A preliminary analysis of the correlation of food-web characteristics with hydrology and nutrient gradients in the southern Everglades

We estimated trophic position and carbon source for three consumers (Florida gar, Lepisosteus platyrhincus; eastern mosquitofish, Gambusia holbrooki; and riverine grass shrimp, Palaemonetes paludosus) from 20 sites representing gradients of productivity and hydrological disturbance in the southern Florida Everglades, U.S.A. We characterized gross primary productivity at each site using light/dark bottle incubation and stem density of emergent vascular plants. We also documented nutrient availability as total phosphorus (TP) in floc and periphyton, and the density of small fishes. Hydrological disturbance was characterized as the time since a site was last dried and the average number of days per year the sites were inundated for the previous 10 years. Food-web attributes were estimated in both the wet and dry seasons by analysis of δ15N (trophic position) and δ13C (food-web carbon source) from 702 samples of aquatic consumers. An index of carbon source was derived from a two-member mixing model with Seminole ramshorn snails (Planorbella duryi) as a basal grazing consumer and scuds (amphipods Hyallela azteca) as a basal detritivore. Snails yielded carbon isotopic values similar to green algae and diatoms, while carbon values of scuds were similar to bulk periphyton and floc; carbon isotopic values of cyanobacteria were enriched in C13compared to all consumers examined. A carbon source similar to scuds dominated at all but one study site, and though the relative contribution of scud-like and snail-like carbon sources was variable, there was no evidence that these contributions were a function of abiotic factors or season. Gar consistently displayed the highest estimated trophic position of the consumers studied, with mosquitofish feeding at a slightly lower level, and grass shrimp feeding at the lowest level. Trophic position was not correlated with any nutrient or productivity parameter, but did increase for grass shrimp and mosquitofish as the time following droughts increased. Trophic position of Florida gar was positively correlated with emergent plant stem density.

Productivity: A Review For The Hospitality Manager

Hospitality managers have a number of methods available to them to enhance employee productivity. The author discusses five major concepts that can lead to successful results in the hospitality industry.

Labor Cost Analysis for the Food Service Industry

There are many factors which can assist in controlling the cost of labor in the food service industry. The author discusses a number of these, including scheduling, establishing production standards, forecasting workloads, analyzing employee turnover, combating absenteeism, and controlling overtime.

Closing the productivity gap and trade *policy

The relationship between trade policy and productivity growth is regarded as ambiguous in the literature. This dissertation examines under what condition the relationship would be positive (or negative). Through the use of static and dynamic analysis, we find two conflicting effects (the pro-protection effect and the pro-competitive effect) that cause the relationship to be ambiguous. If there exists a productivity gap between the import-competing and foreign industries, and if the level of protection is low (high), the relationship is positive (negative). We also show that the import-competing firm responds to a change in the protection level by choosing a level of investment in innovation which yields a different rate of productivity growth. The policy implication, therefore, is that a trade-policy maker should set the trade protection at a level which induces the firm to choose the highest rate of productivity growth, and, as a result, leading the firm to close the initial productivity gap in the most efficient way. ^

AIDS workplace *policy adoption and implementation in local government: An analysis of departmental variation

This is an empirical study whose purpose was to examine the process of innovation adoption as an adaptive response by a public organization and its subunits existing under varying degrees of environmental uncertainty. Meshing organization innovation research and contingency theory to form a theoretical framework, an exploratory case study design was undertaken in a large, metropolitan government located in an area with the fourth highest prevalence rate of HIV/AIDS in the country. A number of environmental and organizational factors were examined for their influence upon decision making in the adoption/non-adoption as well as implementation of any number of AIDS-related policies, practices, and programs.^ The major findings of the study are as follows. For the county government itself (macro level), no AIDS-specific workplace policies have been adopted. AIDS activities (AIDS education, AIDS Task Force, AIDS Coordinator, etc.), adopted county-wide early in the epidemic, have all been abandoned. Worker infection rates, in the aggregate and throughout the epidemic have been small. As a result, absent co-worker conflict (isolated and negligible), no increase in employee health care costs, no litigation regarding discrimination, and no major impact on workforce productivity, AIDS has basically become a non-issue at the strategic core of the organization. At the departmental level, policy adoption decisions varied widely. Here the predominant issue is occupational risk, i.e., both objective as well as perceived. As expected, more AIDS-related activities (policies, practices, and programs) were found in departments with workers known to have significant risk for exposure to the AIDS virus (fire rescue, medical examiner, police, etc.). AIDS specific policies, in the form of OSHA's Bloodborn Pathogen Standard, took place primarily because they were legislatively mandated. Union participation varied widely, although not necessarily based upon worker risk. In several departments, the union was a primary factor bringing about adoption decisions. Additional factors were identified and included organizational presence of AIDS expertise, availability of slack resources, and the existence of a policy champion. Other variables, such as subunit size, centralization of decision making, and formalization were not consistent factors explaining adoption decisions. ^

Allocation of Biomass and Net Primary Productivity of Mangrove Forests along Environmental Gradients in the Florida Coastal Everglades, USA

Vegetation patterns of mangroves in the Florida Coastal Everglades (FCE) result from the interaction of environmental gradients and natural disturbances (i.e., hurricanes), creating an array of distinct riverine and scrub mangroves across the landscape. We investigated how landscape patterns of biomass and total net primary productivity (NPPT), including allocation in above- and below-ground mangrove components, vary inter-annually (2001–2004) across gradients in soil properties and hydroperiod in two distinct FCE basins: Shark River Estuary and Taylor River Slough. We propose that the allocation of belowground biomass and productivity (NPPB) relative to aboveground allocation is greater in regions with P limitation and permanent flooding. Porewater sulfide was significantly higher in Taylor River (1.2 ± 0.3 mM) compared to Shark River (0.1 ± 0.03 mM) indicating the lack of a tidal signature and more permanent flooding in this basin. There was a decrease in soil P density and corresponding increase in soil N:P from the mouth (28) to upstream locations (46–105) in Shark River that was consistent with previous results in this region. Taylor River sites showed the highest P limitation (soil N:P > 60). Average NPPT was double in higher P environments (17.0 ± 1.1 Mg ha−1 yr−1) compared to lower P regions (8.3 ± 0.3 Mg ha−1 yr−1). Root biomass to aboveground wood biomass (BGB:AWB) ratio was 17 times higher in P-limited environments demonstrating the allocation strategies of mangroves under resource limitation. Riverine mangroves allocated most of the NPPT to aboveground (69%) while scrub mangroves showed the highest allocation to belowground (58%). The total production to biomass (P:B) ratios were lower in Shark River sites (0.11 yr−1); whereas in Taylor River sites P:B ratios were higher and more variable (0.13–0.24 yr−1). Our results suggest that the interaction of lower P availability in Taylor River relative to Shark River basin, along with higher sulfide and permanent flooding account for higher allocation of belowground biomass and production, at expenses of aboveground growth and wood biomass. These distinct patterns of carbon partitioning between riverine and scrub mangroves in response to environmental stress support our hypothesis that belowground allocation is a significant contribution to soil carbon storage in forested wetlands across FCE, particularly in P-limited scrub mangroves. Elucidating these biomass strategies will improve analysis of carbon budgets (storage and production) in neotropical mangroves and understanding what conditions lead to net carbon sinks in the tropical coastal zone.