Tom Moir , Megan J. Huggett , Timothy Kirkman , Timothy M. Smith , Troy F. Gaston
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引用次数: 0
Abstract
Globally, seagrass ecosystems are affected by a variety of natural and anthropogenic stressors under a warming climate. Understanding how organisms cope with current stressors, when presented with future warming scenarios, is crucial for predicting ecosystem responses. Here, we use thermal plumes in an east Australian estuary as a proxy for future climate change scenarios to investigate the effects of in situ warming on Zostera muelleri resilience, measured through non-structural carbohydrate (NSC) concentration in the rhizome. NSC's are stored in the rhizome during periods of high photosynthetic efficiency, and are metabolised when photosynthesis is not possible, such as during a storm surge or other stress event. Thermally affected sites in this system experience temperatures 1–6 °C above ambient conditions, with greatest differences in winter months. Despite temperatures frequently exceeding the upper thermal limit (32 °C) for Z. muelleri, we found no significant differences in total NSC concentrations between ambient (80–210 mg g−1) and thermally affected populations (80–170 mg g−1), with only a difference in starch concentration being higher at ambient sites than thermally affected sites during October. A notable shift in NSC composition occurred in July–August 2022 after heavy rainfall in the area, with starch decreasing from 120 to 160 mg g−1 to 20–30 mg g−1, coinciding with increases in fructose and glucose. Thermally affected sites exhibited dampened seasonality in energy reserves suggesting that these populations have adjusted their energy management strategy in response to extended favorable conditions, effectively reducing the amplitude of seasonal NSC fluctuations. These findings support previous findings that larger changes in carbohydrates are driven by temporal patterns and local weather events. They also suggest that Z. muelleri exhibits resilience to elevated temperatures through maintaining comparable total NSC reserves, but with altered temporal patterns of accumulation that likely reflect adaptation to an effectively extended growing season under warming conditions.
期刊介绍:
Marine Environmental Research publishes original research papers on chemical, physical, and biological interactions in the oceans and coastal waters. The journal serves as a forum for new information on biology, chemistry, and toxicology and syntheses that advance understanding of marine environmental processes.
Submission of multidisciplinary studies is encouraged. Studies that utilize experimental approaches to clarify the roles of anthropogenic and natural causes of changes in marine ecosystems are especially welcome, as are those studies that represent new developments of a theoretical or conceptual aspect of marine science. All papers published in this journal are reviewed by qualified peers prior to acceptance and publication. Examples of topics considered to be appropriate for the journal include, but are not limited to, the following:
– The extent, persistence, and consequences of change and the recovery from such change in natural marine systems
– The biochemical, physiological, and ecological consequences of contaminants to marine organisms and ecosystems
– The biogeochemistry of naturally occurring and anthropogenic substances
– Models that describe and predict the above processes
– Monitoring studies, to the extent that their results provide new information on functional processes
– Methodological papers describing improved quantitative techniques for the marine sciences.