<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Andreetta, Anna</style></author><author><style face="normal" font="default" size="100%">Ciampalini, Rossano</style></author><author><style face="normal" font="default" size="100%">Moretti, Pierpaolo</style></author><author><style face="normal" font="default" size="100%">Vingiani, Simona</style></author><author><style face="normal" font="default" size="100%">Poggio, Giorgio</style></author><author><style face="normal" font="default" size="100%">Matteucci, Giorgio</style></author><author><style face="normal" font="default" size="100%">Tescari, Francesca</style></author><author><style face="normal" font="default" size="100%">Carnicelli, Stefano</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Forest humus forms as potential indicators of soil carbon storage in Mediterranean environments</style></title><secondary-title><style face="normal" font="default" size="100%">Biology and Fertility of Soils</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon pools</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Sequestration</style></keyword><keyword><style  face="normal" font="default" size="100%">humus forms</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean forests</style></keyword><keyword><style  face="normal" font="default" size="100%">stabilization</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s00374-010-0499-z</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">47</style></volume><pages><style face="normal" font="default" size="100%">31 - 40</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The aim of this work was to investigate the potential of forest humus forms as indicators of soil C storage. To this purpose, Mediterranean forest soils in Southern and Central Italy were examined. Sites differed for elevation, climate, parent material and vegetation conditions, while summer drought was the common ecological factor. A morpho-functional criterion, based on holorganic layers thickness and A horizon properties, was used to classify humus forms, which ranged from Dysmoder to Eumull. Such variability allowed understanding of factors influencing organic matter storage. The relations between carbon stock and humus form were investigated for the topsoil layer (0–20 cm), which was supposed to contain the soil C pools most sensitive to climate change. We found that humus forms can be grouped in statistically different populations, with respect to topsoil C stocks. The use of A horizon structure was the main diagnostic criterion and represented the most effective approach to humus classification in Mediterranean conditions. It appears that humus forms have a clear potential as indicators of organic carbon status in Mediterranean forest soils.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hemming, Deborah</style></author><author><style face="normal" font="default" size="100%">Yakir, Dan</style></author><author><style face="normal" font="default" size="100%">Ambus, Per</style></author><author><style face="normal" font="default" size="100%">Aurela, Mika</style></author><author><style face="normal" font="default" size="100%">Besson, Cathy</style></author><author><style face="normal" font="default" size="100%">Black, Kevin</style></author><author><style face="normal" font="default" size="100%">Buchmann, Nina</style></author><author><style face="normal" font="default" size="100%">Burlett, Regis</style></author><author><style face="normal" font="default" size="100%">CESCATTI, ALESSANDRO</style></author><author><style face="normal" font="default" size="100%">Clement, Robert</style></author><author><style face="normal" font="default" size="100%">Gross, Patrick</style></author><author><style face="normal" font="default" size="100%">Granier, André</style></author><author><style face="normal" font="default" size="100%">Grünwald, Thomas</style></author><author><style face="normal" font="default" size="100%">Havrankova, Katarina</style></author><author><style face="normal" font="default" size="100%">Janous, Dalibor</style></author><author><style face="normal" font="default" size="100%">Janssens, Ivan A</style></author><author><style face="normal" font="default" size="100%">Knohl, Alexander</style></author><author><style face="normal" font="default" size="100%">Östner, Barbara K</style></author><author><style face="normal" font="default" size="100%">Kowalski, Andrew</style></author><author><style face="normal" font="default" size="100%">Laurila, Tuomas</style></author><author><style face="normal" font="default" size="100%">Mata, Catarina</style></author><author><style face="normal" font="default" size="100%">Marcolla, Barbara</style></author><author><style face="normal" font="default" size="100%">Matteucci, Giorgio</style></author><author><style face="normal" font="default" size="100%">Moncrieff, John</style></author><author><style face="normal" font="default" size="100%">Moors, Eddy J</style></author><author><style face="normal" font="default" size="100%">Osborne, Bruce</style></author><author><style face="normal" font="default" size="100%">Pereira, João Santos</style></author><author><style face="normal" font="default" size="100%">Pihlatie, Mari</style></author><author><style face="normal" font="default" size="100%">Pilegaard, Kim</style></author><author><style face="normal" font="default" size="100%">Ponti, Francesca</style></author><author><style face="normal" font="default" size="100%">Rosova, Zuzana</style></author><author><style face="normal" font="default" size="100%">Rossi, Federica</style></author><author><style face="normal" font="default" size="100%">Scartazza, Andrea</style></author><author><style face="normal" font="default" size="100%">Vesala, Timo</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Pan-European δ13C values of air and organic matter from forest ecosystems</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carboeuroflux</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 fluxes</style></keyword><keyword><style  face="normal" font="default" size="100%">ecosystem carbon budget</style></keyword><keyword><style  face="normal" font="default" size="100%">ecosystem respiration</style></keyword><keyword><style  face="normal" font="default" size="100%">isotopic discrimination</style></keyword><keyword><style  face="normal" font="default" size="100%">Stable isotopes</style></keyword><keyword><style  face="normal" font="default" size="100%">δ13C</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Science Ltd</style></publisher><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">1065-1093</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We present carbon stable isotope, δ13C, results from air and organic matter samples collected during 98 individual field campaigns across a network of Carboeuroflux forest sites in 2001 (14 sites) and 2002 (16 sites). Using these data, we tested the hypothesis that δ13C values derived from large-scale atmospheric measurements and models, which are routinely used to partition carbon fluxes between land and ocean, and potentially between respiration and photosynthesis on land, are consistent with directly measured ecosystem-scale δ13C values. In this framework, we also tested the potential of δ13C in canopy air and plant organic matter to record regional-scale ecophysiological patterns. Our network estimates for the mean δ13C of ecosystem respired CO2 and the related ‘discrimination’ of ecosystem respiration, δer and Δer, respectively, were −25.6±1.9‰ and 17.8 ±2.0‰ in 2001 and −26.6±1.5‰ and 19.0±1.6‰ in 2002. The results were in close agreement with δ13C values derived from regional-scale atmospheric measurement programs for 2001, but less so in 2002, which had an unusual precipitation pattern. This suggests that regional-scale atmospheric sampling programs generally capture ecosystem δ13C signals over Europe, but may be limited in capturing some of the interannual variations. In 2001, but less so in 2002, there were discernable longitudinal and seasonal trends in δer. From west to east, across the network, there was a general enrichment in 13C (∼3‰ and ∼1‰ for the 2 years, respectively) consistent with increasing Gorczynski continentality index for warmer and drier conditions. In 2001 only, seasonal 13C enrichment between July and September, followed by depletion in November (from about −26.0‰ to −24.5‰ to −30.0‰), was also observed. In 2001, July and August δer values across the network were significantly related to average daytime vapor pressure deficit (VPD), relative humidity (RH), and, to a lesser degree, air temperature (Ta), but not significantly with monthly average precipitation (Pm). In contrast, in 2002 (a much wetter peak season), δer was significantly related with Ta, but not significantly with VPD and RH. The important role of plant physiological processes on δer in 2001 was emphasized by a relatively rapid turnover (between 1 and 6 days) of assimilated carbon inferred from time-lag analyses of δer vs. meteorological parameters. However, this was not evident in 2002. These analyses also noted corresponding diurnal cycles of δer and meteorological parameters in 2001, indicating a rapid transmission of daytime meteorology, via physiological responses, to the δer signal during this season. Organic matter δ13C results showed progressive 13C enrichment from leaves, through stems and roots to soil organic matter, which may be explained by 13C fractionation during respiration. This enrichment was species dependent and was prominent in angiosperms but not in gymnosperms. δ13C values of organic matter of any of the plant components did not well represent short-term δer values during the seasonal cycle, and could not be used to partition ecosystem respiration into autotrophic and heterotrophic components.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>7</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Scarascia-Mugnozza, Giuseppe E</style></author><author><style face="normal" font="default" size="100%">Angelis, Paolo De</style></author><author><style face="normal" font="default" size="100%">Matteucci, Giorgio</style></author><author><style face="normal" font="default" size="100%">Kuzminsky, Elena</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Fakhri A. Bazzaz BT - Carbon Dioxide and Communities, Populations</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">14 - Carbon Metabolism and Plant Growth under Elevated CO2 in a Natural Quercus ilex L. “Macchia” Stand</style></title><secondary-title><style face="normal" font="default" size="100%">Carbon Dioxide, Populations, and Communities</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acclimation processes (PG)</style></keyword><keyword><style  face="normal" font="default" size="100%">biomass allocation</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Elevated CO2</style></keyword><keyword><style  face="normal" font="default" size="100%">long-term exposure</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean macchia</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">Academic Press</style></publisher><pub-location><style face="normal" font="default" size="100%">San Diego</style></pub-location><pages><style face="normal" font="default" size="100%">209-230</style></pages><isbn><style face="normal" font="default" size="100%">978-0-12-420870-4</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Publisher Summary This chapter examines the impact of long-term exposure to elevated CO2 concentration in a natural Mediterranean community dominated by Quercus ilex (high &quot;macchia&quot;). The research emphasizes on measurements of carbon metabolism and light energy utilization by the leaves to assess the physiological responses that subtend growth rather than just measuring short-term biomass increments at the tree level alone. Given the relevance of the Mediterranean woodland communities from an economical and environmental perspective, it is critical to be able to predict the possible effects of global change on these ecosystems and to eventually adopt adequate mitigation strategies. The interaction between carbon metabolism and biomass partitioning in woody plants is also regulated by nutrient availability. In the nutrient-limited Mediterranean environment, a CO2 increase may in part relieve this limitation by a greater efficiency of nutrient utilization, especially in tree species, characterized by a large proportion of their biomass allocated to components with low nutrient cost. These limitations are likely to moderate the responses of plants and communities to a global change, particularly to increases in atmospheric CO2 and biosphere warming. After a three-year period, the community responses to elevated CO2 indicate a wide range of acclimation processes by tree and shrub species in relation to their different ecological strategies.</style></abstract></record></records></xml>