不同海拔稻鲤综合种养梯田大型底栖动物群落结构特征

2019 年 5—8 月在云南省红河县哈尼梯田研究了不同海拔(570 m 和 1840 m)稻鲤综合种养梯田中大型底栖动物的群落结构。结果表明: (1)低海拔梯田内共发现大型底栖动物 25 种, 隶属 3 门 3 纲, 其中寡毛纲(Oligochaeta) 9 种, 昆虫纲(Insecta)16 种, 腹足纲(Gastropoda)1 种; 高海拔梯田内共发现大型底栖动物 24 种, 隶属 2 门 2 纲, 其中寡毛纲 3 种, 昆虫纲 21 种。寡毛纲和昆虫纲是高、低海拔梯田的主要大型底栖动物类群, 且种类组成差异显著 (P<0.05)。高、低海拔梯田均发现了摇蚊属(Chironomus)和长跗摇蚊属 (Tanytarsus)水稻害虫, 此外, 在低海拔梯田还发现了水稻害虫福寿螺(Pomacea canaliculata)。(2) 4 个月份 Jorgensen 指数值和 Jaccard 相似性指数值均说明不同海拔梯田中大型底栖动物群落结构存在较大差异。(3) 6 月和 7 月, 高、低海拔之间 Shannon-Wiener 多样性指数、 Pielou 均匀度指数、Margalef 丰富度指数在同一月份差异显著(P<0.05), 其余月份差异不显著(P>0.05)。(4)双因素方差分析表明, 月份和海拔对不同海拔梯田中的大型底栖动物密度影响显著(P<0.05), 月份对生物量影响显著 (P<0.05), 而海拔对其影响不显著(P>0.05), 月份和海拔间均存在交互作用(P<0.05)。研究表明, 月份和海拔是影响不同海拔哈尼梯田稻渔综合种养系统大型底栖动物群落结构的主要因素, 同时, 鲤的摄食压力也是导致大型底栖动物群落结构变化的重要因素, 鲤可以有效降低梯田中水稻害虫的生物量。

Characteristics of the macrobenthic community structure in integrated rice-carp farming terraces at different altitudes

The spectacular scenery of Hani terraces is an intangible world cultural heritage, but in recent years, the deterioration of these terraces, owing to the loss of young adult carp, is becoming increasingly severe, and they require urgent protection. In the present study, we investigated the ecological characteristics of the integrated rice-carp farming system in Hani terraced fields, which will provide a reference for optimizing the technical processes of integrated rice-carp farming systems in Hani terraced fields at different altitudes. From May to August 2019, a survey of the macrobenthos in integrated rice-carp farming terraces at different altitudes (570 m and 1840 m) was carried out at the Hani terraces in Honghe County, Yunnan Province. We investigated the differences in community composition, density, biomass, and diversity of macrobenthos of these Hani terraces. The Jargensen index and Jaccard similarity index were used to compare the similarity of macrobenthos community structures from high and low elevations, and the Shannon-Wiener, Pielou evenness, and Margalef richness indexes were used to evaluate biodiversity. Two-way analysis of variance (two-way ANOVA) was used to identify significant differences in the Shannon-Wiener, Pielou evenness, and Margalef richness indexes, density, and biomass of macrobenthos communities between high and low altitudes. The results showed that. (1) A total of 25 species of macrobenthos were found in low altitude terraces, which belonged to 3 phyla and 3 classes and included 9 species of Oligochaeta, 16 species of Insecta, and 1 species of Gastropoda. A total of 24 macrobenthic species were found in high altitude terraces, which belonged to 2 phyla and 2 classes and included 3 species of Oligochaeta and 21 species of Insecta. Oligochaeta and Insecta were the main macrobenthic groups in high and low altitude terraces, and the species compositions was significantly (P<0.05) different between the two altitudes. The rice pests Chironomus and Tanytarsus were found in terraces at both high and low altitudes. In addition, the rice pest Pomacea canaliculata was found at low altitudes. (2) The Jorgensen index and Jaccard similarity index values indicated differences in the macrobenthic community structure at the two altitudes during the 4 months that the study was conducted. (3) In June and July, the Shannon-Wiener diversity, Pielou evenness, and Margalef richness indexes between the high and low altitudes were significantly different in the same month (P<0.05), while the differences in the other months were not significant (P>0.05). (4) The two-way ANOVA showed that month and altitudes significantly (P<0.05) affected the density of macrobenthos at high and low altitudes and that month significantly (P<0.05) affected the biomass, but there was no significant difference between altitudes (P<0.05). There also was an interaction between density and biomass in month and altitude (P<0.05). The present study showed that altitude and month were the key factors affecting the macrobenthic community structure of the Hani terraced integrated rice-carp farming system at different altitudes. Concurrently, the feeding pressure of carp was also an important factor of differences in the macrobenthic community structure, which reduced the pest biomass in the Hani terraced integrated rice-carp farming system.