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STUDY ON THE TREE GROWTH, ARCHITECTURE AND STAND STRUCTURE OF KOREAN PINE PLANTATION
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作者 葛剑平 李传荣 +1 位作者 李平 李景文 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1995年第3期84-88,共5页
The artificial pure and mixed Korean pine (Pinus koraiensis) forests were investigated at Dailing Forestry Bureau in Xiaoxing'an mountains from 1990 to 1992. Depending on the distance between the samplings of Kore... The artificial pure and mixed Korean pine (Pinus koraiensis) forests were investigated at Dailing Forestry Bureau in Xiaoxing'an mountains from 1990 to 1992. Depending on the distance between the samplings of Korean pine and their neighbor trees, the neighbor tree height, the size of neighbor tree canopy, and dimension of neighbor tree. The forest structure was classified into three types: (1) prowth of a tree in the light (open), (2) Growth of a tree in the canopy gap (Gap), (3)Growth of a tree under broad-leaved tree canopy. The frequeney, height, and age of stem divergence of Korean pine tree were investigated by sampling trees. The temporal and spatial model of the tree growth was applied on basis of the height of stem divergence, ratio of height and DBH, and character of tree stem.The morphology and growth character of Korean pine trees during different development stage were forecasted. 展开更多
关键词 Korean pine plantation tree growth model Stand structure
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阔叶红松林林木与林分生长对采伐干扰的响应 被引量:1
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作者 岳庆敏 何怀江 +2 位作者 张春雨 赵秀海 郝珉辉 《生态学报》 CAS CSCD 北大核心 2024年第5期2019-2028,共10页
提升森林质量、修复生态功能是东北阔叶红松林生态修复的核心,而阐明林木与林分生长对采伐干扰的响应机理是其中的关键。森林对采伐干扰的响应会受到空间尺度、时间尺度以及干扰程度等因素的综合影响。以往的研究侧重于比较不同采伐处... 提升森林质量、修复生态功能是东北阔叶红松林生态修复的核心,而阐明林木与林分生长对采伐干扰的响应机理是其中的关键。森林对采伐干扰的响应会受到空间尺度、时间尺度以及干扰程度等因素的综合影响。以往的研究侧重于比较不同采伐处理下林木生长的相对大小,而忽视了不同恢复时间下,林木和林分生长随干扰程度的变化。以吉林蛟河阔叶红松林采伐样地为对象,基于连续四次样地调查数据(2011、2013、2015、2018年),分别探讨了林木和林分生长在不同恢复阶段对不同程度采伐干扰的响应,并通过构建分段模型确定采伐干扰阈值。结果显示:林木和林分生长对采伐干扰的响应并不一致,采伐促进了林木生长,并且林木生长量随采伐强度的升高而升高;采伐降低了林分生产力,林分生产力随采伐强度的升高而降低。林木和林分生长对采伐干扰的响应存在时滞效应:林木和林分生长在采伐后两年内并无显著变化,而在采伐三年后才发生明显变化。此外,分段模型的结果显示:当保留木断面积为21.6 m^(2)/hm^(2)时,林分生产力最高,表明通过密度调整使阔叶红松林胸高断面积维持在21.6 m^(2)/hm^(2)附近,可使林分处于较高的生产力水平、促进森林恢复。研究结果能够为制定科学的阔叶红松林生态修复策略提供技术支撑。 展开更多
关键词 阔叶红松林 采伐干扰 林木生长 林分生产力 采伐强度
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基于地基雷达数据构建红松人工林树高、枝下高及接触高模型 被引量:1
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作者 刘明睿 贾炜玮 《森林工程》 北大核心 2024年第1期26-36,共11页
采用地面激光雷达(Terrestrial Laser Scanning,TLS)扫描10块人工红松林所得到的数据,与实地调查数据相结合,构建红松树高曲线模型、枝下高预估模型与接触高预估模型,并建立联立方程组。首先,从所选择的5种树高曲线模型中,选择出拟合效... 采用地面激光雷达(Terrestrial Laser Scanning,TLS)扫描10块人工红松林所得到的数据,与实地调查数据相结合,构建红松树高曲线模型、枝下高预估模型与接触高预估模型,并建立联立方程组。首先,从所选择的5种树高曲线模型中,选择出拟合效果较好的2个模型作为联立方程组的备选模型。然后再从5个枝下高基础模型中选出1个拟合效果好,并且适用程度高的模型作为基础模型,运用再参数化和最优子集回归的方法将林分因子(林分平均胸径、林分断面积、高径比、优势木平均胸径和优势木平均高)代入基础模型,选择拟合效果较好的模型作为枝下高备选模型。相同的方法选择拟合效果好的接触高备选模型。最后将树高曲线模型、枝下高备选模型与接触高备选模型分别两两联立,建立联立方程组。通过似不相关回归(Seemingly Unrelated Regression Estimation,SVR或SURE),根据拟合优度与检验结果选择最优秀的方程组,并对联立方程组进行评价。最终得到结果最优联立方程组预估树高时,决定系数R^(2)=0.896,均方根误差RMSE=0.612 m;当方程组预估枝下高时,R^(2)=0.575,RMSE=0.850 m;当方程预估接触高时,R^(2)=0.719,RMSE=0.791 m,而且各种检验指标都较好。综合来看,方程组对树高、枝下高与接触高拟合精度与检验效果较好,可以解决树高、枝下高与接触高的内在相关性问题,为进一步研究红松树冠结构与动态变化提供基础。 展开更多
关键词 红松人工林 地基雷达 树高模型 枝下高模型 接触高模型
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树干注药技术的基本原理与应用
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作者 李东振 马健 +3 位作者 马帅 理永霞 杨灿 张星耀 《中国森林病虫》 北大核心 2024年第4期28-35,共8页
树干注药技术具有施用精准、药物利用率高、接触风险低和环境污染少等优点。当喷洒和灌根施药等手段难以发挥作用或对环境造成污染时,树干注药是更为合适的手段,其开发和应用已引起国内外广泛关注。概述树干注药技术的树木生理学原理和... 树干注药技术具有施用精准、药物利用率高、接触风险低和环境污染少等优点。当喷洒和灌根施药等手段难以发挥作用或对环境造成污染时,树干注药是更为合适的手段,其开发和应用已引起国内外广泛关注。概述树干注药技术的树木生理学原理和影响树干注药的因素,系统介绍国内外无压力注射、打孔压力注射和微孔压力注射的技术设备和特点,以及树干注药技术在防治松材线虫病等病虫害中的应用,旨在为树干注药技术的发展和优化提供参考。 展开更多
关键词 松材线虫病 树干注药 森林保护 树木健康
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基于“感知-偏好-人格”的传统园林花木人格化研究:以《全唐诗》松树为例
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作者 尹以俗 刘娟娟 《中国园林》 CSCD 北大核心 2024年第4期139-144,共6页
景观偏好是个体、群体或民族对特定景观的态度和偏好。历史悠久、意蕴深远的传统园林花木景观偏好和人格化现象,推动了中华民族健康和谐的社会人格构建,意义重大。花木五感景观偏好与人格关联是关键科学问题。引入人格神经科学,首先从... 景观偏好是个体、群体或民族对特定景观的态度和偏好。历史悠久、意蕴深远的传统园林花木景观偏好和人格化现象,推动了中华民族健康和谐的社会人格构建,意义重大。花木五感景观偏好与人格关联是关键科学问题。引入人格神经科学,首先从花木影响人格发展的“感知-偏好-人格”神经心理过程,构建研究框架;其次,以古代大数据《全唐诗》所见松树为例,基于NVivo软件和扎根理论方法,发现:(1)诗人偏爱松树,共有3044首描写松树五感景观的唐诗,占比高达6.22%;(2)其中,以视觉景观为主,听觉和触觉次之,占比分别为82.85%、10.09%和9.23%;(3)松树视觉“青”“霜雪”“孤”“鹤”“风云月”等和听觉“风中松声”共计1432个编码,体现了中华民族集体松景观偏好,与坚韧不屈、贞节不阿、超凡脱俗的“百木长”松格建立关联。“感知-偏好-人格”研究框架,能较为全面有效地揭示传统花木五感景观偏好与人格内在关联。 展开更多
关键词 风景园林 《全唐诗》 松树 扎根理论 景观偏好 花木人格化
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北京地区松柏树种修剪期与流松脂的关系
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作者 石东方 《林业勘查设计》 2024年第3期89-94,共6页
以油松、白皮松、华山松、侧柏、桧柏5个树种为材料,在一年中的不同时期,选择不同直径、留桩与否、枝梢修剪,探索修剪与流松脂的关系,确定适宜的修剪时期。结果表明,油松、白皮松、华山松3个树种适宜的修剪期为12月中旬至次年2月中旬,... 以油松、白皮松、华山松、侧柏、桧柏5个树种为材料,在一年中的不同时期,选择不同直径、留桩与否、枝梢修剪,探索修剪与流松脂的关系,确定适宜的修剪时期。结果表明,油松、白皮松、华山松3个树种适宜的修剪期为12月中旬至次年2月中旬,侧柏、桧柏适宜的修剪期为11月上中旬至次年3月中旬;枝条直径、留桩与否与流松脂无明显相关性;松树、柏树枝梢流松脂差异明显,剪去枝梢后油松、白皮松、华山松3树种剪口有松脂流出,侧柏、桧柏剪口没有松脂流出。 展开更多
关键词 北京 修剪期 松脂 松柏树种
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松材线虫病疫木处理中物理方法的应用——以柳州市莲花山保护区为例
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作者 张承就 《绿色科技》 2024年第13期130-133,137,共5页
阐述了疫区疫木清理的流程,介绍了松材线虫病疫木的处理方法,分析了各种方法的应用情况。指出了疫木清理前应进行疫情调查与评估,以此为基础规划疫木清理计划,并采取封锁疫区防止疫情扩散,伐除疫木等措施。疫木物理处理方法主要包括粉碎... 阐述了疫区疫木清理的流程,介绍了松材线虫病疫木的处理方法,分析了各种方法的应用情况。指出了疫木清理前应进行疫情调查与评估,以此为基础规划疫木清理计划,并采取封锁疫区防止疫情扩散,伐除疫木等措施。疫木物理处理方法主要包括粉碎(削片)处理、烧毁处理、旋切处理、钢丝网罩处理,需要结合实际情况选择合适的处理方法,以达到既有效杀灭线虫,又尽可能减少资源浪费和环境污染的目的。柳州市莲花山保护中心已累计处置超40000株松材线虫病疫木;微波处理和真空/蒸汽处理是未来柳州市莲花山保护区松材线虫病疫木处理的主要发展方向。研究强调了疫木处理的重要性,并提供了多种物理处理方法。未来应持续探索和改进疫木处理措施,形成更加科学、经济、环保的处理体系。 展开更多
关键词 松材线虫病 疫木处理 物理方法 应用
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不同药剂树干注射对松材线虫病的林间防治试验
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作者 潘琪 《绿色科技》 2024年第5期127-130,共4页
为探讨药剂树干注射对松树松材线虫的林间防治效果;于广西钦州某国有林场选择6块100株胸径约25 cm的松树进行了试验,共设置了6个小组,每组100株,分别为对照组、20%阿维菌素乳油组、0.3%苦豆碱水剂组、10%甲维·吡虫啉可溶液剂组、5... 为探讨药剂树干注射对松树松材线虫的林间防治效果;于广西钦州某国有林场选择6块100株胸径约25 cm的松树进行了试验,共设置了6个小组,每组100株,分别为对照组、20%阿维菌素乳油组、0.3%苦豆碱水剂组、10%甲维·吡虫啉可溶液剂组、5%高效氯氰菊酯乳油组、5%啶虫脒注干剂组;对照组注射等量药剂的清水,其余的药剂组均注射对应的化学药剂;于2020-2023年对试验松树的枯死情况进行调查,同时每年10月底统计墨天牛的诱捕数量。结果表明:以20%阿维菌素乳油组的防治效果最优,该组2020年、2021年、2022年和2023年的林间防治率分别为80.74%、78.48%、74.06%和70.57%,防治率均高于70%,随着年限的延长各个小组的林间防治率均逐渐下降,20%阿维菌素乳油组的防治率均显著的高于其他各个药剂组(P<0.05);防治效果其次的为10%甲维·吡虫啉可溶液剂组,10%甲维·吡虫啉可溶液剂组2020年、2021年、2022年和2023的防治率均高于5%高效氯氰菊酯乳油组;5种树干注射的药剂诱捕松墨天牛数量比较为:5%啶虫脒注干剂组>0.3%苦豆碱水剂组>10%甲维·吡虫啉可溶液剂组>5%高效氯氰菊酯乳油组>20%阿维菌素乳油组,其中20%阿维菌素乳油组、5%高效氯氰菊酯乳油组诱捕松墨天牛数量差异不显著(P>0.05);0.3%苦豆碱水剂组和5%啶虫脒注干剂组诱捕松墨天牛数量差异不显著(P>0.05),但是均显著高于20%阿维菌素乳油组、5%高效氯氰菊酯乳油组(P<0.05);以20%阿维菌素乳油树干注射效果最佳,其次为5%高效氯氰菊酯乳油。 展开更多
关键词 药剂 树干注射 松材线虫病 防治 效果
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午子山古树群松材线虫病综合防控效果初报
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作者 郭改改 《陕西林业科技》 2024年第3期79-82,共4页
松材线虫病是由松材线虫Bursaphelenchus xylophilus引起的一种系统侵染性病害,会对松属植物造成毁灭性病害,午子山以数万株挺拔苍翠的三级保护古树群(白皮松林)为景观特色,自白皮松林受松材线虫病侵染以来,古树群损伤极大,大有林毁景... 松材线虫病是由松材线虫Bursaphelenchus xylophilus引起的一种系统侵染性病害,会对松属植物造成毁灭性病害,午子山以数万株挺拔苍翠的三级保护古树群(白皮松林)为景观特色,自白皮松林受松材线虫病侵染以来,古树群损伤极大,大有林毁景逝之势,对午子山乃至整个秦巴林区及周围森林植被和生态安全造成严重威胁。本文综述了西乡县近年来按照午子山松材线虫病枯死木普查结果与《松材线虫病防治技术方案》(2022年版),采取就近就地焚烧、伐桩施药、覆膜处理等措施,严格执行疫木除治质量标准,确保除治成效的情况。此外,还对午子山白皮松林喷施药剂、悬挂诱捕器诱捕松墨天牛成虫,午子山健康白皮松打孔注药,有效降低死树数量及松材线虫媒介昆虫松墨天牛虫口密度,未来午子山乃至整个秦巴林区综合防治松材线虫病提出了展望。 展开更多
关键词 松材线虫病 松墨天牛 古树群 白皮松 综合防治
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RADIAL GROWTH OF HUASHAN PINE AND ITS RESPONSE TO CLIMATE 被引量:6
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作者 Shao Xuemei, Wu Xiangding(Institute of Geography, CAS, Beijing 100101 People’s Republic of China)Xi’an Laboratory of Loess and Quaternary Geology, CAS,xi’an 710061 People’s Republic of China) 《Journal of Geographical Sciences》 SCIE CSCD 1994年第Z2期88-102,共15页
Huashan pine (Finus armandii Franch) is a poential species for dendroclimatic study. Ring-width cores were sampled for four stands of two sites from the eastern extreme of the Qinling Mountains. The ring-width chronol... Huashan pine (Finus armandii Franch) is a poential species for dendroclimatic study. Ring-width cores were sampled for four stands of two sites from the eastern extreme of the Qinling Mountains. The ring-width chronologies developed in this study cover a maximum Period from A.D. 1359 t0 1992 and show high common chronology variance over the common period 1911-1960.All the chronologies are significantly correlated with all others, and the degree of correlation appears related to tree age. Response function analyses reveal that from 41 to 75 Percent of chronology variance can be accounted for by monthly mean air temperature and monthly total precipitation. A sufficiently strong correlation of ringwidth index with May and June rainfall and June temperature exists, implying soil moisture to be a limiting factor for Huashan pine growth. The association displayed by response diagrams between narrow rings, low precipitation, and high temperature during spring and early summer indicates a promising potential of ring widths for reconstruction of spring drought for the study area. 展开更多
关键词 tree-ring chronology DENDROCLIMATOLOGY Huashan pine climate-growth relationships
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Temporal changes in nitrogen acquisition of Japanese black pine(Pinus thunbergii) associated with black locust(Robinia pseudoacacia) 被引量:2
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作者 M.L.Lopez C. C.Mizota +2 位作者 Y.Nobori T.Sasaki T.Yamanaka 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第3期585-589,共5页
The alien woody legume, black locust (Robinia pseudoaca-cia), has invaded Japanese black pine (Pinus thunbergii) forests located in Japan’s coastal plain and hill regions where gaps are formed in pine forests aft... The alien woody legume, black locust (Robinia pseudoaca-cia), has invaded Japanese black pine (Pinus thunbergii) forests located in Japan’s coastal plain and hill regions where gaps are formed in pine forests after nematode infestation. Nitrogen fixation by legumes acceler-ates N cycling in forest ecosystems. We studied temporal change in the annual tree-ring resolution N stable isotope composition (δ15N, a per mil deviation of δ15N/14N ratio, relative to atmospheric N2δ15N=0‰) at two natural locations of Japanese black pine forest with black locust that differed in the time since black locust establishment (Shohnai in north-east and Kita-Kyushu in southwest Japan). Analyzed tree-rings covered the period from 1990/1992 to 2009. N acquisition by Japanese black pine from black locust N input to the soil was evidenced by temporal shifting of N stable isotope composition on the annual pine tree rings. With pro-gressive development of the forest stand,δ15N values of earlier tree-ringsδ15N of -5‰) from black pine associated with black locust shifted to-wards values similar to those of black locustδ15N values nearly to-1‰), which suggests acquisition of N by N2 fixation (Shohnai site). In con-trast, in a forest where black locust had settled for two or three genera-tions, in a black pine stand (Kita-Kyushu site), longer periods of N en-richment in the soil were reflected in the elevated tree-ringδ15N values of newly established black pine trees. Based on tree-ringδ15N data from the Shohnai site, we determined that about 10 years after black locust establishment, soil N had already been enriched by black locust N, this, in turn, contributed to N fertilization of surrounding trees in mixed stands. 展开更多
关键词 δ15N natural abundance Japanese black pine black locust nitrogen acquisition tree-RING
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Estimating Pinus palustris tree diameter and stem volume from tree height,crown area and stand-level parameters 被引量:15
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作者 C.A.Gonzalez-Benecke Salvador A.Gezan +3 位作者 Lisa J.Samuelson Wendell P.Cropper Daniel J.Leduc Timothy A.Martin 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第1期43-52,共10页
Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change. The objective of this study was to develop mode... Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change. The objective of this study was to develop models to predict longleaf pine tree diameter at breast height (dbh) and merchantable stem volume (V) using data obtained from field measurements. We used longleaf pine tree data from 3,376 planted trees on 127 permanent plots located in the U.S. Gulf Coastal Plain region to fit equations to predict dbh and V as functions of tree height (H) and crown area (CA). Prediction of dbh as a function of H improved when CA was added as an additional independent variable. Similarly, predic- tions of V based on H improved when CA was included. Incorporation of additional stand variables such as age, site index, dominant height, and stand density were also evaluated but resulted in only small improvements in model performance. For model testing we used data from planted and naturally-regenerated trees located inside and outside the geographic area used for model fitting. Our results suggest that the models are a robust alternative for dbh and V estimations when H and CA are known on planted stands with potential for naturally-regenerated stands, across a wide range of ages. We discuss the importance of these models for use with metrics derived from remote sensing data. 展开更多
关键词 Longleaf pine diameter-height relationships crown area individual-tree stem volume growth and yield modeling
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STUDY OF STRUCTURE AND DYNAMICS OF KOREAN PINE FOREST IN THE XIAOXING′AN MOUNTAINS
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作者 葛剑平 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1994年第4期1-5,共5页
The thesis for the Doctorate consist of two parts. The first is to study on structure, dynamics and tree growth of natural Korean pine forest. The second is to research for tree architecture, growth and stand structur... The thesis for the Doctorate consist of two parts. The first is to study on structure, dynamics and tree growth of natural Korean pine forest. The second is to research for tree architecture, growth and stand structure of artificial Korean pine (Pinus koraienstj) forcsts.The thesis comparcs the stand structure, process of regeneratio n, and various tree growth patterns between natural forests and artificial forests. Its purpose is to give a basis for forest management and silviculture. The study was carried out in Liangshui Experimental Forest Farm, which is located in the southern Xiaoxing’an Mountains. 展开更多
关键词 KOREAN pine FOREST tree GROWTH Structure Dynamics
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Life under Supernovae. Story of the Cordillera Pine Forest
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作者 Alexey Ju. Retejum 《Open Journal of Geology》 2019年第8期395-403,共9页
The article presents the first direct evidence of the influence of supernova flashes on the biosphere. Geochemistry and paleontology have not yet provided convincing data on the life response to disasters in the Milky... The article presents the first direct evidence of the influence of supernova flashes on the biosphere. Geochemistry and paleontology have not yet provided convincing data on the life response to disasters in the Milky Way Galaxy. This gap was eliminated through tree ring analysis of bristlecone pine from the Cordilleras responded to seven supernova outbursts in 185-1604 AD. The author used the superposed epoch method to process data at the 11 longest dendrochronologies, based on the results of measurement of annual growth of about 300 trees. The main finding is the growth depression in high-mountain population caused by supernova outbursts lasted for 20 - 30 years after the event. Moreover, in most cases, drastic growth reduction occurred one year prior to the event. In some cases, the annual tree ring increment exceeded the normal range many years after the event, and, consequently, it could be concluded that plant response was associated with the ozone layer depletion. 展开更多
关键词 SUPERNOVA Bristlecone pine trees CORDILLERA Plant Response OZONE Layer Depletion
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Effect of thinning intensity on tree growth and temporal variation of seed and cone production in a Pinus koraiensis plantation
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作者 Thanh Tuan Nguyen Dinh Tien Tai +2 位作者 Peng Zhang Muhammad Razaq Hai-Long Shen 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第3期835-845,共11页
Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth... Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands. 展开更多
关键词 Korean pine Thinning intensity SEED YIELD tree GROWTH Temporal VARIATION in CONE YIELD
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Ponderosa Pine Family Growth Comparisons in the Central Great Plains of Kansas
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作者 Wayne A. Geye Keith D. Lynch 《Open Journal of Forestry》 2011年第2期27-30,共4页
Ponderosa pine (Pinus ponderosa Laws.) has been planted widely in the Great Plains. Recommendations based on a 1968 study were to use material from south central South Dakota and north central Nebraska. A second test ... Ponderosa pine (Pinus ponderosa Laws.) has been planted widely in the Great Plains. Recommendations based on a 1968 study were to use material from south central South Dakota and north central Nebraska. A second test to further delineate seed sources (provenance/families) in this region was established in 1986. This paper reports results for survival, height, diameter, and D2H measurements in Kansas at 15 years. Results identify a wide range of suitable families within the Great Plains region.A majority of the tested sources performed well especially those from central Nebraska. Those sources from eastern Montana and western Nebraska performed poorly where environmental or geographic conditions were the poorest, thus verifying the original recommendations. 展开更多
关键词 PONDEROSA pine PINUS PONDEROSA PROVENANCE Seed Sources tree Selection GROWTH Characteristics.
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长白山6种阔叶树测定树木叶面积的最适叶片数量
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作者 刘颖 刘琪璟 +2 位作者 宋超杰 钱尼澎 秦立厚 《东北林业大学学报》 CAS CSCD 北大核心 2023年第12期66-73,共8页
2019年7—8月份,在长白山阔叶红松林中选取假色槭(Acer pseudo-sieboldianum)、色木槭(Acer mono)、蒙古栎(Quercus mongolica)、紫椴(Tilia amurensis)、糠椴(Tilia mandshurica)、拧筋槭(Acer triflorum)6个阔叶树种为研究对象,在采... 2019年7—8月份,在长白山阔叶红松林中选取假色槭(Acer pseudo-sieboldianum)、色木槭(Acer mono)、蒙古栎(Quercus mongolica)、紫椴(Tilia amurensis)、糠椴(Tilia mandshurica)、拧筋槭(Acer triflorum)6个阔叶树种为研究对象,在采集叶片前将树木大小划分为3个径级(小径树木(D_(1))、中径树木(D_(2))、大径树木(D_(3))),由于6种阔叶树的性状差异,树木大小3个等级对应的胸径(D)大小不一致(假色槭,D≤10 cm为D_(1)、10 cm<D≤15 cm为D_(2)、D>15 cm为D_(3);拧筋槭,D≤10 cm为D_(1)、10 cm<D≤20 cm为D_(2)、D>20 cm为D_(3);其余4个树种,D≤15 cm为D_(1)、15 cm<D≤30 cm为D_(2)、D>30 cm为D_(3)),每个等级选择3~4棵样树,每个树种选取10株;针对选取的样树、新鲜倒木,将树冠划分为上、中、下3部分,应用高枝剪等工具在树冠中部的东、西、南、北4个方位以及树冠底部、树冠上部2个方位,共6个方位,分别选取生长状况良好的叶片20片,每株树共计选取120片叶片,6个树种共采集叶片7165片(假色槭1193片、糠椴1162片、蒙古栎1139片、拧筋槭1216片、色木槭1311片、紫椴1144片),作为抽样总体。应用Excel进行数据基础分析,获取6个树种、3个胸径等级、6个取样方位的叶面积平均值和标准误差;应用R 4.2.3中的单因素方差分析法(ANOVA)对6个树种的叶面积进行方差分析,并通过多重比较法(Tukey HSD法)分析不同树种之间叶面积的差异性;应用t.test函数计算不同胸径等级、不同取样方位的差异性,分析不同树种在区分胸径等级和取样方位时叶面积均值与总体叶面积均值的差异;应用t检验法和随机抽样法,分析不同树种确定树木叶面积的最适叶片取样数量、6个树种在区分胸径和取样方位时确定树木叶面积的最适取样数量。结果表明:①不同树种的最适叶片取样数量不同,与种内的叶片变异系数密切相关。②6个树种的最适叶片取样数量分别为,假色槭644片、色木槭750片、蒙古栎677片、糠椴648片、紫椴697片、拧筋槭701片。③在径级和取样方位时对叶片取样,除了紫椴选择中等胸径树木的西方位取样,其余5个树种在野外工作环境时可选取中等胸径树木的下方位进行取样,最适叶片取样数量分别为,假色槭30片、色木槭46片、蒙古栎17片、糠椴65片、紫椴39片、拧筋槭66片。④综合试验研究结果,在野外采样时,应针对树种、胸径和取样方位,选择最适叶片取样数量,不应统一选择理论数据的25~40片叶片。 展开更多
关键词 阔叶红松林 阔叶树 叶面积 长白山
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融合超分辨率重建的YOLOv5松枯死木识别模型 被引量:4
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作者 王文瑾 游子绎 +5 位作者 邵历江 李小林 吴松青 张珠河 黄世国 张飞萍 《农业工程学报》 EI CAS CSCD 北大核心 2023年第5期137-145,共9页
为解决山地地形起伏大、无人机飞行高度高导致图像中尺度小且纹理模糊的松枯死木识别困难问题,该研究提出了一种在特征层级进行超分辨率重建的YOLOv5松枯死木识别算法。在YOLOv5网络中添加选择性核特征纹理迁移模块生成有细节纹理的高... 为解决山地地形起伏大、无人机飞行高度高导致图像中尺度小且纹理模糊的松枯死木识别困难问题,该研究提出了一种在特征层级进行超分辨率重建的YOLOv5松枯死木识别算法。在YOLOv5网络中添加选择性核特征纹理迁移模块生成有细节纹理的高清检测特征图,自适应改变感受野的机制分配权重,将更多注意力集中在纹理细节,提升了小目标和模糊目标的识别精度。同时,使用前景背景平衡损失函数抑制背景噪声干扰,增加正样本的梯度贡献,改善正负样本分布不平衡问题。试验结果表明,改进后算法在交并比(intersection over union,IoU)阈值取0.5时的平均精度均值(mean average precision,mAP50)为92.7%,mAP50~95(以步长0.05从0.5到0.95间取IoU阈值下的平均mAP)为62.1%,APsmall(小目标平均精度值)为53.2%,相比于原算法mAP50提高了3.2个百分点,mAP50~95提升了8.3个百分点,APsmall提升了15.8个百分点。不同算法对比分析表明,该方法优于Faster R-CNN、YOLOv4、YOLOX、MT-YOLOv6,QueryDet、DDYOLOv5等深度学习算法,mAP50分别提高了16.7、15.3、2.5、2.8、12.3和1.2个百分点。改进后松枯死木识别算法具有较高精度,有效缓解了小目标与纹理模糊目标识别困难问题,为后续疫木清零提供技术支持。 展开更多
关键词 无人机 图像识别 松枯死木 小目标检测 超分辨率重建 特征融合
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Simulation of the biomass dynamics of Masson pine forest under different management
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作者 ZHANG Gui-lian WANG Kai-yun +1 位作者 LIU Xin-wei PENG Shao-lin 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第4期305-311,共7页
TREE submodel affiliated with TREEDYN was used to simulate biomass dynamics of Masson pine (Pinus massoniana) forest under different managements (including thinning, clear cutting, combining thinning with clear cut... TREE submodel affiliated with TREEDYN was used to simulate biomass dynamics of Masson pine (Pinus massoniana) forest under different managements (including thinning, clear cutting, combining thinning with clear cutting). The purpose was to represent biomass dynamics involved in its development, which can provide scientific arguments for management of Masson pine forest. The results showed the scenario that 10% or 20% of biomass of the previous year was thinned every five years from 15 to 40 years made total biomass of pine forest increase slowly and it took more time to reach a mature community; If clear cutting and thinning were combined, the case C (clear cutting at 20 years of forest age, thinning 50% of remaining biomass at 30 years of forest age, and thinning 50% of remaining biomass again at 40 years of forest age) was the best scenario which can accelerate speed of development of Masson pine forest and gained better economic values. 展开更多
关键词 tree submodel BIOMASS Rate of nitrogen uptake Dinghushan Masson pine forest
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基于多色彩空间的YOLOv5松枯死树检测方法 被引量:3
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作者 游子绎 王文瑾 +4 位作者 邵历江 郭丹 吴松青 黄世国 张飞萍 《生物安全学报》 CSCD 北大核心 2023年第3期282-289,共8页
【目的】针对在松枯死树监测实践中,从无人机航拍RGB影像中自动识别松枯死树漏检率高的问题,提出了一种生产应用场景下基于多色彩空间的YOLOv5松枯死树高精度自动识别新方法。【方法】利用无人机采集大面积松材线虫病发生林分的RGB图像,... 【目的】针对在松枯死树监测实践中,从无人机航拍RGB影像中自动识别松枯死树漏检率高的问题,提出了一种生产应用场景下基于多色彩空间的YOLOv5松枯死树高精度自动识别新方法。【方法】利用无人机采集大面积松材线虫病发生林分的RGB图像,用Pix4Dmapper软件拼接,用LabelImg开源软件建立VOC格式的松枯死树数据集,分别用Faster R-CNN、YOLOv3、YOLOv4、YOLOv5、SSD和EfficientDet等6种基于深度学习的目标检测算法对数据集进行训练和测试,以精确率、召回率、平均准确率以及F 1分数作为评价指标筛选出最优目标检测算法;然后将采集的RGB图像转换成LAB和HSV色彩空间图像,再将这3个色彩空间的图像分别用最优目标检测算法进行训练,得到目标在每个色彩空间的边界框,使用非极大值抑制算法对这些边界框进行处理,得到最优边界框实现松枯死树自动识别。【结果】6种算法均取得良好效果,其中YOLOv5模型为最优算法,其精准率、平均查准率和F 1分数在6种算法中均最高,分别达到97.58%、82.40%和0.85。通过3个色彩空间融合后,反映漏检情况的召回率由74.54%提高到98.99%,平均准确率提升至98.39%。【结论】基于多色彩空间的YOLOv5模型能够显著提高从无人机航拍RGB影像中检测松枯死树的精度,为松枯死树监测提供了有力工具,也有助于松材线虫病的防治。 展开更多
关键词 无人机影像 松枯死树 深度学习 多色彩空间 松材线虫病
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