<?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%">Otieno, D. O.</style></author><author><style face="normal" font="default" size="100%">Mirzaei, H.</style></author><author><style face="normal" font="default" size="100%">Hussain, M. Z.</style></author><author><style face="normal" font="default" size="100%">Li, Y. L.</style></author><author><style face="normal" font="default" size="100%">Schmidt, M. W. T.</style></author><author><style face="normal" font="default" size="100%">Wartinger, M.</style></author><author><style face="normal" font="default" size="100%">Jung, E.</style></author><author><style face="normal" font="default" size="100%">Ribeiro, N.</style></author><author><style face="normal" font="default" size="100%">Pereira, J. S.</style></author><author><style face="normal" font="default" size="100%">Tenhunen, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Herbaceous layer development during spring does not deplete soil nitrogen in the Portuguese montado</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Arid Environments</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biomass development of the herbaceous vegetation</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">pasture</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant and soil nitrogen pools</style></keyword><keyword><style  face="normal" font="default" size="100%">Portuguese montado</style></keyword><keyword><style  face="normal" font="default" size="100%">Root distribution and nutrient uptake</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil moisture</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0140196310002922</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">75</style></volume><pages><style face="normal" font="default" size="100%">231 - 238</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Nitrogen (N) content in the soil and in the herbaceous biomass were monitored during spring of 2004e2006 to determine how the herbaceous layer development inﬂuences soil N availability in the montado ecosystem of southern Portugal. Highest (246.6 52.7 g m2 ) and lowest (123.2 89.5 g m2 ) peak biomass occurred in 2006 and 2005 respectively. Total soil N within the top 20 cm soil proﬁle ranged between 0.2 0.1% in February and 0.41 0.2% in May, while available soil N was lowest (5 2 mg g 1 soil) in February but increased three-to-ﬁve fold in March and was &gt;17.5 mg g 1 soil at senescence in May. Signiﬁcant (p &lt; 0.001) increase in total N in the aboveground pool occurred between February and May. There was however, no decay in soil N content. Instead, the herbaceous vegetation enhanced soil N input and N retention in the ecosystem. Most of the herbaceous plants were annuals with large reserves of organic N at senescence, which returned to the soil as detritus. The herbaceous vegetation is a critical component of the montado that contributes to N recharge and cycling within the ecosystem</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Assessment and up-scaling of CO2 exchange by patches of the herbaceous vegetation mosaic in a Portuguese cork oak woodland</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest Meteorology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0168192308000981</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">148</style></volume><pages><style face="normal" font="default" size="100%">1318 - 1331</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Long-term eddy covariance measurements over a montado oak woodland in southern Portugal have documented a vulnerability to predicted decreases in springtime rainfall, since water availability during spring limits annual CO2 gain, the growth of fodder for animals, and the production of cork by Quercus suber. The current study examined CO2 exchange of three different herbaceous vegetation components distributed over montado landscapes and within the footprint of long-term landscape eddy covariance monitoring studies. Simultaneous measurements with eddy covariance at two sites and with manually operated chambers at multiple locations revealed that slow drainage of shallow basins, the onset of drying at higher sites and a high release of CO2 below tree canopies signiﬁcantly inﬂuenced the overall course of montado ecosystem gas exchange during the spring. Hyperbolic light response models were employed to up-scale and compare herbaceous gas exchange with landscape net ecosystem CO2 ﬂux. The up-scaling demonstrates the importance of the herbaceous understory in determining annual carbon balance of the montado and suggests a relatively small additional CO2 uptake by the tree canopies and boles, i.e., by the aboveground tree compartment, during springtime. Annual ﬂux totals obtained during the extremely dry year 2005 and a normal precipitation year 2006 for the oak woodland and a nearby grassland were essentially the same, indicating that both ecosystems similarly exploit available resources. Based on comparisons with additional temperate grasslands, we can visualize the montado herbaceous cover as a typical European grassland canopy, but where temperature ﬂuctuations in winter control uptake, and where total production depends on springtime rainfall as it controls phenological events and eventually dieback of the vegetation. On the other hand, tree canopies remain active longer during late spring and early summer, modifying the montado response from that of grassland. Uncertainties in ﬂux estimates via both chamber and eddy covariance methodologies currently prevent a full understanding of vegetation/atmosphere coupling, of the recycling of CO2 between the understory communities and trees, and of relationships between exchange rates of individual components of the vegetation mosaic and overall carbon and water balances in montado landscapes.</style></abstract><issue><style face="normal" font="default" size="100%">8-9</style></issue></record></records></xml>