Emerging global role of small lakes and ponds : little things mean a lot

Until recently, small continental waters have been completely ignored in virtually all global processes and cycles. This has resulted from the neglect of these systems and processes by ecologists and the assumption that ecosystems with a small areal extent cannot play a major role in global processes. Recent inventories based on modern geographical and mathematical approaches have shown that continental waters occupy nearly twice as much area as was previously believed. Further, these inventories have shown that small lakes and ponds dominate the areal extent of continental waters, correcting a centurylong misconception that large lakes are most important. The global importance of any ecosystem type in a process or cycle is the product of the areal extent and the intensity of the process in those ecosystems. Several analyses have shown the disproportionately great intensity of many processes in small aquatic ecosystems, indicating that they play an unexpectedly major role in global cycles. Assessments of the global carbon cycle underscore the need for aquatic scientists to view their work on a global scale in order to respond to the Earth's most pressing environmental problems.Hasta muy recientemente, las aguas continentales de pequeño volumen se han ignorado completamente en todos los procesos y ciclos globales. Esto ha sido el resultado de la poca consideración de estos ecosistemas y procesos por los ecólogos y de asumir que los ecosistemas que ocupan un área pequeña no juegan ningún papel importante en los procesos globales. Inventarios recientes basados en aproximaciones geográficas y matemáticas modernas indican que las aguas continentales ocupan casi el doble del área de lo que se creía anteriormente. Además, estos inventarios han mostrado que las charcas y lagunas de pequeñas dimensiones predominan en la extensión superficial de las aguas continentales, corrigiendo la concepción equivocada de todo un siglo de que los grandes lagos eran los más importantes. La importancia global de cualquier tipo de ecosistema en un proceso o ciclo es el producto de su superficie por la intensidad del proceso en el ecosistema. Diversos análisis han mostrado la intensidad desproporcionadamente grande de muchos procesos en los pequeños sistemas acuáticos, indicando su sorprendente papel primordial en los ciclos globales. Evaluaciones del ciclo global del carbono ponen de manifesto la necesidad de que los ecólogos acuáticos tengan una visión de su trabajo a escala global, para poder responder a los problemas ambientales más preocupantes

The Role of Water Quality Perceptions in Modeling Lake Recreation Demand

Recreation demand models typically incorporate measures of the physical attributes of recreational sites; e.g., Secchi depth or phosphorous levels in case of water quality. Moreover, most studies show that individuals do respond to these physical characteristics in choosing where to recreate. However, the question remains as to whether the available physical measures accurately capture individual perceptions of water quality and if there is a additional role to be played by elicited perception measures in modeling recreation demand. In this paper, we use data from the 2004 Iowa Lakes Survey to model recreation demand as a function of both the physical water quality at 131 lakes in the state and household perceptions of lake water quality. In general, water quality perceptions are correlated with the available physical measures, but not perfectly so, and both actual and perceived water quality are found to significantly impact recreational site choice.

Valuing Water Quality As a Functionof Water Quality Measures

This paper incorporates a rich set of physical water quality attributes, as well as site and household characteristics, into a model of recreational lake usage in Iowa. Our analysis shows individuals are responsive to physical water quality measures. Willingness-to-pay estimates are reported based on improvements in these measures.

The Geology and Mineral Deposits of British Columbia

The province of British Columbia, with an area of 359,279 square miles, includes a large part of the Canadian Cordillera that is the western mountains of Canada. It is the leading province of Canada in the production of lead, zinc, and silver, and third among the provinces in the output of gold, copper, and coal

Val Houston Smith (1950–2016): empiricism in the service of theory

This special collection in Inland Waters honors a most friendly, kind, and caring colleague (Fig. 1) who has made huge contributions to limnology, many other biological and geophysical sciences, and the fabric of the science communit

Electrostatic and Functional Analysis of the Seven-Bladed WD β-Propellers

β-propeller domains composed of WD repeats are highly ubiquitous and typically used as multi-site docking platforms to coordinate and integrate the activities of groups of proteins. Here, we have used extensive homology modelling of the WD40-repeat family of seven-bladed β-propellers coupled with subsequent structural classification and clustering of these models to define subfamilies of β-propellers with common structural, and probable, functional characteristics. We show that it is possible to assign seven-bladed WD β-propeller proteins into functionally different groups based on the information gained from homology modelling. We examine general structural diversity within the WD40-repeat family of seven-bladed β-propellers and demonstrate that seven-bladed β-propellers composed of WD-repeats are structurally distinct from other seven-bladed β-propellers. We further provide some insights into the multifunctional diversity of the seven-bladed WD β-propeller surfaces. This report once again reinforces the importance of structural data and the usefulness of homology models in functional classification

Carbon dioxide concentrations in eutrophic lakes: undersaturation implies atmospheric uptake

Understanding concentrations and contributions of carbon dioxide (CO2) in aquatic ecosystems is an important part of a comprehensive global carbon budget. Current dogma suggests that world lakes are important emitters of CO2 to the atmosphere. We estimated the partial pressure of carbon dioxide (ρCO2) in 131 agriculturally eutrophic lakes over a 7 year sampling period. Values of ρCO2 in these lakes ranged from 0.1 to 40 392 μatm with a median of 322 μatm (n = 3049). In contrast to previous analyses of CO2 in lakes, 60% of the eutrophic lake samples were undersaturated with CO2. Correlation analysis implied that nutrient-driven primary production, reflected by high oxygen concentra­tions, drives CO2 concentrations below atmospheric equilibrium. Multiple regression analysis showed several limno­logical and catchment characteristics that explained a statistically significant amount of variability in ρCO2 (R2 = 0.32). Important variables included chlorophyll a concentration and the ratio of total nitrogen to total phosphorus. Our estimated ρCO2 values were significantly (p < 0.0001) lower than a previously published dataset of world lake ρCO2 values derived primarily from oligotrophic-mesotrophic lakes. High-nutrient lakes, especially those that are small and rich in oxygen from primary production, could act as net atmospheric CO2 uptake sites