Metabolic activity and elemental composition of krill and other zooplankton from Prydz Bay,Antarctica, during early summer (November–December)

Oxygen uptake and ammonia excretion rates, and body carbon and nitrogen contents were measured in krill (Euphausia superba) and eight other zooplankton species collected during November–December 1982 in the Prydz Bay, Antarctica. From these data, metabolic O:N ratios (by atoms), body C:N ratios (by weight) and daily metabolic losses of body carbon and nitrogen were calculated as a basis from which to evaluate seasonal differences in metabolism and nutritional condition. Comparison of the present data with mid-summer (January) data revealed that early-summer E. superba were characterized by higher metabolic O:N ratios (58.7 to 103, compared with 15.9 to 17.5 for mid-summer individuals). Higher O:N ratios of early-summer E. superba resulted largely from reduced ammonia excretion rates and, to a lesser degree, from slightly increased oxygen uptake rates. Body C:N ratios of E. superba were low in early-summer (3.8 to 4.2) compared with mid-summer krill (4.1 to 4.7) due to lowered body-carbon contents in the former (42.6 to 43.6% compared with 43.2 to 47.5% dry weight of midsummer individuals); gravid females formed an exception, since no seasonal differences in body elemental composition were detected for these. No significant changes in water content (75.3 to 81.4% wet wt) and nitrogen content (9.9 to 11.1% dry wt) in E. superba were evident between the two seasons. Seasonal differences in metabolic rates and elemental composition were less pronounced in a salp (Salpa thompsoni), but a higher metabolic O:N ratio occurred in early-summer individuals. Interspecific comparison of the seven remaining zooplankton species studied with twelve species from mid-summer zooplankton investigated in an earlier study indicated that higher metabolic O:N ratios in early-summer are characteristic not only of herbivore/filter-feeders, but also of some carnivores/omnivores. No relationship between metabolic O:N ratios and body C:N ratios was apparent either intraspecifically or interspecifically, within or between early-summer and mid-summer seasons.     

Measurement of organic compound emission using small test chambers

Organic compounds emitted from a variety of indoor materials have been measured using small (166 L) environmental test chambers. The paper discusses: a) factors to be considered in small chamber testing; b) parameters to be controlled; c) the types of results obtained. The following types of materials have been tested: adhesives, caulks, pressed wood products, floor waxes, paints, and solid insecticides. Selected data are presented. For each material, chamber concentrations of organic compounds have been determined for a range of environmental conditions (e.g., air exchange rate, temperature and relative humidity). Emission rates for individual organic compounds, as well as total measured organics, were calculated. The effects of environmental variables on emission rates have been evaluated. Models are used to evaluate the effect of chamber walls and concentration on emission rates.     

Integrated mite control in apples in Queensland, Australia

An interdisciplinary team introduced Integrated Mite Control (IMC) to the Queensland apple industry in Australia from 1989 to 1992. Project funding supported the employment of a consultant to monitor mite levels and provide management advice to growers who paid for the service. Interviews at the beginning and end of the project showed widespread adoption of IMC over this period. Overall use of chemicals was not reduced, but the use pattern changed towards wider use of chemicals that are less toxic to predatory mites. The future of IMC in the Queensland apple industry is in doubt because the seasonal nature of apple production does not allow the paid consultancy service to be self-sustaining. Indications are that the integrated approach to pest management may not be generally accepted as a strategic management process while the availability of effective chemicals allows the continuation of a spray routine for mite control. The lack of availability of effective and proven methods of pest control was seen by growers as the major constraint to adoption of IMC.     

Agricultural Production Monitoring in the Sahel Using Remote Sensing: Present Possibilities and Research Needs

The main objective is to review the current status of research related to the monitoring of agricultural production in the Sahel (west Africa). The Sahel suffers from frequent shortages of food. It is therefore important to have a tool to monitor environmental variables, and thus crop production, during the agricultural season. Satellite remote sensing can contribute significantly to such a system by collecting information on crops and on environmental variables at a sub-continental geographical scale and with a high temporal frequency. One part of the problem is to estimate crop acreage. The technique of area-sampling frame has to adapted to the Sahelian landscape, which is dominated by traditional farming systems. The second part is to estimate crop yields. Three main approaches exist: statistical, semi-deterministic or deterministic. The use of vegetation indices is discussed as well as techniques to derive biophysical variables from remotely-sensed data. Finally, the integration of these remote-sensing techniques with crop-growth models is discussed and some research needs are identified. It is argued that the quantitative assessment of agricultural production in the Sahel should be based on the integration of remotely-sensed data with semi-deterministic agrometeorological models. This approach will allow a regionalization of the production estimates.     

LUMP SUM TAX LOSS REIMBURSEMENT UNDER THE THAMES RIVER FLOOD CONTROL COMPACT1

ABSTRACT: Under the terms of the Thames River Valley Flood Control Compact, Connecticut has been paying Massachusetts 40 percent of the annual property tax losses suffered by seven Massachusetts towns where four flood control structures were located. The permissable alternative of a single lump sum payment was investigated in the study summarized here. The lump sum payment should be the proportion of total benefits (flood control and recreation) from the four structures which Connecticut receives, multiplied by the present value of projected tax losses in the seven tom Flood control benefits and their distribution between the two states were fixed in the Compact, but a survey was necessary to determine recreational benefits and their distribution. Regression analysis of 1957 to 1978 tax loss data provided equations used to project future tax losses. Resent values of projected tax low were calculated using discount rates ranging from 6 to 12 percent. A plausible range of lump sum reinbursements as of 1979 was identified.     

Measures of energy cost and value in ecosystems

The physical output of ecological processes have different values even though they may be measured in the same physical units. Using linear input-output theory, we derive a set of weights based on direct and indirect energy requirements for ecosystem commodities which uniquely converts them into commensurable unit costs. Under certain conditions, these costs are equal to values or prices. Using this system, behavioral theories can be better posed for experimental verification.     

Federalism and environmental politics: An Australian overview

Summary This overview paper examines past Australian conservation controversies and experiences to identify prospective means of ameliorating environmental conflict in the future. Since all community disputes should be resolved by means of political and administrative actions, emphasis is placed on federalism and intergovernmental relations, and measures are suggested which might improve environmental policy and practices in the future.Dr Bruce W. Davis is currently Head of the Department of Political Science, Dean of the Faculty of Arts, and member of the Council of the University of Tasmania. He possesses qualifications and professional experience in engineering, economics and administration. He has numerous publications within the fields of public sector planning and natural resources management, and acts in an advisory and consulting capacity to State and Federal agencies involved in national parks administration, heritage conservation and land-use planning.In addition to University commitments, Dr Davis holds the following appointments: Commissioner, Australian Heritage Commission; Member, Australian National Commission for UNESCO, Man and Biosphere Program; Trustee, World Wildlife Fund Australia; Councillor, Australian Conservation Foundation; and Consultant to IUCN, Gland, Switzerland.     

AN AUTOMATED RECORDING SYSTEM FOR EVAPORATION PANS1

ABSTRACT: ABSTRACT: An automated recording system for evaporation pans was developed to allow continuous analog type recording of pan evaporation. The system incorporates a water reservoir to supply water to the pan and can be left unattended for long periods of time. The system performed well, with very little maintenance, in a field test in northern Utah.     

AN APPLICATION OF MATHEMATICAL PROGRAMMING TO WATER RESOURCES PLANNING: AN ECONOMIC VIEW1

ABSTRACT: Individuals involved in state water resource planning generally have avoided any development of a comprehensive public water planning investment model that would set the stage for quantitative recommendations of a “what ought to be” tone for future water strategies. Three New Hampshire towns were selected to illustrate the usefulness of a mixed integer multiperiod programming model that utilizes hydrologic and economic data for identifying the discounted least cost of water supply, distribution, and scheduling. Comparisons are made regarding the feasibility of a regional water system approach versus independent “town by town” water supplies that presently prevail. To analyze the sensitivity of optimal water planning solutions to projected water demands, variations in these demands are made.