2008 DEC 30 - (VerticalNews.com) -- "Holocene environmental change in Mongolia is reconstructed on the basis of recently published paleoclimate records, including lake levels, pollen assemblages, and eolian sediment records. These data indicate that the early Holocene of Mongolia is characterized by increasing temperature and humidity," researchers in Lanzhou, People's Republic of China report.

  "Paleosol development, high lake-stands, and a more southward distribution of forest-steppe environments suggest the early-mid Holocene was humid. The mid-Holocene however is characterized by enhanced aridity, even though the onset and termination of the dry interval differs from place to place," wrote C.B. An and colleagues, Lanzhou University ...read more

  2008 DEC 30 - (VerticalNews.com) -- According to a study from Taipei, Taiwan, "We propose and test a theory describing the onset and growth of tributary-dammed lakes. Using a diffusion equation constrained by backwater effects, we show how tributary sediment influx can cause either a cuspate river aggradation or the formation of a lake upstream of the tributary junction."

  "This lake expands up valley and drowns previous deposits to leave a downstream-facing lake bed of inclination milder than the angle of stability. We obtain exact similarity solutions for such river and lake bed profiles and validate them quantitatively using laboratory experiments," wrote J.P.C. Hsu and colleagues, National Taiwan University ...read more

  2008 DEC 22 - (VerticalNews.com) -- "Net ecosystem productivity (NEP) was continuously measured using the eddy covariance (EC) technique from 2003 to 2005 at three forest sites of ChinaFLUX. The forests include Changbaishan temperate mixed forest (CBS), Qianyanzhou subtropical coniferous plantation (QYZ), and Dinghushan subtropical evergreen broad-leaved forest (DHS)," scientists in Beijing, People's Republic of China report.

  "They span wide ranges of temperature and precipitation and are influenced by the eastern Asian monsoon climate to varying extent. In this study, we estimated ecosystem respiration (RE) and gross ecosystem productivity (GEP). Comparison of ecosystem carbon exchange among the three forests shows that RE was mainly determined by temperature, with the forest at CBS exhibiting the highest temperature sensitivity among the three ecosystems. The RE was highly dependent on GEP across the three forests, and the ratio of RE to GEP decreased along the North-South Transect of Eastern China (NSTEC) (i.e. from the CBS to the DHS), with an average of 0.77 +/- 0.06. Daily GEP was mainly influenced by temperature at CBS, whereas photosynthetic photon flux density was the dominant factor affecting the daily GEP at both QYZ and DHS. Temperature mainly determined the pattern of the interannual variations of ecosystem carbon exchange at CBS. However, water availability primarily controlled the interannual variations of ecosystem carbon exchange at QYZ. At DHS, NEP attained the highest values at the beginning of the dry seasons (autumn) rather than the rainy seasons (summer), probably because insufficient radiation and frequent fog during the rainy seasons hindered canopy photosynthesis. All the three forest ecosystems acted as a carbon sink from 2003 to 2005. The annual average values of NEP at CBS, QYZ, and DHS were 259 +/- 19, 354 +/- 34, and 434 +/- 66 g C m(-2) yr(-1), respectively. The slope of NEP that decreased with increasing latitude along the NSTEC was markedly different from that observed on the forest transect in the European continent," wrote G.R. Yu and colleagues ...read more