Florida mangrove dieback on a decadal and centennial timescales.

Hurricanes are considered some of the most devastating weather phenomena, causing deaths and destruction along the coast. Mangroves are perceived as natural defenses against coastal hazards. However, mangrove gaps, known as mangrove dieback, have occurred in southwestern Florida.

Hurricanes are limiting the mangrove canopy heights in the Gulf of Mexico.

Mangrove canopy height (MCH) has been described as a leading characteristic of mangrove forests, protecting coastal economic interests from hurricanes. Meanwhile, winter temperature has been considered the main factor controlling the MCH along subtropical coastlines. However, the MCH in Cedar Key, Florida (∼12 m), is significantly higher than in Port Fourchon, Louisiana (∼2.

Assessment the Impacts of Sea-Level Changes on Mangroves of Ceará-Mirim Estuary, Northeastern Brazil, during the Holocene and Anthropocene.

Predictions of the effects of modern Relative Sea-Level (RSL) rise on mangroves should be based on decadal-millennial mangrove dynamics and the particularities of each depositional environment under past RSL changes. This work identified inland and seaward mangrove migrations along the Ceará-Mirim estuary (Rio Grande do Norte, northeastern Brazil) during the mid-late Holocene and Anthropocene based on sedimentary features, palynological, and geochemical (δC, δN, C/N) data integrated with spatial-temporal analysis based on satellite images. The data indicated three phases for the mangrove development: (1°) mangrove expansion on tidal flats with estuarine organic matter between >4420 and ~2870 cal yrs BP, under the influence of the mid-Holocene sea-level highstand; (2°) mangrove contraction with an increased contribution of C terrestrial plants between ~2870 and ~84 cal yrs BP due to an RSL fall, and (3°) mangrove expansion onto the highest tidal flats since ~84 cal yr BP due to a relative sea-level rise.

Uncoupling human and climate drivers of late Holocene vegetation change in southern Brazil.

In the highlands of southern Brazil an anthropogenitcally driven expansion of forest occurred at the expense of grasslands between 1410 and 900 cal BP, coincident with a period of demographic and cultural change in the region. Previous studies have debated the relative contributions of increasing wetter and warmer climate conditions and human landscape modifications to forest expansion, but generally lacked high resoltiuon proxies to measure these effects, or have relied on single proxies to reconstruct both climate and vegetation. Here, we develop and test a model of natural ecosystem distribution against vegetation histories, paleoclimate proxies, and the archaeological record to distinguish human from temperature and precipitation impacts on the distribution and expansion of Araucaria forests during the late Holocene.