LONG-TERM EQUILIBRIUM PHOSPHORUS CONCENTRATIONS IN THE EVERGLADES AS PREDICTED BY A VOLLENWEIDER-TYPE MODEL1

ABSTRACT: Anthropogenic phosphorus loading, mainly from the Everglades Agricultural Area (EAA), is believed to be the primary cause of eutrophication in the Everglades. The state of Florida has adopted a plan for addressing Everglades eutrophication problems by reducing anthropogenic phosphorus loads through the implementation of Best Management Practices (BMPs) in agricultural watersheds and the construction of stormwater treatment areas (STAs). Optimizing the effectiveness of these STAs for reducing phosphorus concentrations from agricultural runoff is a critical component of the District's comprehensive Everglades protection effort. Therefore, the objective of this study was to develop a simple tool that can be used to estimate STAs’performance and evaluate management alternatives considered in the Everglades restoration efforts. The model was tested at two south Florida wetland sites and then was used to simulate several management alternatives and predict ecosystem responses to reduced external phosphorus (P) loadings. Good agreement between model predictions at the two wetland sites and actual observations indicated that the model can be used as a management tool to predict wetlands’response to reductions in external phosphorus load and long-term P levels in aquatic ecosystems. Model results showed that lowering P content of the Everglades Protection Area (EPA) depends on reducing P loads originating from EAA discharges, not from rainfall. Assuming no action is taken (e.g., no BMPs or STAs implemented), the steady state model predicted that the average concentration within the modeled area of the marsh would reach 20 μg L^?1 within five years. With an 85 percent reduction in P loading, the steady-state model predicted that Water Conservation Area 2A (WCA-2A) P concentration will equilibrate at approximately 10 μ L^?1, while elimination of all loadings is projected to further reduce marsh P to values less than 10 μg L^?1.     

Oil Funding and International Financial Arrangements

The traditional source of funds for exploration and development of petroleum resources has been privately-owned petroleum companies. However, many of these same companies have recently borrowed heavily to finance their acquisitions of other petroleum companies. This may limit the ability of those companies to finance future exploration and development efforts, particularly in developing countries. Special financial arrangements may be needed if the funds required are to be available. The form of such arrangements is discussed, and emphasis is placed on the need to reconcile the differing needs of borrowers and lenders.     

Copper, Copper Mining Effluents and Grazing as Potential Determinants of Algal Abundance and Diversity in Northern Chile

We experimentally tested threealternative hypotheses to explain the low algaldiversity and abundance in an intertidal zonereceiving the effluents of the copper mine El Salvadorin northern Chile. Our results demonstrated thatalgae were able to grow at the levels of dissolvedcopper detected in coastal waters of the area. Duringthe assays, growth and regeneration in several red,green and brown adult algae and juvenile Lessonia nigrescens were normal at copper levels of150 g L^-1 or, in some cases, higher. Wealso found that the coastal sea water mixed with theeffluent was not lethal to algae, although in somecases minor effects on growth were detected. Theseresults indicate that today's low algal diversity andabundance can not be explained by the current copperlevels in the area nor by the effect of the effluent.Exclusion of grazers, however, resulted in a fastcolonization by various algal species. This, togetherwith atypically high grazer density at the areas underthe influence of the effluent, strongly suggests thatherbivory, a factor not directly related to the miningoperation, is likely to be responsible for the lowalgal diversity and abundance in the studied locality.     

The Impact of NTFP Sales on Rural Households’ Cash Income in India’s Dry Deciduous Forest

In recent years, researchers and policy makers have recognized that nontimber forest products (NTFPs) extracted from forests by rural people can make a significant contribution to their well-being and to the local economy. This study presents and discusses data that describe the contribution of NTFPs to cash income in the dry deciduous forests of Orissa and Jharkhand, India. In its focus on cash income, this study sheds light on how the sale of NTFPs and products that use NTFPs as inputs contribute to the rural economy. From analysis of a unique data set that was collected over the course of a year, the study finds that the contribution of NTFPs to cash income varies across ecological settings, seasons, income level, and caste. Such variation should inform where and when to apply NTFP forest access and management policies.     

The Ecological and Environmental Characteristics and Conservation of the Wetlands in the Changjiang Estuary, China

The natural wetlands in the Changjiang Estuary, China are important ecologically. The total area of the wetlands in the Changjiang Estuary amounts to 215000 ha. The wetlands consist of littoral and sandy estuarine island areas, and are rich in biological resources. There are 136 species of vascular plant, 150 species of bird, and 68 species of benthic macro-invertebrate in the wetlands. However, the wetland in the Changjiang Estuary is a vulnerable ecosystem. Development of the wetland is mainly influenced by intensive human reclamation, pollution, movement of sediments in the Changjiang River, and the effects of tides and waves. Investigations have shown that maintaining biodiversity, providing resources for the living organisms, purifying environments and resisting natural hazards could be regarded as important functions for the protection of the wetlands. It is proposed that sustainable principles should be supported in developing the wetlands in the future.     

夹层电缆引发火灾的实验研究

模拟现代建筑夹层中贮藏大量未加金属导管防护的电线电缆所引发的火灾效应.在一个全尺寸燃烧套房模型中进行了起火室和顶棚夹层空间电缆火灾的实验研究,并采用大涡模拟的方法对实验中烟气速度场进行了数值模拟.结果表明,加明火源可以加强电缆的火灾功率;通风状况对夹层电缆火灾的温度场、烟气遮光度和火灾功率有明显影响.电缆燃烧产物中主要毒性气体为CO.电缆在夹层燃烧时,CO和CO2浓度均高于目标室和起火室中的浓度.而夹层毒气最为集中,其CO浓度远远超出OSHA和IDLH标准.电缆在夹层燃烧时发生火灾的危险性较大.     

Effect of Ecogeographic Factors along Latitudinal–Longitudinal Gradient on the Red Blood System of the Caucasian Snow Vole (Chionomys gud), a Species Autochthonous to the Caucasus

Russian Journal of Ecology - Parameters of hematopoietic tissue and peripheral blood in the Caucasian snow vole (Chionomys gud Satunin, 1909), a typical mountain species of small mammals, have been...     

An optimized artificial neural network model for the prediction of rate of hazardous chemical and healthcare waste generation at the national level

Journal of Material Cycles and Waste Management - This paper presents a development of general regression neural network (a form of artificial neural network) models for the prediction of annual...     

Are Landscape Configuration Metrics Worth Including When Predicting Specialist and Generalist Bird Species Density? A Case of the Generalised Additive Model Approach

Due to the complexity of factors that influence species density on a large geographical scale, the effectiveness of the species distribution model (SDM) is still debatable. That is why the buffer zone (the area within 100 m from the outside edge of the patch), the core, i.e. (patches excluding the 100 m buffer zone from the patch’s edge) and patch shape are explored in this study to see how they affect the density of habitat specialist and generalist bird species. Two sets of generalised additive models were generated separately for each of the four bird species: One set of models contained landscape configuration metrics as an additional predictor variable, and the other did not. The results showed that models including the core, the buffer zone and the shape of patches turned out to be definitely better than models without them. Specialist species, the Corn bunting and the Wood nuthatch, are more likely to occur in the core of the preferred patches, and they choose those of a simple shape; while generalist species, the Whinchat and the Tree pipit, are more probable to be present in the buffer zone of a more complicated shape. Thus, the results clearly show that specific landscape configuration models can improve the predictive power of SDMs and can be used as an effective tool for predicting species density and functional bird diversity (specialist and generalist). Furthermore, from the applied ecology perspective, detailed landscape configuration metrics can be considered as a surrogate of elusive habitat conditions.     

Genogeography of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. populations in the Greater Caucasus and Crimea

Allozyme analysis of 18 Pinus sylvestris L. populations from seven landscape-geographic groups has been performed in the Greater Caucasus, Crimea, and Russian Plain. The results show that populations of the Mt. Elbrus region (isolated by high mountain ridges) are characterized by lower polymorphism and most distinct differentiation (at the level of geographic race) from other populations, which are differentiated from each other at the level of geographic groups. Genetic gradients (boundaries) between populations reach a maximum on transects across the Greater Caucasus Range, and Transcaucasian populations are more similar to populations of the Russian Plain, compared to North Caucasian populations, which confirms the hypothesis of ancestral connections between their gene pools.