We investigate a nonautonomous predator–prey model system with a Crowley–Martin functional response. We perform rigorous mathematical analysis and obtain conditions for (a) global attractivity and permanence in the form of integrals which improve the traditional conditions obtained by using bounds of involved parameters; and (b) the existence of periodic solutions applying continuation theorem from

We develop a modeling framework, based on discrete‐time dynamic optimization, to study the effect of legacy nutrient stores and soil nutrient dynamics on optimal nutrient management and agri‐environmental policy in crop production. Three alternative measures are studied to reduce nutrient loss: reduced fertilization, nonlegume catch crop cultivation and gypsum amendment. According to our results, landowner

The monthly precipitations obtained during 51 years of measurement in 24 stations of Soummam watershed in Algeria were analyzed to describe rainfall trends and aridity state of the area using statistical modeling. The choice of distribution laws was justified by comparing fitting results of different distributions laws used in literature reviews. Hence, the p values proved that Generalized Extreme

Taking advantage of the electrification strategy, Northwest China has made full use of its natural resources endowment, to develop renewable energy as the substitution of thermal power. To evaluate carbon dioxide (CO2) emissions from electric power sector, an extended Kaya identity equation and the Logarithmic mean Divisia index decomposition method are applied to Northwest China from 1998 to 2017

Industrial forestry in boreal regions increases fragmentation and may decrease the viability of some wildlife populations, particularly the woodland caribou, Rangifer tarandus caribou. Caribou protection often calls for changes in forestry practices, which may increase the cost and reduce the available timber supply. We present a linear programming model that assesses the trade‐off between habitat

We study pollution cleanup in the Ganges in Varanasi, India. Voters elect politicians and elected politicians decide how much pollution to clean up. Between the two time periods, there is an election. Politicians are sincere or insincere. The marginal cost of public funds measures how efficiently elected politicians transform tax receipts into pollution cleanup. Voters have identical per period utility

Regionalization approach is adopted to test the credibility of a newly developed, large‐scale, conceptual hydrological model, namely, satellite‐based hydrological model (SHM), under data‐scarce conditions. SHM has a modular structure. There are five modules: surface water module (SW), which uses natural resources conservation service‐curve number and Hargreaves equation; forest module (F), which uses

Natural resource managers use barriers to deter the movement of aquatic invasive species. Research and development of new invasive species barriers is often evaluated in pond and field scales using high‐resolution telemetry data. Telemetry data sets can be a rich source of data about fish movement and behavior but can be difficult to analyze due to the size of these data sets as well as their irregular

The study of water quality and the quantification of reserves and their variations according to natural and anthropogenic forcing is necessary to establish an adequate management plan for groundwater resources. For this purpose, a modeling approach is a useful tool that allows, after calibration phase and verification of simulation, and under different scenarios of forcing and operational changes,

Environmental variability has a strong influence on marine fish stocks. Thus, management and harvest policies based on deterministic indicators, such as maximum sustainable yield (MSY), may be inappropriate facing such uncertainties. In this study, we investigate the long‐term behavior of a single‐species fishery, whose stock is harvested by several fleets and affected by variability in the recruitment

With the development of social economy and the diversification of human needs there is conflict between different functions of cultivated land. In this study, a practical evaluating methodology, which is a three‐dimensional trade‐off model on multifunctionality of cultivated land was constructed, and it was applied to Panxi region of southwestern China. The following results were obtained. (a) From

Fisheries are characterized by variations in space and time. This study investigates the characteristics of seasonality in cod trawl fisheries in two distinct areas: the coast along the northern Norway and the high sea area of the Barents Sea. Catch per unit effort (CPUE) is used to proxy variation in stock abundance. A CPUE function has been estimated in the frequency‐domain framework, to detect the

Given the hydrological, social, and economic complexity of water resources, planning for evaluation of such resources is extremely challenging. The vulnerability and limitations of water resources in one hand, and the growing demand on the other hand necessitates integrated planning for resource protection. Accordingly, applying Smart partial least squares software for structural equation modeling

Swimmer's itch is an emerging disease caused by flatworm parasites that often use water birds as definitive hosts. When parasite larvae penetrate human skin they initiate localized inflammation that leads to intense itching. Concerns about this issue have been growing recently due to an apparent increase in the global occurrence of swimmer's itch and its subsequent impacts on recreational activities

Emerald ash borer (EAB), a wood‐boring insect native to Asia, was discovered near Detroit in 2002 and has spread and killed millions of ash trees throughout the eastern United States and Canada. EAB causes severe damage in urban areas where it kills high‐value ash trees that shade streets, homes, and parks and costs homeowners and local governments millions of dollars for treatment, removal, and replacement

Conflicting evidence exists supporting linear and nonlinear density‐dependent population growth when species have slow life histories. The Ricker (linear) and θ‐logistic (nonlinear) models are commonly used to analyze survey data for these species, but no evaluation has examined whether these hypotheses can be differentiated with field data. We conducted a simulation exploring effects from shape of

We address the management of invasive estuarine herbs providing some economic benefits and characterized by two modes of reproduction affecting the ecosystem. The study began by analyzing the stability of the plant dynamics using an approximate model resulting from the negligence of the seasonality in seedlings production. The optimal control seeks to find strategies with a minimal implementation cost

In the past few decades, considerable efforts have been made to model rainfall‐runoff and to predict the hydrological impacts of various factors using computer technology. The Environmental Protection Agency Storm Water Management Model (SWMM) has been proved to be a powerful tool which simulates the flow of watersheds with different characteristics. The SWMM model is a dynamic rainfall‐runoff simulation

Multiobjective optimization is increasingly used to assist decision‐making in forest management when multiple objectives are considered and conflict with each other. Since forest management problems may deal with combinatorial optimization, as the scale of a problem increases, the computation complexity increases exponentially beyond the practical use of exact methods. We propose a multiple‐objective

Flavescence dorée is a serious and incurable vine disease transmitted by an insect vector. Focusing on its spatial diffusion and on its control with pesticides, this paper investigates the private strategies of wine producers and their socially optimal counterparts. The socially optimal regulation has to address two externalities regarding private treatment decisions: (a) the insufficient consideration

Valuation of water in an aquifer depends on reliable information about the hydrologic conditions of an aquifer. Regions of depression emerge in an aquifer because groundwater cannot seamlessly flow between shallow and deep aquifer locations, and our analysis shows that the degree of lateral flow influences the value of the water in the aquifer. The assumption that groundwater declines uniformly over

Knowing the temporal and spatial variability of the probability of rainfall occurrence is indispensable for the planning and management of agricultural and agroindustrial activities. This study aims to evaluate the applicability of four cumulative distribution functions (CDFs; exponential, two‐parameter exponential, mixed exponential, and gamma) to estimate the probability of daily rainfall in the

In this paper, three fuzzy nonlinear mathematical models, corresponding to crisp models described in Devi and Gupta (2018), are formulated to study the comparative behavior of carbon dioxide concerning vegetation biomass in crisp and fuzzy environments. Logistic growth and regrowth of vegetation biomass are considered in the first two models, and delay is incorporated in the regrowth of vegetation

We examine spatial and temporal variability in normalized difference vegetation index (NDVI), snow cover and land surface temperature (LST) in Himachal Pradesh between 2001 and 2017 using Moderate Resolution Imaging Spectroradiometer (MODIS) datasets. Mann–Kendall trend tests and Sen's slope estimates indicate increasing NDVI trends during the postmonsoon period. Increasing snow cover trend is observed

A nonlinear dynamical system is developed in the proposed study to gain insight into the tribal‐forest system in the presence of unplanned development activities. Here, the system is comprised of densities of forest resources, tribal population, and development activities as dynamic variables. The realistic dynamics between the tribal population and forest resources is considered to be of modified

This paper considers pollination‐mutualism systems, including intermediary resources, which are represented by nectar for convenience. In the plant–nectar–pollinator system, we focus on the case in which the plant cannot persist without pollination and the pollinator can live independently. When nectar is assumed to rapidly approach a steady state, the plant–nectar–pollinator system can be described

Meteorological extreme events have a major impact on water resources, economic development, and ecosystem health. In this study, maximum precipitation and maximum temperature indices were derived for Isfahan province, in central Iran, over the historical (1992–2017) and future (2020–2100) periods. Precipitation and maximum temperature data from the REMO model under RCP4.5 scenario were used to investigate

This paper investigates the rich dynamics in a tritrophic food chain mathematical model, consisting of three species: prey, intermediate predators, and top predators. It is assumed that alternative food are supplied to intermediate predators in addition to feeding on prey. We consider a general Holling type response function and analyze the model. The existence and stability of six possible equilibrium

Natural resources are not infinitely resilient and should not be modeled as being such. Finitely resilient resources feature tipping points and history dependence. This paper provides a didactical discussion of mathematical methods that are needed to understand the optimal management of such resources: viscosity solutions of Hamilton–Jacobi–Bellman equations, the costate equation and the associated

We present a steady‐state threshold risk analysis framework for exploited populations following the Beverton–Holt recurrence. The Beverton–Holt model is widely applied in the assessment of species biomass and fitted to experimental data to obtain a suitable range of parameter values. To account for the uncertainty in these parameter values, such as the growth rate, we analyze the probability of the

Black‐tailed prairie dogs (Cynomys ludovicianus) are a keystone species of shortgrass and midgrass prairies, and they are essential for successful reintroduction efforts of endangered black‐footed ferrets (Mustela nigripes). Sylvatic plague extirpates black‐tailed prairie dog colonies. We present a model to determine optimal control methods to sustain a black‐tailed prairie dog colony against the plague

Food chain models with interactions between key species are useful tools for ecological conservation and economic sustainability in commercial fisheries. In this study, we build a food chain model coupled with optimal control theory and focus on the Black Sea anchovy population in the southern part of the Black Sea. Our objective is to find the optimal harvesting strategy that maximizes the discounted

The Trojan Y Chromosome strategy (TYC) is a promising eradication method for biological control of nonnative species. The strategy works by manipulating the sex ratio of a population through the introduction of supermales that guarantee male offspring. In the current study, we compare the TYC method with a pure harvesting strategy. We also analyze a hybrid harvesting model that mirrors the TYC strategy

We present a general‐equilibrium (GE) bioeconomic model of Utah's Great Salt Lake (GSL) ecosystem that tightly links the lake's ecosystem with its regional economy and attendant international trading partners, thereby enabling full identification of dynamic feedback effects in the presence of prolonged drought. The drought modeled here mimics a drying climate's impact on the lake's nutrient pool. We

This paper investigates the effects of population, investment, urbanization, industrial structure, policy instrument, and enterprise size on energy intensity in Guangdong, China. A dynamic optimal theoretical framework is utilized and empirical results are reported using panel data from 2006 to 2015. The fixed effects models and spatial fixed effects models both show that population, investment, urbanization

In real‐world wetland vegetation morphology (WVM) detection, large scene variations such as those due to landform, vegetation, sunlight, weather, and sky, as well as camera parameter settings such as focal length and shooting angle, require systematic and complicated artificial intelligence technology to accurately discriminate inter and intra‐class wetland objections. To deal with these challenges

This paper deals with sustainability criteria and standards. The maximin criterion, as the highest performance that can be sustained over time, promotes intergenerational equity, a pivotal issue for sustainability. The viable control approach, by investigating trajectories and actions complying over time with various standards and constraints, provides major insights into strong sustainability. The

We examine the role of support for coalition stability in common pool resource games such as fisheries games. Some players may not want to join a coalition that jointly manages a resource. Still, because they benefit from spillovers, they may want to support the coalition with a transfer payment to set incentives for others to join. We find that the impact of support on equilibria of this game is limited

That numerous rural laborers migrate to urban areas to find off‐farm jobs has become an outstanding economic phenomenon in China. To examine the impact of rural labor off‐farm employment on household forest management, we built binary logistic models and Tobit models by applying a sample survey data of 500 households in rural Jiangxi in 2018. Households’ participation and investment in forest management

The theory of syndemics has been widely applied in HIV prevention studies of gay, bisexual, and other MSM over the last decade. Our investigation is the first to consider the applicability of the theory in a sample of aging (ages 50 and over) HIV-positive MSM, which is a growing population in the United States. A sample of 199 men were actively recruited and assessed in terms of mental health and drug

Exploiting a rich data set including both individual fishing activities and ecology, we study how eutrophication and climate warming influence plankton biodiversity in Lake Zürich and the consequent effects on fishers’ behavior and fishery yield. Our analysis indicates that changes in the fishery of Lake Zürich were driven by complex dynamic interactions between fishing efforts, environmental conditions

We consider a fishery described by two state variables, namely, the stock of fish and its marine environmental quality, operationalized as an index of habitat extent and quality, which influences the growth rate and the carrying capacity (MEQ). Assuming that myopic fishing agents exploit the fishery, we characterize and contrast the steady‐state values in two scenarios: (a) a scenario where the agents

Conversion of grassland to cropland has been linked to many complex environmental challenges in natural resource systems. South Dakota is a mosaic of grasslands, wetlands, and cropland that has experienced tremendous land use change over the past 10 years and is expected to continue for the next 50 years. The rate of future conversion may vary greatly depending on economic, policy, and social factors

This study aims at the spatial‐temporal evaluation of projected hydrological flow characteristics under varying climate projections driven by RCP 4.5 scenario for 10 selected catchments in Poland using deterministic and stochastic concepts: to assess dependency characteristics of flow variables; to classify flood type regimes using flood duration and magnitude; and to assess and evaluate the changes

As most natural resources, fisheries are affected by random disturbances. The evolution of such resources may be modeled by a succession of deterministic process and random perturbations on biomass and/or growth rate at random times. We analyze the impact of the characteristics of the perturbations on the management of natural resources. We highlight the importance of using a dynamic programming approach

The Soil Conservation Service‐Curve Number (SCS‐CN) method was chosen to calculate the effective precipitation used in hydrological modeling. The assumption of the method is to correlate effective precipitation with the type of land cover, the type of soil and moisture conditions. All these factors include a dimensionless CN parameter. In the analysis, a modification of forest cover was used, taking

In many spatial resource models, it is assumed that an agent is able to harvest the resource over the complete spatial domain. However, agents frequently only have access to a resource at particular locations at which a moving biomass, such as fish or game, may be caught or hunted. Here, we analyze an infinite time‐horizon optimal control problem with boundary harvesting and (systems of) parabolic

The three‐dimensional (3D) terrestrial laser scanning (TLS) system was used to obtain the point cloud data of Betula platyphylla sample trees and the diameter at breast height (DBH), tree height, and biomass were measured for these trees. A 3D point cloud model was constructed to obtain the parameters, such as trunk volume, crown volume, and crown surface area. Then, the TLS‐based parameters were introduced

Green production and green consumption have always been topics of concern. This study explores the coupling relationship between green production and green consumption by setting up a coupling coordination degree model using 2006–2015 panel data for the Yangtze River Delta area. The results highlight that, first, the contribution rate of the tertiary industry to the gross domestic product index is

The copula functions are frequently used by researchers for modeling dependence structure among the correlated attributes in many areas. The copulas are widely used for the analysis of drought frequency, drought characteristics, drought coincidence risk, uncertainty, and drought forecasting. In this research, we have compared two indices of drought assessment, including SPI‐12 and copula‐based joint

Forest product trade plays an important role in the development of the Chinese forest industry. The trading value of forest product has shown a yearly growth rate of 12% during the last five recent years. Stringent environmental regulations in China have a profound impact on raw material supplies and industrial production in the forest sector; however, their impact on the forest product trade is still

Growing global food demands place major strains on water resources, including quality impairments and increased water scarcity. Drawing on the largely separate bodies of literature on externalities and technological innovation, this article develops a dynamic framework to explore the long‐term impacts of alternative policy approaches to the agricultural impacts on water resources. Environmental policies

While the number of models dedicated to predicting the consequences of alternative resource management strategies has increased, instances in which authors look back at past predictions to learn from discrepancies between these and observed developments are scarce. In the past decades, the French Guiana shrimp fishery has experienced shrimp market globalization and decreasing levels of shrimp recruitment

A model is proposed to understand the dynamics in a food chain (one predator‐two prey). Unlike many approaches, we consider mutualism (for defense against predators) between the two groups of prey. We investigate the conditions for coexistence and exclusion. Unlike Elettreby's (2009) results, we show that prey can coexist in the absence of predators (as expected since there is no competition between

This study attempts to model snow wetness and snow density of Himalayan snow cover using a combination of Hyperspectral image processing and Artificial Neural Network (ANN). Initially, a total of 300 spectral signature measurements, synchronized with snow wetness and snow density, were collected in the field. The spectral reflectance of snow was then modeled as a function of snow properties using ANN

The point‐input, point‐output, plantation forest was first studied by Martin Faustmann in the mid‐19th century. The exploitation of a Faustmannian forest involves decisions concerning investments and receipts over time that are qualitatively different from the smooth, convex flows that are usually studied in the economics of accounting. The simple, well understood analysis of the forest has implications

We explore numerically the possibility of controlling the spread of plant diseases characterized by relatively low dispersal (crowd diseases) through the introduction of a spatial barrier with low density of susceptible hosts. We use the diffusion approximation to Kendall's spatially extended version of the Kermack–McKendrick epidemic model and illustrate our findings within the context of a representative

Despite repeated calls for a thorough cleanup of water pollution in the Ganges river, there are only two papers in the social sciences by Batabyal and Beladi (2017, 2019) that have shed theoretical light on this cleanup problem and its connection to the sustainability of tourism in Varanasi. Hence, we extend the above‐mentioned analyses and focus on two specific questions. First, we introduce the notion

We studied transboundary groundwater management problems in the presence of hydraulic fracturing. We found that the presence of risk suggests there should be caution when considering hydraulic fracturing. Our results from the cooperative solution show a decrease in hydraulic fracturing and increase in the steady state survival rate of groundwater. We also provide a Pigouvian type tax that could be

The production behavior of farm households has been a topic of interest for a long time. We explore the optimal production strategies from a household's perspective under the assumption of separability between consumption and production. The data used for this study come from farm households located in five provinces of China. To identify the impacts of various parameters on farmers' production behavior