1,721,104 research outputs found
Positive intercropping effects on biomass production are species-specific and involve rhizosphere enzyme activities: Evidence from a field study
No full text<jats:title>Abstract</jats:title><jats:p>Less attention has been given to soil enzymes that contribute to beneficial rhizosphere interactions in intercropping systems. Therefore, we performed a field experiment by growing faba bean, lupine, and maize in mono and mixed cultures in a moderately fertile soil. We measured shoot biomass and the kinetic parameters (maximal velocity (<jats:italic>V</jats:italic><jats:sub>max</jats:sub>) and Michaelis-constant (<jats:italic>K</jats:italic><jats:sub><jats:italic>m</jats:italic></jats:sub>)) of three key enzymes in the rhizosphere: Leucine-aminopeptidase (LAP), β-1,4-N-acetylglucosaminidase (NAG), and phosphomonoesterase (PHO). Faba bean benefitted in mixed cultures by greater shoot biomass production with both maize and lupine compared to its expected biomass in monoculture. Next, LAP and NAG kinetic parameters were less responsive to mono and mixed cultures across the crop species. In contrast, both the <jats:italic>V</jats:italic><jats:sub>max</jats:sub> and <jats:italic>K</jats:italic><jats:sub><jats:italic>m</jats:italic></jats:sub> values of PHO increased in the faba bean rhizosphere when grown in mixed cultures with maize and lupine. A positive relative interaction index for shoot P and N uptake for faba bean showed its net facilitative interactions in the mixed cultures. Overall, these results suggest that over-productivity in intercropping is crop-specific and the positive intercropping effects could be modulated by P availability. We argue that the enzyme activities involved in nutrient cycling should be incorporated in further research.</jats:p>
Erfassung und Bewertung von Ökosystemdienstleistungen im UNESCO-Biosphärenreservat Schaalsee
Full text linkEinfluss unterschiedlicher Lichtspektren und Temperaturen auf die Biomassen- und Wertstoffproduktion in Mikroalgen
Full text linkCauses and consequences of plant order of arrival on the structure and functioning of grassland communities
Full text linkNachhaltiger Märchenwald? Ein Beitrag zur Diskussion um Standards für populärwissenschaftliche Veröffentlichungen anhand einer Fallstudie zum Faktengehalt ausgewählter Werke Peter Wohllebens
Full text linkImproving agricultural nutrient use efficiencies: effects of crop rotation, high carbon amendments and fertilizer application timing on barley
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Testing theories for ecological restoration: effects of plant-plant interactions and plant order of arrival on assembly and on above- and belowground productivity
Full text linkImpact of above- and below-ground invertebrates on temporal and spatial stability of grassland of different diversity
No full text1. Recent theoretical studies suggest that the stability of ecosystem processes is not governed by diversity per se, but by multitrophic interactions in complex communities. However, experimental evidence supporting this assumption is scarce. 2. We investigated the impact of plant diversity and the presence of above- and below-ground invertebrates on the stability of plant community productivity in space and time, as well as the interrelationship between both stability measures in experimental grassland communities. 3. We sampled above-ground plant biomass on subplots with manipulated above- and below-ground invertebrate densities of a grassland biodiversity experiment (Jena Experiment) 1, 4 and 6 years after the establishment of the treatments to investigate temporal stability. Moreover, we harvested spatial replicates at the last sampling date to explore spatial stability. 4. The coefficient of variation of spatial and temporal replicates served as a proxy for ecosystem stability. Both spatial and temporal stability increased to a similar extent with plant diversity. Moreover, there was a positive correlation between spatial and temporal stability, and elevated plant density might be a crucial factor governing the stability of diverse plant communities. 5. Above-ground insects generally increased temporal stability, whereas impacts of both earthworms and above-ground insects depended on plant species richness and the presence of grasses. These results suggest that inconsistent results of previous studies on the diversity–stability relationship have in part been due to neglecting higher trophic-level interactions governing ecosystem stability. 6. Changes in plant species diversity in one trophic level are thus unlikely to mirror changes in multitrophic interrelationships. Our results suggest that both above- and below-ground invertebrates decouple the relationship between spatial and temporal stability of plant community productivity by differently affecting the homogenizing mechanisms of plants in diverse plant communities. 7. Synthesis. Species extinctions and accompanying changes in multitrophic interactions are likely to result not only in alterations in the magnitude of ecosystem functions but also in its variability complicating the assessment and prediction of consequences of current biodiversity loss
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