Effects of delay, truncations and density dependence in reproduction schedules on stability of nonlinear Leslie matrix models

1993 ◽  
Vol 31 (4) ◽  
pp. 367-395 ◽  
Author(s):  
Jacques A. L. Silva ◽  
Thomas G. Hallam
Keyword(s):  
Density Dependence ◽  
Matrix Models ◽  
Leslie Matrix ◽  
Nonlinear Leslie Matrix Models

Diagnosing declining grassland wader populations using simple matrix models

2009 ◽  
Vol 59 (1) ◽  
pp. 127-144 ◽  
Author(s):  
Lia Hemerik ◽  
Chris Klok ◽  
Maja Roodbergen
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Matrix Models ◽  
Population Growth Rate ◽  
Adult Stage ◽  
Demographic Data ◽  
Leslie Matrix ◽  
Adult Survival ◽  
Demographic Parameters ◽  
Survival And Reproduction

AbstractMany populations of wader species have shown a strong decline in number in Western-Europe in recent years. The use of simple population models such as matrix models can contribute to conserve these populations by identifying the most profitable management measures. Parameterization of such models is often hampered by the availability of demographic data (survival and reproduction). In particular, data on survival in the pre-adult (immature) stage of wader species that remain in wintering areas outside Europe are notoriously difficult to obtain, and are therefore virtually absent in the literature. To diagnose population decline in the wader species; Black-tailed Godwit, Curlew, Lapwing, Oystercatcher, and Redshank, we extended an existing modelling framework in which incomplete demographic data can be analysed, developed for species with a pre-adult stage of one year. The framework is based on a Leslie matrix model with three parameters: yearly reproduction (number of fledglings per pair), yearly pre-adult (immature) and yearly adult (mature) survival. The yearly population growth rate of these populations and the relative sensitivity of this rate to changes in survival and reproduction parameters (the elasticity) were calculated numerically and, if possible, analytically. The results showed a decrease in dependence on reproduction and an increase in pre-adult survival of the population growth rate with an increase in the duration of the pre-adult stage. In general, adult survival had the highest elasticity, but elasticity of pre-adult survival increased with time to first reproduction, a result not reported earlier. Model results showed that adult survival and reproduction estimates reported for populations of Redshank and Curlew were too low to maintain viable populations. Based on the elasticity patterns and the scope for increase in actual demographic parameters we inferred that conservation of the Redshank and both Curlew populations should focus on reproduction. For one Oystercatcher and the Black-tailed Godwit populations we suggested a focus on both reproduction and pre-adult survival. For the second Oystercatcher population pre-adult survival seemed the most promising target for conservation. And for the Lapwing populations all demographic parameters should be considered.

Consequences of potential density-dependent mechanisms on recovery of ocean-type chinook salmon (Oncorhynchus tshawytscha)

2004 ◽  
Vol 61 (4) ◽  
pp. 590-602 ◽  
Author(s):  
Correigh M Greene ◽  
Timothy J Beechie
Keyword(s):  
Density Dependence ◽  
Chinook Salmon ◽  
Habitat Restoration ◽  
Oncorhynchus Tshawytscha ◽  
High Sensitivity ◽  
Leslie Matrix ◽  
Relative Importance ◽  
Density Dependent ◽  
Habitat Area ◽  
Leslie Matrix Model

Restoring salmon populations depends on our ability to predict the consequences of improving aquatic habitats used by salmon. Using a Leslie matrix model for chinook salmon (Oncorhynchus tshawytscha) that specifies transitions among spawning nests (redds), streams, tidal deltas, nearshore habitats, and the ocean, we compared the relative importance of different habitats under three density-dependent scenarios: juvenile density independence, density-dependent mortality within streams, delta, and nearshore, and density-dependent migration among streams, delta, and nearshore. Each scenario assumed density dependence during spawning. We examined how these scenarios influenced priorities for habitat restoration using a set of hypothetical watersheds whose habitat areas could be systematically varied, as well as the Duwamish and Skagit rivers. In all watersheds, the three scenarios shared high sensitivity to changes in in nearshore and ocean mortality and produced similar responses to changes in other parameters controlling mortality (i.e., habitat quality). However, the three scenarios exhibited striking variation in population response to changes in habitat area (i.e., capacity). These findings indicate that nearshore habitat relationships may play significant roles for salmon populations and that the relative importance of restoring habitat area will depend on the mechanism of density dependence influencing salmon stocks.

Analysis of compensatory Leslie matrix models for competing species

1980 ◽  
Vol 18 (1) ◽  
pp. 16-30 ◽  
Author(s):  
C.C. Travis ◽  
W.M. Post ◽  
D.L. DeAngelis ◽  
J. Perkowski
Keyword(s):  
Matrix Models ◽  
Leslie Matrix ◽  
Competing Species

scholarly journals The winner takes it all: how semelparous insects can become periodical

2018 ◽  
Author(s):  
Odo Diekmann ◽  
Robert Planqué
Keyword(s):  
Density Dependence ◽  
Initial Conditions ◽  
Short Note ◽  
Leslie Matrix ◽  
Positive Density ◽  
Simple Explanation ◽  
Large Classes ◽  
Full Life Cycle ◽  
Positive Density Dependence ◽  
One Year

AbstractThe aim of this short note is to give a simple explanation for the remarkable periodicity of Magicicada species, which appear as adults only every 13 or 17 years, depending on the region. We show that a combination of two types of density dependence may drive, for large classes of initial conditions, all but one year class to extinction. Competition for food leads to negative density dependence in the form of a uniform (i.e., affecting all age classes in the same way) reduction of the survival probability. Satiation of predators leads to positive density dependence within the reproducing age class. The analysis focuses on the full life cycle map derived by iteration of a semelparous Leslie matrix.

365: Leslie Matrix Models for Fisheries Studies

Biometrics ◽  
1974 ◽  
Vol 30 (3) ◽  
pp. 547 ◽  
Author(s):  
A. L. Jensen
Keyword(s):  
Matrix Models ◽  
Leslie Matrix
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