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1.
1 STRATEGY BACKGROUND1.1 Quickening of Urbanization ProcessSince the reform and opening-up in China in 1978,economic community developed rapidly. By the endof 2003, GDP has exceeded $1 000 billion. With therapid development of Chinese economy, residentialmode focusing on rural population is now changing,urbanization process is quickening, traditional cityscale is expanding into metropolis (Tianjin, Xi’an,Chengdu, Chongqing, etc.) or super cities (Beijing,Shanghai, Guangzhou, etc.…  相似文献   

2.
Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in situ sampling strategy and generally realize the contribution of environmental effects to variation in needle traits,it is still uncertain which needle traits are most influenced by genetic effects and which are most influenced by the environment.Using both a common garden experiment to eliminate environmental heterogeneity and an in situ sampling strategy,we compared 18 Pinus tabuliformis needle traits among 10 geographical populations.Using both sampling strategies,we found significant differences in needle traits among populations and among individuals within populations.Differences in the‘‘among-population’’variance component between the two sampling strategies revealed the environmental contribution among natural populations for each trait.The among-population variance in the following traits exceeded 8%:needle length,number of stomata within 2 mm(NS2),number of stomatal lines on the planar side,number of resin canals(RCN)and the resin canal area(RCA).For the stability of needle traits,NS2,RCN,RCA,ratio of the vascular bundle area to the RCA(VBA/RCA),and MA/RCA differed significantly in more than five provenance changes between the common garden populations and natural populations,which may be susceptible to environmental effects.Conversely,the crosssectional area,mesophyll area(MA),MA/(VBA+RCA),and MA/VBA were phenotypically stable.Geographic variation patterns and systematic relation of needle traits differed between the two sampling strategies,suggesting that in situ sampling results may reflect environmental effects and deviate statistical parameters for genetic study.Future studies of genetic evolution in the context of geographic variation should be based on appropriate sampling strategies and stable phenotypic traits.  相似文献   

3.
1 INTRODUCTIONConservation of natural forests is a key issue in China’ssustainable rural development. One of the problems inrural China is the use of large quantities of wood andred bricks in house construction. This causesdestruction of forests, and the consequent watershortage and soil erosion problems.With the increase in living standards in rural areas,demand for housing is growing, and so is the demandfor high quality and attractive hotels for tourists.Moreover, many schools in Chi…  相似文献   

4.
The purpose of this study was to determine a suitable model for investigating the effects of climate factors on the area burned by forest fire in the Tahe forest region, Daxing’an Mountains, in northea...  相似文献   

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Simultaneous flowering caused a gregarious dieback of umbrella bamboo (Fargesia murielae) all over the world in 1993-2000. Mountain Shennongjia in Central China‘s Hubei Province is the only native home of umbrella bamboo, where it dominates the understorey of the farges fir (Abiesfargesii) forest between 2 400 and 3 100 m, covering the ground for more than one century before a periodically flowering death. Data from 20 quadrats along a vegetation sequence revealed that the density, coverage,and height of umbrella bamboo negatively affected the species richness, diversity, and evenness of vascular plants in the forest. Local climax community of fir-bamboo was the poorest in species diversity, while the bamboo-free communities (i.e. shrubs and meadows)were bearing a higher species diversity. The simultaneous dieback of umbrella bamboo is an ecological relcase, which can pcriodically promote the plant diversity in the fir forest.  相似文献   

6.
INTRODUCTIONAccompanied with the steady economic growth andimprovement of people’s living standards in China, highquality timber structural houses are drawing moreattention. Due to the introduction of foreign modernwooden house constructing techniques, timberstructural houses have sprang up in China, especiallyin some metropolises such as Beijing and Shanghai(Figures 1 to 3). At present, there are three types oftimber structures being adopted in China, whichincludes sawn and round timb…  相似文献   

7.
Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ’Gold Mound’ and Spiraea × bumalda ’Gold Flame’. The present study aimed at exploring the antioxidant capacity in roots of spiraeas and revealing their adaptability to salt-alkali stress. Results indicate that the oxygen free radicals contents, electrolyte leakage rates and MDA contents in roots of Spiraea × bumalda ’Gold Mound’ and Spiraea × bumalda ’Gold Flame’ show an increasing tendency with the increases of the salinity and pH value, whereas the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) all increased firstly and then decreased. With the increase in intensity of salt-alkali stress, the CAT activity in roots of Spiraea × bumalda ’Gold Flame’ is higher and the increasing extents in the oxygen free radicals contents, electrolyte leakage rates as well as MDA contents are lower compared with Spiraea × bumalda ’Gold Mound’, indicating that Spiraea × bumalda ’Gold Flame’ has a stronger antioxidant capacity.  相似文献   

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9.
Underground fires are slow spreading, long-lasting and low temperature smoldering combustion without flames, mainly occurring in peatlands and wetlands with rich organic matter. The spread of the smoldering is maintained by heat released during combustion and monitoring this is an important approach to detect underground fires. The Daxing’an Mountains region is a hotspot for underground fires in northeast China. This study examined a L arix gmelinii plantation in the Tatou wetlands of the Daxing...  相似文献   

10.
Siberian Pine (Pinus sibirica) is an ecologically and eco-nomically important species in pristine forests throughout northern Rus-sia. Four provenances of P. sibirica were introduced from Mongolia and Russia to the Greater Xing’an Range (the Daxing’anling), northeast China in 1993. The aim of this research was to study genetic variation and selection of the introduced four Pinus sibirica provenances. Heights (H), basal diameters (BD), survival rates (SR) and crown lengths (CL) of different families were measured as primary outcomes in different growth years. Results of data analyses demonstrated high coefficients of phenotypic variation (PCV) and heritability (H2) for H, BD and CL at 18 years after introduction. PCV and H2 increased with age. Correlations of growth traits between any two growth years were all significantly positive, but the correlation coefficient was smaller when the growth year interval was larger. Correlations between H and the original environment factors decreased gradually, indicating that with long-term subsistence in the new environment, the influence of the source environment declined. Colligation of multiple traits to estimate provenances showed that Novosibirsk, Tomsk, and Altai Mountains had higher survival rates and biomass, and proved more suitable for introduction and plantation in the Greater Xing’an Range in China.  相似文献   

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Taking the communities of the sample sites in Aershan of Inner Mongolia as an investigation object, the indices affecting plant diversity were studied. The investigation was carried out in three different forest types (natural forests, plantations and regenerated forests after fire). Results show that 95 plant species belonging to 19 families and 50 genera were identified in total. Of these species, nine were arbors, six were shrubs and the other 80 were herbs. We found some differences in the dominant species of different layers in three forest types. Natural forests had the largest importance value for the total number of species, followed by plantations and regenerated forests after fire. Plantations and natural forests had a similar change in richness indices. The largest value of richness indices was obtained in natural forests, while the lowest value was in regenerated forests after fire. Three diversity indices (Simpson’s, Shannon-Wiener and Pielou’s indices) indicate a similar trend in all sample plots. With an increase in elevation, values of diversity indices first increased and then decreased. In different forest types, similarity between natural forests was largest, while similarity between the regenerated forests and plantations was lowest.  相似文献   

13.
The establishment of China’s forestry science and technology evaluation system is an important guarantee measure to improve the level of forestry science and technology management and promote forestry science and technology advancement. Based on the analysis of the current condition of forestry science and technology evaluation in China, the paper presents the suggestions to establish and improve forestry science and technology system, including the change in evaluation subject, the standardization of evalu...  相似文献   

14.
A model stand of near-natural forest with an area of 3 000 m^2 was established as a case study in Pudong New District, Shanghai City in 2000. Eleven species were planted in model stand. As the dominant species of community, 4 evergreen broad-leaved tree species, namely: Machilus thunbergii, Cyclobalanopsis glauca, C.mylsinafolia and Castanopsis sclerophylla were chosen, accompanying with evergreen broadleaved shrub species like Pittosporum tobira, Ligustrum quihoui and Dis~‘lium racemosum, etc. as well as deciduous tree species, Liquidambarformosana, etc. After three-year growth, the community physiognomy had changed to be a shrub stage, and the highest tree reached to 4.6 m. A forest physiognomy would be formed in about 10 years estimated. The method of construction of near-natural forest that had been worldwidely applied would also play a key role in the construction of urban forest in China.  相似文献   

15.
As one of the four civilizations, China is enriched with brilliant traditions and cultures. The crane culture is a unique ?ower in this garden of cultures. Over thousands of years, crane has been featured in numerous graceful and tasty artistic images and…  相似文献   

16.
Management of the understory land is an economic form to develop cultivation and breeding in making use of the forest ecological environment.It is also an important means to increase the income of forest farmers in the forestry regions after the reform of forestry real rights.This paper investigated the management status of understory land,and analyzed the impacts and destruction of its improper management upon the forest ecology environment.The management right of the understory land is a restricted right of property,because the management is related to the ecology protection of forest and woodland.In addition to private property rights,it should also comply with the arrangement of national forest management.Therefore,while encouraging and developing the understory land management,it’s important to establish a legal system for executing the management rights,and the management of the understory land should be included in the scope of the forestry management.  相似文献   

17.
Although most Sinojackia species are endangered, they contribute greatly to the biodiversity of local ecosystems. Sinojackia microcarpa, an endangered species, is distributed only in three provinces of eastern China. Determining the genetic diversity of S. microcarpa provides key information for germplasm evaluation and species conservation. Here we used simple sequence repeat (SSR) markers to investigate the genetic diversity of eight natural populations of S. microcarpa. Leaf samples were collected from 144 individuals in 8 wild populations. The 156 bands were generated from 14 pairs of informative SSR primers, with an average percentage of polymorphic bands of 45.67%. The average values of Nei’s genetic diversity (He) and Shannon’s diversity index (I) were 0.1007 and 0.1658, respectively. The total genetic variation of S. microcarpa existed mainly within the eight populations, rather than among populations, and reached 86.41%. A cluster analysis showed that the eight wild populations of S. microcarpa could be classified into four groups, at a threshold of 4.0, based on an analysis of the SSR genotypes. Furthermore, there was a significant association between the phylogenetic relationships and the geographic locations of the S. microcarpa populations. In particular, populations from Fuyang, Jiande, and Lin’an in Zhejiang Province had close phylogenetic relationships and geographic distances. In addition, these three populations had the highest genetic diversity and the most individuals, suggesting that these three locations may be the S.microcarpa distribution center. This study serves as a model for studying the genetic diversity of endangered plant species.  相似文献   

18.
Whitebark pine (Pinus albicaulis) populations are in decline across the species’ range due to historic wildfire exclusion, mountain pine beetle (Dendroctonus ponderosae, MPB) outbreaks, and an invasive...  相似文献   

19.
News and Events     
Danjiangkou City of Hubei Provincebegan to implement participatory povertyrelief in 30 key poor villages since 2002,Dujiawan Village of Tuguanya Townshipbecame the first participatory poverty reliefpilot village of the city.Immediately after thespring festival,the staff of city’s povertyrelief office came to the village,and gottogether with household representativesunder an ancient tree,discussing the existingdifficulties and the approaches of poverty  相似文献   

20.
In China, Pinus pumila is mainly distributed in Daxing’anling, while those growing in the eastern Daxing’anling are primarily covered under the jurisdiction of Huzhong Forest Bureau. P. pumila is an evergreen shrub, 3-6 m high, and always grows vigorously. Its trunks creep along the ground, usually 10 m long or more. It is easily flammable because of the large amounts of resins and volatile oils in its body. Attacking forest fires is a dangerous work, especially in P. pumila scrubs. The fires in P. pumila scrubs are very different from those in other forest types, e.g. fierce combustion and heavy smoke. In this paper, the distribution characteristics of P. pumila scrubs were presented. Attacking techniques and safety precautions for attacking fires in P. pumila scrubs were also discussed.  相似文献   

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