TY - JOUR T1 - Paleoecology of mangroves along the Sibun River, Belize JF - Quaternary Research Y1 - 2011 A1 - Monacci, Natalie M. A1 - Meier-Grünhagen, Ursula A1 - Finney, Bruce P. A1 - Behling, Hermann A1 - Wooller, Matthew J. AB - This study examines a sediment core (SR-63) from a mangrove ecosystem along the Sibun River in Belize, which is subject to both changes in sea-level and in the characteristics of the river's drainage basin. Radiocarbon dates from the core show a decreased sedimentation rate from ~ 6 ka to 1 cal ka BP and a marked change in lithology from primarily mangrove peat to fluvial-derived material at ~ 2.5 cal ka BP. Changes in the sedimentation rates observed in mangrove ecosystems offshore have previously been attributed to changes in relative sea-level and the rate of sea-level rise. Pollen analyses show a decreased abundance of Rhizophora (red mangrove) pollen and an increased abundance of Avicennia (black mangrove) pollen and non-mangrove pollen coeval with the decreased sedimentation rates. Elemental ratios ([N:C]a) and stable isotope analyses (δ15N and δ13C) show that changes in the composition of the organic material are also coeval with the change in lithology. The decrease in sedimentation rate at the site of core SR-63 and at offshore sites supports the idea that regional changes in hydrology occurred during the Holocene in Belize, influencing both mainland and offshore mangrove ecosystems. VL - 76 UR - http://www.sciencedirect.com/science/article/pii/S003358941100069X IS - 2 N1 - id: 2099 JO - Paleoecology of mangroves along the Sibun River, Belize ER - TY - JOUR T1 - A multiproxy peat record of Holocene mangrove palaeoecology from Twin Cays, Belize JF - The HoloceneThe Holocene Y1 - 2007 A1 - Wooller, Matthew J. A1 - Morgan, Rebecca A1 - Fowell, Sarah A1 - Behling, Hermann A1 - Fogel, Marilyn AB - The extent and function of coastal mangrove ecosystems are likely to be influenced by future changes in sea level. Multiple proxies of past mangrove ecosystems preserved in a 780 cm long peat core (TCC2) taken from Twin Cays, Belize, record palaeoecological changes since ~8000 cal. yr BP. The proxies included pollen and the stable-isotope (C, N and O) compositions of mangrove leaf fragments. Rhizophora mangle (red mangrove) has been dominant at this site on Twin Cays for over ~8000 years. Variations in δ13 C and δ15N suggest past changes in stand structure between dwarf, transition and tall R. mangle through the Holocene. Marked changes in the δ18O (up to ~4?) of mangrove leaf fragments throughout TCC2 most likely record variations in the proportion of seawater versus precipitation taken up by past mangroves, reflecting the degree of inundation of the site with seawater resulting from changes in the rate of Holocene sea-level rise. Notably, a decline in peat accumulation rate at ~7200 cal. yr BP correlates with a decrease in the rate of rise in sea level. This was not accompanied by a marked change in the pollen assemblages. However, changes in assemblage composition began to occur ~6300 cal. yr BP, with an increase in Myrsine-type and Avicennia germinans (black mangrove) pollen. An increase in the δ18O between 6100 and 5300 cal. yr BP, which correlates with other records from Central America, indicates a significant increase in the rate of rise in sea level.The extent and function of coastal mangrove ecosystems are likely to be influenced by future changes in sea level. Multiple proxies of past mangrove ecosystems preserved in a 780 cm long peat core (TCC2) taken from Twin Cays, Belize, record palaeoecological changes since ~8000 cal. yr BP. The proxies included pollen and the stable-isotope (C, N and O) compositions of mangrove leaf fragments. Rhizophora mangle (red mangrove) has been dominant at this site on Twin Cays for over ~8000 years. Variations in δ13 C and δ15N suggest past changes in stand structure between dwarf, transition and tall R. mangle through the Holocene. Marked changes in the δ18O (up to ~4?) of mangrove leaf fragments throughout TCC2 most likely record variations in the proportion of seawater versus precipitation taken up by past mangroves, reflecting the degree of inundation of the site with seawater resulting from changes in the rate of Holocene sea-level rise. Notably, a decline in peat accumulation rate at ~7200 cal. yr BP correlates with a decrease in the rate of rise in sea level. This was not accompanied by a marked change in the pollen assemblages. However, changes in assemblage composition began to occur ~6300 cal. yr BP, with an increase in Myrsine-type and Avicennia germinans (black mangrove) pollen. An increase in the δ18O between 6100 and 5300 cal. yr BP, which correlates with other records from Central America, indicates a significant increase in the rate of rise in sea level. VL - 17 SN - 0959-6836 UR - http://journals.sagepub.com/doi/abs/10.1177/0959683607082553 IS - 8 ER -