Diel and seasonal variability of the forest soundscape in the Northeast China Tiger and Leopard National Park

doi:10.17520/biods.2022523

Abstract

Abstract:

Aims: Passive acoustic monitoring (PAM) and acoustic indices could provide an effective method for monitoring changes in forest soundscapes. However, annual dynamics of soundscapes remain poorly understood. We studied the diel, seasonal patterns, and shifts of the biotic component of the acoustic environment in the Northeast China Tiger and Leopard National Park.

Methods: We sampled recordings at 52 sites from June 2020 to June 2021 within the park. For each recording, we calculated the acoustic complexity index (ACI), acoustic diversity index (ADI), acoustic evenness index (AEI), bioacoustic index (BIO), normalized difference soundscape index (NDSI), acoustic entropy (H), and power spectral density (PSD) of each 1 kHz frequency bin within the 1-21 kHz frequency band. We divided a diel cycle into 4 phases (dawn, day, dusk, and night) according to the times the sun rose and set, and utilized generalized additive models (GAMs) to fit the curves of the diel and annual patterns of acoustic indices.

Results: The soundscapes demonstrated a marked distinction among all four phases, especially between night and other time periods. The soundscapes typically had more acoustic complexity, diversity, and biophony intensity during the daytime. However, night soundscapes showed more acoustic complexity throughout the summer season. In spring, the acoustic diversity index and bioacoustic index were higher at dawn due to intensive bird choruses. Acoustic complexity, diversity, and intensity of biophony demonstrate varied annual dynamics and peaked from May to October.

Conclusion: This study identified measurements that effectively summarize baseline soundscape attributes and prioritizes future opportunities for integrating non-acoustic and acoustic variables in research in order to inform area-specific management questions within the Northeast China Tiger and Leopard National Park.

Key words: ecoacoustics, forest soundscape, acoustic indices, Northeast China Tiger and Leopard National Park, biodiversity monitoring

Yifei Sun, Shizheng Wang, Jiawei Feng, Tianming Wang. Diel and seasonal variability of the forest soundscape in the Northeast China Tiger and Leopard National Park[J]. Biodiv Sci, 2023, 31(1): 22523.

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URL: https://www.biodiversity-science.net/EN/10.17520/biods.2022523

https://www.biodiversity-science.net/EN/Y2023/V31/I1/22523

Figures/Tables 12

References 70

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季节 Season	声学指数 Acoustic index	黎明 Dawn	白天 Day	黄昏 Dusk	夜晚 Night	χ2	P
春季 Spring	声音复杂度指数 ACI	908.99 ± 1.36^ab	912.70 ± 1.02^a	903.49 ± 0.89^b	895.68 ± 1.02^c	97.453	< 0.001^***
	声音多样性指数 ADI	1.38 ± 0.05^a	1.09 ± 0.04^b	0.93 ± 0.05^b	0.58 ± 0.05^c	80.140	< 0.001^***
	声音均匀度指数 AEI	0.84 ± 0.01^a	0.87 ± 0.01^b	0.88 ± 0.01^b	0.91 ± 0.01^c	78.321	< 0.001^***
	生物声学指数 BIO	12.79 ± 0.63^a	9.79 ± 0.45^ab	8.38 ± 0.40^b	5.89 ± 0.31^c	78.187	< 0.001^***
	标准化声景差异指数 NDSI	0.57 ± 0.03^a	0.39 ± 0.04^b	0.30 ± 0.04^b	0.22 ± 0.05^b	35.158	< 0.001^***
	声音熵指数 H	0.37 ± 0.01^a	0.38 ± 0.01^a	0.36 ± 0.01^ab	0.34 ± 0.01^b	15.694	< 0.001^***
夏季 Summer	声音复杂度指数 ACI	905.12 ± 1.25^a	898.86 ± 0.85^b	897.38 ± 0.61^b	908.09 ± 2.04^a	43.277	< 0.001^***
	声音多样性指数 ADI	1.61 ± 0.04^ab	1.78 ± 0.05^a	1.64 ± 0.05^a	1.40 ± 0.06^b	27.909	< 0.001^***
	声音均匀度指数 AEI	0.80 ± 0.01^a	0.75 ± 0.01^b	0.78 ± 0.01^ab	0.81 ± 0.01^a	25.499	< 0.001^***
	生物声学指数 BIO	13.27 ± 0.46^a	12.03 ± 0.36^a	11.64 ± 0.34^a	8.81 ± 0.28^b	79.432	< 0.001^***
	标准化声景差异指数 NDSI	0.58 ± 0.04^a	0.67 ± 0.03^a	0.63 ± 0.03^a	0.42 ± 0.05^b	20.688	< 0.001^***
	声音熵指数 H	0.42 ± 0.01^ab	0.51 ± 0.01^c	0.47 ± 0.01^ac	0.41 ± 0.01^b	32.107	< 0.001^***
秋季 Autumn	声音复杂度指数 ACI	902.78 ± 1.06^a	906.87 ± 1.02^b	901.52 ± 0.94^a	897.82 ± 0.86^c	47.306	< 0.001^***
	声音多样性指数 ADI	1.32 ± 0.05^a	1.58 ± 0.05^b	1.37 ± 0.05^ab	0.95 ± 0.05^c	53.534	< 0.001^***
	声音均匀度指数 AEI	0.84 ± 0.01^a	0.79 ± 0.01^b	0.82 ± 0.01^ab	0.87 ± 0.01^c	50.750	< 0.001^***
	生物声学指数 BIO	10.65 ± 0.38^a	9.45 ± 0.24^ab	8.81 ± 0.24^b	7.43 ± 0.40^c	44.403	< 0.001^***
	标准化声景差异指数 NDSI	0.40 ± 0.04^ab	0.52 ± 0.03^a	0.40 ± 0.04^ab	0.25 ± 0.05^b	14.445	0.002^**
	声音熵指数 H	0.40 ± 0.01^a	0.46 ± 0.01^b	0.42 ± 0.01^ab	0.38 ± 0.01^a	21.746	< 0.001^***
冬季 Winter	声音复杂度指数 ACI	900.38 ± 0.78^a	909.17 ± 1.72^b	901.30 ± 1.12^a	894.93 ± 0.81^c	67.327	< 0.001^***
	声音多样性指数 ADI	0.87 ± 0.04^ab	0.98 ± 0.05^a	0.74 ± 0.04^b	0.47 ± 0.04^c	57.509	< 0.001^***
	声音均匀度指数 AEI	0.88 ± 0.01^a	0.86 ± 0.01^a	0.89 ± 0.01^a	0.91 ± 0.01^b	38.324	< 0.001^***
	生物声学指数 BIO	6.05 ± 0.16^ab	6.54 ± 0.19^a	5.49 ± 0.16^b	4.61 ± 0.11^c	64.825	< 0.001^***
	标准化声景差异指数 NDSI	0.60 ± 0.02^a	0.63 ± 0.02^a	0.60 ± 0.02^a	0.63 ± 0.02^a	3.510	0.320
	声音熵指数 H	0.31 ± 0.01^ab	0.34 ± 0.01^a	0.32 ± 0.01^ab	0.30 ± 0.01^b	8.840	0.031^*

季节 Season	声学指数 Acoustic index	黎明 Dawn	白天 Day	黄昏 Dusk	夜晚 Night	χ2	P
春季 Spring	声音复杂度指数 ACI	908.99 ± 1.36^ab	912.70 ± 1.02^a	903.49 ± 0.89^b	895.68 ± 1.02^c	97.453	< 0.001^***
	声音多样性指数 ADI	1.38 ± 0.05^a	1.09 ± 0.04^b	0.93 ± 0.05^b	0.58 ± 0.05^c	80.140	< 0.001^***
	声音均匀度指数 AEI	0.84 ± 0.01^a	0.87 ± 0.01^b	0.88 ± 0.01^b	0.91 ± 0.01^c	78.321	< 0.001^***
	生物声学指数 BIO	12.79 ± 0.63^a	9.79 ± 0.45^ab	8.38 ± 0.40^b	5.89 ± 0.31^c	78.187	< 0.001^***
	标准化声景差异指数 NDSI	0.57 ± 0.03^a	0.39 ± 0.04^b	0.30 ± 0.04^b	0.22 ± 0.05^b	35.158	< 0.001^***
	声音熵指数 H	0.37 ± 0.01^a	0.38 ± 0.01^a	0.36 ± 0.01^ab	0.34 ± 0.01^b	15.694	< 0.001^***
夏季 Summer	声音复杂度指数 ACI	905.12 ± 1.25^a	898.86 ± 0.85^b	897.38 ± 0.61^b	908.09 ± 2.04^a	43.277	< 0.001^***
	声音多样性指数 ADI	1.61 ± 0.04^ab	1.78 ± 0.05^a	1.64 ± 0.05^a	1.40 ± 0.06^b	27.909	< 0.001^***
	声音均匀度指数 AEI	0.80 ± 0.01^a	0.75 ± 0.01^b	0.78 ± 0.01^ab	0.81 ± 0.01^a	25.499	< 0.001^***
	生物声学指数 BIO	13.27 ± 0.46^a	12.03 ± 0.36^a	11.64 ± 0.34^a	8.81 ± 0.28^b	79.432	< 0.001^***
	标准化声景差异指数 NDSI	0.58 ± 0.04^a	0.67 ± 0.03^a	0.63 ± 0.03^a	0.42 ± 0.05^b	20.688	< 0.001^***
	声音熵指数 H	0.42 ± 0.01^ab	0.51 ± 0.01^c	0.47 ± 0.01^ac	0.41 ± 0.01^b	32.107	< 0.001^***
秋季 Autumn	声音复杂度指数 ACI	902.78 ± 1.06^a	906.87 ± 1.02^b	901.52 ± 0.94^a	897.82 ± 0.86^c	47.306	< 0.001^***
	声音多样性指数 ADI	1.32 ± 0.05^a	1.58 ± 0.05^b	1.37 ± 0.05^ab	0.95 ± 0.05^c	53.534	< 0.001^***
	声音均匀度指数 AEI	0.84 ± 0.01^a	0.79 ± 0.01^b	0.82 ± 0.01^ab	0.87 ± 0.01^c	50.750	< 0.001^***
	生物声学指数 BIO	10.65 ± 0.38^a	9.45 ± 0.24^ab	8.81 ± 0.24^b	7.43 ± 0.40^c	44.403	< 0.001^***
	标准化声景差异指数 NDSI	0.40 ± 0.04^ab	0.52 ± 0.03^a	0.40 ± 0.04^ab	0.25 ± 0.05^b	14.445	0.002^**
	声音熵指数 H	0.40 ± 0.01^a	0.46 ± 0.01^b	0.42 ± 0.01^ab	0.38 ± 0.01^a	21.746	< 0.001^***
冬季 Winter	声音复杂度指数 ACI	900.38 ± 0.78^a	909.17 ± 1.72^b	901.30 ± 1.12^a	894.93 ± 0.81^c	67.327	< 0.001^***
	声音多样性指数 ADI	0.87 ± 0.04^ab	0.98 ± 0.05^a	0.74 ± 0.04^b	0.47 ± 0.04^c	57.509	< 0.001^***
	声音均匀度指数 AEI	0.88 ± 0.01^a	0.86 ± 0.01^a	0.89 ± 0.01^a	0.91 ± 0.01^b	38.324	< 0.001^***
	生物声学指数 BIO	6.05 ± 0.16^ab	6.54 ± 0.19^a	5.49 ± 0.16^b	4.61 ± 0.11^c	64.825	< 0.001^***
	标准化声景差异指数 NDSI	0.60 ± 0.02^a	0.63 ± 0.02^a	0.60 ± 0.02^a	0.63 ± 0.02^a	3.510	0.320
	声音熵指数 H	0.31 ± 0.01^ab	0.34 ± 0.01^a	0.32 ± 0.01^ab	0.30 ± 0.01^b	8.840	0.031^*

声学指数 Acoustic index	春季 Spring	夏季 Summer	秋季 Autumn	冬季 Winter	χ2	P
声音复杂度指数 ACI	903.41 ± 0.82^a	902.39 ± 0.85^a	900.74 ± 0.77^ab	898.72 ± 0.94^b	27.325	< 0.001^***
声音多样性指数 ADI	0.88 ± 0.04^a	1.61 ± 0.04^b	1.18 ± 0.05^c	0.63 ± 0.04^d	115.990	< 0.001^***
声音均匀度指数 AEI	0.89 ± 0.01^a	0.78 ± 0.01^b	0.84 ± 0.01^c	0.90 ± 0.01^a	109.720	< 0.001^***
生物声学指数 BIO	8.32 ± 0.40^a	10.77 ± 0.29^b	8.40 ± 0.31^a	5.19 ± 0.11^c	113.100	< 0.001^***
标准化声景差异指数 NDSI	0.33 ± 0.04^a	0.57 ± 0.03^b	0.36 ± 0.04^a	0.62 ± 0.01^b	56.311	< 0.001^***
声音熵指数 H	0.36 ± 0.01^a	0.46 ± 0.01^b	0.41 ± 0.01^b	0.31 ± 0.01^c	80.463	< 0.001^***

声学指数 Acoustic index	春季 Spring	夏季 Summer	秋季 Autumn	冬季 Winter	χ2	P
声音复杂度指数 ACI	903.41 ± 0.82^a	902.39 ± 0.85^a	900.74 ± 0.77^ab	898.72 ± 0.94^b	27.325	< 0.001^***
声音多样性指数 ADI	0.88 ± 0.04^a	1.61 ± 0.04^b	1.18 ± 0.05^c	0.63 ± 0.04^d	115.990	< 0.001^***
声音均匀度指数 AEI	0.89 ± 0.01^a	0.78 ± 0.01^b	0.84 ± 0.01^c	0.90 ± 0.01^a	109.720	< 0.001^***
生物声学指数 BIO	8.32 ± 0.40^a	10.77 ± 0.29^b	8.40 ± 0.31^a	5.19 ± 0.11^c	113.100	< 0.001^***
标准化声景差异指数 NDSI	0.33 ± 0.04^a	0.57 ± 0.03^b	0.36 ± 0.04^a	0.62 ± 0.01^b	56.311	< 0.001^***
声音熵指数 H	0.36 ± 0.01^a	0.46 ± 0.01^b	0.41 ± 0.01^b	0.31 ± 0.01^c	80.463	< 0.001^***