Environmental Drivers in Mangrove Establishment and Early Development: A review

background

This study reviews literature on the environmental conditions that influence the establishment and early growth of mangroves.

Research Goals & Methods

Different species grow in areas with different flooding regimes. The authors used the classification of "inundation by all high tides, inundation by medium high tides, inundation by normal high tides, inundation by spring tides, and occasional inundation by exceptional or equinoctial tides."

Conclusions & Takeaways

Mangrove species are generally able to tolerate a variety of salinity and fertility conditions. Mangrove species grow relatively slowly, but can see significant growth improvements from fertilization with a combination of nitrogen, potassium, and phosporous or potassium alone. Nitrogen fertilization along did not improve growth. However, fertilization with phosphorous increased herbivory by leaf-boring insects and caused trees to grow more tender leaves. Temperature is generally considered the limiting factor for mangrove distribution latitudinally, but some species are more tolerant of freezing than others. The impact of high temperatures have not been as well studied, but there is evidence that there are important changes in roots around 30°C and that plants may be able to tolerate short temperature shocks, but longer exposure to higher temperatures can be fatal. Salinity has important impacts on mangrove growth. Propagules are likely the most sensitive life stage to high salt concentrations. High salinities are more energetically demanding than lower salinities, but variations in salinity are even more demanding. Flooding reduces oxygen availability in the soils, and young trees appear to be the most sensitive to flooding. Experimental simulations of sea level rise show increased stress and decreased growth rates.