Integrated global assessment of the natural forest carbon potential

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2,3,4,5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets

A widespread compositionally bimodal tephra sourced from Volc\ue1n Melimoyu (44\ub0S, Northern Patagonian Andes): Insights into magmatic reservoir processes and opportunities for regional correlation

We describe the stratigraphy, age, constituent geochemistry and phenocryst thermobarometry of a closely spaced Holocene tephra couplet from Volc\ue1n Melimoyu (VMm), located in the Northern Patagonian Andes. The lower tephra unit (La Junta Tephra, Mm-1) is distinctly banded comprising a dominant lower layer of rhyodacitic ( 3c70% SiO2) pumiceous ash and lapilli (Mm-1p) that abruptly transitions to a subordinate upper scoriaceous layer (Mm-1s) of basaltic andesite composition ( 3c53% SiO2). This bimodality within Mm-1 contrasts significantly with the closely overlying Santa Ana Tephra (Mm-2) that has a homogeneous trachyte-dacite ( 3c63% SiO2) composition and is intermediate between the two magmatic end members of Mm-1. We propose a genetic affiliation between Mm-1 and Mm-2, and that the latter event likely represents a hybridised-remnant of those discrete magmas involved in the earlier Mm-1 eruption. To test this hypothesis we applied whole rock elemental mixing and fractional crystallisation model to reproduce the composition and crystallinity of Mm-2. Results indicate that Mm-2 can be reproduced by mixing 3c70% Mm-1p with 3c30% Mm-1s, with subsequent 3c13% fractional crystallisation of plagioclase, and minor amphibole, orthopyroxene, magnetite and biotite. Equilibrium P-T conditions calculated from Mm-1p phenocrysts point towards magma residency at moderately shallow depths (200\u2013290 MPa, 3c7\u201310-km depth, 850\u20131000 \ub0C), whereas Mm-1s phenocrysts indicate higher overall P-T conditions (240\u2013480 MPa, 3c8.5\u201317-km depth, 1080\u20131150 \ub0C). P-T conditions determined for Mm-2 ( 3c290 MPa, 3c10-km depth, 930\u20131000 \ub0C) are similar to those of Mm-1p. There is no physical and/or geochemical evidence of mafic magma involvement in the Mm-2 eruption. Similar compositionally bimodal tephra are known from other Northern Patagonian Andean centres (i.e. Playas Blanca-Negra Tephra, Antillanca; Lepue Tephra, Michimahuida; Ho and H3 eruptions of Hudson) suggests that the intrusion of mafic magma into more silicic magma bodies is a common occurrence throughout this Andean sector. These widely dispersed, compositionally bimodal tephra not only provide key insights into pre-eruptive magmatic conditions and triggering processes, but can also be readily identified geochemically, and thereby be more fully utilised within future hazard- and paleoenvironmental-related studies

Marital Satisfaction and Depression: A Replication of the Marital Discord Model in a Latino Sample

The Marital Discord Model of Depression maintains that marital discord is an important antecedent in the development of depression. Although empirical evidence supports this premise, none of this research has been done with Latinos. The purpose of this study was to test the longitudinal relationship between marital satisfaction and depression among 99 Brazilian women. Using structural equation modeling, results indicated that marital satisfaction was a strong predictor of depression 2 years later. Marital satisfaction was also related to co-occurring depression. These results provide evidence that the Marital Discord Model of Depression is an appropriate theoretical model for the conceptualization of marital discord and depression with Latina women and suggest the potential utility of using couples therapy for treating depression among this population