Abstract: We determined reference hydro-climatic and land use/cover sensitivities of stormwater runoff and quality in the Miami River Basin of Florida by developing a dynamic rainfall-runoff model with the EPA Storm Water Management Model. Potential storm runoff in the complex coastal-urban basin exhibited high and notably different seasonal sensitivities to rainfall; with stronger responses in the drier early winter and wetter late summer months. Basin runoff and pollutant loads showed moderate sensitivities to the hydrologic and land cover parameters; imperviousness and roughness exhibited more dominant influence than slope. Sensitivity to potential changes in land use patterns was relatively low. The changes in runoff and pollutants under simultaneous hydro-climatic or climate-land use perturbations were notably different than the summations of their individual contributions. The quantified sensitivities can be useful for appropriate management of stormwater quantity and quality in complex urban basins under a changing climate, land use/cover, and hydrology around the world.

Abstract: The long-term fate of populations experiencing disequilibrium conditions with their environment will ultimately depend on how local colonization and extinction dynamics respond to abiotic conditions (e.g. temperature and rainfall), dispersal limitation and biotic interactions (e.g. competition, facilitation or interactions with natural enemies). Understanding how these factors influence distributional dynamics under climate change is a major knowledge gap, particularly for small ranged and dispersal-limited plant species, which are at higher risk of extinction. Epiphytes are hypothesized to be particularly vulnerable to climate change and we know little about what drives their distribution and how they will respond to climate change. To address this issue, we leveraged a 10-year dataset on the occupancy dynamics of the endemic orchid Lepanthes rupestris to identify the drivers of local colonization and extinction dynamics and assess the long-term fate of this population under multiple climate change scenarios. We compared 290 dynamic occupancy models in their ability to predict the colonization and extinction dynamics of a L. rupestris metapopulation. The model set predicted colonization-extinction dynamics as a function of asymmetric patch connectivity, moss area, elevation, temperature (minimum, maximum and variability) and/or rainfall. The best model predicted that local colonization increases with increasing asymmetric patch connectivity but decreases as minimum temperature and maximum temperature variability increase. The best model also predicted that local extinction increases with increasing variability in maximum temperature. Negative effects were more severe in smaller patches. Synthesis. Overall, our results demonstrate the role of asymmetric connectivity, climate and interactions with moss area as drivers of colonization and extinction dynamics. Moreover, our results suggest that asymmetrically dispersed epiphytes may struggle to persist under climate change because their limited connectivity may not be enough to counterbalance the negative effects of increasing mean or variability in temperature.

Abstract: Global change stressors such as drought and plant invasion can affect ecosystem structure and function via mediation of resource availability and plant competition outcomes. Yet, it remains uncertain how native plants respond to drought stress that co-occurs with potentially novel resource conditions created by a nonnative invader. Further, there is likely to be temporal variation in competition outcomes between native and nonnative plant species depending on which resources are most limiting at a given time. Interacting stressors coupled with temporal variation make it difficult to predict how global change will impact native plant communities. To address this knowledge gap, we conducted a 5-yr factorial field experiment to quantify how simulated drought, plant invasion (by cogongrass, Imperata cylindrica), and these stressors combined, affected resource availability (soil moisture and light) and competition dynamics between the invader and native longleaf pine (Pinus palustris), a foundation species in southeast U.S. forests. Drought and invasion mediated the survival and performance of pine seedlings in temporally dynamic and unexpected ways. Drought and invasion alone each significantly reduced pine seedling survival. However, when the stressors occurred together, the invader offset drought stress for pine seedlings by maintaining high levels of soil moisture, humidity, and shade compared to uninvaded vegetation. This facilitative effect was pronounced for 2 yr, yet shifted to strong competitive exclusion as the invasion progressed and the limiting resource switched from soil moisture to light. After 3 yr, pine tree survival was low except for pines growing with uninvaded vegetation under ambient precipitation conditions. After 5 yr, pines experiencing a single stressor were taller and had greater height to diameter ratios than pines under no stress or both stressors. This outcome revealed a filtering effect where poorly performing trees were culled under stressful conditions, especially when pines were growing with the invader. Together, these results demonstrate that although drought and invasion suppressed a foundation tree species, the invader temporarily moderated stressful drought conditions, and at least some trees were able to survive despite increasingly strong competition. Such unpredictable effects of interacting global change stressors on native plant species highlight the need for additional long-term studies.

Abstract: Trends and variability of the climate in the southeastern United States, including Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, and Tennessee was studied for an array of future scenarios in the 21st century. The region is a biodiversity hotspot affected by more billion-dollar disasters than any other region in the country. Assessing the impacts of climate change in southeastern United States is important and often requires knowledge of plausible future climate change (e.g. scenarios of temperature and precipitation change). Although several methods are available in literature to develop plausible scenarios of the changes, there exists a usability gap [gap between what scientists understand as useful information and what users recognize as usable]. A novel conceptual framework that represents the plausible future climate change scenarios in southeastern United States was developed using information from meta-analysis and outputs from similar to 19 Coupled Model Intercomparison Project (CMIP5) Global Climate Models (GCMs) [data analysis] in the form of scenario funnels (represent the plausible trajectories of changes in climate). The systematic literature review provided 33 values of precipitation changes from 15 studies and 35 for temperature changes from 14 studies. In general, the meta-analysis revealed, the precipitation changes observed ranged from -30 to + 35% and temperature changes between - 2 degrees C to 6 degrees C by 2099. Fiftieth percentile of the GCMs predicts no precipitation change and an increase of 2.5 degrees C temperature in the region by 2099. Among the GCMs, 5th and 95th percentile of precipitation changes range between - 40% to 110% and temperature changes between - 2 degrees C to 6 degrees C by 2099. Finally, the usability of scenario information to stakeholders in various southeastern United States ecosystems and guidelines for developing causal chains and feedback loops with three levels of complexity were provided. They include utilizing the information from impact assessment studies, stakeholder's expertise and requirement as well as understanding the potential impacts in ecosystems (e.g. agroecosystems, coastal, wetland) by relating the structural components of an ecosystem, their interactions with each other, within and across ecosystems for improved management and sustainable use of their resources. These would improve understanding of ecosystem functioning for better management and sustainable use of resources. Although the methodology was demonstrated for southeastern United States, it could also be applicable to other regions of the world. However, the scenario funnels, potential impacts on ecosystems and causal chain/loops are subjective to the study region, availability of literature, the changes observed in the literature and data analyzed, the characteristics of the study region, the stakeholder and their requirement.

Abstract: Extended periods with excessive or no rainfall or high or low temperatures have important implications on the water cycle, can stress ecosystems and can be detrimental to the economy of a region. These periods are generally studied using spell length indicators or duration indices (SDIs). Fourteen SDIs are calculated to study the changes in wet/dry/warm/cold spells using daily precipitation and maximum and minimum air temperature from 23 centennial weather stations spread across Kansas during four time periods (through 1920, 1921�1950, 1951�1980 and 1981�2009) and two temporal scales (annual and seasonal). Among the SDIs, 3 represent wet spells [wet spell length (WetSL); AvWetSL; MaxWetSL]; 3 for dry spells [dry spell length (DrySL); AvDrySL; MaxDrySL]; 4 for warm spells [warm spell length (WarmSL); average warm spell length (AvWarmSL); maximum warm spell length (MaxWarmSL); WarmSDI] and 4 are for cold spells [cold spell length (ColdSL); average cold spell length (AvColdSL); maximum cold spell length (MaxColdSL); ColdSDI]. In general, we observe that Kansas has 57�64 days year−1 in a wet spell; 302�309 days year−1 in a dry spell; ∼47 days year−1 in each warm and cold spells. The average length of a wet/dry spell is ∼1.5 days, while the warm/cold spells are for 2 days. The maximum length of a wet spell is ∼4.4 days, a dry spell is ∼35 days and warm/cold spells is ∼6 days. We found the number of wet days increasing annually. Interestingly, the warm days during winter are increasing with an overall decrease in the days in warm and cold spells across both temporal scales.

Abstract: In recent years there has been a significant increase in the prevalence of allergic diseases despite advances in the understanding of the pathogenesis, the dissemination of guidelines for its management and the emergence of new drugs. The reasons for this increase are not fully established, but it is suggested that multiple environmental factors may be involved. Inhaled air contains numerous harmful agents in addition to environmental allergens. The main immediate respiratory clinical expression after inhaling this contaminated air is asthma and rhinitis. The activity of human beings has altered the outdoor environment by the emission of multiple pollutants and has produced an increasing climate change. It also has a notable impact on the development of respiratory pathology and the modification of air quality. The bibliography on the subject of environmental control is very broad and sometimes difficult to interpret. In order to be able to make precise, valid and simple indications for patients to accomplish with, four scientific societies of the Argentine Republic that deal with this type of diseases, have elaborated a document that contains information of easy access to all medical personal involved in the treatment of patients with asthma and / or rhinitis, that provides practical measures for the patients and the different public health systems about unmet needs in this complex issue.

Abstract: Hydrogen and carbon isotope values (δD & δ13C) were measured on lipid biomarkers from a sediment core collected in Lake Tulane, Florida, USA, to infer shifts in climate and hydrologic variables during the Last Glacial. Isotopic trends from 24 samples correlate with plant community shifts evaluated in a previous pollen study by Grimm et al. (2006). We observe maxima in Δleaf values and minima in δD values concurrent with peaks in Pinus pollen abundances and Heinrich Events 4-2. Increased Δleaf values during North Atlantic cold spells indicate lower water-use-efficiency among angiosperms around Lake Tulane. Combined δD values from terrestrial and aquatic lipids, confirm that aridity decreased during cold, stadial periods (Heinrich Events), and increased during warm, interstadials. Furthermore, lower δD values in aquatic lipids during stadials are attributed to warming, as well as changing moisture sources. The anti-phase relationship between temperatures and aridity derived from our subtropical lacustrine record and those at high latitude in the North Atlantic is likely the result of complex ocean-atmosphere teleconnections that resulted from the collapse of Atlantic Meridional Overturning Circulation during Heinrich Events in the North Atlantic.