Tu Bao Ngan, Khelidj Nora, Cerretti Pierfilippo, de Vere Natasha, Ferrari Andrea, Paone Francesco, Polidori Carlo, Schmid Jürg, Sommaggio Daniele, Losapio Gianalberto
Institute of Earth Surface Dynamics, University of Lausanne, 1015 Lausanne, Switzerland.
Department of Biosciences, University of Milan, 20133 Milan, Italy.
Alp Bot. 2024;134(2):171-182. doi: 10.1007/s00035-024-00309-9. Epub 2024 Apr 9.
Due to global warming, the worldwide retreat of glaciers is causing changes in species diversity, community composition, and species interactions. However, the impact of glacier retreat on interaction diversity and ecological networks remains poorly understood. An integrative understanding of network dynamics may inform conservation actions that support biodiversity and ecosystem functioning after glacier extinction. Here, we address how glacier retreat affects the frequency, diversity, and complexity of plant-pollinator interactions, both directly and indirectly through biodiversity change. We surveyed flower visitors (pollinators) and analyzed pollination networks across a gradient of 170 years of glacier retreat (Mont Miné glacier, Valais, Switzerland) which ranges from patchy grasslands to closed forests. We reported a strong impact of glacier retreat on both plant and pollinator communities. Notably, the diversity of plant-pollinator interactions was sharply affected by glacier retreat: interaction diversity increased few years after glacier retreat, but it ultimately decreased in late stages dominated by forests. In contrast, we found that plant-pollinator network complexity did not change with glacier retreat. Our results indicate that the development of plant-pollinator networks is a two-phases process. In the first phase, glacier retreat makes space to plant colonization. This initial increase in plant diversity drives the increase in pollinator and interaction diversity. The second phase is characterized by turnover as woody species encroaches and dominates the community, decreasing the diversity of plant species in ultimate instance. The local decrease of plant diversity leads to a local decrease in pollinator and interaction diversity. Slowing down woody encroachment and enhancing flower diversity, which is initially supported by the glacial landscape, may be key strategies for halting the erosion of ecological networks while increasing biodiversity and ecosystem functioning. Our research thus can help resolve the overarching question of how to conserve ecosystems once glaciers are extinct, pointing toward a composite role of both habitat structure and biological functions.
The online version contains supplementary material available at 10.1007/s00035-024-00309-9.
由于全球变暖，全球范围内冰川的消退正在导致物种多样性、群落组成和物种相互作用发生变化。然而，冰川消退对相互作用多样性和生态网络的影响仍知之甚少。对网络动态的综合理解可为支持冰川消失后生物多样性和生态系统功能的保护行动提供信息。在此，我们探讨冰川消退如何直接和通过生物多样性变化间接影响植物 - 传粉者相互作用的频率、多样性和复杂性。我们调查了访花者（传粉者），并分析了跨越170年冰川消退梯度（瑞士瓦莱州的米内山冰川）的传粉网络，该梯度范围从零散的草原到封闭的森林。我们报告了冰川消退对植物和传粉者群落都有强烈影响。值得注意的是，植物 - 传粉者相互作用的多样性受到冰川消退的显著影响：冰川消退几年后相互作用多样性增加，但在以森林为主的后期阶段最终下降。相比之下，我们发现植物 - 传粉者网络复杂性并未随冰川消退而变化。我们的结果表明，植物 - 传粉者网络的发展是一个两阶段过程。在第一阶段，冰川消退为植物定居腾出空间。植物多样性的这种初始增加推动了传粉者和相互作用多样性的增加。第二阶段的特征是更替，因为木本物种侵入并主导群落，最终导致植物物种多样性下降。植物多样性的局部下降导致传粉者和相互作用多样性的局部下降。减缓木本植物的侵入并增加花朵多样性，这最初由冰川景观所支持，可能是在增加生物多样性和生态系统功能的同时阻止生态网络侵蚀的关键策略。因此，我们的研究有助于解决冰川消失后如何保护生态系统这一总体问题，指出栖息地结构和生物功能的综合作用。
在线版本包含可在10.1007/s00035-024-00309-9获取的补充材料。
