RESUMEN
To be able to protect biodiversity in coming decades, conservation strategies need to consider what sites will be important for species not just today but also in the future. Different methods have been proposed to identify places that will be important for species in the future. Two of the most frequently used methods, ecological niche modeling and climate resilience, have distinct aims. The former focuses on identifying the suitable environmental conditions for species, thus protecting the "actor," namely, the species, whereas the latter seeks to safeguard the "stage," or the landscape in which species occur. We used the two methods to identify climate refugia for 258 forest vertebrates under short- and long-term climatic changes in a biodiversity hotspot, the Appalachian ecoregion of the United States. We also evaluated the spatial congruence of the two approaches for a possible conservation application, that of protecting 30% of the Appalachian region, in line with recent national and international policy recommendations. We detected weak positive correlations between resilience scores and baseline vertebrate richness, estimated with ecological niche models for historical (baseline) climatic conditions. The correlations were stronger for amphibians and mammals than for birds and reptiles. Under climate change scenarios, the correlations between estimated vertebrate richness and resilience were also weakly positive; a positive correlation was detected only for amphibians. Locations with estimated future gain of suitable climatic conditions for vertebrates showed low correlation with resilience. Overall, our results indicate that climate resilience and ecological niche modeling approaches capture different characteristics of projected distributional changes of Appalachian vertebrates. A climate resilience (the stage) approach could be more effective in safeguarding species with low dispersal abilities, whereas an ecological niche modeling (the actor) approach could be more suitable for species with long-distance dispersal capacity because they may be more broadly impacted by climate and less sensitive to geophysical features captured by a climate resilience approach.
Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales , Animales , Conservación de los Recursos Naturales/métodos , Biodiversidad , Ecosistema , Vertebrados , Anfibios , MamíferosRESUMEN
The role of time in estimating the cost of forest carbon is often ignored in the literature, nor does the literature address the issues of where and when the purchase of forest carbon storage becomes socially beneficial. In our study, we identify the spatial and temporal allocations of forest carbon investments that are socially beneficial based on empirical analysis. We use the Central and Southern Appalachian region in the Eastern United States as a case study over three periods (i.e., 1992-2001, 2001-2006, and 2006-2011) that are roughly in line with moderate, upturn, and downturn market conditions. The areas from which it is socially beneficial to buy carbon storage are mainly in flat terrain and further away from urban boundaries, hence facing lower development pressure and lower urban net returns. These areas also have less urban land and more forestland. The mapping of carbon cost over the three market conditions in our case study also indicates that the socially beneficial carbon area shrinks as the opportunity cost increases when the real-estate market evolves from a moderately growing to a booming market. The socially beneficial carbon area shrinks further as the demand from urban development on forestland collapses when the real-estate market enters a downturn stage.
Asunto(s)
Carbono , Bosques , Región de los Apalaches , Carbono/análisis , Estados UnidosRESUMEN
The environmental benefits and costs of conservation policies often vary over space and through time. Accounting for this spatial and temporal heterogeneity has important implications for the potential cost effectiveness of different payment program designs. In this study, we examine the cost efficiency gain from spatial and temporal targeting in payment designs for forest carbon storage in the Central and Southern Appalachian Mountains in the Eastern United States. We run a forest land change model and a carbon simulation model utilizing a panel data on forest land and its competing uses, economic returns, and spatial characteristics for each 1â¯km2 grid cells in 1992, 2001, 2006 and 2011. A time- and space-specific carbon cost for each individual 1â¯km2 grid cell is calculated that captures the spatial and temporal heterogeneity in carbon cost efficiency. From there, we compare carbon cost efficiency levels of various payment designs that allow for different degrees of spatial and temporal flexibility. We find that 1) spatial targeting improves carbon cost efficiency, and this efficiency gain is larger as payments become more narrowly targeted, 2) this carbon efficiency gain is present in all market conditions, but is largest in a moderately growing market and smallest in a downturn market, 3) accounting for temporal heterogeneity results in even larger carbon efficiency gains, almost double those from spatial targeting. Just as policies that enable spatial targeting (e.g., auctions) increase cost efficiency savings, so too will policy mechanisms that emphasize budget flexibility through time. These could include utilizing loans or flexible conservation financing, or allowing movement across budgeting categories within a given time period.
Asunto(s)
Carbono , Conservación de los Recursos Naturales , Región de los Apalaches , Análisis Costo-Beneficio , Ecosistema , Bosques , Estados UnidosRESUMEN
The objective of this research is to examine how protected area size influences the conservation benefit and acquisition cost of creating a protected area, how the resulting effects influence the predicted rate of return on investment (ROI), and how those relationships change prioritization decision-making for selecting protected areas compared with decisions based only on conservation benefit and decisions based only on acquisition cost. The objective is accomplished in an econometric framework by analyzing the parcel-level acquisition cost and conservation benefit measured by the change in potential fragmentation patterns on the landscape resulting from protection. We focus on areas acquired by The Nature Conservancy in central and southern Appalachia, United States. As an indicator of the change in landscape fragmentation, we use a fragmentation statistic known as effective mesh size. Although the effect of protected parcel size on predicted ROI is inelastic, greater conservation effectiveness is obtained with larger protected parcels than with smaller ones on average. Protected parcel size influences parcels' rankings for protection more (less) when only the predicted change in effective mesh size of protected area (only the predicted acquisition cost per area) is used for prioritizing parcels than when the ranking of parcels is determined by the predicted ROI. These findings imply that, although protected parcel size is important, failure to prioritize using ROI could result in an inappropriate level of emphasis being given to protected parcel size than is warranted.
Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Región de los Apalaches , Costos y Análisis de Costo , Inversiones en Salud , Estados UnidosRESUMEN
Background and objectives: Single-port laparoscopic appendectomy (SLA) in most previous studies has used intracorporeal excision of the appendix and needed a longer operative time than multi-port laparoscopic appendectomy (MLA), although SLA does have the potential benefit of an almost invisible scar within the umbilicus. Some studies have reported that extracorporeal transumbilical single-incision laparoscopic-assisted appendectomy (TULAA) in children took a considerably reduced operative time compared to MLA. We adopted TULAA in adults, adding routine dissection of the peritoneal attachment of the appendix. The aim was to compare the operative outcomes between TULAA and MLA. Materials and Methods: Between March 2013 and January 2016, 770 patients with acute uncomplicated and complicated appendicitis from 15 to 75 years of age were enrolled retrospectively. The operation was performed as early (EA) and interval appendectomy (IA). Results: Operative time was shorter in the TULAA group than in the MLA group, except for IA. No open conversion occurred in the TULAA group, except one case of ileocecal resection for IA. No intra-abdominal fluid collection was found in the TULAA group. Extended resection (especially partial cecectomy) was performed less frequently in the TULAA group than in the MLA group for IA. Mean postoperative hospital stay was shorter in the TULAA group for uncomplicated appendicitis. When the data of the EA group and the IA group were compared, operative time was significantly shorter in the IA group for both MLA and TULAA. The open conversion rate and the complication rate tended to be lower in the IA group. Confined to IA, the TULAA group tended to have shorter mean initial, postoperative, and total hospital stays. Conclusions: TULAA can be a useful surgical alternative to MLA in adults and young adolescents, because it lacks open conversion and provides both a shorter operative time and a shorter postoperative hospital stay. TULAA is feasible for IA in that it showed a lower rate of extended resection and complications.
Asunto(s)
Apendicectomía/métodos , Laparoscopía/métodos , Ombligo/cirugía , Adolescente , Adulto , Apendicectomía/instrumentación , Apendicitis/cirugía , Femenino , Humanos , Laparoscopía/instrumentación , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , República de Corea , Estudios Retrospectivos , Estadísticas no Paramétricas , Resultado del TratamientoRESUMEN
Site-specific estimates of the values of spatial configuration and forest composition are presented. Amenity values of forest patches are found to vary the most by urban and sprawling development patterns of specific areas and forest types. For example, smaller patches of deciduous forest are more highly valued in the urban and sprawling areas of Greensboro, North Carolina, whereas larger patches of deciduous forest are more highly valued in the urban and sprawling areas of Greenville, South Carolina. Within the Greenville and Greensboro areas, visible landscape complexity is highly valued for deciduous and evergreen forest patches, whereas lower visible landscape complexity, i.e., smoothly trimmed forest patch boundaries, is highly valued for mixed forest patches.
Asunto(s)
Monitoreo del Ambiente/métodos , Modelos Teóricos , Árboles , North Carolina , South Carolina , Estados UnidosRESUMEN
Conservation organizations must redouble efforts to protect habitat given continuing biodiversity declines. Prioritization of future areas for protection is hampered by disagreements over what the ecological targets of conservation should be. Here we test the claim that such disagreements will become less important as conservation moves away from prioritizing areas for protection based only on ecological considerations and accounts for varying costs of protection using return-on-investment (ROI) methods. We combine a simulation approach with a case study of forests in the eastern United States, paying particular attention to how covariation between ecological benefits and economic costs influences agreement levels. For many conservation goals, agreement over spatial priorities improves with ROI methods. However, we also show that a reliance on ROI-based prioritization can sometimes exacerbate disagreements over priorities. As such, accounting for costs in conservation planning does not enable society to sidestep careful consideration of the ecological goals of conservation.
Asunto(s)
Conservación de los Recursos Naturales/economía , Costos y Análisis de Costo , Bosques , Objetivos Organizacionales , Biodiversidad , Técnicas de Planificación , Estados UnidosRESUMEN
This study applies a hedonic model to assess the economic benefits of air quality improvement following the 1990 Clean Air Act Amendment at the county level in the lower 48 United States. An instrumental variable approach that combines geographically weighted regression and spatial autoregression methods (GWR-SEM) is adopted to simultaneously account for spatial heterogeneity and spatial autocorrelation. SEM mitigates spatial dependency while GWR addresses spatial heterogeneity by allowing response coefficients to vary across observations. Positive amenity values of improved air quality are found in four major clusters: (1) in East Kentucky and most of Georgia around the Southern Appalachian area; (2) in a few counties in Illinois; (3) on the border of Oklahoma and Kansas, on the border of Kansas and Nebraska, and in east Texas; and (4) in a few counties in Montana. Clusters of significant positive amenity values may exist because of a combination of intense air pollution and consumer awareness of diminishing air quality.