775 research outputs found
A Step towards Valuing Utility the Marginal and Cardinal Way
Income has a direct impact on our utility as well as an indirect impact through the goods, services and life events it allows us to purchase. The indirect effect of income is not properly accounted for in existing research that uses measures of cardinal utility for economic analysis. We propose a new approach for appropriately attributing the full effects of income on utility and we show the implications of our approach using a longitudinal dataset that contains reports of subjective wellbeing (SWB). We show that income has a much greater effect on SWB when indirect effects are considered. These results have important implications for how we value the marginal benefits of non-market goods and we explore some of these issues in the papersubjective well-being, utility, happiness, multicollinearity, income, non-market goods
Localized shear generates three-dimensional transport
Understanding the mechanisms that control three-dimensional (3D) fluid
transport is central to many processes including mixing, chemical reaction and
biological activity. Here a novel mechanism for 3D transport is uncovered where
fluid particles are kicked between streamlines near a localized shear, which
occurs in many flows and materials. This results in 3D transport similar to
Resonance Induced Dispersion (RID); however, this new mechanism is more rapid
and mutually incompatible with RID. We explore its governing impact with both
an abstract 2-action flow and a model fluid flow. We show that transitions from
one-dimensional (1D) to two-dimensional (2D) and 2D to 3D transport occur based
on the relative magnitudes of streamline jumps in two transverse directions.Comment: Copyright 2017 AIP Publishing. This article may be downloaded for
personal use only. Any other use requires prior permission of the author and
AIP Publishin
Linking vegetation change, carbon sequestration and biodiversity
1. Despite recent interest in linkages between above- and belowground communities and their consequences for ecosystem processes, much remains unknown about their responses to long-term ecosystem change. We synthesize multiple lines of evidence from a long-term ‘natural experiment’ to illustrate how ecosystem retrogression (the decline in ecosystem processes due to long-term absence of major disturbance) drives vegetation change, and thus aboveground and belowground carbon (C) sequestration, and communities of consumer biota.
2. Our study system involves 30 islands in Swedish boreal forest that form a 5000 year fire-driven retrogressive chronosequence. Here, retrogression leads to lower plant productivity and slower decomposition, and a community shift from plants with traits associated with resource acquisition to those linked with resource conservation.
3. We present consistent evidence that aboveground ecosystem C sequestration declines, while belowground and total C storage increases linearly for at least 5000 years following fire absence. This increase is driven primarily by changes in vegetation characteristics, impairment of decomposer organisms and absence of humus combustion.
4. Data from contrasting trophic groups show that during retrogression, biomass or abundance of plants and decomposer biota decreases, while that of aboveground invertebrates and birds increases, due to different organisms accessing resources via distinct energy channels. Meanwhile, diversity measures of vascular plants and aboveground (but not belowground) consumers respond positively to retrogression.
5. We show that taxonomic richness of plants and aboveground consumers are positively correlated with total ecosystem C storage, suggesting that conserving old growth forests simultaneously maximizes biodiversity and C sequestration. However, we find little observational or experimental evidence that plant diversity is a major driver of ecosystem C storage on the islands relative to other biotic and abiotic factors.
6. Synthesis. Our study reveals that across contrasting islands differing in exposure to a key extrinsic driver (historical disturbance regime and resulting retrogression), there are coordinated responses of soil fertility, vegetation, consumer communities, and ecosystem C sequestration, which all feed back to one another. It also highlights the value of well replicated natural experiments for tackling questions about aboveground-belowground linkages over temporal and spatial scales that are otherwise unachievable
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