The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke’erqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the aeolian sandy soil in different ratios. Two-year-oldPinus sylvestris var.mongolica seedlings and plastic pots were used in the experiment. The experimental results indicated that: 1) the peat and weathered coal could significantly improve the physical and chemical properties of aeolian sandy soil, and thus promoted the growth of seedlings; 2) the effect of peat on seedling growth, including height, base diameter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2%>10%>0 for root length, and 5%>2%>8%>10%>0 for biomass; 3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth ofP. sylvestris var.mongolica seedlings.
Four-armed airflow olfactometer was used to determining the foraging behavior ofPteroptrix longgiclava (Girault) (Hymenoptera: Aphelinidae) andEncarsia gigas (Tshumakova) (Hymenoptera: Aphelinidae) to the essential oils which emitted from the healthy bark ofPopulus pseudo-simonii×P. nigra, the infested bark injured byQuadraspidiotus gigas (Thiem & Gerneck), the body and scale of fixed 1st-instar-nymph ofQ. gigas. The results from these experiments showed that the volatile oils produced from the injured bark and from the scale of fixed 1st-instar-nymph had a higher attractive ability to female adults of the two species of wasps. The essential oil produced from the scale of the pest at dosages of 3–7 μL and the essential oil emitted by injured bark at dosages of 5–9 μL had a stronger alluring effect on the host searching behavior ofPteroptrix longgiclava. The essential oil from the body of fixed 1st-instar-nymph ofQ. gigas also had certain effect on the host locating effort ofPteroptrix longgiclava andEncarsia gigas. Those two wasps did not shown any reaction to the essential oil produced by the healthy bark of poplar.
Black locust (Robinia pseudoacacia L.) was the first forest tree species to be, imported from North America to Europe at the beginning of the 17th century. It is the most important fast-growing stand-forming tree species in Hungary. Black locust plantations can be successfully established in response to a range of economic and ecological opportunities. Plantation survival and productivity are maximized by matching the species’ growth characteristics with silvicultural options and land management needs. In the paper the sequence of forest tending operations in black locust stands is proposed, based on results of long-term stand structure and forest yield trials. Implementing good silvicultural plans and models will lead to profitable black locust stands and greater acceptance of the species by land managers. Black locust would also be a very useful species for energy productions as the related research results have been shown in the paper.
The spatial distribution of standing fine roots in tree rows of different species in a 12-year-old mixed stand of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) was studied by soil core sampling in early spring, 2001. It is found that ash and larch differ greatly in their belowground biomass distribution. Ash has much higher fine root biomass density in the soil than larch at stand level (with the max value of 4442.3 vs. 2234.9 g·m−3). Both tree species deployed more fine roots in their neighboring zone, suggesting a less intensive competition between roots of the two species. Both fine root biomass density and root length density of ash in the zone between larch tree rows are greater than that of larch in zone between ash tree rows, indicating that ash is more powerful than larch in belowground competition. The spatial distribution feature of roots favors the growth of ash in the mixed stand.
Soil samples were taken from rhizosphere zone and off-rhizosphere zone of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) in mixed and monoculture stands, and the nutrient concentration of N, P, and K was analyzed to study the effect of nutrients variation on yield improvement in the mixed stand. The result showed that: 1) The stand level total soil N concentration and available N in the mixed stand was similar to that in the monoculture stand of ash, but higher than that in monoculture stand of larch. The total N and available N concentration in rhizosphere soil of ash in the mixed stand was similar to that in the monoculture stand of ash, but the available N concentration in rhizosphere of larch in mixed stand was much higher than in its monoculture. 2) The stand level total P, total K concentration in the mixed stand was similar to that in monoculture stands of both species, but available P and K was more concentrated in the mixed stand than in the monoculture stands of ash. The rhizosphere available P and K of ash in the mixed stand was 44.1% and 13.5% (for the 9-yr-old stands) and 79.6% and 25.6% (for the 21-yr-old stands) higher than that in its monoculture. The improvement of soil P and K availability in the mixed stand is concluded.
Genetic diversity and genetic differentiation of natural populations ofPinus kesiya var.langbinanensis were examined by means of electrophoresis technique. Analysis of 9 enzyme systems including 16 loci showed that all the three natural populations of the pine were high in genetic diversity but, low in inter-population genetic differentiation. The proportion of polymorphic loci is 0.667, with each locus holding 2.13 alleles, averagely. The average expected and observed heterozygosity was 0.288 and 0.197, respectively. The gene differentiation among populations was 0.052, but the mean genetic distance was only 0.015.
Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao’ershan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously difference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude.
Genetic relationships of eight species of genusBetula were evaluated using ISSR marks. A total of 236 loci were generated from 17 ISSR primers. Percentage of polymorphic bands (PPB) varied from 5.93 to 19.92. The highest and the lowest level of genetic differentiation were detected inB. ovalifolia andB. maximowicziana Regel respectively. In these eight species, genetic diversity of birch (HT) was 24.38% and the genetic variation (GST) interspecies was accounting for 79.36% of total genetic variation. According to the cluster results of genetic distance, the eight species were classified into three groups asB. davurica, B. ovalifolia, B. platyphylla andB. pendula for one group;B. schmidtii, B. costata andB. ermanii Cham. var.communis for one group, andB. maximowicziana Regel for another group. The result of cluster is consistent with traditional morphological classification
The stimulative effect of trace elements on seed germination and seedling growth ofPinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varied concentrations at the nursery of Gardens Research Institute, Harbin, in 2000–2001. The experimental results showed that soaking seed with 1% and 0.2% concentrations of Mn element produced best result for seed germination, and the germination rate was increased by 9%–19% for the seeds treated with 1% concentration and 12%–14% for the seeds treated with 0.2% concentration compared with the control group. The seeds treated with boron element had lowest germination rate. For trace element topdressing, Mn and Mo elements presented good result for seedling growth and the treatment with low concentration was even better. The height or chlorophyll content of the seedlings with spray of low-concentration Mn and Mo element was much higher than that of untreated ones. In the contrast to the treating method of seed soak, topdressing (application of spraying on foliage) had evident effect on seedling growth.
The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The functions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of integrated climate effect within shelterbelt net were analyzed, through located observation of meteorological factors. Within the shelterbelt net, the area with more than 10% efficiency of omnibearing wind check was determined as benefited area. The analysis of yield and quality of crops indicated that the sheltering range of shelterbelt net was 25 times tree height. The mature heights of the various varieties of poplar composed the shelterbelts were determined according to their height growth. Based on the comprehensive analysis above, the suitable size of farmland shelterbelt net in Northeastern Plain of China was decided to be 400 m×400 m.
The survey on bird communities was conducted by the belt-style method in six different sample plots in the Honghua’erji Forests area in the northern Inner Mongolia in June 2001 and totally 28 bird species were recorded. Vegetation investigation was carried out in five 10 m×10 m quadrats at each plot. The asymptotic regression function formulae were adopted to identify the relationships between the vegetation coverage and the numbers of bird species and individuals. The analytical results showed that the changes of species number and density of bird as well as the formation of bird communities follow the changes of forest type and the total foliage. Both the number of bird species and their density decreased with the decrease of total foliage. The similarity of bird community was very low at the breeding time. In the same classification of cluster, no similarity was higher than 0.65, which indicated that the composition of species had a great difference between all the bird communities. The bird breeding density was closely related to forest growth stage. From the bare grassland ecosystem to climax ecosystem, the density of bird species showed a gradually increasing trend.
The genome sequence information in combination with DNA microarrays promises to revolutionze the way of cellular and molecular biological research by allowing complex mixtures of RNA and DNA to interrogated in a parallel and quantitative fashion. DNA microarrays can be used to measure levels of gene expression for tens of thousands of gene simultaneously and take advantage of all available sequence information for experimental design and data interpretation in pursuit of biological understanding. Recent progress in experimental genomics allows DNA microarrays not simply to provide a catalogue of all the genes and information about their function, but to understand how the components work together to comprise functioning cells and organisms. This brief review gives a survey of DNA microarrays technology and its applications in genome and gene function analysis, gene expression studies, biological signal and defense system, cell cycle regulation, mechanism of transcriptional regulation, proteomics, and the functionality of food component.
Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio forPinus thunbergii trees and stands were deduced from stem bending theory and coefficients characterizing wind profile, distribution of branches and optical stratification porosity. The results showed that if the value of constant β in the branch distribution-model equals the attenuation coefficient αs in the wind profile model for a single tree crown, then the parameter H/D1.3 3 (height over stem diameter cubed) can be used to compare and evaluate the risk-ratio of wind damage for individual trees. The same method can be applied to stands using the coefficient of wind profile in a stand, i.e. attenuation coefficient α, the coefficient from distributions of optical stratification porosity, i.e. extinction coefficient ν, and the parameter D1.3 3. The application of parameter H/D1.3 3 and the process of determining risk ratios of wind damage for stands were also given in the paper.
Forest certification is considered to be complementary to forest management policies and takes a significant effect on forest product trade. In recent decade, it has been followed with interest and approved by governments and forestry departments in the world. This paper analyzes the influence of forest certification on forest product trade in the world, including the interest in certification in exporting countries and importing countries, trade flow and business competition, and the demands for Certified Forest Products (CFPs) and also discusses the influence of forest certification on forest product trade in China.
Based on the analysis of the current situation of Chinese forestry and a series of ecological, environmental, economic, and social problems, this paper emphasized on the importance of forests in social and economic development in China The author pointed out that sustainable development, particularly the sustainable development of forestry, is the inevitable choice to solve the problems of ecological environment and social economics. The objectives, criteria, and strategies of sustaining forestry were also demonstrated and expounded, from the viewpoints of ecology, economics, and sociology.
This paper makes a brief introduction of the ecological environment, forestry achievements, and the existing questions of Jilin Province. The task of forest ecological network and eight questions demanding prompt solution were discussed based on the present situation of forestry in Jilin Province. The author also made prospects for future application of bio-technique, information technology, new material technology and nuisance-free forest health technology in forest ecological network.
Since 1950, 700 plots were established in the alpine and canyon region of western Sichuan. The distribution characteristics and the relationships between forest succession and environmental gradients were studied. The results showed that the main tree species werePicea andAbies in this region, and there were more than 90 forest types.Abies forests mainly distributed in the middle and upper reaches of rivers and their branches, andPicea forests mainly distributed in the wide valleys and on half-shaded and half-sunny slopes. The natural regeneration was poor under primitive spruce and fir forest canopy, but was good in the spruce and fire forest gap. The relationship between forest succession and vertical gradient was closely related to the relationship between forest succession procession and plant synusia under primary forests. Human activities could promote and postpone succession process. The results of expanding regeneration were often influenced by topography, vegetation and wind direction.
Chouioia cunea Yang is a natural enemy for many kinds of crops and forest pests, particularly forHyphantria cunea Drary, which is an international quarantine pest. The experiment of rearingChouioia cunea with Tussah (Silkworm) pupa were carried out by “three-cut method” and inoculating method. The results showed that three-cut method is effective way for breedingChouioia cunea, with a parasitical rate of 95%. The biological characteristics and the life cycle ofChouioia cunea were observed and described and more hosts ofChouioia cunea were found. “Three-cut method” as a new technique of rearingChouioia cunea has been put into practice.