Cai Jiaqing, Bennie Jonathan, Gaston Kevin J
Environment and Sustainability Institute, University of Exeter, Cornwall, Penryn, TR10 9FE, UK.
Centre for Geography and Environmental Science, University of Exeter, Cornwall, Penryn, TR10 9FE, UK.
Oecologia. 2025 Jun 27;207(7):114. doi: 10.1007/s00442-025-05750-z.
Artificial light at night (ALAN) has been spreading rapidly globally, disrupting animal physiology, behaviour and associated ecosystem processes. However, impacts on soil-dwelling animals that are nocturnally active aboveground remain underexplored. Here, we examined these for the earthworm Lumbricus terrestris L., an ecosystem engineer that frequently surfaces at night. We recorded four types of L. terrestris nighttime surface behaviour, including overall surface activity, and three finer categories: risk exploration before surfacing, foraging and over-surface exploration. One experiment (controlled-temperature-room-based) tested these behavioural responses to seven ALAN levels, whilst another (field-based) investigated whether behavioural responses can consequently affect litter removal and soil respiration. In the controlled-temperature room, compared to darkness, L. terrestris significantly decreased their overall nighttime foraging at ALAN levels of 10 lx and above, with these negative ALAN effect sizes increasing with light intensity. With more risk exploration before surfacing, L. terrestris still showed greatly reduced foraging activity at the 10 lx ALAN level in the field. However, such altered behaviour did not cause clear patterns in either litter removal or soil respiration. Our results confirm that 10 lx ALAN (or potentially lower) is effective in disrupting L. terrestris nighttime surface behaviour, but this may have limited impacts on short-term C cycling.
夜间人造光（ALAN）在全球范围内迅速蔓延，扰乱了动物的生理、行为及相关的生态系统过程。然而，对夜间在地面活动的土壤动物的影响仍未得到充分研究。在此，我们以夜间频繁出现在地面的生态系统工程师——蚯蚓（Lumbricus terrestris L.）为对象进行了研究。我们记录了蚯蚓夜间在地面的四种行为类型，包括总体地面活动，以及三个更细致的类别：出现在地面之前的风险探索、觅食和地面上的额外探索。一项实验（基于控温室）测试了蚯蚓对七种ALAN水平的行为反应，而另一项实验（基于野外）则研究了这些行为反应是否会进而影响凋落物清除和土壤呼吸。在控温室中，与黑暗环境相比，当ALAN水平达到10勒克斯及以上时，蚯蚓显著减少了夜间的总体觅食活动，且这些负面的ALAN效应大小随光照强度增加。尽管在出现在地面之前有更多的风险探索，但在野外10勒克斯的ALAN水平下，蚯蚓的觅食活动仍大幅减少。然而，这种行为改变并未在凋落物清除或土壤呼吸方面导致明显的模式。我们的结果证实，10勒克斯的ALAN（或可能更低）能有效扰乱蚯蚓夜间的地面行为，但这可能对短期碳循环的影响有限。
