气候变化对雅鲁藏布江拉萨裂腹鱼生长的影响

Effects of climate change on growth of Schizothorax waltoni in Yarlung Zangbo River

  • 摘要: 为揭示裂腹鱼类生长对过往气候变化的长期响应规律,基于硬组织年代学法研究重建了拉萨裂腹鱼 (Schizothorax waltoni) 50年的历史生长序列,并利用混合效应模型探索了生长对过往气候变化的响应。结果显示,年轮计数法和交叉定年法估算的拉萨裂腹鱼年龄的平均百分比误差 (IAPE) 分别为5.13%和0%,随着年龄的增长2种方法估算年龄的差异性逐渐增大。估算的同步生长系数均值为0.406,实测轮纹宽度随年龄的增长呈显著减小趋势。构建的生长混合效应模型对拉萨裂腹鱼生长的解释率高达91.7%,其中,内在因子和气候因子的解释率总计为80.1%。拉萨裂腹鱼生长展现出个体和年际变异性,其生长稳态在20世纪90年代发生了转变。气温、北极涛动 (AO)、厄尔尼诺南方涛动 (ENSO) 和印度洋偶极子 (IOD) 均与拉萨裂腹鱼生长呈负的线性关系,且对其生长的影响存在空间和滞后效应。其中,印度洋偶极子是关键气候因子,该因子估算的参数值为 −0.061 8。建议后续研究将性成熟因子和其他环境因子纳入模型构建,并综合考虑时间、空间和物种等多维尺度,从而更系统、深入地揭示裂腹鱼类生长对多重环境变化的响应规律。

     

    Abstract: To elucidate long-term response patterns of Schizothoracine fishes growth to past climate change, we reconstructed a 50-year historical growth chronology of Schizothorax waltoni by using hard tissue dendrochronology and explored its growth response to past climate variability through mixed-effects models. The results demonstrate that the index of average percentual error in age estimation between annual ring counting and cross-dating methods was 5.13% and 0%, respectively, with the discrepancy between the two methods increasing with age. The mean synchrony index of growth chronology was 0.406, and a significant decreasing trend in measured increment width was observed with advancing age. The constructed growth mixed-effects model explained 91.7% of the growth variation in S. waltoni, with intrinsic factors and climatic factors collectively accounting for 80.1% of the explanatory power. The growth of S. waltoni exhibited both individual and interannual variability, with a growth regime shift occurring in the 1990s. Temperature, Arctic Oscillation (AO), El Niño-Southern Oscillation (ENSO), and Indian Ocean Dipole (IOD) all showed negative linear relationships with fish growth, demonstrating spatial and lag effects on growth patterns. Notably, IOD emerged as the key climatic driver, with an estimated parameter value of −0.061 8. Future studies should incorporate sexual maturity and additional environmental factors into model construction while considering temporal scales, spatial scales, and species-specific characteristics to achieve a more comprehensive understanding of schizothoracine fishes' growth responses to multifaceted environmental changes.

     

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