整地施肥对尾叶桉萌芽林生长影响的研究

通过开展整地施肥对尾叶桉萌芽林生长影响的研究，结果表明，全垦、带垦和穴垦3种整地方式对尾叶桉伐桩萌芽率、直立/优势萌芽余数及萌芽林树高和胸径生长有一定影响，但不明显；整地加施肥(全垦 施肥、带垦 施肥和穴垦 施肥)比单整地不施肥处理(全垦、带垦和穴垦)萌芽率提高5％左右；直立／优势萌芽余数整地加施肥处理在4．6—5．2条/桩之间，比单整地不施肥处理的平均多2条/桩左右；27个月生时，整地加施肥比单整地不施肥处理萌芽林的树高分别提高67．2％，60．7％和85．3％，胸径提高28．3％，25．7％和10．7％。     

整地对桉树人工林生态效益的影响

为了探讨整地方式对桉树林分生长和林地生态效益的影响,在3种整地方式下的尾巨桉林地分别设置样地和样方进行调查分析,结果表明：机械带垦和炼山全垦的尾巨桉林分生长均较人工穴垦快,炼山全垦的尾巨桉林下植被生物多样性最差,机械带垦的林地土壤有机碳含量最大,炼山全垦林地表层(0~40 cm)土壤含水量最高,人工穴垦林地深层(40~80 cm)土壤含水量最高。     

3种整地方式下尾巨桉林分生物量动态及其与土壤水分的关系

对3种整地方式下的尾巨桉林分生长和林地土壤水分进行了监测,通过分析各林地的林分单株平均生物量及林地土壤水分的变化,探讨二者的相互关系,以期为合理评估整地对尾巨桉林分生长和水分利用效率的影响提供科学依据。研究结果表明：随着林龄的增长,3种整地方式下尾巨桉林分单株总生物量和各器官生物量均呈增加趋势,其树干和树根所占比例逐渐增加,而树枝和树叶所占比例呈减小趋势。在幼龄期(16个月之前),全垦条件下的尾巨桉林分生长量最大,18个月后带垦的林分生长量最大;3种整地方式下的尾巨桉林地土壤水分的季节变化格局相似,与天然降水分布基本保持一致。3种整地方式中穴垦尾巨桉林地土壤有较高含水率且显著大于全垦和带垦的(P<0.05),全垦与带垦之间差异不显著;3种整地方式下尾巨桉林分单株平均生物量与耗水量之间均呈显著正相关,利用3块林分单株平均生长量及对应时间的耗水量得到了尾巨桉林分单株生长量与林分耗水量的拟合方程。     

3种整地措施下尾巨桉幼林生长及土壤有机质变化特征研究

对不同整地措施下尾巨桉幼林林分生长及土壤有机质变化研究表明：炼山全垦与带垦措施下林分平均地径极显著大于穴垦,但炼山全垦与带垦之间地径差异不显著;炼山全垦措施下的林分平均树高极显著高于带垦与穴垦;而林分蓄积量则为炼山全垦＞带垦＞穴垦。炼山全垦整地后,土壤有机质在表层土壤以下10~20 cm或20~30 cm均有不同程度的增大。土壤有机质含量在造林后1 a时3种处理间的差异不显著,但造林后1.5 a后发现炼山全垦有机质含量极显著优于带垦和穴垦,其次为带垦,穴垦最差。从目前来看炼山全垦的生长及土壤有机质含量占有较大优势。     

牛坡荒山不同整地方式及施肥对杉木幼林生长的影响

通过对牛坡荒山采用穴状整地、全垦整地2种不同整地方式和施肥与不施肥2种施肥处理进行试验发现,不同的整地方式及施肥处理对杉幼林生长影响较大。其中全垦整地施肥对杉木幼林树高、胸径的生长与穴状整地施肥、穴状整地不施肥均存在极显著性差异;穴状整地不施肥与穴状整地施肥对杉木幼树树高的生长存在显著性差异,对杉木幼树胸径的生长无显著性差异。全垦整地造林后第二年进行施肥,对杉木幼树树高及胸径的生长均有明显的促进作用;穴状整地造林后第二年进行施肥,对杉木幼树树高的生长有促进作用,但对胸径生长的促进效果不明显。结果表明:全垦整地施肥处理效果最好,且与穴状整地施肥、穴状整地不施肥2种造林方式相比,全垦整地施肥对杉木幼林生长量的影响均达到了极显著水平。     

杉木适度的整地方式

我省杉木造林整地用工量投入一般占轮伐期总投入的20-50％。不少人以为，全垦整地效果优于带垦、块垦和穴垦，大穴整地优于中穴、小穴整地，因而追求全垦大穴整地方式。最近，省林科所贺果山等入对绥宁、会同、桂阳等地不同立地8种整地方式杉木生长状况进行了调查研究，发现对于杉木这种浅根型树种而言，整地只对根系分布有直接促进效应，对树高、粗和材积生长仅有一定的早期促进作用。不同的整地方式对杉木生长的促进只有在较差的土地条件才有些微差别，在上等土地上基本没有反应。另有报告指出，在20度以上坡地进行全垦整地将引起严重的水…     

整地方式对杉木生长进程和土壤肥力的动态影响

通过不同整地方式对杉木生长进程和土壤肥力影响的动态研究,结果表明：整地方式对杉木幼林生长有显著影响,４～１４年生影响较大,１４年生后生长差别减小以至消失。不同整地方式在整地初期对土壤物理性质的改善作用表现为全垦＞带垦＞穴垦,整地后一年土壤理化性状指标较整地初期下降,并呈现穴垦＞带垦＞全垦的态势,至成林阶段土壤肥力受整地方式的影响已不显著。     

良种桉撩壕整地造林长势喜人

桉树生长的快慢很大程度取决于整地。良种桉(指尾叶桉、巨桉、柳桉、邓恩桉以及巨尾桉、尾巨桉、柳窿桉、雷林一号桉、柳州、横县的柠檬桉、山口83002号窿缘桉等)在我区主要栽培于平原台地和低丘地区。整地多为机耕、全垦挖大坎。而来宾县根据本县多为低山和丘陵,不适宜搞机耕的实际情况,采取撩壕整地造林,收到了良好的效     

杉木人工林不同整地方式对水土保持和幼林生长的影响

对南方山区现行三种整地方式的水土保持作用和杉木幼林的生长效果进行了连续６年的试验,结果表明：在正常情况下,各种整地方式的水土流失均轻微,年土壤流失量：全垦大于水平带垦大于自然对照区;年迳流量：水平带垦大于自然对照区大于全垦大于穴垦;年迳流量是年土壤流失量的２７２～７０７倍,而土壤流失中的养分损失,却是迳流中养分损失的９６倍左右,所以要维护地力,保土比保水更重要,三种整地方式的幼林生长的差异不很显著;单位面积用工量以穴垦最小。综合考虑,在坡度较大,土壤肥沃,劳动力紧张的南方地区,宜推广水保效果好,整地用工少,幼林生长良好的穴垦整地方式。     

海南岛西部地区桉树速生丰产林优化栽培模式研究

对在海南岛儋州林场实施的桉树速生丰产林栽培模式研究进行了总结。尾叶桉、刚果号桉施肥与株行距配置试验结果表明:施肥对幼林期尾叶桉、刚果号桉生1212长均有极显著的差异影响,不同的施肥配比和施肥量对尾叶桉生长的施肥效果是:B2 N0P150K160> B4 N90P200K160 >B3 N90P150K160> B1 N0P0K0(对照);对刚果号桉的效应是:12A3 N90P150K160> A4 N90P200K160> A2 N0P150K160> A1 N0P0K0;在相同的密度下不同的株行距配置方式对尾叶桉、刚果号桉的生长无影响,差异不显著。年生刚果号桉整地、密12312度与施肥试验结果表明:整地、施肥对家系和无性系的树高、胸径生长和胸径生长有影响,且差异极显著;密度仅对刚果号桉无性系胸径生长有影响且差异显著。三因素对12刚果号桉生长的影响程度为:整地>施肥>密度。—年生的四种人工林优化栽培模1236式分析结果表明:在同一立地类型,相同的栽培抚育管理措施下,选择适宜的良种是确保人工林实现丰产的关键;同一立地类型相同的栽培抚育措施下,刚果号桉行间间种12绢毛相思比间种大叶桃花心木生长量高;粗果相思在海南岛西北部的儋州地区发展潜力比马占相思大。     

Fertilization×genotype interaction in Pinus radiata open pollinated families planted in three locations in Galicia (NW Spain)

A Pinus radiata progeny trial was established in 2003 on three low fertility sites in Galicia to study the relevance of genotype×fertilization interaction. At each site, twenty seven open pollinated families derived from plus trees selected in mature plantations in Galicia (NW Spain) were planted under 9 fertilization treatments following a split-plot design. One year after planting, P and Mg fertilization significantly increased height growth whereas N did not affect or even significantly reduced height growth. Fertilization×site interaction was not significant indicating parallel responses to fertilization in the three sites. Fertilization × genotype interaction was significant in only one site, suggesting some genetic variation in the nutrient use efficiency among the studied genotypes. However, the lack of a significant interaction in the other two sites, and the lack of consistence among the genotypic stability in relation to fertilization across sites, hinder the possibility of breeding in relation to the nutrient efficiency of the genotypes. Indications for further research are given.     

整地施肥对I-69杨人工林生长效应的研究

在淮北平原宿县,通过大穴整地、施肥改良砂姜黑土、营造Ⅰ-69杨的五年试验证明,大穴整地当年效应明显(径、高增长19.8%、91.8%);头二年肥效不显;第三年起N肥、有机肥、N×有机肥交互作用效应极显著(材积增加77%),施P+K肥效应较差,N+K肥和N+P肥经济效益较高,投入/产出为1/6.22和1/3.78;材积增加60%和58%。整地加施肥综合效益明显,有效施肥占综合效益85.1%～88.8%。     

Phenological responses of juvenile pecan and white oak on an upland site

Pecan (Carya illinoiensis) and white oak (Quercus alba) produce multiple products and wildlife values, but their phenological responses to N fertilization have not been well characterized. We compared tree growth at planting and for six consecutive growing seasons during establishment (2003–2008, Test 1), and determined if phenology of budburst, leaf area index (LAI), quantum yield of photosystem II (Fv/Fm), radial growth, and total chlorophyll concentration (a, b) responded to poultry litter fertilization supplying 0, 50, and 100 kg ha^?1 N (2010–2012, Test 2) in a mixed-species orchard on an upland site near Booneville, Arkansas. Species did not differ significantly in height in Test 1. Budburst was 9 days earlier for white oak than pecan in 2010. Budburst for both species could be predicted by accumulating chilling and forcing units throughout the dormant season. Maximum predicted radial growth was comparable for pecan (2.19 mm) and white oak (2.26 mm), and peaked 28 days earlier for white oak (3 June) than pecan (1 July). White oak LAI generally exceeded that of pecan during the growing season. Senescence began about 27 October regardless of species, and was better characterized by decreasing Fv/Fm or total chlorophyll concentration than LAI. Phenology was generally not responsive to N fertilization, perhaps because of adequate soil and foliar N. The study provides additional information on growth responses of these high-valued species to supplemental fertilization on an upland site.     

不同造林因子对湿地松成活率和生长的影响

为了调查不同造林因子对湿地松成活率和生长的影响,文章从施肥方式、立地选择、林地小气候、土壤质地、种苗类型和苗木质量等方面对湿地松造林成活率及其生长量进行了试验分析,结果表明:保持土壤中合适的水分是提高湿地松成活率的关键,合理施肥,立地条件优越,小气候温暖湿润,土壤质地良好,容器苗和壮苗造林均能提高湿地松的成活率及树高、地径的生长量,因此栽植湿地松时应尽量选择自然条件优越的地类。如果条件允许可施基肥改善土壤营养状况,在干旱贫瘠的土壤上种植湿地松时,应采用容器苗,以提高苗木成活率和生长量。     

Fertilizer/site interactions on the growth and foliar nutrient levels of Eucalyptus grandis

This paper examines some of the relationships between site, fertilizer type and foliar nutrient levels with regard to growth responses of Eucalyptus grandis (Hill ex Maid.) in order to optimise fertilizer recommendations and characterize their effect on tree growth. Six comprehensive fertilizer trials, employing confounded factorial designs, were laid out over a number of years on six sites in Natal and Zululand, covering a wide range of environmental conditions. Experiments were assessed and compared at 4 years of age in order to control within-block variation of site factors. The major growth responses were to N and/or P, N only being suitable on sandy soils low in organic matter. Topsoils very high in mineralizable N responded to applications of P only. Sites with moderate amounts of organic matter required both N and P. Potassium generally had a depressive effect. Foliar values agreed well with responses to fertilizers, and were useful in characterizing sites and determining optimum application levels. The improvement in yield as a result of fertilization was relatively greatest on poor sites. However, there was a trend for the response in absolute terms to increase with site quality. For fertilizer recommendations to be optimized, there is a need for sites to be classified in terms of their soil water availability and the organic-matter content and texture of the topsoil. As improvements in growth increase with time, they are probably due to changes in root development and structure, rather than overall nutrient status. Thus, fertilizing must be viewed only as an integrated part of establishment practices, including the condition of nursery stock, site preparation and weeding.     

不同氮素施肥方法对尾巨桉苗期生长和光合生理特性的影响

采用3种不同的氮素施肥处理(平均施肥、直线施肥和指数施肥)对尾巨桉苗木进行施肥处理,结果显示：指数施肥获得的苗木苗高和地径均大于其他施肥处理;指数施肥下尾巨桉苗木的叶、茎、根和地上部分干质量和整株生物量均显著大于其他施肥处理,指数施肥获得了更多的苗木生物量;3种施肥处理下,指数施肥的苗木净光合速率 Pn、气孔导读 Gs 和蒸腾速率 Tr 均为最大值,且显著大于其他处理。因此,3种施肥方法中,指数施肥方法最利于尾巨桉苗木的生长和光合作用。     

DRIS-based fertilization efficiency of young hybrid poplar plantations in the boreal region of Canada

In order to maximize early growth and establishment of planted hybrid poplars in the boreal region of Eastern Canada, growth response of four clones to fertilization was tested in two plantations. The first two fertilization treatments were based on Diagnosis and Recommendation Integrated System (DRIS), a method based on nutrient ratios: DRIS I was based on previously established norms from a study that had been conducted in the same area, and DRIS II was based on DRIS norms developed from hybrid poplars in northern Ontario, Canada. Nutrient status and growth of trees under these 2 treatments were compared to unfertilized trees and to trees under standard (STD) fertilization treatment (40 N–20P–20 K). Leaf nutrient concentrations and DRIS indices showed that fertilization treatments, and especially DRIS I corrected N deficiencies but failed to correct P deficiencies. Fertilization increased volume relative growth rate by 7.51, 4.76 and 13.25 % on average at the agricultural site for DRIS I, DRIS II and STD treatments respectively, compared to no fertilizer application. At the forest site, fertilization treatments based on DRIS indices (DRIS I and DRIS II) increased growth rates (6.67 %) slightly more than the standard treatment (5.80 %). Overall, although DRIS-based fertilization treatments generally increased growth rates, they were often equal to or less efficient than the STD treatment, and may not be as practical as using a standard fertilization recipe.     

Modeling mid-rotation fertilizer responses using the age-shift approach

Growth and yield modelers have incorporated mid-rotation fertilizer responses by: modifying site index; developing new models to include fertilizer responses directly; using multipliers or additional terms to scale existing models. We investigated the use of age-shifts to model mid-rotation fertilizer responses. Age-shift prediction models were constructed from 43 installations of a nitrogen (0, 112, 224 and 336 kg ha⁻¹ elemental) by phosphorus (0, 28 and 56 kg ha⁻¹ elemental) factorial experiment established in mid-rotation loblolly (Pinus taeda L.) pine stands in the southeastern US. Age-shifts for dominant height and basal area increased with time after fertilization, to a maximum and then either remained fairly constant, or declined. The initial rate of increase, maximum age-shift and decline were functions of the rate and combinations of fertilizers applied, as well as stand density and age at fertilization. Volume age-shifts increased linearly throughout the 10-year measurement period for most treatments with the rate of increase being a function of the elements applied, stocking, site index and age at fertilization. A mid-rotation fertilizer application of 224 and 28 kg ha⁻¹ elemental N and P, respectively, resulted in age-shifts of 1.1, 1.9 and 2.4 years for dominant height, basal area and volume, respectively, 10 years after fertilization. The age-shifts were incorporated into growth and yield models.     

Effects on stem growth of Scots pine 33 years after thinning and/or fertilization in northern Sweden

Thinning and fertilization are two common and important stand treatments in forest management. In terms of area treated, thinning is the single most common form of stand treatment. The extent of forest fertilization on the other hand, has varied widely in recent decades and is currently not very common. Thinning is done primarily to promote stand properties while fertilization is done to increase growth before future final felling. After thinning stands of Scots pine, overall growth decreases, while growth of residual trees increases. An experiment was established outside Vindeln in northern Sweden where the long-term growth effects after thinning and/or fertilization were evaluated after 33 years. Experimental set-up was a randomized block design including 12 replications of four treatments. Treatments were control, fertilization, thinning, and thinning and fertilization combined. Thinning decreased overall and annual volume growth ha^?1, and increased green crown size and diameter growth at breast height (1.3 m, DBH) for the individual trees. No positive growth responses to fertilization could be seen after 33 years. In summary, this study showed that thinning can have long term effects on the growth of a Scots pine stand in northern Sweden. Possible reasons for the lack of positive response following fertilization are discussed.