Do tree species characteristics influence soil respiration in tropical forests? A test based on 16 tree species planted in monospecific plots

Abstract

The high spatial variability of soil respiration in tropical rainforests is well evaluated, but influences of biotic factors are not clearly understood. This study underlines the influence of tree species characteristics on soil respiration across a 16-monospecific plot design in a tropical plantation of French Guiana. A large variability of soil CO2 fluxes was observed among plots (i.e. 2.8 to 6.8 μmol m−2 s −1 ) with the ranking being constant across seasons. There were no significant relationships between soil respiration and soil moisture or soil temperature, neither spatially, nor seasonally. The variability of soil respiration was mainly explained by quantitative factors such as leaf litterfall and basal area. Surprisingly, no significant relationship was observed between soil respiration and root biomass. However, the influence of substrate quality was revealed by a strong relationship between soil respiration and litterfall P (and litterfall N, to a lesser extent)

Long-term presence of tree species but not chemical diversity affect litter mixture effects on decomposition in a neotropical rainforest

“…According to the patch-scale process of litter decomposition, individual microcosms were considered as independent replicates just as in most litterbag studies. Moreover, previous studies in the plantation (Bréchet et al 2009) and in the nearby natural forest (Hättenschwiler and Bracht Jørgensen 2010;Fanin et al 2011) showed substantial variation in soil processes and decomposition at very small spatial scales that was as large or larger within blocks at the Oecologia (2011) 167:241-252 243 meter scale than among blocks of hundreds of meters distance (Fanin et al 2011).…”

“…Soils are nutrient-poor acrisol developed on a Precambrian metamorphic formation called the Bonidoro series. Soil characteristics are broadly the same in the plantation (Roy et al 2005;Bréchet et al 2009) and the natural forest (Hättenschwiler and Bracht Jørgensen 2010) with a similar texture, and similar concentrations of carbon (16.2 and 18.7 g C/kg in the plantation and the natural forest, respectively), nitrogen (1 and 1.2 g N/kg), and phosphorus (0.006 and 0.0055 g ''Olson P''/kg). The tree canopy in the plantation is somewhat more open (mean leaf area index of about 4; Roy et al 2005) than in the natural forest (leaf area index of about 6; Handa et al, unpublished data).…”

Automatic high-frequency measurements of full soil greenhouse gas fluxes in a tropical forest

“…Each week, four out of sixteen chambers were programmed to stay closed for a longer measurement period to ensure a reliable estimation of low fluxes while the other twelve chambers were 20 programmed to stay closed for a shorter period to capture diel variation and detect high fluxes. For the short closure time (SHORT hereafter), we used a 2 minute measurement period because (1) this is a standard closure time for soil CO2 flux calculations (Janssens et al, 2000), even in tropical forests (Epron et al, 2006;Sayer et al, 2007) of this region where MDF for CO2 flux is typically low (Bonal et al, 2008;Bréchet et al, 2009;Courtois et al, 2018), (2) ) are compatible with the detection of emission or consumption peaks of these 25 two gases in this region (Courtois et al, 2018;Petitjean et al, 2015). For the long closure time (LONG hereafter), we decided to use a 25 minute measurement period in order to optimize the trade-off between a reliable estimation of low N2O fluxes (Table 1) and a program length that allows for a sufficient number of flux measurements per chamber and per day.…”

Soil organic carbon stocks and CO2 effluxes of native and exotic pine plantations in subtropical China

“…Wang et al, 2013), and tropical rainforests (Bréchet et al, 2009). In our study, despite similar T s and SWC, R s of the native MP was 24% higher than the exotic SP.…”