艾虎气味对根田鼠行为和繁殖的影响(英文)

本文主要利用艾虎（Mustila eversmanni）气味作为捕食风险源，于1997年4月至12月在中国科学院西北高原生物研究所生态学实验室，研究其对根田鼠（Microtus oeconomus）社会行为、觅食、繁殖和性激素的影响。结果表明，当暴露于艾虎气味中时，根田鼠产生繁殖迟滞，且交配行为的频率显著降低(P<0.01)。与对照组相比较，雌体亲密行为和两性一般动作的累积时间显著增加（P<0.01）。两性一般动作（P<0.01）、探究活动（雌体：P<0.05；雄体：P <0.01）和自我修饰（P <0.01）的频次显著降低。同时，根田鼠能量的摄入（P<0.05）和体重（P<0.01）都显著降低。雌体的卵巢指数和胎仔重量也显著降低（P<0.01），雄体的附睾精子数则极显著降低（P<0.01）。艾虎气味条件下，根田鼠雌体的血清孕酮显著增加（P<0.01）。     

Deterrent effect of rosin and wood tar against barking by the gray-sided vole (Clethrionomys rufocanus bedfordiae)

The gray-sided vole (Clethrionomys rufocanus bedfordiae Thomas) is a small wild rodent widely distributed in Hokkaido, northern Japan. Floors of forestry plantations with thick herbage provide gray-sided voles with suitable habitats. The voles eat bark in winter, and because of this, severe damage can occur in many plantations. Deterrent effects on gray-sided voles of rosin and 3 wood tars were evaluated by two-choice tests in the field. These materials were selected because they were promising and economical deterrents. In the test for each material, disks were produced from trunks of Japanese larch, and used as carriers. Pairs of carriers (a material-treated carrier and a control carrier) were fed to gray-sided voles for 24 h, and values of the eaten area of bark were compared between treated carriers and controls. Every material decreased the extent of barking. The treated carriers were significantly less eaten compared to the controls for all the materials (p<0.01 or 0.05). Deterrent effects of three fractions (neutral, phenol, and strong acid fractions) made from wood tar were also evaluated. Every fraction prevented gray-sided voles from barking. The treated carriers were significantly less eaten compared to the controls for all the fractions (p<0.05). The neutral fraction has showed an especially strong deterrent effect; thus this fraction is most promising for future use.     

Efficacy of modified diatomaceous earth on different cockroach species (Orthoptera, Blattellidae) and silverfish (Thysanura, Lepismatidae)

Defined populations of American (Periplaneta americana), German (Blattella germanica), and Oriental (Blatta orientalis) cockroaches, and silverfish (Lepisma saccharina) were observed after exposure to deposits (25 g/m²) of a new 1,1,1–trimethyl-N-trimethylsilane-modified, highly hydrophobic diatomaceous earth (DE) formulation by using a computer-aided device measuring motility, circadian rhythm, and mortality under defined environmental and climatic field-simulating and exposure-enforced conditions. In a humid climate (85% relative humidity) with water and food offered ad libitum, complete population eradication could be achieved on the sixth day against B. germanica, on the eighth day against P. americana, and on the ninth day against L. saccharina, respectively. No population eradication occurred within 10 days of exposure when testing B. orientalis, showing a mean survival rate of 29.4 ± 6.7 % of the populations. When comparing the species-specific mortality rates with the results obtained from corresponding reference control groups, significantly higher mortality rates could be observed in B. germanica (F = 66; df = 52; P < 0.00001), P. americana (F = 344; df =66; P < 0.00001), L. saccharina (F = 253; df = 24; P < 0.00001), and B. orientalis (F = 422; df = 11; P < 0.00001). Overall, the efficacy of the hydrophobised DE examined ranked as follows: B. germanica > P. americana (F = 51; df = 24; P < 0.00001) > L. saccharina (F = 43; df = 24; P < 0.00001) >> B. orientalis (F = 9; df = 15; P < 0.000001). DE exposure resulted in complete disruption of the circadian activity in B. germanica and P. americana, but not when tested against B. orientalis, where the species-specific circadian motility peak was still preserved at lower levels after 10 days of exposure. In contrast to the cockroach species examined, no specific circadian rhythm could be measured in the L. saccharina control and treatment groups. Results indicate that hydrophobised DE originating from freshwater diatoms modified with 1,1,1-trimethyl-N-trimethylsilane can be successfully used for the control of infestations with German and American cockroaches as well as silverfish, but not against Oriental cockroaches. It is concluded that species-specific morphological, physiological and behavioural characteristics of insects influencing DE efficacy as well as the toxicological risk of modified DE to humans deserve further investigation.     

Nutrient element contents of cutting seedlings of hybrid species （ Liriodendron chinense x tulipifera）

The cutting seedlings ofLiriodendron chinense xtulipifera were treated with the different concentrations of auxin (treatment₁: IBA of 50 g·kg⁻¹+NAA of 300 g·kg⁻¹; treatment₂; IBA of 100 g·kg⁻¹+NAA of 300 g·kg⁻¹). The biomass nutrient element contents for different organs (root, stem, leaf) of cutting seedling ofLiriodendron chinense xtulipifera were measured by the dry method, Kjeldahl method and Atomic Absorption Spectroscopy method. The result showed that the biomass of root, stem, and leaf of the cutting seedling treated with auxin was all remarkably increased. The contents of element C in root, stem and leaf had no significant difference between the control and auxin treatments, while the contents of N, P, K and Ca in stem were much lower than that in leaf and root. Variance analysis showed that for the same organ with different concentration treatment of auxin, the four nutrient elements (N, P, K, and Ca) had no significant difference in contents, while there existed significant or very significant difference in contents of the four nutrient elements in different organs with the same concentration auxin treatment. The N, P, K and Ca contents were very low in cutting seedlings; as a result, additional fertilizer should be applied to the seedlings when they were planted in the field. Foundation item: This paper was supported by Jiangsu Province Science Foundation (BE96350). Biography: ZHANG Xiao-ping, (1972-), female, Ph. Doctor in Nanjing Forestry University. Nanjing 210037, P. R. China. Responsible editor: Zhu Hong     

Aphidicidal activity of some indigenous plant extracts against bean aphid <Emphasis Type="Italic">Aphis </Emphasis><Emphasis Type="Italic">craccivora</Emphasis> Koch (Homoptera: Aphididae)

Aphidicidal activity of hot and cold water extracts of some indigenous plants, Azadirachta indica A. Juss (neem), Calotropis procera (Aiton) W.T. Aiton (akanda), Polygonum hydropiper L. (biskatali) and Ipomoea sepiaria J. Koenig ex Roxb. (bankalmi), were tested against the bean aphid, Aphis craccivora Koch. Hot water extract of P. hydropiper and A. indica was found to be the most effective (87.6–94.5 and 80.47–89.6% mortality respectively, P < 0.01) among all the extracts. Other hot and cold water extracts also appeared to be useful (59.5–87.5% mortality) as pesticides for A. craccivora. The highest yield (3.25 kg per plant) was obtained using hot water extract of P. hydropiper followed by hot water extract of A. indica (3.15 kg per plant). The lowest yield (0.32 kg per plant) was recorded from the control block. All the phytoproduct treatments had significantly (P < 0.01) better yield than the control block.     

Electroantennogram responses of Dendrolimus superans (Lepidoptera: Lasiocampidae) to six volatiles of Larix gmelinii

Dendrolimus superans is one of the important pests feeding on the needles of Larix gmelinii. Six standard compounds, (1R)-(−)-α-pinene, (1S)-(−)-α-pinene, ocimene, (1S)-(−)-β-pinene, R(−)-α-phellandrene and camphene, the main volatiles of L. gmelinii were used to test the electroantennogram (EAG) responses of moths. The results show that the order of the EAG responses of moths to seven concentrations of these six compounds were as follows: mated females > virgin females > unmated males, except for 0.1 μL/μL R(−)-α-phellandrene, where the order was: virgin females > mated females > unmated males. There are statistically significant differences between the EAG responses of virgin females and unmated males (p < 0.05), and also between mated females with virgin females and mated females and unmated males (p < 0.01), which suggests that the mated females are more sensitive to the volatiles of host plant. The results of EAG responses of the mated females, virgin females and unmated males indicate that they are more sensitive to R(−)-α-phellandrene than to the other volatile components. The active time for the EAG responses of both mated females and unmated males occurs during the night, i.e., from 20:00 to 04:00 hours. This is consistent with their eclosion, mating and oviposition periods. __________ Translated from Scientia Silvae Sinicae, 2007, 43(7): 55–60 [译自:林业科学]     

Fire fighting truck-based emergency mosquito biolarviciding to prevent outbreaks of malaria and arboviral disease in Kabul, Afghanistan

Emergency control of disease vectors requires high efficacy, rapid reaction and safe use of biocides in order interrupt transmission cycles without harming humans, non-target animals and the environment. In countries with complex emergencies, air-borne large-scale vector control is often limited, or impossible, due to questionable security as well as military, safety, equipment, or logistical constraints. While facing a potential outbreak of malaria and dengue fever in the Kabul area, Afghanistan, combined with high abundance of anopheline and Culex mosquitoes, emergency mosquito larvae control with Bacillus thuringiensis var. israelensis (Bti) and methoprene were carried out. For the first time, larvicides were applied by using a modern fire fighting truck in combination with aerial imaging of potential breeding sites. Three treatments with 0.07 g a.i. sterilized, water-dispersible granular (WDG) Bti/m² in combination with 0.0014 g a.i. methoprene/m², or 0.07 g a.i. Bti/m² alone, were conducted on July 29, August 29, and September 28, 2004, and significantly reduced larval indexes of 96.5 (P < 0.0001), 96.7 (P < 0.0001), and 97.6% (P < 0.0001) against anopheline, and 98.2 (P < 0.0001), 95.6 (P < 0.0001), and 96.2% (P < 0.0001) against Culex larvae, respectively. Before the larviciding campaigns started, up to 222.4 ± 32.0 mosquitoes were captured per standardized light trap per night. During May until October 2004, the following anopheline and Culex species were abundant: A. superpictus (29.3%), A. fluviatilis (17.0%), C. pipiens (15.2%), and C. pseudovishnui (38.5%). After biolarviciding, abundance of adult mosquitoes, as measured by light trap catches 20 days post-treatment, decreased significantly in Anopheles at 81.4 (P < 0.0001), 87.1 (P < 0.0001), and 78.2% (P = 0.01), and in part significantly in Culex for 75.2 (P < 0.0001), 78.3 (P < 0.0001), and 30.8% (P = 0.463), respectively. After the treatment, mosquito-associated annoyance complaints and disease transmission decreased markedly, and not a single confirmed case of malaria or arbovirosis was reported. It is concluded that biolarviciding using a fire fighting truck as the application device is a highly successful, rapid, and cost-effective method to control vector mosquito larvae, and to reduce human exposure to mosquito-borne diseases during complex emergency situations.     

Molecular cloning and analysis of the partial sequence ofRhinopithecus roxellanae growth hormone gene

Growth hormone gene (GH) ofRhinopithecus roxellanae was amplified by PCR based on the sequences of the reported mammalian growth hormone gene for the first time. The amplified fragment was about 1.8 kb. It was cloned and its upper stream was sequenced. This sequencing region consists of a 5′flanking regulatory region, exon I and part of exon II, intron I of growth hormone gene. Comparing the corresponding sequences of growth hormone gene betweenRhinopithecus roxellanae and the porcine, we concluded that the homology reached 81% in the region, and there was high conservation in the 5′flanking sequence. The kinds of amino acids of exon I and exon II for about 90% were the same to those in pig. Many mutations occurred in the degenerate site of the triplet code. In the nucleotides of intron I, there were only 72% homologies with those in pig. It means that introns and 3′flanking sequence maybe play an important part in growth hormone gene regulation of the different animals. The project is supported by National Nature Science Foundation of china (No. 39970103). Xu Laixiang, male, born in March 1960, professor, Department of Biology, Qufu Normal University, Qufu 273165, P.R. China. Responsible editor: Zhu Hong     

Factors shaping genetic structure within populations ofEurya japonica (Theaceae)

Starch-gel electrophoresis was used to resolve nine polymorphic enzyme loci from leaf tissue collected from 20 Korean populations ofEurya japonica in order to determine differences in allele frequencies between male and female trees. In addition, 84 adults were sampled and mapped in a population located on Naenaro Island in Korea to examine spatial genetic structure using spatial autocorrelation analysis. Allele frequencies between males and females gave few contribution to the genetic structuring within populations. Only nine (5%) of 180 cases were significantly different from both sexes in allele frequencies. On the other hand, Moran'sI was significantly different from the expected value in 31 (23.5%) of 132 cases. In the shortest distance (0<5m),I was significantly positive in 10 (22.7%) of 44 cases. The results indicate that a significant small scale genetic structure was detected in the population and patch widths were inferred to be approximately 5–7 m. A nonrandom distribution of genotypes may be indicative of restricted gene flowvia seed and pollen dispersal, and patchy establishments of genetically distinct individuals. These factors are responsible for shaping population genetic structure ofE. japonica.     

Essential oil from the leaves of Cryptomeria japonica acts as a silverfish (Lepisma saccharina) repellent and insecticide

This is the first article to report the evaluation of a natural product used as an antisilverfish agent. Silverfish (Lepisma saccharina), primitive wingless insects, feed on a variety of materials, including paper, cotton, starch, and cereals. They can be a problem in libraries and other places where books, documents, and papers are stored. In this pilot study, the essential oil from leaves of Cryptomeria japonica was investigated to test its properties as a silverfish repellent and insecticide. The results from a repellency bioassay show that the essential oil significantly repelled silverfish. The repellent activity was 80% at a dosage of 0.01 mg/cm³. When silverfish were exposed to a concentration of 0.16 mg/cm³ of essential oil, they were killed within 10h. The chemical composition of essential oil, the emissions from a test chamber, and the residue left on filter papers previously soaked with the essential oil in a chamber were analyzed by gas chromatography-mass spectrometry. The components of the essential oil were found to be: elemol (18.22%), 16-kaurene (11.63%), 3-carene (9.66%), sabinene (9.37%), 4-terpineol (9.06%), β-eudesmol (5.70%), α-pinene (5.62%), and limonene (5.26%). Only some constituents of the essential oil compounds collected by solid-phase microextraction were found to be emitted in the test chamber. The main constituents were: 3-carene (21.03%), p-cymene (10.95%), limonene (9.49%), β-myrcene (9.39%), γ-terpinene (9.10%), α-terpinene (8.57%), and 4-terpineol (7.97%).     

尾叶桉×细叶桉木材密度与生长的联合选择

[目的]评估Resistograph钻刺法间接测定尾叶桉×细叶桉木材密度的可靠性,检测杂交亲本对子代表型的效应以及生长与木材密度的相关,评选速生、优质的尾细桉杂种。[方法]基于10株尾叶桉与10株细叶桉不完全析因交配产生的56个杂交组合的7.5年生试验林,利用79株分析容积法与Resistograph钻刺法测定的木材密度的相关,通过方差分析检测亲本对杂种生长和木材密度的效应,结合多重比较和独立淘汰法进行材积和木材密度的联合选择。[结果]容积法与Resistograph钻刺法测定的木材密度的表型相关系数为0.52(P0.001),遗传相关系数为0.55(P0.05);树高、胸径及材积的母本间和父本间均呈极显著差异(P0.001或0.01),但母本×父本互作的效应不显著;对钻刺木材密度,父本间呈极显著差异(P0.001),母本×父本互作显著(P0.05),但母本间差异不显著;树高、胸径和材积间的表型相关和遗传相关均极显著(P0.001),其与钻刺木材密度的表型相关极显著(P0.001),但遗传相关不显著;评选出速生、木材密度较高的杂交组合14个、单株17株。[结论]Resistograph钻刺法是一种间接测定尾细桉木材密度的简便、经济和可靠的方法;母本和父本选择以及母本与父本的组配对培育速生、材质优良的尾细桉杂种均较重要;尾细桉生长与木材密度的遗传相关不显著,需要对这两类性状分别进行选择;评选的尾细桉杂交组合和单株为培育速生、优质的桉树良种提供了有用的材料。     

The contribution of root respiration of<Emphasis Type="Italic">Pinus koraiensis</Emphasis> seedlings to total soil respiration under elevated CO<Subscript>2</Subscript> concentrations

The impacts of elevated atmospheric CO₂ concentrations (500 μmol·mol⁻¹ and 700 μmol·mol⁻¹) on total soil respiration and the contribution of root respiration ofPinus koraiensis seedlings were investigated from May to October in 2003 at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, Jilin Province, China. After four growing seasons in top-open chambers exposed to elevated CO₂, the total soil respiration and roots respiration ofPinus koraiensis seedlings were measured by a Li-6400-09 soil CO₂ flux chamber. Three PVC cylinders in each chamber were inserted about 30 cm into the soil instantaneously to terminate the supply of current photosynthates from the tree canopy to roots for separating the root respiration from total soil respiration. Soil respirations both inside and outside of the cylinders were measured on June 16, August 20 and October 8, respectively. The results indicated that: there was a marked diurnal change in air temperature and soil temperature at depth of 5 cm on June 16, the maximum of soil temperature at depth of 5 cm lagged behind that of air temperature, no differences in temperature between treatments were found (P>0.05). The total soil respiration and soil respiration with roots severed showed strong diurnal and seasonal patterns. There was marked difference in total soil respiration and soil respiration with roots severed between treatments (P<0.01); Mean total soil respiration and contribution of root under different treatments were 3.26, 4.78 and 1.47 μmol·m⁻²·s⁻¹, 11.5%, 43.1% and 27.9% on June 16, August 20 and October 8, respectively. Foundation item: This study was supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX1-SW-01) and the National Natural Science Foundation of China (30070158). Biography: LIU Ying (1976-), female, Ph. D. Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan     

Fertiliser and irrigation effects on wood density at various heights for <Emphasis Type="Italic">Pinus radiata</Emphasis>

This study examined the combined effect of 19-years of nitrogen fertilisation and irrigation on the basic density along the stems of Pinus radiata (D.Don). The sample trees came from two treatments in the Biology of Forest Growth experiment: the control (C no treatment) and the irrigated and liquid fertilised (IL irrigated from age 10 to 29, liquid fertilised from ages 10 to 17). The mean basic density at breast height in the IL trees was significantly less (P < 0.05) than the C trees (430 and 471 kg m⁻³, respectively). However, the mean density of the entire bole was not significantly different. Basic density decreased with height, with the density near the tips of the trees being only 80% of the density at breast height for both treatments. The relative rate of the decrease was different between treatments. The density of the C trees decreased steadily with height while the IL trees held a relatively constant density for about half their total height. The results show the importance sampling at several different heights when considering the effects of various treatments on wood basic density in Pinus radiata.     

Impact factors on fine root seasonal dynamics in Fraxinus mandshurica plantations

Fine root turnover plays important roles in carbon allocation and nutrient cycling in forest ecosystems. Seasonal dynamics of fine roots is critical for understanding the processes of fine root turnover. From May to October 2002, soil core method was used for estimating the seasonal pattern of fine root (diameter < 1 mm) parameters (biomass, specific root length (SRL) and root length density (RLD)) in a Manchurian ash (Fraxinus mandshurica) plantation located at the Maoershan Experiment Station, Heilongjiang Province, northeast of China. The relationships of fine root biomass, SRL and RLD with available nitrogen in soil, average soil temperature per month in 10 cm depth and soil moisture content were analyzed. Seasonal variation of fine root biomass was significant (P < 0.05). The peak values of fine root biomass were observed both in spring and in autumn, but SRL and RLD were the highest in spring and lowest in autumn. Specific root length and root length density were higher in spring and summer, which means that fine root diameter was thinner. In autumn, both parameters decreased significantly due to secondary incrassation of fine root diameter or the increase of tissue density. Seasonal dynamics of fine roots was associated with available nitrogen in soil, soil temperature in 10 cm depth and moisture content. Fine root biomass has a significant relationship with available NH₄ ⁺-N in soil. Available NO₃ ⁻-N in soil, soil temperature in 10-cm depth and moisture content have a positive correlation with fine root biomass, SRL and RLD, although these correlations are not significant (P > 0.05). But the compound effects of soil available N, soil temperature and soil moisture content are significant to every root parameter. The variations of these three root parameters in different seasons show different physiological and ecological functions in different growing periods. Translated from Scientia Silvae Sinicae, 2006, 42(9): 7–12 [译自: 林业科学]     

The penetration rate of laser pulses transmitted from a small-footprint airborne LiDAR: a case study in closed canopy, middle-aged pure sugi (Cryptomeria japonica D. Don) and hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.) stands in Japan

Penetration rates of laser pulses transmitted from a small-footprint airborne light detection and ranging (LiDAR) system in closed-canopy, middle-aged (40–50 years old) hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.) and sugi (Cryptomeria japonica D. Don) plantations that had similar levels of canopy openness were studied. The number of transmitted pulses was 107 427 points/ha for the hinoki cypress stand and 122 883 points/ha for the sugi stand. The penetration rates of the first (P_f) and second pulses (P_s) that reached the ground were 0.1% and 1.0% in the hinoki cypress stand, and 2.6% and 5.5% in the sugi stand, respectively. Penetration rates for the total number of pulses (P_f+s) that reached the ground within each stand were 1.1% and 8.1%, respectively, and values for P_f+s, P_f, and P_s for sugi and hinoki cypress stands were significantly different (P < 0.001). The results of this study indicated that the generation of accurate digital terrain models in dense hinoki cypress stands with complex topographies using only the data from laser pulses with poor laser penetration rates is likely to be difficult.     

干旱胁迫及复水对绿竹容器苗生理特征的影响

[目的]探究模拟干旱环境下水分亏缺对绿竹容器苗主要营养器官生理特性的影响,为绿竹规模化育苗栽培制定适宜的经营管理及节水灌溉技术方案提供理论依据。[方法]以绿竹组培苗为试验材料,采用盆栽苗控水方式,测定分析不同干旱胁迫条件下绿竹叶片及根系抗氧化酶、膜脂渗透性、叶片光合色素含量、以及根系活力等生理指标。[结果]表明:随着干旱胁迫加重,绿竹叶片叶绿素a、叶绿素b和类胡萝卜素含量明显下降,各处理间均达到差异显著(P0.05),复水后叶绿素a、叶绿素b、及类胡萝卜素含量均明显升高,其中叶绿素a、叶绿素b达到差异显著(P0.05),但类胡萝卜素差异不显著(P0.05);干旱胁迫下,根系活力呈明显下降趋势,中度干旱胁迫(MS)和重度干旱胁迫(SS)根系活力分别比对照(CK)下降14.35%、33.31%,均达到差异显著(P0.05),复水后,根系活力均明显升高,分别达到了CK处理根系活力的96.75%、73.84%;干旱胁迫下,根系及叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性和丙二醛(MDA)含量均呈上升趋势,且在复水后均呈现一定下降趋势,表现为中度干旱胁迫后复水(MS-CK)降低程度高于重度干旱胁迫后复水(SS-CK),各处理间均达到差异显著(P0.05)。[结论]模拟干旱环境下,增加干旱胁迫程度,绿竹的根系活力及叶片色素含量呈显著降低,MDA含量及SOD、CAT、POD活性均升高。复水后,根系活力及叶片色素含量较干旱胁迫时有所提高,MDA含量及SOD、CAT、POD活性有明显下降,不同干旱程度补偿能力不同,表现为中度干旱胁迫后复水高于重度干旱胁迫后复水,且不同营养器官对于解除干旱后消除活性氧及修复适应能力也不尽相同。绿竹根系活力和叶绿素含量与干旱胁迫程度呈负相关,而保护酶SOD、CAT、POD活性以及MDA含量均与干旱胁迫程度呈正相关。     

Fumigant and repellent activities of essential oil from <Emphasis Type="Italic">Coriandrum sativum</Emphasis> (L.) (Apiaceae) against red flour beetle <Emphasis Type="Italic">Tribolium castaneum</Emphasis> (Herbst) (Coleoptera: Tenebrionidae)

The biological activity of essential oil extracted from coriander, Coriandrum sativum L. (Apiaceae) against eggs, larvae and adults of Tribolium castaneum (Herbst) was investigated in a series of laboratory experiments. Bioassays conducted in air-tight glass chambers showed vapour toxicity and strong repellency on filter paper arena test towards all the stages used. Responses varied significantly (P < 0.001) within insect stages, dosages and exposures. At 12.0 μg/ml dosage, mortality of adults reached 95%, but for 12-, 14- and 16-days larvae, mortalities were 65, 74 and 82%, respectively. On the developmental inhibition, individuals fumigated at the larval stage confirmed that the percentage of larvae reaching to pupal stage and pupae to adult stage, decreased significantly (P < 0.001) with increasing dosage concentration. The oil fumigation yielded 100% mortality for T. castaneum larvae, pupae and adults at 0.08 μg/ml dosage. The oil had fumigant activity against eggs and the toxicity progressively increased with increased exposure times and concentrations. One hundred per cent T. castaneum egg mortalities were obtained with oil fumigation at 20 μg/ml and 96 h exposure period. C. sativum oil also showed highly repellent activity to the adults of T. castaneum, with overall repellency was 90% and at a dosage of 12 μg/ml repellency was 100% in a filter-paper arena test.     

Herbizideinsatz und Mäuse in Forstkulturen

Application of herbizides and voles in forest plantations Two areas in different spruce plantations were treated with Gramoxone® (Paraquat). Changes of the density of small mammals especially of the Field Vole(Microtus agrestis) and the Common Vole(Microtus arvalis) were observed. Residues of Paraquat in the excretions of marked individuals in the treated area were not detected with few exception. The problem of debarking young trees by starving voles and food scarcity caused by the weedkiller is discussed.     

板栗接种食用菌根真菌的菌根化效果及对幼苗促生效应的研究

[目的]通过板栗幼苗人工接种食用菌根菌固体菌剂,分析其对板栗幼苗生长指标和根系菌根化的效果,以验证大红菇(菌株编号2014-10)、红绒盖牛肝菌(菌株编号2014-14)和美味牛肝菌(菌株编号50559)这3种食用菌根菌固体菌剂作为板栗接种体的有效性及其促生效应,为进一步探索"板栗食用菌根菌新型经济林栽培模式"提供基础。[方法]在板栗播种时分别接种上述3种食用菌根菌固体菌剂,并设空白作对照。对当年生幼苗苗高、地径、根系干质量、侧根数、侧根总长、幼苗侵染率、吸收根侵染率等指标进行调查和分析,并制作菌根石蜡切片进行微观结构观察。[结果]表明:(1)上述3种食用菌根菌在人工接种下均能侵染板栗幼苗根系,平均幼苗菌根化率分别达95.8%、87.0%和96.7%,平均吸收根菌根化率分别达57%、53%和50%,达较高的侵染强度;经微观观察,板栗幼苗根系均形成典型的菌根结构——菌丝套和哈蒂氏网。(2)与对照幼苗相比,3个菌种处理幼苗的平均苗高分别提高32.5%、24.0%和22.7%,平均地径分别提高19.4%、14.1%和5.0%,差异显著(P0.05);平均根系干质量分别提高18.9%、25.3%和14.1%,平均侧根数分别提高16.0%、14.1%和12.1%,平均侧根总长分别提高26.8%、28.9%和44.8%,差异极显著(P0.01)。[结论](1)上述供试食用菌根菌均与板栗根系建立了共生关系,幼苗菌根化效果良好,吸收根菌根化强度高,形成了菌根的典型结构,即菌丝套和哈蒂氏网,验证了上述菌种固体菌剂的有效性,认为其可以作为板栗食用菌根菌栽培的接种体而用于生产实践,为探索"板栗食用菌根菌新型经济林栽培模式"提供了基础。(2)上述供试菌种接种后,对板栗幼苗各项主要生长指标均有不同程度的促进作用,说明上述食用菌根菌对板栗幼苗具有显著的促生效应。     

毛竹和林下植被芒箕凋落物分解特征研究

[目的]探讨竹林与其林下植被凋落物叶之间相互影响的潜在机制,为合理经营管理毛竹林林下植被提供理论参考。[方法]采用原位分解袋法研究了四川长宁毛竹与林下植被芒箕凋落物叶分解和养分释放过程。[结果](1)芒箕凋落物叶初始C、N、P含量和羟基碳高于毛竹(P 0. 05),而C∶N、C∶P、烷基碳、氧烷基碳和芳香碳低于毛竹(P 0. 05)。(2)凋落物叶分解和养分释放速率芒箕整体高于毛竹,芒箕和毛竹分解常数(k)分别为0. 58±0. 03和0. 73±0. 02,C、N、P养分释放均表现为净释放。(3)凋落物叶混合对分解速率没有显著影响,但抑制了N、P元素整个分解周期和C元素中后期的释放。(4)凋落物叶分解过程中元素含量变化格局表现为C含量和C∶N比整体呈下降趋势,N含量和N∶P比有小幅上升,P含量有微弱的下降趋势,C∶P比呈波动性变化。(5)凋落物叶分解速率与土壤温度、初始凋落物叶N和P含量呈显著正相关(P 0. 01),与初始凋落物叶的C∶N和C∶P呈极显著负相关(P 0. 01),与土壤含水量相关不显著。[结论]单独分解过程中,毛竹凋落物叶分解速率低于林下植被芒箕,养分释放特征均表现为直接释放;混合分解过程中,毛竹和芒箕凋落物叶分解速率无显著混和效应,但养分释放的混合效应表现出一定负效应和不同阶段性。