稻蟹共作系统对浮游甲壳动物群落的影响

在水稻的返青期、分蘖期、拔节期、扬花期和灌浆期,对稻蟹共作水环境的浮游甲壳动物群落进行研究。本实验设置了4个处理:单株/穴养蟹田(T1),双株/穴养蟹田(T2),四株/穴养蟹田(T4)和双株/穴不养蟹田(CK)。各处理均设3个平行。通过收集和分析实验田的浮游甲壳动物,经鉴定:枝角类有13种、桡足类有5种,共18种,其中4种为优势种。枝角类平均密度呈现先升高后下降趋势,分蘖期升至峰值,不养蟹田灌浆期下降至较低水平,养蟹田扬花期下降至较低水平随后上升但上升幅度不大,返青期和分蘖期各处理之间无显著差异(P0.05),而拔节期、扬花期和灌浆期养蟹田和不养蟹田之间差异极显著(P0.01)。桡足类平均密度总体呈上升趋势,返青期平均密度极低,仅为0.48 ind/L,平均生物量变化趋势与密度变化趋势基本相同。水稻的不同栽培模式对浮游甲壳动物有一定的影响。从生产的角度分析T1的栽培模式综合收益最大,因此,T1更有益于稻蟹共作生态系统。

The impact of rice-crab culture system on crustacean zooplankton community

During the tilling, tillering, jointing, flowering and filling stages, a study had been carried out on community of crustacean zooplankton in water environment of rice-crab culture model. This experiment include four treatments: a single seedling transplant of rice-crab culture(T1), a double seedling transplant of rice-crab culture(T2), a four seedling transplanting of rice-crab(T4) and a double seedling transplant of paddy without crab(CK). There were 3 parallel groups in each treatment. After being identified, 13 species of Cladocera and 5 species of Copepoda were found, and four species were dominant. Cladocera average density presents downward trend after rising first, rose to its highest in tillering stage, not crab filling paddy field down to a low level to filling stage. Crab filling paddy field in flowering down to lower levels,then rise but rose slightly. During the tilling and tillering stage no significant difference were observed between the groups (P > 0.05), while in jointing stage, flowering and filling period , no significant difference were observed between paddy fields (P<0.01); The copepods density in general is on the rise trend, reviving an average density is very low, is only 0. 48 ind/L-1 during tilling stage. Average trend of changes in biomass and the trend of density is basically the same. Different cultivation patterns of rice have a certain impact on crustacean zooplankton. From the perspective of the production model analysis, the single seedling transplant of rice-crab culture method may be more beneficial to rice-crab culture ecosystem.