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Evaluating the Characters of Songbirds’ Vocalizations during Mobbing Event in Dark Coniferous Forest Using Bio-acoustic Indicators

WANG Jiangyue, TIAN Jia, ZHOU Zhengyang, MA Xiaoyun, LONG Yu, WANG Rongjiang, LI Sheng

Acta Scientiarum Naturalium Universitatis Pekinensis 2024, 60 (1): 118-126. DOI: 10.13209/j.0479-8023.2023.099

Abstract （681）

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This study investigated the acoustic variation of songbirds’ vocalization during mobbing event in the sub-alpine forests using playback experiment and automatic acoustic recording (AAR). We played Glaucidium brodiei vocalization and Phylloscopus trochiloides alarm call to induce songbirds’ mobbing behavior and recorded their response vocalizations using automatic acoustic recorders in the Abies-Picea dark coniferous forest in Wanglang National Nature Reserve, Sichuan Province, during the summer of 2021. Altogether 24 experiments were performed on 12 experiment sites, with a total length of 1057 min acoustic recordings, including 12 G. brodiei vocalization experiments, and 12 P. trochiloides alarm call experiments. A total of 28 species of birds belonging to 17 families and 3 orders were observed to participate in mobbing behavior. By analyzing the acoustic indexes of recordings, it was concluded that 1) both G. brodiei vocalization and P. trochiloides alarm call could trigger mobbing event, during which Phylloscopidae and Paridae species were the majority being involved; 2) during playback period, songbirds’ vocalizations are more intense (G. brodiei experiments: SPL_avg=−31.02±4.87 dB vs −42.74±4.68 dB, p = 0.001; P. trochiloides experiments: SPL_avg = −33.26±4.05 dB vs −46.38±4.54 dB, p = 0.001) and less complicated (G. brodiei experiments: H = 0.76±0.02 vs 0.80±0.03, p = 0.001; P. trochiloides experiments: H = 0.77±0.02 vs 0.82±0.02, p = 0.001) than that of pre-playback period; 3) the variability of acoustic indices from pre-playback to during-playback didn’t change significantly between G. brodiei experiments and P. trochiloides experiments. The results provide a new insight into avian behavior studies in the acoustic aspect, and novel behavioral application scenarios for large-scale soundscape monitoring data.

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Grain for the Green Spatial Pattern Optimization in the Middle Reaches of Heihe River Based on Water Carrying Capacity

MENG Jijun, ZHOU Zhen, KUO Lijen

Acta Scientiarum Naturalium Universitatis Pekinensis 2019, 55 (3): 526-536. DOI: 10.13209/j.0479-8023.2019.030

Abstract （765）

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This paper takes the middle reaches of Heihe River as the study area, where has the most concentrated oasis in Northwest China with fragile ecological environment and huge conflict between water supply and demand. The water carrying capacity was analyzed based on SD model. Then, the land use quantity structure optimization was carried out by grey linear planning model under the constraint of water resource carrying capacity. Next, the probability of cultivated land, forest and grass land was calculated by the space optimization module of Dyna-CLUES model, and the optimized spatial pattern were identified through probability game. The results show that when the balance between the supply and demand of water resources is achieved in 2020, the research area can support 1.44 million people, 7.973 billion industrial added values, separately the forests, grass land and cultivated land that the research area can support is 953.535 km², 3947.115 km² and 3027.88 km². The best landscape quantity structure include 2742.49 km² cultivated land, 846.456 km² forest, 2184.57 km² grass land, 170.671 km² water area, 364.509 km² construction land and 13289.23 km² unutilized land. The implementation of returning cropland to forests can enhance the ability of oasis areas to resist hazards caused by wind and sand, mainly in Gaotai, Linze and Ganzhou. The locations of returning cropland to grassland focus in Shandan and Sunan with high altitude, steep slope and poor water, which have poor soil condition and is inappropriate for forest. Forest plantation locations focus in the periphery of cropland in Minle and Shandan, and those areas mainly are flat unused land with good water resource conditions, which are of great significance for water and soil conservation, wind prevention and sand fixation.

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A Study of Ecological Water Requirement and Efficiency of Water Allocation Based on Oasis Irrigation Area Scale: A Case of Middle Reaches of Heihe River

MENG Jijun, WANG Jiangwei, WANG Ya, ZHOU Zhen, JIANG Song

Acta Scientiarum Naturalium Universitatis Pekinensis 2018, 54 (1): 171-180. DOI: 10.13209/j.0479-8023.2017.142

Abstract （882）

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Based on many data sources, such as basic geographic information, land use and cover information and statistic data of irrigation areas, the authors picked agricultural irrigation areas in the middle reaches of Heihe river as a study area and analyzed the spatial-temporal distributions of ecological water requirement with Penman-Monteith equation and NDVI data. Considering the real water diversion and consumption per unit grain yield, the efficiency of water allocation was also analyzed. The results show that the annual potential evapotranspiration is between 800 and 1200 mm and the peak occurs between June and August. Average annual potential evapotranspiration is between 614 and 999 mm while maximum of demand appears from April to August. Ecological water requirement reduces from southeast to northwest gradually which is relatively larger along the Heihe river. Ground water plays major role in water diversion while underground water is minor. The yield of water diversion is the largest in 2008 and irrigation areas which have more water diversions flock around the Heihe river. Overall, water resource allocation overthere is fair good. Water supply-demand rate around Heihe river is generally greater than 1 while it is opposite in Shandan and Minle. Nearly 80% of the irrigation areas can be considered as efficient or relative efficient regions. There are four irrigation districts are inefficient and only one is short of water diversion. Therefore, adjustment of water diversion in some certain regions with promotion of water saving technology can enhance the efficiency of water allocation roundly. The results provide feasible reference to improve the efficiency of water allocation in arid area.

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A Feasibility Study on the Development of Large-Scale Nuclear Power Plant Clusters in Western Deserts of China

GAO Xiang,LIU Xiaochen,MA Xiao,WANG Gan,LIU Zhe,NIE Xuhui,ZHOU Zhenyu,PAN Ruizhi,LIANG Shiyu,YANG Tianhe,ZHU Jinhua,XU Shengyong

Acta Scientiarum Naturalium Universitatis Pekinensis

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A Note on Computing the Tate Pairing with Efficiently Computable Endomorphisms

HU Zhi,ZHOU Zhenghua,XU Maozhi

Acta Scientiarum Naturalium Universitatis Pekinensis

Abstract （821）

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The authors examine faster computation of Tate pairing on elliptic curves by using some efficiently computable endomorphism. Focused on two typical types of elliptic curves with even embedding degree k, Miller algorithm with some endomorphisms is modified. The authors analyze the efficiency for k = 2, and give the certain conditions and several examples, under which the proposed method is specifically faster than the traditional one.

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Improvement on the Natural Dictionary-ordering Method in Reliability Growth Tests

ZHENG Zhongguo,CAO Dachuang,ZHOU Zhengfa

Acta Scientiarum Naturalium Universitatis Pekinensis

Abstract （629）

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In a m-stage reliability growth test, to estimate the lower confidence limit of the reliability of the system in the final stage, randomization is introduced to improve the exsiting natural chain method. Simulation study shows that when the number of stages is one, the randomization method is ideal.

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