Partial Life-Cycle Analysis: A Model for Birth-Pulse Populations

Oli, Madan K.; Zinner, Bertram

doi:10.1890/0012-9658(2001)082[1180:plcaam]2.0.co;2

Cited by 31 publications

(46 citation statements)

References 29 publications

(53 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar approaches, so called 'partial life cycle analyses' are often used when part of the age-specific estimates are lacking (Oli and Zinner 2001, Oli 2003, Dillingham 2010. Since in the present study we specifically aimed at investigating the effects of climate, fishing and the spawning properties on a partial demography dependent on age-specific rates (survival and the maturity), we assume the ratio R t /N spawners,t1 was constant over time.…”

Section: Modeling Approachmentioning

confidence: 99%

Context‐dependent interplays between truncated demographies and climate variation shape the population growth rate of a harvested species

et al. 2011

View full text Add to dashboard Cite

Fisheries ecologists traditionally aimed at disentangling climate and fishing effects from the population dynamics of exploited marine fish stocks. However, recent studies have shown that internal characteristics and external forcing (climate and exploitation) have interactive rather than additive effects. Thought most of these studies explored how demographic truncation induced by exploitation affected the response of recruitment to climate, identifying a general pattern revealed to be difficult as interactions are often case-specific. Here we compared five exploited stocks of European hake Merluccius merluccius from the Atlantic Ocean and Mediterranean Sea to investigate how the interaction between internal characteristics and external forces affect the variability of the population growth rate and their consequences on recruitment. Our results show that demographic truncation induces a novel population scenario in which the growth rate is maximized when the reproductive stock is younger and less diverse. This scenario is shaped by the climate variability and the fishing pattern. The population growth rate becomes more dependent on the maturation schedule and less on the survival rates. The consequences for the recruitment dynamics are twofold; the effect of density-dependent regulatory processes decreases while the effect of the density-independent drivers increases. Our study shows that the interaction between internal characteristics and external forces changes across geographic locations according to 1) the importance of demographic truncation, 2) the influence of the climate on the regional hydrography and 3) the spatiotemporal heterogeneity of the physical environment to which fish life history is adapted.

show abstract

Section: Modeling Approachmentioning

confidence: 99%

Context‐dependent interplays between truncated demographies and climate variation shape the population growth rate of a harvested species

et al. 2011

View full text Add to dashboard Cite

show abstract

“…One of the strengths of PLC is that the form of the characteristic equation allows exploration of model sensitivity to parameters not appearing in Leslie models (i.e. age at maturity and lifespan; Oli and Zinner 2001a). In fact, partial life cycle models are rooted in life history analysis of effects of age at maturity on individual fitness (Cole 1954, Stearns and Crandall 1984).…”

Section: Discussionmentioning

confidence: 99%

“…In order to explore effects of theoretical life history variation on partial life cycle analyses, we used the matrix form of the partial life cycle model (Oli and Zinner 2001a), denoted with the PLC subscript: where n t is the population vector at time t. Construction of this model requires estimates of F A , P J , and P A . Also required are age at maturity (α) and longevity (ω), which are implicit in the structure of the matrix model.…”

Section: Methodsmentioning

confidence: 99%

“…The full Leslie matrix models in Oli's analysis were taken directly from the literature or derived from published and occasionally sparse life table data. The method of reducing these matrices to the PLC involves the use of weighted averages for both juvenile and adult stages (Oli and Zinner 2001a). For example, juvenile survival (P J ) in the PLC was taken as the mean of survival rates for all pre‐reproductive age classes, each of which being weighted by its corresponding contribution to the stable age distribution (i.e.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Bias in population growth rate estimation: sparse data, partial life cycle analysis and Jensen's inequality

Grear¹,

Elderd²

2008

Oikos

View full text Add to dashboard Cite

Demographic matrix models have become an integral part of population viability analysis for threatened and endangered species, but their use is often limited by data availability. A common solution to this problem is to assume constant annual rates within a multi-year stage. Partial life cycle analysis (PLC), which incorporates only juvenile and adult stages, is a noteworthy example of this approach because it has been described in the literature as a reliable approximation of agestructured populations. However, we predict from Jensen's Inequality that the required lumping of age classes leads to over-or underestimation of population fitness when survival rates are truly age-dependent. We illuminate this problem by comparing fitness estimates from Leslie matrix and PLC models for theoretical populations having different levels of age-dependence in their survival rates. We also propose a modification of the PLC approach to address this problem and demonstrate its applicability using data from a published long-term study of red deer Cervus elephas.

show abstract

“…First, we compared the realized growth rate (r) with the capability of a population to grow independent of the recruitment success variability. To do that, recruitment-independent growth rate (r RI ) was calculated using a ''partial life cycles analyses'' (i.e., demographic models in which part of the age-specific estimates are lacking, e.g., Oli and Zinner [2001]). In these analyses, the reproductive rate was replaced by Mat in the Leslie matrix with recruitment success remaining at a constant value of 1 for the whole study period.…”

Section: Population Dynamics Consequencesmentioning

confidence: 99%

Contrasting evolutionary demography induced by fishing: the role of adaptive phenotypic plasticity

Hidalgo

Olsen

Ohlberger

et al. 2014

Ecological Applications

View full text Add to dashboard Cite

Mounting evidence now shows that fishing activity modifies both heritable life-history traits and ecological processes in harvested populations. However, ecological and evolutionary changes are intimately linked and can occur on the same time scale, and few studies have investigated their combined effect on fish population dynamics. Here, we contrast two population subunits of a harvested fish species in the Northeast Atlantic, the European hake (Merluccius merluccius), in the light of the emerging field of evolutionary demography, which considers the interacting processes between ecology and evolution. The two subunits experienced similar age/size truncation due to size-selective fishing, but displayed differences in key ecological processes (recruitment success) and phenotypic characteristics (maturation schedule). We investigate how temporal variation in maturation and recruitment success interactively shape the population dynamics of the two subunits. We document that the two subunits of European hake displayed different responses to fishing in maturation schedules, possibly because of the different level of adaptive phenotypic plasticity. Our results also suggest that high phenotypic plasticity can dampen the effects of fisheries-induced demographic truncation on population dynamics, whereas a population subunit characterized by low phenotypic plasticity may suffer from additive effects of ecological and life-history responses. Similar fishing pressure may thus trigger contrasting interactions between life history variation and ecological processes within the same population. The presented findings improve our understanding of how fishing impacts eco-evolutionary dynamics, which is a keystone for a more comprehensive management of harvested species.

show abstract

Partial Life-Cycle Analysis: A Model for Birth-Pulse Populations

Cited by 31 publications

References 29 publications

Context‐dependent interplays between truncated demographies and climate variation shape the population growth rate of a harvested species

Context‐dependent interplays between truncated demographies and climate variation shape the population growth rate of a harvested species

Bias in population growth rate estimation: sparse data, partial life cycle analysis and Jensen's inequality

Contrasting evolutionary demography induced by fishing: the role of adaptive phenotypic plasticity

Contact Info

Product

Resources

About