Studies on Connecticut lake sediments; Part 1, A postglacial climatic chronolgy for southern New England

Deevey, Edward S.

doi:10.2475/ajs.237.10.691

Cited by 114 publications

(91 citation statements)

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“…These results suggested that the adult survivorship curve was slightly concave (Fig. 7), but still resembled a type-II survivorship curve (Deevey 1947). Assuming stationary population size, the calculated mean life expectancy for males was 1.89 breeding seasons; for females it was only 1.31 breeding seasons.…”

Section: :)mentioning

confidence: 96%

“…Despite the decline in per capita reproduction in SM over the 3-yr period, it was the only pond in which per capita reproduction was substantially above simple replacement, estimated to be 1.76 per female. Calculated from 1 = VXm, (Deevey 1947) this number is required for the average female to sustain a stationary, nongrowing population. I used my observed survivorship schedule for lx and back calculated for an average m. This calculation assumes no mortality during the eft stage, and therefore is a gross underestimate of the actual reproduction needed for replacement.…”

Section: Juvenile Productionmentioning

confidence: 99%

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The Metapopulation Ecology of the Red‐Spotted Newt, Notophthalmus viridescens (Rafinesque)

Gill¹

1978

Ecological Monographs

366

257

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecological Monographs.Abstract. The population dynamics and ecology of the red-spotted newt were studied from 1974 to the present in a series of mountain ponds in the Shenandoah Mountains, Virginia. Adult and juvenile newts were censused using a combination of methods, including drift fences and dip-netting. A technique of individual recognition was developed utilizing the number and pattern of dorsal red spots. Assisted by a simple system of toeclips, designating pond and year of first capture, these methods provided records of age, survival, and movements of >8,500 individuals.The results revealed 2 migratory peaks of adults each year: a breeding migration to ponds in March, and an August-September emigration to terrestrial hibernacula. Breeding population size, ranging from 6 to >2,600 adults per pond was stationary during the study but was significantly correlated with pond age. Annual turnover of breeding populations to new adults exceeded 50%. Sex ratios were consistently 2 6 6: I 9 in the breeding populations but tended toward 1:1 in the cohorts of new recruits. Annual adult 9 survival was density dependent and significantly less than that of 6 6 . The average 9 expected to breed only 1.3 times, whereas 6 6 had an expectancy of 1.9 breeding seasons. Faithfully homing to the same pond year after year, adults never migrated to new ponds between breeding seasons.Juvenile production at most ponds was poor over the 3 yr. Only I pond had a reproductive output consistently above a calculated replacement rate. It is inferred from the combination of poor reproduction and high immigration rates that breeding adults were not replaced by their own progeny but rather by foreign-born individuals.The red-spotted newt is basically a colonizing species responding to pond habitats that rapidly shift in time and space. It is suggested that beaver ponds have the necessary attributes of small size and temporal instability to which the life-history patterns of newts seems adapted. The majority of ponds in this area functioned as reproductive sinks in a larger, metapopulational structure. Adults in such ponds were reproductive failures for most of their lives. Only a small number of adults accounted for the regional reproduction in 1974 and 1975, but I very populous pond produced >91% of the young in 1976. Because reproductive success is pond dependent, interdemal selection may play an important role in newt evolution. It is hypothesized that homing behavior evolved as a consequence of natural selection within metapopulation centers and that the eft stage is the mechanism of dispersability to new...

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Section: :)mentioning

confidence: 96%

Section: Juvenile Productionmentioning

confidence: 99%

The Metapopulation Ecology of the Red‐Spotted Newt, Notophthalmus viridescens (Rafinesque)

Gill¹

1978

Ecological Monographs

366

257

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“…First recognized in pollen sequences from New England (Deevey 1939), the Tsuga decline drew particular attention with Margaret Davis's synthesis and summary (Davis 1981), in which she observed that the decline was apparently synchronous across the entire species range. In an elegant application of ''strong inference'' (Chamberlin 1890, Platt 1964) to paleoecology, Davis argued that the event was caused by a pest or pathogen outbreak by evaluating and rejecting a series of alternative hypotheses and by drawing analogies to the 20th century pathogen-driven Castanea and Ulmus declines in the same region (Davis 1981, Allison et al 1986.…”

Section: Introductionmentioning

confidence: 99%

Decomposing the mid‐Holocene Tsuga decline in eastern North America

Booth

Brewer

Blaauw

et al. 2012

Ecology

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Abstract. The mid-Holocene decline of Tsuga canadensis (hereafter Tsuga) populations across eastern North America is widely perceived as a synchronous event, driven by pests/ pathogens, rapid climate change, or both. Pattern identification and causal attribution are hampered by low stratigraphic density of pollen-sampling and radiometric dates at most sites, and by absence of highly resolved, paired pollen and paleoclimate records from single sediment cores, where chronological order of climatic and vegetational changes can be assessed. We present an intensely sampled (contiguous 1-cm intervals) record of pollen and water table depth (inferred from testate amoebae) from a single core spanning the Tsuga decline at Irwin Smith Bog in Lower Michigan, with high-precision chronology. We also present an intensively sampled pollen record from Tower Lake in Upper Michigan. Both sites show high-magnitude fluctuations in Tsuga pollen percentages during the pre-decline maximum. The terminal decline is dated at both sites ca. 5000 cal yr BP, some 400 years later than estimates from other sites and data compilations. The terminal Tsuga decline was evidently heterochronous across its range. A transient decline ca. 5350 cal yr BP at both sites may correspond to the terminal decline at other sites in eastern North America. At Irwin Smith Bog, the terminal Tsuga decline preceded an abrupt and persistent decline in water table depths by ;200 years, suggesting the decline was not directly driven by abrupt climate change. The Tsuga decline may best be viewed as comprising at least three phases: a long-duration predecline maximum with high-magnitude and high-frequency fluctuations, followed by a terminal decline at individual sites, followed in turn by two millennia of persistently low Tsuga populations. These phases may not be causally linked, and may represent dynamics taking place at multiple temporal and spatial scales. Further progress toward understanding the phenomenon requires an expanded network of high-resolution pollen and paleoclimate chronologies.

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“…To our knowledge, all pollen counts have been done by LM. First noted in Connecticut by Deevey (1939), a pest or pathogen driven decline was suggested by Davis (1981) and Bhiry and Filion (1996), but more recent support is given for a climate driver of the decline (Haas & McAndrews 2000;Foster et al 2006;Shuman et al 2009;Oswald & Foster 2011). An assumed synchronous decline estimated from 60 sites across North America was dated at 5500 cal BP by Bennett and Fuller (2002).…”

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confidence: 94%

A pollen profile by scanning electron microscopy bracketing the mid-HoloceneTsuga canadensisdecline at Poutwater Pond Bog, Holden, Massachusetts

Smyth

Seales

Bradley

2015

Grana

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Studies on Connecticut lake sediments; Part 1, A postglacial climatic chronolgy for southern New England

Cited by 114 publications

References 0 publications

The Metapopulation Ecology of the Red‐Spotted Newt, Notophthalmus viridescens (Rafinesque)

The Metapopulation Ecology of the Red‐Spotted Newt, Notophthalmus viridescens (Rafinesque)

Decomposing the mid‐Holocene Tsuga decline in eastern North America

A pollen profile by scanning electron microscopy bracketing the mid-HoloceneTsuga canadensisdecline at Poutwater Pond Bog, Holden, Massachusetts

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