ZS Issue

Effects of Tropical Cyclone Passage on Plankton Community Respiration in a Phosphate-Limited Freshwater Ecosystem

Erica Silk P. dela Paz, Chao-Chen Lai, Fuh-Kwo Shiah, Chih-hao Hsieh, Chia-Ying Ko^*

Erica Silk P. dela Paz

Institute of Fisheries Science, National Taiwan University, Taipei, 106 Taiwan.

d07b45003@ntu.edu.tw

Chao-Chen Lai

Department of Science Education, National Taipei University of Education, Taipei 106, Taiwan.

ccjosephlai@mail.ntue.edu.tw

Fuh-Kwo Shiah

Research Center for Environmental Changes, Academia Sinica, Taipei 115, Taiwan.

fkshiah@gate.sinica.edu.tw

Chih-hao Hsieh

Research Center for Environmental Changes, Academia Sinica, Taipei 115, Taiwan

Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan

Master’s Program in Biodiversity, Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei, 106 Taiwan

chsieh@ntu.edu.tw

Chia-Ying Ko

Institute of Fisheries Science, National Taiwan University, Taipei, 106 Taiwan

Master’s Program in Biodiversity, Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei, 106 Taiwan

cyko235@ntu.edu.tw

Communicated by Benny Kwok Kan Chan

Plankton community respiration (CR) in aquatic ecosystems varies with environmental factors, which could be altered during tropical cyclones (TCs). A potential increase in CR resulting from the effects of TCs is generally understudied. Here, we examined the relationship between plankton CR and environmental factors, including during TC-affected periods, in a phosphate-limited freshwater ecosystem. We conducted an intensive in situ sampling in Fei-Tsui Reservoir (FTR) from January 2010 to December 2015 during TC periods and non-TC periods. Our results showed a consistent temporal pattern that plankton CR increased between March to October and declined between November to February. These changes in plankton CR, primarily supported by bacterial biomass, were positively influenced by euphotic depth-averaged temperature. The CR also significantly increased with euphotic depth-averaged NO₂^- concentrations and decreased with euphotic depth-averaged NO₃^- concentrations. These results indicated that these factors typically influenced CR dynamics in the FTR. During TC periods, plankton CR was increased further due to a higher and ideal euphotic depth-averaged temperature (23–27°C) and increased supply of limiting nutrient resources via stream runoff. Overall, this study showed that a TC positively influences plankton CR by creating favorable water conditions. Notably, with a higher frequency of intense TCs projected for the Western North Pacific in most climate change scenarios, the impact of TCs on CR may increase in the near future.

Keywords

Bacterial biomass, Total community respiration, Oligotrophic lake, Plankton, Typhoon

Supplementary materials

Boxplots comparing euphotic depth-averaged plankton community respiration between tropical cyclone (TC) and non-TC periods using data from May to November of each year’s study period. The euphotic depth spans from 0–20 m on average. The p-value estimated by the Mann-Whitney U test is shown. (download)

Time series pattern of (a) precipitation, (b) euphotic depth-averaged temperature, (c) dissolved oxygen (DO), (d) dissolved organic carbon (DOC), (e) NO₂ ^-, (f) NO₃ ^-, (g) PO₄ ³- concentrations. The euphotic depth spans from 0-20 m on average. (download)

Results of Levene’s test for equal variances and Shapiro-Wilk normality test. (download)

Autocorrelation tests of factors during tropical cyclone (TC) periods and Non-TC periods. (download)