Establishing evaluation index system for desertification of Keerqin sandy land with remote sensing data

科尔沁位于我国东北部,地处东北平原向内蒙古高原的过渡地带(42°41'-45°15'N,118°35'-123°30'E),是受荒漠化影响较重的地区。利用外业调查数据,依据地表形态和生态状况的变化,确定了植被盖度、裸沙地占地百分比和土壤质地3 项评价指标,并建立了基于遥感的科尔沁沙质荒漠化评价指标体系,其中裸沙地占地百分比用混合像元分解的方法获得。利用外业调查的数据对该指标体系进行验证,结果表明该指标体系适于研究区域的荒漠化评价。表4参11。     

A study on the shade tolerance ofMuehlewbeckia complera

Muehlewbeckia complera was introduced to China in 2002 as indoor-hanging ornamental foliage plant. The experiment of the shade tolerance for this species was carried out in different light intensities (0.14–946.00 μmol·m⁻²·s⁻¹). After 40 days in experimental areas, leaf photosynthentic characteristics indexes ofM. complera in different photosynthesis active radiation (PAR) were measured with LI-COR6400 apparatus, such as the light compensation point, light saturation point, and maximum net photosynthesis rate, at the same time, the increments of total leaf area and leaf amount were measured. The results showed that the optimum light intensity range forM. complera was from 9.26 μmol·m⁻²·s⁻¹ to 569.00 μmol·m⁻²·s⁻¹ (463–28150 lx, relative humidity (RH) for 46–60%, temperature at 16–22°C). Under this condition, leaf photosynthetic efficiency was tiptop. AlthoughM. complera belonged to the moderate sun-adaptation plant species, the plant growth was inhibited when PAR increased to the level of 569.000 μmol·m⁻²·s⁻¹ or above.M. complera could sprout new leaves in photosynthesis active radiation of 0.16–19.22 μmol·m⁻²·s⁻¹ (8–961 lx), or 10 μmol·m⁻²·s⁻¹ for above 6 h. Foundation item: This study was supported by the Research Foundation of Northeast Forestry University. Biography: YUE Hua (1962-), female, Associate professor in Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Zhu Hong     

Analysis of organic acids in seleted forest litters of Northeast China

Larch(Larix olgensis), Manchurian ash(Fraxinus mandshurica), Korean pine(Pinus koraiensis) and White birch(Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were collected from the stands of the above 4 species in Laoyeling and Jianlagou experiment stations of Maorshan Exp. Forest Farm (45°12′–45°30′N, 127°30′–127°48′E), Northeast Forestry University, in early October 2002. Quantitative analysis and qualitative analysis were carried out on the organic acids existing in freshly fallen litters (L layer) and hemi-decomposed litters (F layer) of the four forest species by using Gas Chromatogram system. A wide variety of organic acids were identified, including oxalic, malonic, fumaric, succinic, maleic, malic, citric, C₁₆:O, C₁₈:O, C₁₈:1, C₁₈:2, C₁₈:3 and C₂₀:O acids. In respect of L litters of all samples, the oxalic acid content (over 30 mg/g) was the highest of the seven low-molecular-weight organic acids identified, while the content of oleic or linoleic (above 40mg/g) was found to be highest among the six high aliphatic acids identified. As to F litters, oxalic acid content was also the highest, followed by linoleic and oleic. For the same tree species or the same forest, the kinds and contents of organic acids in L litters were more abundant than that in F litters. Foundation item: This paper is supported by National Natural Science Foundation of China (30170768) Biography: SONG Jin-feng (1976-), female, doctor postgraduate, Harbin 150040, P. R. China. Responsible editor: Chai Ruihai     

造纸废渣和养分的改良对北部硬阔叶林土壤表面CO2通量的影响

Safe and economical disposal of paper mill sludge is a key consideration for forest products industry. A study was conducted to examine the effects of amendments of sludge and nutrients on soil surface CO₂ flux (R_s) in northern hardwood forests and to quantify the relat among R₅, soil temperature, and moisture in these stands. The experiment was a randomized complete block design that included sludge-amended, fertilized, and control treatments in sugar maple (Acer saccharum Marsh) dominated hardwood forests in the Upper Peninsula of Michigan, USA. Results showed that R_s was positively correlated to soil temperature (R²=0.80, p<0.001), but was poorly correlated to soil moisture. Soil moisture positively affected the R_s only in the sludge-amended treatment. The R_s was significantly greater in the sludge-amended treatment than in the fertilized (p=0.033) and the control (p=0.048) treatments. The maximum R_s in the sludge-amended treatment was 8.8 μmol CO₂·m⁻²·s⁻¹, 91% and 126% greater than those in the fertilized (4.6 μmol CO₂·m⁻²·s⁻¹) and control (3.9 μmol CO₂·m⁻²·s⁻¹) treatments, respectively. The R_s did not differ significantly between the fertilized and control treatments. The difference in R_s between sludge-amended and the other treatments decreased with time following treatment. Foundation item: The research was funded by a NCASI grant to S.T. Gower. Wang CK was supported by Innovated Talent Program of Northeast Forestry University (2004–07) Biography: WANG Chuan-kuan (1963-), male, Professor in the Ecology Program, College of Forestry, Northeast Forestry University, Harbin 150040, China. Responsible editor: Chai Ruihai     

Alkaloid variations in Catharanthus roseus seedlings treated by different temperatures in short term and long term

A study was conducted to investigate the effects of high temperature on variations of alkaloid metabolism in C. roseus seedlings in Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Heilongiang, China. 60-day-old C. roseus seedlings with 3-4 pairs of leaves were incubated in chambers with temperature of 30℃ and 40℃for short-term heat shock experiment and 20℃, 25℃ and 35℃ for long-term experiment. The contents of vindoline, catharanthine, vinblastine and vincristine in C. roseus leaves and root were checked at different temperatures in short term （1-6 h） and long term （1-16 d）. Results showed that under short-term heat shock, the contents of vindoline, catharanthine and vinblastine in leaves of the seedlings were higher at 40℃ than at 30℃, but after 6 h treatment, the contents of vindoline and catharanthine under the two temperatures came to the same level. Catharanthine was exclusively distributed in C. roseus roots and its content was increased by 40% after two hours incubation at 40℃, while increased slowly at 30℃ incubation and reached the highest value at 6 h. In the Long-term experiment, concentrations of monomeric alkaloids catharanthine and vindoline were higher at 20℃ than at 25℃ and had a sharp increase under the condition of 35℃. While for dimeric alkaloid, it showed that the higher the temperature, the earlier the peak value of vinblastine content appears. Vincristine had a continuous enhancement and attained 0.027 mg.g^-1 at 16th day under 35℃ condition which was higher than those in the other conditions. It was concluded that high temperature could promote the accumulation of different alkaloids in C. roseus and the accumulation characteristic is highly related to treatment time.     

白桦光合特性的研究

测定了3年生白桦的光合与呼吸作用对温度,湿度以及CO2浓度的响应;还测定了光补偿点,光饱和点和CO2补偿点。结果表明:在目前的空气CO2浓度下,光合和呼吸作用的最适温度分别是24℃和30℃;当相对湿度是80%时,白桦能维持较强的光合作用;呼吸作用与相对湿度无明显的相关性;光补偿点和光饱和点分别是25 molm-2s-1和1375 祄olm-2s-1;CO2补偿点是180 礚L-1;白桦在CO2浓度为2400 礚L-1时仍有吸收潜力。图4参19。     

露天煤矿排土场植被调查与自然恢复研究(英文)

通过分析辽宁省海州露天煤矿排土场植被组成、物种多样性及重要值的变化,研究了排土场植物群落恢复与演替的一般规律。结果表明:排土场共有植物63 种,分属于23 科,其中菊科15 种、豆科11 种、禾本科8 种;蒺藜+水稗草+猪毛菜、水稗草+大籽蒿+黄蒿、水稗草+披硷草+黄蒿+大籽蒿+黄花草木犀、芦苇+披硷草+水稗草+狗尾草分别是年限为5、10、20、40 梯田层群落的优势种群;重要值对植被重建中物种筛选有指示性,蒺藜在排土场人工恢复中可做为先锋种,披硷草、芦苇、水稗草可做为重要的优势种;排土场植被自然恢复速度缓慢,为了尽快改善生态环境,应该筛选并合理配置先锋植物和适生植物,进行植被重建,加强抚育管理,缩短演替进程。表2 参17。     

温度对大叶桃花心木(Swietenia macrophylla King)幼苗叶片的光合影响

本文研究了大叶桃花心木（Swietenia macrophylla King）一年生幼苗在经过夜温处理后的光响应曲线和在饱和光强下的CO2反应曲线.结果表明:在大气CO2浓度下,叶片的最佳光合作用温度在25-31℃之间,而在饱和CO2浓度下为31-35℃.在25℃以下光合速率开始降低,主要是由于羧化效率的降低,而当温度超过31℃时,光合速率下降,是因为羧化效率的降低和呼吸速率的增加.CO2浓度对光合的促进作用在低温下受到抑制,这意味着未来在CO2浓度增高的情况下,高浓度的CO2对热带常绿植物光合的促进在冬天低温情况下表现不十分明显.图4参23.     

Habitat selection of Guizhou golden monkey （Phinopithecus roxellanae brelichi）in Fanjing Mountain Biosphere Reserve, China

Guizhou golden monkey (Phinopithecus roxellanae brelichi) is a peculiar, rare and endangered species. It is distributed most narrowly and requires a rigorous habitat. In this study the habitats of Guizhou Golden Monkey were divided into three habitats: most suitable habitats, suitable habitats and marginally suitable habitats. The characteristics of the vegetation community, environmental factors and extreme environmental factors in the three habitats were systematically analyzed. The seasonal activity rule, activity area and the food characteristic of Guizhou golden monkey were also study at the same time. The results indicate that the evergreen and deciduous broadleaf mixed forest is the optimal living vegetation community for Guizhoug olden Monkey, and the suitable annual temperature is 8-15℃, the extremely lowest temperature is -2.5℃, the extremely highest temperature is 25℃, and the optimal living altitude is 1500-1700 m. In the same area, the higher the vegetation diversitythe more suitable it is for the life of Guizhou golden monkey. Temperature and food are the main habitat factors in determining the activity scope of the guizhou golden monkey community. The Altitude, temperature and the characteristics of the vegetation community are the main limitina factors for habitat selection.     

A mathematical verification of the reinforced-matrix hypothesis using the Mori-Tanaka theory

This article presents a theoretical verification of the reinforced-matrix hypothesis derived from tensor equations, σ ^W = σ ^f + σ ^m and ε ^W = ε ^f = ε ^m (Wood Sci Technol 32:171–182, 1998; Wood Sci Technol 33:311–325, 1999; J Biomech Eng 124:432–440, 2002), using classical Mori-Tanaka theory on the micromechanics of fiber-reinforced materials (Acta Metall 21:571–574, 1973; Micromechanics — dislcation and inclusions (in Japanese), pp 141–147, 1976). The Mori-Tanaka theory was applied to a small fragment of the cell wall undergoing changes in its physical state, such as those arising from sorption of moisture, maturation of wall components, or action of an external force, to obtain 〈σ ^A〉_D = ϕ·〈σ ^F〉_I + (1−ϕ)·〈σ ^M〉_D−I. When the constitutive equation of each constituent material was applied to the equation 〈σ ^A〉_D = ϕ·〈σ ^F〉_I + (1−ϕ)·〈σ ^M〉_D−I, the equations σ ^W = σ ^f + σ ^m and ε ^W = ε ^f = ε ^m were derived to lend support to the concept that two main phases, the reinforcing cellulose microfibril and the lignin-hemicellulose matrix, coexist in the same domain. The constitutive equations for the cell wall fragment were obtained without recourse to additional parameters such as Eshelby’s tensor S and Hill’s averaged concentration tensors A^F and A^M. In our previous articles, the coexistence of two main phases and σ ^W = σ ^f + σ ^m and ε ^W = ε ^f =ε ^m had been taken as our starting point to formulate the behavior of wood fiber with multilayered cell walls. The present article provides a rational explanation for both concepts.     

Effect of tool angles on the chips generated during milling of wood by straight router-bits

 The effect of tool angles on the shapes of chips generated by parallel-to-grain and end-grain milling was explored for China fir and maple under fixed spindle and feed speeds and cutting depth. The milling path was up-milling by straight router-bits with a diameter of 12 mm. The chip shapes could be distinguished as five types: spiral, splinter, flow, thin, and granules or powder. The flow and thin chips were generated most often (on a weight percentage basis) for all tool angles investigated for parallel-to-grain and end-grain milling of China fir and maple. More granule chips were produced with parallel-to-grain milling than with end-grain milling for both woods. The measured chip thickness (t′) was thicker than the calculated thickness (t _max). Thicker and longer maple chips were produced by end-grain milling than by parallel-to-grain milling. The tool geometries of 40°/15° (sharpness of the angle–rake angle), 50°/15°, and 60°/15° for China fir and 40°/25°, 50°/5°, and 60°/5° for maple produced relatively more flow chips with parallel-to-grain milling. Furthermore, the tool geometries of 40°/5°, 50°/15° and 60°/25° produced more flow chips (weight percentage) by end-grain milling of China fir and maple. Received: May 23, 2001 / Accepted: June 28, 2002 Acknowledgment This study was supported by a grant from the National Council of Science, Taiwan (NSC89-2313-B-415-011).     

在长白山生态系统中长期的高浓度CO2熏蒸对土壤酶的影响

从1999年到2006年在中科院长白山森林生态系统定位站（42°24＇N,128°28＇E,海拔738m）对长期高浓度CO2熏蒸对土壤酶活性的影响进行了研究.采用开顶箱（OTC）的方式对红松和长白松进行高浓度CO2处理, CO2浓度分别受控于高浓度CO2箱（500 μmol·mol^-1）、对照箱（370 μmol·mol^-1））和裸地（370 μmol·mol^-1）.经高浓度CO2（500 μmol·mol^-1）熏蒸8年后,土壤样品分别在2006年春季、夏季和秋季进行采集和分析.结果表明：在高CO2浓度（500 μmol mol^-1）条件下,转化酶活性除了红松夏季样品之外都是显著降低的;而脱氢酶活性却是增加的,但只有部分结果显著;长白松的多酚氧化酶活性都显著降低;过氧化氢酶活性在春季增加,而在其他季节均降低.总而言之,在高CO2浓度条件下,土壤酶的活性与树种有关.     

中国东北样带植被净初级生产力时空动态及其对气候变化的响应

根据净初级生产力(NPP)遥感估算模型,重建了中国东北样带(NECT)1982–2000 年间每月的 NPP 时空序列,分析了研究时段内 NPP 的时空格局特征及其与气候因子的关系。结果表明:(1)NECT 样带植被 NPP 的空间变化趋势同降水量的空间变化十分相似,由东到西逐渐降低,二者在空间上的相关性达到了 0.84(P<0.01),说明 NECT 样带的植被 NPP在空间分布上主要受水分趋动;(2)NECT 样带植被 NPP 的年际变化主要是由各年份夏季 NPP 的变化造成的,夏季对NECT 样带植被 NPP 的年际增长贡献率最大(67.6%),二者之间的相关性达到了 0.95(P<0.01);(3)NECT 样带的植被NPP 积累期主要发生在 5–9 月份,这 5 个月的 NPP 占了全年NPP 总量的 89.8%,整个夏季(6–8 月份)的 NPP 占了全年的 65.9%,冬季(12–2 月份)的 NPP 最低,基本为 0;(4)近 19 年来的气候变化促进了 NECT 样带的植被生长,从 1980年代到 1990 年代,NPP 显著增加,年代际相对增长率为 14.3%,平均年际绝对增长趋势为 4.6 gC m-2 a-1,相对增长趋势为 1.17%,这主要是由温度升高引起的。图 6 表 1 参 36。     

Geographic variation and genetic performance of Picea koraiensis in growth and wood characteristics

Eight provenances of 19-year-oldPicea koraiensis Nakai from the provenance trials of Maoershan (45°20′N, 127°30′E), Liangshui (47°10′N, 128°53′E) and Jiagedaqi (50°24′N, 124°07′E) in Northeast China were investigated to analyze the genetic variation in growth characteristics (tree height and diameter) and wood characteristics (tracheid length, tracheid diameter, tracheid wall thickness, annual ring width as well as wood density). Great variation in height growth and breast height diameter growth was observed among the provenances, and along with the increase of tree age, these provenances presented different geographic adaptability. The growth characteristics ofPicea koraiensis stand at age of 10 in Maoershan and Liangshui provenance trials had a positive correlation with longitude, and with increase of tree age to 15 and 19, the tree growth of the provenances displayed a significant positive correlation with latitude as well as altitude. For wood characteristics, great variation was also found among the provenances. There exists a close relation between growth characteristics and wood properties of the provenance. The height and breast height diameter growth of the provenance had a positive correlation with tracheid diameter and annual ring width, and a negative correlation with tracheid wall thickness and wood density. Genetic performance of the provenance in all above characteristics was also investigated in order to provide more useful information for comprehensive selection of this species for pulpwood and plywood production. Foundation item: The paper was supported by National Key Project of The State Forestry Administration. (96-011-01-06) Biography: WANG Qiu-yu (1957-), female, professor in College of Life Sciences, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Song Funan     

杨树冰核活性细菌溃疡病的病理和生理机制(英文)

在1997-1999年间,利用Bier, X.H、波钦诺克、王敬文、史瑞和等人的研究方法,分别对不同品种杨树如:美×青、A100、小黑14、黑小2、613、北京605等接种冰核活性细菌,并对接种前后树皮含水量、相对膨胀度、木质素、苯丙氨酸解氨酶(PAL)活性、电解质渗出率以及无机元素等进行了测定。结果表明:冰核细菌溃疡病发生后,树皮含水率降低,而膨胀度(RT值)升高;树皮内电解质渗出率增加,而在-4 C和5 C时渗出率最高;木质素的含量也有所增加,且与品种的抗病性呈正相关;苯丙氨酸解氨酶活性也有所增加,且与品种的抗病性呈正相关;Cu、Fe含量显著下降,K、Zn含量显著增加,但Mn、Ca、Mg含量变化不大。     

The runoff characteristics and harmonic analysis of the soil moisture dynamics in<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> stand

Robinia pseudoacacia stands act as a typical ecological protection forest in hilly semi-arid area of China. Two fields of surface runoff were separately set up inR. pseudoacacia stand and its clearcut area in the western Liaoning Province (18°50’–122°25’ E, 40°24’–42°34’ N) for measuring the characteristics of runoff and sediment as well as soil moisture dynamics. Contractive analysis of the two land types showed that there existed a significant difference in volumes of runoff and sediment between the sites ofR. pseudoacacia stand and its clearcut area. The runoff volume and sediment volume in clearcut are were much bigger than those inR. pseudoacacia stand, with an increase amount of 40%–177% for runoff and 180%–400% for sediment. Hydrograph of surface runoff of typical rainfall showed that the peak value of runoff inR. pseudoacacia stand was decreased by 1.0–2.5×10⁻³m³·s⁻¹ compared with that in its clearcut area, and the occurring time of peak value of runoff inR. pseudoacacia stand was 10–20 min later than that in its clearcut area. Harmonic analysis of soil moisture dynamics indicated that the soil moisture inR. pseudoacacia stand was 2.3% higher than that in clearcut area, and the soil moisture both inR. pseudoacia stand and its clearcut area could be divided into dry season and humid season and varied periodically with annual raifall precipitation. It was concluded thatR. pseudoacacia stand plays a very important role in storing water, increasing soil moisture, and reducing surface runoff and soil erosion. Foundation item: This paper was supported by Chinese “863” Plan Water-Saving Agriculture (2002AA2Z4321), the Key Knowledge Innovation Project (SCXZY0103), and The “Tenth-five” Plan of Liaoning Province (2001212001). Biography: GAO Peng (1967-), male, Dr. candidate, associate professor of Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan     

A new methodology for estimating forest NPP based on forest inventory data—A case study of Chinese pine forest

Accurately estimating forest net primary productivity (NPP) plays an important role in study of global carbon budget. A NPP model reflecting the synthetic effects of both biotic (forest stand age, A and stem volume, V) and climatic factors (mean annual actual evapotranspiration, E) was developed for Chinese pine (Pinus tabulaeformis) forest by making full use of Forest Inventory Data (FID) and dynamically assessing forest productivity. The NPP of Chinese pine forest was estimated by using this model and the fourth FID (1989–1993), and the spatial pattern of NPP of Chinese pine forest was given by Geography Information System (GIS) software. The results indicated that mean NPP value, of Chinese pine forest was 7.82 t m⁻²·a⁻¹ and varied at the range of 3.32–11.87 t hm⁻²·a⁻¹. NPP distribution of Chinese pine forests was significantly different in different regions, higher in the south and lower in the north of China. In terms of the main distribution regions of Chinese pine, the NPPs of Chinese pine forest in Shanxi and Shaanxi provinces were in middle level, with an average NPP of 7.4 t hm⁻²·a⁻¹, that in the southern and the eastern parts (e.g. Shichuang Hunan, Henan, and Liaoning provinces) was higher (over 7.7 t hm⁻²·a⁻¹), and that in the northern part and western part (e.g. Neimenggu and Ningxia provinces) was lower (below 5 t hm⁻²·a⁻¹). This study provides an efficient way for using FID to understand the dynamics of foest NPP and evaluate its effects on global climate change. Foundation item: This study was supported by the National Natural Science Foundation of China (Nos. 30028001, 49905005), National Key Basic Research Specific Foundation (G1999043407); the Chinese Academy of Sciences (KSC2-1-07). Biography: ZHAO Min (1973-), female, Ph. D. in Laboratory of Quantitative Vegetation Ecology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, P. R. China. Responsible editor: Zhu Hong     

Growth characteristics of multipurpose tree species,crop productivity and soil properties in agroforestry systems under subtropical humid climate in India

Multipurpose tree species （MPTs） were studied in an agroforestry arboretum under subtropical humid climate in Northeast India. Out of 12 MPTs planted under agroforestry systems, Acacia auriculiformis in spacing of 2 m × 2 m （2500 stems·hm^-2） could have the potentiality to meet the timber/fuelwood requirement due to its high wood production of 635 m^3·hm^-2 with mean annual increment （MAI） of 2.54×10^-2 m^3.treel.a^-1 in a short rotation period of 10 years. Thus, A. auriculiformis is a short rotation forest tree species suitable to grow in subtropical humid climate. On the other hand, at 16 years of age, Eucalyptus hybrid and Michelia champaca in spacing of 3 m × 3 m （1111 stems.hm^2） produced appreciably high timber volume of 315 m^3.hm^-2 and 165 m^3.hm^-2 with MAI of 1.77×10^-2 m^3.tree^-1·a^-1 and 0.92×10.2 m^3.tree^-1.a^-1, respectively. At 16 years of age, Gmelina arborea produced a timber volume of 147 m^3.hm^-2 with MAI of 1.47×10^-2 m^3.tree^-1.a^-1 followed by Samania saman （140 m^3.hm^-2）, Albizziaprocera （113 m^3·hm^-2） and Tectona grandis （79 m3.hm^-2） with MAI of 1.40, 1.13 and 0.78 × 10^-2 m^3 .tree^-1a^-1, respectively in 4 m × 4 m spacing （625 stems.hm^-2）. Gliricidia maculata and Leucaena leucocephala could be used as live fences around the farm boundary to supply their N-rich leaves for mulch as well as manure to crops. In agroforestry arboretum, direct seeded upland rice （Oryza sativa - variety, AR-11）, groundnut （Arachis hypogaea - variety, JL-24） and sesamum （Sesamum indicum - variety, B-67） were grown during the initial period upto 8 years of tree establishment. Under other MPTs, there was a reduction in crop productivity as compared to open space. After 8 years of tree establishment, horti-silvi and silvi-pastoral systems were developed and pineapple （Ananas comosus - variety Queen）, turmeric （Curcuma longa -variety RCT -1） and cowpea （Vigna sinensis - variety Pusa Barsati） as forage crop were raised. The productivity of p     

Response of seedlings of different tree species to elevated C02 in Changbai Mountain

Eco-physiological responses of seedlings of eight species,Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica andAcer mono from broadleaved/Korean pine forest, to elevated CO₂ were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998–1999). Two concentrations of CO₂ were designed: elevated CO₂ (700 μmol·mol⁻¹) and ambient CO₂ (400 μmol·mol⁻¹). The study results showed that the height growth of the tree seedlings grown at elevated CO₂ increased by about 10%–40% compared to those grown at ambient CO₂. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO₂ varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO₂ than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO₂. Foundation item: The project was supported by National Key Basic Development of China (G1999043400) and the grant KZCX 406-4, KZCX1 SW-01 of the Chinese Academy of Sciences Biography: WANG Miao (1964-), maie, associate professor in Institute of applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan     

Control of Lymantria dispar L. by biological agents

The experiment on control ofLymantria dispar L by using different kinds of biological measures, including nuclear polyhedrosis virus (NPV) ofLymantria dispar L., BtMP-342, sex-attractant as well as botanical insecticide, was carried out in the forest regions of Inner Mongolia in 2003. Two concentrations (2.632×10⁶ PIB·ml⁻¹ and 2.632×10⁷ PIB·ml⁻¹) ofLymantria dispar L. NPV were sprayed on the 2rd-instar-larvae ofL. dispar and 70% and 77.8% control effect were obtained respectively. BtMP0-342 was applied to the 3rd- and 4th-instar larvae and the control effect was around 80%. The sex-attractant provided by Canada Pacific Forestry Research Center also showed a good result in trappingL. dispar adults. The self-produced botanical insecticide, which was extracted from a kind of poisonous plant distributed in Daxing'an Mountains, China, exhibited a good control result in controlling the larvae ofL. dispar, and 82% mortality was observed when spraying primary liquid of the botanical insecticide on the 3rd–5th-instar-larvae in lab. Foundation item: This paper was supported by Natural Science Foundation of Heilongjiang Province (C0235) and Youth Foundation of Harbin City (0061218024). Biography: ZHANG Guo-cai (1964), male, Ph. Doctor Candidate, associate professor in School of Forestry, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Song Funan