RESUMEN
The contents and stable S isotope ratio (δS) values of total S, organic S, SO-S, and total reduced inorganic S (TRS) in typical limestone soil and yellow soil were analyzed in this study to examine the general distributions of S forms and their δS values in soils in karst areas of southwest China. Under a similar level of acid deposition, the vertical profiles of the S forms and their δS values differed in limesto\ne soil and yellow soil, indicating the different geochemical responses of these soils to acid deposition. The deposited SO was retained as organic S in both soils. The depletion in S of TRS relative to SO and the parallel increasing δS values of TRS and SO indicate a bacterial reduction process of sulfate in both soils. The different extents of C-bonded S mineralization and organic sulfate transport explain the different vertical profiles of total S and organic S contents in both soils. Sulfate adsorption in limestone soil was negligible because of high pH values. Sulfate adsorption in yellow soil was another important S retention process in addition to biological S retention to form organic S and TRS because of low pH values. The effect of acid deposition on yellow soil appeared more serious because of the accumulation and leaching of deposited SO, which can result in soil acidification and accelerate the loss of basic cations from yellow soil. However, compared with yellow soil, limestone soil released more S into rivers by organic S mineralization after a large decrease in annual S deposition rate.
RESUMEN
Two new species of the genus Saigona Matsumura, 1910, S.baiseensis Zheng & Chen sp. nov. and S.maculata Zheng & Chen sp. nov., from China (Guanxi) are described and illustrated. A revised identification key to the 16 species of Saigona is provided. 15 species of the genus are known from China only.
RESUMEN
The first complete mitochondrial genome of a dictyopharid planthopper, Orthopagus splendens (Germar, 1830) (Hemiptera: Fulgoroidea: Dictyopharidae) is sequenced. The 15,349 bp long complete mitogenome contains 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and 1 A + T-rich region with an arrangement identical to that observed in most insect mitogenomes (GenBankNo. MW441850). All PCGs start with ATN, and end with TAN or single T (nad1, nad5, and atp6). A phylogenetic analysis places O. splendens as sister to Fulgoridae confirming a sister relationship between Dictyopharidae and Fulgoridae.
RESUMEN
Two new species Miasa dichotoma Zheng & Chen, sp. n. and M. trifoliusa Zheng & Chen, sp. n. from China are described and illustrated. A key of identification to all species of the genus is provided.
RESUMEN
Two new species of the genus Tenguna Matsumura, 1910, Tenguna kuankuoshuiensissp. n., Tenguna plurijugasp. n., collected from China, are described and illustrated, photographs of the new species are provided together. A key is given to identify all the known species of Tenguna.
RESUMEN
By measuring the foliar δ13C values of common local plant species grown in different soil types in Wangjiazhai catchments, a typical karst desertification area in Qingzhen City, Central Guizhou, we studied the impact of soil type and rocky desertification grade on the foliar δ13C values. The results showed that the foliar δ13C values were more negative in yellow soil area than those in black calcareous area and there was no obvious difference in foliar δ13C values between these two soil types. The distribution interval of foliar δ13C values in yellow soil area was narrower than those in black calcareous area and the variation coefficient of foliar δ13C values in yellow soil area were smaller than those in black calcareous area. With increasing degree of karst rocky desertification, the foliar δ13C values of plant community in black calcareous area increased, whereas those in yellow soil area first increased and then decreased. The result of multiple comparison showed that the difference in foliar δ13C values of plant community among rocky desertification grade was not obvious in yellow soil area, but it was obvious in black calcareous area. Correlation analysis between the foliar δ13C values of plant species and the main environmental factors indicated that slope and soil thickness were the main factors which affected the foliar δ13C values of plants in yellow soil area and soil water contant was the main factor in black calcareous area. The impact of soil on the foliar δ13C values was realized by adjusting the soil moisture in study area.