作 者：
杨钙仁;于婧睿;苏晓琳;王冠;陈友文;陈桂金
关键词：
黑水;发生规律;水质特征;鱼类毒害;桉树人工林
摘 要：
为了解桉树(Eucalyptus)人工林采伐迹地黑水的发生规律及其对鱼类的影响,通过气象观测、黑水和受黑水污染鱼塘水体水质分析以及黑水污染致死鱼样受害症状调查,研究了黑水发生的气象环境、水质特征及其对鱼类的致害成因。研究结果表明:1黑水仅发生于新采伐迹地,新鲜采伐剩余物与高温高湿多雨天气是其发生的物质前提和气象条件,多爆发于夏季;2黑水颜色为墨黑,其色度(837~1153度)、化学需氧量(COD)(116~151 mg·L~(-1))、总氮(TN)含量(3.5~6.3 mg·L~(-1))分别为对照林溪水的16.4~52.9(P<0.01)、3.3~5.7(P<0.01)和3.4~4.6(P<0.01)倍,p H值则比对照低0.2~0.8(P<0.05);3受黑水污染的鱼塘水体色度、COD、pH值、TN和铵态氮(NH_4~+-N)含量分别升高286.4度(P<0.01)、24.5 mg·L~(-1)(P<0.01)、0.6(P<0.01)、0.66 mg·L~(-1)(P<0.01)和1.32 mg·L~(-1)(P<0.01),总磷(TP)(P<0.01)和硝态氮(NO_3~--N)(P<0.05)含量则降低;受黑水污染的鱼塘水溶解氧(DO)含量下降至1.04 mg·L~(-1),鱼类急性死亡的直接原因主要为缺氧;4选择在秋冬季和夏季无雨天气下采伐、减小同期连片采伐面积可防止黑水发生或减缓其危害程度。
译 名：
Occurrence of Black Water in Cut-over Areas of Eucalyptus Plantation and Its Effect on Fish
作 者：
YANG Gai-ren;YU Jing-rui;SU Xiao-lin;WANG Guan;CHEN You-wen;CHEN Gui-jin;Forestry College of Guangxi University;Gaofeng State-owned Forest Farm of Guangxi;
关键词：
Black water;;Occurrence patterns;;Water quality;;Harm to fish;;Eucalyptus plantation
摘 要：
For better understanding the occurrence rules of black liquids( black water) in cut-over areas of Eucalyptus plantation,the occurrence meteorological conditions,water quality,and harmful effect on the fishes of black water were explored by a combination of meteorological monitoring,black water and contaminated fishpond water quality analysis,and symptom examination in dead fish caused by black water contamination. Results show that:( i) Black water only occurs in new cut-over areas with fresh logging residues as the premise and high-temperature high-humidity rainy weather as the climate condition; this phenomenon mainly occurs in summer,but rarely in winter or spring.(ii) Black water is characterized by a jet-black color,with the colority of 837~(-1)153 o,chemical oxygen demand(COD) of 116~(-1)51 mg·L~(-1),total nitrogen(TN) level of 3. 5-6. 3 mg·L~(-1),which are respectively 16. 4-52. 9(P < 0. 01),3. 3-5. 7(P < 0. 01),and3. 4-4. 6( P < 0. 01) times those of normal stream water in a control forest( un-logged Eucalyptus plantation of the same / similar age); p H value of black water is 0. 2-0. 8 lower than that of normal stream( P < 0. 05).( iii) Compared to uncontaminated fishpond water,black water-contaminated fishpond water displays significant increases( P < 0. 05 or 0. 01) in the colority( by 286. 4o),COD( by 24. 5 mg·L~(-1)),pH value(by 0. 6),TN and ammonium-N(NH_4~+-N) levels(0. 66 and 1. 32 mg·L~(-1)),with significant decreases in total phosphorous( TP)( P < 0. 01) and nitrate-N level( NO_3~--N)( P < 0. 05). Black water contamination of fishpond water leads to rapid decreases in dissolved oxygen content to 1. 04 mg·L~(-1)in a short period,and lack of oxygen is a direct cause for death of fish.( iv) Logging of Eucalyptus plantation in fall and winter or non-rainy days in summer and reduction of concomitant cutting area help to prevent the occurrence of black water and mitigate its harmful effects.
