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

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

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

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 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

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

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

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

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

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

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

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 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

The susceptible-infected-recovered (SIR) model has greatly evidenced epidemiology despite its apparent simplicity. Most applications of the SIR framework use a form of nonlinear incidence to describe the number of new cases per instant. We adapt theorems to analyze the stability of SIR models with a generalized nonlinear incidence structure. These theorems are then applied to the case of standard incidence

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

The dominant differential equation paradigm for modeling the population dynamics of species interacting in the framework of a food web retains at its core the basic prey-predator and competition models formulation by Alfred J. Lotka (1880-1945) and Vito Volterra (1860-1940) nearly nine decades ago. This paradigm lacks a trophic-level-independent formulation of population growth leading to ambiguities

Zoonoses are a worldwide public health concern, accounting for approximately 75% of human infectious diseases. In addition, zoonoses adversely affect agricultural production and wildlife. We review some mathematical models developed for the study of viral zoonoses in wildlife and identify areas where further modeling efforts are needed.

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