Regional-scale Effects Research Articles

Comparative analysis of manure treatment scenarios on climate change and eutrophication in the Baltic Sea

This study conducted a life cycle assessment (LCA) of manure management, identifying transportation as a major contributor to global warming and freshwater eutrophication impacts. Transporting substrates to the biogas plant was the main hotspot, highlighting a critical area for improvement. The findings emphasize the importance of method selection in geographically dependent assessments, especially in the Baltic Sea region. Characterization factors specific to Sweden revealed higher environmental impact values than those produced by the ReCiPe method, underscoring the need for regional differentiation in LCA. By optimizing manure management practices and enhancing nutrient distribution, impacts on both climate change and eutrophication can be significantly reduced, thereby lowering nutrient flow to the Baltic Sea. Combining these optimizations with transportation impact reductions further amplifies these environmental benefits, demonstrating that geographically tailored approaches in LCA offer essential insights for managing regional-scale effects.

Woody encroachment induced earlier and extended growing season in boreal wetland ecosystems.

Woody plant encroachment (WPE), a widespread ecological phenomenon globally, has significant impacts on ecosystem structure and functions. However, little is known about how WPE affects phenology in wetland ecosystems of middle and high latitudes. Here, we investigated the regional-scale effects of WPE on the start (SOS), peak (POS), end (EOS), and length (GSL) of the growing season in boreal wetland ecosystems, and their underlying mechanisms, using remote sensing dataset during 2001-2016. Our results showed that WPE advanced the annual SOS and POS, while delaying EOS and extending GSL in boreal wetlands with these impacts increasing over time. When boreal wetland ecosystems were fully encroached by woody plants, the SOS and POS were advanced by 12.17 and 5.65 days, respectively, the EOS was postponed by 2.74 days, and the GSL was extended by 15.21 days. We also found that the impacts of WPE on wetland SOS were predominantly attributed to the increased degree of WPE (α), while climatic factors played a more significant role in controlling the POS and EOS responses to WPE. Climate change not only directly influenced phenological responses of wetlands to WPE but also exerted indirect effects by regulating soil moisture and α. Winter precipitation and spring temperature primarily determined the effects of WPE on SOS, while its impacts on POS were mainly controlled by winter precipitation, summer temperature, and precipitation, and the effects on EOS were mainly determined by winter precipitation, summer temperature, and autumn temperature. Our findings offer new insights into the understanding of the interaction between WPE and wetland ecosystems, emphasizing the significance of considering WPE effects to ensure accurate assessments of phenology changes.

Local and regional-scale effects of hedgerows on grassland- and forest-associated bird populations within agroecosystems.

Linear woody features (LWFs), like hedgerows along field edges, provide wildlife habitat and support biodiversity in agroecosystems. Assessments of LWFs usually focus on community-level indices, such as species richness. However, effective conservation actions need to balance the contrasting habitat preferences of different wildlife species, necessitating a focus on population-level effects in working landscapes. We assessed associations between LWFs and abundance for 45 bird species within an intensive agroecosystem in eastern Ontario, Canada. We used distance- and removal-sampling methods across 4 years (2016-2019) to estimate local bird abundance in habitats representing a range of LWF densities. We also predicted abundance across a subset of the study region with and without LWFs to understand their contribution to regional population density. Associations between local bird abundance and LWFs were variable among species, but overall community effects were clearly positive, particularly for forest and shrubland species. At the site level, 20/45 species (44%) had higher densities associated with greater LWF presence on average, compared to 5/45 (11%) with negative associations. At the regional scale, LWFs had predicted benefits on total abundance for 31 species (69%), contributing to an estimated 20% increase on average. Positive effects were most pronounced in areas with greater agricultural land use (primarily field crops), suggesting LWFs may provide crucial habitat in heavily modified landscapes but have little to no additional benefit for the avian community in areas with greater existing heterogeneity and habitat retention. Species that responded negatively tended to be at risk with strong habitat preferences for intact forests or large, open grasslands and, thus, greater sensitivity to potential edge effects. With rapidly declining songbird populations and a global need for food security, conservation strategies that amplify biodiversity and enhance agricultural productivity through ecosystem services such as pest control, pollination, and water regulation are vital. We demonstrate the benefits of habitat heterogeneity in agroecosystems on songbird densities and highlight the need to integrate local and landscape-level assessments in conservation planning. An effective, balanced strategy includes concentrating LWFs in areas of extensive arable crops, with habitat retention patches where possible, while maintaining heterogeneity through mixtures of natural habitats and pastoral farming in less intensive regions.

Assembly rules of coral reef fish communities along the depth gradient

Coral reefs are home to some of the most studied ecological assemblages on the planet. However, differences in large-scale assembly rules have never been studied using empirical quantitative data stratified along the depth gradient of reefs. Consequently, little is known about the small- and regional-scale effects of depth on coral reef assemblages. Using a large dataset of underwater surveys, we observed that the influence of classic biogeographic drivers on the species richness of coral reef fishes changes significantly with depth, shaping distinct assemblages governed by different rules in mesophotic coral ecosystems. We show that a general pattern of decreased taxonomic and functional richness of reef fish assemblages with depth results from convergent filtering of species composition and trophic strategies on deeper reefs across ocean basins and that at smaller scales deep-reef communities are less influenced by regional factors than shallower reefs.

Understanding the effects of digital elevation model resolution and building treatment for urban flood modelling

Study regionA mountain city in the coastal region of Southeast China. Study focusThis study elucidated the effect of digital elevation model (DEM) resolution on flood simulation errors and inundation depth distributions through building treatment methods and river channel definition. The optimal DEM resolution was evaluated to determine whether satisfactory inundation simulation could be achieved for urban flash flood simulation (UFFS) and fluvial overbank flood simulation (FOFS).New hydrological insights for the region: UFFS and FOFS presented opposite effects regarding inundation extent and the spatial distribution of inundation depth with coarsening DEM resolution. In UFFS, the inundation extent and inundation depth in low-lying areas of the flood propagation pathway were underestimated. This effect was attributed to the change of local flood pathway caused by different treatment of buildings at coarser DEM resolution. The simulation error was magnified considerably when the DEM resolution was greater than the building width and gaps. In FOFS, owing to the changed channel geometry at coarser resolution, the inundation extent and inundation depth were overestimated. Using a DEM resolution and computational cell size that are lower than the river width is recommended. This study illustrated that a regional-scale effect, dependent on regional flood propagation behaviour and the impact of land use and topography on the flood propagation pathway, could be observed by coarsening the DEM resolution of inundation simulations.

“Beyond Weather Regimes”: Descriptors Monitoring Atmospheric Centers of Action. A case study for Aotearoa New Zealand

AbstractThis paper introduces a set of descriptors applied to weather regimes, that allow for a detailed monitoring of the location and intensity of their atmospheric centers of action (e.g. troughs and ridges) and the gradients between them, when applicable. Descriptors are designed to document the effect of climate variability and change in modulating the character of daily weather regimes, rather than merely their occurrence statistics.As a case study, the methodology is applied to Aotearoa New Zealand (ANZ), using ERA5 ensemble reanalysis data for the period 1979-2019. Here, we analyze teleconnections between the regimes and their descriptors, and large-scale climate variability. Results show a significant modulation of centers of action by the phase of the Southern Annular Mode, with a strong relationship identified with the latitude of atmospheric ridges. Significant associations with El Niño Southern Oscillation are also identified. Modes of large-scale variability have a stronger influence on the regimes’ intrinsic features than their occurrence. This demonstrates the usefulness of such descriptors, which help understand the relationship between mid-latitude transient perturbations and large-scale modes of climate variability.In future research, this methodological framework will be applied to analyze (i) low-frequency changes in weather regimes under climate change, in line with the southward shift of storm tracks, and (ii) regional-scale effects on the climate of ANZ, resulting from interaction with its topography.

Do metal mines and their runoff affect plumage color? Streak-backed Orioles in Mexico show unexpected patterns

AbstractMetal mining causes serious ecological disturbance, due partly to heavy metal (HM) pollution that can accumulate at mining sites themselves and be dispersed downstream as runoff. Plumage coloration is important in birds’ social and ecological interactions and sensitive to environmental stressors, and several local-scale studies have found decreased carotenoid-based plumage and/or increased melanin-based plumage in wild birds exposed to HM pollution. We investigated regional-scale effects of proximity to mines and their downstream rivers as a proxy of exposure to HM-contaminated mining waste on plumage coloration in Streak-backed Orioles (Icterus pustulatus) in south-central Mexico. We measured the plumage color of museum skins using reflectance spectrometry and digital photography, then used geographic information systems to estimate each specimen’s distance from the nearest mining concession and river and determine whether that river’s watershed contained mines. Proximity to mines and their downstream rivers was related to ventral (but not dorsal) carotenoid-based coloration; birds collected farther from mines had more vivid yellow-orange breast plumage, and belly plumage was more vivid and redder with increasing distance from rivers with upstream mines. Breast background reflectance unexpectedly decreased with mine distance and was higher among birds whose nearest river had mines upstream. The area (but not reflectance) of melanin-based plumage was also related to mines. The area of dark back streaks decreased with mine distance, while the bib patch was smaller among birds presumably more exposed to mining waste. While some of these results are consistent with predicted effects of HM pollution on plumage, most were not straightforward, and effects differed among plumage patches and variables. Further investigation is needed to understand the direct (e.g., toxicity, oxidative stress) and/or indirect (e.g., decreased availability of carotenoid-rich food) mechanisms responsible and their individual-, population-, and community-level implications.

Combined effects of ozone and drought stress on the emission of biogenic volatile organic compounds from <i>Quercus robur</i> L.

Abstract. Drought events are expected to become more frequent with climate change. To predict the effect of plant emissions on air quality and potential feedback effects on climate, the study of biogenic volatile organic compound emissions under stress is of great importance. Trees can often be subject to a combination of abiotic stresses, for example due to drought or ozone. Even though there is a large body of knowledge on individual stress factors, the effects of combined stressors are not much explored. This study aimed to investigate changes of biogenic volatile organic compound emissions and physiological parameters in Quercus robur L. during moderate to severe drought in combination with ozone stress. Results show that isoprene emissions decreased while monoterpene and sesquiterpene emissions increased during the progression of drought. We exposed plants with daily ozone concentrations of 100 ppb for 1 h for 7 d, which resulted in faster stomatal closure (e.g., a mean value of −31.3 % at an average stem water potential of −1 MPa), partially mitigating drought stress effects. Evidence of this was found in enhanced green leaf volatiles in trees without ozone fumigation, indicating cellular damage. In addition we observed an enhancement in (C8H8O3)H+ emissions likely corresponding to methyl-salicylate in trees with ozone treatment. Individual plant stress factors are not necessarily additive, and atmospheric models should implement stress feedback loops to study regional-scale effects.

Effects of landscape heterogeneity on population genetic structure and demography of Amazonian phyllostomid bats

Anthropogenic landscape changes resulting in habitat degradation, loss and fragmentation might decrease connectivity and effective sizes of wild populations, threatening local biodiversity. Assumed large distributions of both species and habitats have probably discouraged studies correlating altered landscapes’ structure and composition to patterns of genetic diversity in the Neotropics. Yet, considering the increasingly high rates of deforestation and habitat conversion in Amazonia, investigating local and regional-scale effects of habitat conversion on Amazonian mammals is of paramount importance. Here, we use widespread, non-threatened, phyllostomid bats to understand how current forest dynamics are influencing genetic diversity patterns and functional connectivity of eastern Amazonian volant mammals. Four frugivorous species, Carollia perspicillata, Rhinophylla pumilio, Dermanura gnoma and Artibeus obscurus, were sampled across a heterogeneously fragmented region. Twelve more or less isolated rainforest remnants surrounded by urban areas, pastures, crops, secondary forests and other land uses comprise the studied landscapes, and are compared using a landscape genetics approach applied to mitochondrial DNA loci. Here, we report species-specific consequences of habitat fragmentation. Although the overall levels of genetic diversity were high, our data show that (i) population structure is heterogeneous across the altered landscapes; (ii) landscapes with higher habitat availability harbour populations with higher genetic diversity; and (iii) the populations assessed might be demographically declining.

Examining Land Use Changes to Evaluate the Effects of Land Management in a Complex, Dynamic Landscape

Anthropogenic alterations to landscapes have increased as the human population continues to rise, leading to detrimental changes in natural habitats. Ecological restoration assists in recovery by altering habitats to improve conditions and foster biodiversity. We examined land cover changes over time within a complex, dynamic region in the Midwest to assess the long-term effects of conservation. We used Landsat 8 bands for a 15-class land cover map of Oak Openings Region using supervised classification. We validated our map and achieved an overall accuracy of 71.2% from correctly classified points out of total visited points. Change over 10 years, from 2006 to 2016, was explored by comparing class statistics from FRAGSTATS between our map and original land cover map. We found that natural land, i.e., forest and early successional, covered 33%, with 10% permanently protected, while human-modified land, i.e., agricultural and developed, covered 67% of the region. Over 10 years, natural classes increased, and cultural classes decreased by 5.8%. There were decreases for the three forest communities and increases for the two early successional communities. These changes are likely the result of natural recovery and disturbance, and conservation efforts by the Green Ribbon Initiative. Changes in habitat also came with distribution changes, e.g., increased fragmentation for some classes, which was readily visible. Our useful method measured functionality by emphasizing changes in composition and configuration. Our approach provides a tool for assessing cumulative regional-scale effects from site-level management and conservation. This large-scale view for conservation is needed to effectively mitigate future changes.

8. The Effect of Bythotrephes Longimanus on the Size Structure of Zooplankton Communities in the Muskoka Region, Ontario

Invasive species are considered the greatest threat to aquatic ecosystem biodiversity. Bythotrephes longimanus, an exotic zooplankton species introduced to North America in the 1980s, is threatening the structure of indigenous aquatic ecosystems as it continues to invade inland Ontario lakes. As a predacious zooplankton species, B. longimanus has been shown to decrease zooplankton abundance, species richness and shift zooplankton community size structure in invaded lakes. However, much of the previous research concerning the predatory effects of B. longimanus has been on surveys of a small number of lakes or has been in controlled mesocosm or lab-based experiments. This study examines the effects of B. longimanus on the zooplankton community using size-structure characterizations (grouping individuals from the community based on size) as community measures for 311 lakes in the Muskoka Region, a highly invaded watershed in Southern Ontario. More specifically, the study explores the size-spectra of invaded versus uninvaded lakes, with reference to an array of environmental lake characteristics (water chemistry, lake morphometry,etc.), and the relevance of B. longimanus activity on the regional scale. By using such a large-scale survey we will be able to appreciate regional-scale effects, as well as encompass the multiple and more indirect trophic interactions that B. longimanus is likely having with the entire aquatic community. (Funding: NSERC & CAISN.)

Regional-scale effects override the influence of fine-scale landscape heterogeneity on rice arthropod communities

Abstract Irrigated rice croplands are among the most biologically diverse agroecosystems globally; however, intensification and simplification of farmed areas into homogeneous monocultures can lead to biodiversity loss and a reduction of associated ecosystem services such as natural pest regulation. Understanding how landscape heterogeneity affects the diversity of arthropod communities is therefore crucial for the sustainable management of rice agroecosystems. Here, we examine the influence of fine-scale landscape heterogeneity and regional-scale effects on the arthropod communities of three rice-production regions in the Philippines. Our analysis of 213 arthropod morphospecies (37,339 individuals) collected using two sampling methods at 28 field sites indicated that the rice agroecosystems in each study region had unique arthropod assemblages, likely reflecting region-specific environmental and land-use conditions. For all sites together, we found no effect of fine-scale landscape context (classified as rather high or low heterogeneity sites) on assemblage structure (arthropod abundance, species richness or diversity). When assemblages were analyzed separately, significant effects of fine-scale landscape context were only detected in one region and for two functional groups (predators and detritivores). Elevation gradient, used as a proxy for regional-scale effects in the study regions, explained more than 60% of variance in assemblage structure. Total arthropod abundance and rarefied species richness were negatively related to elevation, suggesting that regional-scale effects rather than fine-scale landscape heterogeneity explained the composition of rice-arthropod communities in landscapes. To further disentangle the complex effects of broad-scale environmental drivers versus fine-scale landscape complexity on arthropod communities and biocontrol services, future research in rice agroecosystems should focus on a more detailed quantification of landscape heterogeneity and examine its effect at multiple spatial scales.

Extended late Holocene relative sea-level histories for North Carolina, USA

We produced ∼3000-year long relative sea-level (RSL) histories for two sites in North Carolina (USA) using foraminifera preserved in new and existing cores of dated salt-marsh sediment. At Cedar Island, RSL rose by ∼2.4 m during the past ∼3000 years compared to ∼3.3 m at Roanoke Island. This spatial difference arises primarily from differential GIA that caused late Holocene RSL rise to be 0.1–0.2 mm/yr faster at Roanoke Island than at Cedar Island. However, a non-linear difference in RSL between the two study regions (particularly from ∼0 CE to ∼1250 CE) indicates that additional local- to regional-scale processes drove centennial-scale RSL change in North Carolina. Therefore, the Cedar Island and Roanoke Island records should be considered as independent of one another. Between-site differences on sub-millennial timescales cannot be adequately explained by non-stationary tides, sediment compaction, or local sediment dynamics. We propose that a period of accelerating RSL rise from ∼600 CE to 1100 CE that is present at Roanoke Island (and other sites north of Cape Hatteras at least as far as Connecticut), but absent at Cedar Island (and other sites south of Cape Hatteras at least as far as northeastern Florida) is a local-to regional-scale effect of dynamic ocean and/or atmospheric circulation.

Effects of Roughness Length Parameterizations on Regional-Scale Land Surface Modeling of Alpine Grasslands in the Yangtze River Basin

AbstractCurrent land surface models (LSMs) tend to largely underestimate the daytime land surface temperature for high-altitude regions. This is partly because of underestimation of heat transfer resistance, which may be resolved through adequate parameterization of roughness lengths for momentum and heat transfer. In this paper, the regional-scale effects of the roughness length parameterizations for alpine grasslands are addressed and the performance of the Noah LSM using the updated roughness lengths compared to the original ones is assessed. The simulations were verified with various satellite products and validated with ground-based observations. More specifically, four experimental setups were designed using two roughness length schemes with two different parameterizations of (original and updated). These experiments were conducted in the source region of the Yangtze River during the period 2005–10 using the Noah LSM. The results show that the updated parameterizations of roughness lengths reduce the mean biases of the simulated daytime in spring, autumn, and winter by up to 2.7 K, whereas larger warm biases are produced in summer. Moreover, model efficiency coefficients (Nash–Sutcliffe) of the monthly runoff results are improved by up to 26.3% when using the updated roughness parameterizations. In addition, the spatial effects of the roughness length parameterizations on the simulations are discussed. This study stresses the importance of proper parameterizations of and for LSMs and highlights the need for regional adaptation of the and values.

C-TOOL: A simple model for simulating whole-profile carbon storage in temperate agricultural soils

Soil organic carbon (SOC) is a significant component of the global carbon (C) cycle. Changes in SOC storage affect atmospheric CO2 concentrations on decadal to centennial timescales. The C-TOOL model was developed to simulate farm- and regional-scale effects of management on medium- to long-term SOC storage in the profile of well-drained agricultural mineral soils. C-TOOL uses three SOC pools for both the topsoil (0–25cm) and the subsoil (25–100cm), and applies temperature-dependent first order kinetics to regulate C turnover. C-TOOL also enables the simulation of 14C turnover. The simple model structure facilitates calibration and requires few inputs (mean monthly air temperature, soil clay content, soil C/N ratio and C in organic inputs). The model was parameterised using data from 19 treatments drawn from seven long-term field experiments in the United Kingdom, Sweden and Denmark. It was found that the initial SOC content had to be optimised for each experiment, but also that one set of values for other model parameters could be applied at all sites. With this set of parameters, C-TOOL can be applied more widely to evaluate effects of management options on SOC storage in temperate agricultural soils. C-TOOL simulates observed losses of SOC in soils under intensive agricultural use and the gain in SOC derived from large inputs of animal manure and inclusion of perennial grassland. The model simulates changes in SOC for the entire profile, but lack of data on subsoil SOC storage hampers a proper model evaluation. Experimental verification of management effects on subsoil C storage, subsoil C inputs from roots, and vertical transport of C in the soil profile remains prioritised research areas.

Land-use and land-cover effects on regional biodiversity distribution in a subtropical dry forest: a hierarchical integrative multi-taxa study

Latin American subtropical dry ecosystems have experienced significant human impact for more than a century, mainly in the form of extensive livestock grazing, forest products extraction, and agriculture expansion. We assessed the regional-scale effect of land use and land cover (LULC) on patterns of richness distribution of trees, birds, amphibians, and mammals in the Northern Argentine Dry Chaco (NADC) over c. 19 million hectares. Using species distribution models in a hierarchical framework, we modeled the distributions of 138 species. First, we trained the models for the entire Argentinean Chaco with climatic and topographic variables. Second, we modeled the same species for the NADC including the biophysical variables identified as relevant in the first step plus four LULC-related variables: woody biomass, distance to crops, density of livestock-based rural settlements (puestos), and vegetation cover. Third, we constructed species richness maps by adding the models of individual species and considering two situations, with and without LULC variables. Four, richness maps were used for assessing differences when LULC variables are added and for determining the main drivers of current patterns of species richness. We found a marked decrease in species richness of the four groups as a consequence of inclusion of LULC variables in distribution models. The main factors associated with current richness distribution patterns (both negatively) were woody biomass and density of livestock puestos. Species richness in present-day Semiarid Chaco landscapes is strongly affected by LULC patterns, even in areas not transformed to agriculture. Regional-scale biodiversity planning should consider open habitats such as grasslands and savannas in addition to woodlands.

Regional‐scale effects of eutrophication on ecosystem structure and services of seagrass beds

Using large‐scale field surveys across 12 estuaries in two provinces in Atlantic Canada, we analyzed changes in phytoplankton and benthic macroalgal communities as well as the canopy structure of eelgrass beds and quantified their carbon and nitrogen storage with increasing eutrophication. As eutrophication increased, phytoplankton biomass increased on average 1.8 times and phaeopigments doubled. Among macroalgae, the epiphytic Ulothrix speciosa increased 40 times in New Brunswick, and benthic Ulva lactuca 670 times in Prince Edward Island covering 61% of the bottom. Eelgrass showed a significant increase in leaf length and declines in shoot density and aboveground and belowground biomass, consistent with increased shading by opportunistic algae. As eelgrass biomass declined, so did the carbon storage capacity of the habitat. Nitrogen storage only declined in belowground eelgrass beds due to increasing tissue nitrogen content above ground with eutrophication. Despite province‐ and species‐specific responses of primary producers to nutrient loading, principal component analysis revealed an overall shift from perennial eelgrass to opportunistic macroalgae and phytoplankton with eutrophication at the regional scale, indicating generalized eutrophication effects on primary producer assemblages.

Bioengineers and their associated fauna respond differently to the effects of biogeography and upwelling

Temperature and primary production (often linked to nutrient supply) are two of the few factors influencing species diversity and abundances across mesoscale gradients, while at smaller scales the habitat complexity offered by bioengineers is important. Previous studies have illustrated effects of upwelling and biogeography on intertidal bioengineers, but it is not known if these processes influence assemblages associated with those bioengineers in a similar way. We examined the habitat structure offered by two species of mussels and their associated fauna in five regions across 3000 km and three biogeographic provinces of the South African coast, replicating upwelling and non-upwelling areas within each region. Upwelling and region influenced the structure of mussel beds (the density and size of mussels). In contrast, upwelling did not influence mesoscale differences in composition, abundance, and numbers of species of crustaceans, mollusks, or polychaetes in mussel beds. Regardless of trophic level or mode of reproduction, mussel bed fauna were influenced only by region. Regional differences were strongly influenced by biogeography. The associated fauna was, however, also strongly correlated with the structure of the habitats created by mussels. Our results support the importance of upwelling to a critical ecosystem engineer, but show that these effects do not extend directly to the assemblages of associated fauna, which are more influenced by regional-scale effects and biogeography. We suggest that mesoscale patterns in the associated fauna of this bioengineered habitat are driven by the direct effects of biogeography, combined with the influence of biogeography and upwelling on mussel bed structure.

Effect of Hurricane Ivan on Coastal Dunes of Santa Rosa Barrier Island, Florida: Characterized on the Basis of Pre- and Poststorm LIDAR Surveys

Abstract Santa Rosa Island, situated along the northwestern Florida coast facing the Gulf of Mexico, is an 85-km-long wave-dominated low-lying barrier island with well-developed incipient and established dunes. In this paper, we examine the regional-scale effect on coastal dunes by a strong category 3 hurricane, Ivan, through comparison of pre- and poststorm airborne LIDAR (light detecting and ranging) surveys. On the basis of pre-Ivan LIDAR survey data, the elevation of the berm and back beach is typically 2.0 m above MSL (mean sea level). Incipient dunes range from 2.5 to 10 m above MSL, or 0.5 to 8.0 m above the surrounding beach. The hummocky dunes that developed over relic washover platforms are typically less than 4.0 m above MSL. The densely vegetated, established dune fields are composed of dunes less than 7.0 m high and intradune wetlands lying at less than 1.0 m above MSL. The entire island was severely affected by Ivan, which made landfall about 45 km to the west in September 2004. The landscap...

Bioenergy Sustainability at the Regional Scale

The establishment of bioenergy crops will affect ecological processes and their interactions and thus have an influence on ecosystem services provided by the lands on which these crops are grown. The regional-scale effects of bioenergy choices on ecosystem services need special attention because they often have been neglected yet can affect the ecological, social and economic aspects of sustainability. A regional-scale perspective provides the opportunity to make more informed choices about crop selection and management, particularly with regard to water quality and quantity issues, and also about other aspects of ecological, social, and economic sustainability. We give special attention to cellulosic feedstocks because of the opportunities they provide.