Search results for "BIOSPHERE"

2018

AbstractWhile significant efforts have been invested in reconstructing the early evolution of the Earth’s atmosphere–ocean–biosphere biogeochemical nitrogen cycle, the potential role of an early continental contribution by a terrestrial, microbial phototrophic biosphere has been largely overlooked. By transposing to the Archean nitrogen fluxes of modern topsoil communities known as biological soil crusts (terrestrial analogs of microbial mats), whose ancestors might have existed as far back as 3.2 Ga ago, we show that they could have impacted the evolution of the nitrogen cycle early on. We calculate that the net output of inorganic nitrogen reaching the Precambrian hydrogeological system c…

Global Scale IB AMSR2 Vegetation Optical Depth at X-Band

2021

Vegetation Optical Depth (VOD) plays an increasingly important role in studying global carbon, water and energy transformation [1], [2]. This study explores the performance of the X-MEB (X-band microwave emission of the biosphere) model at global scale. Similar to the L-MEB model, the X-MEB model, built by INRAE (Institut national de recherche pour l'agriculture, l'alimentation et l'environnement) Bordeaux, aims to retrieve VOD (referred to as IB X-VOD) at X-band. To avoid the ill-posed problem caused by retrieving two parameters of interest (soil moisture (SM) and VOD) from mono-angular and dual-polarized observations (AMSR2), which are strongly correlated, we used the ERA5 SM product as a…

Real-time measurements of Hg0 and H2S at La Solfatara Crater (Campi Flegrei, Southern Italy) and Mt. Amiata volcano (Siena, Central Italy): a new geo…

2014

Spatiotemporal patterns of dunlin (Calidris alpina) in continental lakes of the Iberian Peninsula

2018

AbstractSpatiotemporal dynamics may present different levels of regional or local stability, generally attributed to local habitat and landscape factors, reflecting the tolerances and ecological requirements of the populations. In this study, we examined the variations of dunlin abundance and occurrence in twenty-three wetlands of the “La Mancha Húmeda” Biosphere Reserve, central Spain, between October 2010 and July 2017. In addition, we observed the variations of local abundance in the lakes of the Manjavacas lagoon complex, seeking to understand the factors that determine the local movements of the wintering individuals. Eleven lakes had records of dunlin, but most of individuals (ca. 90%…

Remote sensing of vegetation dynamics in agro-ecosystems using smap vegetation optical depth and optical vegetation indices

2017

The ESA's SMOS and the NASA's SMAP missions, launched in 2009 and 2015, respectively, are the first two missions having on-board L-band microwave sensors, which are very sensitive to the water content in soils and vegetation. Focusing on the vegetation signal at L-band, we have implemented an inversion approach for SMAP that allows deriving vegetation optical depth (VOD, a microwave parameter related to biomass and plant water content) alongside soil moisture, without reliance on ancillary optical information on vegetation. This work aims at using this new observational data to monitor the phenology of crops in major global agro-ecosystems and enhance present agricultural monitoring and pre…

Ecosystem services provided by marine and freshwater phytoplankton

2021

AbstractPhytoplankton, the ecological group of microalgae adapted to live in apparent suspension in water masses, is much more than an ecosystem’s engineer. In this opinion paper, we use our experience as phytoplankton ecologists to list and highlight the services provided by phytoplankton, trying to demonstrate how their activity is fundamental to regulate and sustain Life on our Planet. Although the number of services produced by phytoplankton can be considered less numerous than that produced by other photosynthetic organisms, the ubiquity of this group of organisms, and their thriving across oceanic ecosystems make it one of the biological engines moving our biosphere. Supporting servic…

Optical types of inland and coastal waters

2017

Inland and coastal waterbodies are critical components of the global biosphere. Timely monitoring is necessary to enhance our understanding of their functions, the drivers impacting on these functions and to deliver more effective management. The ability to observe waterbodies from space has led to Earth observation (EO) becoming established as an important source of information on water quality and ecosystem condition. However, progress toward a globally valid EO approach is still largely hampered by inconsistences over temporally and spatially variable in-water optical conditions. In this study, a comprehensive dataset from more than 250 aquatic systems, representing a wide range of condi…

Soil is the best testifier of the diachronous dawn of the Anthropocene

2021

Humans act at worldwide scale as a growing geomorphic agent since mid‐Holocene (8,200–4,200 y BP) through the pervasive impacts of domestication, deforestation, agriculture, urbanization, and mining. The concept of Anthropocene has been introduced exactly to indicate the timespan in which humans have joined with other natural forces in impacting the outermost shell of the planet and the biosphere. Soils, which are the Earth's skin, are sensitive archives of any major human‐induced local to global change. Especially when buried, soils can permanently preserve the primordial traces of a significant impact of man on the environment, which occurred at different times and rates in different area…

Towards an advanced atmospheric chemistry-enabled ESM with dynamic land surface processes: Part I - Linking LPJ-GUESS (v4.0) with EMAC modelling syst…

2018

Earth System Models (ESMs) are invaluable tools that have emerged from decades of research modelling the earth system. Central to this development has been the coupling of previously separate model types, such as ocean, atmospheric and vegetation models, to provide interactive feedbacks between these earth system components. Here we present the initial steps of coupling LPJ-GUESS, a dynamic global vegetation model, to EMAC, an atmospheric chemistry enabled atmosphere-ocean general circulation model. The LPJ-GUESS framework includes a comparatively detailed tree-individual based model of vegetation dynamics, a crop and managed-land scheme, a nitrogen cycle and a choice of fire models; and he…

The Oblivion of Demography in Sustainability’s Studies

2017

[RESUMEN] A lo largo de la historia del Homo sapiens, su número se ha mantenido muy reducido y hubo que esperar a principios del siglo XIX para que alcanzara los mil millones. Se inició entonces un rápido crecimiento y durante el siglo XX la población mundial casi se cuadriplicó, superando los 6000 millones, lo que llevó a estudiar, con lógica preocupación, los posibles efectos de esta explosión demográfica sobre el conjunto de la biosfera y sobre la propia especie humana. Hoy, sin embargo, cuando se han sobrepasado los 7500 millones y la población mundial sigue aumentando en unos 80 millones cada año, la problemática demográfica ha dejado de tener una presencia relevante en los estudios y …