共查询到20条相似文献，搜索用时 718 毫秒
1.
2.
宽甸县是辽宁省板栗产业化生产的主要区域,目前宽甸县板栗产业生产存在的主要问题是品种优良化程度低。加快宽甸板栗基地建设,提高板栗产量质量和效益,必须实现板栗良种化栽培,实践证明,对现有板栗进行嫁接改良是加速宽甸县板栗产业基地建设的主要技术措施,适宜宽甸县栽培推广的主要优良品种有"辽丹系列板栗"、"辽栗系列板栗",嫁接改良的主要技术是皮下接、皮下腹接。 相似文献
3.
以大别山区2种典型的板栗林药模式板栗-苍术和板栗-天麻为研究对象,测定比较板栗套种苍术和天麻对林地小气候和土壤理化性质的影响。结果表明,板栗林下套种苍术和天麻后10 cm地温降低,板栗-天麻10 cm地温显著低于板栗纯林;林下气温和气温日较差降低;林下湿度有所升高,板栗-天麻的大气湿度稳定地高于板栗纯林;土壤容重板栗-天麻板栗纯林板栗-苍术,最小持水量板栗-苍术板栗纯林板栗-天麻,板栗-苍术土壤全效氮、全效磷、全效钾、有效氮、有效磷和有机质增加,板栗-天麻土壤全效氮、全效钾、有效氮、有效磷、有效钾含量降低。与套种天麻相比,板栗林下套种苍术有较好的生态效益。板栗林下套种天麻时,建议避免连茬种植,及时施肥补充地力。 相似文献
4.
进一步推进罗田板栗产业发展的思考 总被引：1，自引：0，他引：1
罗田是闻名全国的“板栗之乡”,是“全国板栗生产第一县”。全县板栗基地面积达到6．67万hm^2,常年板栗产量4万t,年板栗系列产值5．5亿元,板栗是罗田县域经济的支柱产业。笔者调查分析了目前罗田板栗产业发展的现状与存在的问题,针对性地提出了科学发展板栗产业的对策,旨在为进一步推进罗田板栗产业再上1个新台阶提供参考。 相似文献
5.
6.
一、易门板栗产业发展概况板栗是易门县的乡土经济林树种。易门板栗种植历史久远,在易门六街街道办柏树村马家箐有上百年树龄的板栗树至今仍在结果。易门板栗产业发展以"易门早板栗"品种选育成功和扩大种植进入新的发展阶段。"易门早板栗"是1986年易门县林业部门选育成功的地方板栗良种,包括"特早熟板栗"(7月底以前成熟)和"早板栗"(8月上旬成熟)两个品系。具有早实、早熟(比一 相似文献
7.
8.
《经济林研究》2014,(3)
为了了解板栗-农作物间作的土壤理化性质变化状况,对广西东兰县4种板栗-农间作模式(板栗-玉米、板栗-花生、板栗-黄豆和板栗纯林)土壤密度、孔隙度、持水量、pH值和养分含量进行分析比较。研究结果表明,不同板栗-农间作模式土壤理化性质存在一定差异,其中板栗-花生、板栗-玉米、板栗-黄豆和板栗纯林表层土壤(0~20 cm)密度分别为1.11、1.13、1.08和1.21 g/cm3,非毛管隙度分别为13.60%、11.36%、10.35%和9.62%,总孔隙度分别为54.04%、52.68%、53.73和50.42%;不同板栗-农间作模式按照土壤全N、水解N、速效P和速效K含量由高到低排列依次大致为板栗-花生、板栗-黄豆、板栗-玉米、板栗纯林。因此,板栗混作有利于改善土壤结构,提高土壤有效养分含量。 相似文献
9.
为探讨板栗脆片增香的工艺技术,将生板栗及蒸、煮后的板栗分别切成厚度1 mm、2 mm、3 mm的板栗片,将板栗片在5个温度(160℃、180℃、200℃、220℃、230℃)进行不同时间的烘烤,再通过感官评定,研究板栗脆片的增香增色效果。结果表明:3种不同处理方式下,煮后烘烤的板栗片的增香增色效果最好,蒸后烘烤的板栗片次之,生板栗片烘烤后的效果最差,且煮后3 mm厚度板栗片在220℃、230℃烘烤25～30 min能达到最佳增香增色的效果。 相似文献
10.
11.
In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length (SRL) of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nu-trition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches. 相似文献
12.
全国杉木家系区域试验研究 总被引：1，自引：0，他引：1
湖南省林科院先后于 1984年春、 1989年春两次参加全国杉木家系区域试验。方差分析表明 :提供家系的种子园之间以及种子园内家系之间各主要数量因子存在显著差异。对样本观测值进行标准化变换主成分分析 ,求出遗传综合指数 ,再聚类分析评价 :湖南靖州、江西赣南、广西柳州、贵州东南、福建三明、广东曲江种子园提供的家系生长有明显优势。 相似文献
13.
香榧细小卷蛾Lepteucosma torreyaeWu et Chen是危害香榧的主要害虫之一,在浙江省绍兴市1 a发生2代,以老熟幼虫在枯枝落叶中做茧越冬,翌年2月中旬化蛹,3月上旬成虫羽化并产卵,3月下旬第1代幼虫孵化,5月中旬化蛹,5月下旬成虫羽化,6月上旬产卵,6月中旬第2代幼虫孵化,11月上旬开始越冬。在第2代幼虫期,使用1.8%阿维菌素乳油、5%抑太保乳油、2%阿维苏云制剂、35%吡虫啉乳油及20%杀灭菊酯乳油等5种药剂10个浓度进行喷雾防治试验,施药9 d后,防治效果均达到100%。 相似文献
14.
Transverse swelling and its anisotropy in hinoki (Chamaecyparis obtusa) in several kinds of organic liquids and in water were investigated by means the replica method. There was more cross-sectional swelling of cell walls and cell wall thickness in earlywood than in latewood. Marked swelling toward cell lumens was observed in wood swollen in liquids that had higher swelling potentials than water. This suggests that the swelling of cell walls in these liquids is much greater than the external swelling. Feret's diameters of the cell lumens were reduced by swelling in all the observed cases except in the tangential direction of earlywood, suggesting that cell walls swell to a much less extent in width than in thickness. Deformation of cell shapes caused by the tensile force from the latewood were observed in the earlywood and in the transitional region from earlywood to latewood. When swollen in water, transverse swelling anisotropy caused only by the swelling in cell wall thickness were calculated to be 1.2 for the whole region over an annual ring and 1.4 for the earlywood. These values could not account for the external swelling anisotropy of 2.1. Considering obvious deformations of cell shapes in the earlywood and in the transitional region, we conclude that the interaction between earlywood and latewood is one of the prime factors contributing to the transverse swelling anisotropy of coniferous wood.Part of this report was presented at the 48th Annual Meeting of the Japan Wood Research Society, Nagoya, April 1998 相似文献
15.
Thomas Zumbrunnen Gianni B. PezzattiPatricia Menéndez Harald BugmannMatthias Bürgi Marco Conedera 《Forest Ecology and Management》2011,261(12):2188-2199
Understanding the factors driving past fire regimes is crucial in the context of global change as a basis for predicting future changes. In this study, we aimed to identify the impact of climate and human activities on fire occurrence in the most fire-prone regions of Switzerland. We considered forest fires, land use and meteorological data over the period 1904-2008 in the neighboring mountain cantons (states) of Valais and Ticino, which are characterized by distinct climatic regimes.The presence/absence of fire ignitions was analyzed using the Nesterov ignition index (as a proxy for fire weather), road density (for ignition sources), livestock density (for biomass removal), and change in forest area (for fire-prone abandoned agricultural areas).We found that fire weather played a key role in fire occurrence in both regions. Road and livestock densities had similar influences in the two cantons. However, while the increase in forest area was well correlated with fire occurrence in Ticino, no such correlation was evident in Valais, probably because land abandonment and forest cover change have been less extensive there. Our findings emphasize the non-linear nature of the relationships between fire occurrence and anthropogenic drivers, as we found thresholds above which road density was no longer correlated with fire occurrence. This implies that the projected future increase and spatial concentration of the human population may not result in a further increase in fire risk in intermediately to densely populated areas in both cantons.The driving factors behind fire activity differ slightly in the two cantons, in particular with increasing forest area enhancing fire occurrence in Ticino but not in Valais. These differences should be taken into account when assessing future fire risk, especially in Valais where the potential for an increase in the fire-prone area is still high. Fires are likely to become more frequent in a warmer climate, but future fire activity may develop differently in the two cantons. This should be taken into account when planning optimized fire prevention measures. This case study should help to better understand fire activity in highly populated regions where fire activity is still moderate but might markedly increase under a projected more fire-prone climate. 相似文献
16.
17.
北京八达岭植物群落多样性特征分析 总被引：5，自引：0，他引：5
根据34个样地的调查资料,分析了该地区森林植物群落物种多样性的特征:群落内各层物种丰富度指数的大小为草本层>灌木层>乔木层;多样性指数的大小为乔木层<灌木层和草本层。灌木层与草本层的多样性指数随林分郁闭度变化而变化,在林分郁闭度为25%的侧柏黄栌混交林中,灌木层的多样性指数和丰富度指数小于草本层;在郁闭度53%的杂木林中,灌木层和草本层的多样性指数接近;在郁闭度53%以上的各个群落内,草本层的多样性指数和丰富度指数基本上都大于灌木层。人工林中的物种多样性变化多样,明显低于天然林,林分层次单一,更新不良,缺乏灌木层和地被植物,生态系统很不稳定。 相似文献
18.
IntroductionDuringthepasttwodecades,studieshaverevealedthatgrowingash(Fnainusmandshurica)andlarch(LarlksPP.)togetherinaproperwaycanincreasetheproduc-tivityQfthestandsI"'}'-'].Theyieldimprovementmechanismsattributetotwoaspects,i.e.,theabovegroundandundergr… 相似文献
19.
皆伐方式对小兴安岭低质林土壤呼吸的影响 总被引：2，自引：1，他引：1
针对小兴安岭低质林分,采用不同的皆伐方式,利用LI-8100碳通量自动监测系统在春、夏、秋、冬4个季节对低质林分土壤呼吸进行观测,运用统计分析的方法,分析皆伐方式对土壤呼吸的影响和不同皆伐方式的土壤呼吸产生差异的原因.结果显示:试验区土壤呼吸夏季最大,冬季最低.春季和秋季因土壤温度和湿度差异不大使土壤呼吸相差较小;对于水平带同一条皆伐带,土壤呼吸并无显著性差异,并且不同的带宽对土壤呼吸的影响也不显著;垂直带随海拔升高土壤呼吸呈现波动性,总体趋势随海拔升高土壤呼吸逐渐降低,但是差距较小;水平带、垂直带和林窗的年土壤呼吸量分别为1.184,1.426,1.179 kgCO2·m-a-1,垂直带最高,水平带次之,林窗最低.影响垂直带土壤呼吸的关键因素是土壤温度,林窗则是土壤湿度,而水平带土壤温度和湿度的条件则介于垂直带和林窗之间.这说明在不同的皆伐方式条件下,影响土壤呼吸的关键因素并不完全相同. 相似文献
20.
《Journal of Sustainable Forestry》2013,32(2-3):115-127
Abstract Seasonal behavior of vascular cambium and development of secondary xylem were studied in the 2-3-years-old branches of Azadirachta indica A. Juss. (Meliaceae) growing in moist deciduous (MDF), dry deciduous (DDF) and scrub land (SF) forests of Gujarat State. Development of xylem began with the sprouting of new leaves in January in both MDF and DDF. Xylem production culminated in July in MDF whereas it reached peak in April and July in DDF. Cambial cells ceased to divide with the maturation of leaves in November and October in MDF and DDF, respectively. Mature xylem and phloem derivatives surrounded the cambium in December in MDF and November in DDF. Radial growth in the branches of trees growing in SF was found continuous throughout the year with peak cambial activity in April, July and November. In all the three forests, maximal radial growth was encountered in July when the rains were heavy. Cambial activity and xylem development showed significant correlation with the phenology of the trees in MDF and DDF whereas cambium was found active throughout the year and no correlation was found between the cambial activity and phenology in SF. 相似文献