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1.
IntroductionDendFOHffiussuPeransbrokeOutinShibazhanForestBureau,Daxing'anMount8insRegion,inJuneOf199o.TheinfeCtedareareachedo.8miIlionhm',takingup7o%offorestareaoftheBureau.AcCoFdingtotheinvestigation,DendFOhinussuPeransoccurredinnaturaIhaIfm8tureoryounggrowthforestmainIycomposedoflarch-TheaveragepopuIationdensityoflarvaereached283.5insectAree,andatthemoSt2256inseCts/treeinheaviIydestroyedstands-Den-dFOHmussuPeranshasonelif6circleovertWoyearsinthisarea.StandaFdplOtswereseIected… 相似文献
2.
This study explores the indirect relationship between forest structural measures and initial seedling survival and growth
along a structural gradient between 64% to 92% canopy closure. The gradient was created by applying various levels of midstory
removal to fifty 0.05 ha areas located within a mixed-hardwood riparian forest corridor. Twelve yellow-poplar (Liriodendron tulipifera L.) and cherrybark oak (Quercus pagoda Raf.) containerized seedling pairs were underplanted within each area. Canopy closure was estimated using hemispherical photography;
height-to-canopy and basal area were recorded at each seedling pair. Survival, basal diameter, and height were monitored through
two growing seasons. Species-specific mortality and height growth models were developed for one and two growing seasons following
underplanting. The interaction of height-to-canopy and basal area along with canopy closure were found to be the most strongly
related to mortality. Height to the forest canopy and initial seedling size explained the most variance in height increment.
Although the height increment models possess limited predictive power (R2 range from 0.22 to 0.36), both mortality and growth analyses emphasize the importance of quantifying vertical canopy structure,
along with the more commonly considered horizontal measures of forest structure (basal area and stem density), when evaluating
seedling development beneath a forest canopy. 相似文献
3.
[目的]通过对青海云杉1代无性系种子园自由授粉家系开展遗传评价,利用遗传测定结果提升青海云杉造林的良种化水平及提高良种使用率。[方法]本文以青海云杉初级种子园自由授粉家系测定林为研究材料,对13年生青海云杉家系树高、新梢长、保存率和11年生的主、侧梢冻害率进行了遗传评价,采用综合指数选择优良家系和最佳线性无偏预测方法预测单株育种值选择二代优树。[结果]研究结果表明:家系13年生的树高、新梢长、保存率和11年生主、侧梢冻害率的表型变异系数是24. 06%84%,遗传变异系数是3. 28%19. 31%。家系、家系和区组互作效应显著影响了13年生青海云杉树高和新梢长。树高和新梢长的家系遗传力分别是42. 5%和34. 2%,而单株遗传力是3. 00%,家系遗传力高于单株遗传力。采用综合指数选择法进行生长和抗性性状的综合选择,根据综合指数基于多样性和遗传增益进行平衡选择,有21个家系入选,入选家系的树高、保存率、主梢冻害率现实遗传增益分别为5. 66%、12. 59%和12. 96%。根据家系内单株13年生的树高育种值从1 103个单株中选择二代优树111个,单株入选率为10. 06%,入选二代优树树高的期望遗传增益是20. 10%。[结论]青海云杉13年生树高和新梢长在家系间存在显著变异,且还受家系与环境互作效应的影响,说明青海云杉家系的生长不仅受遗传的控制,还受遗传和环境的互作影响。根据各家系13年生树高和保存率和11年生主、侧梢冻害率综合指数值按35%的入选率综合选择21个家系,入选的家系不仅生长好,且抗性能力强,可用于回选优良无性系用于改扩建1代种子园或建立1. 5代种子园。 相似文献
4.
[目的]探究云南松林结构调整对林木生长和土壤性状的影响,为云南松林保护和利用提供科学依据。[方法]按照森林抚育规程对林分进行结构调整,采用典型取样法对比分析林分结构调整前后土壤性质和林木生长状况的差异。[结果]云南松林结构调整后,(1)结构调整样地单株蓄积量比对照样地提高了近60%,树高和胸径提高幅度均在15%以上,林下天然更新植株数量是对照样地的3.1倍;(2)结构调整后林内植物种类增加,林下灌木层和草本层盖度分别提高了63.3%和22.7%,灌木层和草本层平均高度分别提高了24.7%和17.9%;(3)结构调整样地现存凋落物量显著下降,与对照相比下降了20.4%,土壤表层温度、有机质含量、基础呼吸和土壤微生物生物量显著提高,土壤其他性质参数变幅相对较小。[结论]林分结构调整可显著提高云南松生长量,有利于云南松较大径级林木的培育;促进了云南松林下更新和林下植被发育,有利于林分群落结构的形成;提高了土壤微生物数量和活性,加速了土壤有机质转化,研究揭示林分结构调整促进了云南松林土壤—植物系统正反馈作用。 相似文献
5.
[目的]探索油茶林间作鼠茅草对土壤质量的影响,为油茶林地的科学经营提供参考。[方法]采用随机定点取样法,测定分析鼠茅草腐解过程中油茶林地0~20 cm耕作层土壤含水量、养分含量及酶活性指标的动态变化。[结果]鼠茅草间作对油茶林地0~20 cm耕作层土壤含水量、养分含量及酶活性影响显著。与对照相比,7—10月鼠茅草间作的土壤含水量平均增幅达39.62%;鼠茅草间作不仅显著提高了油茶林地0~20 cm耕作层土壤有机质、全氮、全磷及全钾含量,而且也提高了土壤中的水解性氮、有效磷与速效钾的含量,其中,有效磷增幅最显著,在8月下旬为对照组的9倍;鼠茅草间作对油茶林地土壤脲酶、酸性磷酸酶与过氧化氢酶的活性影响显著,对蔗糖酶活性影响不显著。[结论]鼠茅草间作经营一定程度上提高了油茶林地土壤肥力水平,对油茶林地土壤改良和可持续生产具有积极的作用。 相似文献
6.
Dendrolimus superans (Butler) occurred in the vast areas of Daxing’an Mountains forest, in Heilongjiang Province, in 1990. Stands damaged byI). Superans seriously, intermediately and lightly show patch shape distribution within damaged area. By ordination analysis and correlation
analysis between ordination factors and coordinate axis. It was found that occurrence ofD Superans in different extent is owing to the effect of forest age, composition and exposure. The tended young pure forests grown on
the sunward slopes are most seriously damaged and non-tended middle-age mixing stands grown on the sunless slopes are most
lightly damaged. Therefore, in order to preventD. superans from seriously damaging larch forests, relatively large crown density (P > 0. 7) should be kept, and broadleaf trees should
be also properly preserved.
This research project was supported by Scientific and Techndogical Committee of Heilongjiang Province 相似文献
7.
[目的]通过分析大兴安岭呼中林区兴安落叶松天然林胸径和树高的一元、二元分布特征,揭示脆弱地带森林群落的林木大小分布特征。[方法]在大兴安岭呼中林场设置3种不同类型兴安落叶松林固定样地,利用整体和分层的方法,对样地林分胸径和树高的变化规律以及两者之间的关系进行研究。[结果]表明:(1)草类-落叶松林直径分布为单峰分布,其他2块样地为双峰分布; 3块样地林木直径分布均呈左偏。杜鹃-落叶松林树高分布为多峰分布,其他2块地均为单峰分布; 3块样地林木树高分布均呈右偏。(2) 3块样地上、下层林木的直径分布均为单峰分布,上层木直径分布均呈左偏,下层木直径分布草类-落叶松林右偏,杜鹃-落叶松林左偏,杜香-落叶松林为近似正态。杜鹃-落叶松林的树高上、下层分布为双峰,其他2块样地均为单峰,3块样地上层木树高分布均左偏,而下层木树高分布均右偏。(3)草类-落叶松林和杜鹃-落叶松林小径阶林木株数占绝大多数。3块样地林分中树高与胸径的比值在小径阶林木中明显大于大径级林木。草类-落叶松林和杜鹃-落叶松林上层木中小径阶林木株数所占比例稍大,杜香-落叶松林和杜鹃-落叶松林下层木中大径阶林木株数比例稍大,但3块样地上层和下层木树高与胸径的比值在大小径阶林木中均无明显差异。[结论]高密度的杜鹃-落叶松林平均树高要高于低密度的杜香-落叶松林和草类-落叶松林平均树高,而平均胸径无明显差异。3块样地林分中树高与胸径的比值小径阶林木中明显大于大径级林木,但其差异在上层和下层林分中均表现不明显。 相似文献
8.
《Scandinavian Journal of Forest Research》2012,27(4):310-323
Abstract Adapting forest management practices to the changing environment of Komi Republic requires an understanding of the response of unmanaged natural forests to climatic changes. Komi Republic is a region of north-western Russia where large areas of natural boreal forest still exist. Apical growth of Scots pine (Pinus sylvestris L.) (108 trees, 529 discs) and Siberian spruce (Picea obovata Ledeb.) (88 trees, 423 discs) was analysed using stem analysis techniques. Mean apical growth curves were calculated for four zones of boreal forests in two subsequent 50 year periods starting from 1900. A statistically significant increase in height increment of 40% for Siberian spruce and 30% for Scots pine was identified from samples representing the Komi Republic. Within this region statistically significant height increment increases were found in the middle taiga zone for Siberian spruce of 240% and Scots pine of 140%, while northern taiga Siberian spruce increased by 164%. Taking into account that trees were samples in remote untouched pristine forests, the main causes of increased height increment are suggested to be climatic, which shows a large increase in temperature (0.43°C during the past 30 years) and a modest decrease in precipitation (2.2% over the past 30 years). 相似文献
9.
[目的]探寻适合油茶苗培育的最佳LED光质配比。[方法]以2年生长林4号油茶扦插苗为试材,LED白光为对照,研究LED红光、蓝光及其复合光对油茶苗生长和光合特性的影响。[结果]表明:L1(红光)处理下,油茶苗高生长量最大,但表观量子效率、光补偿点和胞间CO2浓度最小;L7(蓝光)处理下,油茶苗光补偿点最高,但高生长量、干物质含量、壮苗指数、气孔导度和蒸腾速率最小;L6(10%红光+90%蓝光)处理下,油茶苗地径生长量、干物质含量、壮苗指数、光合色素含量、表观量子效率、最大净光合速率、暗呼吸速率、气孔导度、蒸腾速率、实际光能转换效率和相对电子传递速率均最大;L4(50%红光+50%蓝光)处理下,油茶苗地径生长量、光合色素含量、最大净光合速率、实际光化学效率和相对电子传递速率均最小,且非光化学淬灭系数最大。[结论]与对照及其它处理相比,L6(10%红光+90%蓝光)处理更利于长林4号油茶苗生长和光合能力的提高,是培育油茶壮苗较为理想的光质。 相似文献
10.
Based on the investigation data about the species diversity in Daxing'an Mountains, the difference of species diversity indexes
betweenLarix gmelini forest andLarix gmelini-Betula platyphylla forest was analyzed by the Simpson index (D), Shannon-Wiener index (H), Pielou index (J
sw &J
si), Alatalo index (E
a) and Species richness index (S). The result showed that the species diversity index ofLarix gmelini-Betula platyphylla forest was much higher than that ofLarix gmelini forest in this region. AndLarix gmelini-Betula platyphylla forest was beneficial to maintain the species diversity in Daxing'an Mountains region.
Biography: SONG Guan-ling (1969-), female, Master, assistant professor in Zibo College, Zibo 255000, P.R. China.
Responsible editor: Zhu Hong 相似文献
11.
To support forest management decisions on converting stands from even-aged to uneven-aged management, tree models are needed
that can simulate both options. Therefore, an individual tree model for Pinus halepensis Mill. is compared with the respective yield table. The individual tree model is built from data of two Spanish forest inventories
in this province and evaluated with published yield tables, which have been built from permanent observational plots. The
individual tree model consists of a basal area increment model and a height increment model, both based on two measurements
of about 4,000 trees from single species stands of Aleppo pine. The R2 values of 0.362 and 0.107 for the basal area increment model and the height increment model, respectively, are within the
range of other published models of this type. Comparing the model with the yield tables for different site indices, we find
that our model matches the yield table well. Only in higher ages where the database for the yield table was poor, our model
indicates higher basal area growth rates than the yield table. 相似文献
12.
[目的]由于激光雷达技术已经能准确测定立木树高及相关树冠因子,应用该技术建立基于树高和树冠因子的立木材积模型,为激光技术在森林蓄积估计中提供技术支撑.[方法]利用云杉、冷杉、栎树、桦树4个树种组的3 010株实测样木数据,分析了立木材积与胸径、树高、树冠因子之间的相关关系;并通过对数回归方法构建了基于树高和树冠因子的立木材积模型,用确定系数R2和平均预估误差MPE等6项指标对模型进行评价.[结果]表明,立木材积与单一因子之间的相关,以胸径最为紧密,其次是树高,再次是冠长和冠幅.基于树高和树冠因子的立木材积模型中,以树高和冠幅作为解释变量的二元模型效果较好,再增加冠长因子的三元模型改进不大.云杉、冷杉、栎树、桦树4个树种组基于树高冠幅的立木材积模型,其R2分别为0.81、0.80、0.76和0.77,MPE分别为4.7%、5.3%、5.4%和5.3%,模型预估精度均能达到95%左右.[结论]本文对材积与林木因子之间相关关系的定量分析,建立了云杉、冷杉、栎树、桦树4个树种的立木材积模型,模型预估精度高.为激光雷达技术定量估测森林参数提供了依据. 相似文献
13.
[目的]分析侧柏生态公益林空间结构并进行经营迫切性评价,为侧柏生态公益林空间结构的优化调整及区域内其它生态公益人工林空间结构优化调整奠定理论基础。[方法]基于北京九龙山侧柏生态公益林的实测数据,选取混交度、大小比数、角尺度、密集度、林层指数、开敞度和竞争指数7个空间结构参数分析侧柏生态公益林的空间结构特征,并从密度、格局、竞争和混交等方面选取10个指标构建了经营迫切性评价指标体系并确定评价标准,进而对侧柏林进行了经营迫切性评价。[结果]侧柏生态公益林空间结构较为简单,林分呈均匀分布,树种组成单一,以零度和弱度混交为主,呈现单种聚集趋势;林木大小分化不明显,侧柏的优势度最大;林木之间较为密集,处于很密集和比较密集的林木比例较高;林分中所有林木几乎都分布在中林层与上林层,林层指数为0.288,林层结构不太明显;林分开敞度和竞争指数分别为0.274和0.318,总体处于生长空间不足、中度竞争状态;侧柏林的经营迫切性指数为0.8,经营迫切性等级为特别迫切,说明侧柏人工林大多数状态特征不符合标准,急需通过采取有效的经营措施优化林分配置,改善森林状况,以实现侧柏人工林可持续发展的目的。[结论]林分空间结构的分析与经营迫切性评价,不仅能够发现林分结构的不合理方面,还能针对性的制定空间结构调整措施,促进侧柏生态公益林不断向健康稳定的方向发展,实现其生态、经济和社会效益的持续发挥。 相似文献
14.
[目的]研究雷公山国家级自然保护区的棉革菌属外生菌根的分布情况,探索外生菌根与林木互利共生的关系。[方法]采用表型分析和r DNA ITS序列分析等方法,对贵州雷公山国家级自然保护区的常绿阔叶林、落叶阔叶林、暖性针叶林、灌丛4种优势林分的外生菌根进行研究。[结果]表明:基于形态及解剖结构特征分析,从4种优势林分中分离得到7种具有棉革菌属(Tomentella)典型特征(如颜色为棕色)的外生菌根; r DNA ITS区段系统发育分析表明,分离得到的7种外生菌根隶属棉革菌属,并可将其中6种形态型分别鉴定为T. badia、T. fuscocinerea、T.atramentaria、T. lapida、T. ramosissima和T. terrestris。[结论]首次从雷公山国家级自然保护区发现棉革菌属外生菌根真菌6种,为该属外生菌根与优势林分的共生关系及功能研究等提供参考。 相似文献
15.
[目的]通过对云南松天然林内云南松种内和种间竞争强度的测定,分析揭示竞争强度在云南松群落内的动态变化规律及云南松种群的生态适应机制.[方法]在云龙天池自然保护区云南松天然林设置样方进行群落学调查的基础上,采用Hegyi单木竞争指数模型,以云南松为对象木,定量分析林分、对象木、竞争木的竞争强度,采用回归分析方法建立对象木胸径与林分、种内、种间竞争强度的函数模型.[结果]天池自然保护区云南松天然林的种内和种间竞争强度分别为80.16%和19.84%;云南松种内与主要伴生树种种间竞争强度大小顺序为:云南松种内> 水红木> 华山松> 米饭花> 大白花杜鹃> 槲栎> 马缨花> 旱冬瓜;云南松与整个林分、伴生树种以及种内的竞争强度与对象木胸径之间存在显著负相关关系,对象木胸径越大,其竞争能力越强.[结论]云南松天然林内云南松的竞争压力主要来自种内竞争;林分种内及种间竞争强度与对象木胸径间存在CI=AD-B形式的幂函数关系;胸径20 cm以上云南松的竞争压力变化趋于平缓,胸径20 cm以下的云南松中、幼林是抚育管理的重点林分. 相似文献
16.
[目的]为了解红花尔基地区沙地樟子松天然纯林的结构特征,指导沙地樟子松的保护与经营。[方法]在红花尔基地区设置2块100 m×100 m的樟子松天然纯林固定样地,利用样地内每木定位调查数据和分析统计软件进行一元分布及二元分布特征分析。[结果](1)樟子松天然林纯林直径分布为单峰或多峰山状分布,垂直结构简单,只有乔木层和草本层。(2)樟子松天然纯林的林木分布格局为均匀分布,接近随机分布,林木分布格局类型与林分密度无关;林分中樟子松个体竞争激烈,多数单元中林木呈较密集状态。(3)2块样地中随机分布状态下的林木多数为中等密集或比较密集,不同分布状态下的林木优劣性差异较小;低密度樟子松天然纯林中多数密集状态的林木为绝对优势木或优势木,而高密度林分中林木密集度分布与林木大小无关。[结论]红花尔基沙地樟子松天然林结构不合理,应选择病腐木及聚集分布的个体作为潜在调整对象,进行密度调整和结构优化。 相似文献
17.
Li Pengfei Zhang Ximing Hui Enxian Liu Zhifang Ge Yuxiang Wang Jun Wang Daojun Wu Changyou 《林业研究》1998,9(4):264-268
The spatial distribution pattern of needle bright disease was mathematically studied. The results showed that it is tally
with negative binomial distribution. The infected area and damaged amount can be forecasted with this spatial distribution
pattern. Through the study on probability distribution of spatial points for single tree, the method and equations for calculation
of the disease index of whole forest belt were determined.
(Responsible Editor: Chai Ruihai) 相似文献
18.
《Scandinavian Journal of Forest Research》2012,27(2):163-167
In this study, the effect of shelterwood density on radial increment and stem form changes was evaluated after 9 yrs for a trial in a forest in northern Sweden dominated by Norway spruce [Picea abies (L.) Karst.]. Radial increment increased after the shelterwood cut, compared with control stands. The effect was of the same magnitude for sparse and dense shelterwoods. The response started in the third growing season and increased until the seventh season after release. The relative increment response was highest in the lower parts of the tree trunk, which indicates a reallocation of increment during the shelterwood period, causing a slight taper deterioration. 相似文献
19.
[目的]研究外来引进树种日本落叶松林凋落物对土壤养分的影响。[方法]采用分解袋法分别对18年生和24年生日本落叶松林以及周围针阔混交林凋落物的分解和养分释放规律进行了研究。[结果]凋落物分解和养分释放速率均表现为针阔混交林日本落叶松纯林;24年生日本落叶松林18年生日本落叶松林。其中不同林分的凋落物残留率与时间呈指数相关,凋落物年分解系数(K)也表现为针阔混交林(0.555 6)24年生日本落叶松林(0.445 0)18年生日本落叶松林(0.366 2)。凋落物分解速率与初始N元素含量呈极显著正相关,而与C/N比呈显著负相关,高的木质素含量对凋落物的分解有一定影响。C元素、K元素表现为直接释放模式,而研究中C/N比和C/P比相对较高,使N元素和P元素均表现为先富集后释放的模式。各养分元素的残留率总体呈现出18年生日本落叶松林24年生日本落叶松林针阔混交林的格局。[结论]不同林分凋落物分解和养分释放速率差异较大。凋落物年分解系数表现为针阔混交林24年生日本落叶松林18年生日本落叶松林。 相似文献
20.
[目的]筛选出强致病菌株用于木麻黄抗病育种研究工作。[方法]在广东沿海木麻黄青枯病发病区采集病根,开展病原菌两种不同分离方法的比较研究,对分离出的31个病株进行16s rRNA测序鉴定及致病性测定。[结果]采用稀释分离法及根系溢出法在TTC培养基上共分离出了31个病原菌株,根系溢出法操作简便,杂菌含量低,分离率在60%左右,可作为常规稀释分离法的补充。31个菌株进行分子鉴定,只有22个菌株扩增出了特异性条带,经测序比对确定这22个菌株为青枯菌。青枯菌株致病性测定结果显示菌株致病性在无性系间、菌株间及菌株与无性系间的交互作用均具有极显著差异(P0.01),不同接种方法间菌株致病性相关系数值较小,介于0.496 6~0.731 0之间,即室内水培接种与小苗盆栽接种不存在密切的直线相关关系。[结论]综合选择在不同无性系及不同接种方法中均具有较强致病性的GL-2、H、M、TC-1、F、Q菌株作为下一步木麻黄种质资源抗性鉴定及抗病育种研究试验菌株。 相似文献