新疆饼干衣属地衣分类学研究

该研究以采自新疆的100余份饼干衣属(Rinodina)地衣标本为研究材料,通过形态解剖特征观察、地衣化学成分分析以及分子生物学鉴定方法鉴定出9个种,包括2个中国新记录种——阿富汗饼干衣(Rinodina afghanica)和古氏饼干衣(Rinodina guzzinii),7个常见种分别是:包氏饼干衣(R.bohlinii)、毕氏饼干衣(R.bischoffii)、代谢饼干衣(R.metaboliza)、密果饼干衣(R.pycnocarpa)、特雷氏饼干衣(R.trevisanii)、甘肃饼干衣(R.straussii)和地生饼干衣(R.terrestris)。并提供了新疆饼干衣属地衣的分种检索表、每个物种的详细描述、新记录种的特征图片以及系统发育分析。     

Soil carbon stock and its changes in northern China's grasslands from 1980s to 2000s

Climate warming is likely to accelerate the decomposition of soil organic carbon (SOC) which may lead to an increase of carbon release from soils, and thus provide a positive feedback to climate change. However, SOC dynamics in grassland ecosystems over the past two decades remains controversial. In this study, we estimated the magnitude of SOC stock in northern China's grasslands using 981 soil profiles surveyed from 327 sites across the northern part of the country during 2001–2005. We also examined the changes of SOC stock by comparing current measurements with historical records of 275 soil profiles derived from China's National Soil Inventory during the 1980s. Our results showed that, SOC stock in the upper 30 cm in northern China's grasslands was estimated to be 10.5 Pg C (1 Pg=10¹⁵ g), with an average density (carbon stock per area) of 5.3 kg C m^?2. SOC density (SOCD) did not show significant association with mean annual temperature, but was positively correlated with mean annual precipitation. SOCD increased with soil moisture and reached a plateau when soil moisture was above 30%. Site‐level comparison indicated that grassland SOC stock did not change significantly over the past two decades, with a change of 0.08 kg C m^?2, ranging from ?0.30 to 0.46 kg C m^?2 at 95% confidence interval. Transect‐scale comparison confirmed that grassland SOC stock remained relatively constant from 1980s to 2000s, suggesting that soils in northern China's grasslands have been carbon neutral over the last 20 years.     

新疆阿尔泰山曲尾藓科2个中国新记录种

阿尔泰山是欧亚大陆最为宏伟的山脉之一,其中段的西南坡坐落于中国新疆境内,众多具温带性质的藓类植物分布于此。作者在对阿尔泰山进行苔藓植物区系调查过程中,发现了分布于阿尔泰山的喀纳斯自然保护区及布尔津县禾木乡的2个藓类植物中国新记录种——隶属曲尾藓科的短叶曲尾藓[Dicranum brevifolium(Lindb.)Lindb.]和卷叶小曲尾藓[Dicranella crispa(Hedw.)Schimp.]。由地理分布可知,短叶曲尾藓和卷叶小曲尾藓在中国皆为稀有种类。     

新疆粉衣科地衣分类学研究

该研究以采自新疆的100余份粉衣科地衣标本为研究材料,通过形态解剖学、地衣化学以及分子生物学的方法鉴定出6个种和1个变种,分别为中央黑瘤衣(Buellia centralis)、丽黑瘤衣(B.elegans)、蒙古黑瘤衣(B.mongolica)、鳞饼衣(Dimelaena oreina)、鳞饼衣白磷变种(D.oreina var.exalbescens)、海登氏多瘤胞(Diplotomma hedinii)和绿色四孢黑瘤衣(Tetramelas chloroleucus),其中丽黑瘤衣、蒙古黑瘤衣和绿色四孢黑瘤衣为新疆新增粉衣科地衣新记录,至此新疆粉衣科地衣共有6属13种1变种;并提供了新疆粉衣科地衣的分种检索表、物种描述、系统发育分析以及形态解剖结构照片。     

Some Effects of Amo-1618 on Growth, Peroxidase and α-Amylase Which Cannot Be Easily Explained by Inhibition of Gibberellin Biosynthesis

Growth and peroxidase activity of roots and stems of lentil seedlings were compared after treatment with Amo-1618, alone or in combination with gibberellic acid (GA) at varying concentrations. The peroxidase enhancement in Amo-1618 treated stems could not be attributed to a decrease in the gibberellin content since GA alone had no effect on this enzyme. In other experiments, AMO, at low concentrations, was able to induce α-amylase production in barley aleurone layers; the lag period needed for this induction, was longer than for GA. These facts seem to indicate that some growth retardants might act at least in some cases by mechanisms other than inhibition of gibberellin biosynthesis and reversal of GA action.     

土壤中铁锰的形态分布及其有效性研究

以乌鲁木齐雅马里克山的土壤为研究对象,采用Tessier连续提取法对土壤铁、锰各种化学形态进行浸提.研究了土壤中有效铁、锰和土壤的理化性质与土壤铁、锰形态之间的关系,及对铁、锰在土壤中存在形态的影响;并通过盆栽试验对铁、锰的植物有效性进行了分析.结果表明,土壤铁主要以残渣态为主,占全铁的92.3%,其它形态含量均小于全量的8%.土壤锰主要是以铁锰氧化态和残渣态为主,分别占全锰的49%和41.6%,其它形态含量均小于全量的10%.用二级出水灌溉处理可增加铁、锰的有效性,原污水灌溉不利于铁、锰的供应,土壤缺铁、锰的现象可通过施加一定量的铁盐和锰盐而得以改善.相关分析还表明,土壤的理化性质与铁锰形态之间有一定的相关性.供试土壤的pH值、CaCO3含量、有机质及阳离子交换态等对土壤铁、锰的有效性影响较大.逐步回归分析表明,铁的氧化物结合态对植物最为有效,锰的有机结合态对植物有效性贡献最大.     

鹞落坪自然保护区地面生地衣多样性及群落数量特征

在鹞落坪保护区设置样方,调查样方内地面生地衣种类和生境指标,探讨森林地面生地衣的分布模式和群落特征。对地衣群落进行了因子分析和排序;应用2×2联表的Fisher精确检验和Spearman秩相关系数进行了种间关联分析。因子分析表明随海拔上升,种类趋于减少,优势种的数目和盖度之间存在显著的正相关（P=0.034）,样方湿度和样方生境类型存在极其显著的正相关（P=0.001）。根据组平均分析结果并综合生境特征,将保护区地面生地衣划分为5个群丛类型。Fisher精确检验表明仙人掌绵腹衣Anzia opuntiella与红心黑蜈蚣衣Phaeophyscia erythrocardia等10个种对呈极显著正相关,4个种对呈显著正相关,无显著负相关种对出现。各个地衣种之间的竞争很小。