Past and potential future distribution of white mangroves in an arid estuarine environment: Integration of Maxent and CA-Markov models

Abstract

This study performed a coupled modeling approach to assess the past-to-future distribution of white mangrove trees (Avicennia marina) along an intertidal zone in the Strait of Hormuz. Historical mangrove distributions were extracted from 3 temporally-median-filtered Landsat images in 2002 (ETM+), 2011 (TM), and 2020 (OLI). The mangrove habitat suitability was investigated using the Maxent model, employing distance from shoreline, creeks, and mangroves, elevation and sediment physio-chemical characteristics. The sediment attributes including EC, pH, sediment texture, total organic carbon, bulk density, and total nitrogen and phosphorous were measured at 25 sampling points and interpolated using the IDW technique. The resulting habitat layer was used as the transition layer in the CA-Markov to predict the future distribution of mangroves by 2030 and 2040. From 2002–2020, the mangrove cover increased by 165 ha (annual rate of 8.19 ha) through both edge- and out-growth patterns. The habitat suitability modeling was performed successfully with an AUC of 0.962 with distance from mangrove patches, distance from water creeks, sediment texture, and phosphorous as the most important predictors. According to the CA-Markov prediction (AUC of 0.690), the area of mangroves is projected to increase to 497 and 543 ha in a compact edge-growth pattern by 2030 and 2040, respectively.