02363nas a2200229   4500008004100000245010400041210006900145260001200214300001200226490000700238520157200245653002501817653002301842653004501865653002501910653002201935100001501957700001501972700001301987700001602000856011702016       2009                        eng d00aPreliminary study on community characteristics of Isoetes orientalis at different succession stages0 aPreliminary study on community characteristics of Isoetes orient  c2009///  a22 - 270 v183 aComparative analyses of species composition, community ecological quantitative characteristics, species diversity and propogation mode of Isoëtes orientalis H. Liu et Q. F. Wang communities at different succession stages were conducted by the method of space-replacing-time. The results show that at early succession stage, the community has the lowest diversity ( species richness, Shannon-Wiener index, Pielou evenness index and β diversity index) , and the abundance, coverage, important value and niche breadth of I. orientalis population are the highest, which makes I. orientalis the dominant species. At middle succession stage, the abundance, coverage, important value and niche breadth of I. orientalis population all decrease, while the community shows the highest species diversity, which makes the climax community of I, orientalis. At late succession stage, the abundance, coverage, important value and niche breadth of I. orientalis population fall to the lowest levels, and perennial herbs such as Miscanthus sinensis Anderss. and Zizania latifolia ( Griseb.) Turcz. ex Stapf become dominant species. Along with the succession process, the number of species adopting asexual/vegetative propogation increases and the main propogation strategy of the community changes from sexual propogation to asexual/vegetative propogation. It is suggested that in the process of succession, the changes of species composition, species diversity, propogation strategy of species and mesophytic habitat may be the major reason to decline of I. orientalis population.10aCommunity succession10aEndangered species10aIsoëtes orientalis H. Liu et Q. F. Wang10aPropogation strategy10aSpecies diversity1 aZhu, S.-C.1 aZhu, W.-J.1 aChen, X.1 aTang, J.-J.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-67651120104&partnerID=40&md5=abd46b2e9745329f95cfe24ddc9298c302518nas a2200229   4500008004100000245011800041210006900159260001200228300001200240490000700252520173000259653002401989653004502013653002602058653000902084653001902093100001502112700001302127700001602140700001502156856011702171       2010                        eng d00aAnalyses on soil nutritional status and water pH value in natural habitat of endangered plant Isoëtes orientalis0 aAnalyses on soil nutritional status and water pH value in natura  c2010///  a75 - 780 v193 aThe content of main nutritional components in soil of natural habitat of two plots (Shupowan and Xiaolanhu in Songyang of Zhejiang Province) of Isoëtes orientalis H. Liu et Q. F. Wang was comparatively analyzed, and the pH value of water in plot of Shupowan was determined. On this basis, the factors of soil and water led to I. orientalis endangered were discussed. The results show that contents of organic matter, total nitrogen, available phosphorus, available potassium and total iron ions (including Fe 3+ and Fe 2+) in soil of Shupowan are 102. 7 g · kg -1, 3.1 g · kg -1, 18.1 μg · g -1, 15.0 μg · g -1 and 221. 6 μg · g -1, respectively, and those in soil of Xiaolanhu are 122. 8 g · kg -1, 4. 8 g · kg -1, 13. 7 μg · g -1, 7. 1 μg · g -1 and 240.0μg · g -1, respectively. The contents of organic matter, total nitrogen and available potassium in soil of Xiaolanhu are significantly or very significantly higher than those of Shupowan, while the content differences of available phosphorus and total iron ions are not significant between two plots. But the available potassium content in soil of two plots is very low, while the total iron ion content is rich. The water pH values in upper, middle and down streams of Shupowan are pH 6. 35, pH 6.53 and pH 6.49, respectively, showing approximately neutral. It is suggested that the soil type in the two natural plots is the type which the contents of organic matter, total nitrogen, available phosphorus and total iron ions are rich, and the available potassium content is low. And extreme lack of available potassium in soil and water neutralization are probably the important environmental factors to limit development of I. orientalis population.10aAvailable potassium10aIsoëtes orientalis H. Liu et Q. F. Wang10aNutritional component10aSoil10aWater pH value1 aZhu, W.-J.1 aChen, X.1 aTang, J.-J.1 aZhu, S.-C.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-77954341144&partnerID=40&md5=3478cbd245851411b8c190d3d302d043