Time series methods for the analysis of soundscapes and other cyclical ecological data

Biodiversity monitoring has entered an era of ‘big data’, exemplified by a near-continuous collection of sounds, images, chemical and other signals from organisms in diverse ecosystems. Such data streams have the potential to help identify new threats, assess the effectiveness of conservation interventions, as well as generate new ecological insights. However, appropriate analytical methods are often still missing, particularly with respect to characterizing cyclical temporal patterns. Here, we present a framework for characterizing and analysing ecological responses that represent nonstationary, complex temporal patterns and demonstrate the value of using Fourier transforms to decorrelate continuous data points. In our example, we use a framework based on three approaches (spectral analysis, magnitude squared coherence, and principal component analysis) to characterize differences in tropical forest soundscapes within and across sites and seasons in Gabon. By reconstructing the underly..., We used acoustic data collected from eight sites in the Ogooué-Ivindo province of Gabon to demonstrate how time-series approaches can be leveraged to compare cyclical trends within and between groups of sites. All soundscape sampling occurred in closed, Gabonese rainforest with minimal habitat disturbance for at least twenty years. First, we sampled the soundscape in the rainy season at four sites within Ivindo National Park, between February 19th and March 2nd 2021 (referred to as the Ivindo sites). Second, we sampled the soundscape in the dry season at four sites near Massaha between July 17th and July 23rd 2021 (hereafter referred to as the Massaha sites, about 15km from the Ivindo sites). At the time of sampling, the Massaha sites were located within a logging concession but no logging activity had commenced and there was an ongoing petition for the area to be re-designated as a community conservation area. Additionally, we used one site from the Lope National Park. At each site, we..., , # Time series methods for the analysis of soundscapes and other cyclical ecological data [https://doi.org/10.5061/dryad.xpnvx0kn6](https://doi.org/10.5061/dryad.xpnvx0kn6) Example dataset used for demonstrating the methods in \"Times Series Methods for the Analysis of Soundscapes and Other Cyclical Ecological Data\" Methods in Ecology and Evolution. This data represents soundscape data for eight tropical forest sites in Gabon collected between February and July 2021. See methods for more information. The soundscape is characterized using the soundscape index Power Minus Noise (PMN) for 256 frequency bins between 0-11 kHz for each minute of the day. PMN is a proxy for acoustic activity and provides a relatively simple index to demonstrate our methodological approach. ## Description of the data and file structure Column names: * Site: Site code (factor; 8 levels) * DatetimeFinal: Date time information (datatime object) * TotPMN: Values for characterizing the soundscape, Power minus noi...生物多样性监测已迈入“大数据”时代，典型特征为从多样生态系统中的生物体处近乎持续地采集声音、图像、化学信号及其他各类信号。此类数据流具备识别新兴威胁、评估保护干预措施成效，以及催生全新生态学认知的潜力。然而，适配此类数据的分析方法仍较为匮乏，尤其在刻画周期性时间模式方面。本文提出一套用于表征与分析非平稳复杂时间模式生态响应的框架，并演示了利用傅里叶变换（Fourier transform）对连续数据点进行去相关的应用价值。在示例研究中，我们采用基于三种分析方法（频谱分析、幅度平方相干性、主成分分析）的框架，对加蓬境内不同样地与季节间热带森林声景的差异进行表征。通过重构……（原文截断），我们使用了采自加蓬奥果韦-伊温多省8个样地的声学数据，以展示如何借助时间序列方法对比样地组内与组间的周期性趋势。 所有声景采样均在封闭的加蓬热带雨林中开展，该区域至少20年未发生显著的栖息地干扰。其一，我们于2021年2月19日至3月2日的雨季，在伊温多国家公园内的4个样地完成声景采样（下称伊温多样地）；其二，我们于2021年7月17日至7月23日的旱季，在马萨哈附近的4个样地开展采样（下称马萨哈样地，距伊温多样地约15公里）。采样期间，马萨哈样地位于伐木特许权区域内，但尚未有任何伐木活动启动，且该区域正处于申请重新划定为社区保护区的流程中。此外，我们还纳入了洛佩国家公园的1个样地。 在每个样地中，我们…… # 声景与其他周期性生态数据分析的时间序列方法 https://doi.org/10.5061/dryad.xpnvx0kn6 本数据集用于演示《声景与其他周期性生态数据分析的时间序列方法》（发表于*Methods in Ecology and Evolution*）中的分析方法。该数据集包含2021年2月至7月间，在加蓬8个热带森林样地采集的声景数据，详细信息请参见原文方法部分。声景通过声景指数功率减噪声（Power Minus Noise, PMN）进行表征：针对每日每分钟的采样，在0至11 kHz的频率范围内，于256个频率段上计算PMN值。PMN可作为声学活动的代理指标，为演示本文的方法论提供了简洁易用的量化标准。 ## 数据与文件结构说明 列名说明： * Site：样地代码（因子型变量，共8个水平） * DatetimeFinal：最终时间戳信息（日期时间对象） * TotPMN：用于表征声景的功率减噪声值（原文截断）