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Hydrophytes of the oases in the Sierra de la Giganta of Central Baja California Sur, Mexico: Floristic composition and conservation status 总被引：1，自引：0，他引：1
One of the features of the Sierra de la Giganta mountain range is the existence of many small riparian wetlands (oases) along drainage channels. There are no geohydrological studies from which to determine their dynamics in the arid environment, but these areas confront increasing water extraction to satisfy demands of small local settlements. This study compiled a checklist of the hydrophytes from 12 representative oases, and discusses their current status on the basis of composition, richness, and species characteristics. Floristic composition (absence–presence of 57 hydrophytes) at each location was classified by using UPGMA to represent a dendrogram of group cohesivity. Two major kinds of locations are present. By analysing individual site characteristics, we found that one group occurs in places under “good conservation conditions” and the other composed of locations that are “impacted” in several ways. The former group contains oases that are relatively rich in species, including most of the aquatic forms, which are sensitive to disturbance. Geographical affinity of the floristic list reveals that most species have a broad distribution, mostly in tropical America. 相似文献
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E. Cadena F. Adani X. Font A. Artola 《International Journal of Environmental Science and Technology》2018,15(10):2193-2202
Odors occupy a leading position among air quality issues of growing concern. Odors can be emitted from different economic sectors, from industrial to agricultural, including waste treatment activities. Although there are different techniques to determine odor emissions, a standardized indicator has not still been defined to include odor impact into methodological tools such as Life Cycle Assessment. In this sense, some proposals can be found in current literature. Considering these approaches, the present work proposes the Odor Impact Potential, an indicator to be used in Life Cycle Assessment or in waste treatment technologies benchmarking. A simple method is reported to calculate the Odor Impact Potential value from different types of data: chemical analysis of odorants or olfactometric determinations. Data obtained in a previous work for an industrial scale anaerobic digestion plant have been used to present an example of application. Additional Odor Impact Potential calculations from other published data (thermal waste treatment plant and wastewater treatment plant) are also included. The aim of Odor Impact Potential is not to replace parameters such as odor emission rates, odor concentration, or odor emission factors but to use those values to calculate the odor-derived impact in Life Cycle Assessment studies. 相似文献
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Pseudopterogorgia acerosa is the tallest gorgonian octocoral found in the Caribbean. In the Cartagena area, Colombia, P. acerosa is commonly harvested as raw material for handicrafts, rendering important the study of its growth and population dynamics. Growth measurements of branches from multiple colonies at two different reefs during 1 year revealed that the main growth was due to rapid elongation of the main (‘mother’) branch and production of daughter branches from the same (or just a few) mother branch(es). Some small colonies doubled their original size in a year. The branches’ absolute growth rate was weakly correlated with size, with no significant relationships between branch size and percent growth. While the pinnate branching pattern in P. acerosa is similar to its congeners Pseudopterogorgia elisabethae and Pseudopterogorgia bipinnata, it produces taller colonies due to the faster growth rate in the primordial mother branch. This growth mode seems advantageous as it augments exposure to light and higher fluxes of suspended food in the benthic boundary layer. Post‐harvesting, clipped colonies exhibited clear signs of regeneration, even in cases where only the holdfast remained. Pseudopterogorgia acerosa seems to have similar regeneration capabilities respect to other Pseudopterogorgia species, where regenerating colonies may grow faster than intact ones. 相似文献
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Late Pleistocene biota from Pubenza,Colombia; turtles,mammals, birds,invertebrates and plant remains
AndrÉs Alfonso-Rojas Laura M. Herrera-Gutierrez Catalina SuÁRez MartÍN R. Ciancio Jonathan S. Pelegrin Edwin-Alberto Cadena 《第四纪科学杂志》2021,36(3):450-466
Pubenza is a remarkable palaeontological site of Colombia, and a place that could hold some of the potentially oldest evidence of humans in northern South America. Previous palaeontological research at this site has mainly focused on the megafauna. Here we describe and establish the systematic palaeontology for the small fauna that inhabited this ancient lacustrine ecosystem, including the first report of birds, tortoises and vipers for the Late Pleistocene in Colombia. Furthermore, exceptionally well preserved fossilised wasp nests are morphologically and elementally characterised, which is the first report of an ichnofossil of this kind in northern South America. In addition, new material of kinosternid turtles, armadillos and rodents is also described. Our results reveal that the Bogotá River Basin, where Pubenza is located, was a rich ecosystem during the Late Pleistocene and a region of great interest for future articulated palaeontological and archaeological studies. 相似文献
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Craig L. Patterson Fernando Cadena Rajib Sinha Dzung Kim Ngo‐Kidd Abbas Ghassemi E. Radha Krishnan 《Ground Water Monitoring & Remediation》2013,33(2):44-52
Methyl‐tertiary butyl ether (MTBE) is often found in groundwater as a result of gasoline spills and leaking underground storage tanks. An extrapolation of occurrence data in 2008 estimated at least one detection of MTBE in approximately 165 small and large public water systems serving 896,000 people nationally (United States Environmental Protection Agency [U.S. EPA] 2008). The objective of this collaborative field study was to evaluate a small groundwater treatment system to determine the effectiveness of ultraviolet (UV)/ozone treatment in removing MTBE from contaminated drinking water wells. A pilot‐scale advanced oxidation process (AOP) system was tested to evaluate the oxidation efficiency of MTBE and intermediates under field conditions. This system used ozone as an oxidizer in the presence of UV light at hydraulic retention times varying from 1 to 3 min. MTBE removal efficiencies approaching 97% were possible with this system, even with low retention times. The intermediate t‐butyl alcohol (TBA) was removed to a lesser extent (71%) under the same test conditions. The main intermediate formed in the oxidation process of the contaminated groundwater in these studies was acetone. The concentrations of the other anticipated intermediates t‐butyl formate (TBF), isopropyl alcohol (IPA), methyl acetate (MAc), and possible co‐occurring aromatics (BTEX) in the effluent were negligible. 相似文献
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Shelley Gustafson Angela Joehl Cadena Chinh Cong Ngo Ammar Kawash Ienkate Saenghkaew Paul Hartman 《Climatic change》2018,149(1):91-106
Climate change is increasingly affecting rural areas worldwide. The Lower Mekong Basin (LMB) is at particular risk due to heat stress, changing rainfall patterns, rising sea levels, and more frequent and extreme climatic events. It is imperative that local-level adaptation plans are developed in a manner that builds resilience to these growing threats. Strategies for developing adaptation plans tend to comprise predominantly science-led or predominantly community-led processes. This study examines an approach that balances inputs from both processes in characterizing community vulnerability as a component of the adaptation planning workflow. Evaluation sites are located within four distinct sub-regions of the LMB: the Vietnam Mekong Delta, the Annamite Mountains of Lao PDR, the Cambodia central lowlands, and the mid-elevation forests of northern Thailand. Our results indicate that by merging science-based data with community-level perspective, knowledge gaps from both sides are filled and a more comprehensive understanding of vulnerability is factored into adaptation planning. 相似文献
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