盐碱池塘围隔生态系统的悬浮物结构及有机碳库储量

The Seston Structure and the Storage of Organic Carbon Pools in Enclosures of Saline-alkaline Ponds

1 998年 4～ 7月对高青盐碱池塘单养鲢和罗非鱼围隔生态系统颗粒悬浮物构成和各有机碳库储量及动态进行了研究。结果表明 ,浮游生物的干重 (PZ)占总颗粒悬浮物干物质 (TS)的 4.2 6%～ 2 5 .97% ,平均 1 2 %。各围隔浮游植物干重(DWP)平均值变化范围为 0 .1 6～ 0 .70 mg/L,有鱼围隔均比无鱼围隔的大。浮游动物干重 (DWZ)平均值变化范围为0 .3 2～ 2 .81 mg/L,养鲢围隔中最小 ,小于无鱼对照围隔 ,养罗非鱼围隔明显高于养鲢围隔。颗粒悬浮物的灰分含量平均值为 42 .3 8%。溶解有机碳 (DOC)、颗粒有机碳 (POC)库储量平均值分别为 5 .40± 1 .61 mg C/L和 1 .96± 0 .96mg/L。各处理围隔间颗粒有机物的 C/N比的平均值比较接近 ,总平均值为 6.97± 0 .2 4。 TOC、DOC和 POC比例为 1∶ 0 .73∶0 .2 7。浮游生物碳和腐质颗粒碳占 POC的比例的平均值分别为 3 4.65 %和 65 .3 5 %。腐质颗粒碳、浮游动物碳与浮游植物碳的比例为 9.2 9∶ 3 .71∶ 1。浮游生物碳中浮游动物碳占 78.8% ,浮游植物碳占 2 1 .2 %。浮游动物碳比浮游植物碳高 ,这可能是内陆盐水的通性。盐碱池塘围隔生态系统颗粒有机碳 (POC,mg C/L)与浮游植物叶绿素 a(Chla,μg/L)和悬浮颗粒有机物 (SO,mg/L)之间存在显著的正相关关系 。

The particulate seston structure and the storage and dynamics of various organic carbon pools in enclosures with silver carp ( Hypophthalmichthys molitrix) and Nile Tilapia ( Orecohromis niloticus ) in saline\|alkaline ponds were estimated, in order to provide information for increasing fish production and management scientifically water quality of this type of water bodies. The experiments were carried out in Daluhu Fish Farm (Latitude 37°17′N, Longitude 117°55′E), Gaoqing County, Shandong Province from April to July in 1998. The pond of which placed enclosure is 0 10 ha in area, and water depth was 1 4m. During the experiment, water temperature varied from 18 5 to 32 0℃, and conductivity ranged from 1000 to 2400 μs/cm. Total alkalinity ranged from 3 02 to 5 64 mmol/L. The experimental enclosures were the land\|based enclosures in ponds. The enclosures were 20m\+2 (4m×5m) in area, 2 0 m in height (1 4m in water depth), and was made of plastic\|coated polyethylene woven cloth with a frame composed of wood and bamboo poles. The results indicated that the ratios of dry weight of plankton ( PZ ) to dry weight of total seston ( TS ) were 4 26%~25 97%, and the average value was 12%. The mean dry weight of phytoplankton ( DWP ) in various enclosures ranged from 0 16 to 0 70 mg/L, the DWP of enclosures with fishes was higher than that of enclosure without fishes. The mean dry weight of zooplankton ( DWZ ) in various enclosures ranged from 0 32~2 81 mg/L, the DWZ of enclosures with silver carp was lowest, less than control enclosures without fishes, and significantly lower than that of enclosures with Tilapia. The mean ash contents of seston was 42 38%. The mean storage of dissolve organic carbon (DOC) and particulate organic carbon (POC) were 5 40±1 61 and 1 96±0 96 mgC/L, respectively. POC content of three enclosures with Tilapia (2 38±1 20 mgC/L) was higher than that of three enclosures with silver carp (1 99±0 78 mgC/L)( p >0 5). The POC content of control enclosures without fish was 1 28±0 21 mgC/L. The POC content of enclosures with fishes higher than that of enclosure without fishes ( p <0 001). The mean C/N ratio in various groups was similar, total mean C/N ratio was 6 97±0 24. The ratio of total organic carbon (TOC), DOC and POC was 1∶0 73∶0 27. The mean ratio of the planktonic carbon and detritus particular carbon to the POC was 34 65% and 65 35%, respectively. The ratio of detritus particulate carbon, zooplankton carbon and phytoplankton carbon was 9 29∶3 71∶1. The ratio of the zooplankton carbon and phytoplankton carbon to the planktonic carbon was 78 8% and 21 2%, respectively. Zooplankton carbon contents exceeded phytoplankton carbon by an average of 3 71 times, this is possible the common characteristic of inland saline waters. The POC (mgC/L) of enclosures in saline\|alkaline ponds have passive correlated significantly to the Chl\|a (μg/L) and suspended particulate organic matter(SO, mg/L), the correlation function were: POC=1 00+0 10 Chl\|a and POC=1 26+0 08 SO.