生物多样性 ›› 2024, Vol. 32 ›› Issue (11): 24276.  DOI: 10.17520/biods.2024276  cstr: 32101.14.biods.2024276

• 生物入侵专题 • 上一篇    下一篇

桥头堡效应中气候生态位差异的缩小促进了红火蚁的入侵

杜聪聪1,2,3(), 冯学宇1,2,3, 陈志林1,2,3,*()   

  1. 1.广西师范大学珍稀濒危动植物生态与环境保护教育部重点实验室, 广西桂林 541006
    2.广西珍稀濒危动物生态学重点实验室, 广西桂林 541006
    3.广西师范大学生命科学学院, 广西桂林 541006
  • 收稿日期:2024-06-30 接受日期:2024-11-08 出版日期:2024-11-20 发布日期:2024-12-10
  • 通讯作者: E-mail: chenzhilin35@163.com
  • 基金资助:
    国家自然科学基金(32100345);国家自然科学基金(32360127);广西科技基地和人才专项(AD21220162)

The reducing of climate niche differences in the bridgehead effect promotes the invasion of Solenopsis invicta

Congcong Du1,2,3(), Xueyu Feng1,2,3, Zhilin Chen1,2,3,*()   

  1. 1. Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education), Guangxi Normal University, Guilin, Guangxi 541006, China
    2. Guangxi Key Laboratory of Rare & Endangered Animal Ecology, Guilin, Guangxi 541006, China
    3. College of Life Science, Guangxi Normal University, Guilin, Guangxi 541006, China
  • Received:2024-06-30 Accepted:2024-11-08 Online:2024-11-20 Published:2024-12-10
  • Contact: E-mail: chenzhilin35@163.com
  • Supported by:
    National Natural Science Foundation of China(32100345);National Natural Science Foundation of China(32360127);Guangxi Science and Technology Base and Talent Special Project(AD21220162)

摘要:

生物入侵是入侵生物学、生物地理学、生态学等学科研究的重要内容。为了预测和预防新的入侵, 了解入侵过程的驱动因素至关重要。与原产地相比, 入侵地物种的生态位是否发生漂移的争论一直存在。入侵物种的扩散过程十分复杂, 除了直接由原产地转移至入侵地, 还能由初次入侵地转移至其他入侵地, 这一现象被称为桥头堡效应, 普遍存在于入侵物种的扩散过程中。因此, 在评估入侵物种的生物地理学、洲际流动和气候生态位变化时, 考虑桥头堡效应至关重要。因此, 本研究以红火蚁(Solenopsis invicta)为研究对象, 探究其原产地(南美洲)、桥头堡地(美国)和二次入侵地(中国)两两之间的气候生态位重叠和漂移。 结果表明: 红火蚁南美洲种群和美国种群之间的气候生态位重叠程度较低(Schoener’s D = 0.06, Hellinger’s I = 0.20), 生态位稳定性较高(93.78%), 扩张程度较低(6.22%)。红火蚁南美洲种群和中国种群之间的气候生态位重叠程度也很低(Schoener’s D = 0.01, Hellinger’s I = 0.05), 生态位稳定性较高(97.60%), 扩张程度较低(2.40%)。但是, 在考虑桥头堡效应的情况下, 桥头堡地(美国)和二次入侵地(中国)种群之间的气候生态位重叠程度却较高(Schoener’s D = 0.34, Hellinger’s I = 0.51), 生态位稳定性较低(28.08%), 扩张程度较高(71.92%)。由此可见: 当前以美国为枢纽的贸易全球化进程在打破了长距离地理空间的限制之后, 桥头堡地种群入侵至中国后不仅能够快速适应相似的气候环境, 还在此基础上发生了明显的生态位漂移, 极可能与桥头堡地种群的适应能力密切相关, 暗示了桥头堡效应在促进红火蚁全球化入侵过程中的重要性。

关键词: 气候生态位, 红火蚁, 生物入侵, 桥头堡效应, 生态位漂移

Abstract

Aims: Biological invasions are a vital component of research in invasion biology, biogeography, ecology and other disciplines. Better understanding drivers of the invasion process is essential to predict and prevent future invasions. Controversy persists over whether the niche of invaded range has shifted compared to native range. The diffusion process of invasive species is complex. In addition to directly transferring from a native to an invaded range, species can transfer from the initial invaded range to other invaded ranges. This phenomenon is known as the bridgehead effect and is commonly present in the diffusion process of invasive species. Therefore, the bridgehead effect must be considered when assessing the biogeography, intercontinental mobility, and climatic niche changes of invasive species. Our study compared the climatic niche progression of populations in native, bridgehead, and secondary invaded ranges of Solenopsis invicta. We uncovered the ecological mechanisms underlying the successful invasion of S. invicta to provide new insights into the niche conservatism hypothesis.

Methods: We used global distribution data and environmental variables of S. invicta obtained from http://www.moa.gov.cn. Based on pre-analysis results of the ecological niche model, we selected the environmental variables with a greater contribution to the distribution of the species. A two-by-two comparative analysis of the climatic niche of populations in native range (South America), bridgehead range (United States), and secondary invaded range (China) was done by using the “ecospat” package. The test of equivalency and similarity of the niche was performed to assess the degree of niche overlap. Additionally, the environmental space occupied by the climatic niche of S. invicta was categorized into stability, unfilling, and expansion. Further, the size of the expansion was used to assess the extent of niche displacement in the invaded range.

Results: The climatic niche overlap between South American and United States populations of S. invicta was relatively low (Schoener’s D = 0.06, Hellinger’s I = 0.20), with high niche stability (93.78%) and low expansion (6.22%). The climatic niche overlap between South American and Chinese populations of S. invicta was also low (Schoener’s D = 0.01, Hellinger’s I = 0.05), with high niche stability (97.60%) and low expansion (2.40%). However, considering the bridgehead effect, the climatic niche overlap between the bridgehead range (United States) and the secondary invaded range (China) populations was relatively high (Schoener’s D = 0.34, Hellinger’s I = 0.51), with low niche stability (28.08%) and high expansion (71.92%). The degree of ecological niche conservancy was highest, and the degree of deviation lowest, between the native range and secondary invaded range, which was consistent with the result of ecological niche overlap between the two regions. Although the ecological niche conservancy degree between the native range and bridgehead range was relatively high and the degree of deviation low, the ecological niche conservancy degree between the bridgehead range and secondary invasion interval was extremely low. There was also a significant deviation in the ecological niche. During the invasion process, S. invicta first spread to adjacent United States, which served as a center for further invasion, leading to subsequent invasions into regions such as China. This process is known as the bridgehead effect. The degree of climate niche overlap between South America and the United States and China was relatively low, while the degree of climate niche overlap between the United States and China was relatively high. Further, the current process of trade globalization centered on the United States has broken the limitations of long-distance geographic space and led to the rapid adaptation of S. invicta from the United States to China, resulting in ecological niche shift.

Conclusion: The current trade globalization process, with United States as the center, is breaking down long-distance geospatial limitations. Thus, the invasion of populations from this bridgehead range to China has rapidly adapted to similar climatic environments. On this basis, the adaptability of populations in the bridgehead range implies the importance of the bridgehead effect in facilitating the invasion of S. invicta globally.

Key words: climatic niche, Solenopsis invicta, biological invasion, bridgehead effect, niche shift