Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title><jats:sec> <jats:title>Purpose</jats:title> <jats:p>Simultaneous effects of more than one global change driver on ecosystem functioning have rarely been assessed.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>We disentangled the effects of region encompassing climatic and edaphic conditions, forest-management intensity and community plant diversity on litterfall quantity, quality and turnover in 27 temperate forests across an environmental gradient.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>Region significantly influenced litterfall and organic layer mass and chemical quality and litter and element turnover. After accounting for the influence of region, increasing forest-management intensity (ForMI) significantly decreased litterfall mass, N, P and K concentrations and nutrient fluxes and slowed down litter and nutrient turnover. Because increasing ForMI reflected the man-made contributions of coniferous trees, these results can partly be attributed to the lower litterfall at our study sites and slower litter turnover of coniferous than deciduous trees. After accounting for the influences of region and ForMI, increasing diversity of the vascular plant community on the study plots measured as species richness or Shannon index significantly increased C and decreased N, P and S concentrations in litterfall. Together with the significantly decreased N and P concentrations in the organic layer with increasing plant diversity, these results indicated an increased within-stand nutrient-use efficiency and a more complete soil nutrient use with increasing plant diversity.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Our results demonstrate that increasing ForMI, which is associated with increasing conifer shares, leaves element stocks in the organic layer unchanged but slows down C turnover and thus increases temporary C storage in soil organic layers. Moreover, community vascular plant diversity helps close nutrient cycles.</jats:p> </jats:sec>

<jats:title>Abstract</jats:title><jats:sec> <jats:title>Background and aims</jats:title> <jats:p>Food production is threatened by direct climate change effects including drought. Indirect effects, including changes in plant-pathogen dynamics and increased susceptibility to pathogens, further exacerbate the risks. Root exudation, which plays a crucial role in plant defence against drought and pathogens, is influenced by both water stress and pathogens. However, the interactive effects of these abiotic and biotic factors are rarely studied.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>We conducted a controlled environment experiment to investigate the effects of moderate drought and simulated pathogen attack (using pipecolic acid, an inducer of systemic acquired resistance) on the rates of root exudation of total organic carbon (TOC) and total nitrogen (TN) of four tomato cultivars grown in potting soil.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>Drought increased the exudation of TOC and TN per unit of root area, while pipecolic acid did not have any significant effect. Furthermore, there was no interaction observed between the abiotic and biotic factors. However, due to the reduction in plant and root biomass caused by drought, the total exudation per plant remained similar between control and water-limited plants. Additionally, pipecolic acid reduced the carbon-to-nitrogen ratio of exudates and increased the total exudation of TN.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusion</jats:title> <jats:p>The increased exudation observed in drought-stressed plants may serve as a strategy to maintain root and rhizosphere activity despite reduced root growth. Notably, the impact of drought differed among the tested cultivars, highlighting their diverse levels of drought tolerance. This emphasises the importance of preserving a wide range of crop cultivars to ensure food security under increasing drought.</jats:p> </jats:sec>