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Advancements in planting and fertilization strategies can improve forage productivity in animal husbandry ecosystems. However, the way in which soil microbes regulate forage yield during this process remains unclear and limits our understanding of the underlying mechanisms that determine the impact of agriculture on forage yield. Here, a 4-year field experiment was conducted using three levels of planting density (high at 20 kg·hm−2, medium at 15 kg·hm−2, and low at 10 kg·hm−2) and two levels of fertilization (high at 150 kg·hm−2 P 2 O 5 with 150 kg·hm−2 of urea and low at 75·kg·hm−2 P 2 O 5 with 75 kg·hm−2 of urea) in nutrient-deficient flood lands. This study aimed to survey the forage yield, soil variables, community features (including diversity, community composition, network patterns, and potential functions) of soil bacteria and fungi, and the linkages. The findings indicated that planting density and fertilization had remarkable impacts on bacterial and fungal diversity, co-occurrence network patterns, and the nitrogen-cycle-related potential of bacteria (including nitrogen fixation, nitrification, denitrification, aerobic ammonia oxidation, and nitrite respiration). The combination of medium planting density with low fertilization resulted in higher levels of forage production, bacterial Shannon diversity, N-fixation potential, and network modularity than did the other treatments. Furthermore, significant positive correlations were observed among bacterial diversity, network modularity, available soil nutrients, and forage production. The soil that supported a large number of bacterial taxa with co-occurring network modularity had high soil nutrient levels and forage production. Structural equation modeling and linear regression models demonstrated that the contribution of soil bacteria to forage yield was higher than that of fungi and that planting density and fertilization indirectly associated microbial function by altering bacterial diversity and network modularization, which also positive associated forage production. Therefore, there is a need to emphasize bacterial alpha-diversity and potential interaction patterns to sustain forage yields, which leads to improvements in future planting and fertilization strategies in animal husbandry ecosystems. [ABSTRACT FROM AUTHOR]

Background and aims: Determining which strategies confer a competitive advantage in variable environments with strong short-term resource fluctuations (i.e., seasonal drought and flooding) is critical for understanding ecosystem structure and function, and predicting how ecosystems will respond to global change. Here, we ask how functional traits of plant species vary in response to drought and flooding and whether trait plasticity is a better predictor of plants' cover than average functional trait values. Methods: We transplanted vegetative recruits (similar size and age) of eight common species from a moderately grazed alpine wetland in the Eastern Tibetan Plateau to a common garden where we evaluated the trait responses of these species to drought and flooding. We also measured the coverage, biomass, and height of these plant species in the field communities. Results: The leaf morphological and physiological traits of these eight species generally showed different responses to drought and flood conditions. Variation (plasticity) of leaf morphological or physiological traits rather than average values of these traits were better predictors of cover and biomass in the field community. Species with lower plasticity in leaf morphological traits had higher plasticity in leaf physiology and the higher coverage and biomass in the field community. Conclusions: Our results suggest that the ability to quickly adjust leaf physiology to changing environmental conditions provides an advantage in this ecosystem, where intra-annual rainfall variability is high and thus resource fluctuations are pulsed in time. In contrast, greater functional trait plasticity in leaf morphology was a disadvantage, possibly because the benefits of these adjustments did not outweigh their initial costs. [ABSTRACT FROM AUTHOR]