scholarly journals Savanna canopy trees under fire: long‐term persistence and transient dynamics from a stage‐based matrix population model

Ecosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Patricia A. Werner ◽  
Stephanie J. Peacock
Keyword(s):  
Population Model ◽  
Transient Dynamics ◽  
Matrix Population Model ◽  
Canopy Trees

scholarly journals Estimation of the density of the Near Threatened jaguar Panthera onca in Sonora, Mexico, using camera trapping and an open population model

Oryx ◽  
2012 ◽  
Vol 46 (3) ◽  
pp. 431-437 ◽  
Author(s):  
Carmina E. Gutiérrez-González ◽  
Miguel Á. Gómez-Ramírez ◽  
Carlos A. López-González
Keyword(s):  
Population Model ◽  
Panthera Onca ◽  
Invasive Grass ◽  
Natural Area ◽  
Open Population ◽  
Apparent Relationship ◽  
Protected Natural Area ◽  
Arid Habitat ◽  
The Impact

AbstractOur objective in this study was to determine the density of the jaguar Panthera onca from camera-trap data, using an open population model, in a private protected natural area, the Northern Jaguar Reserve, and 10 adjoining cattle ranches in the state of Sonora, Mexico. The region is considered a long–term jaguar conservation unit. As well as being the most northerly recorded reproductive population of the jaguar, the arid habitat of this region is atypical for the species. During 16 months of sampling we identified 10 individual jaguars and the data met the three main assumptions of open population models. The estimated mean density was 1.05±SE 0.4 individuals per 100 km2, with a constant survival probability of 0.94 and capture probability of 0.23. This estimate of density is lower than reported in studies of the jaguar from more southerly locations in Mexico, Belize, Costa Rica, Bolivia and Brazil but cannot be attributed to a single factor even though in general there is an apparent relationship between jaguar density and precipitation. The main objectives of the management of the Northern Jaguar Reserve are to reduce the impact of cattle and restore jaguar habitat, with strategies focused on water retention, removal of invasive grass, reforestation and environmental education. Livestock have been gradually excluded since 2003 and, combined with the protection provided under the agreements with the surrounding ranches, the area is now a suitable place for long-term studies of the jaguar.

scholarly journals Short-Term Effects of Silvicultural Treatments on Microsite Heterogeneity and Plant Diversity in Mature Tennessee Oak-Hickory Forests

2006 ◽  
Vol 23 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Samuel W. Jackson ◽  
Craig A. Harper ◽  
David S. Buckley ◽  
Bradley F. Miller
Keyword(s):  
Soil Moisture ◽  
Plant Diversity ◽  
Prescribed Burning ◽  
Canopy Cover ◽  
First Year ◽  
Herbaceous Plant ◽  
Silvicultural Treatments ◽  
Canopy Trees ◽  
Microsite Heterogeneity

Abstract Growing emphasis on sustainability has increased the demand for information on effects of forest management on species diversity. We investigated the hypothesis that plant diversity is a function of microsite heterogeneity by documenting plant diversity and heterogeneity in canopy cover, light, and soil moisture produced by four silvicultural treatments during the first growing season following treatment: prescribed burning, wildlife retention cut with prescribed burning, wildlife retention cut, and shelterwood cutting. Treatments and controls were randomly assigned within four relatively undisturbed, 70–90-year-old oak-hickory stands. Heterogeneity in canopy cover and photosynthetically active radiation was greatest after shelterwood cutting, whereas the wildlife retention cut resulted in less removal of canopy trees and a smaller increase in heterogeneity of these factors. The addition of prescribed burning enhanced the effects of the wildlife retention cut. Prescribed burning alone had the least impact on heterogeneity of these factors. Soil moisture variability appeared to be independent of treatments. Shelterwood cutting increased first-year herbaceous plant diversity, and this increase was likely due, in part, to increased heterogeneity in canopy cover, light, and seedbed condition. These first-year results partially support the hypothesis that plant diversity is a function of microsite diversity in these forests. Long-term monitoring is underway.

Long-term management of the parasitic weed Striga hermonthica: Strategy evaluation with a population model

2007 ◽  
Vol 26 (3) ◽  
pp. 219-227 ◽  
Author(s):  
P.R. Westerman ◽  
A. van Ast ◽  
T.J. Stomph ◽  
W. van der Werf
Keyword(s):  
Population Model ◽  
Striga Hermonthica ◽  
Parasitic Weed ◽  
Strategy Evaluation ◽  
Term Management

scholarly journals Application of a Systems Pharmacology‐Based Placebo Population Model to Analyze Long‐Term Data of Postmenopausal Osteoporosis

2015 ◽  
Vol 4 (9) ◽  
pp. 516-526 ◽  
Author(s):  
J Berkhout ◽  
JA Stone ◽  
KM Verhamme ◽  
BH Stricker ◽  
MC Sturkenboom ◽  
...  
Keyword(s):  
Postmenopausal Osteoporosis ◽  
Population Model ◽  
Systems Pharmacology ◽  
Term Data

scholarly journals Game theoretic methods in population dynamics

2016 ◽  
Author(s):  
David Liao
Keyword(s):  
Cell Interaction ◽  
Transient Dynamics ◽  
Computational Techniques ◽  
Cellular Phenotype ◽  
Biopsy Specimens ◽  
Individual Based Models ◽  
Game Theoretic ◽  
Simple Systems ◽  
Heterogeneous Tissues

AbstractGame theoretic methods are used to model the dynamics of cellular populations (tissues) in which it is necessary to account for changes in cellular phenotype (usually proliferation) resulting from cell-cell interaction. Results include prediction of long-term steady-state “equilibria” and transient dynamics. These results can be useful for predicting relapse after cytoreduction, assessing the efficacy of alternating combination therapy, and interpreting biopsy specimens obtained from spatially heterogeneous tissues. Mathematical tools range from simple systems of differential equations to computational techniques (individual-based models).

scholarly journals Polar bear hunt strategies evaluated by a Leslie matrix population model

1983 ◽  
Vol 1 (3) ◽  
pp. 241-247
Author(s):  
Nils Are Øritsland ◽  
Ray Schweinsburg
Keyword(s):  
Population Model ◽  
Polar Bear ◽  
Leslie Matrix ◽  
Matrix Population Model

scholarly journals The genealogical decomposition of a matrix population model with applications to the aggregation of stages

2016 ◽  
Author(s):  
François Bienvenu ◽  
Erol Akçay ◽  
Stéphane Legendre ◽  
David M. McCandlish
Keyword(s):  
Population Model ◽  
Population Biology ◽  
Projection Matrix ◽  
Dominant Eigenvalue ◽  
Matrix Population Model ◽  
Ergodic Markov Chain ◽  
Number Of Classes ◽  
The Relationship ◽  
Asymptotic Growth Rate ◽  
Central Tool

AbstractMatrix projection models are a central tool in many areas of population biology. In most applications, one starts from the projection matrix to quantify the asymptotic growth rate of the population (the dominant eigenvalue), the stable stage distribution, and the reproductive values (the dominant right and left eigenvectors, respectively). Any primitive projection matrix also has an associated ergodic Markov chain that contains information about the genealogy of the population. In this paper, we show that these facts can be used to specify any matrix population model as a triple consisting of the ergodic Markov matrix, the dominant eigenvalue and one of the corresponding eigenvectors. This decomposition of the projection matrix separates properties associated with lineages from those associated with individuals. It also clarifies the relationships between many quantities commonly used to describe such models, including the relationship between eigenvalue sensitivities and elasticities. We illustrate the utility of such a decomposition by introducing a new method for aggregating classes in a matrix population model to produce a simpler model with a smaller number of classes. Unlike the standard method, our method has the advantage of preserving reproductive values and elasticities. It also has conceptually satisfying properties such as commuting with changes of units.

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