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51.
Livelihood diversification is essential to food security and improved incomes for human development in African rural communities. Uganda's agrarian economy suffers from limited diversification, environmental degradation, low incomes, and multifaceted negative impacts of AIDS. Efforts to stimulate and support innovation in agricultural production technology, forms of social organization, and poor markets are essential elements in promotion of sustainable rural livelihoods. Iowa State University's Center for Sustainable Rural Livelihoods and its partner organizations are applying a multi-dimensional approach to engage Uganda farmers and rural leaders in community-based learning and capability strengthening. We describe the role played by livelihood diversification and explore the promotion of sustainable livelihoods through scholarship with praxis. Sustainable livelihoods concepts are examined as a means to better understand contemporary African rural development. We identify principles and processes critical to achieving sustainable livelihoods. Their application is highlighted based on our early collaborative experience, including a discussion of the complexities associated with entering into balanced partnerships required for a successful community-based program. We explore the value of social science perspectives and processes for strengthening rural development in developing countries. 相似文献
52.
Gavin McDonald Molly Wilson Diogo Veríssimo Rebecca Twohey Michaela Clemence Dean Apistar Stephen Box Paul Butler Fel Cesar Cadiz Stuart J. Campbell Courtney Cox Micah Effron Steve Gaines Raymond Jakub Roquelito H. Mancao Pablo T. Rojas Rocky Sanchez Tirona Gabriel Vianna 《Conservation biology》2020,34(5):1176-1189
Small-scale fisheries are an important livelihood and primary protein source for coastal communities in many of the poorest regions in the world, yet many are overfished and thus require effective and scalable management solutions. Positive ecological and socioeconomic responses to management typically lag behind immediate costs borne by fishers from fishing pressure reductions necessary for fisheries recovery. These short-term costs challenge the long-term success of these interventions. However, social marketing may increase perceptions of management benefits before ecological and socioeconomic benefits are fully realized, driving new social norms and ultimately long-term sustainable behavior change. By conducting underwater visual surveys to quantify ecological conditions and by conducting household surveys with community members to quantify their perceptions of management support and socioeconomic conditions, we assessed the impact of a standardized small-scale fisheries management intervention that was implemented across 41 sites in Brazil, Indonesia, and the Philippines. The intervention combines TURF reserves (community-based territorial use rights for fishing coupled with no-take marine reserves) with locally tailored social-marketing behavior change campaigns. Leveraging data across 22 indicators and 4 survey types, along with data from 3 control sites, we found that ecological and socioeconomic impacts varied and that communities supported the intervention and were already changing their fishing practices. These results suggest that communities were developing new social norms and fishing more sustainably before long-term ecological and socioeconomic benefits of fisheries management materialized. 相似文献
53.
This study utilizes remote sensing derived forest aboveground biomass (AGB) estimates and ownership information obtained from
the Protected Areas Database (PAD), combining landscape analyses and GIS techniques to demonstrate how different ownerships
(public, regulated private, and other private) relate to the spatial distribution of AGB in New England states of the USA.
“Regulated private” lands were dominated by lands in Maine covered by a Land Use Regulatory Commission. The AGB means between
all pairs of the identified ownership categories were significantly different (P < 0.05). Mean AGB observed in public lands (156 Mg/ha) was 43% higher than that in regulated private lands (109 Mg/ha), or
30% higher than that of private lands as a whole. Seventy-seven percent of the regional forests (or about 9,300 km2) with AGB >200 Mg/ha were located outside the area designated in the PAD and concentrated in western MA, southern VT, southwestern
NH, and northwestern CT. While relatively unfragmented and high-AGB forests (>200 Mg/ha) accounted for about 8% of total forested
land, they were unevenly proportioned among the three major ownership groups across the region: 19.6% of the public land,
0.8% of the regulated private land, and 11.0% of the other private land. Mean disturbance rates (in absolute value) between
1992 and 2001 were 16, 66, and 19 percent, respectively, on public, regulated private, and other private land. This indicates
that management practices from different ownerships have a strong impact on dynamic changes of landscape structures and AGB
distributions. Our results may provide insight information for policy makers on issues regarding forest carbon management,
conservation biology, and biodiversity studies at regional level. 相似文献
54.
Dylan Crouch Jay D. White Belinda Butler‐Veytia Robert Medler 《补救:环境净化治理成本、技术与工艺杂志》2010,21(1):137-151
Groundwater investigations conducted since 1988 at a Tennessee Department of Environment and Conservation (TDEC) Voluntary Oversight and Assistance Program (VOAP) site located in Millington, Tennessee, have defined the lateral and vertical extent of site chemicals of concern (COCs) consisting of tetrachloroethene (PCE), trichloroethene (TCE), and associated degradation products. Results of a groundwater remedial investigation determined that aquifer conditions were favorable for anaerobic degradation of COCs through reductive dechlorination. A subsequent groundwater feasibility study determined that monitored natural attenuation (MNA) coupled with long‐term groundwater monitoring was the most effective and suitable remedial option for the site. A Record of Decision was issued by the TDEC VOAP approving MNA and long‐term groundwater monitoring as the remedial option for the site, a first for such a site in Tennessee involving chlorinated organics. A groundwater fate and transport model (the 1998 model) developed during the RI was used as the basis for the MNA remedy. Analytical data from 1998 to 2008 indicate COCs in former high‐concentration areas continue to degrade at rates consistent with or ahead of the 1998 model predictions. Evidence of reductive dechlorination is also supported by the continued presence of breakdown products—specifically, vinyl chloride and ethene (terminal endpoint of PCE breakdown through reductive dechlorination). The continued detection of breakdown products along the flow‐path wells also confirms the effectiveness of the MNA remedy at the site. Current analytical data indicate that COC plumes beneath the site are not migrating and are actually retracting. © 2010 Wiley Periodicals, Inc. 相似文献
55.
Laboratory experiments assessed how bioaccumulation of weathered p,p′-DDE from soil and humic acid (HA) chemistry are affected by interactions between the plants Cucurbita pepo ssp. pepo and ssp. ovifera and the earthworms Eisenia fetida, Lumbricus terrestris, and Apporectodea caliginosa. Total organochlorine phytoextraction by ssp. pepo increased at least 25% in the presence of any of the earthworm species (relative to plants grown in isolation). Uptake of the compound by ssp. ovifera was unaffected by earthworms. Plants influenced earthworm bioaccumulation as well. When combined with pepo, p,p′-DDE levels in E. fetida decreased by 50%, whereas, in the presence of ovifera, bioconcentration by L. terrestris increased by more than 2-fold. Spectral analysis indicated a decrease in hydrophobicity of HA in each of the soils in which both pepo and earthworms were present. However, HA chemistry from ovifera treatments was largely unaffected by earthworms. Risk assessments of contaminated soils should account for species interactions, and SOM chemistry may be a useful indictor of pollutant bioaccumulation. 相似文献
56.
Callaghan TV Tweedie CE Akerman J Andrews C Bergstedt J Butler MG Christensen TR Cooley D Dahlberg U Danby RK Daniëls FJ de Molenaar JG Dick J Mortensen CE Ebert-May D Emanuelsson U Eriksson H Hedenås H Henry H R G Hik DS Hobbie JE Jantze EJ Jaspers C Johansson C Johansson M Johnson DR Johnstone JF Jonasson C Kennedy C Kenney AJ Keuper F Koh S Krebs CJ Lantuit H Lara MJ Lin D Lougheed VL Madsen J Matveyeva N Mcewen DC Myers-Smith IH Narozhniy YK Olsson H Pohjola VA Price LW Rigét F Rundqvist S 《Ambio》2011,40(6):705-716
Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in subarctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies. 相似文献
57.
Alleta P.S. Terblanche Halûk Özkaynak John D. Spengler David A. Butler 《Journal of the Air & Waste Management Association (1995)》2013,63(7):942-946
A study was designed to explore the relationship between self-reported activity levels and actual heart rate (HR) as measured by a portable heart rate monitor (Sport Tester PE3000). Twenty-two teenagers (8 boys, 14 girls, median age of 16) from Watertown High School, Massachusetts participated in this pilot study which involved continuous monitoring of HR during normal daily activities and simultaneous completion of a time/activity diary. There were 31 successful monitoring sessions ranging from 1.9 to 17 hours with a median monitoring time of 12.6 hours. Four unsuccessful monitoring sessions were experienced due to equipment failure. Apart from participant cooperation, the single most important factor affecting the feasibility of continuous heart rate monitoring was found to be equipment design. The overall average heart rate observed was 88.4 bpm (SD = 24.3). An individual’s correlation coefficient for perceived activity level (documented in half-hour intervals) and heart rate (averaged over the half-hour intervals) varied from 0.24 to 0.89. More than half of the correlation coefficients were below 0.40. There was a significant difference (P < .0001) between average heart rate for time spent indoors (90 bpm) versus outdoors (103 bpm) even after correcting for sleeping time. It is concluded that continuous HR monitoring with simultaneous completion of a time/activity diary is feasible and is a promising source of information for studies on exposure to air pollutants. 相似文献
58.
59.
Projecting Large-Scale Area Changes in Land Use and Land Cover for Terrestrial Carbon Analyses 总被引:1,自引:0,他引:1
One of the largest changes in US forest type areas over the last half-century has involved pine types in the South. The area of planted pine has increased more than 10-fold since 1950, mostly on private lands. Private landowners have responded to market incentives and government programs, including subsidized afforestation on marginal agricultural land. Timber harvest is a crucial disturbance affecting planted pine area, as other forest types are converted to planted pine after harvest. Conversely, however, many harvested pine plantations revert to other forest types, mainly due to passive regeneration behavior on nonindustrial private timberlands. We model land use and land cover changes as a basis for projecting future changes in planted pine area, to aid policy analysts concerned with mitigation activities for global climate change. Projections are prepared in two stages. Projected land use changes include deforestation due to pressures to develop rural land as the human population expands, which is a larger area than that converted from other rural lands (e.g., agriculture) to forestry. In the second stage, transitions among forest types are projected on land allocated to forestry. We consider reforestation, influences of timber harvest, and natural succession and disturbance processes. Baseline projections indicate a net increase of about 5.6 million ha in planted pine area in the South over the next 50 years, with a notable increase in sequestered carbon. Additional opportunities to expand pine plantation area warrant study of landowner behavior to aid in designing more effective incentives for inducing land use and land cover changes to help mitigate climate change and attain other goals. 相似文献
60.
Stochastic modelling of landfill processes incorporating waste heterogeneity and data uncertainty 总被引:2,自引:0,他引:2
A landfill is a very complex heterogeneous environment and as such it presents many modelling challenges. Attempts to develop models that reproduce these complexities generally involve the use of large numbers of spatially dependent parameters that cannot be properly characterised in the face of data uncertainty. An alternative method is presented, which couples a simplified microbial degradation model with a stochastic hydrological and contaminant transport model. This provides a framework for incorporating the complex effects of spatial heterogeneity within the landfill in a simplified manner, along with other key variables. A methodology for handling data uncertainty is also integrated into the model structure. Illustrative examples of the model's output are presented to demonstrate effects of data uncertainty on leachate composition and gas volume prediction. 相似文献