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991.
Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands 总被引:2,自引:1,他引:1
Troy AR Grove JM O'Neil-Dunne JP Pickett ST Cadenasso ML 《Environmental management》2007,40(3):394-412
This paper examines predictors of vegetative cover on private lands in Baltimore, Maryland. Using high-resolution spatial
data, we generated two measures: “possible stewardship,” which is the proportion of private land that does not have built
structures on it and hence has the possibility of supporting vegetation, and “realized stewardship,” which is the proportion
of possible stewardship land upon which vegetation is growing. These measures were calculated at the parcel level and averaged
by US Census block group. Realized stewardship was further defined by proportion of tree canopy and grass. Expenditures on
yard supplies and services, available by block group, were used to help understand where vegetation condition appears to be
the result of current activity, past legacies, or abandonment. PRIZM™ market segmentation data were tested as categorical
predictors of possible and realized stewardship and yard expenditures. PRIZM™ segmentations are hierarchically clustered into
5, 15, and 62 categories, which correspond to population density, social stratification (income and education), and lifestyle
clusters, respectively. We found that PRIZM 15 best predicted variation in possible stewardship and PRIZM 62 best predicted
variation in realized stewardship. These results were further analyzed by regressing each dependent variable against a set
of continuous variables reflective of each of the three PRIZM groupings. Housing age, vacancy, and population density were
found to be critical determinants of both stewardship metrics. A number of lifestyle factors, such as average family size,
marriage rates, and percentage of single-family detached homes, were strongly related to realized stewardship. The percentage
of African Americans by block group was positively related to realized stewardship but negatively related to yard expenditures. 相似文献
992.
Ferreira Leide Lene C. Abreu Marina P. Costa Camila B. Leda Paulo O. Behrens Maria Dutra dos Santos Elisabete Pereira 《Food and environmental virology》2022,14(2):120-137
Food and Environmental Virology - The use of natural resources for the prevention and treatment of diseases considered fatal to humanity has evolved. Several medicinal plants have nutritional and... 相似文献
993.
Location and migration of cations in Cu(2+)-adsorbed montmorillonite 总被引:10,自引:0,他引:10
Locations of Cu2+ ion in Cu(2+)-adsorbed montmorillonite have been studied by electron paramagnetic resonance (EPR), supplemented by X-ray diffraction (XRD) and differential thermal analysis (DTA). In the EPR spectra of Cu(2+)-adsorbed montmorillonite, three signals, corresponding to Cu2+ ion, have been simultaneously recorded. Some Cu2+ ions seemed to replace the original interlayer metal cations and some entered into the hexagonal cavities. A small fraction of Cu2+ ions penetrated into the octahedral vacancies. There were two ways for the adsorption of Cu2+ ion by montmorillonite--exchangeable and specific. On heating, the hydrated Cu2+ ion in the interlayer loses the coordinating water and then enters into the hexagonal cavities. When the heating temperature further increased, dehydroxylation occurs, which facilitates Cu2+ ion in the hexagonal cavities to penetrate into the octahedral vacancies. 相似文献
994.
Pöllänen R Ikäheimonen TK Klemola S Vartti VP Vesterbacka K Ristonmaa S Honkamaa T Sipilä P Jokelainen I Kosunen A Zilliacus R Kettunen M Hokkanen M 《Journal of environmental radioactivity》2003,64(2-3):133-142
Projectiles suspected to be composed of depleted uranium (DU) were found in Kosovo. Their properties were analysed using alpha and gamma ray spectrometry, mass spectrometry and electron microscopy. They were found to be composed of DU with small amounts of other elements such as Ti. 236U was detected in the penetrators, reflecting the use of reprocessed fuel. No transuranium elements were detected. The typical external dose rate meter is not the best option for mapping the location of penetrators from the ground. Monte Carlo calculations were performed in estimating possible skin doses. Penetrators in long-lasting contact with skin may cause a notable equivalent dose to skin. 相似文献
995.
Atmospheric xenon radioactive isotope monitoring 总被引:2,自引:0,他引:2
Fontaine JP Pointurier F Blanchard X Taffary T 《Journal of environmental radioactivity》2004,72(1-2):129-135
The Comprehensive Nuclear Test Ban Treaty (CTBT) organisation is implementing a world-wide monitoring network in order to check that the State Signatories comply with the treaty. One of the monitoring facilities consists of an atmospheric noble gas monitoring equipment. According to the requirements annexed in the treaty, the French Atomic Energy Commission (CEA) developed a device, called SPALAX, which automatically extracts xenon from ambient air and makes in situ measurements of the activities of four xenon radioisotopes (131mXe, 133mXe, 133Xe, 135Xe). The originality of this device is noticeable essentially in the gas sample processing method: thanks to the coupling of a gas permeator and of a noble gas specific adsorbent, it can selectively extract and concentrate xenon to more than 3 x 10 E6. This process is carried out continuously without cryogenic cooling, without any regeneration time. The detection of the xenon radioactive isotopes is done automatically by high spectral resolution gamma spectrometry, a robust technology well-suited for on-field instrumentation. In the year 2000, a prototype was involved in an international evaluation exercise directed by the CTBT organisation (CTBTO). This exercise demonstrated that the SPALAX equipment perfectly met the requirements of the CTBTO for such systems. On the basis of the continuous 24-h resolution record of the atmospheric xenon radioactive isotopes concentrations, the SPALAX system also demonstrated that ambient levels of 133Xe can fluctuate quickly from less than the detection limit to over 40 x 10(-3) Bq m(-3). In order to build an industrial version of this equipment, the CEA entered into a partnership with a French engineering company (S.F.I., Marseille, France), which is now able to produce an industrial version of SPALAX, i.e. more compact and more efficient than the prototypes. The 133Xe minimum detectable concentration is 0.15 x 10(-3) Bq m(-3) air per 24 h sampling cycle. 相似文献
996.
Jeffrey D. Fore Scott P. Sowa David L. Galat Gust M. Annis David D. Diamond Charles Rewa 《Environmental management》2014,53(3):567-582
Managers can improve conservation of lotic systems over large geographies if they have tools to assess total watershed conditions for individual stream segments and can identify segments where conservation practices are most likely to be successful (i.e., primary management capacity). The goal of this research was to develop a suite of threat indices to help agriculture resource management agencies select and prioritize watersheds across Missouri River basin in which to implement agriculture conservation practices. We quantified watershed percentages or densities of 17 threat metrics that represent major sources of ecological stress to stream communities into five threat indices: agriculture, urban, point-source pollution, infrastructure, and all non-agriculture threats. We identified stream segments where agriculture management agencies had primary management capacity. Agriculture watershed condition differed by ecoregion and considerable local variation was observed among stream segments in ecoregions of high agriculture threats. Stream segments with high non-agriculture threats were most concentrated near urban areas, but showed high local variability. 60 % of stream segments in the basin were classified as under U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) primary management capacity and most segments were in regions of high agricultural threats. NRCS primary management capacity was locally variable which highlights the importance of assessing total watershed condition for multiple threats. Our threat indices can be used by agriculture resource management agencies to prioritize conservation actions and investments based on: (a) relative severity of all threats, (b) relative severity of agricultural threats, and (c) and degree of primary management capacity. 相似文献
997.
Restoring prairie on formerly cultivated land begins by selecting propagule seed sources and the diversity of species to reintroduce. This study examined the effects of dominant grass propagule source (cultivar vs. non-cultivar) and sown propagule diversity (grass:forb sowing ratio) on plant community structure. Two field experiments were established in Kansas and Illinois consisting of identical split plot designs. Dominant grass source was assigned as the whole-plot factor, and sown dominance of grasses (five levels of seeded grass dominance) as the subplot factor. Species density, cover, and diversity were quantified for 5 years. The effect of dominant grass source on the cover of focal grasses, sown species, and volunteer species was contingent upon location, with variation between dominant grass sources observed exclusively in Kansas. Species density and diversity showed regionally convergent patterns in response to dominant grass source. Contrary to our hypotheses, total species density and diversity were not lower in the presence of grass cultivars, the grass source we had predicted would be more competitive. Sown grass dominance effects on the cover of the focal grass species were contingent upon location resulting from establishment corresponding better to the assigned treatments in Illinois. All other cover groups showed regionally convergent patterns, with lower cover of volunteers and higher cover of sown forbs, diversity, and species density in the lowest sown grass dominance treatment in both sites. Thus, decisions regarding the diversity of propagules to reintroduce had more consequence for plant community structure than cultivar or non-cultivar source of dominant grasses. 相似文献
998.
There is evidence of a looming groundwater crisis in India. Unlike in the case of surface water, competition around groundwater generally does not result in open conflicts. Measurability and visibility of surface water accord a clearer public perception of water quantities, which leads to conflicts. Groundwater in an aquifer is sourced in a dispersed manner, and boundaries, quantities and interdependencies are less visible or measurable. Hence, groundwater resources go through intense and intricate competition between users and uses before open conflicts begin. Competition occurs with reference to sources rather than around the resource. The interdependency of sources is a function of changing patterns of usage as intricacies of aquifer characteristics come into play. Governance institutions and regulatory frameworks of groundwater need to be sensitive to the various forms in which groundwater competition manifests in different hydrogeological settings, and the consequences of this in terms of access and rights, in relation to issues of equity and justice. 相似文献
999.
Managing land sustainably is a huge challenge, especially under harsh climatic conditions such as those found in drylands. The socio-economic situation can also pose challenges, as dryland regions are often characterized by remoteness, marginality, low-productive farming, weak institutions, and even conflict. With threats from climate change, disputes over water, competing claims on land, and migration increasing worldwide, the demands for sustainable land management (SLM) measures will only increase in the future. Within the EU-funded DESIRE project, researchers and stakeholders jointly identified existing SLM technologies and approaches in 17 dryland study sites located in the Mediterranean and around the world. In order to evaluate and share this valuable SLM experience, local researchers documented the SLM technologies and approaches in collaboration with land users, utilizing the internationally recognized WOCAT questionnaires. This article provides an analysis of 30 technologies and 8 approaches, enabling an initial evaluation of how SLM addresses prevalent dryland threats, such as water scarcity, soil degradation, vegetation degradation and low production, climate change, resource use conflicts, and migration. Among the impacts attributed to the documented technologies, those mentioned most were diversified and enhanced production and better management of water and soil degradation, whether through water harvesting, improving soil moisture, or reducing runoff. Favorable local-scale cost–benefit relationships were mainly found when considered over the long term. Nevertheless, SLM was found to improve people’s livelihoods and prevent further outmigration. More field research is needed to reinforce expert assessments of SLM impacts and provide the necessary evidence-based rationale for investing in SLM. 相似文献
1000.
Sven Rannow Nicholas A. Macgregor Juliane Albrecht Humphrey Q. P. Crick Michael Förster Stefan Heiland Georg Janauer Mike D. Morecroft Marco Neubert Anca Sarbu Jadwiga Sienkiewicz 《Environmental management》2014,54(4):732-743
The implementation of adaptation actions in local conservation management is a new and complex task with multiple facets, influenced by factors differing from site to site. A transdisciplinary perspective is therefore required to identify and implement effective solutions. To address this, the International Conference on Managing Protected Areas under Climate Change brought together international scientists, conservation managers, and decision-makers to discuss current experiences with local adaptation of conservation management. This paper summarizes the main issues for implementing adaptation that emerged from the conference. These include a series of conclusions and recommendations on monitoring, sensitivity assessment, current and future management practices, and legal and policy aspects. A range of spatial and temporal scales must be considered in the implementation of climate-adapted management. The adaptation process must be area-specific and consider the ecosystem and the social and economic conditions within and beyond protected area boundaries. However, a strategic overview is also needed: management at each site should be informed by conservation priorities and likely impacts of climate change at regional or even wider scales. Acting across these levels will be a long and continuous process, requiring coordination with actors outside the “traditional” conservation sector. To achieve this, a range of research, communication, and policy/legal actions is required. We identify a series of important actions that need to be taken at different scales to enable managers of protected sites to adapt successfully to a changing climate. 相似文献