Loading...

Current Issue

07 December 2011, Volume 3 Issue 4 Previous Issue    Next Issue
For Selected: View Abstracts Toggle Thumbnails
Articles
Study of the Species Diversity of Plant Communities in the Northern Slopes of Karlik Range—Naomaohu
ZHANG Hai-Yan, QIAN Yi-Bing, DUAN Shi-Min, WANG Zhong-Chen, HUANG Cai-Xia
Journal of Arid Land. 2011, 3 (4): 231-321.  
Abstract ( 514 )     PDF (0KB) ( 709 )  
Based on data from 22 sample sites, species diversity of plant communities in the northern slope of Karlike Range—Naomaohu were discussed. The Karlike Range is situated in the eastern section of the Tianshan Mountains, and Naomaohu is located between the Altai Mountains and Tianshan Mountains. The research on the botany has not been found in this region yet. Applying the analytical method of species diversity indices, the composition, species, and diversity of the vegetation in the study area are discussed this paper. The results show that the higher plants in this area have 33 families, 93 genera and 133 species, which are dominated by Compositae, Gramineae, Chenopodiaceae, Leguminosae, Ranunculaceae, Cyperaceae and so on. The composition of plant life-forms is mainly herbaceous. Principal component analysis of indices shows that, in terms of diversity indices, the species richness index (R), Pielou evenness index (Jsi), Shannon-Wiener diversity index (H) and Simpson dominance index (C) can better describe the characteristics of the plant communities in the study area. The vegetation types are varied in study area, but the vegetation vertical zonal spectrum is incomplete and there is no mountain meadow. Compared with other mountains on the northern slopes of the Tianshan Mountains, the distributing boundary of the grasslands in Karlik Range is high. Analyzing the species diversity indices of different plant communities indicates that the diversity index, species richness index and evenness index display a common trend, while the dominance index is on the contrary. The fluctuation of the evenness index is very slight, indicates that the distribution of species in different plant communities is quite uniform. The four types of species diversity indices can well reflect the differences between species composition and community organization of different plant communities. With the rising of elevations, the species diversity, evenness and richness increase gradually at first and then reduce. The plant species diversities are lower in the desert ecosystem and higher in the high mountain ecosystem and reach the maximum at the intermediate zone. This is due to the allocation of heat, temperature, precipitation and other environmental factors favorable in the intermediate zone.
Research Articles
Breeding system and its consequence on fruit set of a rare sand dune shrub Eremosparton songoricum (Fabaceae: Papilionoideae): implications for conservation
DaoYuan ZHANG, Xiang SHI, JianCheng WANG, HuiLiang LIU John F GASKIN
Journal of Arid Land. 2011, 3 (4): 231-239.   DOI: 10.3724/SP.J.1227.2011.00231
Abstract ( 3198 )     PDF (1948KB) ( 3554 )  
The breeding system and its consequence on fruit set of Eremosparton songoricum (Litv.) Vass., a rare shrubby legume occurring in moving or semi-fixed sand dunes of Central Asian deserts, were examined by manipulative experiments and observational studies in natural populations during the period of 2007–2009. The results showed that E. songoricum exhibits a mixed mating system. It is self-compatible, but depends strictly on pollinators to set fruits. Only two effective pollinators were detected and they triggered the specialized pollination mechanism (a ‘brush type’ and ‘tripping mechanism’). Geitonogamy becomes predominant in natural populations, because (74.5±1.3)% of visiting activity happened within or between inflorescences and (24.3±1.4)% occurred between ramets. As a result, inbreeding depression caused by geitonogamous selfing inevitably happened under natural conditions, showing 2.36 times less fruit set than was achieved by hand cross-pollination. The results ex-plained the rarity of the species due to its breeding system, and will assist to develop suitable conservation strategies in severe desert environments.
Monophyly and infrageneric variation of Corispermum L. (Chenopodiaceae), evidence from sequence data psbB-psbH, rbcL and ITS
JuanJuan XUE, MingLi ZHANG
Journal of Arid Land. 2011, 3 (4): 240-253.   DOI: 10.3724/SP.J.1227.2011.00240
Abstract ( 3450 )     PDF (1766KB) ( 6061 )  
Corispermum is one of the most problematic taxonomic genera in Chenopodiaceae. To understand the phylogeny and infrageneric variation of Corispermum, we sequenced the nuclear ribosomal ITS region and two chloroplast DNA regions (rbcL and psbB-psbH) of 22 species and three varieties of Corispermum and the related genus Agriophyllum. Several representative species of Salsola, Suaeda, Chenopodium, Kalidium and Camphorosma served as outgroups. Our phylogenetic trees confirm that the tribe Corispermeae is monophyletic, Corispermum and Agriophyllum have a close relationship. Corispermum is demonstrated to be monophyletic, and contains at least four clades which, consequently, are served as the foundation of the infrageneric sectional variation of Corispermum, in terms of a combination of molecular data and morphological characters. The evolution of morphological characters for fruit wing and apex, two important characters in generic classification, is consistent with the sectional division of Corispermum, especially to the East Asian and Chinese taxa.
Altitudinal patterns of stand structure and herb layer diversity of Picea schrenkiana forests in the central Tianshan Mountains, Northwest China
LiPing LI, XiangPing WANG, Stefan ZERBE, LiYun ZHANG, JingYun FANG
Journal of Arid Land. 2011, 3 (4): 254-260.   DOI: 10.3724/SP.J.1227.2011.00254
Abstract ( 3432 )     PDF (727KB) ( 3546 )  
Altitude is a useful indicator to examine patterns of forest structure and species diversity in relation to environmental factors. In this study, the altitude patterns of forest stand structure and species diversity were analyzed across 20 plots in the Tianchi Nature Reserve, Northwest China. The results showed that mean stem height (Hm), maximum stem height (Hmax) and mean stem diameter at breast height (Dm) of Picea schrenkiana trees all decreased significantly with increasing altitude. Potential tree height (H*) decreased while stem taper increased significantly as altitude increased, suggesting remarkable altitudinal changes in biomass allocation between the diameter and height growth of Picea schrenkiana. Understory herbaceous richness increased significantly with increasing altitude, or with decreasing total basal area (TBA), Hm and stand volume (Volume). High light availability for understory herbs might account for the higher species richness at high altitude. Sorensen Index decreased significantly with the increase in altitude intervals, while the Cody Index demonstrated a converse pattern, suggesting greater differences in species composition with larger distances.
Anatomical and morphological characteristics of Populus euphratica in the lower reaches of Tarim River under extreme drought environment
Li ZHUANG, YaNing CHEN, WeiHong LI, ZhongKe WANG
Journal of Arid Land. 2011, 3 (4): 261-267.   DOI: 10.3724/SP.J.1227.2011.00261
Abstract ( 4011 )     PDF (1268KB) ( 5279 )  
Populus euphratica Oliv. is an old desert tree species that has been naturalized and invades zones along the watercourses in many arid and semiarid regions. The plant species developed some plasticity to adapt to the gradual environmental gradients. The aim of this study was to test the hypothesis that the changes in leaf morphology of P. euphratica reflect the adaptability of the plant to the unique environment of the lower reaches of Tarim River in China. The foliar architecture, blade epidermal and internal anatomies of P. euphratica were analyzed at different sites along the Tarim River. Compared with the abaxial surface of the leaves, their adaxial surface has more hairs, a greater stomatal density and opening, higher mesophyll proportion, and increased blade thickness, palisade width, and epidermal thickness. The long trichome of the roots found at site 6 in the Yinsu section may be an adapted structure of the plants in arid areas. The mature leaves of P. euphratica have comparatively more epidermis and cuticles, well developed palisades and more chloroplasts at different sites compared to the young leaves. Foliar morphological and anatomical variability in P. euphratica may be considered an adaptive advantage that enables leaves to develop and function in different habitats, marked by strong variations in solar radiation, air temperature, humidity and water table.
Spatial heterogeneity of soil water content in the reversion process of desertification in arid areas
QuanLin MA, Fang CHENG, YouJun LIU, FangLin Wang, DeKuai ZHANG, HuJia JIN
Journal of Arid Land. 2011, 3 (4): 268-277.   DOI: 10.3724/SP.J.1227.2011.00268
Abstract ( 3613 )     PDF (4040KB) ( 3480 )  
 Sandy soils in arid, rain-fed environments have low and limited water content, which is a principal factor limiting vegetation development, and a key constraint controlling the structure and functions of the ecological systems in arid areas. The spatial heterogeneity of soil water content is a major soil property, and a focus of soil science and hydrology. On the southern edge of the Tengger Desert, sample plots were selected from mobile sand dunes in desertified lands that had been enclosed for 5, 15 and 25 years, respectively. This study explored the dynamic and spatial heterogeneity of soil water content in these different layers of soil that were also in the reversion process of desertification. The results showed that the soil water content of the mobile sand dunes was highest when in the initial stages of the reversion process of desertification, while the soil water content in the 0–20 cm, 20–40 cm and 40–60 cm layers of soil was 1.769%, 3.011%, and 2.967% respectively, presenting a restoring tendency after 25 years of enclosure. There were significant differences, as a whole, in the soil water content among different restoration stages and different soil layers, respectively. Changes in soil water content, in different soil layers, at different restoration stages, exhibited exponential or spherical patterns. The spatial distribution of soil water content exhibited a mosaic patch pattern with obvious spatial heterogeneity. The ratio of the heterogeneity of spatial autocorrelation to gross spatial heterogeneity was greater than 50%. The gross spatial heterogeneity of the 0–20 cm layer of soil improved gradually, while those of the 20–40 cm and 40–60 cm layers improved initially, then weakened in the reversion process of desertification. This study revealed that restoration with sand-binding vegetation reduced soil water content, and increased its spatial heterogeneity in arid areas. However, after 25 years of vegetation-soil system restoration, the soil water content started to increase and its spatial heterogeneity started to weaken. These results will further benefit the understanding of the ecological mechanism between soil water and sand-binding vegetation.
Regional partitioning of agricultural non-point source pollution in China using a projection pursuit cluster model
XinHu LI, ChengYi ZHAO, Bin WANG, Garry FENG
Journal of Arid Land. 2011, 3 (4): 278-284.   DOI: 10.3724/SP.J.1227.2011.00278
Abstract ( 3576 )     PDF (441KB) ( 3628 )  
A projection pursuit cluster (PPC) model was used to analyze the regional partitioning of agricultural non-point source pollution in China. The environmental factors impacting the agricultural non-point source pollution were compiled into a projection index to set up the projection index function. A novel optimization algorithm called Free search (FS) was introduced to optimize the projection direction of the PPC model. By making the appropriate improvements as we explored the use of the algorithm, it became simpler, and developed better exploration abilities. Thus, the multi-factor problem was converted into a single-factor cluster, according to the projection, which successfully avoided subjective disturbance and produced objective results. The cluster results of the PPC model mirror the actual regional partitioning of the agricultural non-point source pollution in China, indicating that the PPC model is a powerful tool in multi-factor cluster analysis, and could be a new method for the regional partitioning of agricultural non-point source pollution.
Reviews
Application of stable isotope techniques to the study of soil salinization
YongQin CUI, JianYing MA, Wei SUN
Journal of Arid Land. 2011, 3 (4): 285-291.   DOI: 10.3724/SP.J.1227.2011.00285
Abstract ( 2990 )     PDF (426KB) ( 4819 )  
 In this paper, we reviewed the progress in the application of stable isotope techniques to the study of soil salinization. As a powerful technique, stable isotopes have been widely used in the studies of soil water evaporation, the dynamics of soil salinization and salt-tolerant plant breeding. The impact of single environmental factors on plant isotope composition has been the focus of previous studies. However, the impact of multiple environmental factors on plant isotope composition remains unclear and needs to be carefully studied. In order to gain insights into soil salinization and amelioration, especially soil salinization in arid and semiarid areas, it is essential to employ stable isotope techniques and combine them with other methods, such as located field observation and remote sensing technology.
Melting and shrinkage of cryosphere in Tibet and its impact on the ecological environment
JianGuo ZHANG, YingLi WANG, YunSong JI, DeZhi YAN
Journal of Arid Land. 2011, 3 (4): 292-299.   DOI: 10.3724/SP.J.1227.2011.00292
Abstract ( 2494 )     PDF (423KB) ( 3537 )  
Global warming is having a profound impact on global ecological systems, and has inevitably induced changes in the cryosphere, one of the five layers of the earth. Major changes include the shrinking and reduction in the area and volume of both the mountain glaciers and the ice caps covering the North and South poles, and the melting of permafrost and thickening of the active frost layer. Swift changes in the cryosphere have inevitably induced ecological and environmental changes in its zone. While some of these changes are beneficial to mankind, such as an increase in water circulation, short term increases in water volumes and the enlargement of the cultivatable area, others are extremely hazardous, like the flooding of lowlands caused by an increased sea level elevation, debris flow caused by glaciers, glacier lake bursts, undermined building safety caused by permafrost melting, the deterioration of alpine cold meadows, and the surface aridization and desertification of land. Tibet, having a major part of the cryosphere in China, is home to the most widely spread glaciers and permafrost, which play a vital role in regulating water resources, climate, environment and the ecological safety in China and Asia. However, due to global warming, the glaciers and permafrost in Tibet have recently changed dramatically, exhibiting shrinkage and melting, which threatens long-term water resources, and the ecological and environmental safety of China. Based on existing research, this paper discusses the relationship between global warming and the melting and shrinkage of the cryosphere. The results show that the cryosphere’s melting and shrinkage in Tibet are the direct result of global warming. The melting of glaciers has led to a series of disasters, such as changes in river runoff, the heightened frequency of debris flows induced by glaciers and the outbursts of glacier lakes. The melting of the permafrost also resulted in a series of ecological and environmental problems in Tibet, such as the degrada-tion and population succession of the alpine grassland and meadows, the aridization of the land surface, and the occurrence of freeze-thaw erosion.
Brief Communication
A new ornithological record, Pechora Pipit Anthus gustavi Swinhoe, 1863, from Xinjiang
Peng DING, Ming MA, Ying CHEN, Geoff CAREY, Paul HOLT
Journal of Arid Land. 2011, 3 (4): 300-302.   DOI: 10.3724/SP.J.1227.2011.00300
Abstract ( 2894 )     PDF (1084KB) ( 2475 )  
On 15 September, 2010, a Pechora Pipit Anthus gustavi Swinhoe was found in the Hami prefecture (41°13′N and 93°29′E, 1,143 m a.s.l.), Xinjiang, during the period of a comprehensive scientific survey in Lop Nur region. The bird, which was photographed, is a new avian record for Xinjiang. The pipit reproduces in northern Eurasia, mainly in wide meadows and low hills, and can be found in open forests and nearby residential areas in the process of on migration. The species is an insectivore and is a rare migrant or vagrant in Xinjiang. The geographical distribution, character, habitat, ecological habit and subspecies of the Pechora Pipit were discussed in this paper.
Fauna of Heteroptera in the deserts of Kazakhstan
Yesenbekova Perizat Abdykairovna
Journal of Arid Land. 2011, 3 (4): 303-305.   DOI: 10.3724/SP.J.1227.2011.303
Abstract ( 3194 )     PDF (349KB) ( 4000 )  
Heteroptera is an important group among the insect orders, not only for its number of species, but also for its distribution and food preference. A total of 405 species of Heteroptera were identified in the desert areas of Kazakhstan, in which 158 species are distributed in the sandy deserts, 105 species in the Solonchak deserts, 75 species in the clay deserts, and 67 species in the rocky-rubbly deserts.