西尔根气河水系浮游植物功能群时空变化特征

Spatiotemporal Variation Characteristics of Phytoplankton Functional Groups in the Xiergenqi River System

摘要: 为探究寒温带河流浮游植物功能群的时空变化特征，本研究于2024年春季(6月)、夏季(8月)和秋季(9月)在黑龙江省双河国家级自然保护区内的西尔根气河水系(包括大西尔根气河、小西尔根气河及西尔根气河)设置9个采样点，开展浮游植物样本的采集、鉴定及功能群划分。研究结果显示，浮游植物功能群共划分为23个，分别为A、B、C、D、E、F、G、H1、J、K、LO、MP、M、N、P、S1、TB、W1、W2、X1、X2、X3、Y。依据优势度指数(Y ≥ 0.02)三个季节共筛选出10种优势功能群，其演替趋势为：春季(C、J、LO、MP、P、TB、X1)→夏季(C、D、J、MP、P、TB、W1、W2)→秋季(B、C、D、H1、N、P、S1、X1、X2、Y)；三条河流共有的优势功能群为D、LO、MP、P、TB。NMDS分析表明浮游植物优势功能群在季节间存在差异，而在空间上未表现出明显差异。西尔根气河水系浮游植物优势功能群的季节演替特征显著，空间变化特征不明显，反映了季节变化的驱动作用。

Abstract: To investigate the spatiotemporal variation characteristics of phytoplankton functional groups in a cold-temperate river, this study established nine sampling sites in the Xiergenqi River system (including the Daxiergenqi River, Xiaoxiergenqi River, and Xiergenqi River) within the Shuanghe National Nature Reserve in Heilongjiang Province during spring (June), summer (August), and autumn (September) of 2024. Phytoplankton samples were collected, identified, and classified into functional groups. The results showed that the phytoplankton were divided into 23 functional groups: A, B, C, D, E, F, G, H1, J, K, LO, MP, M, N, P, S1, TB, W1, W2, X1, X2, X3, and Y. Based on the dominance index (Y ≥ 0.02), a total of 10 dominant functional groups were identified across the three seasons, with a succession trend as follows: spring (C, J, LO, MP, P, TB, X1) → summer (C, D, J, MP, P, TB, W1, W2) → autumn (B, C, D, H1, N, P, S1, X1, X2, Y). The dominant functional groups common to all three rivers were D, LO, MP, P, and TB. NMDS analysis indicated differences in the dominant phytoplankton functional groups among seasons, but no significant spatial differences were observed. The seasonal succession of dominant phytoplankton functional groups in the Xiergenqi River system was significant, whereas spatial variation was not pronounced, reflecting the driving role of seasonal changes.