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Catchment erosion and trophic status changes over the past century as recorded in sediments from Wudalianchi Lake, the northernmost volcanic lake in China.
- Source :
-
Quaternary International . Dec2012, Vol. 282, p163-170. 8p. - Publication Year :
- 2012
-
Abstract
- In June 2009, two short sedimentary cores, wdlc-3 and wdlc-5, were collected from Wudalianchi Lake (48°40′ N ∼ 48°47′ N, 126°06′ E ∼ 126°15′ E) in the north central of Heilongjiang Province, northeastern China, using a gravity corer. The catchment erosion and trophic status changes were studied by an interpretation of the variations of multi-proxies, including organic matter (loss on ignition (LOI 550°C ) and total organic carbon (TOC)), total phosphorus (TP), total nitrogen (TN), magnetic susceptibilities, organic carbon isotope (δ 13 C org ) and grain size. Sediment accumulation rates (SARs) and ages were determined using a composited model of the 210 Pb or 137 Cs methods, respectively. The results are as follows: 1) the average sediment rate was 0.28 g cm −2 y −1 (0.59 cm y −1 ) in wdlc-3 and 0.25 g cm −2 y −1 (0.55 cm y −1 ) in wdlc-5 over the past 100 years. The interaction of the large-scale land reclamation and rainfall were related to high sediment accumulation rates before the 1980s; after the 1980s, however, the changes of precipitation were most likely the main influencing factor on SARs. 2) The δ 13 C org values ranged from −26.78 to −25.79‰ in wdlc-3 and −25.82 to −21.95‰ in wdlc-5. The TOC and TN showed an upcore increasing tendency, and TN, TOC and TP showed a dramatic increase since the 1980s. Based on the multi-proxies, the sediments recorded the change of the aquatic plant community from macrophyte-dominant to algae-dominant in the third lake and to macrophyte and algae coexistence in the fifth lake, also reflecting the changes of trophic status over the past 100 years. 3) Large-scale reclamation was the main factor impact the lake environment before the 1980s; after the 1980s, enhanced agricultural activities such as extensive use of fertilizers and the discharge of domestic waste water resulted in dramatic changes in the lake environment. [ABSTRACT FROM AUTHOR]
- Subjects :
- *WATERSHEDS
*LAKE sediments
*CARBON compounds
*CRATER lakes
*LAKES
Subjects
Details
- Language :
- English
- ISSN :
- 10406182
- Volume :
- 282
- Database :
- Academic Search Index
- Journal :
- Quaternary International
- Publication Type :
- Academic Journal
- Accession number :
- 102786635
- Full Text :
- https://doi.org/10.1016/j.quaint.2012.05.012