Effect of woody plant expansion on decomposition of fine root mixtures in a grass-dominated temperate wetland

Wetlands Ecology and Management - Little is known about the effect of woody plant expansion on decomposition of root mixtures in grass-dominant temperate wetlands. Here, we collected fine roots...     

Differential responses of litter decomposition in the air and on the soil surface to shrub encroachment in a graminoid-dominated temperate wetland

Plant and Soil - Graminoid-dominated wetlands have been subjected to widespread shrub encroachment, yet the effect of this shift in species composition on litter decomposition remains unclear,...     

Rapid adaptive responses of rosette‐type macrophyte Vallisneria natans juveniles to varying water depths: The role of leaf trait plasticity

Rosette‐type submerged macrophytes are widely distributed across a range of water depths in shallow lakes and play a key role in maintaining ecosystem structures and functions. However, little is known about the rapid adaptive responses of such macrophytes to variations in water depth, especially at the juvenile stage. Here, we conducted a short‐term in situ mesocosm experiment, in which the juveniles of Vallisneria natans were exposed to a water depth gradient ranging from 20 to 360 cm. Twenty‐two leaf‐related traits were examined after 4 weeks of growth in a shallow lake. Most (18) traits of V. natans generally showed high plasticity in relation to water depth. Specifically, juveniles allocated more biomass to leaves and had higher specific leaf area, leaf length‐to‐width ratio, chlorophyll content, and carotenoids content in deep waters, displaying trait syndrome associated with high resource acquisition. In contrast, V. natans juveniles in shallow waters had higher leaf dry matter content, leaf soluble carbohydrate content, carotenoids per unit chlorophyll, and peroxidase activity, pertaining to resource conservation. Notably, underwater light intensity was found to be the key factor explaining the trait plasticity along the water depth gradient, and 1.30 mol photons m⁻² d⁻¹ (at 270 cm) could be the optimal irradiance level based on the total biomass of V. natans juveniles. The present study highlights the significance of leaf trait plasticity for rosette‐type macrophytes in response to variations in water depth and sheds new light on the differences between trade‐offs in deep‐ and shallow‐water areas.     

Novel perfluorodiphenylphosphinic acid lanthanide (Er or Er-Yb) complex with high NIR photoluminescence quantum yield

A perfluorodiphenylphosphinic acid lanthanide (Er or Er-Yb) complex is synthesized by a one-pot process from perfluorotriphenylphosphine oxide and lanthanide (Er or Er-Yb) chloride; the photoluminescence quantum efficiency reaches 0.98% for the erbium complex and 3.5% for the erbium-ytterbium complex, about 50 times and 175 times, respectively, higher than the usual erbium organic complexes with the hydrogen-containing ligands.     

Near-infrared luminescence properties of erbium complexes with the substituted phthalocyaninato ligands.

Two homoleptic bis(phthalocyaninato) erbium(III) complexes Er[Pc(beta-OR/R)4]2 and two half-sandwich phthalocyaninato erbium(III) complexes (acac)Er[Pc(beta-OR/R)4] (OR = 1-n-pentyloxy and R = tert-butyl) have been investigated. Then we studied the near-infrared luminescence properties of the compounds. When the phthalocyanine ligands were excited, half-sandwich phthalocyaninato erbium(III) complexes showed strong near-infrared luminescence at 1540 nm while homoleptic bis(phthalocyaninato) erbium(III) complexes showed no signals. The full width at half maximum (FWHM) centered at 1540 nm in the emission spectrum of the half-sandwich complexes in solution and in solid state are 67 nm and 78 nm respectively, which shows potential for optical-amplification applications. Erbium-doped standard polymethyl-methacrylate (PMMA) matrix which was synthesized has also displayed NIR emission.     

Short-term response of CO<Subscript>2</Subscript> emissions to various leaf litters: a case study from freshwater marshes of Northeast China

Soil organic carbon (SOC) mineralization is an important process of carbon (C) cycling and budgeting associated with litter decomposition in terrestrial ecosystems. Research on altered plant-derived C input on soil C stability due to climate change is controversial and there remains considerable uncertainty in predicting soil C dynamics with the techniques currently available. In this study, we conducted a laboratory incubation experiment to test the effects of single- and mixed-Deyeuxia angustifolia (DA) and Carex lasiocarpa (CL) leaf litter addition on cumulative marshland soil CO₂ emission under waterlogged and non-waterlogged conditions in Sanjiang Plain, Northeast China. Results showed that the cumulative CO₂ emissions were significantly increased after leaf litter addition in both water conditions, and that the effect was more pronounced for DA amendment than CL regardless of water condition. The cumulative CO₂ efflux differed considerably between water conditions after DA addition, whereas no significant differences were found after CL addition. Remarkably impact of leaf litter types on cumulative CO₂ evolution was observed overall, water condition and interactions between leaf litter types and water conditions had no significant effect on CO₂ emissions, however. There were no non-additive effects of individual leaf litter type on total CO₂ efflux of the mixed-leaf litter addition treatments. The results of this study indicate that plant litter input to the C-rich marshy soil can induce rapid changes in SOC decomposition regardless of water conditions and that plant residue effects should be taken into consideration when assessing the dynamics of wetland soil system to the future climate scenarios.