103 research outputs found
Stage-Structured Periodic Population Model for the Florida Leafwing
The Florida leafwing is an endemic butterfly which is distributed in
South Florida and the lower Keys. Stage-structured population models are a useful
tool for the management and conservation of Florida leafwing. In this work we use
a discrete-time periodic control system for describing a leafwing population. One
of the main differences between this model and classical stage-structured models
is that in the current model we can alter the number of adults contributing to
eggs production. This allows us to control the population. The solution of the
problem is obtained using invariant formulations of positive periodic systems.Coll, C.; Horvitz, CC.; Mcelderry, R. (2012). Stage-Structured Periodic Population Model for the Florida Leafwing. International Journal of Complex Systems in Science. 2(1):1-5. http://hdl.handle.net/10251/80716S152
Conserving slow-growing, long-lived tree species: Input from the demography of a rare understory conifer, Taxus floridana
Although land preservation and promotion of successful regeneration are important conservation actions, their ability to increase population growth rates of slow-growing, long-lived trees is limited. We investigated the demography of Taxus floridana Nutt., a rare understory conifer, in three populations in different ravine forests spanning its entire geographic range along the Apalachicola River Bluffs in northern Florida (U.S.A.). We examined spatial and temporal patterns in demographic parameters and projected population growth rates by using four years of data on the recruitment and survival of seedlings and established stems, and on diameter growth from cross-sections of dead stems. All populations experienced a roughly 10-fold increase in seedling recruitment in 1996 compared with other years. The fates of seedlings and stems between 8 and 16 mm differed among populations. The fates of stems in two other size classes (the 2- to 4-mm class and the 4- to 8-mm class) differed among both populations and years. Individual stems in all populations exhibited similarly slow growth rates. Stochastic matrix models projected declines in all populations. Stochastic matrix analysis revealed the high elasticity of a measure of stochastic population growth rate to perturbations in the stasis of large reproductive stems for all populations. Additional analyses also indicated that occasional episodes of high recruitment do not greatly affect population growth rates. Conservation efforts directed at long-lived, slow-growing rare plants like Taxus floridana should both protect established reproductive individuals and further enhance survival of individuals in other life-history stages, such as juveniles, that often do not appear to contribute greatly to population growth rates
dorsalis
Data for Cephaloleia dorsalis (Chrysomelidae) from: Jack of all trades masters novel host plants: positive genetic correlations in specialist and generalist insect herbivores expanding their diets to novel hosts, Garcia-Robledo, Carlos, Horvitz, Caro
dilaticollis
Data for Cephaloleia dilaticollis from: Jack of all trades masters novel host plants: positive genetic correlations in specialist and generalist insect herbivores expanding their diets to novel hosts, Garcia-Robledo, Carlos, Horvitz, Caro
belti
Data for Cephaloleia belti (Chrysomelidae) from: Jack of all trades masters novel host plants: positive genetic correlations in specialist and generalist insect herbivores expanding their diets to novel hosts, Garcia-Robledo, Carlos, Horvitz, Caro
placida
Data for Cephaloleia placida (Chrysomelidae) from: Jack of all trades masters novel host plants: positive genetic correlations in specialist and generalist insect herbivores expanding their diets to novel hosts, Garcia-Robledo, Carlos, Horvitz, Caro
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From stage to age in variable environments : Life expectancy and survivorship
Maximum photosynthetic capacity
Contains measured rates of photosynthesis (leaf area based) for a subset of individuals in the experiment. The estimates of stomatal conductance are included but were not used because they were not taken at stomatal equilibrium
Growth and survival data
Contains total leaf area and survival (status) data for all individuals in the experiment. Leaf area was used to estimate growth rates. There is additional information on morphology, such as number of leaves, height, circumference. This information was not published in this paper
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