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Amid urbanization, studying leaf functional traits of woody plants in urban environments is essential for understanding how urban green spaces function and how they can be effectively managed sustainably. In this study, we investigated the effects of different growing conditions on the morpho-physiological traits of Populus laurifolia and Ulmus pumila across five contrasting urban sites. The leaf area (LA), leaf length (LL), leaf width (LW), leaf biomass (LB), specific leaf area (SLA), leaf chlorophyll concentration, chlorophyll fluorescence parameters, leaf water potential at predawn (Ψpd) and midday (Ψmd), leaf performance index (PIabs), and phenotypic plasticity index (PPI) were compared across five contrasting urban sites. The soil chemical and physical properties were also compared between sites. There were significant differences in soil physicochemical characteristics between sites. We found significant effects of site on most of the morpho-physiological traits measured, except for Ψmd. The leaf chlorophyll concentration of P. laurifolia and U. pumila varied significantly between sites. The Ψpd was significantly different between years and sites. In U. pumila, the mean PPI for morphological traits (0.20) was lower than that for physiological traits (0.21). In conclusion, we revealed significant variations in the morpho-physiological traits of P. laurifolia and U. pumila across the five urban sites. Hence, long-term, large-scale studies are recommended to examine how diverse species respond to different urban growing conditions and to include other ecologically important plant traits for a better understanding of urban trees in a changing environment. [ABSTRACT FROM AUTHOR]

Soil salinity is major threat to crop growth and reducing cultivated land areas and salt-resistant crops have been required to sustain agriculture in salinized areas. This original research was performed to determine the effectiveness of MgSO4 (MS) and CaSO4 (CS) for each species and assess changes in the physiology and growth of fodder crops after short and long-term salt stress. Six treatments (CON (control); NaCl (NaCl 100 mM); 1 MS (1 mM MgSO4 + 100 mM NaCl); 2 MS (2 mM MgSO4 + 100 mM NaCl); 7.5 CS (7.5 mM CaSO4 + 100 mM NaCl); and 10 CS (10 mM CaSO4 + 100 mM NaCl)) were applied to Red clover (Trifolium pratense) and Tall fescue (Festuca arundinacea) under greenhouse conditions. Cultivars were evaluated based on their dry weights, physiological parameters, forage quality, and ion concentrations. The biomass of both species decreased significantly under NaCl treatments and increased under the MS and CS treatments compared to solely salinity treatments. Salinity caused a decrease in the photosynthetic rate, but compared to CON, the MS and CS treatments yielded superior results. Moreover, the Na+/K+ ratio increased as Na+ concentration increased but crop quality (CP, NDF, ADF) did not show significant differences under salinity. Overall, we concluded that these T. pratense and F. arundinacea species demonstrated various responses to salinity, MS, and CS by different physiological and morphological parameters and it turned out to be efficient under salinity stress. [ABSTRACT FROM AUTHOR]

Poor seedling establishment and growth can be a result of the limitation of light and soil resources in the forest understory. Here, we investigate the interacting effects of stand and soil characteristics on the seedling growth of deciduous species (Fraxinus rhynchophylla and Zelkova serrata) and evergreen species (Pinus koraiensis) through a 3-year intersite experiment in two contrasting forest stands. Seedlings were grown in both oak and pine stands using two different soil types, i.e., gray-brown forest soil (GB) and red-yellow forest soil (RY). Soil physicochemical properties, light intensity, tree-seedling height, root-collar diameter (RCD), and biomass growth were analyzed between two stands and/or soil types. Light availability was generally more abundant in the pine stand (mean: 1074.08 lx or 20.25%) than the oak stand (mean: 424.33 lx or 9.20%) throughout the year. The height and RCD growth of fast-growing and deciduous F. rhynchophylla and Z. serrata were higher in the pine than in the oak stand, particularly in GB soil. The growth of the slow-growing and evergreen P. koraiensis was not affected by the forest stand, except for its higher root growth in the oak stand and RY soil. Therefore, abundant light availability can enhance the growth and seedling establishment of F. rhynchophylla and Z. serrata in the pine-stand understory. Contrarily, P. koraiensis may be planted in the understory regardless of light condition, but with a slower growth rate. [ABSTRACT FROM AUTHOR]

Desertification is impeding the implementation of reforestation efforts in Mongolia. Many of these efforts have been unsuccessful due to a lack of technical knowledge on water and nutrient management strategies, limited financial support, and short-lived rainfall events. We investigated the effects of irrigation and fertilization on the morphophysiological traits of Populus sibirica Hort. Ex Tausch and Ulmus pumila L. and to suggest irrigation and fertilization strategies for reforestation. Different irrigation and fertilizer treatments were applied: no irrigation, 2 L h−1, 4 L h−1, and 8 L h−1 of water; no fertilizer, 2 L h−1 + NPK, 4 L h−1 + NPK, and 8 L h−1 + NPK; and no compost, 2 L h−1 + compost, 4 L h−1 + compost, and 8 L h−1 + compost. The leaf area (LA) and specific leaf area (SLA) of both species responded positively to 4 and 8 L h−1. Results also showed that the addition of either NPK or compost to 4 or 8 L h−1 irrigation resulted in a higher LA, SLA, and leaf biomass (LB). Total chlorophyll content decreased with irrigation in both species. The same pattern was detected when a higher amount of irrigation was combined with fertilizers. Lastly, we found that both diurnal and seasonal leaf water potential of plants grown in 4 or 8 L h−1 were significantly higher than those of plants grown in control plots. Therefore, 4 or 8 L h−1 with either NPK or compost has shown to be the optimal irrigation and fertilization strategy for the species in an arid and semiarid region of Mongolia. Results should provide us with a better understanding of tree responses to varying amounts of irrigation with or without fertilizer in pursuit of sustainable forest management in arid and semiarid ecosystems. [ABSTRACT FROM AUTHOR]