Seagrass Proliferation Precedes Mortality during Hypo-Salinity Events: A Stress-Induced Morphometric Response

摘要: Halophytes, such as seagrasses, predominantly form habitats in coastal and estuarine areas. These can be seasonally exposed to hypo-salinity events during watershed runoff exposing them dramatic salinity shifts osmotic shock. The manifestation of this shock on seagrass morphology phenology was tested three Indo-Pacific species, Halophila ovalis, Halodule uninervis Zostera muelleri, ranging from 3 36 PSU at increments for 10 weeks. All species had broad tolerance but demonstrated a moderate stress response – analogous induced morphometric (SIMR). Shoot proliferation occurred salinities <30 PSU, with the largest increases, up 400% increase shoot density, occurring sub-lethal <15 specific associated peak density being variable among species. Resources were not diverted away leaf growth or development support new production. However, where shoots proliferated, flowering severely reduced H. only flower experiment, demonstrating diversion resources sexual reproduction investment shoots. This SIMR preceded mortality, which ovalis 6 uninervis, while complete mortality reached Z. muelleri. is first study identify detectable due fine resolution treatments tested. detection demonstrates need caution interpreting in-situ changes could interpreted healthy positive plant environmental conditions, when fact it signal pre-mortality stress.