No correlation between the diversity and productivity of assemblages: evidence from the phytophage and predator assemblages in various cotton agroecosystems  

作　　者：GAO Feng MEN XingYuan GE Feng 

机构地区：[1]College of Agriculture and Biotechnology, China Agricultural University [2]State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences [3]Institute of Plant Protection, Shandong Academy of Agricultural Sciences

出　　处：《Science China(Life Sciences)》2014年第9期936-943,共8页中国科学（生命科学英文版）

基　　金：supported by the National Natural Science Foundation of China(31101491,31030012);National Key Technology R&D Program(2012BAD19B05)

摘　　要：Biodiversity research has shown that primary productivity increases with plant species number,especially in many experimental grassland systems.Here,we assessed the correlation between productivity and diversity of phytophages and natural enemy assemblages associated with planting date and intercropping in four cotton agroecosystems.Twenty-one pairs of data were used to determine Pearson correlations between species richness,total number of individuals,diversity indices and productivity for each assemblage every five days from 5 June to 15 September 2012.At the same trophic level,the productivity exhibited a significant positive correlation with species richness of the phytophage or predator assemblage.A significant correlation was found between productivity and total number of individuals in most cotton fields.However,no significant correlations were observed between productivity and diversity indices(including indices of energy flow diversity and numerical diversity)in most cotton fields for either the phytophage or the predator assemblages.Species richness of phytophage assemblage and total individual numbers were significantly correlated with primary productivity.Also,species richness of natural enemy assemblage and total number of individuals correlated with phytophage assemblage productivity.A negative but not significant correlation occurred between the indices of numerical diversity and energy flow diversity and lower trophic-level productivity in the cotton-phytophage and phytophage-predator assemblages for most intercropped cotton agroecosystems.Our results clearly showed that there were no correlations between diversity indices and productivity within the same or lower trophic levels within the phytophage and predator assemblages in cotton agroecosystems,and inter-cropped cotton fields had a stronger ability to support the natural enemy assemblage and potentially to reduce phytophages.Biodiversity research has shown that primary productivity increases with plant species number, especially in many experi- mental grassland systems. Here, we assessed the correlation between productivity and diversity of phytophages and natural enemy assemblages associated with planting date and intercropping in four cotton agroecosystems. Twenty-one pairs of data were used to determine Pearson correlations between species richness, total number of individuals, diversity indices and productivity for each assemblage every five days from 5 June to 15 September 2012. At the same trophic level, the productivity exhibited a significant positive correlation with species richness of the phytophage or predator assemblage. A significant cor- relation was found between productivity and total number of individuals in most cotton fields. However, no significant correla- tions were observed between productivity and diversity indices （including indices of energy flow diversity and numerical di- versity） in most cotton fields for either the phytophage or the predator assemblages. Species richness of phytophage assem- blage and total individual numbers were significantly correlated with primary productivity. Also, species richness of natural enemy assemblage and total number of individuals correlated with phytophage assemblage productivity. A negative but not significant correlation occurred between the indices of numerical diversity and energy flow diversity and lower trophic-level productivity in the cotton-phytophage and phytophage-predator assemblages for most intercropped cotton agroecosystems. Our results clearly showed that there were no correlations between diversity indices and productivity within the same or lower trophic levels within the phytophage and predator assemblages in cotton agroecosystems, and inter-cropped cotton fields had a stronger ability to support the natural enemy assemblage and potentially to reduce phytophages.

关 键 词：CORRELATION PRODUCTIVITY DIVERSITY cotton agroecosystem insect assemblage 

分 类 号：S562[农业科学—作物学] Q16[生物学—普通生物学]