Author/Editor     Zhu, Liping; Wang, Jungo; Brancelj, Anton
Title     A study on environmental changes based upon cladoceran assemblages from the core sediments in Chen Co, southern Tibet
Type     članek
Source     Chinese Sci Bull
Vol. and No.     Letnik 50, št. 13
Publication year     2005
Volume     str. 1386-94
Language     eng
Abstract     A consecutive sediment core (CC2) was drilled in Chen Co (lake) of southern Tibet using a PISTON sampler in 1998 AD. Cladoceran remains including their species, amount richness and ecological features are analyzed for the top 117 cm sections of the core, upon which 5 cladoceran assemblages are distinguished. CLO is an assemblage without any cladocera in the depth between 117 105 cm. CLl assemblage (depths between 101 77 cm, ca. 1407 1533 AD) possesses total 9 cladoceran species that appear in the core, and performs the greatest richness in the whole sequence. This assemblage reflected that there was plenty of exotic cold water and organic debrises inputing to the sedimentary site under the warmer conditions. The lake was wide and shallow that satisfied the big hydrophyte living. Cladoceran species and richnesses of CL2 assemblage (depths between 77 29 cm, ca. 1533 1831 AD) perform much more decreasing than those of CLl. There was only less Chydorus sphaericus which was acclimatized to wide environmental ranges. This implied that the sedimentary environment is so execrable that most of cladoceran lost their living abilities. Compared with CL1 assemblage, CL3 assemblage (depths between 29 10 cm, ca. 1831 1941 AD) possesses nearly the same dominant species but lower richnesses. Especially, the cladoceran preferring organic debris also decrease in their amounts. This meant that the surface vegetation in the drainage basin was still poor though the environment turned to be better. (Abstract truncated at 2000 characters)
Descriptors     FRESH WATER
GEOLOGIC SEDIMENTS
CRUSTACEA
ECOSYSTEM
LEAD RADIOISOTOPES
CESIUM RADIOISOTOPES
TIBET