Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI, 53706, USA.
Nelson Institute for Environmental Studies, University of Wisconsin-Madison, 550 N Park Street, Madison, WI, 53706, USA.
Oecologia. 2024 Aug;205(3-4):597-612. doi: 10.1007/s00442-024-05598-9. Epub 2024 Jul 23.
Temperate woodlands are biodiverse natural communities threatened by land use change and fire suppression. Excluding historic disturbance regimes of periodic groundfires from woodlands causes degradation, resulting from changes in the plant community and subsequent biodiversity loss. Restoration, through prescribed fire and tree thinning, can reverse biodiversity losses, however, because the diversity of woodland species spans many taxa, efficiently quantifying biodiversity can be challenging. We assessed whether soundscapes in an eastern North American woodland reflect biodiversity changes during restoration measured in a concurrent multitrophic field study. In five restored and five degraded woodland sites in Wisconsin, USA, we sampled vegetation, measured arthropod biomass, conducted bird surveys, and recorded soundscapes for five days of every 15-day period from May to August 2022. We calculated two complementary acoustic indices: Soundscape Saturation, which focuses on all acoustically active species, and Acoustic Complexity Index (ACI), which was developed to study vocalizing birds. We used generalized additive models to predict both indices based on Julian date, time of day, and level of habitat degradation. We found that restored woodlands had higher arthropod biomass, and higher richness and abundance of breeding birds. Additionally, soundscapes in restored sites had higher mean Soundscape Saturation and higher mean ACI. Restored woodland acoustic indices exhibited greater magnitudes of daily and seasonal peaks. We conclude that woodland restoration results in higher soundscape saturation and complexity, due to greater richness and abundance of vocalizing animals. This bioacoustic signature of restoration offers a promising monitoring tool for efficiently documenting differences in woodland biodiversity.
温带林地是生物多样性丰富的自然群落，受到土地利用变化和火灾抑制的威胁。将林地中周期性地面火灾的历史干扰机制排除在外，会导致退化，这是由于植物群落的变化和随后的生物多样性丧失造成的。通过规定的火灾和树木疏伐进行恢复，可以逆转生物多样性的丧失，然而，由于林地物种的多样性跨越了许多分类群，因此有效地量化生物多样性可能具有挑战性。我们评估了在威斯康星州的五个恢复区和五个退化区的北美东部林地的声音景观是否反映了同期多营养层实地研究中测量的恢复过程中的生物多样性变化。在 2022 年 5 月至 8 月的每 15 天期间的五天内，我们在五个恢复区和五个退化区的林地中采样了植被，测量了节肢动物生物量，进行了鸟类调查，并记录了声音景观。我们计算了两个互补的声学指数：Soundscape Saturation，它专注于所有活跃的物种，以及 Acoustic Complexity Index（ACI），它是为研究发声鸟类而开发的。我们使用广义加性模型根据儒略日、一天中的时间和栖息地退化程度来预测这两个指数。我们发现，恢复后的林地有更高的节肢动物生物量，以及更高的繁殖鸟类的丰富度和数量。此外，恢复区的声音景观具有更高的平均 Soundscape Saturation 和更高的平均 ACI。恢复区林地的声学指数表现出更大的日变化和季节变化幅度。我们的结论是，由于发声动物的丰富度和数量增加，林地恢复导致声音景观饱和度和复杂性增加。这种恢复的生物声学特征为有效地记录林地生物多样性的差异提供了一种很有前途的监测工具。
