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2.
PLoS One ; 8(11): e79853, 2013.
Article in English | MEDLINE | ID: mdl-24265787

ABSTRACT

Pollinators serve critical roles for the functioning of terrestrial ecosystems, and have an estimated annual value of over $150 billion for global agriculture. Mounting evidence from agricultural systems reveals that pollinators are declining in many regions of the world, and with a lack of information on whether pollinator communities in natural systems are following similar trends, identifying factors which support pollinator visitation and services are important for ameliorating the effects of the current global pollinator crisis. We investigated how fire affects resource structure and how that variation influences floral pollinator communities by comparing burn versus control treatments in a southeastern USA old-field system. We hypothesized and found a positive relationship between fire and plant density of a native forb, Verbesina alternifolia, as well as a significant difference in floral visitation of V. alternifolia between burn and control treatments. V. alternifolia density was 44% greater and floral visitation was 54% greater in burned treatments relative to control sites. When the density of V. alternifolia was experimentally reduced in the burn sites to equivalent densities observed in control sites, floral visitation in burned sites declined to rates found in control sites. Our results indicate that plant density is a proximal mechanism by which an imposed fire regime can indirectly impact floral visitation, suggesting its usefulness as a tool for management of pollination services. Although concerns surround the negative impacts of management, indirect positive effects may provide an important direction to explore for managing future ecological and conservation issues. Studies examining the interaction among resource concentration, plant apparency, and how fire affects the evolutionary consequences of altered patterns of floral visitation are overdue.


Subject(s)
Ecosystem , Fires , Pollination , Agriculture , Plant Physiological Phenomena , Population Density
3.
Regen Med ; 4(1): 27-32, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19250058

ABSTRACT

During his campaign, US President-elect Obama pledged to use an executive order to overturn federal-funding limits on research into human embryos that are created during fertility treatments imposed by President Bush. Robert Klein, Chairman of the Governing Board of California's stem cell funding agency, Governor Jim Doyle, and Bernard Siegel, Executive Director of the Genetics Policy Institute, discuss the implications of the new administration for regenerative medicine research in the USA.


Subject(s)
Embryo Research/economics , Federal Government , Regenerative Medicine/economics , Embryo Research/legislation & jurisprudence , Financing, Government , Government Regulation , Humans , Regenerative Medicine/legislation & jurisprudence , United States
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