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2019, 11 (5) Online: 31 October 2019 Previous issue
  • Origin and advances in implementing blowing-snow effects in the Community Land Model
  • ZeYong Hu,ZhiPeng Xie
  • DOI: 10.3724/SP.J.1226.2019.00335.
  • 2019, Vol.11 (5): 335–339 Abstract ( 189) HTML ( 20) PDF (938 KB) ( 156 )
  • now cover on the Tibetan Plateau (TP) is closely related to regional and continental biological and hydrological processes. The vast snow cover, special climatic conditions, and sparse vegetative cover over the TP facilitate the occurrence of blowing snow, leading to substantial heterogeneities in the snow cover and great promotion in the moisture supply from the land surface to the overlying atmospheric boundary layer. However, blowing-snow processes are significantly misrepresented or even neglected in current models, which causes considerable uncertainties of numerical model simulations and leads to erroneous estimates of snow-related processes in mountainous terrain. We present in this paper a brief review of our work in the past 5 years to serve as a basis for further development and improvement of the land-surface model. These studies can be divided into three parts: detection of the problems, development of the land-surface model, and application of the coupled model over the TP (the logical framework is presented in Figure 1). The origin and advances in the development of a land-surface model with consideration of blowing-snow effects are described herein; and the importance of blowing-snow processes in the land-surface model, especially over the TP, is highlighted. We expect that the blowing-snow studies over the TP will play a key role in documenting and understanding the land-surface processes (LSPs) and the cryospheric changes over the TP.

  • Analysis of chaotic climatic process in the Tarim River Basin (I)
  • ZuHan Liu
  • DOI: 10.3724/SP.J.1226.2019.00340.
  • 2019, Vol.11 (5): 340–349 Abstract ( 794) HTML ( 59) PDF (1711 KB) ( 129 )
  • Based on observational data obtained from 1961 to 2011 in the Tarim River Basin, China, we investigated the chaotic dynamics of temperature, precipitation, relative humidity, and evaporation. The main findings are as follow: (1) The four data series have significant chaotic and fractal behaviors, which are the result of the evolution of a nonlinear chaotic dynamic system. The climatic process in the Tarim River Basin also has deterministic and stochastic characteristics. (2) To describe the temperature, precipitation, relative humidity, and evaporation dynamics, at least three independent variables at daily scale are required; in terms of complexity, their order is evaporation > temperature > precipitation > relative humidity. (3) Their respective largest Lyapunov exponent λ 1 shows the order of their degree of complexity is relative humidity > temperature > precipitation ≈ evaporation; the maximum time scales for which the four systems can be predicted are 17 days, 17 days, 16 days, and 16 days, if calculated separately. (4) The Kolmogorov entropy K illustrates that the complexity of the nonlinear precipitation system is much greater than that of the other three systems. Both temperature and evaporation systems exhibit weaker chaotic behavior, their predictability is better, and the degree of complexity is less than that of the other two factors.

  • Seed germination and seedling growth of Pycnanthus angolensis (Welw.) Warb., African false nutmeg
  • Sakpere A.M.A.
  • DOI: 10.3724/SP.J.1226.2019.00350.
  • 2019, Vol.11 (5): 350–359 Abstract ( 4463) HTML ( 30925) PDF (2153 KB) ( 430 )
  • This study investigated the germination behavior and seedling growth of Pycnanthus angolensis seeds. The germination study was carried out in the laboratory and included pretreatment studies and observation of the seed-germination process. For each treatment, three replications of 20 seeds were sown in a transparent plastic germination box (12cm × 22cm × 5cm) lined with moistened filter paper at room temperature. To monitor seedling growth, seedlings were transplanted into pots filled with topsoil and laid out in a completely randomized design. Ten seedlings replicated thrice were measured monthly; and the shoot height, leaf area, and root length, as well as the fresh and dry weights of the seedlings, were recorded. Results showed that mechanically scarified seeds exhibited the significantly highest germination percent (83.33%, P <0.005), followed by control seeds (70.83%), whereas seeds treated with 98% sulphuric acid (H2SO4) displayed the lowest germination percent (1.67). The endospermous seeds exhibited cryptogeal germination, while seeds stored for a month (with or without arils) failed to germinate. During seed germination, radicle protrusion continued with a pseudo-opening of the root, through which the brownish cotyledonary petiole was emitted, thus releasing the plumule at the posterior position. Moreover, P. angolensis exhibited a slow growth rate, attaining a shoot height of 73 cm within a year. The highest positive change in leaf number and area was recorded in the fourth month, a period during which the least change in shoot height occurred. The study concluded that mechanical scarification of the seeds ensured significant and faster germination than chemical scarification or no treatment at all. Additionally, P. angolensis displayed a cryptogeal germination, with the seedling growth of the tree species observed to be slow.

  • Soil hydraulic conductivity and its influence on soil moisture simulations in the source region of the Yellow River―take Maqu as an example
  • DongYu Jia,Jun Wen,Xin Wang,ZuoLiang Wang
  • DOI: 10.3724/SP.J.1226.2019.00360.
  • 2019, Vol.11 (5): 360–370 Abstract ( 122) HTML ( 13) PDF (2177 KB) ( 163 )
  • aturated hydraulic conductivity and unsaturated hydraulic conductivity which are influenced by soil are two important factors that affect soil water transport. In this paper, data supplied by the Chinese Academy of Sciences are used to determine true unsaturated hydrology values. Furthermore, in combination with observed, model simulation and experimental data, an improved saturated hydraulic conductivity parameterization scheme is carried out in CLM4.5 at a single point in the summer. The main results show that: (1) After improving saturated hydraulic conductivity in CLM4.5 through a parameterization modification, it is found that shallow layer soil moisture increases compared to the initial value; and (2) The numerical values of unsaturated hydraulic conductivities in the model are obviously larger than experimental values. By substituting the Brooks-Corey soil water characteristic curve into the Mualem model, the value of unsaturated hydraulic conductivity is modified; (3) By using the modified value, it is found that the attenuating magnitude of simulated soil moisture caused by each rainfall event is reduced. The soil moisture variation in shallow layers (5, 10 and 20 cm) could be better displayed.

  • Features on N/P ratio of plants with different functional groups between two types of steppe in semi-arid area
  • YueDan Zhao,XingDong He,Lei Chen,XinFeng Ding,MengQi Li,PingYi Xu,YuBao Gao
  • DOI: 10.3724/SP.J.1226.2019.00371.
  • 2019, Vol.11 (5): 371–381 Abstract ( 96) HTML ( 8) PDF (1124 KB) ( 150 )
  • The differences in nitrogen/phosphorus (N/P) ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics. Based on the functional groups of plant growth type, carbon metabolism pathway, root type and phylogenetic type, we analyzed characteristics of leaf N/P ratios of 77 species in Sanggendalai (typical grassland zone) of Zhenglan Banner, Inner Mongolia, China and 91 species in the Habahu National Nature Reserve (desertified grassland zone) in Yanchi County of Ningxia, China. The results show that the N/P ratio (16.91) of C3 plants in the desertified steppe was significantly larger than that (12.72) in the typical steppe, but there was no significant difference between the N/P ratios of C4 plants in the two zones. There was no significant difference in N/P ratios between C3 plants and C4 plants in the same zone. Similarly, the N/P ratio (16.60) of dicotyledons in desertified steppe were significantly higher than that (12.98) in typical steppe, while differences in N/P ratios between monocotyledonous plants of the two zones was not significant, and there existed no significant difference in N/P ratios between dicotyledonous and monocotyledonous plants in the same zone. The N/P ratio had significant difference between gramineous and non-gramineous plants in the typical steppe but not in the desertified steppe, but there existed no significant difference in N/P ratios among different root types of perennial herbaceous plants in the same type of steppe or between two types of steppe. Thus, different features on the N/P ratios of C3 plants and dicotyledonous plants between typical steppe and desertified steppe may lead to different growth status of plants, and the N/P ratio stoichiometric of the same plant functional group may be a foundation of the changes of a plant community.

  • Qualitative and quantitative phytochemical analysis of selected mosses with different alcoholic solvents
  • Kehinde O. Olasoji,Amos M. Makinde,Bolajoko A. Akinpelu,Musibau O. Isa
  • DOI: 10.3724/SP.J.1226.2019.00382.
  • 2019, Vol.11 (5): 382–388 Abstract ( 211) HTML ( 1715) PDF (670 KB) ( 302 )
  • This study was conducted to investigate the qualitative and quantitative phytochemical content of the crude extracts of Archidium ohioense, Pelekium gratum, and Hyophila involuta with different alcoholic solvents (ethanol, methanol, Seaman's Schnapps, fresh oil-palm wine, and fresh Raffia-palm wine). The mosses were collected from their natural populations on the central campus of the Obafemi Awolowo University, Ile-Ife, Nigeria. The yield of the extracts was weighed for all the solvents, and the qualitative and quantitative evaluations of the extracts were carried out using standard methods. The results of phytochemical analysis of the crude extracts from the mosses showed the presence of saponins, cardiac glycosides, triterpenes, alkaloids, flavonoids, and steroids. The quantitative phytochemical analysis of the crude extracts showed that ethanolic extracts of Hyophila involuta had the highest flavonoid content (288.37±0.10 mg RE/g), and Raffia-palm-wine extracts of Hyophila involuta had the highest saponin content (224.70±0.02 mg/g), while the methanolic extract of Archidium ohioense had the highest cardiac glycosides content (63.71±0.14 mg/g), and the Raffia-palm wine extract of Hyophila involuta had the highest alkaloids content (102.50±0.12 mg/g). Raffia- and oil-palm wines were observed to be the most effective solvents for all the mosses studied, followed by Seaman's Schnapp, while methanol and ethanol were less effective. The study concluded that the extracts of the mosses studied contain pharmacologically active constituents that can be used for therapeutic purposes.

  • Analysis of structural characteristics and spatial distribution of the national intangible cultural heritage in China and its policy implications
  • BaiCui Xu,JingHu Pan
  • DOI: 10.3724/SP.J.1226.2019.00389.
  • 2019, Vol.11 (5): 389–406 Abstract ( 188) HTML ( 822) PDF (4506 KB) ( 244 )
  • Based on an investigation of four published batches listing 3,140 national intangible cultural heritage (ICH) projects in China and using GIS and some quantitative analysis methods, the spatial structure was investigated and the characteristics and distribution discussed. The distribution of ICHs in China is agglomerative and spatially dependent. From the view of ICH type, each type is distributed in different places, for different reasons, with history being the most important one we found. Nationwide, high-density cores are located in the Beijing-Tianjin-Hebei region and the Yangtze River Delta region. High densities of ICH are concentrated in flat, water-rich regions where broad-leaved forests dominate plains and low mountain areas—areas that have fertile soil, pleasant weather, a long history of culture, ethnic agglomeration, and development. This paper suggests that development of the ICH should be based on discovering unknown items, to break the existing pattern of strong cohesion and high density, and to seek a balanced development of the whole.