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71.
The conservation of biodiversity is an important issue world wide and in Australia the maintenance of native biodiversity on farms makes an important contribution to overall conservation objectives. This paper seeks to explain Australian farmers' rationale for maintaining biodiversity on their farms for personal as opposed to business reasons by developing a decision-systems theory from in-depth interviews. This difference has implications for policy development. The decision-systems theory is divided into two main sections. The first section contains five parts. (1) A hierarchy of motivation stories, (2) the concept of suitability and availability of opportunities, (3) a hierarchy of three decision-systems, (4) the concept of personal career paths, (5) the concept of Lenses. The second section contains one part, a policy classification system called 'boxes of influence' that suggests how policy developers can use the information in the first section to develop new biodiversity conservation policy. The paper suggests that decision-systems theory could be used to shed new light on current trends in agriculture and become an important investigative tool for policy development concerning the conservation of biodiversity on farms. 相似文献
72.
The concentration of dissolved reactive phosphorus (DRP) in rivers can change intermittently within minutes depending on the weather and water discharge (Q), or activities in the watershed. Accordingly, accurate estimation of the annual DRP load requires frequent sampling or even continuous monitoring, which is laborious and cost-intensive. We present the design and laboratory evaluation of a new, robust, low-cost, low-tech device based on passive samplers (P-traps). The traps use Fe-(oxy)hydroxide coated quartz sand as an adsorbent enclosed in a vertical grid of individual cells separated from the river water by filter membranes. They are inexpensive, easy to handle, resistant to repeated desiccation and immersion and exposable for several months. They permit estimation of discharge dependent time weighted average DRP concentrations (C-Q relationships) and annual P loads of rivers characterized by highly variable DRP concentrations with a relative accuracy of +/- 3%. 相似文献
73.
India’s continued development depends on the availability of adequate water. This paper applies a data-driven approach to estimate the intra-annual dynamics of water stress across the central Indian Highlands over the period 2002–2012. We investigate the spatial distribution of water demanding sectors including industry, domestic, irrigation, livestock and thermal power generation. We also examine the vulnerability of urban centers within the study area to water stress. We find that 74 % of the area of the central Indian Highlands experienced water stress (defined as demand exceeding supply) for 4 or more months out of the year. The rabi (winter) season irrigation drives the intra-annual water stress across the landscape. The Godavari basin experiences the most surface water stress while the Ganga and Narmada basins experience water stress due to groundwater deficits as a result of rabi irrigation. All urban centers experience water stress at some time during a year. Urban centers in the Godavari basin are considerably water stressed, for example, Achalpur, Nagpur and Chandrapur experience water stress 8 months out of the year. Irrigation dominates water use accounting for 95 % of the total water demand, with substantial increases in irrigated land over the last decade. Managing land use to promote hydrologic functions will become increasingly important as water stress increases. 相似文献
74.
This paper develops and tests hypotheses concerning some psychological correlates of role ambiguity and role conflict in a population that has not been extensively studied in relation to stress, union stewards. Survey data on role ambiguity and role conflict, the indicators of stress, were collected from 285 stewards at the local union steward meeting, with the stewards perceiving a moderate amount of role ambiguity and perceiving a lesser amount of role conflict. The stewards were also asked about their role expectations, their motivations for remaining a steward, their grievance handling strategies, and their affective commitment toward the union and employer. Each of those four sets of variables was hypothesized to be related to role ambiguity and role conflict and each was influential in explaining variance. As predicted, those stewards who were more motivated to remain stewards for personal reasons had both higher role ambiguity and higher role conflict. Further, the conditions of being more motivated to remain a steward to help the union and employees and having higher union commitment were associated with lower role conflict, but, opposite to the hypotheses, higher role ambiguity. 相似文献
75.
Christopher J. Richards Honesto Roaza Ruth Montgomery Roaza 《Journal of the American Water Resources Association》1993,29(5):847-853
ABSTRACT: The Floridan Aquifer is the primary source of water in the coastal area of Santa Rosa County, Florida. In order to optimize well field design and analyze aquifer stress problems, the USGS MODFLOW code (McDonald and Harbaugh, 1988) is applied to develop a numerical computer model of the aquifer. The Geographical Information System (GIS) is the primary tool used in the development of the model grid, performance of the modeling procedure, and model analysis. The GIS is used in generating multiple grids in which to simulate both regional scale and local scale flow. The grid topology is recorded in geographic coordinates which facilitates geo-referencing and orientation of the grid to base maps and data coyerages. The GIS allows data transfer from various coverages to the nodes of the block centered grid where hydrogeologic information is stored as attributes to the grid coverage. From this grid coverage, pertinent information is queried within the GIS environment and used to generate the input files for the MODFLOW simulation. After MODFLOW execution, simulated heads and drawdown are imported into the grid coverage where residual error and recharge rates can be calculated. Contoured surfaces are then created for selected data sets including simulated heads, drawdown, residual error, and recharge rates. Model calibration is conducted utilizing the GIS to generate and process data sets associated with model simulations. 相似文献
76.
Investigations using chlorophyll fluorescence induction kinetics provide the parameters Rfd, L, and Ap to characterize different specifications of the photosynthetic system (PS). The application of ozone, with concentrations between 100 microg m(-3) and 2000 microg m(-3) to spruce in closed chambers yields a reduction of Rfd between 6% and 23% for the current year's needles, which indicates a reduced potential photosynthetic capacity. Further measurements on the current year's needles of spruce of the damage classes S0/S1, S2 and S3 show also a reduction of Rfd of between 7% and 14% in 2 successive years. In addition, the parameter L increases for damaged trees by between 11% and 49%, indicating a change of the chlorophyll content and of the internal energy distribution between PSI and PSII. As no effect of L can be observed with ozone fumigation, it is concluded that the change of some specifications of the PS can be simulated well by ozone fumigation (e.g. Rfd) while other specifications cannot (e.g. L). 相似文献
77.
Sibyl Anwander Phan-Huy Ruth Badertscher Fawaz 《Journal of Agricultural and Environmental Ethics》2003,16(2):119-136
Animal welfare is an importantsocietal issue in Switzerland. Policy makershave responded with a strict legislation onanimal protection and with two programs topromote animal friendly husbandry. Alsoprivate actors in the meat industry initiatedprograms for animal friendly meat productionto meet consumers' expectations. Labeled meathas a market share of over 20%. Depending onthe stakeholders responsible for the labels,their objectives vary. While retailers want toattract consumers with meat produced in ananimal friendly and environmentally compatiblemanner and with products of consistently goodsensory quality, producers want to keep marketshares and increase their revenues. 相似文献
78.
Ruth Offermann Thilo Seidenberger Daniela Thrän Martin Kaltschmitt Sergey Zinoviev Stanislav Miertus 《Mitigation and Adaptation Strategies for Global Change》2011,16(1):103-115
So far, various studies assessed global biomass potentials and came up with widely varying results. Existing potential estimates
range from 0 EJ/a up to more than 1,550 EJ/a which corresponds to about three times the current global primary energy consumption.
This paper provides an overview of the available research on bioenergy potentials and reviews the different assessments qualitative
way with the objective to interpret previous research in an integrated way. In the context of this paper we understand bioenergy
as energy from biomass sources including energy crops, residues, byproducts and wastes from agriculture, forestry, food production
and waste management. In this review special attention was paid to the difference between residue and energy potentials, land
availability estimates, and the geographical resolution of existing potential estimates. The majority of studies concentrate
on energy crop potentials retrieved from surplus agricultural land and only few publications assess global potentials separated
by different world regions. It results that land allocated to the exclusive production of energy crops varies from 0 to 7,000 ha,
depending on land category and scenario assumptions. Only a small number of available potential assessments consider residue
potentials as well as energy crop potentials from degraded land. Future energy crop potentials are assumed to vary in the
mean from 200 to 600 EJ/yr. In contrast residue potentials are expected to contribute between 62 and 325 EJ/yr. The highest
potentials are assigned to Asia, Africa and South America while Europe, North America and the Pacific region contribute minor
parts to the global potential. 相似文献
79.
Lirman D Gracias NR Gintert BE Gleason AC Reid RP Negahdaripour S Kramer P 《Environmental monitoring and assessment》2007,125(1-3):59-73
The recent decline in the condition of coral reef communities worldwide has fueled the need to develop innovative assessment
tools to document coral abundance and distribution rapidly and effectively. While most monitoring programs rely primarily
on data collected in situ by trained divers, digital photographs and video are used increasingly to extract ecological indicators, provide a permanent
visual record of reef condition, and reduce the time that divers spend underwater. In this study, we describe the development
and application of a video-based reef survey methodology based on an algorithm for image registration and the estimation of
image motion and camera trajectory. This technology was used to construct two-dimensional, spatially accurate, high-resolution
mosaics of the reef benthos at a scale of up to 400 m2. The mosaics were analyzed to estimate the size and percent cover of reef organisms and these ecological indicators of reef
condition were compared to similar measurements collected by divers to evaluate the potential of the mosaics as monitoring
tools. The ecological indicators collected by trained divers compared favorably with those measured directly from the video
mosaics. Five out of the eight categories chosen (hard corals, octocorals, Palythoa, algal turf, and sand) showed no significant differences in percent cover based on survey method. Moreover, no significant
differences based on survey method were found in the size of coral colonies. Lastly, the capability to extract the same reef
location from mosaics collected at different times proved to be an important tool for documenting change in coral abundance
as the removal of even small colonies (<10 cm in diameter) was easily documented. The two-dimensional video mosaics constructed
in this study can provide repeatable, accurate measurements on the reef-plot scale that can complement measurements on the
colony-scale made by divers and surveys conducted at regional scales using remote sensing tools. 相似文献
80.
Maie Bachmann Ruth Tomson Jaan Kalda Maksim Säkki Jaanus Lass Viiu Tuulik Hiie Hinrikus 《The Environmentalist》2007,27(4):511-517
This study was aimed to investigate the changes in the human electroencephalographic (EEG) signal caused by modulated low-level
microwaves. The 450 MHz microwave exposure modulated at 40 Hz and 70 Hz frequencies was applied to a group of 15 volunteers.
The field power density at the scalp was 0.16 mW/cm2. Ten cycles of the exposure (1 min on and 1 min off) at both modulation frequencies were applied. Analysis of the EEG signal
was performed using three different methods: nonlinear method of scaling analysis for length distribution of low variability
periods (LDLVP), relative changes in EEG energy (S-parameter) and beta ratio (H-parameter). The analysis revealed significant changes caused by microwave for the whole group (H-parameter method). The exposure caused increase of the EEG beta power (S-parameter method). Statistically significant changes in EEG were detected for four subjects (26.7%) at 40 Hz modulation frequency
(LDLVP method). 相似文献