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The structure and function of aquatic communities in reservoir ecosystems can be strongly affected by dam construction. The Ecopath model is an effective tool that reveals the food web structure and pathways of energy flows. In this study, it was applied to analyze the trophic interactions and energy flows within the Manwan reservoir ecosystem on Lancang River in southwest China. Ecotrophic efficiency (EE) was calculated and the value of EE was 0.073 for the least-exploited piscivorous fishes (top predators) and 0.93 for the most-exploited zoobenthos. Four estimated trophic levels of the groups varied from 1 for detritus and phytoplankton (level I) to 3.69 for piscivorous fishes (level IV) and the remaining groups were mainly at trophic levels II and III. Food web structures and interactions were well represented by a linear food chain that was dominated by a detritus pathway; that is, energy flows from detritus were as important as phytoplankton in the web. The proportion of total energy flow originating from detritus was 46% while the other 54% came from primary producers. The average transfer efficiencies between trophic levels were 16.6% from primary producer and 15.7% from detritus. Total system throughput was found to be 5550 t km ¡2 yr ¡1 , total primary production/total respiration ratio was 2.46, and the ascendency index was 27.4%. These results showed that Manwan reservoir ecosystem was an immature ecosystem and still at its development stage. These results are helpful for biodiversity preservation and the understanding and monitoring of reservoir ecosystems which are key resources for fish and other aquatic organisms.

Leaf traits play key roles in plant resource acquisition and ecosystem processes; however, whether the effects of environment and phylogeny on leaf traits differ between herbaceous and woody species remains unclear. To address this, in this study, we collected data for five key leaf traits from 1,819 angiosperm species across 530 sites in China. The leaf traits included specific leaf area, leaf dry matter content, leaf area, leaf N concentration, and leaf P concentration, all of which are closely related to trade-offs between resource uptake and leaf construction. We quantified the relative contributions of environment variables and phylogeny to leaf trait variation for all species, as well as for herbaceous and woody species separately. We found that environmental factors explained most of the variation (44.4–65.5%) in leaf traits (compared with 3.9–23.3% for phylogeny). Climate variability and seasonality variables, in particular, mean temperature of the warmest and coldest seasons of a year (MTWM/MTWQ and MTCM/MTCQ) and mean precipitation in the wettest and driest seasons of a year (MPWM/MPWQ and MPDM/MPDQ), were more important drivers of leaf trait variation than mean annual temperature (MAT) and mean annual precipitation (MAP). Furthermore, the responses of leaf traits to environment variables and phylogeny differed between herbaceous and woody species. Our study demonstrated the different effects of environment variables and phylogeny on leaf traits among different plant growth forms, which is expected to advance the understanding of plant adaptive strategies and trait evolution under different environmental conditions.

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