Effects of Hydroclimatic Change and Rehabilitation Activities on Salinity and Mangroves in the Ci\xe9naga Grande de Santa Marta, Colombia

Fernando Jaramillo,Oscar Martínez,Stefano Manzoni,Alice Guittard,Jenny Alexandra Rodríguez-Rodríguez,Lucía Licero,Jiner Bolaños,Imenne Åhlen,Shimon Wdowinski,James Jawitz,Anna Hylin,Luisa Fernanda Espinosa

doi:10.1007/s13157-018-1024-7

Abstract

The Ciénaga Grande de Santa Marta (CGSM), Colombia is possibly the wetland that has experienced the largest mangrove mortality on record due to modification of hydrologic connectivity and consequent hypersaline conditions. We used hydroclimatic, salinity and mangrove basal area data collected in five stations from 1993 to 2015 to study the relation between ongoing mangrove recovery, changes in salinity in the wetland and hydroclimatic changes in precipitation, potential evapotranspiration and freshwater inputs. We found that until 2015, the mangrove ecosystems in CGSM are in general terms in a path of recovery due to the combined effect of favorable hydroclimatic conditions and management operations to increase freshwater inputs into the wetland. We observed in three stations that the annual growth of mangrove basal area increased as pore water salinity decreased. Regarding surface water salinity, El Niño/Southern Oscillation explained most of the inter-annual variability in the wet season by regulating freshwater and in the dry season by regulating potential evaporation from the wetland. However, persistent channel reopening appeared to be the cause for the largest salinity decreases, whereas lack of persistent dredging slowed recovery in other areas. The monitoring of the mangrove-salinity-hydroclimate system must continue in order to increase its understanding and to avoid more recurring episodes of mangrove mortality.

Highlights

Mangrove forests are coastal ecosystems that provide at least US $1.6 billion/yr. in ecosystem services and support global coastal livelihoods (Polidoro et al 2010; Thorslund et al 2017)
We first studied the effect of salinity on mangrove growth and recovery by analyzing the annual growth rate in mangrove basal, BA occurring during that specific year interval (BAint) along with pore water salinity (Fig. 2a)
Until 2015, the mangrove ecosystems in Ciénaga Grande de Santa Marta (CGSM) are in general terms in a path of recovery after the massive mortality episodes occurring between 1960 and 1994

Summary

Introduction

Mangrove forests are coastal ecosystems that provide at least US $1.6 billion/yr. in ecosystem services and support global coastal livelihoods (Polidoro et al 2010; Thorslund et al 2017). Natural or anthropogenic changes to these configurations may become drivers of stress (Foti et al 2013), affecting mangrove development, increasing. Natural drivers of stress in coastal wetlands include lightning, herbivory, frost, tropical storms, changes in sea level, and long-term climate variability (Osland et al 2013). Of these drivers, changes in sea level have generated recently great concern due to unprecedented climate change. Modifications of hydrological regimes are a main reason for mangrove mortality worldwide (e.g. Cintron et al 1978; Cardona and Botero 1998; Barreto 2008; Sakho et al 2011)

Methods

Results

Discussion

Conclusion