Effect of climate on the growth of annual rings in the main roots of perennial forbs in an Inner Mongolian semi‐arid grassland,China

Question: Is there a pattern in growth of annual rings in roots of perennial forbs in relation to climate and climate extremes in grassland ecosystems? Location: Semi‐arid grassland in Duolun (42°27′N, 116°41′E, 1380 m a.s.l.), central Inner Mongolia, China. Methods: Main roots of three perennial species, Potentilla anserina L., Cymbaria dahurica L. and Lespedeza daurica Schindl., were sampled. Cross‐sections (10–15‐μm thick) were produced from the proximal end of sampled roots using a sledge microtome. Annual growth rings in the main roots were identified and measured by differentiating between earlywood and latewood in the secondary xylem. Relationships between annual growth rings and monthly mean temperature and total monthly precipitation were identified using correlation analysis. Differences in an annual ring width to the previous and following years were examined by calculating a distinctness score. Results: The three perennial forbs showed clearly demarcated annual growth rings in all individuals and the same fluctuation patterns. Their ring widths were generally positively correlated with precipitation from April to October (except for August) and with temperature from February to June (except June for L. daurica), September to October, and the annual mean. Strong deviations of annual ring widths from their neighbour rings were observed in 1998 and 2000. The trend of absolute distinctness scores (D_m) increased significantly from 1988 to 2003, indicating an increase in the frequency of annual ring width variation. Conclusions: Annual growth rings in the main roots of three perennial forb species can be used as an indicator of the influence of climate on below‐ground grassland growth. The change in below‐ground conditions and effects on the functioning of grassland should receive more attention in future studies.     

A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Bayan Mandahu,Inner Mongolia

Abstract: A new oviraptorid is described on the basis of a partial forelimb collected from the Upper Cretaceous redbeds of Bayan Mandahu, Inner Mongolia. Machairasaurus leptonychus, gen. et sp. nov. is diagnosed by slender, weakly curved manual unguals, reduced flexor tubercles, penultimate phalanges that are subequal in length to the preceding phalanges, and short, robust manual digits. Machairasaurus is found to be a member of the Ingeniinae, along with Ingenia yanshini, Heyuannia huangi, Conchoraptor gracilis, and Nemegtomaia barsboldi. Machairasaurus exhibits unusual proportions of the manus, suggesting that the manus was not primarily used to grasp prey. Instead, Machairasaurus and other oviraptorids are likely to have fed largely on plant material. The recognition of a previously unknown oviraptorid at Bayan Mandahu provides further evidence that the Bayan Mandahu dinosaur assemblage is distinct from that found at the Djadokhta Formation exposures at Bayn Dzak, Tugriken Shireh, and Ukhaa Tolgod. Given that these localities are separated by just a few hundred kilometres and represent similar palaeoenvironments, marked differences in the fauna suggest that the Bayan Mandahu Formation of Inner Mongolia is not coeval with the known Djadokhta localities in Mongolia.     

An Epidemiologic Study of Arsenic-Related Skin Disorders and Skin Cancer and the Consumption of Arsenic-Contaminated Well Waters in Huhhot,Inner Mongolia,China

Well-use histories were obtained and dermatological examinations were conducted for 3,179 of the 3,228 (98.5%) residents of 3 villages in Inner Mongolia with well water arsenic levels as high as 2,000 ppb (ug/L). Eight persons were found to have skin cancer, 172 had hyperkeratoses, 121 had dyspigmentation, 94 had both hyperkeratoses and dyspigmentation, and, strikingly, none had Blackfoot disease. All 8 subjects with skin cancer also had both hyperkeratoses and dyspigmentation. Arsenic levels were measured for 184 wells and individual well-use histories were obtained. Arsenic exposure histories were summarized as both highest arsenic concentration (highest exposure level for at least 1-year duration) and cumulative arsenic exposure (ppb-years). Sixty-nine percent of the participants had highest arsenic concentrations below 100 ppb; 71% had cumulative arsenic exposures below 2,000 ppb-years. Exposure-response analyses included frequency-weighted, simple linear regression, and most-likely estimate (hockey-stick) models. Skin cancer cases were only found for those with a highest arsenic concentration greater than 150 ppb, and those with exposure less than 150 ppb had a statistically significant deficit. A frequency-weighted model showed a threshold at 150 ppb, and a hockey-stick model showed a threshold at 122 ppb. Considerations of duration, age, latency, and misclassification did not appear to markedly affect the analysis. The non-malignant skin findings showed thresholds of 40–50 ppb in the hockey-stick models. Application of these analytic models to the data from other epidemiological studies of arsenic ingestion and malignant and non-malignant skin disorders can be used to examine patterns of arsenic carcinogenicity.     

Elytral polymorphism in spittlebugs: Philaenus spumarius (L.) from the Inner Hebrides

The frequencies of colour and pattern morphs of the elytra of Philaenus spumarius are similar on three of the Small Isles of the Inner Hebrides (Eigg, Canna and Muck); the population on the fourth island (Rhum: is somewhat distinct but is like that at sea level on the nearby mountainous mainland. These similarities and differences suggest that these morph frequencies are regulated by natural selection.     

内蒙褐蛉—新种及二中国新记录种(脉翅目:褐蛉科)

脉翅目(Neuroptera)褐蛉科(Hemerobiidae)的成虫和幼虫均为肉食性昆虫,主要捕食蚜、蚧及叶螨等重要害虫,在生物防治中有利用前途。我国的褐蛉区系很丰富,已知百余种,许多是我国特有的种类。内蒙古的褐蛉科尚缺乏系统调查研究,蒙古人民共和国的褐蛉则报道有16种(Makarkin,1984),仅有少数几种与内蒙是共同的,但值得参考。就我们所掌握的标本来看,内蒙古的褐蛉至少有17种,本文记述一新种和二中国新记录种,模式标本保存在北京农业大学昆虫标本室。