Seasonal changes in hydraulic functions of eight temperate tree species: divergent responses to freeze-thaw cycles in spring and autumn.

Freeze-thaw cycles (FTCs) are the major seasonal environment stress in the temperate and boreal forests, inducing hydraulic dysfunction and limiting tree growth and distribution. There are two types of FTCs in the field: FTCs with increasing temperature from winter to spring (spring FTCs); and FTCs with decreasing temperature from autumn to winter (autumn FTCs). While previous studies have evaluated the hydraulic function during the growing season, its seasonal changes and how it adapts to different types of FTCs remain unverified.

Elevated CO and nitrogen addition enhance the symbiosis and functions of rhizosphere microorganisms under cadmium exposure.

Soil microbes are fundamental to ecosystem health and productivity. How soil microbial communities are influenced by elevated atmospheric carbon dioxide (eCO) concentration and nitrogen (N) deposition under heavy metal pollution remains uncertain, despite global exposure of terrestrial ecosystems to eCO, high N deposition and heavy metal stress. Here, we conducted a four year's open-top chamber experiment to assess the effects of soil cadmium (Cd) treatment (10 kg hm year) alone and combined treatments of Cd with eCO concentration (700 ppm) and/or N addition (100 kg hm year) on tree growth and rhizosphere microbial community.

Nitrogen and phosphorus addition promote invasion success of invasive species via increased growth and nutrient accumulation under elevated CO2.

In the context of the resource allocation hypothesis regarding the trade-off between growth and defence, compared with native species, invasive species generally allocate more energy to growth and less energy to defence. However, it remains unclear how global change and nutrient enrichment will influence the competition between invasive species and co-occurring native species. Here, we tested whether nitrogen (N) and phosphorus (P) addition under elevated CO2 causes invasive species (Mikania micrantha and Chromolaena odorata) to produce greater biomass, higher growth-related compounds and lower defence-related compounds than native plants (Paederia scandens and Eupatorium chinense).

Contrasting responses in growth, photosynthesis and hydraulics of two subtropical tree species to cadmium contamination as affected by elevated CO and nitrogen addition.

Plant growth, photosynthesis, and hydraulics are affected by heavy metals but also by elevated atmospheric CO concentration (e[CO]) and nitrogen (N) deposition. However, few studies have investigated the response of woody species to the combined effects of these three factors. We conducted an open-top chamber experiment with two common subtropical trees (Acacia auriculiformis and Syzygium hainanense) to explore the effects of cadmium (Cd)-contamination, e[CO], and N addition on plant eco-physiological traits.

Effects of elevated CO2 concentration and nitrogen addition on the chemical compositions, construction cost and payback time of subtropical trees in Cd-contaminated mesocosm soil.

Rising atmospheric CO2 concentration ([CO2]) and nitrogen (N) deposition are changing plant growth, physiological characteristics and chemical compositions; however, few studies have explored such impacts in a heavy metal-contaminated environment. In this study, we conducted an open-top chamber experiment to explore the impacts of 2 years of elevated atmospheric [CO2] and N addition on the growth, physiological characteristics and chemical compositions of five subtropical tree species in a cadmium (Cd)-contaminated environment. Results showed that N addition significantly increased concentration of leaf N and protein in five tree species and also decreased payback time (PBT) and leaf carbon:nitrogen ratios and increased tree relative height growth rate (RGR-H) and basal diameter growth rate (RGR-B) in Liquidambar formosana Hance and Syzygium hainanense Chang et Miau.

Effects of elevated CO concentration and nitrogen addition on foliar phosphorus fractions of Mikania micranatha and Chromolaena odorata under low phosphorus availability.

Invasive plants rapidly spread in habitats with low soil phosphorus (P) availability and have triggered a sharp decline in the diversity of native species. However, no studies have explored how widespread invasive species acclimate to low soil P availability via changing foliar P fractions, especially under elevated atmospheric CO concentrations ([CO ]) and nitrogen (N) deposition. Here, an open-top chamber experiment was conducted to explore the effect of nutrient addition and elevated [CO ] on leaf traits and foliar functional P fractions (i.

Latitudinal patterns of terrestrial phosphorus limitation over the globe.

Phosphorus limitation on terrestrial plant growth is being incorporated into Earth system models. The global pattern of terrestrial phosphorus limitation, however, remains unstudied. Here, we examined the global-scale latitudinal pattern of terrestrial phosphorus limitation by analysing a total of 1068 observations of aboveground plant production response to phosphorus additions at 351 forest, grassland or tundra sites that are distributed globally.

Effects of plant growth regulator and chelating agent on the phytoextraction of heavy metals by Pfaffia glomerata and on the soil microbial community.

Pfaffia glomerata is a candidate for the remediation of heavy metal-contaminated soil, but phytoremediation efficiency requires enhancement. In this study, we evaluated how application of DA-6, EDTA, or CA affected the growth and heavy metal accumulation of P. glomerata and soil microorganisms.

Global meta-analysis shows pervasive phosphorus limitation of aboveground plant production in natural terrestrial ecosystems.

Phosphorus (P) limitation of aboveground plant production is usually assumed to occur in tropical regions but rarely elsewhere. Here we report that such P limitation is more widespread and much stronger than previously estimated. In our global meta-analysis, almost half (46.

Effects of forest conversion on carbon-degrading enzyme activities in subtropical China.

The mineralization of soil organic carbon (SOC) is primarily mediated by carbon (C) degrading enzyme. In the current study, we determined how the activities of four soil C-degrading enzymes, the hydrolases β-glucosidase (BG) and cellobiohydrolase (CBH) and the oxidases polyphenol oxidase (PPO) and peroxidase (POD), responded to forest conversion of natural broadleaf forests (BF) to secondary forests (SF) and plantation forests (PF) in subtropical China. We also quantified SOC, dissolved organic C (DOC), permanganate oxidase organic C (PXC), recalcitrant C (RC), microbial biomass C (MBC), mineral-associated C (MOC), soil particle-sizes distribution, pH, and moisture content, and C: nitrogen (N) ratio.

Effects of elevated atmospheric CO and nitrogen deposition on leaf litter and soil carbon degrading enzyme activities in a Cd-contaminated environment: A mesocosm study.

Rising atmospheric CO concentration and nitrogen (N) deposition are changing terrestrial carbon (C) cycle; however, little has been known about such impacts in a heavy-metal-contaminated environment. This study conducted an open-top chamber experiment to explore the impacts of rising atmospheric CO concentration and N deposition on the leaf litter and soil C cycle in cadmium (Cd)-contaminated environment. The experiment include five treatments: control, Cd (30 g ha yr) addition, Cd addition under elevated CO (700 ppm CO), Cd and N(100 kg ha yr) additions, and Cd and N additions under elevated CO, with three replicates per treatment.