蓝桉幼林施肥效应研究

在云南省保山市石灰岩红壤地区进行了历时4年的蓝桉幼林N、P、K不同配比的10种处理施肥试验。结果表明，施肥能明显促进蓝桉（Eucalyptusglobulus）幼林的生长；其中处理6、9、10增产效果极显著，树高增加16．31％～20．40％，胸径分别增加18．78％～19．21％，材积增加65．04％～70．19％。有机肥对蓝桉生长有促进作用，施过有机肥的处理10生长始终保持优势；磷肥是蓝桉增产的主要因素，每株施430g钙镁磷肥做底肥能使树高、胸径分别增加14．67％、15．87％，每株施215g钙镁磷肥则树高、胸径分别增加11．44％、7．83％；氮肥各水平间无差异，增产效果不明显；钾肥1、2水平间无差异，3水平可能过量，阻碍了肥效发挥。施肥能提高蓝桉生产的经济效益，较好的几个处理依次为6、9、2、10、3产出投入比值均大于对照。综合以上几个因素，N2P3K2为蓝桉幼林的最佳施肥方案。     

蓝桉人工纯林土壤肥力研究

本项研究历时４年,研究结果显示,营造蓝桉纯林会引起林地土壤肥力明显降低,有机质、全Ｎ、有效Ｎ、Ｐ、Ｋ、交换性Ｃａ２＋、Ｍｇ２＋等７项指标均直接受影响。蓝桉人工林,经造林初期林地施肥能提高其生长量,但不能阻止林地土壤肥力下降。由于施肥促进了林木的生长,故也加强了对土壤肥力的消耗。     

蓝桉工业用材林的施肥效应及地力变化研究

蓝桉工业用材林的施肥效应及地力变化研究在云南保山和富民红壤地区进行,历经8年,结果表明施肥对蓝桉人工林有明显的增产效果,并且经济效益显著.P肥是蓝桉增产的主要因素,施用P肥的处理生长量明显高于其他处理;有机肥对蓝桉生长有一定的促进作用;N肥对蓝桉高生长的促进作用与K肥相近,对径生长的促进作用略低于K肥;在有效K含量较高的地区,可以不施用K肥.在云南红壤地区培育蓝桉短周期工业原料林,可根据林地土壤情况将施肥量控制为基肥施普钙或者钙镁磷肥400～500g*株-1;追肥施尿素50～100g*株-1、硫酸钾0～100g*株-1,分两年平均施入.据监测,施肥可以有效地阻止土壤养分含量迅速下降.     

施P肥和外生菌根菌接种对蓝桉林产量和养分积累的影响

主要研究施P肥和接种外生菌根菌对蓝桉生长、生物量和养分积累的影响。在云南楚雄的试验表明：接种外生菌根菌只能在幼林期促进树木生长，3a后这种促进作用不显著。施P肥能在幼林期促进蓝桉树高和胸径的生长，但4．5a后这种促进作用也变得不显著。由于施P肥提高了蓝桉的保存率，所以也显著地提高了蓝桉林的生物量。低P处理时，树木保存率低，较大的生长空间促进了树木的后期生长，可能会导致施P肥对后期单株蓝桉树高和胸径生长作用不显著。施P肥还增加了树木N、P和K的养分积累量，提高了上述养分的利用效率。施P肥同时还明显增加了林下植被和林下凋落物P的积累量，但不能明显增加N和K的养分积累量。树木叶片和土壤分析结果进一步说明施P肥对蓝桉幼林作用明显。试验表现出接种外生菌根菌只能在低P情况下促进树木生长，不能在高P情况下促进树木生长的基本趋势。     

施肥对蓝桉幼林生长的影响

经５ａ研究结果表明,在省保山市石灰岩红壤区施肥能明显促进蓝桉幼林生长,肥效在１．５ａ时最大,９个施肥处理的树高、胸径平均增长３３．６９％、４８．３９％,造林后５ａ时,生长反应已经呈下降趋势,９个施肥处理的树高、胸径平均增长１６．４５％、１０．７１％。Ｐ 促进蓝桉增产的主要因素,每株施４３０ｇ钙镁磷肥的几个处理产好,Ｎ、Ｋ肥增产效果不明显,有机肥对蓝桉生长有促进作用。在９个施肥处理中,处理６（钙镁磷     

桉树人工林中期施肥试验研究

对尾巨桉2.5 a生间伐后的林分进行施肥试验.结果表明,间伐后施用适量的N、P、K肥有明显的增产效果.以每株施用磷酸二铵(N、P)750 g、氯化钾(K肥)90~270 g、硼砂(B肥)0~30 g,即每株施N135 g、P2O5338 g、K2O50~100 g、B 0~5 g的增产效果最好,优化配比为N:P2O5:K2O:B=1∶2.5∶0.37~1.11∶0~0.04.在肥料元素合理配比下,磷酸二铵、氯化钾和硼砂的总施肥量控制在850~950 g/株,以单质肥料测算,则N、P2O5、K2O、B有效养分总量应控制在520~575 g/株范围.以该施肥组合方案进行实施,施肥后2.5 a林分平均胸径、树高和材积年均生长量分别达3 cm、3.2 m和0.10 m3以上,比未施肥的林分分别提高190%~200%、268%~273%和400%~465%,可净增加收入7~8万元/hm2.中期施肥对提高林分生长量和经营经济效益显著.     

蓝桉组织培养的研究

用蓝桉（Ｅｕｃａｌｙｐｔｕｓｇｌｏｂｕｌｕｓ）离体芽器官诱导培养，分化形成丛生芽，年繁殖系数３￣（１２）。０．１～０．５ｍｇ／Ｌ的６－ＢＡ或０．５～０．８ｍｇ／Ｌ的ＫＴ诱导外植体（带节茎段）腋芽萌动的效果最佳，诱导率分别达８０．３％和８１．５％。１．５～２０ｍｇ／Ｌ的６～ＢＡ或２０～２．５ｍｇ／Ｌ的ＫＴ分别与０．５～１．０ｍｇ／Ｌ的ＮＡＡ组合，对于促进腋芽分化形成丛生芽及继代培养中芽的增殖具有最佳效果。培养基中的无机盐浓度、蔗糖含量对蓝桉试管苗的生根具有显著影响；ＩＢＡ促进蓝桉试管苗的生根。至目前为止，在１／２ＭＳ无机盐培养基＋ＩＢＡ１．２～１．４ｍｇ／Ｌ＋Ｓ５ｇ／Ｌ中诱导生根，生根率最高可达２６．４％。     

史密斯桉造林密度与施肥模式研究

针对史密斯桉造林密度与施肥模式进行了研究,对试验地设置3种造林密度作主区,4种施肥模式作副区。对17个月生史密斯桉的试验调查进行分析,结果表明：造林密度对树高生长量的影响差异不显著,而对胸径影响差异显著,适宜密度为2000株·hm^-2。施肥对史密斯桉幼树树高、胸径生长的影响极显著,不同的施肥模式对史密斯桉幼林生长的效果是：桉树专用肥>复混肥+微肥>复混肥+磷肥+微肥>复混肥+磷肥。     

桉树人工林生态效应研究进展

在发展桉树人工林的过程中,必须注重可持续性经营的思想,促进人工林产业生态化。从桉树人工林蒸腾耗水及对区域水分平衡影响的研究,桉树人工林的养分研究,桉树人工林化感作用(Allelopathy)研究三方面对我国的桉树人工林生态效应研究进行了总结。目前的基本结论:(1)桉树人工林耗水量由气候条件、立地状况和树木生长特性共同决定。通过与固氮树种混交或轮作、适当延长轮伐期、整地时尽量避免破坏植被、缩短林地裸露时间、保护林下枯落物、保留采伐剩余物等营林措施,可以提高桉树人工林在减少水土流失和涵养水源方面的作用。(2)20世纪90年代以前我国桉树人工林普遍存在地力衰退的问题,导致土壤肥力下降的主要原因是不合理的经营管理措施,机耕全垦导致土壤和养分流失十分严重;全树(含凋落物)利用导致养分循环不畅;不合理施肥导致元素之间的供给不平衡。早期种植的桉属树种凋落物少、热带土壤本身的脆弱性和降雨量集中也促成了地力衰退的发生。目前由于整地措施的改进、施肥量增大和元素间搭配更加合理、树种的改良和在桉树人工林内采集燃料的减少,桉树人工林地力衰退已经得到根本性的逆转。(3)部分学者在实验室高度浓缩的情况下,发现桉树同其它植物一样,有化感物质的存在。但自然条件下很难发生,而广东雨量丰富,桉树能同绝大部分林下植物共生。只要合理地经营桉树人工林,桉树人工林会产生经济效益与生态效益。     

毛竹林施肥效果研究

通过对毛竹林不同施肥种类和数量进行对比试验,研究结果表明：不同施肥种类和数量,竹林翌年出笋数、笋产量、新竹秆重等指标均显著或极显著高于对照区;各处理间新竹胸径没有显著差异.施肥能有效提高毛竹林的纯收入,其中以施用0.01 kg/株稀土＋0.25 kg/株复合肥效果最佳,可增加纯收入339.7元/667 m2.     

Fertilization in a Fourth Rotation Eucalyptus grandis Plantation with Minimal Management

ABSTRACT

Successive rotation and wood harvest of fast growing trees, like Eucalyptus grandis, can deplete soil nutrient pools. In these intensively used soils, productivity can decrease, and fertilization can be necessary to recover soil fertility. The aim of this work is to evaluate if fertilization with N and P increases tree growth and foliar nutrients in an Eucalyptus grandis plantation growing over a soil used for three rotations of this species. In the same experiment, both fertilization on seedlings and coppiced trees were evaluated. One and two years after planting, any fertilization treatment increased tree growth, even though coppiced trees had higher total height and DBH than replanted trees. Coppiced trees had lower specific leaf area, as well as lower N and P leaf concentration. The lack of promotion in growth due to fertilization can be explained by the inputs of nutrients from the harvest residues of the previous rotation. As residues were never burned in this site, its decomposition released a high part of nutrients necessary to sustain growth during the first two years. We conclude that in sites where residues were left on site and were not burned, nutrient availability is enough and so fertilization at establishment is not necessary. It remains to be determined if fertilization is necessary at mid or end rotation, in order to balance nutrients export with harvest wood.     

桉树人工林营养特性与施肥技术研究进展

对桉树人工林的养分需求规律、树体的营养诊断、施肥时期和施肥方式、施肥种类和施肥量等进行了探讨,建议应用计算机推荐施肥系统,构建基于3S技术的桉树人工林营养管理系统,应用营养诊断技术配制并施用桉树专用复合肥,进一步完善施肥技术.     

雷州半岛短轮伐期桉树人工林施肥技术合理性分析

根据短轮伐期桉树纸浆用材林不同林龄桉树（Eucalyptus）的树高、胸径、材积的生长特性,以及不同林龄桉树纯林土壤化学性质的特点,分析一个轮伐期内桉树纯林土壤养分变化,结果表明中林集团雷州林业局有限公司现有的施肥技术不尽合理,造林后第 2 年氮素缺乏,第 4 年磷、钾素不足,第 5年氮、钾素含量偏低,而第 3 年土壤基本元素含量相对偏高,因此以维持林地当前土壤肥力水平为目的,对林场现行的施肥方案提出了相应的调整建议,可有针对性地补充该生长阶段所缺乏的元素。     

蓝桉纸浆林综合培育技术研究

培育蓝桉纸浆林应重点考虑施肥。较好的栽培模式是撩壕整地加合理施肥 ,并将初植密度确定在 2 5 0 0～ 30 0 0株·hm-2 。从蓄积量、经济效益考虑 ,蓝桉在一个轮伐期内 ,可间伐 1～ 2次 ,最后保留木应为 5 6 0株·hm-2 左右。蓝桉作为纸浆用材 ,轮伐期确定为 7～ 8a较为合理     

Effect of Coriolus versicolor on physico-chemical properties of Eucalyptus globulus wood

Summary The purpose of this study was to determine the progressive changes in physical and chemical properties of Eucalyptus globulus wood under the action of a representative white rot fungus, Coriolus versicolor. Observations concerning the nature and relative effects on weight loss, hot water solubility, 1% sodium hydroxide solubility, Klason lignin, holocellulose, intrinsic viscosity and degree of polymerisation of holocellulose, pentosans, methoxyl value, neutral sugar composition and nitrobenzene oxidation products are discussed.The authors thank Dr. P. S. Rehill, the then Officer-in-Charge, Forest Pathology Branch, for valuable suggestions and providing facilities for decay experiments     

桉树近熟林追肥效果初探

传统的桉树经营措施一般只追肥到2-3a,本文对桉树4年生左右的近熟林追肥的效果进行了研究,追肥8个月后的结果表明追肥林比对照平均提高产量1.42m3/667m2,可实现纯利润278.02元/667m2;近熟期的追肥对不同的品种的增产效果不同,其中LH1增产1.78m3/667m2,U6增产1.50m3/667m2,W5增产0.96m3/667m2。追肥的增产效果说明,对近熟林追施肥是挖掘桉树速生潜力的有效技术措施。     

我国桉树人工林施肥现状、存在问题及对策

本文从桉树需肥特性及我国桉树主要种植区土壤肥力状况分析入手,着重论述我国桉树人工林施肥现状,并指出目前我国桉树人工林施肥中存在的主要问题,提出在桉树栽培中使用肥料等相应建议,为我国桉树速生丰产林的可持续经营提供科学施肥依据。     

Effect of thinning and fertilizer on the cellulose crystallite width of Eucalyptus globulus

An analysis of cellulose crystallite width, microfibril angle and wood density after the time of thinning (at 8 years) in straight vertical trees was undertaken in a 13-year-old E. globulus trial designed to assess the effect of thinning on tension wood formation. The most important effect was on cellulose crystallite width, which increased with thinning intensity and this was mitigated where fertilizer was applied at the time of thinning. Given the relationship between high crystallite width and tension wood occurrence the results demonstrate that heavy thinning of E. globulus at this age can contribute to tension wood formation. However, tension wood production may be significantly reduced where fertilizer is applied. This is possibly because increased diameter growth as a response to fertilizer application stabilises the stems and this is the mechanism by which trees cope with internal stresses that are generated from wind in destabilsed stands following thinning. In contrast, trees that respond poorly to thinning produce tension wood.     

Foliar nutrient retranslocation in Eucalyptus globulus

We measured patterns of change in concentrations and contents of nitrogen, phosphorus, potassium, magnesium and calcium in fully expanded leaves of young Eucalyptus globulus (Labill.) trees growing in a plantation in southeastern Australia, over a 12-month period beginning at the onset of spring. There was significant net retranslocation of mobile nutrients on a seasonal basis from green leaves, coinciding with continued growth and production of foliage. There was a close positive relationship between initial nutrient content (N, P and K) of the leaf and amount retranslocated, and a tight coupling between N and P retranslocated from leaves. Net retranslocation was significantly correlated with basal area growth increments. Artificial shading of leaves resulted in senescence and reduction in leaf mass. It also induced retranslocation of N, P and K from leaves of different ages and from different position in the canopy. Although the mechanisms underlying the effects of shading intensity on these changes were not elucidated, shading provided an experimental tool for studying retranslocation. Comparison of the results with published data for Pinus radiata (D. Don) grown in the same environment indicated a similarity between the species in patterns of change in foliar nutrient contents and in factors governing foliar nutrient retranslocation, giving rise to unifying principles.     

广西速丰桉树人工林二元胸高形数模型研究

以广西速生丰产按树人工林719块样地数据为基础,通过优选模型结构,以模型本身为权函数进行加权最小二乘法求解模型参数,研究建立了速生丰产按树人工林二元胸高形数模型。经检验,模型用于林分蓄积估计的总相对误差和平均相对误差均在±2．0％以内,小于规定的±3％;模型总体预估精度达99％以上,大于规定的97％;满足林业数表建模要求。