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951.
Ana Espínola-Arredondo Félix Muñoz-García 《Journal of Environmental Economics and Management》2011,62(3):402-413
This paper analyzes the protection of a common pool resource (CPR) through the management of information. Specifically, we examine an entry deterrence model between an incumbent perfectly informed about the initial stock of a CPR and an uninformed potential entrant. In our model, the appropriation of the CPR by the incumbent reduces both players' future profits from exploiting the resource. In the case of complete information, we show that the incumbent operating in a high-stock common pool overexploits the CPR during the first period since it does not internalize the negative external effect that its first-period exploitation imposes on the entrant's future profits. This inefficiency, however, is absent when the commons totally regenerate across periods. Under incomplete information, we identify an additional form of inefficiency. In particular, the incumbent operating in a low-stock CPR underexploits the resource in order to signal the low available stock to potential entrants, deterring entry. 相似文献
952.
Tree cover in sub-Saharan Africa: rainfall and fire constrain forest and savanna as alternative stable states 总被引:1,自引:0,他引:1
Savannas are known as ecosystems with tree cover below climate-defined equilibrium values. However, a predictive framework for understanding constraints on tree cover is lacking. We present (a) a spatially extensive analysis of tree cover and fire distribution in sub-Saharan Africa, and (b) a model, based on empirical results, demonstrating that savanna and forest may be alternative stable states in parts of Africa, with implications for understanding savanna distributions. Tree cover does not increase continuously with rainfall, but rather is constrained to low (<50%, "savanna") or high tree cover (>75%, "forest"). Intermediate tree cover rarely occurs. Fire, which prevents trees from establishing, differentiates high and low tree cover, especially in areas with rainfall between 1000 mm and 2000 mm. Fire is less important at low rainfall (<1000 mm), where rainfall limits tree cover, and at high rainfall (>2000 mm), where fire is rare. This pattern suggests that complex interactions between climate and disturbance produce emergent alternative states in tree cover. The relationship between tree cover and fire was incorporated into a dynamic model including grass, savanna tree saplings, and savanna trees. Only recruitment from sapling to adult tree varied depending on the amount of grass in the system. Based on our empirical analysis and previous work, fires spread only at tree cover of 40% or less, producing a sigmoidal fire probability distribution as a function of grass cover and therefore a sigmoidal sapling to tree recruitment function. This model demonstrates that, given relatively conservative and empirically supported assumptions about the establishment of trees in savannas, alternative stable states for the same set of environmental conditions (i.e., model parameters) are possible via a fire feedback mechanism. Integrating alternative stable state dynamics into models of biome distributions could improve our ability to predict changes in biome distributions and in carbon storage under climate and global change scenarios. 相似文献
953.
Rupert Seidl Paulo M. Fernandes Teresa F. FonsecaFrançois Gillet Anna Maria JönssonKatarína Mergani?ová Sigrid NethererAlexander Arpaci Jean-Daniel BontempsHarald Bugmann Jose Ramon González-OlabarriaPetra Lasch Céline MeredieuFrancisco Moreira Mart-Jan SchelhaasFrits Mohren 《Ecological modelling》2011,222(4):903-924
954.
Remote sensing has been used from the 1980s to study inland water quality. However, it was not until the beginning of the twenty-first century that CHRIS (an experimental multi-angle sensor with good spectral and spatial resolutions) and MERIS (with good temporal and spectral resolutions) started to acquire imagery with very good resolutions, which allowed to develop a reliable imagery acquisition system so as to consider remote sensing as an inland water management tool. This paper presents the methodology developed, from the field data acquisition with which to build a freshwater spectral library and the study of different atmospheric correction systems for CHRIS mode 2 and MERIS images, to the development of algorithms to determine chlorophyll-a and phycocyanin concentrations and bloom sites. All these algorithms allow determining water eutrophic and ecological states, apart from generating surveillance maps of toxic cyanobacteria with the main objective of Assessment of the Water Quality as it was used for Monitoring Ecological Water Quality in smallest Mediterranean Reservoirs integrated in the Intercalibration Exercise of European Union Water Framework Directive (WFD). We keep on using it to monitor the Ecological Quality Ratio (EQR) in Spain inland water. 相似文献
955.
Oscar Amin Laura Comoglio Carla Spetter Claudia Duarte Ra��l Asteasuain Rub��n Hugo Freije Jorge Marcovecchio 《Environmental monitoring and assessment》2011,175(1-4):63-73
The study deals with the determination of physico-chemical parameters, inorganic nutrients, particulate organic matter, and photosynthetic pigments on a monthly basis during an annual cycle from nine sampling sites of the coastal zone of a high-latitude ecosystem (Tierra del Fuego, Argentina). Nitrites and phosphates concentrations were similar to other systems of the south Atlantic coast (median, 0.30 and 1.02 ??M, respectively), while nitrates were higher in all sampling periods (median, 45.37 ??M), and silicates were significantly smaller (median, 7.76 ??M). Chlorophyll a and phaeopigments have shown median values of 0.38 and 0.85 mg m???3, respectively, while saturated values of dissolved oxygen were recorded throughout the study. The analysis reflected that nutrient enrichment seems to be linked to an anthropogenic source, the presence of peatlands areas, and a sink of Nothofagus pumilio woods. The area could be characterized in three zones related to (1) high urban influence, (2) natural inputs of freshwater, and (3) mixed inputs coming from moderate urban impacts. 相似文献
956.
Fernandes Tiago A. Mendo Sofia G. Ferreira Liliana P. Neng Nuno R. Oliveira M. Conceição Gil Adrià Carvalho Maria Deus Monteiro Olinda C. Nogueira José M. F. Calhorda Maria José 《Environmental science and pollution research international》2021,28(14):17228-17243
Environmental Science and Pollution Research - The increased use of pharmaceutical and personal care products (PPCPs) has contributed to the contamination of water systems and put pressure on the... 相似文献
957.
Eiró Luciana Guimarães Ferreira Maria Karolina Martins Frazão Déborah Ribeiro Aragão Walessa Alana Bragança Souza-Rodrigues Renata Duarte Fagundes Nathalia Carolina Fernandes Maia Lucianne Cople Lima Rafael Rodrigues 《Environmental science and pollution research international》2021,28(28):37001-37015
Environmental Science and Pollution Research - Lead (Pb) is one of the most toxic and abundant elements in the earth’s crust, which is pointed out that the intoxication caused by it... 相似文献
958.
Lopez Carla Nnorom Mac-Anthony Tsang Yiu Fai Knapp Charles W. 《Environmental science and pollution research international》2021,28(43):60968-60980
Environmental Science and Pollution Research - The impact of pharmaceutical and personal care products (PPCPs) on the performance of biological wastewater treatment plants (WWTPs) has been widely... 相似文献
959.
Gálvez-Iriqui Alma Carolina García-Romo Joel Said Cortez-Rocha Mario Onofre Burgos-Hernández Armando Burboa-Zazueta María Guadalupe Luque-Alcaraz Ana Guadalupe Calderón-Santoyo Montserrat Argüelles-Monal Waldo Manuel Plascencia-Jatomea Maribel 《Environmental science and pollution research international》2021,28(3):3051-3065
Environmental Science and Pollution Research - Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo... 相似文献