Mangrove dynamics in the southwestern Caribbean since the ‘Little Ice Age’: A history of human and natural disturbances

Abstract

Relatively little is known about the long-term response of Caribbean mangroves to human and natural disturbances during the ‘Little Ice Age’ (LIA). We present new palynological information on the dynamics of the Bahia Honda mangrove from the eastern coast of San Andres Island in the southwestern Caribbean for the late Holocene. Major changes in the Bahia Honda pollen record show the combined effects of natural events (strong storms and sea-level rise), and human disturbances. These changes are supported by 14C dates, sedimentological and palynological information. A storm (most probably a hurricane) was recorded around AD 1600, caused sediment reworking and the subsequent loss of about 2000 years of the vegetation record. The devastation of tree vegetation by this event allowed the expansion of heliophytic vegetation (e.g. grasses and vines). Mangroves and coastal vegetation started to recover at AD 1700, reaching their maximum extent within a few decades, when microforaminifera shells became abundant at the coring site, thus suggesting a relative sea-level rise because of the geomorphic reconfiguration of the coastal plain after the storm. Furthermore, the pollen evidence indicates more humid regional climates during the late LIA (AD 1700—1850). Mangrove and coastal vegetation declined sharply as a consequence of the establishment of coconut plantations around AD 1850. The recovery of the mangroves after AD 1960 is a result of the combined effect of relative sea-level rise and drastic changes in the local economy from coconut plantations to commerce.

Middle to late Holocene relative sea level rise, climate variability and environmental change along the Colombian Caribbean coast

“…Most of what we know about late Holocene sea level changes in the Colombian Caribbean is based on pollen (Gonzalez et al, 2010;Palacios et al, 2012;Urrego et al, 2013;Van der Hammen and Noldus, 1984), petrographic analysis of organic matter (Cohen and Wiedemann, 1973), and sedimentological analyses (Jaramillo et al, 2012;Martínez et al, 2010). This study presents a record of sea level rise and environmental change for the Colombian Caribbean, inferred from analyses of diatoms, stable isotopes, lithology, and C/N ratios of organic matter, in a sediment core from the CGSM.…”

A 1900‐year paleohurricane record from Wassaw Island, Georgia, USA

“…Paleohurricanes have been identified as removing >1500 years of sedimentation in both Belize (McCloskey and Keller, 2009) and San Andreas Island off the coast of Nicaragua (González et al . 2010). Such erosion could also account for the missing quiet period in core W‐3, if the erosion associated with the recent active period removed sufficient amounts of the surface material.…”

Dinámica del manglar en el complejo lagunar de Cispatá(Caribe colombiano) en los últimos 900 años

“…Esta tendencia de incremento en las poblaciones de manglar a partir de 1850, se ha registrado en otros ecosistemas tropicales (Cohen et al 2005, Carvalho et al 2006) y se ha asociado con el incremento en el nivel del mar y las precipitaciones (Rull 1999, Polissar et al 2006, González et al 2010) hacia el final de la PEH, durante la cual estos fueron menores. Esta expansión de los manglares en Cispatá desde 1850 es el resultado del efecto combinado de los cambios geomorfológicos, que involucran altas tasas de acreción gobernadas por las descargas de sedimentos aluviales y el incremento en el nivel del mar, tal como se ha registrado en otros sitios (Woodroffe 1990, Parkinson et al 1994, Snedaker 1995, Alongi 2008.…”

“…investigaciones paleoecológicas realizadas en el Caribe colombiano, han mostrado la respuesta de los manglares a fenómenos locales de subsidencia, variaciones en la dinámica fluvial, así como a cambios en el nivel del mar y la actividad antrópica durante el Holoceno tardío (Castaño 2004, González et al 2010. Sin embargo, aún no se conoce la significancia regional de estos fenómenos y quedan muchas preguntas acerca de la respuesta de los manglares a los cambios ambientales recientes; en especial, no se sabe en qué proporción la evolución de los manglares responde a los cambios climáticos, los geomorfológicos o al efecto combinado de ambos.…”