Simulated nitrogen deposition promotes the carbon assimilation of shrubs rather than tree species in an evergreen broad-leaved forest.

Although understory addition of nitrogen (UAN) is commonly used to simulate nitrogen deposition in field studies in forest ecosystems, it ignores the effects of atmospheric nitrogen deposition on the canopy. We studied the effects of nitrogen deposition simulated by UAN and by canopy addition of nitrogen (CAN) on leaf structure, chemical properties, Calvin cycle, and photosynthate distribution strategy of representative woody plant species in a subtropical evergreen broadleaved forest in South China. The results showed that maximum photosynthetic rate (A) of shrub species Blastus cochinchinensis and Ardisia quinquegona under CAN treatments was significantly higher than that of UAN treatments at the same N addition concentration.

Leaf hydraulic acclimation to nitrogen addition of two dominant tree species in a subtropical forest.

Plant hydraulic traits have been shown to be sensitive to changes in nitrogen (N) availability in short-term studies largely using seedlings or saplings. The extent and the magnitude of N-sensitivity of the field grown mature trees in long-term experiments, however, are relatively unknown. Here, we investigated responses of leaf water relations and morphological and anatomical traits of two dominant tree species (Castanopsis chinensis and Schima superba) to a six-year canopy N addition in a subtropical forest.

Global response patterns of plant photosynthesis to nitrogen addition: A meta-analysis.

A mechanistic understanding of plant photosynthetic response is needed to reliably predict changes in terrestrial carbon (C) gain under conditions of chronically elevated atmospheric nitrogen (N) deposition. Here, using 2,683 observations from 240 journal articles, we conducted a global meta-analysis to reveal effects of N addition on 14 photosynthesis-related traits and affecting moderators. We found that across 320 terrestrial plant species, leaf N was enhanced comparably on mass basis (N , +18.

Coordinated responses of plant hydraulic architecture with the reduction of stomatal conductance under elevated CO2 concentration.

Stomatal conductance (gs) generally decreases under elevated CO2 concentration (eCO2) and its sensitivity varies widely among species, yet the underlying mechanisms for these observed patterns are not totally clear. Understanding these underlying mechanisms, however, is critical for addressing problems regarding plant-environment interactions in a changing climate. We examined gs, water transport efficiency of different components along the whole-plant hydraulic system and allometric scaling in seedlings of six tree species grown under ambient and eCO2 treatments (400 and 600 ppm, respectively).

Nitrogen deposition potentially contributes to oak regeneration failure in the Midwestern temperate forests of the USA.

We conducted a 7-year field study at two oak-dominated forest sites which differ in their atmospheric N deposition to test the hypothesis that red oak regeneration failure in the upper Midwestern US forests, at least in part, results from increased N load. The sites are located in Swallow Cliffs (SC) in Cook County, Illinois, and Indiana Dunes National Lakeshore (IDNL) in Porter County, Indiana. Annual wet NO3(-) deposition for the 22 years immediately prior to the experiments was significantly higher in IDNL than in the SC site.

Effects of high atmospheric CO2 concentration on root hydraulic conductivity of conifers depend on species identity and inorganic nitrogen source.

We examined root hydraulic conductivity (L(p)) responses of one-year-old seedlings of four conifers to the combined effects of elevated CO2 and inorganic nitrogen (N) sources. We found marked interspecific differences in L(p) responses to high CO2 ranging from a 37% increase in P. abies to a 27% decrease in P.

Allocating nitrogen away from a herbivore: a novel compensatory response to root herbivory.

Centaurea maculosa, an invasive North American plant species, shows a high degree of tolerance to the root-boring biocontrol herbivore, Agapeta zoegana. For example, infested individuals of C. maculosa often exhibit more rigorous growth and reproduction compared with their non-infested counterparts.

Extreme events as shaping physiology, ecology, and evolution of plants: toward a unified definition and evaluation of their consequences.

Here we consider how extreme events, particularly climatic and biotic, affect the physiology, development, ecology and evolution of organisms, focusing on plants. The marked effects on organisms are of increasing interest for ecological prediction, given the natural and anthropogenic changes in spectra of extreme events being induced by global change. Yet there is currently a paucity of knowledge or even a common world-view of how extreme events shape individuals, communities and ecosystems.

Differential responses of tallgrass prairie species to nitrogen loading and varying ratios of NO3- to NH4.

Worldwide atmospheric N deposition varies in both quantity and composition of inorganic N forms (NO3 and NH4). Many studies designed to assess the potential consequences of N pollution, however, pay little attention to the relative abundance of N forms. We hypothesized that native species with different physiological properties will show varying responses to different forms and amounts of N deposition.

Root system adjustments: regulation of plant nutrient uptake and growth responses to elevated CO.

Nutrients such as nitrogen (N) and phosphorus (P) often limit plant growth rate and production in natural and agricultural ecosystems. Limited availability of these nutrients is also a major factor influencing long-term plant and ecosystem responses to rising atmospheric CO levels, i.e.

Effects of soil temperature and nitrogen status on kinetics of NO uptake by roots of field-grown Agropyron desertorum (Fisch. ex Link) Schult.

Plant NO - acquisition is largely determined by root uptake capacity. Although root uptake capacity has been shown to be sensitive to both root temperature and previous nitrogen (N) supply in hydroponic systems, the uptake capacity response to similar environmental factors under field conditions has not been investigated. Using NO , root uptake capacities were determined in excised roots of Agropyron desertorum (Fisch.