Author:

Ling Yuquan (Institute of Desert Research, Academia Sinica, Lanzhou)

Title:

Climatic characteristics and trends in the Taklimakan Desert

Publisher:

Journal of Desert Research. 10(2)

Date:

1990

Classification:

2B, 2Cb, 3D, 4Aa

Region:

Xinjiang, China

Language:

Chinese

Summary:

The climate of the Taklimakan Desert is a complex of basin and desert climates and extreme dry continental climate. It is characterized by violent change between cold and heat, minimal but concentrated and highly variable precipitation, frequent winds and severe sandstorms. There has been a trend toward a drier and warmer climate on the southern edge of the desert over the last 200 years. From 1785 to 1986, the average growth temperature for Popular Diversifolia was 19.66°C. From 1960 to 1980, however, the average growth temperature was 20.71 °C, an increase of 1.05 °C. This signifies a trend towards a warmer climate. The curve also indicates that despite small fluctuations, temperature was on the rise. Four periods can be defined: 1785-1848 with growth temperature below average value by 1 °C in 1820; 1848-1907 with a temperature-rising period with the greatest increase of 0.9 °C; 1907-1939 with a drop in temperature having a maximum value of 1.5°C. Although this rise in temperature has been slowing down, no drop is expected in the next 30 to 40 years. In 75 years from 1790 to 1846, there was abundant rain, i.e. double the average value of 50 mm. During the succeeding 20 years from 1864 to 1883, precipitation levelled. From 1883 to present, it has been at below average levels. The last thirty years have witnessed a decrease in precipitation, 13.59 mm less on the average than in the past. The curve of annual runoff from the Keriya River points to similar conclusions. During 142 years, from 1734 to 1875, annual runoff averages ran above or close to the historical average. From 1875 onwards it has fallen under the average.

Authors:

Liu Jianwei, Liu Yarong and Wang Shiji

Title:

Relationship between net photosynthesis and drought tolerance in six poplar clones

Publisher:

Scientia Silvae Sinicae. 30(1):83-87

Date:

1994

Classification:

2Ec, 6Ea

Language:

Chinese

Summary:

In order to test drought tolerance, six poplar clones were treated with PEG (mW 6 000) solution at three osmotic potential levels (-0.4 MPa, -1.0 MPa, -1.6 MPa), and their net photosynthesis rates (Pn) studied in growth culture chambers. The results show that under -1.6 MPa stress Populus simonii, P. poplaris 36 and 44 kept greater photosynthesis product accumulation until the second day. P. nigra, P. eramericane 25/86 and 28/86 decreased consumption levels from the first day. Pn decline under -1.0 MPa stress showed the same trend. Based on the significant difference in Pn of different clones under medium and severe water stress, the concept of water potential compensation point of net photosynthesis rate (Pn = 0) was developed to evaluate drought tolerance. Thus, the six poplar clones can be divided into two types: in the former group the water potential compensation point appears later; the group has a higher ability to tolerate drought. The latter group has a lower drought tolerance since the water potential compensation point appears earlier. This is important for early identification and selection of genetic variation in drought tolerance for poplar clones.

Authors:

Liu Shuhua (Department of Geophysics, Peking University, 100871)

Title:

Observation research on heat balance of artificial vegetation and bare sand dunes in Shapotou area

Publisher:

Meteorological Monthly. 20(1):9-12

Date:

1994

Language:

Chinese

Classification:

2B, 2Ed, 3Aa, 6Ed

Region:

Northwest China

Summary:

The heat balance character of artificial vegetation on sand dunes in Shapotou region were calculated and analysed. The results show that: (1) 70 percent of net radiation is dispersed as latent flux; 15 percent' as sensible heat flux; and 15 percent is stored in soil on the sand dunes with vegetation. (2) Sixty percent of net radiation is dispersed as latent heat flux; 15 percent, as sensible heat flux; and 25 percent is stored in soil on bare sand dunes. (3) Water vapour content is higher than in other dry areas of Shapotou region;

Authors:

Liu Tinghong and Wang Li (Experimental Station for Soil and Water Conservation of Linfen Prefecture in Shanxi Province)

Title:

Discussion of tillage techniques for storing water and conserving soil in arid plains

Publisher:

Bulletin of Soil and Water Conservation. 12(6):64-70

Date:

1992

Language:

Chinese

Classification:

2Eb

Summary:

Location observations of soil moisture at layers varying from zero to 200 cm in depth were made. Soil moisture dynamics during the year in arid plains can be divided into four periods, i. e. intensive consuming period in the late spring and early summer, resuming and replenishing period during the rainfall season, slow consuming period in late autumn and a relatively stable period in winter and early spring. The vertical distribution of soil moisture can be divided into three sections, i.e. quickly changing layer (0-20 cm), brisling layer (20-100 cm) and relative stable layer (100-200 cm). On the basis of these results, tillage techniques for storing water and conserving soil in arid plains were studied. In arid plains, inter-cropping of sunflower and soybean in belt shapes produces remarkable benefits for soil and water conservation and the economy. Popularizing these techniques will result in savings on manure, improved utilization of manure and increased yield.

Authors:

Liu Xinmin, Huang Xuewen et al. Yan Zhezhu (Institute of Desert Research, Chinese Academy of Sciences, Lanzhou, 73000)

Title:

Anti-desertification strategy and ecological model of a water-saving rice plantation on sandy soil in the inter-lacing agropastoral region

Publisher:

Journal of Desert Research. 15 (spc.1)

Date:

1995

Language:

Chinese

Classification:

6Cb, 6Cd

Region:

Inner Mongolia, China

Summary:

This paper proposes an anti-desertification strategy and ecological model for high-level reconstruction of' severely destroyed ecosystems and transformation of the micro-landscape. The proposal is based on an analysis of the two major processes of material differentiation in the desertification of inter-lacing agropastoral regions in semi-arid zones: the coarsenation of soil particles on ground surfaces caused by wind erosion and the accumulation of water in inter-dune depressions caused by vegetation destruction. The strategy seeks to fully utilize coarse sandy substrate as a valuable resource and to promote economical use of the accumulated water. Basic techniques of the ecological model for water-saving rice cultivation on sandy land include a layer of plastic film in the sandy soil, suitable rice varieties, water-saving, fertilizer control and zero tillage measures. The plastic film, although only 0.03-0.05 mm in thickness, effectively prevents water and fertilizer from downward seepage and salts from upward migration. The ecological model not only increases farmland productivity and soil fertility, but also acts as part of a comprehensive and integrated anti-desertification strategy. Series of water-saving rice plantations can be connected to forage cultivation and livestock grazing, forming a sound ecocirculation system to decrease grasslands pressure on large areas of sandy rangeland.

Author:

Liu Yingxin

Title:

About "The Chinese Desert Flora"

Publisher:

Journal of Desert Research. 13(3):14-17

Date:

1993

Language:

Chinese

Classification:

1, 2Ec

Region:

North China

Summary:

"The Chinese Desert Flora" is a three-volumes' work consisting of 2 252 000 Chinese characters, published between 1985 and 1992 by Science Press. Ninety families, 570 genera and 1693 species of plants are described along with 530 illustrative plates. A map of Chinese desert areas is appended to the first volume For each species the Chinese and Latin name, relevant literature, diagnosis, habitat, usage and keys of genera and species are provided. Name misuse and confusion over species in older literature is clarified and corrected. The addenda contains diagnosis of new taxa: one new genus, eight new species and five new varieties according to the International Code of Nomenclature. These volumes cover all plant genera and species in desert areas and sandy lands of the northern part of China. This work can fill gaps in knowledge about Chinese desert flora.

Authors:

Liu Yingxin (Institute of Desert Research, Academia Sinica, Lanzhou)

Title:

Thirty-five years of introducing and planting sand-fixing plants on moving sand dunes in Shapotou area

Publisher:

Journal of Desert Research. 11(1):13-19

Date:

1991

Language:

Chinese

Classification:

2Ed, 6Cb, 6Eb

Region:

Ningxia, China

Summary:

After 35 years of experience with sand-fixing plants on moving sand dunes under nonirrigated conditions in Shapotou area, the following principles for selection of sand-fixing species have been established. (1) Foreign species must be introduced from temperate sandylands and can withstand temperatures as low as -25°C; domestic species must be introduced from sandylands in semi-desert and desert zones with rainfall of less than 300 mm. Both pioneer and mid-stage plants in the successional processes should be considered for either windward or leeward slopes of moving sand dunes; tree species or species related to hydroseres should not be chosen. (2) Standards for the successful introduction include: higher survival rate, above 70 percent rapid growth, a persistent sand-fixing function in several years and the ability to produce flowers and seeds. They should have a longer life span (above ten years). Such species can be used to establish artificial vegetation on upwind slopes or fix sand on leeward slopes. It is best if they can regenerate naturally.

Authors:

Liu Yuhua and Zhang Chun (The Institute of Forestation and Sand Control Xinjiang Forest Academy of Sciences, Urumqi)

Title:

A study on the optimal model of sandbreak belt in Xinjiang

Publisher:

Arid Zone Research. 9(2):13-26

Date:

1992

Language:

Chinese

Classification:

6Cd, 6Ed

Region:

Xinjiang

Summary:

This paper presents studies on sandbreak effectiveness and other characteristics for different types of sandbreak belts. The amount of breaking sand and height and width of dunes in sandbreak forests of a single belt are determined using six parameters (structure of forest belt, permeability, composition of tree species, belt height, belt width and sand origin) Using variance analysis and the LSR method, the order of sandbreak efficacy for different types of sandbreak belts is as follows: single or multiple belt of forest and grass existing together, multiple belt of narrow and wooded tract, tight structure of single belt, sparse structure of single belt and aeration structure of single belt. Depending on natural conditions, degree of drift sand harm and water resource characteristics, the paper suggests an optimal model of sandbreak belt in the southern fringe of Junggar, Turpan and Tarim basins.

Author:

Liu Zhongmin (Northwestern Institute of Soil and Water Conservation)

Title:

Research on soil moisture balance in farmland under different rotation systems in loess hilly areas of South Ninrxia

Publisher:

Bulletin of Soil and Water Conservation. 12(6):21-25

Date:

1992

Language:

Chinese

Classification:

2B, 3Aa, 6Ed

Region:

Ningxia

Summary:

Location experiments were conducted to study soil moisture balance in farmland under different rotation systems in loess hilly area, of South Ningxia. The results show that rotation between grain and bean (i.e. spring pea-spring wheat-spring wheat-broom corn millet) could adjust, maintain and balance soil moisture within the rotation period; alfalfa can be used in the rotation of grass crops. Soil moisture in a layer of one metre is suitable for planting drought-resistance crops, such as millet, after alfalfa has grown five to six years; soil moisture in a layer of two metres can be replenished after drought-resistance crops were planted for two to three years. Long-term continuous cropping of spring wheat can lead to decreased soil fertility and increased pests, diseases and weeds, as well as reduced productivity which causes soil moisture problems.

Author:

Lu Shihua and Chen Yuchum (Institute of Plateau Atmospheric Physics, Chinese Academy of Sciences, Lanzhou, 730000)

Title:

The numerical simulation of the features of the planetary boundary layer of the oasis and the Gobi Desert in the arid region

Publisher:

Journal of Desert Research. 15(2)

Date: 1995

Language: Chinese

Classification:

2Cb, 2Ea

Region:

North China

Summary:

In order to simulate and research the influence of the features of the Planetary Boundary Line (PBL) of the oasis and the Gobi Desert and underlying surfaces on precipitation, a two dimensional, high resolution PBL model coupled with the Bates scheme is used. The underlying surface is desert which is several hundred kilometres long. Results show that the oasis transports little sensible heat to the PBL; the peak is 60 w/m². Latent heat is large with a peak at 400 w/m². Due to transportation of sensible and latent heat over the oasis, a cold wet air column appears in the boundary and lower air. This column can reach a height of 650 hPa and the ground layer and temperature difference can reach tour degrees C; this case is called the "oasis cold-wet effect". In the desert region with less latent heat transport, the peak is 100 w/m2, but sensible heat transport is about 400w/m2. A hot-dry air column can reach a height of 600 hPa in the boundary layer and lower air over the desert between the oasis. The maximum ground layer temperature difference is five degrees C; this case is called "desert hot-dry effect". Oases in the desert contribute to precipitation; cool-wet air transported by advection passes over the desert. It makes this layer unstable and precipitation increases over desert areas contiguous to the fringe of the oasis.

Author:

Liu Yuanboj

Title:

Dynamic variations in soil moisture caused by rainwater infiltration in bare sandyland

Publisher:

Journal of Desert Research. 15(2):143-150

Date:

1995

Classification:

2Eb, 3Aa

Language:

Chinese

Region:

Northwest China

Summary:

Shapotou Desert Experimental Research Station on the southern fringe of Tengger Desert has an annual rainfall of 186.2 mm. A neutron probe, tensiometer and automatic rain gauge were installed in bare sandy soil to measure soil moisture, soil moisture potential and rainfall amount and intensity. Results show that the water volume and suction power vary from high to low and from top to bottom during rainwater infiltration. The dividing line for brisk content of soil moisture is 0.6 m. Vertical transmission speed of soil moisture and rainfall conditions varies from 0.35-2.29 cm/hr. Infiltration speed of rainwater is low due to the existence of a dry sand layer. Soil water transmits quickly at first, then slows and tends to stabilize. Redistribution of rainwater plays a key role in the dynamic variation of soil moisture.

Authors:

Ma Xiaobo (Lanzhou Institute of Plateau Atmospheric Physics, Chinese Academy of Sciences, Lanzhou, Gansu 730000)

Title:

Study of drought, flood and precipitation trends in Inner Mongolia during the last 52 years

Publisher:

Plateau Meteorology. 12(4):450-457

Date:

1993

Language:

Chinese

Classification:

2Ea

Region:

Inner Mongolia

Summary:

This paper analyses drought, flood and precipitation trends based on monthly precipitation data from 1940-1991 collected at 25 stations in Inner Mongolia. Mean annual precipitation is 216.1 mm. Southern and western parts are arid zones; middle and eastern parts are semi-arid zones; annual precipitation variability is 15.6-38.0 percent. Droughts and floods are frequent in Inner Mongolia. The frequency of drought is higher than floods, but the frequency of severe floods is two times that of severe drought. Annual precipitation distribution is normal; it has quasi three year and 11-14-year periods. Annual precipitation increases average 0.34 mm over ten years. Annual precipitation increased at the rate of 5.13 mm/year in the 1980s and has continued to increase at the same rate in the 1990s.

Author:

Meng Xianxi (Changchun Institute of Geography, Academia Sinica)

Title:

Land desertification and controlling measures in southwest Songhua Jiang and Nen Jiang Plain

Publisher:

Scientia Geographical Sinica. 11(4):353-360

Date:

1991

Language:

Chinese

Classification:

3Ac, 3C, 4Aa, 4Ab, 4Ba, 6Ab, 6Cb, 6Cc

Region:

Northeast of China

Summary:

Natural factors influencing land desertification in Songhua Jiang and Nen Jiang Plain are as follows. (1) Neotectonic movement and vicissitudes of river bed development during the Quaternary created a wide deposit of sand in the river bed and floodplain, leaving large amounts of sand. (2) Windy and arid spring seasons in recent years have reduced precipitation making the area much drier, thus sand spreads more easily. Artificial factors influencing desertification include over cultivation, overgrazing and over harvesting of woodfuel. The authors propose the following measures to control land desertification. (1) Readjust the proportion of cultivated, forest and grassland; increase the proportion of forest and grassland. (2) Plant trees to prevent the harmful effects of wind and sand, including artificial ecological systems of arbour, shrub and grass on dunes, a compound ecological system of forest, grassland and farmland in flat areas and shelterbelt networks (3) Construct a model three-dimensional ecological system for agriculture between sand dunes and pasture. (4) In residential areas build a courtyard economic system which ties together daily life activities, production and ecology. (5) Invest in policies that support contract forms of' production.