[Identification of the critical coastal conservation areas with ecological significance based on Pb stable isotope signatures analysis]. / 基于Pbç¨³å®šåŒä½ç´ åˆ†æžçš„æµ·å²¸å¸¦ç”Ÿæ€ä¿æŠ¤å ³é”®åŒºåŸŸè¯†åˆ«.

Pb stable isotope signatures analysis can be used to identify its sources precisely and the spatial transportation process to achieve precise management of target areas. In this study, 12 surface (0-10 cm) soil samples (3-5 replications for each site) were collected on the Yancheng coast. Pb isotopes (206Pb, 207Pb and 208Pb) and Pb contents were analyzed by inductively coupled plasma mass spectrometry. Results showed that the soil Pb contents were as high as 1.7 times of the background Pb content value. Referencing the national criteria of GB 15618-2008, the study area was polluted by Pb to a relatively serious extent. The analysis indicated that main Pb sources of the area were local, including Sheyang Power Plant, Shuangdeng Paper Mill Sewage Plant, and Huafeng industrial area near Wanggang. Based on the normalized difference vegetation index (NDVI) and distance analysis, we figured out the key patterns of Yancheng coast to cope with the press sources.

Differential contribution of frugivorous birds to dispersal patterns of the endangered Chinese yew (Taxus chinensis).

The contribution of forest generalists and specialists to the dispersal pattern of tree species is not well understood. Specialists are considered low-quality dispersers because their dispersal distance is often short. However, disregard for seed deposition site may result in underestimation of the dispersal quality of specialists. The present study estimated the contribution of generalist and specialist species to the dispersal patterns of the endangered Chinese yew (Taxus chinensis) in a subtropical patchy forest in Southeast China. A relatively diverse assemblage of frugivorous birds visited T. chinensis source trees, and specialist Hypsipetes leucocephalus and generalist Urocissa erythrorhyncha were by far the highest-quantity dispersers. Considering dispersal effectiveness, the quantity aspect of effectiveness differed between the specialist assemblage and generalist assemblage; the contribution of specialists to the quantity part of effectiveness was significantly higher than that of generalists despite the relatively low diversity of specialists. After foraging, both specialist H. leucocephalus and generalist U. erythrorhyncha significantly contributed to the number of seedlings, and their contributions to seedling recruitment did not differ with regard to quality. Our results highlight the ability of T. chinensis to recruit an effective disperser assemblage in patchy habitats, thus increasing its persistence in this disturbed habitat.

[Explore the spatial and temporal patterns of water pollution in the Yincungang canal of the Lake Taihu basin, China].

Two high-density snap-shot samplings were conducted along the Yincungang canal, one important tributary of the Lake Tai, in April (low flow period) and June (high flow period) of 2010. Geostatistical analysis based on the river network distance was used to analyze the spatial and temporal patterns of the pollutant concentrations along the canal with an emphasis on chemical oxygen demand (COD) and total nitrogen (TN). Study results have indicated: (1) COD and TN concentrations display distinctly different spatial and temporal patterns between the low and high flow periods. COD concentration in June is lower than that in April, while TN concentration has the contrary trend. (2) COD load is relatively constant during the period between the two monitoring periods. The spatial correlation structure of COD is exponential for both April and June, and the change of COD concentration is mainly influenced by hydrological conditions. (3) Nitrogen load from agriculture increased significantly during the period between the two monitoring periods. Large amount of chaotic fertilizing by individual farmers has led to the loss of the spatial correlation among the observed TN concentrations. Hence, changes of TN concentration in June are under the dual influence of agricultural fertilizing and hydrological conditions. In the view of the complex hydrological conditions and serious water pollution in the Lake Taihu region, geostatistical analysis is potentially a useful tool for studying the characteristics of pollutant distribution and making predictions in the region.