紫薇清防治薇甘菊林间药效试验

薇甘菊是一种危害林业生态系统物种多样性的恶性杂草。在林间使用不同浓度的紫薇清对薇甘菊进行防治试验,结果表明：喷药后90 d,高浓度紫薇清对薇甘菊防效达100%,低浓度者亦达到96.4%,对照药剂草甘膦防效为90.1%,三者差异显著。     

薇甘菊人工速效郁闭及其遮荫控制技术研究

薇甘菊发生区域的新造林地极易受到薇甘菊的侵袭、危害,为了寻找成本低廉、防效显著的薇甘菊控制技术,受森林郁闭度大于70%时薇甘菊难以生存且对周围其他植物不造成危害的自然现象启发,选择不同透光率的黑色塑料膜、三层遮阳网、二层遮阳网、一层遮阳网、黄色塑料膜、蓝色塑料膜,在薇甘菊发生较为严重的瑞丽市进行人工模拟郁闭、遮荫控制薇甘菊试验。结果表明,黑色塑料膜覆盖薇甘菊的透光率为0%,30d后能够迅速降低薇甘菊盖度至0%,降低薇甘菊生物量,致使薇甘菊花序数量为0个,影响其植株生长发育,导致薇甘菊迅速死亡;因此,黑色塑料膜是对薇甘菊速效郁闭、遮荫控制的最佳候选材料。     

薇甘菊颈盲蝽对薇甘菊的控制作用

在首次发现薇甘菊颈盲蝽专性取食薇甘菊的基础上,为阐明其对薇甘菊的控制作用,2011～2012年,通过田间试验研究薇甘菊颈盲蝽取食对薇甘菊生长、开花、结实的影响,室内选取健壮的颈盲蝽雌、雄成虫各10头研究薇甘菊颈盲蝽雌、雄成虫取食薇甘菊的方式、取食时间、取食部位、取食量、取食频率、控制能力。结果表明,薇甘菊颈盲蝽各虫态都嗜食薇甘菊嫩叶以维持生存,薇甘菊被颈盲蝽取食后,地面直立茎长度(59.83±0.60 cm),极显著小于未受害薇甘菊地面直立茎长度(79.53±0.48 cm);受害后花序数(92.4±15.29个),极显著小于未受害花序数(710.9±47.31个);AM 9∶00～PM 9∶00,雌成虫取食嫩叶面积(1.14±0.14 cm2),显著小于雄成虫取食嫩叶面积(3.47±0.50 cm2),均大于薇甘菊颈盲蝽选择取食最小新叶面积1 cm2,1头薇甘菊颈盲蝽成虫1天足以取食1对薇甘菊新叶片;雌成虫取食嫩叶的取食频率(1.12±0.12次/min),显著小于雄成虫取食嫩叶的取食频率(2.58±0.24次/min);每天下午薇甘菊颈盲蝽成虫取食较为活跃,雌成虫取食嫩叶虫口数量PM 7∶00达到峰值(6.0±1.26头),雄成虫取食嫩叶虫口数量PM 9∶00才可达到峰值(6.2±0.66头)。薇甘菊颈盲蝽具有取食能力强、食量大、取食频率高等特点,能对薇甘菊的茎生长产生影响,抑制其无性繁殖;也可对薇甘菊的花序分化产生影响,抑制其开花结实量,有效控制薇甘菊进行有性传播、扩散,是控制薇甘菊极为重要的一种天敌昆虫。     

薇甘菊的研究综述

通过调查有害杂草薇甘菊的生物学和生态学特性及其在广东省部分地区的分布和危害，综合已有的在薇甘菊的生态学防治，生物学防治和化学防治等方面的研究结果。对薇甘菊的各种防治策略作了进一步的论述，并对薇甘菊防治的研究方向作了初步探讨。同时，对如何大面积防治薇甘菊和彻底根除薇甘菊提出了综合建议。     

薇甘菊替代控制技术研究

薇甘菊可持续性管理是保护生态安全的必要措施,利用植物替代种植防控薇甘菊是一种新战略。为发掘可替代种植防控薇甘菊的植物及有效替代种植模式,对不同播种密度下7种草本植物和5种林木与薇甘菊混合种植的防治效果进行对比研究。研究结果表明,以3 000粒/m2的密度混合种植下薇甘菊的主茎长度、分枝数和生物量柱花草分别是0.88m、0.48枝和0.06g;东非狼尾草则分别是0.79m、0.93枝和0.07g;勃氏甜龙竹混合种植薇甘菊盖度为0.00%。上述数据与对照均存在显著差异,说明利用植物(如柱花草、东非狼尾草和勃氏甜龙竹)进行替代种植,可以有效防治薇甘菊。采取林木-草本混种的方式将是一种更为有效的薇甘菊替代种植技术模式。     

滇缅公路薇甘菊危害状况调查初报

为掌握云南薇甘菊危害核心区内薇甘菊发生危害的分布特征,2010年11月22日沿滇缅公路木康至畹町桥段路肩两侧200m进行薇甘菊发生危害情况调查。结果表明,滇缅公路薇甘菊分布不连续,呈板块、点状分布;纬度越低,距中缅边境越近,薇甘菊发生、分布点频度越高;薇甘菊发生点盖度变化大,厚薄不均,发生面积大小不等;危害植物高度由被侵害植物高度决定;覆盖能力强,危害植物种类多,表现极强的入侵、侵害性;薇甘菊分布点多在农业耕作区的田边、地角以及稀疏林地、河流、溪水、水沟边和农户院落四旁;林木郁闭度大的林地薇甘菊危害相对较轻,完全郁闭的林中尚未发生薇甘菊危害。     

薇甘菊在深圳内伶仃岛外地区的分布及其危害

薇甘菊是一种严重危害森林植被的有害杂草。作者在深圳内伶仃岛外地区设点调查薇甘菊的分布和危害状况，概述了薇甘菊的生物学特性、生态学特性。并建议立项对其进行防治研究。     

基于GIS的云南省薇甘菊潜在适生区研究

利用全球1 172个薇甘菊分布点、27个环境因子及Max Ent模型,预测并定量分析云南省薇甘菊不同等级适生区域及其面积。结果表明,云南省薇甘菊适生区主要分布于北纬25°以南地区,普洱市、德宏州、红河州有大范围高适生区;临沧市、西双版纳州和文山州有大范围的中等适生区;玉溪市、楚雄州、大理州有较大面积的低适生区。云南省薇甘菊适生区等级划分采用阈值较为合理,等级划分结果符合云南省实际情况。高适生区基本都是现有薇甘菊发生的地区,不同适生区等级气候生态条件与薇甘菊生长需求的层次也很吻合。本研究利用全世界1 172个薇甘菊发生点数据既包括了原产地中、南美洲,也包括了云南省被入侵地德宏州、保山市、普洱市等,提高了薇甘菊在云南省潜在分布区域预测的可靠性。     

薇甘菊的危害与防除研究

薇甘菊作为我国南方重要的入侵危害植物,近年来迅速蔓延。对农业、林业发展造成了极大危害。本文对薇甘菊的危害、防除的最新研究进展进行了综述。为进一步有效防除薇甘菊提供参考。     

基于Pleiades-1卫星数据薇甘菊信息提取

薇甘菊Mikania micrantha是一种极具危险性的外来物种,对侵入地生态系统的完整性构成了极大威胁,及时、准确掌握薇甘菊分布信息成为防控其入侵的关键技术。目前,薇甘菊的监测主要采用人工方法,耗时费力。随着遥感技术的发展,采用高分辨率遥感数据快速准确提取薇甘菊分布信息成为可能。以深圳市Pleiades-1影像为主要信息源,开展薇甘菊信息的快速提取研究。结果表明:(1)Pleiades-1影像分辨率较高,在开展薇甘菊识别时的最佳波段组合是R(B3)、G(B2+B4)/2、B(B1);(2)通过Brovey变换、Gram-Schmidt变换、Pansharpen变换的对比分析,Gram-Schmidt变换在信息量、最佳波段、清晰度等方面,均优于Brovey变换和Pansharpen变换,既保留了大量的原有信息,又增强目视解译效果,是影像融合时的最优变换;(3)基于光谱与纹理信息分析,提取薇甘菊信息范围更好;(4)薇甘菊信息提取的最佳分割尺度是30,综合识别精度达95.3%,说明采用高分辨率遥感影像能实现薇甘菊信息的精细识别。     

降香黄檀病虫害调查

2009年5月,在广东省肇庆市国有林业总场属下的3个林场和2个苗圃基地调查降香黄檀病虫害,结果表明,降香黄檀人工林幼树的嫩梢和叶片都存在轻度病虫为害,未见严重的危险性病害。主要害虫是螟蛾类蛀梢害虫,主要病害是炭疽病和细菌性穿孔病。     

广东省肇庆市降香黄檀早期造林效果初报

降香黄檀是我国南方大力推广的乡土珍贵树种之一。2009年12月在广东省肇庆市国有林业总场属下的怀集县大坑山林场、封开县大水口林场和肇庆市北岭山林场进行了降香黄檀造林效果的调查。结果表明：降香黄檀在肇庆市的生长表现良好,能适应当地的立地和气候条件,生长较快。不同的林场因立地差异在生长上有一定的差异,以大水口林场的降香黄檀林生长最快,胸径年平均生长量为0.97 cm,树高年平均生长量为1.15 m,冠幅年平均生长量为0.80 m;北岭山林场和大坑山林场的生长量小,但两地生长相差不大。调查结果还显示,抚育的同时适当修枝有利于幼林生长。     

10个降香黄檀家系在肇庆地区的早期生长评价

收集广东、海南、广西及福建地区 10 个降香黄檀（Dalbergia odorifera）种子并培育，比较分 析不同家系的早期生长表现。结果表明：不同家系间树高、地径、保存率存在极显著差异；综合生长指 标以肇庆广宁中学、广州华农林学院，海南乐东抱由林业局和海南乐东抱由苗圃场共4 个家系表现最好， 可作为降香黄檀采种育苗或无性繁殖的材料加以重点研究；树高与海拔存在显著正相关，说明一定范围 内较高海拔有利于树高的生长；年均降雨量与地径、保存率均存在显著正相关，说明一定范围内年均降 雨量越大，越有利于促进降香黄檀径的增长及提高苗木保存率。     

茶园套种降香黄檀效应的初步研究

根据降香黄檀和茶树的生物学、生态学特性及华安光照人林场的生态环境条件,采取林+茶栽培模式,开展了茶园不同密度套种降香黄檀试验。初步结果表明:降香黄檀造林平均成活率和保存率均达96%以上;2.5年生时,平均树高4.38m,平均地径5.16 cm,但不同坡向生长量差异极显著;降香黄檀抗冻能力强,表现出较好的适应性和速生性。套种密度为450~600株.hm-2比较适宜,不仅改善了茶园的生态环境,提高了茶叶产量和品质,而且使茶园的经济效益显著提高。     

Frost damage to planted Norway spruce seedlings — influence of site preparation and seedling type

Damage to Norway spruce (Picea abies (L.) Karst.) seedlings by summer frost was monitored on 10 clear-cuttings of various ages to which slash removal and four types of site preparation had been applied. The clear-cuttings were established on two sites (5 on each) in southern Sweden from 1989 through 1993 and planted each year from the year of cutting until 1993. In total, 7680 seedlings were analysed for frost injuries during the first three years following planting. The site preparation methods evaluated were: application of herbicide to ground vegetation; mowing of ground vegetation; scarification (mounding); and control. Two seedling types, bare-rooted and containerised seedlings, were evaluated.Periods of frost susceptibility were calculated using data on bud and shoot development during 1997 together with weather data for each of the studied years and sites. The date of flushing was well correlated to the air temperature sum (+5°C threshold value) in spring. Frost damage varied considerably between sites and study years. The lowest measured minimum air temperature and the frost-day sum during the frost-susceptible period were correlated to the frequency of frost damage. Soil scarification reduced frost damage in the first growing season. Bare-rooted seedlings had a considerably lower frequency of frost injury compared with containerised ones, possibly because flushing of the former was delayed. There was no statistically significant effect of herbicide application, mowing or slash removal on the frequency of frost damage. Seedling growth was significantly reduced by frost injury, especially in cases where injuries were sustained during several years. Survival was only slightly affected by frost damage.     

花梨木引种试验播种育苗技术研究

对花梨木进行播种育苗试验,研究播种时不同的种子处理方法、不同的播种时间对花梨木发芽、成活及苗木生长量的影响,结果表明,采用温水浸种和冬季播种可提高种子发芽率,冬播种子的平均发芽率达32%;花梨木冬播苗1年生平均苗高120 cm,平均地径0.5 cm,分别是春播苗的1.33倍和1.43倍。因此,花梨木进行播种育苗采用温水浸种和冬季播种,苗木的生长要好于春播苗。为今后花梨木的播种育苗提供参考。     

外源酚酸对降香黄檀幼苗生理的化感效应

为了研究巨尾桉根系分泌物中酚酸对降香黄檀生长的影响,以2年生降香黄檀幼苗为试验材料,参照二代巨尾桉-降香黄檀人工林土壤中6种酚酸含量(X),设置3个酚酸浓度(0.5X、1.0X和2.0X,以蒸馏水作为对照)处理,分析其对降香黄檀幼苗叶片叶绿素荧光特性、光合色素含量、抗氧化酶活性以及细胞膜透性等指标的影响。结果表明:不同质量浓度酚酸处理对降香黄檀幼苗叶片叶绿素荧光和光合色素含量的抑制作用较为明显。在2.0X浓度处理下,降香黄檀幼苗叶片最大荧光产量(Fm)、PSⅡ最大光化学效率(Fv/Fm)、类胡萝卜素含量、叶绿素a和总叶绿素含量的化感效应指数均小于0;在0.5X和1.0X浓度处理下,过氧化物酶(POD)活性受到抑制,提高了过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性,而在2.0X浓度处理时,3种酶的化感效应指数均小于0;随着酚酸浓度的增加,丙二醛(MDA)含量逐渐增加。通过综合敏感指数可知,6种酚酸对降香黄檀幼苗产生一定的抑制效应,但不同酚酸的作用方式及强度存在差异,苯甲酸的化感影响最大。     

Spring Frosts Affecting the Establishment of Second Rotation Crops in Thetford Chase

Spring frosts in Thetford Chase cause a major reduction in thegrowth of young Corsican pine and very severe frosts or repeatedfrosting may kill the trees. Records of temperatures taken ona range of sites and in different conditions have shown that(a) spring frosts occur every year at Thetford, but the severefrosts which kill trees outright may only occur once every fewyears, (b) frost damage to plants mainly occurs when the treesare less than 18 in (45 cm) tall, (c) forest clearings largerthan 5 acres (2 ha) do not act as artificial frost hollows,(d) cold air flows down slopes of more than 1° and accumulatesat the bottom, forming a frosty zone. Studies showed that frost damage can be minimized by (a) completecultivation, (b) deep ploughing, (c) underplanting, and (d)strip felling. The benefits of these measures are demonstratedby temperature records and by measurements of tree growth. Methods of reducing frost damage are necessary in areas proneto spring frosts if crops of Corsican pine are to be successfullyestablished at low cost.     

降香黄檀不同家系测定试验初报

通过对福建省华安县西陂国有林场降香黄檀不同家系的胸径、树高、平均冠幅以及冻害程度等指标的测定与分析,结果表明:降香黄檀不同家系间胸径和树高生长差异极显著,造林后1 a胸径为1.22~2.38 cm,树高为1.55~2.27 m;而冠幅生长差异不显著,平均冠幅为0.30~0.58 m。综合考虑胸径、树高和冻害3个因素初步判断,21、118、8、49、39、43、90、14、115、46、55、16、19等13个家系在福建华安表现较好。     

Frost hardening and dehardening in Abies procera and other conifers under differing temperature regimes and warm-spell treatments

Frequent bud frost damage in cultivation of Abies procera Rehderand pending climate changes are the background for this studyof cold hardiness under varying acclimation regime (in closed-topchambers) and experimental warm spells during the cold season.LT₅₀ values were established by freezing tests at differenttimes of year. Damage and deaths were assessed on leader buds,subapical lateral buds, needles and cambium. Minor parallelexperiments involved Abies nordmanniana, Picea abies and Piceasitchensis. Lower acclimation temperatures resulted in deeperfrost hardiness during late autumn but less during spring, comparedwith ambient temperature controls. Elevated temperatures resultedin less deep frost resistance. Apical buds generally developeddeeper frost hardiness than lateral buds but less deep thanthe cambium, varying with species, however. Frost damage inbuds ranged from death over partially destroyed bud contentsresulting in distorted shoots to buds seemingly remaining dormant.Responses to warm spells differed with duration, timing andspecies, ranging from dramatic decrease in frost hardiness withor without subsequent recovery to no reaction. Furthermore,the reactions did not show any clear relation to dormancy level.For A. procera, exposure to fluctuating temperatures appearedto be particularly problematic. This explains why this speciesdevelops best in coastal climates, and in sites sheltered fromtemperature extremes either by hedging, a winter snow cover,or topography. The Christmas tree production will suffer severelyon sites with harsh temperatures due to losses of lateral andterminal buds, which destroy the crown symmetry. Clipping ofgreenery is less influenced by frost damages, although the developmentof normal branch whorls is often disturbed.