天然茶秆竹不同垦复措施的效果研究

对天然茶秆竹采取不同垦复措施后的出笋数、成竹数、成竹率进行统计分析,结果表明:(1)不同年度的天然茶秆竹采取相同的垦复措施,垦复效果一年比一年好;(2)茶秆竹林采取不同的垦复措施效果不同:采取劈山+全锄+施肥处理,2a出笋数10995株·hm-2,比其它2种措施提高15 5%～16 0%。成竹数7455株·hm-2,提高20 5%～23 3%;成竹率67 8%,提高4%～5 9%,明显高于其它2种措施;(3)经过劈山+全锄处理的茶秆竹发笋个数和新竹株数与劈山处理的差异不明显。     

不同施肥措施对红哺鸡竹生长的影响

红哺鸡竹是高产、优质的笋用竹种.试验中采取施用无机肥、生物有机肥、种绿肥与不施肥等不同措施,结果是采用A处理(劈山+全锄)和D处理(种绿肥)在发笋数、成竹数及平均胸径、平均竹高相差不大,而B处理(劈山+全锄+化肥)和C处理(劈山+全锄+生物有机肥)的效果明显优于A、D处理,特别是C处理(劈山+全锄+生物有机肥)对发笋数、成竹数及平均胸径、平均竹高等促进效果最好.为红哺鸡竹的丰产培育及绿色栽培提供了依据.     

野生茶秆竹林垦复改造试验研究

野生茶秆竹垦复改造措施的田间试验结果 ,不同垦复改造措施对次年出笋数量 ,新竹数量 ,平均胸径、平均高的影响高低、显著顺序为 :浅翻加施肥 >浅翻 >全锄、全劈 ,全锄与全劈间无差异 ,施肥可以明显增加新竹成竹率 ;对新竹总生物量 ,总竹秆鲜重 ,单株平均秆鲜重 ,鲜秆重占总生物量比值的影响高低的显著顺序为 :浅翻加施肥 >浅翻 >全锄、全劈 ,且全锄、全劈间无显著差异 ;对新竹总枝叶重的影响高低 ,显著顺序为 :浅翻加施肥 >浅翻 >全锄、全劈。试验结果表明 :不同垦复改造措施均为野生茶秆竹复壮的有效措施。野生茶秆竹改造效果优劣顺序为 :浅翻加施肥 >浅翻>全锄 >全劈     

残次毛竹林更新改造试验初报

采取对照、劈杂、深翻、施复合肥料、施饼肥5种技术措施,对残次毛竹林进行了人工更新改造。经过4个年度对毛竹林分出笋、成竹、胸径3个指标进行了观测调查,结果表明:不同人工改造措施总体上促进了毛竹林的生长;随着人工改造措施实施时间(次数)的延长,各年度间毛竹林分出笋、成竹均有极显著差异、胸径有显著性差异;各人工改造技术处理间出笋数差、胸径差异显著,而成竹数差异不显著。检验结果表明:不同的人工改造措施对毛竹生长的正效作用排列依次为施复合肥料施饼肥深翻劈杂对照。     

笋竹两用毛竹林不同经营措施效果比较

试验通过劈草清杂灌(A)、劈草清杂灌+松土扩鞭(B)、劈草清杂灌+深翻+施肥?3种经营措施对笋竹两用毛竹林的出笋数、成竹数、成竹率及生长量进行分析和对比,结果表明:不同经营措施对笋竹两用毛竹林的出笋数、成竹数、成竹率及生长量具有极显著影响;以劈草清杂灌+深翻+施肥?进行抚育的毛竹林经营效果最好,出笋数、成竹数、成竹率及生长量均超过(A)、(B)2种抚育措施.     

毛竹疏残林人工改造技术试验初报

采取对照、劈山清杂、全垦、施复合肥料、施饼肥5种技术措施,对毛竹疏残林进行人工改造。经过对毛竹林分出笋、成竹、胸径3个指标连续4 a的观测调查,结果表明不同人工改造措施总体上促进了毛竹林的生长;随着人工改造措施实施时间(次数)的延长,各年度间毛竹林分出笋、成竹、胸径3个指标均有极显著、显著性差异;各人工改造技术处理间出笋数差异极显著、胸径差异显著,而成竹数差异不显著。q检验结果表明,不同的人工改造措施对毛竹林生长的正效作用排列依次为施复合肥料>施饼肥>全垦>劈山清杂>对照。     

龙川县毛竹低产林不同抚育措施分析

对龙川县毛竹林开展调查研究,采取三种不同的抚育措施对低产林进行改造,连续5年跟踪调查,试验结果认为：拔山＋垦复＋施肥低改措施是有效并值得推广的毛竹低产林抚育改造措施,对促进毛竹林新竹萌发,提高成竹率和毛竹林的经济效益效果明显。     

如何提高低产油茶林效益

低产油茶林改造对象是指立地条件较好,坡度25度以下,郁闭度0.6左右,中壮龄植株占林分70%以上,基本株数每亩60~200株,常年亩产茶油4公斤左右,具有较大增产潜力的荒芜油茶林。油茶低产林改造主要技术措施有:一、垦覆翻土垦覆包括深挖、中耕和劈山,一般是三年一深挖,一年一浅锄。垦覆是油茶低产林改造最重要的技术措施,所有油茶低产林改造都必须以垦覆为基础,特别是已经多年未进行过人工抚育的油茶林。垦覆翻土以冬夏两季为好。冬季垦覆应该是深挖,一般为25~30厘米,并使土壤大块过冬。夏季垦覆采取的方法是浅锄。其深度一般为10~13厘米,以不伤…     

毛竹林不同抚育技术措施生长效果比较

试验于2014年11月至2017年6月上旬期间,对毛竹林采用不同抚育技术措施(A:全面锄草清杂+翻垦+施肥;B:全面锄草清杂+翻垦;C:全面锄草清杂;CK:不抚育)进行出笋成竹及新竹生长效果比较,结果表明:不同抚育技术措施对毛竹的出笋成竹及新竹生长具有极显著影响,以处理A的出笋成竹量及新竹生长量最高,平均春笋出笋数达965个/hm~2,平均成竹数达922株/hm~2、平均成竹率达95.5%,平均胸径达11.6cm、平均高达12.8m。     

不同低改措施对油茶低产林产量的影响研究

经过4 a的低改试验,总结提出了对油茶低产林增产效果较好的垦复方式为夏季穴垦并浅垦+冬季全垦并深垦;施肥组合为3月份施氮、磷、钾复合肥(氮磷钾21-6-13)750 kg/hm2+7月份施氮、磷、钾复合肥(氮磷钾17-17-17)750 kg/hm2+10月份施有机肥15 000 kg/hm2和氮、磷、钾复合肥(氮磷钾20-5-10)375 kg/hm2,综合改造措施是挖蓄水平台+清除杂灌+密林疏伐和稀林补植+整形修剪+截干萌芽和预植更新+高接换冠+垦复+合理施肥。     

不同抚育措施对撑绿竹笋、幼竹生长的影响

对水富县退耕还林地的撑绿竹进行了施用尿素和饼肥、中耕锄草等不同处理的比较试验。结果表明:施用尿素和饼肥比对照能提早出笋7~10 d,且成竹高度和胸径明显增大;而中耕除草效果不明显。     

煤矸石山立地条件与林业复垦研究——以山西统配煤矿为例

煤矸石是我国工业排弃数量最大的固体废弃物，它带来的危害是压占土地、破坏景观、污染环境。山西省作为能源重化工基地，煤矸石的堆积、污染问题尤为突出，改造任务异常艰巨。研究结果表明：煤矸石成山状堆积，仅表层１０ｃｍ左右有物理风化，下层很难风化；煤矸石山可蓄一定的水分，但地表高温，养分贫瘠，特别是自燃后的矸石强酸高盐，给植被恢复带来了极大的困难；大量煤矸石山的基本出路是进行林业复垦。其适用技术体系包括：①做好水保工程，保留地表黑色风化层；②引入先锋草种、树种；③薄盖土后直播；④加强施肥、病虫害防治等管理。     

Contributions of woody and herbaceous vegetation to tropical savanna ecosystem productivity: a quasi-global estimate

To estimate the relative contributions of woody and herbaceous vegetation to savanna productivity, we measured the 13C/12C isotopic ratios of leaves from trees, shrubs, grasses and the surface soil carbon pool for 22 savannas in Australia, Brazil and Ghana covering the full savanna spectrum ranging from almost pure grassland to closed woodlands on all three continents. All trees and shrubs sampled were of the C3 pathway and all grasses of the C4 pathway with the exception of Echinolaena inflexa (Poir.) Chase, a common C3 grass of the Brazilian cerrado. By comparing the carbon isotopic compositions of the plant and carbon pools, a simple model relating soil delta 13C to the relative abundances of trees + shrubs (woody plants) and grasses was developed. The model suggests that the relative proportions of a savanna ecosystem's total foliar projected cover attributable to grasses versus woody plants is a simple and reliable index of the relative contributions of grasses and woody plants to savanna net productivity. Model calibrations against woody tree canopy cover made it possible to estimate the proportion of savanna productivity in the major regions of the world attributable to trees + shrubs and grasses from ground-based observational maps of savanna woodiness. Overall, it was estimated that 59% of the net primary productivity (Np) of tropical savannas is attributable to C4 grasses, but that this proportion varies significantly within and between regions. The C4 grasses make their greatest relative contribution to savanna Np in the Neotropics, whereas in African regions, a greater proportion of savanna Np is attributable to woody plants. The relative contribution of C4 grasses in Australian savannas is intermediate between those in the Neotropics and Africa. These differences can be broadly ascribed to large scale differences in soil fertility and rainfall.     

不同经营措施对雷竹笋的营养品质效应

为探讨不同经营措施对雷竹笋营养品质的影响,在临安市三口镇雷竹林地设置6种不同施肥条件,同时进行覆盖与未覆盖两种处理.试验结果表明:有机肥与化肥混施有利于雷竹笋总糖、脂肪、淀粉的积累,而减少对灰分、粗蛋白的积累.雷竹林地采用覆盖技术后,改变了雷竹笋体内各类营养物质的分配,但对其总量则影响不大.     

THE CHECKING OF FOREST TREES BY HEATHER

Experiments on podzolized heather moor at Allerston Forest haveshown that a heather mulch applied around checked Sitka spruce(Picea sitcbensis Carr.), Norway spruce (P. abies Karst.), andLawson cypress (Cbamaecyparis lawsoniana Parl.), or more simplythe elimination of living heather by surface hoeing, producesimproved colour and vigour of the trees. It has also been demonstratedthat the addition of a nitrogenous fertilizer to checked Sitkaspruce can, at least temporarily, alleviate the condition ofcheck.     

Weed control measures in Christmas tree plantations of <Emphasis Type="Italic">Abies nordmanniana</Emphasis> and <Emphasis Type="Italic">Abies lasiocarpa</Emphasis> on agricultural land

Abies nordmanniana and Abies lasiocarpa, established for Christmas tree production in southwestern Norway (58°44′N, 5°38′E), were treated with different weed control methods, including chemicals, use of black plastic mulch, grass or clover as ground cover, living mulch and mechanical hoeing. Ground cover with black plastic mulching resulted in the best growth and quality in A. lasiocarpa; the least favourable treatment was when grasses were allowed to grow close to the trees. Unless measures were taken to remove this competing vegetation, the ground cover grew over the trees, smothering 94% of them. A. nordmanniana plants grew to the same height on plots with no weed control as on plots with thorough weed eradication. Stem diameter decreased on plots with ground vegetation compared to seedlings grown in the weed-free environment. The use of Trifolium repens as ground cover decreased height growth by 30% compared to thorough weed control. Both grasses and clover sown as living mulch, damaged the trees more than did natural weed vegetation.     

Forage production and nitrogen nutrition in three grasses under coconut tree shades in the humid-tropics

Reduction in forage production (FP) under trees in the humid tropics is well known, but information on how different levels of nitrogen (N) fertilizer influence FP under trees is meager. The present study reports effects of four N fertilizer levels (0, 60, 80 and 120 kg ha⁻¹ N) on net soil N mineralization rate (NMR) and soil moisture (SM), FP, shoot biomass/root biomass ratio (SB/RB), N concentration in SB, N uptake and nitrogen use efficiency (NUE) of three grasses [guinea (Panicum maximum Jacq.), para (Brachiaria mutica (Forssk) Stapf) and hybrid-napier (Pennisetum purpureum Schumach.)] under three canopy positions [under canopy (UC, representing high shade), between canopy (BC, representing low shade) and open] of coconut trees (Cocos nucifera L.) in a coconut based silvopastoral system in the humid tropical climate of South Andaman Island of India. The study was performed for two annual cycles (2005–2006 and 2006–2007). The hypotheses tested were: (1) FP would decline under tree shades, both in N fertilized as well as no N fertilized conditions, when SM was not growth limiting in the open. However, amount of decline in the FP would depend on grass species and intensity of shades i.e., higher was the shade greater would be the decline; (2) N fertilizer would increase FP under tree shades, but the increase depended on grass species, intensity of shades and amount of N applied. Amount of N applied, however, would not annul the shades effects when SM was not growth limiting in the open. The study revealed that the tree reduced light 59% under UC and 32% under BC positions, but the N fertilizer levels increased NMR by 11–51% under UC and 3–44% under BC positions compared to the open. SM did not differ across the canopy positions. Under all situations, FP of all grasses declined under UC (47–78%) and BC (18–32%) positions compared to the open; the decline was greater in Hybrid-napier than Guinea and Para grasses. Forage production of all grasses increased with N fertilizer increments under all canopy positions reaching 32 t ha⁻¹ dry matters for hybrid-napier at 120 kg ha⁻¹ N in the open. Both guinea and para grasses outyielded hybrid-napier grass under UC but not under BC or in the open. N concentration in the forage (SB) also increased as N fertilizer level increased. These observations support our hypotheses and suggest that forage production under coconut palms can be increased by the application of N fertilizer with both guinea and para grasses being more productive than hybrid-napier grass under the high shade. Where light conditions are better, hybrid-napier would produce more forage than the other species.     

Tree–grass interactions for N in Nothofagus antarctica silvopastoral systems: evidence of facilitation from trees to underneath grasses

Nothofagus antarctica forests in south Patagonia are usually used as silvopastoral systems but how grasses and trees compete for specific resources, such as nitrogen in these systems is unknown. To understand interactions between grasses and N. antarctica trees for N, an experiment with ¹⁵N labeled fertilizer was carried out comparing N absorption by grasses growing under trees (silvopastoral system) with an open site. Labeled ¹⁵NH ₄ ¹⁵ NO₃ fertilizer at 10 % atom excess was added in spring at both sites and ¹⁵N was measured in herbage, soil and trees every 30 days during the growing season. Soil was the component that containing the greatest amount of N and greatest ¹⁵N recovery. Grasses growing in the silvopastoral system absorbed almost double of the fertilizer applied than grasses in the open site (32.4 kg N ha^?1derived from fertilizer based on ¹⁵N recovery). Roots were also an important fate for N absorbed, representing 50 and 63 % of total ¹⁵N recovered in grass roots of open and silvopastoral sites, respectively. Trees absorbed 69 % less applied N than grasses in the silvopastoral system; being mainly allocated in small branches, sapwood and fine roots. Overall, ¹⁵N recovery was 65 % higher in the silvopastoral system (tree + grasses) than in the open site (grasses). Silvopastoral system made more efficient use of the ¹⁵N added. These results indicated that N. antarctica trees in the silvopastoral system may “facilitate” fertilizer N absorption of grasses by improving environmental conditions like water availability or by reducing competition for inorganic N between soil microorganisms and plants.