浙江毛竹林分非空间结构特征及其动态变化   总被引：1，自引：0，他引：1  

刘恩斌  施拥军  李永夫  周国模  杨东 《林业科学》2013,49(9):1-7

利用2004与2009年浙江省两期森林连续清查毛竹样地数据,应用因子分析、聚类分析、相关分析、多元方差分析及核密度估计方法,采用7个指标(样地生物量,样地株数,林分平均胸径,1,2,3和≥4度竹所占比例)描述毛竹林分非空间结构特征。结果表明:毛竹林分非空间结构特征的主导因素依次为年龄结构因子、样地生物量因子、林分平均胸径因子;浙江现有毛竹林老龄化问题较突出,林分中各龄级所占比极不合理,现有经营措施存在较大缺陷,从而使林分生产力衰退;样地株数较少时,林分平均胸径与样地株数几乎没有相关性,但随着样地毛竹株数的增加,表现出一定的负指数关系;影响毛竹林分生物量的主要因素依次是样地株数与林分平均胸径;7个指标中除3度竹所占比例没有显著差异外,其他指标都存在显著差异,使得毛竹林分非空间结构(由7个指标构成)在2004年与2009年存在显著性差异;平均胸径小于8.7 cm的林分随着毛竹的生长所占比重在减少,而平均胸径大于8.7 cm的林分在增加,这也说明2009年林分平均胸径比2004年显著增大,样地株数和林分生物量与林分平均胸径有类似的趋势。研究结果对毛竹林的可持续经营与固碳功能的提高有一定的参考价值。  相似文献   

The Roles of Climate Variability and Habitat Heterogeneity in Structuring a Forested System: An Integrated Accumulation Function of Species Richness     

R. Talbot Trotter III  Thomas G. Whitham 《Journal of Sustainable Forestry》2013,32(8):721-735

As forested systems are impacted by both natural and anthropogenic factors such as climate change, the biodiversity supported by those forests is likely to change. Quantifying that change, however, remains a difficult task due to variations in the sizes and conditions of forested systems. Species accumulation curves are a commonly used tool to scale estimates of species richness and provide an avenue for comparing biodiversity among habitats through rarefaction. However, we found that the ranked biodiversity among forested systems depends on the sample unit used, and there is a need to integrate landscape heterogeneity in spatially scaleable estimates of biodiversity. Both of these biodiversity assessment issues can be addressed using a new approach we term the Integrated Accumulation Function (IAF), a method based on combining component species accumulation curves. Using this approach on communities of canopy arthropods found in pinyon pine forests in the southwestern United States, we found three major patterns. First, in small stands, trees growing under low environmental stress support the greatest species richness. Second, when stands are large, stands growing under higher environmental stress support greater species richness, and species richness is resilient to change over a broad range of the stress gradient. Third, there are threshold levels of stress at both ends of the stress spectrum beyond which species are rapidly lost. This analysis reveals unexpected patterns and suggests that conservation practices should consider the inclusion of forests growing under suboptimal conditions to maximize the preservation of biodiversity.  相似文献   

6种植物源农药对竹斑蛾幼虫的毒力及应用分析   总被引：1，自引：1，他引：0  

黄健韬 《世界竹藤通讯》2019,17(5):40

为筛选有效控制竹斑蛾（Artona funeralis）幼虫的植物源农药,选用6种植物源农药开展室内毒力测定和林间防治效果分析。结果表明：6种植物源农药对竹斑蛾幼虫均有良好的致死作用。参试的植物源农药以1.2%烟碱·苦参碱乳油和1.5%苦参碱可溶液的毒力较强,0.4%蛇床子素乳油的毒力较弱;4%鱼藤酮乳油、1.2%烟碱·苦参碱乳油、0.4%蛇床子素乳油、1%苦皮藤素可溶液、碧绿1%苦参碱和1.5%苦参碱可溶液对竹斑蛾幼虫的LC₅₀分别为0.826 mg/L、0.596 mg/L、1.016 mg/L、0.962 mg/L、0.811 mg/L和0.612 mg/L;林间施药4 d后,6种植物源农药的防治效果均超过90%;最佳田间施药浓度为：1.5%苦参碱可溶液和1.2%烟碱·苦参碱乳油均为1 500倍液,碧绿1%苦参碱和4%鱼藤酮乳油均为1 200倍液,0.4%蛇床子素乳油和1%苦皮藤素可溶液均为1 000倍液。参试的植物源农药对竹斑蛾幼虫的防治效果良好,可用于生产上防治竹斑蛾幼虫。  相似文献   

昭通市毛竹防护型经济林丰产培育试验研究     

白祖云  李正银  丁永平  曹安江  杨梅 《林业调查规划》2019,(2):127-130,134

为提高毛竹林的经济效益,巩固退耕还林成果,促进群众脱贫致富,针对昭通市毛竹林经营管理粗放的现状,通过密度调控和覆盖、调整竹笋采集时间等技术措施,试验探索毛竹防护型经济林丰产培育技术。结果表明,采用相应技术措施后的毛竹林比未经采取措施的毛竹林竹笋笋芽出土时间提前30 d左右,竹笋产量增加93.95%～125.54%,毛竹的平均粗度增加15.29%～28.89%。  相似文献   

伊春地区宽叶蓝靛果人工栽培试验     

张巍  李妍  高智涛 《林业科技》2019,(1):32-34

在伊春地区进行宽叶蓝靛果人工栽培试验的结果表明,宽叶蓝靛果扦插苗对该地区自然因子适应性较好,造林当年苗木生长高峰出现在8月中旬,第二年生长高峰提前至6月中下旬。造林密度对宽叶蓝靛果苗木生长有一定影响,适合的造林密度能促进苗木生长,以1 m×1.5 m的密度较为适宜。  相似文献   

气候变化情景下毛竹潜在分布及动态预测     

陈禹锦  罗喻才  于芬  杨光耀  张文根 《世界竹藤通讯》2021,19(3):5

为探究毛竹的潜在分布及其动态变化，并确定对其分布起主导作用的环境变量，文章基于MaxEnt预测模型，利用环境变量图层及316个毛竹分布点数据研究毛竹地理分布的变化。结果显示：1）限制毛竹分布的主要环境变量为最干月降水量、年均降水量、最冷月最低温、年平均温、温度年较差和海拔；2）当前毛竹的潜在适生区主要位于中国东南部，与亚热带季风气候区大致重叠，高适生区主要位于总适生区的东部和西北部；3）在未来气候情景下，毛竹总适生区面积有所缩减，各不同等级适生区面积变化大，其中高适生区面积大幅度缩减。研究获得的毛竹适生区变化趋势可为毛竹培育、引种以及入侵防治提供参考。  相似文献   

Genetic variation analysis of the genus Passiflora L. using RAPD markers     

Diego Fajardo  Fernando Angel  Mikkel Grum  Joe Tohme  Mario Lobo  William M. Roca  Inés Sanchez 《Euphytica》1998,101(3):341-347

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发根农杆菌感染导致紫果西番莲遗传转化     

林顺权 《福建农林大学学报(自然科学版)》1998,(2)

将发根农杆菌ＭＡＦＦ０３－０１７２４株系,涂布于逆向插入未添加任何生长调节剂的ＭＳ培养基中的紫果西番莲的茎段切口上．４周后,切口上出现瘤状突起,次周产生不定根．切下不定根根尖,培养于含Ｃｌａｆｏｒａｎ０．５ｇＬ－１的培养基中,分化出发状根．发状根转入含有ＢＡ１ｍｇＬ－１和２,４－Ｄ０．１ｍｇＬ－１的ＭＳ培养基中,分化出植株．再生植株经滤纸电泳检测,测出了农杆碱和甘露碱,说明紫果西番莲已发生了遗传转化．  相似文献   

A physiological and biochemical approach to selecting the ideal diet for Ostrea edulis (L.) broodstock conditioning (part A)     

Ricardo González‐Araya  Isabelle Quéau  Claudie Quéré  Jeanne Moal  René Robert 《Aquaculture Research》2011,42(5):710-726

To select the best microalgae for Ostrea edulis conditioning, four single species diets were fed to batches of broodstock, which were then compared using physiological and biochemical approaches. Ingestion and absorption were first studied, showing that Chaetoceros gracilis and Skeletonema marinoï were efficiently ingested (4.9–5.3 mg g^?1 h^?1) and absorbed (1.9–2.5 mg g^?1 h^?1) while Tetraselmis suecica led to the lowest physiological responses (0.36 and 0.12 mg g^?1 h^?1 respectively). When O. edulis were fed any microalgae except T‐ISO with only 79 mg g^?1, gonads accumulated carbohydrates from 116 to 141 mg g^?1 and the extent of accumulation depended on the species supplied in the order T. suecica<C. gracilis<S. marinoï. When oysters were fed either of the diatoms (C. gracilis or S. marinoï), an efficient transfer of 20:5(n‐3) to all tissues, including the gonads, was recorded while no enrichment in 22:6(n‐3) occurred in all tissues (polar fraction) when oysters were fed T‐ISO. In contrast (22:5(n‐6)), a characteristic fatty acid of T‐ISO accumulated in all tissues, confirming its allocation despite particularly low ingestion (1.66 mg g^?1 h^?1) and absorption (0.32 mg g^?1 h^?1). When oysters were fed C. gracilis or S. marinoï an efficient transfer of cholesterol and campesterol from diatoms to the gonads was observed, while no sterol accumulation occurred in the gonad when fed T. suecica. Because of low ingestion, absorption and poor biochemical compounds' transfer, T. suecica is not recommended for O. edulis conditioning. T‐ISO also exhibited low physiological performances but due to a specific 22:6(n‐3) enrichment in the gonad neutral fraction (16.1%), its potential role in reproduction should be considered. Chaetoceros gracilis is highly recommended for O. edulis broodstock while a source of DHA other than that provided by T‐ISO should be found due to its poor absorption. Because a mixed diet has been shown to be more efficient for O. edulis broodstock conditioning, complementary trials dealing with the effects of other species rich in 22:6(n‐3) such as Rhodomonas salina or Pavlova lutheri should be performed.  相似文献   

厚壁毛竹春季光合日变化及其与主要环境因子的关系初探          下载免费PDF全文

李迎春  杨清平  陈双林  吴明 《林业科学研究》2009,22(4)

光合作用是植物重要的生理过程之一,是植物物质生长的基础[1],对植物生长发育具有重要意义.光合作用的强弱取决于树木的遗传性和环境条件的影响,由于光合作用与树木生长地环境条件的密切关系,光合强度在引种驯化中常作为评价树木适应性的重要指标.树木对某一地区的适应性,是其对该地区各种环境条件的生理生态反应的综合表象.  相似文献