Relative windspeed reduction was measured behind nine relatively narrow, homogenous tree windbreaks with porosities between 0.13–0.33, and behind 28 combinations of model stubble barriers representing 25 different optical porosities (0.00–0.80). The optimum porosities observed were 0.25 and 0.13 for tree windbreaks and stubble barriers respectively. Based on the relationship between windbreak structure (optical porosity) and wind reduction, the chief indices for determining spacing interval, i.e., the windbreak structure index (δ) and the parameter of microclimate, represented by the problem wind (L rp), were determined. Additionally, investigations on shelterbelt trees were carried out, and stem-analysis techniques were used, to develop a method for determining the mature height of tree windbreaks (H 0). Optimal spacing intervals between windbreaks could be predicted from the indices of a given windbreak structure, percentage of reduction of windspeed desired and tree growth model. A hypothetical example for determining the spacing interval of principal poplar windbreaks is given at the end of this paper. The results can be applied not only to tree windbreak design but also to other plant materials and artificial barriers for wind protection.
A protocol is presented for genetically engineering loblolly pine (Pinus taeda L.) using particle bombardment. This protocol enabled the routine transformation of loblolly pine plants that were previously difficult to transform. Mature zygotic embryos were used to be bombarded and to generate organogenic callus and transgenic regenerated plants. Plasmid pB48.215 DNA contained a synthetic Bacillus thuringiensis (B.t.) crylAc coding sequence flanked by the double cauliflower mosaic virus (CaMV) 35S promoter and nopaline synthase (Nos) terminator sequences, and the selectable marker gene, neomycin phosphotransferase II (nptil) controlled by the promoter of the nopaline synthase gene was introduced into loblolly pine tissues by particle bombardment. The transformed tissues were proliferated and selected by kanamycin resistance conferred by the introduced NPTIi gene. Shoot regeneration was induced from the kanamycin-resistant callus, and transgenic plantlets were then produced. The presence of the introduced genes in the transgenic loblolly pine plants was confirmed by polymerase chain reactions (PCR) analysis, by Southern blot analysis, and insect feeding assays. The recovered transgenic plants were acclimatized and then established in soil.
This paper makes analysis of published articles and books on landscape ecology in the 1990s through literature collection. The analytical results showed that the study of landscape ecology had made a great advance during the past decade in China. By incomplete survey, Chinese researchers at home and abroad published 619 scientific articles and 13 monographs on landscape ecology in the 1990s, and most of them (more than 90%) were published in Chinese with English abstracts. The published articles on basic theory accounted for 39.6% (245 articles), and those concerning application and methods accounted for 36.8% (228) and 23.6% (146), respectively. According to the objects of research, the published articles on landscape ecology were classified into nine catalogues. The urban landscape ranks first in terms of number of published articles, accounting for 13.4% of the total, followed by regional and river basin landscape, cold and arid landscape, forest landscape, habitat and bio-diversity landscape, agricultural landscape, wetlands, suburban landscape, and vegetation landscape. Based on the analysis, some discussions were made on the existing problems and development trend of landscape ecology study in China.
The paper deals with the stand structure and yield of black locust (Robinia pseudoacacia L.) forests mixed with white (Populus alba L.) in various proportions, partly applying a new methodological approach. The main stand structure and yield factors were determined separately for each species, measured stem by stem, using the volume functions prepared for each species. The ratio of the volumes of the species (A and B) in mixed and in pure stands (based on volume tables) was determined. A close relationship has been found between the ratio by relative total volume and the proportion (by the number of stems) of the species. The relative surplus in the volume of the mixed stands varied between 1.24–1.55 at the age of 16 compared to the control, i.e. the yield of pure stands of the species concerned. The trial has also proven that if two species have a fast initial growth rate and a similar rotation age, they can be planted in mixed stands resulting in mutual advantages.
A study of the storage dynamics in the mixed broadleaved and Korean pine forests was carried out in the Changbai Mountains, Jilin Province, P.R. China. The modifying law of fallen trees was the storage dynamics of the existing fallen trees and the annual input in the mixed broadleaved and Korean pine forest. The current storage of fallen trees was 16.25 t·hm−2 in the initially, but after 100 years, 85% of the storage in dry weight was decomposed, and little material was left after 300 years. The average annual input of fallen trees was 0.6 t·hm−2 and it increased with time to 31.0 t·hm−2 after 200 years, which was maintained until the climax community ended. The total storage of fallen trees increased in the early stage. The decomposition of fallen trees eventually reached equilibrium with storage being identical with the annual input of fallen trees.
Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species richness (s), Simpson index (D), and Shannon-Weiner index (H) were used to study the biodiversity and the hierarchical classification was carried out by the methods of TWINSPAN and DCA ordination. The results showed that the components of flora were complex and dominated by the temperate type in the riparian plant communities. Species diversity was not different between the communities, but Shannon-Weiner indexes of different layers in some grassland were significantly different. TWINSPAN and DCA indicated that riparlan plant communities distributed along the gradient of moisture.
Four types of soils, including brown coniferous forest soil, dark brown soil, black soil, and black calic soil, sampled from three different places in northeast China were used in this test. The functions of two root-derived organic acids and water were simulated and compared in the activation of mineral nutrients from the rhizosphere soil. The results showed that the organic acids could activate the nutrients and the activated degree of the nutrient elements highly depended on the amount and types of the organic acid excreted and on the physiochemical and biochemical properties of the soil tested. The activation effect of the citric acid was obviously higher than that of malic acid in extracting Fe, Mn, Cu, and Zn for all the tested soil types. However, the activation efficiencies of P, K, Ca, and Mg extracting by the citric acid were not much higher, sometimes wven lower, than those by malic acid. The solution concentration of all elements increased with increase of amount of the citric acid added.
The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (128°28’E and 42°24’N, Jilin Province, P.R. China) in August 2001. The basic characteristics of turbulence, such as turbulence intensity, atmospheric stability, time scales, and convection state, near the forest floor were analyzed. It is concluded that the airflow near forest floor is characterized by high intermittence and asymmetry, and the active and upward movement takes the leading position. Near forest floor, the vertical turbulence is retained and its time scale and length scale are much less than that ofu, v components. The eddy near forest floor shows a flat structure and look like a ‘Disk’. Buoyancy plays a leading role in the generation and maintenance of local turbulence.
The survey of seed dispersal ofRhodiola sachalinensis was carried out in Changbai Mountain in 1997. It was discovered that the dispersal of seed is not equal in all directions, but concentrates in the East and North to the cluster.Rh. sachalinensis seeds for germination test were collected from Changbai Mountains area (Antu County, Jilin Province) and Dahailin Migrating Conservation Base (Dahailing Forestry Bureau, Heilongjiang Province). The seeds were treated with 2% KNO3 for 10h and 0.02% GA3 for 5h immediately after the collection. The germinating rate (85.33%) of the seeds from Dahailin was obviously higher than that (72.66%) from Changbai Mountains. After being stored at 0–5°C for 10 months, the seeds were treated again with the same concentration of hormone mentioned above for germination test. The experimental results showed that there was almost no difference in germinating rate between newly collected seeds and 10-month storage seeds, which indicated that low-temperature storage can extend the life of seeds, and that the germinating rate increases with increasing of hormone concentration.
Two species of babblers, Black-lored Babbler (Turdoides sharpie) and Arrow-marked Babbler (Turdoides jardeneii) are sympatric around lakes Naivasha and Nakuru, Kenya. This study was carried out to assess the habitat partitioning mechanisms of the two species around Lake Naivasha area. The characteristics of habitats used by seven groups of each species were studied along the shorelines of lakes Naivasha and Oloiden. The two species differed significantly in the habitat characteristics. Arrow-marked Babbler is restricted to shorelines with dense tree and ground vegetation cover while Black-lored Babbler occupies open areas with sparsely distributed small trees and short ground vegetation cover. Observations on the feeding habits and social behaviours of the two species are also discussed.
This study were carried out in the Experimental Forest (37° 48′ 10″ N, 127° 48′ 50″ E) of Gangwon Forest Development Institute, Gamjeong-ri, Chuncheon, Gangwon-do Province, Korea from Dec. 1999 to Jul. 2002. Eight individuals (three males and five females) of hazel grouse were captured and they were marked with a 14-g necklace-type transmitter. The surveying results showed that females were more active than males throughout the year, but males were more mobile than females in spring. The degree of movement for females and males was similar from summer to winter. The overlap degree of habitat was very large from spring to autumn. Hazel grouse had greater shifts in area use in winter. They used similar area from spring to autumn, made a shift in their habitat use in winter, and then shifted back to the previous habitat.
Based on the literature reviews and questionnaire, field survey on the species, feces, and tracks in non-snow season and snow season of Korean musk deer from February to December of 1999 in South Korea (Cultural Properties Administration 1999), the authors summarized the change of distribution area and number of Korean musk deer from 1950s to 1999. The results showed that the distribution area of Korean musk deer (Moschus moschiferus parvipes) was sharply decreased from 1950s to 1999 in South Korea. Due to the road and forest road construction in the habitat of Korean musk deer, the musk deer habitats were fragmented and lost. And the illegal capture for economic benefits was the main reason of decreases in number of individuals and habitats of this species. Forest roads in high elevation area were also used as the passages for illegal captures. For the conservation and protection of Korean musk deer, strict regulation of illegal capture is urgently needed.
In three scenic spots (Golden Whip Crag, General Rock, and Treasure Box for Celestial Books) of Zhangjlajie National Forest Park, four sample plots were selected to investigate the number of tree skin scars camaged by visitors and the quantity and species of vegetation. The analysis results indicated that trees located along the sides of roads are seriously cut by visitors, especially in Yellowstone Village and Gold Whip Stream areas. The wounded degree was mainly related to tree species, smoothing degree, and the distance from tree to the edge of roads. The impacting degree of tourism activities on vegetation, was confirmed by impact Vegetation index (l VI). On the three most visually impacts sites, the range ofl VI value varied from 59.4% to 87.5%. This showed that the vegetations of the sides of the trails were impacted seriously. To these problems, some suggestions are proposed for the park’s management on visitors.
The samples of licorice (Glycyrrhiza uralensis Fisch.) from 14 different cultivated areas were determined by the method of high Performance Capillary Electrophoresis (HPCE) for the contents of glycyrrihizic acid (GA) in root. The results showed that the licorice plants come from various cultivated areas of China has different contents of GA. The GA content of licorice from Zhaodong in Heilongjiang Province is the highest, followed by those from E’tuoke, Chifeng, and Hangjin Banner in Inner Mongolia. Some suggestions for establishing the production base of licorice were put forward based on the study.
The determination method of 10-hydroxycamptothecin inCamptotheca acuminatu fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column with mobile phase of acetonitrile-water (3:7, V:V), flow rate 1 mL·min−1 and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits ofC. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60°C for 50 minutes.
This paper cursorily introduced some ideas and approaches of ecosystem health researches. The definition and connotations of forest ecosystem health have also been expatiated. Defining forest ecosystem health has been discussed from the management objective approach, and integration approach. To impel the relative researches in China, more attention on the properties of a forest ecosystem should be paid.
Since bamboo has the advantages of straight grain, beautiful color, high strength and toughness, and excellent abrasion resistance, bamboo-based panels have been widely used in the fields of vehicle, construction, ship building, furniture, and decoration to partly take the place of wood, steel, plastic etc in China. This paper briefly described the basic component units, including strip, sliver, and particle, of bamboo-based panel and pointed out that to design the structure of bamboo-based panels should follow the principle of symmetric structure, surface foming method, and structuring principle of equalizing stress. According to the processing methods and formation of component units, the authors classified the bamboo-based panels in China into 13 types and presented the manufacturing technique and uses of the bamboo products, such as plybamboo, bamboo flooring, and bamboo-wood composite products in detail. In the last part of the paper, much information were offered on the output, market, and selling prospect of each type of bamboo-based panels.
China is the country with most widely distributed loess area in the world, and its loess area accounts of 6.63% of total nation land area. The landslide disaster occurs frequently for complex natural condition and becomes major factors hindering the social and economic development of loess regions. Through different indexes, the authors divided the landslides into 9 principal types and analyzed the distribution characteristics of loess landslide in time and space, the affecting factors and mechanism of landslides. It is pointed out that time and spatial distributions of landslides are closely correlative to topographic and geomorphic conditions, earthquake and rainfall, and the key influencing factors include topography, geomorphology, new tectonic movements, earthquake activity, surface water, ground water and human activities. The authors emphasized that the loess landslide was an urgent task for sustainable development in the loess zone.
Luseweilei is an easily-bursted microcapsule insecticide. A test of effectiveness of the insecticide to control the larvae ofDendrolimus superans T. was carried out in larch forest in Baoan Forest Farm of Nehe City, Heilongjiang Province, in April 2001. The solutions of different concentrations (1∶150, 1∶250, 1∶350, and 1∶450 Luseweilei: water) were sprayed on the larch trunk before the overwintering larvae climbing on trees and the spraying lengths (height) designed were 1.0, 2.5, and 3.5 m high from ground. The control result showed that spraying 150-, 250-, and 350-fold solutions of the insecticide all produced a good control result, with a mortality rate of 97%, but the 450-fold solution only produced 70% mortality. It is concluded that this insecticide can be used as a kind of good insecticide to control the overwintering larvae ofD. superans in spring. Spraying 350-fold solution of easy-burst microcapsule insecticide and one meter spraying length are recommended for the future application.