@article {1954,
	title = {A climatic driver for abrupt mid-Holocene vegetation dynamics and the hemlock decline in New England},
	journal = {Ecology},
	volume = {87},
	year = {2006},
	note = {Foster, David ROswald, W Wyatt
Faison, Edward K
Doughty, Elaine D
Hansen, Barbara C S
eng
Research Support, Non-U.S. Gov{\textquoteright}t
Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S.
2007/01/26 09:00
Ecology. 2006 Dec;87(12):2959-66.
},
	month = {Dec},
	pages = {2959-66},
	abstract = {The mid-Holocene decline of eastern hemlock is widely viewed as the sole prehistorical example of an insect- or pathogen-mediated collapse of a North American tree species and has been extensively studied for insights into pest-host dynamics and the consequences to terrestrial and aquatic ecosystems of dominant-species removal. We report paleoecological evidence implicating climate as a major driver of this episode. Data drawn from sites across a gradient in hemlock abundance from dominant to absent demonstrate: a synchronous, dramatic decline in a contrasting taxon (oak); changes in lake sediments and aquatic taxa indicating low water levels; and one or more intervals of intense drought at regional to continental scales. These results, which accord well with emerging climate reconstructions, challenge the interpretation of a biotically driven hemlock decline and highlight the potential for climate change to generate major, abrupt dynamics in forest ecosystems.},
	keywords = {*Climate, *Ecosystem, Geologic Sediments, new england, Tsuga/*physiology},
	isbn = {0012-9658 (Print)0012-9658 (Linking)},
	doi = {10.1890/0012-9658(2006)87[2959:ACDFAM]2.0.CO;2},
	author = {Foster, D. R. and Oswald, W. W. and Faison, E. K. and Doughty, E. D. and Hansen, B. C.}
}
@article {1955,
	title = {Early holocene openlands in southern New England},
	journal = {Ecology},
	volume = {87},
	year = {2006},
	note = {Faison, E KFoster, D R
Oswald, W W
Hansen, B C S
Doughty, E
eng
Research Support, Non-U.S. Gov{\textquoteright}t
Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S.
2006/11/09 09:00
Ecology. 2006 Oct;87(10):2537-47.
},
	month = {Oct},
	pages = {2537-47},
	abstract = {The pre-historical vegetation structure in temperate forest regions is much debated among European and North American ecologists and conservationists. Frans Vera{\textquoteright}s recent hypothesis that large mammals created mosaics of forest and openland vegetation in both regions throughout the Holocene has been particularly controversial and has provoked new approaches to conservation management. Thirty years earlier, American paleoecologists Herb Wright and Margaret Davis debated whether abundant ragweed pollen at Rogers Lake, Connecticut at 9500 yr BP signified local forest openings or long-distance transport of pollen from Midwestern prairies. Using new pollen records from Harvard Forest and the North American Pollen Database, we address this question and offer insights to the openland discussion. Ragweed and other forbs exceed 3.5\% at five sites in a restricted area of southern New England between 10,100 and 7700 yr BP. Strong evidence suggests this pollen originated from the landscapes surrounding these sites (supporting Davis), as ragweed pollen percentages do not increase with longitude from New England to the Midwest. Ragweed pollen percentages are also unrelated to basin size and therefore unrelated to the proportion of extraregional pollen in New England. High forbs values were associated with increases in oak, decreases in white pine, and relatively high charcoal values. Modern pollen records with similar forb and tree percentages occur along the Prairie Peninsula region of the Upper Midwest. However, the closest analogue to the southern New England early Holocene assemblages comes from Massachusetts{\textquoteright} Walden Pond in the early 18th century. These results and the affiliation of ragweed for open, disturbed habitats suggest that oak-pine forests with large openings persisted for over 2000 years due to dry conditions and perhaps increased fire frequency. This conclusion is corroborated by independent lake level and climate reconstructions. Because these early Holocene openlands have no detectable analogue in New England for the past 7000 years before European settlement, we suggest that all important openlands today are almost exclusively a legacy of Colonial agriculture and should be managed accordingly. Nonetheless, our results may have implications for forest dynamics accompanying projected climate change to more arid conditions in New England over the next century.},
	keywords = {*Ambrosia, *Pollen, Ecosystem, Geography, new england, Paleontology},
	isbn = {0012-9658 (Print)0012-9658 (Linking)},
	doi = {10.1890/0012-9658(2006)87[2537:EHOISN]2.0.CO;2},
	author = {Faison, E. K. and Foster, D. R. and Oswald, W. W. and Hansen, B. C. and Doughty, E.}
}
@article {1828,
	title = {Impact of human activity on regional forest composition and dynamics in central New England},
	journal = {Ecosystems},
	volume = {1},
	year = {1998},
	month = {Jan-Feb},
	pages = {76-95},
	abstract = {Historical and ecological data from north-central Massachusetts suggest that widespread and intensive human disturbance after European settlement led to a shift in forest composition and obscured regional patterns of species abundance. A paleoecological approach was required to place recent forest dynamics in a long-term context. Pollen and charcoal data from 11 small lakes in north-central Massachusetts were used to reconstruct local vegetation dynamics and fire histories across the region over the past 1000 years. The sites are located across an environmental gradient. Paleoecological data indicate that prior to European settlement, there was regional variation in forest composition corresponding to differences in climate, substrate, and fire regime. Oak, chestnut, and hickory were abundant at low elevations, whereas hemlock, beech, sugar maple, and yellow birch were common at high elevations. Fire appears to have been more frequent and/or intense at lower elevations, maintaining high abundances of oak, and archaeological data suggest Native American populations were greater in these areas. A change in forest composition at higher elevations, around 550 years before present, may be related to the Little Ice Age (a period of variable climate), fire, and/or activity by Native Americans, and led to regional convergence in forest composition. After European settlement, forest composition changed markedly in response to human disturbance and there was a sharp increase in rates of vegetation change. Regional patterns were obscured further, leading to homogenization of broad-scale forest composition. There is no indication from the pollen data that forests are returning to pre-European settlement forest composition, and rates of vegetation change remain high, reflecting continuing disturbance on the landscape, despite regional reforestation.},
	keywords = {awenda provincial park, eastern north-america, european settlement, forest dynamics, history, human disturbance, lake sediment, land-use, new england, paleoecology, patterns, rates of change, united-states, vegetation dynamics},
	isbn = {1432-9840},
	author = {Fuller, T. L.  and Foster, D. R.  and McLachlan, T. S.  and Drake, N.}
}
