Stable Isotopes Clearly Track Mangrove Inputs and Food Web Changes Along a Reforestation Gradient
- PDF / 1,619,871 Bytes
- 16 Pages / 593.972 x 792 pts Page_size
- 71 Downloads / 185 Views
Stable Isotopes Clearly Track Mangrove Inputs and Food Web Changes Along a Reforestation Gradient Amy Yee-Hui Then,1,2* Maria Fernanda Adame,3 Brian Fry,3 Ving Ching Chong,1 Philip M. Riekenberg,4 Rozainah Mohammad Zakaria,1,2 and Shing Yip Lee3,5 1
Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia; 2Institute of Ocean and Earth Sciences, Universiti Malaya, 50603 Kuala Lumpur, Malaysia; 3Australian Rivers Institute, Griffith University, Nathan, QLD 4111, Australia; 4NIOZ Royal Netherlands Institute for Sea Research, Marine Microbiology and Biogeochemistry Department, Utrecht University, PO Box 59, 1790AB Den Burg, The Netherlands; 5Simon F S Li Marine Science Laboratory, School of Life Sciences, and Earth System Science Programme, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
ABSTRACT Despite worldwide efforts to restore degraded mangrove forests in the past decades, defining and tracking restoration success remains a major challenge. In this study, we used a multi-isotope approach to trace ecosystem responses to forest clearing and replanting in a tropical mangrove forest reserve at Matang, Malaysia. We measured d2H or dD deuterium, d13C and d15N (HCN isotopes) in common macroinvertebrate consumers (barnacles, prawns, gastropods, and crabs) across a 70year chronosequence of mangroves. Functional food web recovery was indicated by a decrease in d13C and d15N and increase in dD for gastropod and crab consumers in older forests. Timing of this shift in food web isotopic signals took place between 5 and 15 years post-clearing of mangroves. These
changes in food web function paralleled changes in crab community composition, but also reflected changes in physicochemical conditions within the forest, such as increased tree cover and shading, which resulted in a shift of the food web base from microalgal-derived to mangrove-derived organic matter. Prawns and barnacles from tidal waters adjacent to the mangrove forests were estimated to derive 17 to 25% of their nutrition from mangroves, primarily from a microbial loop that was processing localised dissolved and particulate organic matter exported from mangrove marshes. The top-down mixing model approach using combined HCN isotope measurements clearly separated inputs from mangroves versus microalgae for the first time in estuarine food web studies, and tracked ecological mangrove ecosystem recovery. This combination of tracers is recommended for future studies of mangrove conservation and restoration.
Received 27 February 2020; accepted 30 August 2020 Electronic supplementary material: The online version of this article (https://doi.org/10.1007/s10021-020-00561-0) contains supplementary material, which is available to authorized users. Authors Contributions SYL, VCC, BF, MFA, RMZ designed the study. SYL, VCC, BF, AT, MFA and RMZ performed the research; BF, PR, AT analysed the data. AT, BF, MFA, PR wrote the paper. *Corresponding author; e-mail: [email protected]
Key words: Carbon; nitrogen; hydr
Data Loading...
