The most vulnerable and dynamic ecosystems in terms of response to climate change and fluctuations
in hydrological conditions are mangroves, particularly those located on the edge of their latitudinal
range limits. The four primary Iranian mangrove forest sites: Nayband, Qeshm, Gabrik, and Govatr,
located in the northern part of the Persian Gulf and the Gulf of Oman already exist near the limit of
their tolerance to extreme temperature, precipitation, and salinity. Due to extreme climate conditions at
these locations, the mangrove trees are usually smaller and less dense as compared with mangroves
closer to the equator complicating their monitoring and mapping efforts. Despite the growing attention
to the ecological benefits of mangrove forests and their importance in climate change mitigation, there
are still a few studies on these marginal mangroves. Therefore, we investigated whether the variation in
mangrove ecosystem health is related to the changes in physical parameters and differs between
estuarine and sea-side locations. We developed a comprehensive database on NDVI values, associated rainfall, temperature, and river flow based on in-situ and remote sensing measurements. By
understanding the normal hydrologic patterns that control the distribution and growth of mangroves in
arid and semi-arid regions, we are questioning the need for environmental flow allocation to restore
mangrove ecosystem health. This brings us to the second gap in the literature and the need for further
studies on Environmental Flow assessment for intermittent and ephemeral rivers. Alike other
mangroves studied, forests showed greenness seasonality, positively correlated with rainfall, and
negatively correlated with temperature. As there was no clear difference between estuarine and marine
sites, freshwater influence in the form of river flow, unlike temperature, cannot be considered a major
limiting factor. Nevertheless, during prolonged droughts mangroves could benefit from the
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