José M. Grünzweig

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Atmospheric CO2 enrichment may stimulate plant growth directly through (1) enhanced photosynthesis or indirectly, through (2) reduced plant water consumption and hence slower soil moisture depletion, or the combination of both. Herein we describe gas exchange, plant biomass and species responses of five native or semi-native temperate and Mediterranean(More)
Associations between δ13C values and leaf gas exchanges and tree-ring or needle growth, used in ecophysiological compositions, can be complex depending on the relative timing of CO2 uptake and subsequent redistribution and allocation of carbon to needle and stem components. For palaeoenvironmental and dendroecological studies it is often interpreted in(More)
Are ecosystems in dry regions particularly responsive to atmospheric CO2 enrichment? We studied responses of semi-arid grassland assemblages from the northern Negev (Israel) to CO2 concentrations representative of the pre-industrial era, and early and mid to late 21st century (280, 440, and 600 µl l–1, respectively). Communities of 32 mostly annual species(More)
Soil respiration (SR) constitutes the largest flux of CO(2) from terrestrial ecosystems to the atmosphere. However, there still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 80 site-years for 57 forests, plantations, savannas, shrublands and grasslands(More)
This study explored possible advantages conferred by the phase shift between leaf phenology and photosynthesis seasonality in a semi-arid Pinus halepensis forest system, not seen in temperate sites. Leaf-scale measurements of gas exchange, nitrogen and phenology were used on daily, seasonal and annual time-scales. Peak photosynthesis was in late winter,(More)
Ecosystems in dry regions are generally low in productivity and carbon (C) storage. We report, however, large increases in C sequestration following afforestation of a semi-arid shrubland with Pinus halepensis trees. Using C and nitrogen (N) inventories, based in part on site-specific allometric equations, we measured an increase in the standing ecosystem C(More)
Land-use change is likely to be a major component of global change at high latitudes, potentially causing significant alterations in soil C and N cycling. We addressed the biogeochemical impacts of land-use change in fully replicated black spruce forests and agricultural fields of different ages (following deforestation) and under different management(More)
Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also(More)
The arid and semi-arid drylands of the world are increasingly recognized for their role in the terrestrial net carbon dioxide (CO2 ) uptake, which depends largely on plant litter decomposition and the subsequent release of CO2 back to the atmosphere. Observed decomposition rates in drylands are higher than predictions by biogeochemical models, which are(More)