Delineating protected wildlife corridors with multi‐objective programming

Protected wildlife corridors can help counteract habitat fragmentation and link isolated reserve “islands” into connected reserve systems. The need for wildlife corridors will grow as expanding human populations place increasing pressure on remaining undeveloped land. A two‐objective zero–one programming model is formulated for the problem of selecting land for a system of wildlife corridors that must connect a known set of existing reserves or critical habitat areas. This problem is modeled as a network Steiner tree problem, under the objectives of minimizing corridor land costs and minimizing the amount of unsuitable land within the corridor system. Linear programming is used to find exact solutions with little or no branching and bounding, and the multi‐objective weighting method is used to generate non‐inferior alternatives. Two hypothetical examples demonstrate the model and solution procedure. Results can help inform planning and decision making for protected area land acquisition and habitat restoration.     

Integrating Land Market Feedbacks into Conservation Planning—A Mathematical Programming Approach

Nature reserves are often designated ad hoc. Despite increasing conservation efforts, loss of biodiversity is still accelerating. Considering land scarcity and demand for alternative uses, efficiency in conservation strongly correlates with efficiency in land allocation. Systematic conservation planning can effectively prioritize conservation activities. Previous studies minimize opportunity costs for given conservation targets. However, these studies assume constant marginal costs of habitat protection. We extend this cost minimization approach by also considering a dynamic representation of marginal costs. The more land is allocated to nature reserves, the higher are opportunity costs, i.e., costs of forgone agricultural production. This increase in costs results from changes in the prices of agricultural commodities. We employ a deterministic, spatially explicit mathematical optimization model to allocate species habitats by minimizing opportunity costs for setting aside land for conservation purposes. The model is designed as a mixed integer programming problem and solved with GAMS/CPLEX. Our results show the need for integrating land market feedbacks into conservation planning. We find that ignoring land rent adjustments can lead to highly cost-ineffective solutions in reserve selection.     

A Data-Based Conservation Planning Tool for Florida Panthers

Habitat loss and fragmentation are the greatest threats to the endangered Florida panther (Puma concolor coryi). We developed a data-based habitat model and user-friendly interface so that land managers can objectively evaluate Florida panther habitat. We used a geographic information system (GIS) and the Mahalanobis distance statistic (D ²) to develop a model based on broad-scale landscape characteristics associated with panther home ranges. Variables in our model were Euclidean distance to natural land cover, road density, distance to major roads, human density, amount of natural land cover, amount of semi-natural land cover, amount of permanent or semi-permanent flooded area–open water, and a cost–distance variable. We then developed a Florida Panther Habitat Estimator tool, which automates and replicates the GIS processes used to apply the statistical habitat model. The estimator can be used by persons with moderate GIS skills to quantify effects of land-use changes on panther habitat at local and landscape scales. Example applications of the tool are presented.     

Using an Allowance Reserve to Manage Uncertain Costs in a Cap-and-Trade Program for Greenhouse Gases

This paper investigates the design and performance of an allowance reserve in the context of a cap-and-trade program for greenhouse gases. We use a Monte Carlo approach in which the parameters of the marginal abatement cost function, and the supply of offsets, are drawn from specified distributions. Our framework focuses on the potential impact of “medium-run shocks” to abatement cost and offset supply, as opposed to either short-run volatility or permanent shifts in the cost curve. Our model suggests that under reasonable (and even fairly conservative) assumptions about abatement cost and offset supply, an allowance reserve broadly similar to recent proposals for US climate legislation can be effective in containing allowance prices. In our core policy scenario, with a trigger price equal to US $32 in 2015, we estimate that the probability of drawing on the allowance reserve is <25% and the probability of requiring more than 7?GT of reserve tons over 20?years is <5%. We also use the model to explore the trade-off among three features of the reserve that are most relevant to policy makers: the total size of the reserve, the trigger price, and the degree of confidence that the reserve will be large enough to limit allowance prices to the target level. Our essential result is that a lower trigger price, or a higher degree of confidence, requires a larger reserve.     

Exploring Environmental and Economic Trade-offs Associated with Aggregate Recycling from Decommissioned Forest Roads

Forest road decommissioning is a pro-active mechanism for preventing future habitat degradation and for increasing the likelihood of endangered salmonid survival in the western U.S. High implementation costs however preclude many desirable projects from being undertaken, especially on federally owned land. Previous research and real-world applications have demonstrated the cost savings potential of reusing aggregate recovered from forest roads during decommissioning. These cost savings can effectively subsidize decommissioning projects, suggesting an economic benefit associated with improving environmental benefit. We present a mixed integer, multiple objective formulation to identify the efficient trade-off surface between conflicting economic and environmental criteria, where environmental benefit is defined as the hazard weighted length of roads decommissioned. We compare nondominated frontiers identified with and without the opportunity to recycle aggregate. Our results suggest that aggregate recycling promotes a synergistic relationship between cost savings (subsidy) and environmental performance, where subsidies generally increase with increasing environmental performance. Effective subsidy values can reach 31% of total expenditure, at the maximum level of environmental benefit. Transportation managers are therefore able to recover and reuse a nonrenewable resource, while at the same time promoting economic and environmental efficiency.     

Natural and anthropogenic influences on a red-crowned crane habitat in the Yellow River Delta Natural Reserve, 1992–2008

This study aims to assess the relative importance of natural and anthropogenic variables on the change of the red-crowned crane habitat in the Yellow River Nature Reserve, East China using multitempopral remote sensing and geographic information system. Satellite images were used to detect the change in potential crane habitat, from which suitable crane habitat was determined by excluding fragmented habitat. In this study, a principal component analysis (PCA) with seven variables (channel flow, rainfall, temperature, sediment discharge, number of oil wells, total length of roads, and area of settlements) and linear regression analyses of potential and suitable habitat against the retained principal components were applied to explore the influences of natural and anthropogenic factors on the change of the red-crowned crane habitat. The experimental results indicate that suitable habitat decreased by 5,935 ha despite an increase of 1,409 ha in potential habitat from 1992 to 2008. The area of crane habitat changed caused by natural drivers such as progressive succession, retrogressive succession, and physical fragmentation is almost the same as that caused by anthropogenic forces such as land use change and behavioral fragmentation. The PCA and regression analyses revealed that natural factors (e.g., channel flow, rainfall, temperature, and sediment discharge) play an important role in the crane potential habitat change and human disturbances (e.g., oil wells, roads, and settlements) jointly explain 51.8 % of the variations in suitable habitat area, higher than 48.2 % contributed by natural factors. Thus, it is vital to reduce anthropogenic influences within the reserve in order to reverse the decline in the suitable crane habitat.     

Applying parcel-specific land-use data for improved monitoring of semi-natural grassland in Denmark

A major obstacle to the conservation and management of semi-natural grassland (SNG) is the general lack of consistent and precise maps showing the extent and quality of this habitat type. SNG is related to, and influenced by, agricultural land use. Both intensive land use as well as a lack of extensive land use can reduce the extent and quality of SNG. For Denmark, this paper demonstrates how parcel-specific land-use data can be applied to detect localities with spatial convergences and conflicts between SNG and agricultural land use. Based on their respective influence on SNG, land use is aggregated into five major classes and spatially overlaid with existing nationally registered SNG. Results show that almost 11 % of all SNG is mapped either on cropped land or on rotational grassland, indicating a conflict between mapped SNG and land use. Thirty percent of SNG is mapped outside any agricultural land use, pointing to a lack of management. Fifty nine percent of SNG is mapped either on land receiving payments for grazing/mowing or on other land under extensive management, indicating a convergence between SNG and land use. Finally, 30 % of land receiving payments for grazing/mowing and 62 % of other land under extensive management does not contain any semi-natural habitat. Potential, as yet unmapped, SNG might exist in these localities. Based on these results it is argued that the application of parcel-specific land-use data could significantly improve monitoring of SNG.     

Reserve Design to Maximize Species Persistence

We develop a reserve design strategy to maximize the probability of species persistence predicted by a stochastic, individual-based, metapopulation model. Because the population model does not fit exact optimization procedures, our strategy involves deriving promising solutions from theory, obtaining promising solutions from a simulation optimization heuristic, and determining the best of the promising solutions using a multiple-comparison statistical test. We use the strategy to address a problem of allocating limited resources to new and existing reserves. The best reserve design depends on emigration, dispersal mortality, and probabilities of movement between reserves. When movement probabilities are symmetric, the best design is to expand a subset of reserves to equal size to exhaust the habitat budget. When movement probabilities are not symmetric, the best design does not expand reserves to equal size and is strongly affected by movement probabilities and emigration rates. We use commercial simulation software to obtain our results.     

Spatio-temporal pattern and rationality of land reclamation and cropland abandonment in mid-eastern Inner Mongolia of China in 1990�C2005

The Mid-eastern Inner Mongolia of China, a typical agro-pastoral transitional zone, has undergone rapid agricultural land use changes including land reclamation and cropland abandonment in past decades due to growing population and food demand, climatic variability, and land use policy such as the "Grain for Green" Project (GFG Project). It is significant to the regional ecology and sustainability to examine the pattern and its rationality of land use change. The processes of land reclamation and cropland abandonment were accessed by using land use change dataset for four periods of 1990, 1995, 2000, and 2005, derived from the interpretation of Landsat TM images. And then the rationality of land reclamation and cropland abandonment was analyzed based on the habitat suitability for cultivation. The results indicated that: (1) land reclamation was the dominant form of agricultural land use change from 1990 to 2005, the total cropland area increased from 64,954.64 km(2) in 1990 to 76,258.51 km(2) in 2005; However, the speed of land reclamation decreased while cropland abandonment increased around 2000. The Land Reclamation Degree decreased from 1995-2000 to 2000-2005, meanwhile, Cropland Abandonment Degree increased. (2) As for the habitat suitability levels, moderately and marginally suitable levels had largest areas where cropland was widespread. Pattern of agricultural land use trended to become more rational due to the decrease of land reclamation area in low suitable levels and the increase of cropland abandonment in unsuitable area after 2000. (3) The habitat suitability-based rationality analysis of agricultural land use implicated that the GFG Project should take cultivation habitat suitability assessment into account.     

Marine Reserve Design with Ocean Currents and Multiple Objectives

There is a growing tendency to consider marine reserves as a management and conservation tool. We investigate a spatial bio-economic model to determine fishery profits under conservation efforts. Rather than imposing a marine reserve on our model, we ask, “When and where should a marine reserve be implemented ?” For one-dimensional habitat, we determine conditions under which marine reserves emerge as a part of the optimal policy. Depending upon the size of the habitat, the optimal strategy is either to avoid fishing or to fish at maximum rate. The effect of ocean currents is analyzed through numerical simulations. We find that in the presence of strong currents, a marine reserve may become ineffective. If the currents are at low rate, a marine reserve could emerge as a variable management tool.     

Assessing the wildlife habitat value of New England salt marshes: II. Model testing and validation

We tested a previously described model to assess the wildlife habitat value of New England salt marshes by comparing modeled habitat values and scores with bird abundance and species richness at sixteen salt marshes in Narragansett Bay, Rhode Island USA. As a group, wildlife habitat value assessment scores for the marshes ranged from 307-509, or 31-67% of the maximum attainable score. We recorded 6 species of wading birds (Ardeidae; herons, egrets, and bitterns) at the sites during biweekly survey. Species richness (r (2)=0.24, F=4.53, p=0.05) and abundance (r (2)=0.26, F=5.00, p=0.04) of wading birds significantly increased with increasing assessment score. We optimized our assessment model for wading birds by using Akaike information criteria (AIC) to compare a series of models comprised of specific components and categories of our model that best reflect their habitat use. The model incorporating pre-classification, wading bird habitat categories, and natural land surrounding the sites was substantially supported by AIC analysis as the best model. The abundance of wading birds significantly increased with increasing assessment scores generated with the optimized model (r (2)=0.48, F=12.5, p=0.003), demonstrating that optimizing models can be helpful in improving the accuracy of the assessment for a given species or species assemblage. In addition to validating the assessment model, our results show that in spite of their urban setting our study marshes provide substantial wildlife habitat value. This suggests that even small wetlands in highly urbanized coastal settings can provide important wildlife habitat value if key habitat attributes (e.g., natural buffers, habitat heterogeneity) are present.     

山东省省级自然保护区人类活动遥感监测与评价

基于2018年高分系列遥感影像数据,提取山东省省级自然保护区人类土地利用活动信息,探讨人类活动对山东省省级自然保护区的影响。结果表明,自然保护区人类活动总面积占保护区总面积的22.2%,人类活动影响指数介于0~0.01368。不同类型的自然保护区人类活动面积不同,主要影响因子差异明显,森林生态类保护区以农业用地为主,内陆湿地类保护区以养殖场为主。内陆湿地类保护区是受到人类干扰程度最为严重的保护区类型,野生动物类保护区受到人类影响最小。     

Effects of the Conservation Reserve Program on northern bobwhite and grassland birds

The Conservation Reserve Program (CRP) has converted just over 36 million acres of cropland into potential wildlife habitat, primarily grassland. Thus, the CRP should benefit grassland songbirds, a group of species that is declining across the United States and is of conservation concern. Additionally, the CRP is an important part of multi-agency, regional efforts to restore northern bobwhite populations. However, comprehensive assessments of the wildlife benefits of CRP at regional scales are lacking. We used Breeding Bird Survey and National Resources Inventory data to assess the potential for the CRP to benefit northern bobwhite and other grassland birds with overlapping ranges and similar habitat associations. We built regression models for 15 species in seven different ecological regions. Forty-nine of 108 total models contained significant CRP effects (P < 0.05), and 48 of the 49 contained positive effects. Responses to CRP varied across ecological regions. Only eastern meadowlark was positively-related to CRP in all the ecological regions, and western meadowlark was the only species never related to CRP. CRP was a strong predictor of bird abundance compared to other land cover types. The potential for CRP habitat as a regional conservation tool to benefit declining grassland bird populations should continue to be assessed at a variety of spatial scales. We caution that bird-CRP relations varied from region to region and among species. Because the NRI provides relatively coarse resolution information on CRP, more detailed information about CRP habitats (spatial arrangement, age of the habitat (time since planting), specific conservation practices used) should be included in future assessments to fully understand where and to what extent CRP can benefit grassland birds.     

A Spatial Analysis of the Economic and Ecological Efficacy of Land Retirement

This paper uses a cellular automata simulation model of a hypothetical landscape to investigate the role of location as it relates to the efficacy of land retirement in achieving two environmental goals: hydrological improvement and habitat improvement. Statistical analysis of simulation results is used to show how absolute and relative location relate to achievement of these objectives. Linear and nonlinear compromise programming frameworks then combine these two environmental objectives and a cost minimization objective into a measure that allows decision-makers to rank the desirability of different retirement strategies. These frameworks are explored to determine what each implies about the tradeoffs that must be made among objectives and among the spatial land parcel characteristics that contribute to those objectives.     

A multi-scale qualitative approach to assess the impact of urbanization on natural habitats and their connectivity

Habitat loss and fragmentation are often concurrent to land conversion and urbanization. Simple application of GIS-based landscape pattern indicators may be not sufficient to support meaningful biodiversity impact assessment. A review of the literature reveals that habitat definition and habitat fragmentation are frequently inadequately considered in environmental assessment, notwithstanding the increasing number of tools and approaches reported in the landscape ecology literature.This paper presents an approach for assessing impacts on habitats on a local scale, where availability of species data is often limited, developed for an alpine valley in northern Italy. The perspective of the methodology is multiple scale and species-oriented, and provides both qualitative and quantitative definitions of impact significance. A qualitative decision model is used to assess ecological values in order to support land-use decisions at the local level. Building on recent studies in the same region, the methodology integrates various approaches, such as landscape graphs, object-oriented rule-based habitat assessment and expert knowledge.The results provide insights into future habitat loss and fragmentation caused by land-use changes, and aim at supporting decision-making in planning and suggesting possible ecological compensation.     

Applying mathematical programming to reserve selection

During the last 10–15 years heuristic methods have been developed for problems in optimal reserve selection. Unfortunately, there is no guarantee that heuristics will find optimal solutions. In recognizing this limitation, analysts have formulated reserve selection problems as set covering problems, for which matrix reduction and integer (0/1) programming can be used to find optimal solutions. In this paper we restate the set covering formulation and review solution techniques. A new 0/1 programming model, which is a generalization of the set covering model, is then presented and applied to a hypothetical reserve selection problem. Objectives of minimizing the number of sites selected and maximizing the number of species represented are addressed. Solutions which characterize the tradeoffs between these objectives provide a rich set of information for planners and decision makers. Applications of mathematical programming to related problems in land use planning and forestry are also discussed.     

丹江湿地国家级自然保护区及其内外区域2000—2015年土地覆被变化分析

为研究2000—2015年丹江湿地国家级自然保护区及其内外生态状况变化和保护成效,基于高分1号数据生产的2m高分辨率遥感影像数据对丹江湿地国家级自然保护区2015年人类活动状况进行分析,基于30 m分辨率的4期TM遥感影像生产的土地覆被数据和基于Modis遥感影像生产的植被覆盖度数据,对淅川县、丹江湿地国家级自然保护区及其核心区的土地覆被状况、土地覆被转类指数及其土地覆被转类途径的主导程度和3个相关区域范围内的生态系统质量以及不同区域土地覆被变化的主要变化原因进行分析。结果表明,保护区核心区的格局和质量在该区域处于最优,且土地覆被变化状况也以核心区转类指数最高;丹江湿地国家级自然保护区内的主要人类活动影响为耕地,其次包括居民点、采石场、养殖场; 15年间,保护区内外土地覆被均呈现转好趋势,但是保护区内变化优于保护区外,保护区核心区优于整个保护区,且转好的主导因素均是耕地变为湿地; 15年间植被覆盖度变化较小。     

金山三岛陆域生态系统健康状况分析评价

在对上海市金山三岛自然保护区陆域生态系统调查研究的基础上,采用层次分析法-综合指数评价模型对其进行生态健康状况评价分析。结果表明,该陆域生态系统综合健康指数(CEI)为0.648,保护区的生态质量一般,生态系统稳定性差,自我恢复能力不强。建议采取一定的人为干预措施来保护金山三岛陆域生态系统,使其朝更优的方向发展。     

The areal extent of brown shrimp habitat suitability in Mobile Bay, Alabama, USA: targeting vegetated habitat restoration

The availability of wetlands and shallow water habitats significantly influences Gulf of Mexico (GOM) penaeid shrimp fishery productivity. However, the GOM region has the highest rate of wetland loss in the USA. Protection and management of these vital GOM habitats are critical to sustainable shrimp fisheries. Brown shrimp (Farfantepenaeus aztecus) are a major component of GOM fisheries. We present an approach for estimating the areal extent of suitable habitat for post-larval and juvenile brown shrimp in Mobile Bay, Alabama, using an existing habitat suitability index model for the northern GOM calculated from probabilistic survey of water quality and sediment data, land cover data, and submerged aquatic vegetation coverages. This estuarine scale approach is intended to support targeted protection and restoration of these habitats. These analyses indicate that approximately 60% of the area of Mobile Bay is categorized as suitable to near optimal for post-larval and juvenile shrimp and 38% of the area is marginally to minimally suitable. We identify potential units within Mobile Bay for targeted restoration to improve habitat suitability.     

Models for preserving species diversity with backup coverage

The problem of selecting land for preservation of species has been a rich and active area of research over the past two decades. Typically, reserve selection models have tried to maximize species diversity by preserving areas that contain the greatest number of species. However, several studies have shown that seldom do these species-rich areas contain the rarest species most in need of protection. Most reserve selection models seek to maximize diversity by choosing parcels so that all species are covered by or represented in at least one parcel. This approach would usually be expected to result in coverage by a single parcel for the rarest species, especially for those that do not coincide with more abundant species. It is precisely these rare species, however, that would be lost or whose survivability would be most challenged, if the single parcels in which they are represented became unavailable due to some unforeseen event. In this paper, we introduce to reserve selection models the concept of secondary, or backup, coverage of species. Briefly stated, a species is said to have backup representation in the system of reserves if it is covered by, or represented in, two or more parcels. Having backup coverage guarantees that every species is still covered in the event that a natural or man-made catastrophe makes a given parcel uninhabitable. The results show that backup coverage can be obtained at little additional cost (as expressed by the number of parcels selected). Bi-objective formulations that trade-off primary with backup coverage show that backup coverage can be guaranteed for larger numbers of species with little reduction in primary coverage.