Medieval Warming, Little Ice Age, and European impact on the environment during the last millennium in the lower Hudson Valley, New York, USA

Abstract

Establishing natural climate variability becomes particularly important in large urban areas in anticipation of droughts. We present a welldated bi-decadal record of vegetation, climate, land use, and fire frequency from a tidal marsh in the Hudson River Estuary. The classic Medieval Warm Period is evident through striking increases in charcoal and Pinus dominance from~800-1300 A.D., paralleling paleorecords southward along the Atlantic seaboard. Higher inputs of inorganic sediment during this interval suggest increased watershed erosion during drought conditions. The presence of the Little Ice Age ensues with increases in Picea and Tsuga, coupled with increasing organic percentages due to cooler, moister conditions. European impact is manifested by a decline in arboreal pollen due to land clearance, increased weedy plant cover (i.e., Ambrosia, Plantago, and Rumex), and an increase in inorganic particles to the watershed.

A Paleoecological Perspective on Wetland Restoration

“…Channel fill deposits that form on a floodplain may time-average fossil assemblages at 100-10,000 years, whereas channel lag and bar deposits may time-average fossil material at even longer intervals (Behrensmeyer and Hook 1992). However, sedimentary deposits where accumulation rates are relatively high will offer the best resolving power (Pederson et al 2005) with some wetlands providing a high temporal sampling resolution, such as less than 10 years per 1 cm of thickness (Yu 2006). Thus, the potential for very high-resolution reconstruction of vegetation composition may exist, although cases of such exceptional temporal resolution are probably the exception rather than the rule.…”

Last millennium environmental changes and climate inferences in the Southeastern Atlantic forest, Brazil

“…A pollen record in Cambará do Sul (29 • 03 09 , 50 • 06 04 Southern Brazil) shows that Weinmannia became a common taxa in the Araucaria forest between 1520 and 1770 AD (∼430 BP and 180 BP) (Behling et al 2004), suggesting a shift to warmer climatic conditions. These authors associated this interval with a cooler phase (∼550 BP to 200 BP) called Little Ice Age (LIA), one of the most important variations of the last millennium (from the 14 th to the 19 th centuries), which is known from North Hemisphere records in the USA, described by Pederson et al 2005, and in the Europe by Fontana, 1976, Font 1988, Ramil-Rego et al 1994 (Clapperton 1983, Rodbell 1992, Solomina et al 2007, 2008, Argentina (Iriondo andGarcía 1993, Piovano et al 2002), Uruguai (Del Puerto et al 2006), Equator (Hastenrath 1981) and Bolivia (Thompson et al 1986, Rabatel et al 2005. The archives for Brazil record the LIA period associated to warm climatic inferences in South region (Behling et al 2004).…”

Basin elevation and salinity changes: late Holocene development of two freshwater lakes at the Karelian White Sea coast, northwest Russia as reflected in their sediments

“…Furthermore, forest clearance (decreasing arboreal pollen) and associated erosion processes in the vicinity of lakes normally cause increased input of mineral matter into the lakes (Pederson et al, 2005). However, the loss on ignition (LOI), an indicator of high mineral inputs and erosion processes (Dean, 1974;Heiri et al, 2001), does not correlate to the (anyway little) changes in AP abundances in the sediment of the study lakes.…”