Day and night respiration of three tree species in a temperate forest of northeastern China

Abstract

© iForest -Biogeosciences and Forestry IntroductionDark respiration (non-photorespiratory respiration), which occurs both in light and in darkness, has a critical function in modulating the carbon balance of plants and terrestrial ecosystems. Ryan (1991) showed that the proportion of carbon consumption by respiration is nearly 70% of the total photosynthetic carbon fixation, and leaf respiration accounts for approximately 50% of total plant respiration (Poorter et al. 1991). At the ecosystem level, CO2 emission from plant respiration accounts for 30-70% of the total ecosystem CO2 exchange (Amthor 2000). Plant respiration releases 60 Gt C yr -1 into the atmosphere (Schimel 1995). Therefore, understanding the carbon cycle of terrestrial ecosystems requires a more thorough understanding of the characteristics of leaf respiration.Due to difficulty in directly measuring leaf day respiration (RL), it is often assumed to be equal to night respiration (Poorter et al. 1990, Collier et al. 1992. However, Kok (1948) found that net CO2 assimilation rate (An) rapidly decreased near the light compensation point, leading to the conclusion that leaf respiration may vary with light intensity. Indeed, McCashin et al. (1988) found that 14 CO2 production during tricarboxylic acid cycle is approximately 20% lower in light than in darkness, which indicates that day respiration is inhibited in light. Subsequent studies confirmed that day respiration rates are lower than night respiration rates. Using stable 12 C/ 13 C isotope techniques, Tcherkez et al. (2005) found that two main processes (glycolysis and the Krebs cycle) of day respiration are strongly inhibited in illuminated leaves of French bean. Thus, plant respiration in light is overestimated if RL is assessed using data obtained during nighttime (Graham 1980, Sharp et al. 1984, Kirschbaum & Farquhar 1987, Kromer 1995, Atkin et al. 1997, Hoefnagel et al. 1998, Ayub et al. 2011.Plant respiration is a critical component of the gross primary production (GPP). Therefore, it is important to take into account the inhibitory effect of light on leaf respiration in order to obtain sound estimates of GPP. Wohlfahrt et al. (2005) estimated a reduction of 11-17% in GPP due to light inhibition in a mountain meadow, as compared to GPP model based on night respiration. Janssens et al. (2001) proposed that assessing day respiration by extrapolating night respiration results in an overestimation of ~15% of the total ecosystem respiration. Bruhn et al. (2011) recently reported that GPP estimation after taking into account light inhibition on leaf respiration for the average day is 76% of the GPP estimation taken without consideration of reduction in leaf respiration due to illumination. Thus, accurate estimates of the GPP requires the inhibition of leaf dark respiration by light to be considered.The Kok and Laisk methods are the two main methods used to estimate leaf day respiration. Kok (1948) analyzed the response of net photosynthesis rate to low light intensities and showed that the slope ...

Effects of nitrogen additions on mesophyll and stomatal conductance in Manchurian ash and Mongolian oak

“…In theory, three CO 2 response curves obtained by varying CO 2 concentrations from 150 to 40 µmol CO 2 mol −1 under three PPFDs (150, 100 and 50 µmol m −2 s −1 ) would intersect with each other at a point, and the intersection point at x-axis and y-axis were considered to Г * and R d , respectively. But in practice, these three linear regressions of the intersected A n -C i curves formed a triangle range rather than a single point 40 (Fig. S1), and the Г * and R d were calculated as the barycenter of the triangle formed by the intersection of the three lines at x-axis and y-axis, respectively, according to our previous published method 40 .…”

“…But in practice, these three linear regressions of the intersected A n -C i curves formed a triangle range rather than a single point 40 (Fig. S1), and the Г * and R d were calculated as the barycenter of the triangle formed by the intersection of the three lines at x-axis and y-axis, respectively, according to our previous published method 40 . The values of Г * and R d during soil nitrogen additions were shown in Table S2.…”

Colonization of a Deglaciated Moraine: Contrasting Patterns of Carbon Uptake and Release from C3 and CAM Plants

“…To partition NEE fluxes into the originating R eco and GEE fluxes, night time NEE data are generally used to extrapolate R eco during the day by adopting a temperature response function [50], although it has been suggested that this method may lead to an overestimation of R eco [61]. Alternatively, the light response curve estimated during daytime is used, and the respiration is obtained from the intercept on the ordinate [62].…”

Effects of environmental factors on the temporal and spatial variations in branch and leaf CO2 efflux of Larix gmelinii var. principis-rupprechtii Mayr

“…However, light can inhibit plant respiration (Parnik et al 2010;Ayub et al 2014). For example, Sun et al (2015) found that daily respiration decreased with increasing photosynthetic photon flux density, and a small amount of light can also inhibit respiration. However, Wang and Mao (2007) suggested that light was not the main factor affecting respiration.…”