Biomedical subjects

Fengqi Jiang

Publications and source records attributed to Fengqi Jiang.

14 recordsLinked to original sources

PubMed2004

[Influence of shelterbelts structure on snow distribution pattern in shelternets in Northeast China].

The amount of snow that falls in farmland during winter in Northeast China is the important source of soil water in farmland, so the influence of shelterbelt structure on snow distribution pattern is the key problem in order to adjust structure of shelterbelts according to porosity in management practice. Based on snow depths in shelternets composed of shelterbelts with three levels of porosity, which were shelternet No. 1, shelternet No. 2, and shelternet No. 3, the snow distribution patterns in farmland were studied. The results showed that the structure of shelternet had great influence on snow distribution in farmland. With different levels of porosities, spatial pattern of snow distribution were obviously different in three shelternets. The more variant in porosity, the more obvious difference in snow distribution pattern, and the best uniformity of snow distribution appeared in shelternet with porosity of phi 2w = 0.579, phi 2s = 0.268, in which snow depth in farmland was relative even and the variability of snow depth was the least. Consequently, the relationship of porosity of shelterbelt with snow distribution pattern could be used to guide structure adjustment and optimization management of shelterbelts.

Agriculture↗

PubMed2004

[Comprehensive evaluation and selection of urban eco-engineering virescent trees in Shenyang City].

Urban virescence eco-engineering is the core of urban eco-environmental construction, which can promote urban sustainable development. In urban virescence eco-engineering, the comprehensive evaluation of ecological adapt-ability and ecological effect of urban plants is the scientific basis of rational application and selection of urban garden plants. The ecological effect and integrative functions of urban virescence eco-engineering depend upon the selection and layout of garden plants. Using the methods of garden expert consultation and evaluation, this paper established systematically integrative evaluation and application indices of virescence plants in Shenyang City, from the aspects of ecological adaptability, ecological effect, beautification effect, resistance to plant diseases and insect pests, anti-pollution and economic results. According to garden experts evaluation and location of Shenyang, 200 sorts of virescence trees were evaluated and classified on the basis of the comprehensive evaluation system of virescence trees, and using cold resistance, drought resistance, barren resistance, plant diseases and insect pests resistance, anti-pollution, ornamental quality and ecological effects as the indexes. The results showed that the number of first rank trees was 58, the second was 93, methods of third was 38, and the fourth was 11, ranked by integrative performance.

China↗

PubMed2004

[Vegetation restoration in western Liaoning hilly region: a study based on succession theory and degradation degree of ecosystem].

Analysis with some habitat indexes of different succession stage, this paper quantitatively measured the degradation degree of degraded ecosystems in this region. The results showed that the average dissimilarities between natural Quercus forest, natural Chinese pine (Pinus tabulaeformis) forest and Populus-Quercus forest in Nanliuzhangzi forestry centre and Chinese pine plantations in Niuheliang region and Qitian forestry centre were 0.655, 0.665, 2.029 and 3.919, respectively, and as a whole, the dissimilarities represented the places of the forests in the process of ecosystem succession/degradation. It was also showed that most habitats were degraded to the stage between shrubbery and pioneer arbor forest, and closer to the succession stage of pioneer arbor forest. Some suggestions were made for the management of the existing plantation and the construction of mixed forest, e.g., to increase the proportion of shrubbery and pioneer arbor species, especially that of nitrogen fixation tree species. The plant species list of several main vegetation types in western Liaoning we offered could provide scientific reference for the vegetation restoration and the management of pure Chinese pine plantation in this region.

China↗

PubMed2004

[Major features of decline of Pinus sylvestris var. mongolica plantation on sandy land].

In view of the decline of man-made sand-fixation forest of Pinus sylvestris var. mongolica in Zhanggutai sand land of Liaoning Province, this paper studied the major characteristics of the decline. The appearance of the declining man-made sand-fixation forest of Pinus sylvestris var. mongolica was grey green, its needle leaf was very thin, the blooming and fruiting rate was low, the average quantity of cones per tree was only 10.4-16.5, with only 6.96 g to 7.39 g per thousand seeds, and there were many empty and astringent seeds. The seasonal dynamics of nutrients in 2-year-old pine needle leaf was similar, i.e., the N and P contents decreased, while K content increased, showing that the nutrient cycle was imbalance. The chlorophyll content in 2-year-old needle leaf of declined forest was high, while that in 1-year-old healthy forest was also high but with a wide increasing range. The infected harm of shoot blight was the clearest mark to the decline of man-made sand-fixation forest of Pinus sylvestris var. mongolica. After the forest declined, the height and the DBH of the pine trees decreased evidently, and the structure of DBH distribution moved "left". The quantity of weak pine trees increased by 15.9%-27.2%, the roots decreased by 22.9%-28.9%, and the absorbing roots (diameter < 0.5 cm) decreased most seriously.

Agriculture↗

PubMed2004

[Decline regularity and causes of Pinus sylvestris var. mongolica plantation on sandy land].

The study showed that the decline of Pinus sylvestris var. mongolica plantation out of its natural distribution area was a phenomenon of premature senility. The infected harm of shoot blight was the direct cause of Pinus sylvestris var. mongolica dying, but wasn't the basic reason. The decline of Pinus sylvestris var. mongolica was caused by the interaction of biological and other factors, which was "the third disease" beyond infectious and non-infectious diseases, namely, "decline disease of forest". Climate difference, improper management, unbalanced usage of soil water, and high content of N settled from air were the inducing factors, among which, climate difference and unbalanced usage of soil water were the main ones, while insect harm and shoot blight were the promoting factors.

Agriculture↗

PubMed2003

[Eco-value level classification and ecosystem management strategy of broad-leaved Korean pine forest in Changbai Mountain].

To realize the sustainable management of forest ecosystems, we should explicitly clarify the types and differences of the ecosystem services provided by different ecosystems under different conditions, with rethinking about the value of forest ecosystems; then solid management strategies and measurements will be enacted and applied to achieve the objects. The broad-leaved Korean pine forest (BLKPF) in Changbai Mountain is a unique and important forest type in China, owing to its many important ecosystem services such as preventing soil erosion, regulating climates, nutrient cycling, providing wood and non-timber forest products, etc. This paper is a preliminary study on the management strategy of BLKPF on the basis of analyzing the characters of the ecosystems and the relative importance of services they provided in this region. Based on the latest research of ecosystem services of BLKPF in Changbai Mountain, an idea of eco-value level (EVL) was introduced, and accordingly, management strategies were summarized by adopting the advanced theories in ecosystem management science and by analyzing field survey data. EVL means the relative amount of the value of ecosystem services provided by certain ecosystem, which can indicate the difference between services in given objects. The EVL classification of BLKPF implies the relative amount of the eco-value of different ecosystems including virgin forest, secondary forest, forest with human disturbance, and man-made forest in the clear-cutting sites. Analytical Hierarchical Processing method was used to formulate the equation for EVL index. Eight factors, namely, slope, soil depth, stability of soil maternal material, coverage of above-ground canopy, species diversity, regeneration rate of the stand, life span of dominant tree species, and intensity of human disturbance were chosen to build the formula. These factors belonged to three aspects affecting ecosystem services including the physical environment, community, and disturbance regime, and their selection and scaling were based on the previous studies on the BLKPF. The equation of EVL index (EI) was expressed as: EI = 0.542A1 + 0.171A2 + 0.072A3 + 0.067B1 + 0.043B2 + 0.014B3 + 0.010B4 + 0.081C1. According to the range of EI, ecosystems were classified into three types: low EVL type with EI from 1.000 to 1.874, medium EVL type with EI 1.874-2.749, and high EVL type with EI 2.749-3.623. Typical plots were surveyed and scaled with EI, and the predominant characters of each EVL type were summarized. Most forests of high EVL type were those in sites at high risk of soil erosion and hard to recover after disrupted. Forests of medium EVL type were those with worse community structure and composition, and were disturbed by human activities in relative steep sites. Forest of low EVL type were those in plane site with serious disruption or some young man-made stands. Based on the analyses of the characters of these three types, different management strategies were put forward. For high EVL type forest, strictly protection is most important to maintain the forest in natural succession and its eco-services. For medium EVL type forest, the key points of management are restoring their health and vigor by regulating their composition and structure in a seminatural way. For low EVL type forest, some area could be used to extensive exploration for economic benefits, and the rests should be reconstructed towards the original stand in composition and structure, based on the 'shadow ecosystem' in a close-to-nature way to promote the capacity of providing more eco-services.

Ecosystem↗

PubMed2003

[Optimization of spatial arrangements and patterns for shelterbelts or windbreaks].

Spatial arrangements and patterns of shelterbelts or windbreaks are the key factors influencing the shelterbelt structures, shelter benefits, and shelterbelt sustainability. In order to keep the shelter benefits and achieve the sustainability of shelterbelts, it is necessary to keep the reasonable arrangements and patterns in spatiality and the continuation in time. Based on the investigations on the shelterbelts, which were established in 1992 as the models in Shuangjingzi Township, Changtu County, Liaoning Province, and combined with the experiences and practices of shelterbelt management, the authors studied and summarized the arrangements and patterns of shelterbelts, which included the direction of a single shelterbelt and shelterbelt-networks, the arrangement of tree composition in a shelterbelt, and the mixture of tree species for shelterbelts. Additionally, the spacing intervals between shelterbelt and the spatial patterns for regional shelterbelts were also discussed. The results indicated that the direction of both single shelterbelt and shelterbelt-networks should be perpendicular to the disaster winds. It is better for the structure of a shelterbelt to arrange the trees in triangle form in a shelterbelt. According to the edge effect, the tree species which grow slowly should be arranged in the edge lines, but the tree species which grow fast should be arranged in the inner lines of the mixed shelterbelts. Optimal spacing intervals between windbreaks could be predicted from the indices of a given windbreak structure (porosity), percentage of desired wind speed reduction, and tree growth model (model for determining initial protective maturity age). The patterns of shelterbelts in large scale should be evaluated and arranged according to the principles of landscape ecology. The results mentioned above would provide the evidences for shelterbelt sustainable management.

Conservation of Natural Resources↗

PubMed2002

[Sustainable management for farmland shelterbelts].

The spatio-temporal pattern of shelterbelt regeneration is an important issue which determintes whether shelterbelt network produces protective effects sustainably. This article developed a new method of imitating "normal forest" to manage shelterbelts. Based on an administrative village as an organized management unit, each shelterbelt in the organized management unit will be individually regenerated and regulated, until the number of the shelterbelts in each age-class from young to mature ones will be equal, and the shelterbelts in each age-class will be spatially distributed uniformly in the shelterbelt network of an organized management unit. Consequently, this method might temporally ensure sustainable and stable ecological services which are provided by the shelterbelts in an organized management unit.

Agriculture↗

PubMed2002

[Assessing indices of container seedling quality].

In this paper, the assessing indices of container seedlings quality were synthesized in accordance with growth and physiological factors. The results showed that the seedling quality might be determined by the dormancy state of terminal bud, nutrient condition of plant, and the state of root system. The critical quality indices should include stem diameter at soil surface, dry weight of terminal bud, and soluble sugar content. Moreover, some indices such as root system vitality and dry weight of plant were also important.

Plant Development↗

PubMed2002

[Phase-directional management of protective plantations. II. Typical protective plantation: farmland shelterbelt].

This paper is the second part of the series reports on phase-directional management of protective plantations. Based on the fundamentals of phase-directional management for protective plantations in paper I, discussions on protective maturity, management phase, and regeneration patterns and methods for shelterbelt or windbreak were conducted. Firstly, the two points of protective maturity of Populus spp. i.e., initial protective maturity age (IPMA) and terminal protective maturity age (TPMA), were determined. According to the growth pattern of shelterbelt, the IPMA was 16 years and 24 years for local poplar and hybrid poplar shelterbelts, respectively, and TPMA was the natural age for both local and hybrid poplar shelterbelts, which was determined on the basis of change pattern of porosity. Secondly, the three management phases of shelterbelts were divided quantitatively based on the analyses of discrete degrees of diameter, IPMA and TPMA. Thirdly, the corresponding measures for phase-directional management in each phase were also developed. In pre-maturity phase, i.e., the period from establishment of shelterbelt to IPMA, the measures such as soil cultivation, irrigation, fertilization, weed clearing, intercropping and branch cutting etc. should be conducted. In maturity phase, i.e., the period from IPMA to TPMA in theory, but the period from IPMA to regeneration age in practice, the techniques of managing the shelterbelt porosity around 0.25 (the best porosity value for wind protection) should be developed. In this phase, the porosity model was constructed according to the distribution pattern of base area for the poplar shelterbelt. The classification of shelterbelt trees, i.e., 4-grade classification, was established by considering the contribution of trees to the shelterbelt structure, which can provide the standard for thinning and tending of shelterbelt. Additionally, the density controlling techniques were also discussed. In the period of regeneration, i.e., from the regeneration age to the establishment of next generation shelterbelt, the techniques of regeneration such as determination of regeneration age, arrangement of regeneration patterns should be paid great emphasis. The influences of regeneration patterns and methods on regeneration period were specially discussed, and the changes of three management phases were illustrated by different regeneration patterns in the end of this paper. These results were obtained from poplar shelterbelt, but the fundamentals could be applied in any other shelterbelts.

Agriculture↗

PubMed2002

[Phase-directional management of protective plantations. I. Fundamentals].

In order to ensure the higher effectiveness, more stability and sustainability of Protective plantations, the definition of phase-directional management (PDM) of protective plantations was brought forward on the basis of management researches and practices for protective plantations. The basics of PDM is protective maturity, which is defined as the time when the protective plantations attain to the state that the protective plantations can provide effective and complete protection to the objects needed to be protected. Protective maturity has two points, initial protective maturity age (IPMA), the age of protective maturity started, and terminal protective maturity age (TPMA), the age of protective maturity ended. Three management phases of protective plantation, i.e., prematurity phase, the period from sapling or establishment to initial protective maturity, protective maturity phase, the period of protective maturity lasting, and regeneration phase, the period during regeneration and before the establishment, are divided based on the fundamental of protective maturity. Directional management of protective plantation means that all of the management techniques in each phase are directed at the aim of protective maturity, i.e., protective maturity is the direction of management of protective forests, and protective maturity is the final objective for the management of protective forests. In order to sustain the protective maturity state, corresponding measures should be conducted in each phase, according to the classification of protective plantations. In pre-maturity phase, the purpose of managing is to accelerate the protective maturity, therefore, the measures such as weed clearing, soil cultivation, irrigation, fertilization, intercropping and branch cutting etc. should be conducted in protective plantations. In maturity phase, the aim of managing is to sustain the protective maturity, i.e., the techniques (tending and thinning) of controlling the structure of protective plantations should be paid emphases. In the period of regeneration, the objective of managing is to recover the protective maturity, accordingly, the regeneration patterns and ways should be determined reasonably. Additionally, the methods of determining protective maturity, i.e., the core of the phase-directional management, are also given corresponding to farmland shelterbelt, sand-fixation forest and water and soil conservation forest. For farmland shelterbelt, IPMA can be determined according to the growth pattern of tree height under the suitable structure (porosity). For sand-fixation forest, it can be determined by the cover degree of the forest, i.e., the age when cover degree gets to pi/4 can be considered as IPMA. In the case of water and soil conservation forest, IPMA is determined by the canopy closure at the height of 1m above forest ground, which can be obtained from the hemispherical silhouettes in vertical direction. As for the TPMA, it can be described by the natural age of trees for all of above-mentioned three kinds of protective plantations, but the concrete methods for estimating the natural age of trees in each kind of forests are different.

Agriculture↗

PubMed2002

[Early diagnosis of low-value forest: an approach of ecological factors].

The management and improvement of low-value forests is an important issue of forestry in China. This paper put forward a new thought of early diagnosis for low-value forest. By applying this method, the forest growth trend before the explosion of the state of low-value forest was diagnosed according to the formation rule of low-value forest, and so, managers could adopt corresponding management measures in time. Taking a case study of Chinese pine plantations in western Liaoning Province, the early diagnosis of low-value forest was studied, and set up early diagnosis techniques of ecological factor approach based on single-factor experiment and discriminant analysis: 1) following discriminant indices were selected: soil thickness (X1), organic matter (X2), soil nitrogen content (X3), soil water content (X4), and soil microbic quantity (X5); 2) discriminant function could be expressed as: Y = 1.596X1 - 0.51X2 - 3.196X3 + 1.622X4 + 1.898X5:3) early diagnosis of low-value forest was carried out by discriminant function and the value of each discriminant index. For early diagnosis of low-value forest, this paper is a pilot study. It is suggested that the forming mechanism of low-value forest and their related study should be strengthened.

China↗

PubMed2002

[Introduction and selection of new poplar clones in shelterbelts/windbreaks in northern Liaoning].

Six new poplar clones were introduced in Qianshuanging township of Changtu county, Liaoning Province as experiment materials, and their indeces in growth, cold resistance, disease infection, and insect infection were evaluated and compared to the locally grown Fuzha II poplar. According to the comparison of the 4 indices, the study found that N-119 poplar showed all the scores obviously better than those of CK and other poplars, and was recommended for the area. The growth of Zhonglin 95 was higher, and its disease and pest infection was equal or near to the CK. So, the poplar Zhonglin 95 is also worthy to be recommended.

Agriculture↗

PubMed2002

[Ecological forecasting: a frontier in ecology].

An evolving science of ecological forecasting is beginning to emerge, and could have an increasingly important role in policy-making and management of natural resources and environment. The progress in computer science, quantitative analysis and ecological theory, together with the application of new high technology, will increase our ability to forecast ecosystem change. The authors introduced the connotation of ecological forecasting, relevant research advances, and some typical examples. Ecological forecasting is an important frontier in ecology, and also, would be an important direction for future ecological study.

Decision Making↗