We consider the harvesting of a population in a stochastic environment whose dynamics in the absence of harvesting are described by the logistic Verhulst-Pearl model. Using ergodic optimal control, we find the optimal harvesting strategy which maximizes the asymptotic yield of harvested individuals. To our knowledge, ergodic optimal control has not been used before to study harvesting strategie...

This paper deals with a delayed ratio-dependent functional response predator-prey model with a threshold harvesting policy. We study the equilibria of the system before and after the threshold. We show that the threshold harvesting can improve the undesirable behavior such as nonexistence of interior equilibria. The global analysis of the model as well as boundedness and permanence properties a...

this paper deals with a delayed ratio-dependent functional response predator-prey model with a threshold harvesting policy. we study the equilibria of the system before and after the threshold. we show that the threshold harvesting can improve the undesirable behavior such as nonexistence of interior equilibria. the global analysis of the model as well as boundedness and permanence properties a...

It was recently shown that the nonlinear logistic type ODE with periodic harvesting has a bifurcation on the periodic solutions with respect to the parameter : u′ = f(u)− h(t). Namely, there exists an 0 such that for 0 < < 0 there are two periodic solutions, for = 0 there is one periodic solution, and for > 0 there are no periodic solutions, provided that ∫ T 0 h(t)dt > 0. In this paper we look...

We use a Wicksellian single rotation framework to analyze the impact of the intertemporally fluctuating and stochastic mean-reverting interest rate process on the optimal harvesting threshold and thereby the expected length of the rotation period, when forest value is also stochastic following geometric Brownian motion and landowners are risk-averse. We provide an explicit solution for the two-...

Routing under energy harvesting constraints is considered. A routing protocol based on Dijkstra’s global routing algorithm is proposed and evaluated. The protocol dynamically modifies routing trees based on available energy accumulated through energy harvesting. Channel-state information is gathered in typical indoor environments using two experimental setups; one with eight nodes and on-body a...

Wildflower harvesting is an economically important activity of which the ecological effects are poorly understood. We assessed how harvesting of flowers affects shrub persistence and abundance at multiple spatial extents. To this end, we built a process-based model to examine the mean persistence and abundance of wild shrubs whose flowers are subject to harvest (serotinous Proteaceae in the Sou...

As the use of forest harvesting residues for energy production gains popularity, debate continues regarding the long-term sustainability of whole tree harvesting (WTH). This practice removes nutrient-rich twigs that only account for a small fraction of harvest residues, emphasising the need to develop nutrient-efficient alternatives to WTH. This study assessed N, P, K, Ca, and Mg distributions ...

Harvesting strategies in a fish stock dominated by low-frequency variability: The Norwegian spring-spawning herring (Clupea harengus). Marine Resource Economics 18: 263–274. Enberg, K. 2005. Benefits of threshold strategies coupled with age-selective harvesting in a highly variable fish stock: Norwegian spring-spawning herring (Clupea harengus) as an example. Marine Ecology Progress Series, in ...