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Characteristics of the Tengger dunefield, north-central China, and comparison with the central Australian dunefields
Journal of AridEnvironments (1986) 10, 97-101
Characteristics of the Tengger dunefield, north-central China, and comparison with the central Australian dunefields R. C. Buckley', W. Cherr] , Y. Liuj, & Z. Zhu] Accepted 31 October 1983 The Chinese desert dunefields are little-known outside China, since almost all the relevant literature is in Chinese. This note summarises soil and vegetation characteristics for a site in the Tengger dunefield of north central China, and provides a brief comparison with the central Australian dunefields. The Tengger dunes are transverse, mobile and up to 30 m high. The sands are unimodal and oligotrophic, with no catenary variation. Mean total phosphate and nitrogen contents are 290 and 16 p.p.m. respectively. Their vegetation is very sparse, consisting of isolated plants of Caragana korshinskii and Calligonum caput-medusae on the lower flanks, and small patches of Artemisia sphaerocephala in the interdune depressions. Most of the dunes are bare. The Tengger dunefields are at higher latitude and elevation than those of central Australia, and receive significantly higher rainfall, yet the Tengger dunes are bare whilst those in central Australia are densely vegetated, except on the crests. The difference is probably due to the lower soil nitrogen content of the Tengger dunes, and perhaps also to their greater mobility. Both these factors are themselves influenced by plant cover, however, in a positive feedback sense. Further comparative studies of dunefield ecosystem dynamics would be valuable in both theoretical and applied contexts.
Introduction The desert dunefields of China are largely unknown to the western scientific community, since almost all the relevant literature is in Chinese and the remainder in Russian or German. Existing information is summarised by Walter & Box (1983); it is largely broad-scale and descriptive. This note therefore summarises soil and vegetation characteristics for an area in the Ala Shan, which has been studied extensively over the past 20 years as part of an Academia Sinica research programme in dune stabilisation techniques (Chen, 1981; Huang & Song, 1981; Liu, 1981; Wang, 1981). The area concerned lies in the Tengger dunefield, which forms the southern part of the Badan Jinlin Desert in the Ala Shan region of central northern China. The Tengger dunefield lies largely within the Inner Mongolia Autonomous Region, near its borders with Gansu Province to the south-west and the Ningxia Autonomous Region to the southeast. The site described here is at 105° OD'E, 37° 40'N, immediately north of Shapotou. Its elevation is approximately 1300 m, and mean annual rainfall is approximately 200 mm. General characteristics of the Ala Shan region, including a photograph of the Tengger ('Tengri') dunes, and a brief plant list, were given by Walter & Box (1983). • ASPECT Consultant Group, P.O. Box 114, Eastwood, Australia 5063.
t Institute of Desert Research, Academia Sinica, Lanzhou, China. 0140-1963/86/020097+05 $03.00/0
© 1986 Academic Press Inc.
(London) Limited
98
R. C. BUCKLEY ET AL.
Soil The detailed description by Chen (1981) compares the soils of dunes partly or wholly stabilised by plantation techniques (to protect the Lanzhou-Beijing railway) with those of the unfixed shifting dunes of the Tengger dunefield to the north. Here only the latter are considered. The Tengger dunes are transverse and up to 30 m in height, and move downwind at 2-4 m/year. The rate of sand transport through a vertical slot 1 em wide and 10 em high has been measured at 3'2 g/min. There are no significant topographic gradients in physical or chemical soil properties, save for slightly greater mobility on the dune crests. Since the dunes are mobile, the actual body of sand comprising these crests is constantly changing. Mean characteristics for the top 0'75 m are summarised in Tables 1 and 2; the sands are unimodal and oligotrophic. Vegetation
The work of Liu (1981) was largely concerned with selection of species for dune stabilisation programmes. Here, only the native vegetation of the unfixed dunes is considered. The vegetation of the main field of shifting dunes, as opposed to its partially stabilised margins, is extremely sparse; small patches of Artemisia sphaerocephala occur in the deeper interdune depressions, and occasional plants of Caragana korshinskii and Calligonum caput-medusae appear on their lower flanks. Most dunes are completely bare. A number of native psammophytes are planted extensively for stabilisation in the dune margins (Liu, 1981); and the unfixed dunes overlying old terraces of Table 1: Soil characteristics, Tengger dunes: means of nine samples between 0 and 0'75 m depth Parameter
Mean
Standard deviation
Bulk density Porosity (%) Particle size distribution (%) (n = 36) 0'25-0'5 mm (1-2<1» 0'05-0'25 mm (2-4<1» <0'05 mm (>4<1» Infiltration Natural, after 4 mm rain: Infiltration depth (em) Soil moisture content (%) Experimental, under 12 mm head (mm/min) Bulk nutrient analysis Organic matter (p.p.m.) Carbonate (p.p.m.) Total P (p.p.m.) Total N (p.p.m.) Available N (p.p.m.) Soil solution pH HC0 3 (p.p.m.) CI- (p.p.m.) SO~- (p.p.m.) Ca2+ (p.p.m.) Mg2+ (p.p.m.) K+ + Na+ (p.p.m.)
1'66 38'0
0'01 0'6
5'4 93'2 0'3
2'9 3'1 0'46
6 3'6 12 710 1600 289 16 3'1
60 300 22 7 1'6
7'26 1'7 0'4 2'9 0'9 0'3 3'9
0'16 0'2 0'08 1'0 0'1 0'1 0'9
TENGGER DUNEFIELD
99
Table 2: Soil trace elements, Tengger dunes
Concentration, p.p.m. Element Ti Mn V
Cr Ni Co Sc Mg Fe Zn Cu
Sample I 3630 417 42 363 27
10 88 12100 1100 37 18
Sample 2 1480 112 18 66 16 9
16 4100 4800 21 5
the Yellow River, along the southern boundary of the Tengger dunefield, also support a relatively diverse flora (Table 3). The species concerned, however, are extremely sparse or entirely absent from the main dunefields. Comparison with central Australia Characteristics of the central Australian sandridge soils and vegetation were summarised by Buckley (1981a). Despite their higher latitude, higher elevation and higher mean annual rainfall, the Tengger dunes are almost devoid of vegetation, whereas the central Australian dunes are vegetated, except on the crests. There are two main possible reasons for the difference: greater mobility and lower fertility. Though there are no directly comparable measurements at present, the small-scale mass transport rates on the open crests of the larger Simpson and Gibson Desert sandridges are probably similar to those of the Tengger dunes. Being transverse, however, the Tengger dunes migrate downwind in their entirety, whereas on the longitudinal dunes of central Australia, sand travels along the ridges without shifting their overall position. Hence the sand surface may rise or fall by 40-60 em/a anywhere on the flanks of the Tengger dunes, whereas in central Australia net vertical movement of this magnitude is restricted to the bare secondary ridges and domes on the larger dunes. It seems unlikely that the difference in mobility is sufficient on its own to account for the difference in plant cover, however, firstly because the mobile 'noses' of longitudinal dunes migrating on the plain areas in central Australia are still more heavily vegetated than the Tengger dunes, and secondly because transverse dunes of comparable dimensions in the Thar Desert in India are also vegetated. There is also a feedback aspect; are the Tengger dunes bare because they are mobile, or mobile because they are bare? A second possible reason for the difference in plant cover is that the total nitrogen content of the Tengger dune sands is only one third of the mean total nitrogen content of central Australian dune crests, which themselves have only one third the total N content of the lower flanks of the central Australian dunes. In central Australia, the low soil N content of the dune crests prevents their successful colonisation by at least one species characteristic of the dune flanks (Buckley, 1983). The comparison of total soil N is tentative at present, since only nine measurements are available for the Tengger dunes, as compared to several hundred for central Australia. If the lower soil N content in the Tengger dunes is confirmed, however, it seems likely that it would be a significant impediment to plant growth, and hence a major factor in the relative sparseness of
100
R. C. BUCKLEY ET AL.
Table 3: Psammophytes from Tengger margins
• Agriophyllum arenarium Bieb. Agriophyllum squarrosum (L.) Moq. Alhagi pseudoalhagi Desv. Ammopiptanthus mongolicus (Maxim.) S. H. Cheng Apocynum lancifolium Russanov. • Artemisia anethifolia Web. Artemisia halodendron Turcz. • Artemisia ordosica Krasch. • Artemisia sphaerocephala Krasch. Atraphaxis braeteata A. Los. Atraphaxis pungens (L.) Ewersm. • Atraphaxis frutescens (L.) Ewersm. Calligonum caput-medusae Schrenk. • Calligonum mongolicum Turcz. • Caragana korshinskii Kom. • Caragana microphylla Lam. Conspermum hyssopifolium Iljin • Corispermum mongolicum Iljin Corispermum patelliforme Iljin Eleagnus angustifolia L. Gymnocarpos przewalskii Maxim. Haloxylon ammodendron Bge. Hedysarum fruticosum Pall. Hedysarum laeve Maxim. • Hedysarum mongolicum Turcz. • Hedysarum scoparium F. et M. Ixeris chinensis (Thunb.) Nakai Oxytropis aciphylla Ldb. Periploca sepium Bunge. • Psammochloa villosa (Trin.) Bar. • Pugionium calcaratum Komarov • Pugionium dolabratum Maxim. Reaumuria soongorica (Pall.) Maxim. Salix psammophylla C. Wang et ch. Y. Yang Tamarix hispida Willd. Tamarix ramosissima Ldb. Thermopsis lanceolata R.Br. Zygophyllum xanthoxylon Maxim. • Listed by Walter & Box (1983) for Ala Shan region, as 'vegetation of dunes and sand flats'.
plant cover in the Tengger dunefield. As with mobility, there is a possible feedback effect; the greater soil N content in the Australian sandridge soils may be due, at least in part, to direct or symbiotic N fixation by their plant cover. Arguing against this, however, the total organic matter content of the Tengger dunes is over twice that of the Australian dune crests. Either or both of these two factors may be involved, and they are by no means the only possibilities. Besides their intrinsic interest and their relevance to the evolution of the dunefield ecosystems (Buckley, 1981b), further comparative studies of the factors controlling plant cover on these desert dunefields would be valuable in applied fields such as the design of dune stabilisation strategies, which are a practical requirement in both continents. This note follows a visit by RCB to the Institute of Desert Research and two of its field stations in June 1983. This visit was funded by the Australia-China Council, and administrative and technical assistance was provided by the Foreign Affairs Bureau of Academia Sinica and by the
TENGGER DUNEFIELD
101
staff of the D.R.I. In particular, the assistance of Yang You-lin in interpreting innumerable scientific discussions between the authors, and in translating vital portions of the original paper by C. W. is gratefully acknowledged.
References Buckley, R. C. (1981a). Central Australian sandridges.Journal of Arid Environments, 4: 91-101. Buckley, R. C. (1981b). Parallel dunefield ecosystems: southern Kalahari and central Australia. Journal of Arid Environments, 4: 287-298. Buckley, R. C. (1983). Soil nitrogen requirements of tropical sandridge plants. Biotropica, 15: 77-78. Chen, W. 1981. The changes in soil properties after an effort in artificial sand-fixation and plantation in the Shapotou area.' Journal ofDesert Research (China), 1: 40-48. Huang, Z. & Song, B. (1982). The utilisation and improvement of pasture in the Ordos Region.' Memoirs of the AcademiaSinica Institute of Desert Research, Lanzhou, 1: 19-38. Liu, Y. 1981. Selection of plant species for fixing shifting sands in desert and semi-desert zones in China.' Memoirs of theAcademiaSinica Institute ofDesert Research, Lanzhou, 1: 39-62. Liu, Y. (1982). Walter, H. & Box, E. O. (1983). The deserts of central Asia. In West, N.E. (Ed.), Temperate Deserts and Semi-deserts; Ecosystems of the World,S: 193-236. Amsterdam: Elsevier. Wang, K. (1981). Fixation of shifting sands on both sides of the Baotou-Lanzhou railway in Shapotou. * Memoirs of the Academia Sinica Institute ofDesert Research, 1: 123-133. 'in Chinese
Characteristics of the Tengger dunefield, north-central China, and comparison with the central Australian dunefields R. C. Buckley', W. Cherr] , Y. Liuj, & Z. Zhu] Accepted 31 October 1983 The Chinese desert dunefields are little-known outside China, since almost all the relevant literature is in Chinese. This note summarises soil and vegetation characteristics for a site in the Tengger dunefield of north central China, and provides a brief comparison with the central Australian dunefields. The Tengger dunes are transverse, mobile and up to 30 m high. The sands are unimodal and oligotrophic, with no catenary variation. Mean total phosphate and nitrogen contents are 290 and 16 p.p.m. respectively. Their vegetation is very sparse, consisting of isolated plants of Caragana korshinskii and Calligonum caput-medusae on the lower flanks, and small patches of Artemisia sphaerocephala in the interdune depressions. Most of the dunes are bare. The Tengger dunefields are at higher latitude and elevation than those of central Australia, and receive significantly higher rainfall, yet the Tengger dunes are bare whilst those in central Australia are densely vegetated, except on the crests. The difference is probably due to the lower soil nitrogen content of the Tengger dunes, and perhaps also to their greater mobility. Both these factors are themselves influenced by plant cover, however, in a positive feedback sense. Further comparative studies of dunefield ecosystem dynamics would be valuable in both theoretical and applied contexts.
Introduction The desert dunefields of China are largely unknown to the western scientific community, since almost all the relevant literature is in Chinese and the remainder in Russian or German. Existing information is summarised by Walter & Box (1983); it is largely broad-scale and descriptive. This note therefore summarises soil and vegetation characteristics for an area in the Ala Shan, which has been studied extensively over the past 20 years as part of an Academia Sinica research programme in dune stabilisation techniques (Chen, 1981; Huang & Song, 1981; Liu, 1981; Wang, 1981). The area concerned lies in the Tengger dunefield, which forms the southern part of the Badan Jinlin Desert in the Ala Shan region of central northern China. The Tengger dunefield lies largely within the Inner Mongolia Autonomous Region, near its borders with Gansu Province to the south-west and the Ningxia Autonomous Region to the southeast. The site described here is at 105° OD'E, 37° 40'N, immediately north of Shapotou. Its elevation is approximately 1300 m, and mean annual rainfall is approximately 200 mm. General characteristics of the Ala Shan region, including a photograph of the Tengger ('Tengri') dunes, and a brief plant list, were given by Walter & Box (1983). • ASPECT Consultant Group, P.O. Box 114, Eastwood, Australia 5063.
t Institute of Desert Research, Academia Sinica, Lanzhou, China. 0140-1963/86/020097+05 $03.00/0
© 1986 Academic Press Inc.
(London) Limited
98
R. C. BUCKLEY ET AL.
Soil The detailed description by Chen (1981) compares the soils of dunes partly or wholly stabilised by plantation techniques (to protect the Lanzhou-Beijing railway) with those of the unfixed shifting dunes of the Tengger dunefield to the north. Here only the latter are considered. The Tengger dunes are transverse and up to 30 m in height, and move downwind at 2-4 m/year. The rate of sand transport through a vertical slot 1 em wide and 10 em high has been measured at 3'2 g/min. There are no significant topographic gradients in physical or chemical soil properties, save for slightly greater mobility on the dune crests. Since the dunes are mobile, the actual body of sand comprising these crests is constantly changing. Mean characteristics for the top 0'75 m are summarised in Tables 1 and 2; the sands are unimodal and oligotrophic. Vegetation
The work of Liu (1981) was largely concerned with selection of species for dune stabilisation programmes. Here, only the native vegetation of the unfixed dunes is considered. The vegetation of the main field of shifting dunes, as opposed to its partially stabilised margins, is extremely sparse; small patches of Artemisia sphaerocephala occur in the deeper interdune depressions, and occasional plants of Caragana korshinskii and Calligonum caput-medusae appear on their lower flanks. Most dunes are completely bare. A number of native psammophytes are planted extensively for stabilisation in the dune margins (Liu, 1981); and the unfixed dunes overlying old terraces of Table 1: Soil characteristics, Tengger dunes: means of nine samples between 0 and 0'75 m depth Parameter
Mean
Standard deviation
Bulk density Porosity (%) Particle size distribution (%) (n = 36) 0'25-0'5 mm (1-2<1» 0'05-0'25 mm (2-4<1» <0'05 mm (>4<1» Infiltration Natural, after 4 mm rain: Infiltration depth (em) Soil moisture content (%) Experimental, under 12 mm head (mm/min) Bulk nutrient analysis Organic matter (p.p.m.) Carbonate (p.p.m.) Total P (p.p.m.) Total N (p.p.m.) Available N (p.p.m.) Soil solution pH HC0 3 (p.p.m.) CI- (p.p.m.) SO~- (p.p.m.) Ca2+ (p.p.m.) Mg2+ (p.p.m.) K+ + Na+ (p.p.m.)
1'66 38'0
0'01 0'6
5'4 93'2 0'3
2'9 3'1 0'46
6 3'6 12 710 1600 289 16 3'1
60 300 22 7 1'6
7'26 1'7 0'4 2'9 0'9 0'3 3'9
0'16 0'2 0'08 1'0 0'1 0'1 0'9
TENGGER DUNEFIELD
99
Table 2: Soil trace elements, Tengger dunes
Concentration, p.p.m. Element Ti Mn V
Cr Ni Co Sc Mg Fe Zn Cu
Sample I 3630 417 42 363 27
10 88 12100 1100 37 18
Sample 2 1480 112 18 66 16 9
16 4100 4800 21 5
the Yellow River, along the southern boundary of the Tengger dunefield, also support a relatively diverse flora (Table 3). The species concerned, however, are extremely sparse or entirely absent from the main dunefields. Comparison with central Australia Characteristics of the central Australian sandridge soils and vegetation were summarised by Buckley (1981a). Despite their higher latitude, higher elevation and higher mean annual rainfall, the Tengger dunes are almost devoid of vegetation, whereas the central Australian dunes are vegetated, except on the crests. There are two main possible reasons for the difference: greater mobility and lower fertility. Though there are no directly comparable measurements at present, the small-scale mass transport rates on the open crests of the larger Simpson and Gibson Desert sandridges are probably similar to those of the Tengger dunes. Being transverse, however, the Tengger dunes migrate downwind in their entirety, whereas on the longitudinal dunes of central Australia, sand travels along the ridges without shifting their overall position. Hence the sand surface may rise or fall by 40-60 em/a anywhere on the flanks of the Tengger dunes, whereas in central Australia net vertical movement of this magnitude is restricted to the bare secondary ridges and domes on the larger dunes. It seems unlikely that the difference in mobility is sufficient on its own to account for the difference in plant cover, however, firstly because the mobile 'noses' of longitudinal dunes migrating on the plain areas in central Australia are still more heavily vegetated than the Tengger dunes, and secondly because transverse dunes of comparable dimensions in the Thar Desert in India are also vegetated. There is also a feedback aspect; are the Tengger dunes bare because they are mobile, or mobile because they are bare? A second possible reason for the difference in plant cover is that the total nitrogen content of the Tengger dune sands is only one third of the mean total nitrogen content of central Australian dune crests, which themselves have only one third the total N content of the lower flanks of the central Australian dunes. In central Australia, the low soil N content of the dune crests prevents their successful colonisation by at least one species characteristic of the dune flanks (Buckley, 1983). The comparison of total soil N is tentative at present, since only nine measurements are available for the Tengger dunes, as compared to several hundred for central Australia. If the lower soil N content in the Tengger dunes is confirmed, however, it seems likely that it would be a significant impediment to plant growth, and hence a major factor in the relative sparseness of
100
R. C. BUCKLEY ET AL.
Table 3: Psammophytes from Tengger margins
• Agriophyllum arenarium Bieb. Agriophyllum squarrosum (L.) Moq. Alhagi pseudoalhagi Desv. Ammopiptanthus mongolicus (Maxim.) S. H. Cheng Apocynum lancifolium Russanov. • Artemisia anethifolia Web. Artemisia halodendron Turcz. • Artemisia ordosica Krasch. • Artemisia sphaerocephala Krasch. Atraphaxis braeteata A. Los. Atraphaxis pungens (L.) Ewersm. • Atraphaxis frutescens (L.) Ewersm. Calligonum caput-medusae Schrenk. • Calligonum mongolicum Turcz. • Caragana korshinskii Kom. • Caragana microphylla Lam. Conspermum hyssopifolium Iljin • Corispermum mongolicum Iljin Corispermum patelliforme Iljin Eleagnus angustifolia L. Gymnocarpos przewalskii Maxim. Haloxylon ammodendron Bge. Hedysarum fruticosum Pall. Hedysarum laeve Maxim. • Hedysarum mongolicum Turcz. • Hedysarum scoparium F. et M. Ixeris chinensis (Thunb.) Nakai Oxytropis aciphylla Ldb. Periploca sepium Bunge. • Psammochloa villosa (Trin.) Bar. • Pugionium calcaratum Komarov • Pugionium dolabratum Maxim. Reaumuria soongorica (Pall.) Maxim. Salix psammophylla C. Wang et ch. Y. Yang Tamarix hispida Willd. Tamarix ramosissima Ldb. Thermopsis lanceolata R.Br. Zygophyllum xanthoxylon Maxim. • Listed by Walter & Box (1983) for Ala Shan region, as 'vegetation of dunes and sand flats'.
plant cover in the Tengger dunefield. As with mobility, there is a possible feedback effect; the greater soil N content in the Australian sandridge soils may be due, at least in part, to direct or symbiotic N fixation by their plant cover. Arguing against this, however, the total organic matter content of the Tengger dunes is over twice that of the Australian dune crests. Either or both of these two factors may be involved, and they are by no means the only possibilities. Besides their intrinsic interest and their relevance to the evolution of the dunefield ecosystems (Buckley, 1981b), further comparative studies of the factors controlling plant cover on these desert dunefields would be valuable in applied fields such as the design of dune stabilisation strategies, which are a practical requirement in both continents. This note follows a visit by RCB to the Institute of Desert Research and two of its field stations in June 1983. This visit was funded by the Australia-China Council, and administrative and technical assistance was provided by the Foreign Affairs Bureau of Academia Sinica and by the
TENGGER DUNEFIELD
101
staff of the D.R.I. In particular, the assistance of Yang You-lin in interpreting innumerable scientific discussions between the authors, and in translating vital portions of the original paper by C. W. is gratefully acknowledged.
References Buckley, R. C. (1981a). Central Australian sandridges.Journal of Arid Environments, 4: 91-101. Buckley, R. C. (1981b). Parallel dunefield ecosystems: southern Kalahari and central Australia. Journal of Arid Environments, 4: 287-298. Buckley, R. C. (1983). Soil nitrogen requirements of tropical sandridge plants. Biotropica, 15: 77-78. Chen, W. 1981. The changes in soil properties after an effort in artificial sand-fixation and plantation in the Shapotou area.' Journal ofDesert Research (China), 1: 40-48. Huang, Z. & Song, B. (1982). The utilisation and improvement of pasture in the Ordos Region.' Memoirs of the AcademiaSinica Institute of Desert Research, Lanzhou, 1: 19-38. Liu, Y. 1981. Selection of plant species for fixing shifting sands in desert and semi-desert zones in China.' Memoirs of theAcademiaSinica Institute ofDesert Research, Lanzhou, 1: 39-62. Liu, Y. (1982). Walter, H. & Box, E. O. (1983). The deserts of central Asia. In West, N.E. (Ed.), Temperate Deserts and Semi-deserts; Ecosystems of the World,S: 193-236. Amsterdam: Elsevier. Wang, K. (1981). Fixation of shifting sands on both sides of the Baotou-Lanzhou railway in Shapotou. * Memoirs of the Academia Sinica Institute ofDesert Research, 1: 123-133. 'in Chinese