洛邑“土中”与阳城“地中”辨析

洛邑为周人灭商后营建的新都,“土中”是洛邑所在之地的专称,它是对西周初年洛阳地区地理位置以及政治、经济、军事、宗教地位的概括。《周礼》中的“地中”之说源自战国时代,“地中”是在洛邑“土中”,“周辟家”影差原理、天地测量理论以及战国时期“王者需在天下之中建都”理论共同影响下的一种构想。《周礼》“地中”本属假想,不确指某地,东汉《周礼》开始流传,由于多数学者尊信《周礼》为周公所著,因此认为《周礼》中的“地中”就是西周初年营建的洛邑。郑众首倡阳城为“地中”,后经郑玄的引用、贾公彦的发挥,使得洛邑“土中”和阳城“地中”两说混杂到了一起,遂有了阳城是西周初年周公营建洛邑时,测影寻找到的“地中”之说。

Future China-Africa research collaboration in geoscience:Challenges and opportunities

At the 19th G20 Summit in Brazil in November 2024,China promoted the development of sustainable solutions to climate change,biodiversity loss,and environmental pollution.This continued the theme of the 2016 G20 Hangzhou Summit,at which China placed development at the center of the G20’s macroeconomic policy coordination for the first time,adopting the G20 Action Plan on the United Nations 2030 Agenda for Sustainable Development and the G20 Initiative on Supporting Industrialization in Africa and Least Developed Countries.In Brazil,China announced actions on advancing modernization in Africa over the next three years with a Chinese commitment of RMB360 billion yuan in financial support.In this article,we examine the potential role of geoscience research and practice in development,particularly in the sustainable use of natural resources,the prevention of climate change impacts,as well as mitigation of geo-hazards and their health implications,indicating the areas where China’s geoscience for Africa is strong and where it requires more effort.We find that although China is the world’s leading publisher of scientific papers,its contribution to geoscience in Africa(the globe’s fastest-growing economic area),as shown by bibliometric research,appears to be rather small and inconsistent with the research priorities of Africa.Amongst the priorities for geoscience research in Africa,which are not addressed substantially by the research conducted so far,are sustainable mineral and hydrocarbon development,hydrology and hydrogeology,climate change and resilience,natural hazards,medical geology,agrominerals,and geoscience education and training.A particular opportunity for African nations is the presence of critical minerals-minerals needed for the energy transition and for batteries for electric cars in particular.Africa is well-endowed with many of these critical materials,such as rare earth elements and platinum group metals.Several research groups stress the need for the agency on the part of African institutions to map out these valuable resources,understand their value and the economics and sustainability of their extraction,encourage local business,attract investment,and scrutinize proposals from potential international investors to get the best deals.A strong point of existing China-led geoscience development includes the Deep-time Digital Earth(DDE)program online computing platform and its artificial intelligence tool GeoGPT,which is being developed in partnership with Zhejiang Laboratory.These are being developed with strong China funding support for free and wide global access,with a particular focus on Africa.These advanced tools will help to place the agency of development squarely in the hands of African scientists and institutions.In summary,the following are recommended:(1)a more coordinated and strategic approach to China-led geoscience research in Africa;(2)an Africa-centered,geoscience funding initiative that concentrates on relevant topics to the continent such as critical minerals exploration and other geological resources,materials and processes and their health implications on the populations and ecosystems in general,as well as climate change and climate change resilience;and(3)continued support for China-led international initiatives that seek to increase the agency and capacity of Africa geoscience researchers,for example the Deep-time Digital Earth platform.

A Comparative Study of the L2 Pragmatic Competence of University Students in Hong Kong and the Chinese Mainland:The Contributions of Sociocultural Context and Linguistic Proficiency

This study investigates the differences in pragmatic competence between Hong Kong and Chinese mainland university students.Participants included 19 native speakers of English,115 Chinese mainland students,divided into those who had spent time abroad in an English-speaking country(CM A)and those who had not(CM NA),and 97 Hong Kong students,divided into those from an English-medium secondary school(Hong Kong EMI)and those from a Chinese-medium school(Hong Kong CMI).Linguistic proficiency was measured by a C-test,and pragmatic competence by a Metapragmatic Knowledge Test,an Irony Test and a Monologic Role Play.Group scores were compared using ANCOVAs to control for differences in proficiency.The results point to a continuum of pragmatic competence—EMI>CMI>CM A>CM NA—reflecting the groups’access to English in real-life contexts.The differences between the Hong Kong groups and the Chinese mainland groups were clearest in those tests measuring processing capacity(i.e.,Irony Response Time and the Monologic Role Play).CM A,but not CM NA,performed as well as the Hong Kong groups on measures of metapragmatic awareness.The results are discussed in terms of Bialystok’s(1993)distinction between analyzed representation and control of processing.

Clarifying the relationship between PM2.5 and ozone complex pollution and synoptic patterns in a typical petrochemical city in the Bohai Rim region of China:Implications for air pollution forecasting and control

Meteorological conditions are vital to PM_(2.5)and ozone(O_(3))complex pollution.Herein,the T-mode principal com-ponent analysis method was employed to objectively classify the 925-hPa geopotential height field of Dongying from 2017 to 2022.Synoptic patterns associated with four pollution types-namely,PM_(2.5)-only pollution,O_(3)-only pollution,Co-occurring of PM_(2.5)and O_(3)pollution,Non-occurring of PM_(2.5)and O_(3)pollution-were characterized at different time scales.The results indicated that synoptic classes conducive to PM_(2.5)-only pollution were“high-pressure top front”,“offshore high-pressure rear”,and“high-pressure inside”,while those conducive to O_(3)-only pollution were“offshore high-pressure rear”,“subtropical high”,and“high and low systems”.The Co-occurring of PM_(2.5)and O_(3)pollution were influenced by high pressure,and the Non-occurring of PM_(2.5)and O_(3)pollution were linked to precipitation and strong northerly winds.The variation in dominant synoptic patterns is crucial in the frequency changes of the four pollution types,which was further validated through the analysis of typical cases.Under the favorable meteorological conditions of high-pressure control with strong northerly winds or a subtropical high and inverted trough both with strong precipitation,there is potential to achieve coordinated control of PM_(2.5)and O_(3)in Dongying.Additionally,measures like artificially manipulating local humidity could be adopted to alleviate pollution levels.This study reveals the importance of comprehending the meteorological factors contributing to the formation of PM_(2.5)and O_(3)complex pollution for the improvement of urban air quality in the Bohai Rim region of China when emissions are high and the concentration of air pollutants exhibits high meteorological sensitivity.

Assessing the range of blasting-induced cracks in the surrounding rock of deeply buried tunnels based on the unified strength theory

Blasting-induced cracks in the rock surrounding deeply buried tunnels can result in water gushing and rock mass collapse,posing significant safety risks.However,previous theoretical studies on the range of blasting-induced cracks often ignore the impact of the in-situ stress,especially that of the intermediate principal stress.The particle displacement−crack radius relationship was established in this paper by utilizing the blasthole cavity expansion equation,and theoretical analytical formulas of the stress−displacement relationship and the crack radius were derived with unified strength theory to accurately assess the range of cracks in deep surrounding rock under a blasting load.Parameter analysis showed that the crushing zone size was positively correlated with in-situ stress,intermediate principal stress,and detonation pressure,whereas negatively correlated with Poisson ratio and decoupling coefficient.The dilatancy angle-crushing zone size relationship exhibited nonmonotonic behavior.The relationships in the crushing zone and the fracture zone exhibited opposite trends under the influence of only in-situ stress or intermediate principal stress.As the in-situ stress increased from 0 to 70 MPa,the rate of change in the crack range and the attenuation rate of the peak vibration velocity gradually slowed.

Research on pumped storage and complementary energy development models for abandoned mines in China

Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines.

Heterogeneity in Soil Seed Banks in a Mediterranean Coastal Sand Dune

Characteristics of total soil seed banks and permanent soil seed banks in three microhabitats in a Mediterranean coastal sand dune were investigated by using natural germination method combined with physically scanning separation method. The composition and structure of soil seed banks were analyzed between the microhabitats by using functional group method. The distribution patterns of soil seed bank were also analyzed between the microhabitats. We also analyzed the relationship between seed size and seed persistence in soil. The results show greatly spatial heterogeneity existed in soil seed bank of the Mediterranean coastal sand dune, even in the same microhabitats seed distribution was uneven. Sometimes a great difference occurred between them. Microhabitats significantly affected the distribution patterns of total soil seed banks and seed banks of the functional groups. The open area generally had the greater densities of seeds, but the seed densities under shrub and in trail were lower than that in the open area. Legumes seeds accounted for 76.0% total persistent seed banks. Annual and perennial grasses produced transient seed banks as no seeds were retrieved from the sieved soils. Seed persistence of legumes, umbeliferaes, perennial forbs, compositaes, annual forbs, crucifer decreased gradually. They were 50.1%, 45.6%, 40.6%, 6.3%, 5.6% and 0.6% respectively in the soil. There was a positive relationship between seed size and seed persistence. Bigger seeds had higher persistence, and vice versa.

Vegetation Changes and Human Influences on Qian’an Basin Since the Middle Holocene

Vegetation changes and human influences on natural environments since 5 000 a BP were discussed based on the pollen data supported by radiocarbon dating from Cangumiao and Yujiawa profiles in Qian'an Basin, the southern area of Yanshan Mountain. The research indicates that (1) from 4 600 to 3 100 a BP, deciduous broad_leaved forests dominated by Quercus grew in the Basin, (2) after 3 100 a BP, broad_leaved species reduced and Pinus increased, in response to the cooling climate, (3) since 1 600 a BP, forests had been destroyed seriously due to the increase of agricultural activities, and (4) pollen analysis showed that Castanea trees had been cultivated for 1 600 years, and Oryza had been planted for 700 years in Qian'an Basin.

Fluorine Content in Soil and Groundwater of Songnen Plain in Northeast China

[Objective] This study aimed to investigate the fluorosis content in the groundwater of Songnen Plain and provide a theoretical basis for the prevention and control of endemic fluorosis in Songnen Plain. [Method] The relationship of drinking water type endemic fluorosis with the fluoride content in the soil and groundwater of Songnen Plain was analyzed. [Result] The endemic disease in this region is concentrated in the Song-Liao Plain and Hulunbuir Plateau on both sides of the Daxinganling Mountain. Severe and medium disease areas are distributed mainly in alluviallacustrine plains with dense depressions of lakes and marshes. The strata are commonly fine-grained loess and mucky soil. The groundwater is dominated by HCO3-Ca·Na and HCO3·Cl-Na·Ca types, with fluorine content of 1.80-16.00 mg/L, generally 4-6 mg/L. Light disease and non-disease areas are distributed in the alluvial-lacustrine plains with less or without depressions of lakes and marshes. The strata are mainly coarse-grained silty soil and sandy soil. The chemical types of ground water are Cl-Ca·Na and HCO 3 Cl-Na·Ca. The content of fluorine in ground water is commonly lower than 2 mg/L. [Conclusion] High fluorine groundwater formation is closely related to the geological environment.

Relation between Economic Development Level and Resource and Environment Carrying Capacity of Central Area of Yunnan Province Based on Decoupling Analysis

Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling degree and temporal changes of economic development level and resource and environment carrying ca- pacity in the central area of Yunnan Province. Results indicated that （i） the economic development level and resource and environment carrying capacity in the central area of Yunnan Province mainly experienced strong decoupling, weak decoupling, and ex- pansive negative coupling, and in general it was strong decoupling, and it took on re- verse ＂N＂ in temporal changes. （ii） Change rate of economic development level in the central area of Yunnan Province was greater than zero, but the amplitude of change was not large, while the change rate of resource and environment carrying capacity was negative in 2007-2008, and it was positive in the rest years; from 2007, it took on gradual expansion trend, and scissors difference gradually increased after experi- encing reverse ＂V＂ change. （iii） The strong decoupling was the main situation and it reached the peak value in T5 period and T6 pedod.

Characterization of Genetic Polymorphism of Novel MHC B-LBⅡ Alleles in Chinese Indigenous Chickens

Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations. To reveal the genetic variation of the B-LB Ⅱ gene, 37 types of patterns detected by PCR-SSCP were investigated first, which would be used to screen novel B-LB Ⅱsequences within the breeds. The types of PCR-SSCP patterns and final sequencing allowed for the identification of 31 novel MHC B-LBⅡ alleles from 30 unrelated individuals of Chinese chickens that were sampled. These are the first designators for the alleles of chicken MHC B-LBⅡ gene based on the rule of assignment for novel mammalian alleles. Sequence alignment of the 31 B-LB Ⅱ alleles revealed a total of 68 variable sites in the fragment of exon 2, of which 51 parsimony informative and 17 singleton variable sites were observed. Among the polymorphic sites, the nucleotide substitutions in the first and second positions of the codons accounted for 36.76% and 35.29%, respectively. The sequence similarities between the alleles were estimated to be 90.6%-99.5%. The relative frequencies of synonymous and nonsynonymous nucleotide substitutions within the region were 2.92%±0.94% and 14.64%±2.67%, respectively. These results indicated that the genetic variation within exon 2 appeared to have largely arisen by gene recombination and balancing selection. Alignment of the deduced amino acid sequences of the β1 domain coded by exon 2 revealed 6 synonymous mutations and 27 nonsynonymous substitutions at the 33 disparate sites. In particular, the nonsynonymous substitutions at the putative peptide-binding sites are considered to be associated with immunological specificity of MHC B-LB Ⅱ molecule in Chinese native chickens. These results can provide a molecular biological basis for the study of disease resistance in chicken breeding.

Variation of Nitrogen Uptake and Utilization Efficiency of Mid-Season Hybrid Rice at Different Ecological Sites under Different Nitrogen Application Levels

[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.

The runoff characteristics and harmonic analysis of the soil moisture dynamics in Robinia pseudoacacia stand

Robinia pseudoacacia stands act as a typical ecological protection forest in hilly semi-arid area of China. Two fields of surface runoff were separately set up in R. pseudoacacia stand and its clearcut area in the western Liaoning Province (1850-12225 E, 4024-4234 N) for measuring the characteristics of runoff and sediment as well as soil moisture dynamics. Contractive analysis of the two land types showed that there existed a significant difference in volumes of runoff and sediment between the sites of R. pseudoacacia stand and its clearcut area. The runoff volume and sediment volume in clearcut area were much bigger than those in R. pseudoacacia stand, with an increase amount of 40%-177% for runoff and 180%-400% for sediment. Hydrograph of surface runoff of typical rainfall showed that the peak value of runoff in R. pseudoacacia stand was decreased by 1.0-2.5?0-3m3s-1 compared with that in its clearcut area, and the occurring time of peak value of runoff in R. pseudoacacia stand was 10-20 min later than that in its clearcut area. Harmonic analysis of soil moisture dynamics indicated that the soil moisture in R. pseudoacacia stand was 2.3 % higher than that in clearcut area, and the soil moisture both in R. pseudoacacia stand and its clearcut area could be divided into dry season and humid season and varied periodically with annual rainfall precipitation. It was concluded that R. pseudoacacia stand plays a very important role in storing water, increasing soil moisture, and reducing surface runoff and soil erosion.

The Gaoyuzhuang Palaeobiology

Black bedded, nodular, and lenticular chert and silicified parts of stromatolites from the approximately 1 400 - 1 600 million year-old Gaoyuzhuang Formation, North China, contain remark-ably well prep served microflora composed of diverse prokaryotic and possible eukaryotic microbes. Macroscopic algae have also been found. This Formation provides important paleobiological information from which to assess status of Mesoproterozoic life, and to evaluate paleoenvironmental conditions and pre-Phanerozoic biostratigraphy. The Gaoyuzhuang Formation has yielded over 100 taxa described by over 10 investigators. Most of the microbial taxa can be divided into three different assemblages according to their paleobiological and paleoenvironmental characteristics. I. The oscillatoriacean/chroococcacean assemblage which occurs in the first member of the Formation and this is interpreted to represent an assemblage from shallow water mat-building and mat-dwelling taxa with some possible planktonic taxa; 2. the nostocacean assemblage found only in the second member, and includes benthic mat-building or mat-dwelling taxa; and 3. the chroococcacean assemblage of the fourth member, which represents intertidal to supratidal mat-building and allochthonous taxa. Proterozoic microfossils found in chert, especially cyanobacteria, are possibly more valuable as paleoenvironmental indicators than as chronostratigraphic tools because of their morphological conservation, although trends in diversity appear to exist for cyanobacteria in the Proterozoic. The general characteristics of Gaoyuzhuang microfossils, and the fact that most nostocacean chains occur and are. preserved with the chain perpendicular to bedding indicate that: (1) the individual size of Gaoyuzhuang microfossils are part of a general trend of increase with time; (2) Gaoyuzhuang deposits are possibly in a fresh water environment and the rate of sedimentation might be equal to or less than the microbial growth rate; (3) the sedimentary model of Gaoyuzhuang might be from intertidal to subtidal or deep sea, and then to intertidal or supratidal; and (4) the eukaryotic organisms had densely occurred when Gaoyuzhuang Formation deposited.

Effects of Fertilization on Growth and Soil of Middle-aged Slash Pine Forest

In order to promote the growth of mid-aged Pinus elliottii plantation, the effects of different fertilizing amounts of formula fertilizer were studied on the growth, the soil and cost-benefit of 9 year-old Pinus el/iottii plantations in the north- ern part of Hunan, China. Three years after fertilization, the results showed that the increments of DBH, height, individual volume and stock volume of stand, and the fertilizer benefit of the different fertilization treatments were higher than the control to varying degrees, and among them, 700 g/tree was the best for promoting the growth of Pinus elliottii. Two years fertilization, the soil nutrients were improved compared with before, pH values of different layers decreased, organic matter and rapid available K contents increased, and rapid available N content increased dra- matically with the upper layer having an increase higher than the lower one; rapid available P decreased at different levels with the upper layer having a decrease lower than the lower one; and proper application of fertilizer could promote the growth of Pisolithus tinctofius, and 7 months after fertilization, the number of Pisolithus fruiting body generally increased with the increase of the fertilizer within 100-800 g/tree. The yield and benefit per unit area could be increased by fertiliza- tion for 1 time in middle-aged Pinus elliottii plantations, and the best fertilizing amount was N-P-K fertilizer 700 g/tree.

The ridgelet transform with non-linear threshold for seismic noise attenuation in marine carbonates

Wavelet transforms have been successfully used in seismic data processing with their ability for local time - frequency analysis. However, identification of directionality is limited because wavelet transform coefficients reveal only three spatial orientations. Whereas the ridgelet transform has a superior capability for direction detection and the ability to process signals with linearly changing characteristics. In this paper, we present the issue of low signal-to-noise ratio （SNR） seismic data processing based on the ridgelet transform. Actual seismic data with low SNR from south China has been processed using ridgelet transforms to improve the SNR and the continuity of seismic events. The results show that the ridgelet transform is better than the wavelet transform for these tasks.

Assessment of Climate for Agricultural Suitability and Optimal Allocation of Agricultural Production in the Guanzhong Region, Shaanxi Province

Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method. Three coefficients, in- cluding the resource coefficient （Cr）, the efficiency coefficient （Ce）, and the utility co- efficient （K）, were used in the models, which were calculated based on temperature, moisture, and sunshine duration data of Guanzhong region, Shaanxi Province. The results indicated that resource coefficient was higher in west of the region than that in east, and higher in south （especially in the Central Shaanxi Plain） than that in the Weibei plateau. The value of Cr changed from 6.5 to 9.2 from north to plain area. Spatial change of efficiency coefficient was obvious, lower in the northeast than in the central plain, and the value of Ce changed from 2.3 to 6.5 from the northeast to the central plain. As for utility coefficient, it was lower in northeastern part of the Weibei plateau and in southern mountain areas than that in the central plain, showing significant latitudinal zonality. Furthermore, the value of K increased from 0.35 to 0.78 from northeast to the central plain, and decreased from 0.78 to 0.53 from the central plain to southern mountain areas. These indicated that climate resource in the central plain region was more abundant and potential, compared with other regions. GuanZhong region was classified into three larger agricultural zones and three small independent zones, according to agro-ecological assessment. Light, heat and water resources should be made use of in an efficient way in spatial allo- cation of agricultural production. For example, water facilities should also be im- proved in Weibei plateau region where highly-qualified fruit should be enhanced and fruit processing industrial chain should be shaped. Large-scale production area of wheat should be increased in central irrigation region and more vegetable bases should be developed around large and medium-scale cities. Thanks for outstanding water conservation function, the three-dimensional agriculture including medicine and other sideline production should be developed in Qinling Mountains and the special- ized commercial agriculture should be accelerated in independent small zones, ac- cording to local conditions. In the research, different crop varieties were developed in corresponding regions as per current eco-climatic conditions.

Analysis of organic acids in selected forest litters of Northeast China

Larch (Larix olgensis), Manchurian ash (Fraxinus mandshurica), Korean pine (Pinus koraiensis) and White birch (Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were collected from the stands of the above 4 species in Laoyeling and Jianlagou experiment stations of Maorshan Exp. Forest Farm (45?2-45?0N, 127?0-127?8E), Northeast Forestry University, in early October 2002. Quantitative analysis and qualitative analysis were carried out on the organic acids existing in freshly fallen litters (L layer) and hemi-decomposed litters (F layer) of the four forest species by using Gas Chromatogram system. A wide variety of organic acids were identified, including oxalic, malonic, fumaric, succinic, maleic, malic, citric, C16:0, C18:0, C18:1, C18:2, C18:3 and C20:0 acids. In respect of L litters of all samples, the oxalic acid content (over 30 mg/g) was the highest of the seven low-molecular-weight organic acids identified, while the content of oleic or linoleic (above 40 mg/g) was found to be highest among the six high aliphatic acids identified. As to F litters, oxalic acid content was also the highest, followed by linoleic and oleic. For the same tree species or the same forest, the kinds and contents of organic acids in L litters were more abundant than that in F litters.

Research on the extension of Tamarix shrubs resulted from devel-opment projects in arid area

Tamarix plant is widely distributed in the arid areas of China for its great tolerance of draught, salt and alkali and attracts more attention by its strong capacity in windbreak and sand-fixations. “Tamarix dunes” constitute special desert bio-landscape in arid area. During last several decades,Tamarix shrubs declined and “Tamarix dunes” were also severely destroyed due to the land exploitation and serious deforestation, etc. From the 1980s until now, the extending phenomenon ofTamarix shrubs caused by developmental projects such as building highway, railway was studied in the western dry area of China, including western section of Hexi Corridor of Gansu, railroads and highways around the two greatest basin in Xinjiang and interior regions in Gurbantonggut desert, through on-the-spot survey along the transportation lines and setting up sampling plots along the roads. It was found that large quantities ofTamarix plants grow in the catchment area of low-lying lands that were formed by bulldozer operation during road building period. The extension ofTamarix shrubs caused by engineering was similar to that of the other section of the area to some extent, but went beyond the original distribution. This extension is beneficial to the ecological restoration and re-vegetation of western region of China and plays an important role in control of the sandstorms and improvement of ecological environments. As a result, it is necessary to make a further study on the extending phenomenon ofTamarix shrubs and to seek approach to promote wider extension ofTamarix shrubs in suitable habitats. Key words Arid area - Tamarix - Development engineering - Vegetation extension CLC number S718.541 Document code A Article ID 1007-662X(2004)01-0045-04 Foundation Item: This study is supported by key projects of National Natural Science Foundation (39730100), National Foundation (30070640) and part of Project 973(G19990435).Biography: Huang Pei-You (1936-), Male, Professor in College of Life Science and Technology, Xinjiang University, Urumqi, 830046Responsible editor: Chai Ruihai

Ecogeographical characteristics of forest soil animal in mountainous districts of the eastern China

In this paper ecogeographical characteristics of forest soil animal i n mountainous districts of the eastern China was analyzed, and results show that soil fauna was very rich in diversified forest habitat, moreover, as times and spaces varied, their compositions and abundance changed obviously too. Forest so il animal decreased gradually in taxa and individual number from the tropics to cold-temperature zone, and they are higher in zonal forest habitat than in other ones on the same mountain. Forest soil animal also got gradually less with incr easing of depth in soil layer, and distributed principally in surface layer. The activities of human had strong affection on faunal composition and diversity of soil animal. On the tropics and subtropics mountains, forest soil animal are le ss in spring-summer than in autumn-winter, whereas they are more in summer-autum n than in winter-spring from warm-temperate zone to cold-temperate zone.