[Responses of ground-active arthropod community in Caragana shrub plantations to grazing management in desertified region.] / 干旱风沙区灌丛林地地面节肢动物群落对放牧管理的响应.

We investigated the community structure of ground-active arthropods as well as vegetation and soil properties in Caragana shrub plantations under grazing and exclosure management across spring, summer and autumn in Yanchi County of Ningxia in northern China. The aim of this study was to uncover the responses of ground-active arthropods in shrub plantations to grazing management in desertified regions. The results showed that: 1) plant height, soil fine sand content, and soil electrical conductivity were significantly lower, whereas soil bulk density and coarse sand were significantly higher in shrub plantations under grazing than exclosure. 2) There were 40 families from 13 orders captured. The dominant groups included Formicidae and Tenebrionidae families, which comprised 68.75% of the total individuals. There were four common groups occupying 20.82% of the total individuals. The remaining 34 groups were relatively rare, only accounting for 10.44% of the total. Across the three seasons, the composition of ground-active arthropod community was significantly different between grazing and exclosure, which indicates the sensitivity and adaptability of ground-active arthropods to environmental changes including grazing management and seasonal changes. 3) There was a significant effect of grazing on total abundance of ground-active arthropods in shrub plantations, with significantly higher values under grazing than under exclosure. There was no significant effect of grazing management on group richness and diversity of ground-active arthropods in shrub plantations. 4) There was a correlation of total abundance, evenness index and the Simpson index with plant abundance, vegetation height, soil moisture, soil pH and electrical conductivity. There was a significant correlation of the Shannon index with vegetation height, soil moisture and soil fine sand. Plant density, and soil pH, soil moisture and soil temperature were the key factors driving the structure of ground-active arthropod communities in shrub plantations under gra-zing management across seasons based on the partial RDA results. It was concluded that the variations of plant height, soil pH, soil moisture and soil temperature under grazing management could result in different ground-active arthropod taxon to changing habitats. The conservation effect of shrub on ground-active arthropod could reduce the negative impacts of grazing. Spring grazing could enhance ground-active arthropod abundances in shrub plantations. It was necessary to pay attention to prevention of insects which are caused by spring grazing in shrub plantations.

[Soil particle composition, fractal dimension and their effects on soil properties following sand-binding revegetation within straw checkerboard in Tengger Desert, China]. / è ¾æ ¼é‡Œæ²™æ¼ è‰æ–¹æ ¼å›ºæ²™æž—åœŸå£¤é¢—ç²’ç»„æˆã€åˆ†å½¢ç»´æ•°åŠå ¶å¯¹åœŸå£¤æ€§è´¨çš„å½±å“.

This study aims to elucidate the effects of soil particle composition and fractal dimension on soil physical and chemical properties following sand-binding revegetation within straw checkerboard in south-eastern Tengger Desert. Three afforested plantations in the year of 2016 (i.e., 1 year), 2013 (i.e., 4 years) and 1987 (i.e., 30 years) were selected as study sites, with the adjacent mobile sand land as control (CK). We measured soil particle composition, soil fractal dimension, and the changes of soil physical and chemical properties. The relationship between soil particle composition, soil fractal dimension, and soil properties was analyzed. The results showed that contents of soil particle with the size of both 100-250 µm and 250-500 µm were greater than that of 50-100 µm, ranging from 42.5% to 80.1% and from 12.5% to 42.2% relative to that ranging from 0.2% to 20.8%. Contents of soil particle with the size of <2 µm and 2-50 µm were remarka-bly lower than that of 100-250 µm, 250-500 µm and 50-100 µm, ranging from 0 to 1.3% and from 0 to 22.7%, respectively. However, contents of soil particle at the size of 500-1000 µm was the lowest occupying <0.3% of soil particle composition. Soil particle with the size of <2 µm and 2-50 µm were found in the 30-year sites only. Soil particle distribution at the size of 50-100 µm, 100-250 µm, and 250-500 µm followed the order of 30 a>1 a>4 a＞CK, 4 a>1 a>CK>30 a, and CK>1 a>4 a> 30a, respectively. Soil particle with the size of 500-1000 µm occupied little of soil particle composition, with no significant difference between each site. The fractal dimension of soil particles ranged from 0.54 to 2.59. There was significantly greater soil fractal dimension in 30 a in comparison to 4 a, 1 a and CK, with the intermediate values in 4 a and 1 a, and the lowest values in CK. There was a significantly positive correlation of fractal dimension of soil particles with soil particle content of clay, silt, very fine sand, and a significantly negative correlation of fractal dimension of soil particles with soil particle content of medium sand. Fractal dimension of soil particles was positively correlated with soil electrical conductivity, organic carbon, total nitrogen, and carbon-nitrogen ratio, but with no correlation with soil pH and soil water content. Soil particle content at the size of <2 µm, 2-50 µm, and 50-100 µm had a significant positive correlation with soil electrical conductivity, organic carbon, total nitrogen, and carbon-nitrogen ratio, whereas soil particle content at the size of 250-500 µm had a negative correlation with the former four soil indices and soil water content. In addition, there was a significant negative correlation of soil particle content at the size of 500-1000 µm with soil water content. It was concluded that the sand-binding reve-getation within straw checkerboard in Tengger Desert could facilitate the fine soil particles by ameli-orating stressful soil conditions. Long-term succession of revegetation on mobile sand land could enhance soil clay and silt content as well as soil fractal dimension, thus be beneficial for the improvement of soil physical and chemical properties and desertification control.

Two new coumarin glycosides from Peucedanum praeruptorum.

Two new coumarin glycosides, praerosides VI (1) and VII (2), were isolated from the roots of Peucedanum praeruptorum Dunn. Their structures were elucidated by chemical reaction and NMR spectroscopic methods.

[Studies on xanthones from herbs of Polygala telephioides].

OBJECTIVE: To study the chemical constituents from the whole plants of Polygala telephioides. METHOD: Compounds were isolated by repeated silica gel and Sephadex LH -20 column chromatography, and their structures were determined by spectral analysis and physicochemical properties. RESULT: Six xanthones were isolated from P. telephioides, and their structures were identified as 1, 3, 7-trihydroxyxanthone (1), 1, 7-dihydroxy-3-methoxyxanthone (2), 1, 3-dihydroxyxanthone (3), 1, 7-dihydroxyxanthone (4), 1-methoxy-2, 3-methylenedioxyxanthone (5) and 1, 7-dimethoxyxanthone (6). CONCLUSION: All the compounds were obtained from this plant for the first time.

New diterpenoids from Semiaquilegia adoxoides.

Two new ent-kaurane-type diterpenoids, E-semiaquilegin (1) and Z-semiaquilegin (2), together with eight known compounds (3-10) were isolated from the dried roots of Semiaquilegia adoxoides (DC.) Makino. The structures of compounds 1 and 2 were elucidated mainly by 2D NMR techniques including 1H-1H COSY, HSQC, HMBC, NOESY as 16alpha-hydroxy-ent-kaurane-17,20-di-(3,4-dihydroxy-E-cinnamoyl) ester and its (Z)-isomer.

Triterpene saponins from the leaves of Ilex kudingcha.

Nine new triterpene saponins, ilekudinosides K-S (1-9), and eight known triterpene saponins were isolated from the 70% ethanol extract of the leaves of Ilex kudingcha. The new saponins were characterized as 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl-alpha-kudinlactone (1), 3-O-beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl-beta-kudinlactone (2), 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl-gamma-kudinlactone (3), 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl-alpha-kudinlactone (4), 3-O-beta-D-glucopyranosyl(1-->2)-alpha-L-arabinopyranosyl-alpha-kudinlactone (5), 3-O-beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl-alpha-kudinlactone (6), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl-beta-kudinlactone (7), 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl-beta-kudinlactone (8), and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl-gamma-kudinlactone (9), respectively. The structures and stereochemistry of compounds 1-9 were elucidated by spectroscopic data interpretation and chemical degradation.

[Chemical and pharmacological advances of study on Lysimachia].

The progress in the research of the chemical components and pharmacological activities of Lysimachia was reviewed. Lysimachia mainly contain flavonoids, saponins and phenolic acids, and some of the plants have been used in the treatment of fever, ulcers, diarrhea and as analgesic or anti-inflammatory agents. The plants of genus Lysimachia are widespread in China, so it is a singificants work to study their chemical ingredients and pharmacological activities.