Gage, S.H. and W. Joo
Presented at the All Scientist Poster Reception (2006-05-09 )
Thirteen locations among the LTER sites were classified into categories: agricultural (4 sites) and forested (9 sites). Agricultural sites consist of two alfalfa plots, and two poplar plots. Forested sites are composed of three coniferous (CF-1, 2, 3), three deciduous (DF-1, 2, 3), and three succession forest plots (SF-1, 2, 3). Recording: Two programmable tape recorders were set in each location and were timed to record in the morning at: 0000, 0530, 0630, 0730, 0830, and 1100 hrs. and during the afternoon at 1430 1600 1830 1930 2030, and 2130 hrs. Recording duration was 3 minutes at each recording time resulting in 12 recordings each day. Environmental acoustic signals were recorded for three days every two weeks from May 18 to July 15, 2005. The recordings were digitized and transferred to a wav file containing a 22 kHz frequency sampling rate and a monaural channel for quantification and analysis of the acoustic signals. Each 3 minute recording was subsequently divided into 30 second acoustic samples for analysis. Three methods were used to analyze the acoustic samples. First the power of the acoustic signal was determined for each of eleven 1 kHz frequency levels. These were partitioned into two main categories based on frequency position. Technophony = 0-2 kHz and Biophony = 3-8 kHz. This analysis was run for each of approximately 1500 30-second samples. These values were summarized for each of the sites samples. Second, Principle Component Analysis was used 1) to partition the sites, 2) the strength of the biophony in each site, and 3) to assess the temporal dynamics of biophony across all sites. Third, each recording made at each site was reviewed and avian signals were identified to species. Species occurrence and number of calls made by each species in each site were compiled. Species diversity was determined using the Shannon-Wiener method.Back to Poster Titles
Back to meeting | Show |