Impact of Permafrost Thaw and Climate Warming on Riverine Export Fluxes of Carbon, Nutrients and Metals in Western Siberia

The assessment of riverine fluxes of carbon, nutrients, and metals in surface waters of permafrost-affected regions is crucially important for constraining adequate models of ecosystem functioning under various climate change scenarios. In this regard, the largest permafrost peatland territory on the Earth, the Western Siberian Lowland (WSL) presents a unique opportunity of studying possible future changes in biogeochemical cycles because it lies within a south–north gradient of climate, vegetation, and permafrost that ranges from the permafrost-free boreal to the Arctic tundra with continuous permafrost at otherwise similar relief and bedrocks. By applying a “substituting space for time” scenario, the WSL south-north gradient may serve as a model for future changes due to permafrost boundary shift and climate warming. Here we measured export fluxes (yields) of dissolved organic carbon (DOC), major cations, macro- and micro- nutrients, and trace elements in 32 rivers, draining the WSL across a latitudinal transect from the permafrost-free to the continuous permafrost zone. We aimed at quantifying the impact of climate warming (water temperature rise and permafrost boundary shift) on DOC, nutrient and metal in rivers using a “substituting space for time” approach. We demonstrate that, contrary to common expectations, the climate warming and permafrost thaw in the WSL will likely decrease the riverine export of organic C and many elements. Based on the latitudinal pattern of riverine export, in the case of a northward shift in the permafrost zones, the DOC, P, N, Si, Fe, divalent heavy metals, trivalent and tetravalent hydrolysates are likely to decrease the yields by a factor of 2–5. The DIC, Ca, SO4, Sr, Ba, Mo, and U are likely to increase their yields by a factor of 2–3. Moreover, B, Li, K, Rb, Cs, N-NO3, Mg, Zn, As, Sb, Rb, and Cs may be weakly affected by the permafrost boundary migration (change of yield by a factor of 1.5 to 2.0). We conclude that modeling of C and element cycle in the Arctic and subarctic should be region-specific and that neglecting huge areas of permafrost peatlands might produce sizeable bias in our predictions of climate change impact.

What a highly controversial ethnography says about tensions, problematizations and inequality in contemporary ethnographic practice and regulation

Purpose The purpose of this paper is to illuminate how inequality – in the way ethnography as a research tool itself is used – underwrites many of the methodological tensions in the recently published and widely-debated On the Run: Fugitive Life in an American City by Alice Goffman. Design/methodology/approach The author conducts an in-depth, critical analysis of On the Run as an epistemological case to visualize methodological and moral challenges that burden ethnographic practice at large. Findings The author opens dialogue on undercover ethnography, the overreach of institutional review boards, privilege in the use of ethnography as a research tool, “Othering” and the exoticization of the underclass, and the boundary shift from observer to participant roles with deep immersion. The author unpacks these areas of contention toward the construction of a potential alternative combining public sociology with what is called a sociology of compassion. Originality/value While the book provides an intimate, rich account of the experience of law among the underclass, the author demonstrates that it constitutes an epistemological case ideal for examining how the issues of pre-fieldwork preparation, positionality and deep immersion are conceived – and problematized – in mainstream ethnographic practice.

Optimal Form for Compliance of Membrane Boundary Shift in Nonlinear Case

In this work, we search the existence shifting compliance optimal form of some boundary membrane, which is not elastic and not isotropic, generating nonlinear PDE. An optimal form of the elastic membrane described by the p-Laplacian is investigated. The boundary perturbation method due to Hadamard is applied in Sobolev spaces.

Je ll’ai vu: Perception-driven allomorphic optimization of French l’

This article aims to explain the optional gemination in the elided form of the French 3rdp. object pronounsleandla, i.e. before vowel, as in [ʒəllɛvy] forje l’ai vu(e)‘I saw him/her/it’. This geminate, which cannot be accounted for in purely phonological terms, is shown to follow from a boundary shift within the morphological sequence /il+lə/la+V/, providing the 3rdp. object pronouns with a new geminate allomorph before vowel; thereby, /ll/ can spread to the entire paradigm. It is argued (a) that the resulting allomorphy is the strategy found by speakers to eliminate the irregular allomorphy of the 3rdp. subject pronounilbefore consonant; (b) that a perception grammar is needed to capture the reasons for the new allomorphy.