Complex and nonlinear climate-driven changes in freshwater insect communities over 42 years
Complex and nonlinear climate-driven changes in freshwater insect communities over 42 years
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DOI：
10.1111/cobi.13477
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发表时间：
2020-05-06
影响因子：
6.3
通讯作者：
Haase, Peter
中科院分区：
文献类型：
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作者：
Baranov, Viktor;Jourdan, Jonas;Haase, Peter
持续的生物多样性危机在广泛观察到的物种丰度和多样性的下降、群落结构的深刻变化和物种物候的变化中变得明显。昆虫是受影响最严重的群体之一，据记录，在过去25-30年里，一些陆地生态系统的昆虫数量减少了76%。确定潜在驱动因素是一个主要障碍，因为大多数生态系统同时受到多个应激源的影响，而且往往缺少对环境变量的现场测量。在我们的研究中，我们调查了一条属于德国最常见的溪流类型的源头溪流，该溪流位于一个自然保护区，除了气候变化之外，没有重大的人为影响。我们使用了现有的关于水生昆虫的最全面的长期量化数据集，其中包括每周测量物种级别的昆虫丰度、每日水温和溪流流量，以及42年期间(1969-2010年)其他物理化学变量的测量。总体而言，水温上升了1.88摄氏度，排放模式发生了显著变化。在这些变化的同时，昆虫丰富度下降了81.6%，但丰富度(+8.5%)、香农多样性(+22.7%)、均匀度(+22.4%)和年际周转率(+34%)都有所增加。此外，群落的营养结构和物候也发生了变化，羽化历期延长了15.2天，羽化高峰提前了13.4天。此外，我们观察到短期波动(
The ongoing biodiversity crisis becomes evident in the widely observed decline in abundance and diversity of species, profound changes in community structure, and shifts in species' phenology. Insects are among the most affected groups, with documented decreases in abundance up to 76% in the last 25-30 years in some terrestrial ecosystems. Identifying the underlying drivers is a major obstacle as most ecosystems are affected by multiple stressors simultaneously and in situ measurements of environmental variables are often missing. In our study, we investigated a headwater stream belonging to the most common stream type in Germany located in a nature reserve with no major anthropogenic impacts except climate change. We used the most comprehensive quantitative long-term data set on aquatic insects available, which includes weekly measurements of species-level insect abundance, daily water temperature and stream discharge as well as measurements of additional physicochemical variables for a 42-year period (1969-2010). Overall, water temperature increased by 1.88 degrees C and discharge patterns changed significantly. These changes were accompanied by an 81.6% decline in insect abundance, but an increase in richness (+8.5%), Shannon diversity (+22.7%), evenness (+22.4%), and interannual turnover (+34%). Moreover, the community's trophic structure and phenology changed: the duration of emergence increased by 15.2 days, whereas the peak of emergence moved 13.4 days earlier. Additionally, we observed short-term fluctuations (