Environmental factors controlling structure, litter productivity, and phenology of mangroves in arid region of the Gulf of California

Mangroves are highly productive ecosystems permanently contributing, through their litter productivity, with organic material into the superior trophic compartments. This research took place in three coastal lagoons on the southeast coast of the Gulf of California. The objective is to describe environmental factors controlling structure, phenological, and litter productivity in arid zone mangruves. The study sites were established along a latitudinal arid climate gradient, were evaporation (∼3000 mm year⁻¹) exceeds precipitation (∼300 mm year⁻¹), and a microtidal regime predominates. The study period was from June 2018 to May 2019. Litter productivity was quantified using litter traps, while piezometer were used to monitor surface, interstitial, and groundwater physicochemical properties and the water level. The different mangrove species present in the study area are influenced by high interstitial salinity, due to scarce freshwater inputs, because precipitation runoff is limited to the monsoon (June–August). The flowering phenophase started before the monsoon and peaked during the monsoon season, propagules production was highest in september and peaked from august to october (highest water level). Air and water temperature in warmer months influenced flower and propagules production. Despite the harsh environmental conditions provide a suboptimal scenario for mangroves to grow, resulting in low structural development and low litter productivity (∼4 Mg ha⁻¹ year⁻¹) influenced by temperature, and water properties (i.e. temperature, salinity and ORP), precipitation and flood pattern. An important highlight of this research is the triggered phenological response to temperature (air and water), therefore the importance of long-term monitoring of such processes and variables.