稀土对梨树生长及产量影响试验

在黔中地区 ,用不同浓度的稀土液对沙梨进行叶面喷施 ,分别对生长量、粒重、单株产量 ,每 1/15公顷产量进行试验研究。试验结果表明 :施用稀土对梨树的生长及产量有较高影响 ,不同浓度 ,效果不一     

稀土在林业上的应用

稀土在林业上的应用１．稀土对植物的影响：稀土对植物的生理影响大致是：可以提高植物叶绿素的含量，强化光合作用；促进根系发育，增加矿物元素的吸收；增强作物对低温、干旱、病毒的抗御能力；有利植物的生长发育，增加产量。例如：用稀土喷施板枣，座果率和株产量比对...     

冀北山地施用稀土提高林果产量试验示范成果初报

１９９１年以来，承担“冀北山地应用稀土提高林果产量试验与推广”课题，试验结果表明，于苹果、山楂等主产果树，落叶松、油松、杨树等主要造林苗木，喷施稀土能显著提高果树产量、果品质量和苗木生长量。并筛选出最佳浓度和施用时间。     

稀土微肥对油茶植株生理指标及产果量的影响

以油茶为试验材料，研究了稀土微肥对植物体叶绿素含量、可溶性蛋白质含量、核糖核酸酶的活性、光合速率、植株生长和产量的影响。结果表明，施用适量稀土微肥可以促进油茶春梢生长和叶面积增加，提高2年生叶片叶绿素、可溶性蛋白质含量，抑制核糖核酸酶的活性，增强光合速率，延缓3年生叶片的衰老，从而提高油茶的坐果率和单株产量。     

赤霉素（GA3）、吲哚丁酸（IBA）和稀土对锥栗产量促进作用的研究

运用双因素随机区组设计方案，研究了稀土、赤霉素（GA3）和吲哚丁酸（IBA）三种植物生长调节剂对三信锥栗品种无性系产量增加的影响。结果表明：稀土微肥不员浓度喷施对产量有显著的影响，以400ppm(A1)为最佳；两种生长调节剂中，则以GA3的效果更好（B1）；AB因素两种组合的混合喷施对产量的促进有交互作用，各种组合中以A1B1，即稀土浓度为400ppm，GA3浓度为50ppm的交互效应对产量的提高最显著。     

稀土在枣树上的应用试验

１９８７～１９８９年在枣强县孟在村对马莲小枣在花期、果实膨大期喷施６００ｐｐｍ、８００ｐｐｍ、１０００ｐｐｍ浓度的稀土试验。试验结果表明，能提高马莲小枣座果率，产量及品质以喷施８００ｐｐｍ浓度的稀土表现最佳。     

稀士氨合成催化剂

稀士氨合成催化剂华南理工大学与广东阳山氮肥厂共同承担的国家火炬计划项目“稀土氨合成催化剂”在广州通过国家科委的验收和技术鉴定。这是一项充分利用我国丰富的稀土资源，为合成氨工业生产提供一种高效催化剂，提高合成氨产量，并达到国际领先水平，实现产业化的成果...     

稀土不同混配肥对板栗产量的影响

试验表明,对板栗树施用稀土生物有机肥与施用复合肥相比,产量差异达到极显著水平,增产幅度达29.38%～48.97%。稀土生物有机肥集有机肥、无机肥、稀土及微量元素混为一体,有良好协同肥效作用,加上叶面补充喷施稀土,使肥效更持久,可源源不断地向板栗树体供肥,有效地提高板栗产量。     

马尾松苗期施用稀土试验初报

马尾松苗期施用稀土，不仅可以提高苗木质量，苗高增加21．5％，地径粗增加10．8％，提高Ⅰ、Ⅱ级苗5％的产量，而且具有成本低，使用方法简单，安全容易推广等优点。     

葡萄施用稀土方法

葡萄施用稀土可提高葡萄产量(27-35％)、果实含糖量，每亩可增加收入83元。方法：(1)喷施浓度为0．05～0．40%，即1kg农用稀土“常乐”加水1000kg或2000kg。喷洒时以雾滴布满叶片不下滴为宜；     

板栗喷施稀土丰产试验及效益分析

采用随机区组田间试验进行叶面喷施。通过对１００ｐｐｍ、３００ｐｐｍ、４００ｐｐｍ、５００ｐｐｍ、７００ｐｐｍ和一个清水对照进行处理和分析,最后得出３００ｐｐｍ可以提高百粒重、座果率、单株产量。     

宁夏沙边子的土壤动物多样性

土壤动物是指其生活中有一段时间定期在土壤中度过并对土壤有一定影响的动物(尹文英,2001),是土壤生态系统中不可分割的组成部分,它们在分解残体、改变土壤理化性质、土壤形成与发育、土壤物质迁移与能量转化等方面有重要的作用(朱永恒等,2005).土壤动物在陆地生态系统中具有种类繁多、数量巨大、适应性强、分布区广等特点.     

轻稀土尾矿库区植被修复的镧、铈富集植物筛选

【目的】测定我国北方某轻稀土尾矿库区的土壤轻稀土元素含量及植物中镧、铈元素含量和分布,分析植物对轻稀土元素镧、铈的转移系数和吸收系数,筛选镧、铈富集植物,以期发现轻稀土富集植物,为尾矿库景观生态恢复提供理论依据。【方法】以稀土尾矿库区尾矿坑的边缘绿地为研究样地,依据风向将采样点设置在东南、西北、东北和西南4个方向,从矿坑边缘由近及远依次设置在50,100和300m边坡处,共计12个采样点。利用五点采集-四分法收集0~20cm表层土壤样品,在采样点采集修复工程栽植的6种植物(梭梭、小叶锦鸡儿、花棒、胡枝子、白刺和毛白杨)地上器官和根部样品。采用ICP法测定土壤中轻稀土元素镧La、铈Ce、镨Pr、钕Nd、钐Sm、钷Pm和铕Eu含量及植物中镧和铈含量。采用N.L.Nemerow综合指数法分析轻稀土尾矿库周边土壤单因子污染指数平均值,采用生物转移系数评价植物转移效率,采用生物吸收系数评价植物吸收土壤中镧和铈的能力。【结果】轻稀土尾矿库土壤中La,Ce,Pr,Nd,Sm,Pm和Eu的平均含量分别为2762.46,5440.42,1308.42,1604.11,133.96,28.12和40.53mg·kg-1,镧、铈含量之和占测试样品轻稀土总量的72%;各方位表层土壤中轻稀土含量表现为东南>东北>西南>西北,且高于内蒙古土壤含量几何平均值(背景值)25.10~230.56倍,且各方向土壤的单因子污染指数均大于3,确定研究区土壤属重度污染;东南单因子污染指数平均值为69.06~544.10,污染值最高,西北单因子污染指数平均值为5.99~19.75,污染值最低,东北和西南单因子污染指数平均值相似;梭梭、胡枝子和白刺体内La和Ce含量均表现为地上器官>根,小叶锦鸡儿、花棒和毛白杨体内La和Ce含量均表现为根>地上器官;梭梭、胡枝子和白刺的镧、铈转移系数为1.03~1.76,胡枝子的镧、铈吸收系数为1.00~1.72,只有胡枝子的镧、铈转移系数和吸收系数均大于1。【结论】胡枝子是轻稀土元素镧、铈的富集植物,可用于轻稀土污染土壤修复,其他5种植物可作为轻稀土元素的耐受性植物应用。     

Seedling emergence of Betula maximowicziana following human disturbance and the role of buried viable seeds

We observed seed rain and seedling emergence of a pioneer tree species, Betula maximowicziana Regel., for 5 years at various sites differing in canopy and soil surface conditions, and clarified that a buried seed bank contributed to the recruitment of B. maximowicziana seedlings. More seedlings emerged at sites where the soil surface had been disturbed than at sites where the soil surface had not been disturbed. Within each soil surface condition, the densities of the emerged seedlings were generally proportional to the densities of the seeds dispersed the previous year. However, the seedling densities were disproportionately higher than the dispersed seed densities at the sites where the soil surface had been disturbed in the previous year. Soil samples taken during different seasons indicated that B. maximowicziana maintained a persistent seed bank in the soil below 1 cm deep, while it formed a more transient seed bank in the top 1 cm of the soil. The seed rain in the previous year was the primary contributor to the establishment of B. maximowicziana seedlings in a year after a mast seed year. On the other hand, the soil seed bank had a compensational role in a year after a poor seed year. Canopy cover did not affect seedling emergence. Therefore, the previously reported lack of a persistent seedling bank of B. maximowicziana under a canopy will be partially attributed to a relatively rare soil surface disturbance in a stable stand.     

盆土基质试验

根据南方土壤偏酸而北方土壤偏碱的特点,对南方珍稀阴笥观叶花木组培苗的盆土基质进行了改良试验。结果表明：以盆土Ⅰ号,Ⅱ号为基质能够有效降低北方土壤的ｐＨ值,以普通自来水＋０．２％ＦｅＳＯ４＋０．１％（ＮＨ４）２ＳＯ４为浇灌水定期浇灌,可有效地防止盆土再碱化,使基质保持一定的酸碱度,从而使该花木在北方亦能生长好。     

红楠的价值、育苗和造林技术

红楠是我国重要的优良珍稀树种,具有较高的观赏、用材价值和保持水土的生态功能。文章介绍了红楠的容器育苗、造林以及病虫害防治技术等。     

七子花的研究进展及其保护对策

从资源状况、土壤的理化性状、种群、群落、遗传多样性以及保护对策6个方面概述了国家二级重点保护植物——七子花的研究进展。七子花间断分布，分布范围小、数量少，并呈衰退的趋势，有灭绝的危险，其主要原因是遗传多样性较低、环境适合度差及人为破坏作用。最后提出七子花的几点保护对策。     

林木抗旱生理研究进展

从林木的表型特征、生理生化特性、抗旱分子生物学与抗旱基因表达3方面对国内外林木抗旱性研究进行综述。当前国内外学者对植物叶茎根的表形特征、渗透调节、光合生理、叶绿素荧光变化、活性氧代谢、植物激素的研究较多, 而对受干旱胁迫下林木的分子生物学与基因表达研究相对较少。最后提出了林木抗旱生理研究的主要评价方法、研究指标、研究方法与内容。随着技术的发展及相关研究的深入, 抗旱分子生物学与抗旱基因等方面的研究将成为林木抗旱生理方面的热点。     

On the sustainable productivity of planted forests

Planted forests have more than a millennium of history and represent the world's best hope for meeting global wood requirements in the twenty-first century. Advances in genetic improvement, nursery practices, stand establishment, and tending, harvesting, and manufacturing have boosted plantation yields to a higher level than at any point in history. Despite this, forest managers face a mounting challenge to demonstrate that plantation productivity is sustainable. Tackling this challenge requires a sound understanding of the principles of forest productivity, how they apply to a developing plantation, and how they are influenced by management. In this paper criticisms of plantation forestry are discussed from the basis of world experience, and examples of productivity decline are described. Obvious declines are rare, and can be attributed to poor soil management. However, ambiguities exist and controversy will continue until sustainable productivity can be demonstrated conclusively. Proposed programs aim to provide the technical base needed for sound soil management and sustainable plantation productivity.     

Responses of soil carbon, nitrogen and cations to the frequency and seasonality of prescribed burning in a Cape Cod oak-pine forest

Fire is an important component of the historic disturbance regime of oak and pine forests that occupy sandy soils of the coastal outwash plain of the northeastern US. Today prescribed fire is used for fuel reduction and for restoration and maintenance of habitat for rare plant and animal, animal species. We evaluated the effects of the frequency and seasonality of prescribed burning on the soils of a Cape Cod, Massachusetts's coastal oak-pine forest. We compared soil bulk density, pH and acidity, total extractable cations and total soil carbon (C) and nitrogen (N) in unburned plots and in plots burned over a 12-year period, along a gradient of frequency (every 1–4 years), in either spring (March/April) or summer (July/August). Summer burning decreased soil organic horizon thickness more than spring burning, but only summer burning every 1–2 years reduced organic horizons compared with controls. Burning increased soil bulk density of the organic horizon only in the annual summer burns and did not affect bulk density of mineral soil. Burn frequency had no effect on pH in organic soil, but burning every year in summer increased pH of organic soil from 4.01 to 4.95 and of mineral soil from 4.20 to 4.79. Burning had no significant effect on organic or mineral soil percent C, percent N, C:N, soil exchangeable Ca²⁺, Mg²⁺, K⁺ or total soil C or N. Overall effects of burning on soil chemistry were minor. Our results suggest that annual summer burns may be required to reduce soil organic matter thickness to produce conditions that would regularly allow seed germination for oak and for grassland species that are conservation targets. Managers may have to look to other measures, such as combinations of fire with mechanical treatments (e.g., soil scarification) to further promote grasses and forbs in forests where establishment of these plants is a high priority.