Sockman KW, All Weather Data, Raw.xlsx

Widespread declines in the abundance of insects portend ill-fated futures for their host ecosystems, all of which require their services to function. For many such reports, human activities have directly and significantly altered the land or water of these ecosystems, raising questions how insects in less impacted environments are faring. I quantified the abundance of flying insects during 15 seasons over a 20-yr span on a relatively unscathed, subalpine meadow in Colorado, where weather data have been recorded for 38 yr. I discovered that insect abundance declined an average of 6.6% annually, yielding a 72.4% decline over 20 yr. Information theoretic analysis of 59 combinations of weather-related factors best supported the association between abundance and an interaction between date and mean daily temperature the prior summer. Specifically, a seasonal increase in abundance tended to a seasonal decline as the previous summer's mean daily temperature increased, resulting in a long-term decline as mean daily temperature-minima during summer have risen here 0.8°C per decade. In this relatively pristine area, insects are declining precipitously, auguring poorly for this and possibly other such ecosystems that depend on the roles insects play in food webs, pollination, pest control, and nutrient cycling.

昆虫种群丰度的普遍下降，预示着其宿主生态系统将迎来黯淡前景——所有这类生态系统的正常运转均依赖昆虫提供的生态服务。针对多数相关研究而言，人类活动已直接且显著地改变了对应生态系统的陆地或水环境，这引发了学界的核心疑问：受干扰程度较低的环境中，昆虫种群的生存状况究竟如何？本研究选取科罗拉多州一处相对未受干扰的亚高山草甸（subalpine meadow）作为研究区域，该区域已有38年的连续气象观测记录；研究者在20年的周期内开展了15个观测季节的飞行昆虫种群丰度量化测定工作。研究结果显示，昆虫丰度年均下降6.6%，20年累计降幅达72.4%。通过对59种气象相关因子组合开展信息论分析，最优模型证实昆虫丰度与调查日期和前一年夏季日均温的交互效应存在显著关联。具体而言，随着前一年夏季日均温升高，昆虫丰度的季节性增长趋势会逐渐转为季节性下降；而该区域夏季日均最低气温正以每10年0.8℃的速率上升，最终导致昆虫丰度出现长期下降。在这片相对原始的研究区域中，昆虫种群正急剧衰减，这预示着依赖昆虫在食物网、传粉、害虫防治及养分循环中发挥关键功能的本区域及其他类似生态系统，均将面临严峻的发展前景。