被引：4，自引：0，他引：4
调查分析显示，杉木连栽导致林地生产力下降、土壤肥力减退、物理性状变差及土壤微生物数量和酶活性降低。盆栽试验表明，杉木连栽0-20cm表层土，盆栽杉苗成活率只有24.4%，生长量比同层头栽土下降41.8%。经连栽与头栽造林试验，结果表明连栽林地杉木保存率比头栽下降13.2%，连栽杉木高生长明显低于头栽杉木。采用回心土造林，连栽杉木保存率提高16.8%，树高生长量提高37.9%-60.2%。研究认为，不利于杉木连栽生长的限制因子集中在0-20cm表土层，是导致杉木连栽成活率和生长量下降的一个重要因素。 相似文献
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杉木采伐后连栽杉木是当前生产中急需解决的技术难题。研究认为杉木连栽后生长量下降，一代不如一代，连栽后生长量仅为头栽的70％，第三代就更差，其原因是杉木连栽后，土壤有机质、全氮、全磷等营养元素含量和土壤活性降低，致使生长量下降，因而提出杉木采伐后营造混交林。藉以恢复地力和提高产量。这些研究成绩很大，主要是从外因进行研究，仍未突破杉木采伐后连栽杉木的技术难题。 相似文献
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杉木连栽林地土壤特征和回心土造林更新技术研究 总被引：2，自引：0，他引：2
杉木连栽与头栽土壤的研究表明，连栽引起土壤物理性状变差，土壤有机质，Ｎ、Ｐ、Ｋ养分含量下降，土壤微生物数量减少、酶活性和呼吸强度下降。经盆栽试验、连栽造林试验表明，不利于杉木连栽生长的限制因子集中在表土层，采用回心土造林技术，杉木生长量和保存率显著提高。 相似文献
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杉木人工林地力衰退原因及对策综述 总被引：3，自引：0，他引：3
杉木为速生用材树种，为我国解决用材短缺问题起到了重要作用。但目前由于片面追求速生丰产，营造大量杉木人工纯林，导致了杉木人工林林分生产力下降，林地地力衰退，尤其是在多代连栽杉木林地上，林地地力衰退问题就更加突出和严重。文章综述了我国杉木多代连栽人工林地力衰退的原因以及防止地力衰退的对策。 相似文献
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在全国杉木中心产区的闽北林区,选择不同栽植代数、不同立地及不同发育阶段杉木人工林,进行多代连栽对不同发育阶段杉木人工林生长力影响的系统研究,结果表明:多代连栽对不同发育阶段杉木人工林生产力有较大影响。随栽植代数增加,不同发育阶段杉木林平均木生物量、林分生物量及林分净生产力均呈逐代下降趋势,表现为1代>2代>3代,其中2代16地位指数不同发育阶段杉木林林分生物量比1代下降1 45%～11 68%;3代杉木比1代下降17 44%～60 53%,比2代下降16 23%～55 31%,多代连栽导致了杉木人工林生产力的明显衰退。 相似文献
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Staffan Jacobson Hagos Lundström Sten Nordlund Ulf Sikström Folke Pettersson 《Scandinavian Journal of Forest Research》2014,29(7):675-685
Increasing use of forest fuels for energy production is generating greater quantities of wood ash. In Sweden, it is recommended that this ash should be returned to the forest to counter soil acidification and avoid potential future nutrient deficiencies, but the effects on tree growth require clarification. Thus, 10 field experiments were established in Sweden in 1990–2006 to study the effects of adding wood ash of various origins, doses and combinations of both ash and nitrogen on stem growth in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) stands on mineral soil. Observations after 5–15 years show that growth responses were strongest when N was added, either alone or with wood ash. Growth responses to additions of wood ash without N were small and variable and statistically insignificant at all study sites. However, there were indications that adding wood ash may increase stem-wood growth at fertile sites and decrease it at less fertile sites. Hence, at fertile sites, it may compensate for the growth reductions that normally follow whole-tree harvests, at least temporarily, presumably due to its effects on soil N turnover. At less fertile sites, adding N is probably essential to counteract these growth reductions. 相似文献
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Toru Taniguchi Ken-ichi Konagaya Manabu Kurita Naoki Takata Katsuaki Ishii Teiji Kondo Fumiaki Funahashi Seiichi Ohta Tomomi Kaku Kei’ichi Baba Rumi Kaida Takahisa Hayashi 《Journal of Wood Science》2012,58(6):550-556
Xyloglucan is thought to be a key hemicellulose cross-linking adjacent cellulose microfibrils in plant cell walls. The growth traits of transgenic poplars (Populus alba) with decreased xyloglucan from overexpression of Aspergillus aculeatus xyloglucanase were characterized during a 4-year field trial. The field-trial site consisted of two blocks, a fertile soil block and a non-fertile soil block, determined by soil analysis. In the fertile block, the growth of aboveground biomass of the transgenic poplars was reduced to 24?C44?% compared to that of wild-type poplars, in contrast to the growth seen in chamber and greenhouse conditions. In the non-fertile block, the aboveground biomass of transgenic poplars was also smaller than that of the wild-type poplars. Because poplars reproduce asexually by root suckers, we also compared the formation of root suckers from transgenic and wild-type poplars. Root suckers formed less frequently from transgenic poplars than from wild-type poplars. The growth rates of root suckers from transgenic poplars were also slower than those from wild-type poplars. The results showed that constitutive degradation of xyloglucan impairs poplar growth and vegetative reproduction ability. 相似文献
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The biomass of small and large fine roots (相似文献
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通过在温室条件下施加不同剂量的重过磷酸钙(0,50和100mg·kg-1P),对典型水铝英石土壤(Orthic Allophanic Soil)的土壤植物有效磷、磷素营养和伴生有金雀花(Cytisus scoparius)或黑麦草(Lolium multiflorum)的辐射松苗木生长变化情况进行了研究。结果表明,施加磷肥增强了辐射松根际和磷素匮乏土体的有效磷。与辐射松苗伴生的金雀花、黑麦草根际土壤有效磷也增加。辐射松新枝和老枝松针、茎和根系中磷含量随施加重过磷酸钙剂量的增加而增加;但是金雀花、黑麦草对辐射松苗磷素营养的影响依赖于土壤磷状态。未施肥处理下,与金雀花伴生的辐射松新枝和老村松针、茎和根系中磷含量要高于与黑麦草伴生的辐射松苗,而施肥处理下,结果相反。这可能与金雀花生长大量消耗土壤中有效磷有关。因为,在两个施肥剂量(50mg·kg-1P和100mg·kg-1P)上,与金雀花伴生的辐射松根际土壤中Bray-2磷含量始终低于与黑麦草伴生的辐射松根际土壤。此外,在施肥浓度100mg·kg-1下,与金雀花伴生的辐射松苗干特质量低于黑麦草伴生的辐射松。说明在中、高施肥水平,辐射松苗与黑麦草伴生生长好于与金雀花伴... 相似文献
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A. Kalinganire 《Forest Ecology and Management》1996,80(1-3):279-285
The growth of Grevillea robusta A. Cunn. ex R.Br. in plantations and on farms was assessed on 67 sites selected at random in the major ecological zones of Rwanda. The following parameters were assessed: diameter at breast height, tree height, altitude above sea level, annual rainfall and temperature, soil pH, soil type, soil fertility, soil depth, spacing and forest type (plantation or farm).
Analyses of variance demonstrated that fertile soil, intercropping and cultivation between trees considerably improved growth performance. However, growth was negatively correlated with altitude, with stands above 2300 m above sea level showing poor growth. In Rwanda with proper management, the species can be grown in plantations and on farms for firewood, poles and sawlogs. 相似文献
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从2006年4月开始进行四倍体刺槐引种栽培试验,3年多的观测试验结果表明,各类型四倍体刺槐适应性强,对土壤要求不严,耐干旱瘠薄,但以在疏松、肥沃、湿润的土壤中生长较快.不同立地条件,饲料型四倍体刺槐组培苗的高、径生长差异极显著;饲料型和速生型四倍体刺槐根繁苗的高、径生长也具有较大差异.同一立地条件,饲料型四倍体刺槐组培苗的高、径生长均显著大于饲料型和速生型四倍体刺槐根繁苗,也略大于二倍体刺槐;饲料型四倍体刺槐组培苗的叶片逐渐发黄和几乎全部脱落时间也较根繁苗晚10 d左右.饲料型四倍体刺槐组培苗是一个具有推广价值的荒山造林和园林绿化优良树种. 相似文献
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旱薄山地优良肉用杏品种的引种研究 总被引：1，自引：0，他引：1
1990年－1999年，在太行山西侧旱薄山地进行了杏树的引种与选育，通过对13个杏品种树体生长量，产量及果实品质的分析，得出阳坡山地宜栽植大黄甜，华县大接杏，大杏梅，银白杏，海东杏；石灰岩山地宜发展大黄甜，大杏梅，华县大接杏;土层较厚，有施肥条件的沟块地宜发生兰州大接杏，山黄杏。 相似文献