Three antibiotics ampicillin, carbenicillin, and cefotaxime were evaluated for their effects on induction, growth, and differentiation of organogenic calli, as well as rooting of regenerated shoots of three loblolly pine (Pinus taeda L.) genotypes. Of the antibiotics administered, cefotaxime maximally increased the frequency of callus formation and growth rate of organogenic calli, carbenicillin maximally increased the frequency of shoot regeneration and the average number of adventitious shoots per piece of organogenic callus, ampicillin maximally decreased the rooting frequency of regenerated shoots and mean number of roots per regenerated shoot, in comparison with antibiotic-free media. Compared with the control, ampicillin minimally increased the frequency of callus formation, cefotaxime minimally increased the frequency of shoot regeneration, and carbenicillin minimally decreased the rooting frequency of regenerated shoots in three loblolly pine genotypes tested. All three antibiotics increased the frequencies of callus formation and shoot regeneration, and reduced the rooting frequency of regenerated shoots suggested that the establishment of an efficientAgrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into loblolly pine need to select a suitable antibiotic. This investigation could be useful for optimizing genetic transformation of conifers.

Soil water stress was studied on the potted seedlings of five dominant tree species (Pinus koraienes Sieb. et Zucc.,Fraxinus mandshurica Rupr.,Juglans mandshurica Maxim,Tilia amurensis Rupr. andQuercus mongolica Fisch. ex Turcz) from the broadleaved/Korean pine forest in Changbai Mountain. Leaf growth, water transpiration and photosynthesis were compared for each species under three soil moisture conditions: 85%–100% (high water, CK), 65%–85% (Medium water, MW) and 45%–65% (low water, LW) of 37.4% water-holding capacity in field. The results showed that the characteristic of typical drought-resistance of the leaves is significantly developed. The net photosynthetic rate and water use efficiency ofFraxinus mandshurica were higher in MW than those in CK. But for the other four species, the net photosynthetic rate and water use efficiency in CK were lower than those in MW and LW. The transpiration rate responding to soil moistures varied from species to species.

The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C₄ shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6% soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The decrease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO₂ assimilation rate. The stomata played a relatively small part in determining the net CO₂ assimilation rate for the same seedling. The relationship between net CO₂ assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO₂ assimilation rate by waters tress treatments, therefore intrinsic water-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO₂ assimilation rate. Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range.

Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjian Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO₂ extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extraction conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 °C. The velocity of flow of liquid CO₂ was at 10 kg/h. The pressure and temperature in separation vessel were at 5.5 Mpa and 50 °C, respectively.

Because of the distinction of soil property and humus content, soil water content is not ideal to indicate whether it is suitable to the growth of plant. Mainly based on the PF-a numerical value denoting the water regime of soil and connected with the growth of plant, the study combined the moisture percentage of soil with PF to research in quantity the interrelation between the moisture percentage and PF in different succession phases of subalpine dark coniferous forest in Gongga Mountain. The results showed that: (1) In the same PF value, the moisture percentage in humus horizon increased gradually with the development of the succession of the dark coniferous forest; The moisture percentage of over-mature forest was the highest and>mature forest>half-mature forest>young growth forest; (2) With the increase of soil depth, the soil bulk density increased and the moisture percentage decreased, but the difference in the percentage of moisture was not notable in different succession phases. (3) In different succession series, the vegetation affected the soil water characteristics by increasing the soil organic matter, improving the soil construction, receding the soil bulk density and enhancing the soil porosity; (4) The humus horizon of the dark coniferous forest soil has the highest water holding capability in this region.

GenusEurydoxa Filipjev in China is reviewed and noted for the first time. Based on the present study, two species are recognized, includingrhodopa Diakonoff andadvena Filipjev. All available information for the species is reviewed and provided.

Embryo of lilacs (Syringa L) culture in vitro and the rapid propagation were studied. The orthogonal experiments, including the selection of basal medium, embryo age and other factors such as sugar, benzyladenine (BA), naphthalene acetic acid (NAA) and glutamine (Gln), were carried out. The results indicated that the optimal medium for embryo culture was Monnier medium supplemented with NAA (0.001 mg·L⁻¹), BA (0.1 mg·L⁻¹), sugar (50 g·L⁻¹), and Gln (400 mg·L⁻¹), with a germination rate of 91.7% at least; the optimal embryo age was 50 d; and Gln had significant effects on the germination rate of embryo. Moreover, the optimal medium for subculture was MS+BA (2 mg·L⁻¹)+NAA (0.001 mg·L⁻¹)+Gln(0.5 mg·L⁻¹), with the propagation coefficient of 3.6 at least.

Endophytic fungi are widely found in almost all kinds of plants. Many endophytic fungi can produce some physiological active compounds, which are same to or analog to those isolated from their hosts. Producing physiological active compounds through microbial fermentation can give a new way to resolve resource limitation and to find out alternative source. Through the methods of organic solvent extraction, thin layer chromatography (TLC) and column chromatography, compound I was isolated, purified from the liquid fermentation metabolites of the taxoid-produced endophytic fungi (Altemaria. alternata var.taxi 1011 Y. Xiang et LU An-guo) that was screened from the bark ofTaxus. cuspidata Sieb. et Zucc., Compound I was identified as one kind of taxoids type III, based on the analyzing results by using the methods of ultraviolet spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). This study provides a completed method for separation and purification of the endophytic fungi as well as structure identification of its fermentation metabolite.

Bird communities were surveyed in natural deciduous forest of both slope area and valley area at Mt. Gyebangsan (37°40′ 30″ N, 128°30′1″ E), Gangwon Province, South Korea in winter, spring, summer and autumn from September 2000 to November 2001. The investigating results showed that there existed differences in the bird species composition, richness, bird species diversity, guild structure between slope area and valley aree, and the vertical forest structure, especially coverage of understory, and diameter at breast height (DBH) distribution also had significant difference between the two study areas. The differences in habitat structure between the areas are very likely to have influences on how birds used the available habitat.

Poplar is one of the dominant tree species for the establishment of fast growing plantations in Shandong Province. Eighteen poplar clones belonging toPopulus aigeiros section were introduced from Italy. Turkey and domestic regions.Populus deltoides cv. ‘Lux’ I-69/55 (I-69), which was widely used in Shandong Province, China, was taken as control clone (I-69). Following a randomized complete block design, seedling test and controlled afforestation trials were carried out at Juxian County, Caoxian County and Laiyang City. The results showed that the poplar clone (Populus x euramericana cv. ‘102/74’) namely 102/74, performed well both in terms of adaptability and growth rate. The mean height of 13.9 m (H), diameter at breast height of 18.0 cm (DBH) and volume growth of 0.1445 m³ (V) were 2.2%, 21.6% and 52.9% higher than those of I-69 (CK), respectively, at the age of 5 years at three experimental sites. Moreover, the clone can be propagated easily and showed high resistance to poplar disease, pest as well as salinity and had longer growing period. Furthermore, wood basic density and fiber length of new poplar clone (102/74) were as same as I-69 (CK). It was concluded that the selected clone (102/74) was ideal for the establishment of fast-growing poplar plantations, especially for the pulpwood plantations in Shandong Province.

Next to CO₂, methane (CH₄) is the second important contributor to global warming in the atmosphere and global atmospheric CH₄ budget depends on both CH₄ sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH₄ in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH₄ in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH₄ oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH₄ oxidation, and related natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases concentrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenous aluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that CH₄ consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil. CH₄ oxidation was also particularly sensitive to soil C/N, Ambient CO₂, CH₄ and N₂O concentrations, tree species and forest fire. In most cases, anthropogenic, disturbances will decrease atmospheric CH₄ oxidation, thus resulting in the elevating of atmospheric CH₄. Finally, the author pointed out that our knowledge of atmospheric CH₄ oxidation (consumption) in, forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH₄ oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studies further on CH₄ oxidation in various forest soils of different areas.

Nitrogen is one of the most important elements that can limit plant growth in forest ecosystems. Studies of nitrogen mineralization, nitrogen saturation and nitrogen cycle in forest ecosystems is very necessary for understanding the productivity of stand, nutrient cycle and turnover of nitrogen of forest ecosystems. Based on comparison and analysis of domestic and international academic references related to studies on nitrogen mineralization, nitrogen saturation and nitrogen cycle in recent 10 years, the current situation and development of the study on these aspects, and the problems existed in current researches were reviewed. At last, some advices were given for future researches.

The paper presents a method of using single neuron adaptive PID control for adjusting system or servo system to implement timber drying process control, which combines the thought of parameter adaptive PID control and the character of neural network on exactly describing nonlinear and uncertainty dynamic process organically. The method implements functions of adaptive and self-learning by adjusting weighting parameters. Adaptive neural network can make some output trail given hoping value to decouple in static state. The simulation result indicates the validity, veracity and robustness of the method used in the timber drying process

According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species diversity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densities of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Comparing with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.

An exploratory study was conducted on the housing pattern and food habit of theMro tribe in Bandarban region, Bangladesh, highlighting their indigenous knowledge. The study was carried out with respect to three income groups. A total of 36 households (12 from each income groups) were assessed using different participatory appraisals through semi-structured questionnaires. A special type of indigenous knowledge on housing pattern and food habit was explored in theMro community, which correspond to the severe dependence on forest resources.

Changbai Mountain forest area is not only is a national timber base but also a green ecological defense for Songliao Plain of NE China. The Natural Forest Protection Project of this area has an important bearing on the social and economic sustainable development of Jilin Province or even the whole forest area in NE China. This paper summarized general conditions of natural forest in Changbai Mountain state-owned forest area and put forward six problems need to be urgently solved and five strategic suggestions on natural forest protection and sustainable management.