Effects of life history and reproduction on recruitment time lags in reintroductions of rare plants

2019 ◽  
Vol 33 (3) ◽  
pp. 601-611 ◽  
Author(s):  
Matthew A. Albrecht ◽  
Oyomoare L. Osazuwa‐Peters ◽  
Joyce Maschinski ◽  
Timothy J. Bell ◽  
Marlin L. Bowles ◽  
...  
Keyword(s):  
Life History ◽  
Rare Plants ◽  
Time Lags ◽  
Recruitment Time

scholarly journals Estimating density dependence in time–series of age–structured populations

2002 ◽  
Vol 357 (1425) ◽  
pp. 1179-1184 ◽  
Author(s):  
R. Lande ◽  
S. Engen ◽  
B.–E. Sæther
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Life History ◽  
Density Dependence ◽  
Population Size ◽  
Adult Population ◽  
Structured Populations ◽  
Total Density ◽  
Time Lags ◽  
Long Time

For a life history with age at maturity α, and stochasticity and density dependence in adult recruitment and mortality, we derive a linearized autoregressive equation with time–lags of from 1 to α years. Contrary to current interpretations, the coefficients for different time–lags in the autoregressive dynamics do not simply measure delayed density dependence, but also depend on life–history parameters. We define a new measure of total density dependence in a life history, D , as the negative elasticity of population growth rate per generation with respect to change in population size, D = –∂lnλ T /∂ln N , where λ is the asymptotic multiplicative growth rate per year, T is the generation time and N is adult population size. We show that D can be estimated from the sum of the autoregression coefficients. We estimated D in populations of six avian species for which life–history data and unusually long time–series of complete population censuses were available. Estimates of D were in the order of 1 or higher, indicating strong, statistically significant density dependence in four of the six species.

Demography and life history of three sympatric species of Botrychium subg. Botrychium in Waterton Lakes National Park, Alberta

1996 ◽  
Vol 74 (4) ◽  
pp. 538-543 ◽  
Author(s):  
Peter Lesica ◽  
Kathleen Ahlenslager
Keyword(s):  
Life History ◽  
National Park ◽  
Natural Disturbance ◽  
Sympatric Species ◽  
Rare Plants ◽  
Permanent Plots ◽  
Population Sizes ◽  
Waterton Lakes National Park ◽  
Disturbed Habitats ◽  
Prolonged Dormancy

We followed the fate of mapped sporophytes of Botrychium paradoxum, Botrychium hesperium, and their hybrid Botrychium × watertonense in permanent plots for 6 years in Waterton Lakes National Park, Alberta. All three species had half-lives of approximately 3 years or less. Botrychium paradoxum had higher rates of recruitment and mortality leading to less stable population sizes than B. hesperium, perhaps contributing to the former's relative rarity. All species demonstrated prolonged dormancy whereby plants remain below ground for 1 or more years before reappearing. Surveys and monitoring studies for these and probably other species of Botrychium are more difficult owing to prolonged dormancy. Short lifespan and association with disturbed habitats suggests that these ferns may require natural disturbance regimes for long-term persistence. Keywords: Botrychium, demography, life history, rare plants, prolonged dormancy, Waterton Lakes National Park.

scholarly journals Demographic compensation does not rescue populations at a trailing range edge

2017 ◽  
Author(s):  
Seema Nayan Sheth ◽  
Amy Lauren Angert
Keyword(s):  
Climate Change ◽  
Life History ◽  
Population Growth ◽  
Growth Rates ◽  
Time Lags ◽  
Vital Rates ◽  
Low Latitude ◽  
Species Ranges ◽  
Population Growth Rates ◽  
Range Edge

ABSTRACTAs climate change shifts species' climatic envelopes across the landscape, equilibrium between geographic ranges and niches is likely diminishing due to time lags in demography and dispersal. If a species' range and niche are out of equilibrium, then population performance should decrease from cool, “leading” range edges, where populations are expanding into recently ameliorated habitats, to warm, “trailing” range edges, where populations are contracting from newly unsuitable areas. Population contraction signals that compensatory changes in vital rates are insufficient to buffer population growth from deteriorating environments. Life history theory predicts tradeoffs between fast development, high reproduction, and short longevity at low latitudes and slow development, less frequent but multiple bouts of reproduction, and long lifespan at high latitudes. If demographic compensation is driven by life history evolution, compensatory negative correlations in vital rates may be associated with this fast-slow continuum. An outstanding question is whether range limits and range contractions reflect inadequate compensatory life history shifts along environmental gradients, causing population growth rates to fall below replacement levels at range edges. We surveyed demography of 32 populations of the scarlet monkeyflower (Erythranthe cardinalis) spanning 11° latitude in western North America and used integral projection models to infer population dynamics and assess demographic compensation. Population growth rates decreased from north to south, consistent with leading-trailing dynamics. Southern populations are declining due to reduced survival, growth, and recruitment, despite compensatory increases in reproduction and faster life history characteristics, suggesting that demographic compensation will not rescue populations at the trailing range edge.SIGNIFICANCE STATEMENTWhile climate change is causing poleward shifts in many species' geographic distributions, some species' ranges have remained stable, particularly at low-latitude limits. One explanation for why some species' ranges have not shifted is demographic compensation, whereby declines in some demographic processes are offset by increases in others, potentially buffering populations from extinction. However, we have limited understanding of whether demographic compensation can prevent collapse of populations facing climate change. We examined the demography of natural populations of a perennial herb spanning a broad latitudinal gradient. Despite increases in reproduction, low-latitude populations declined due to diminished survival, growth, and recruitment. Thus, demographic compensation may not be sufficient to rescue low-latitude, warm-edge populations from extinction.

Interrelationships of factors of social development are more complex than Life History Theory predicts

2019 ◽  
Vol 42 ◽  
Author(s):  
Boris Kotchoubey
Keyword(s):  
Life History ◽  
Social Development ◽  
Life History Theory ◽  
Strong Correlations ◽  
Behavioral Features

Abstract Life History Theory (LHT) predicts a monotonous relationship between affluence and the rate of innovations and strong correlations within a cluster of behavioral features. Although both predictions can be true in specific cases, they are incorrect in general. Therefore, the author's explanations may be right, but they do not prove LHT and cannot be generalized to other apparently similar processes.

New data on the life history and ecology of the deep-sea hooked squid Taningia danae

Sarsia ◽  
2003 ◽  
Vol 88 (4) ◽  
pp. 297-301 ◽  
Author(s):  
Guerra A. ◽  
Rocha F. ◽  
A. F. González
Keyword(s):  
Life History ◽  
Deep Sea
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