Seasonal changes in the contribution of root respiration to total soil respiration in a cool-temperate deciduous forest

Abstract

A trenching method was used to determine the contribution of root respiration to soil respiration. Soil respiration rates in a trenched plot (Rtrench) and in a control plot (Rcontroi) were measured from May 2000 to September 2001by using an open-flow gas exchange system with an infrared gas analyser. The decomposition rate of dead roots (Ro) was estimated by using a root-bag method to correct the soil respiration measured from the trenched plots for the additional decaying root biomass. The soil respiration rates in the control plot increased from May (240-320 mg C02 m-2 h-1 ) to August (840-1150 mg C02 m-2 h-i ) and then decreased during autumn (200-650 mg C02 m-2 h-1 ). The soil respiration rates in the trenched plot showed a similar pattern of seasonal change, but the rates were lower than in the control plot except during the 2 months following the trenching. Root respiration rate (Rr) and heterotrophic respiration rate (Rh) were estimated from Rcontrol, Rtrench, and Ro. We estimated that the contribution of Rr to total soil respiration in the growing season ranged from 27 to 71 %. There was a significant relationship between Rh and soil temperature, whereas Rr had no significant correlation with soil temperature. The results suggest that the factors controlling the seasonal change of respiration differ between the two components of soil respiration, Rr and Rh.Abbreviations: Ro -carbon emission due to the decomposition of residual roots; Rh -heterotrophic respiration rate; Rr -root respiration rate; NEP -net ecosystem production; NPP -net primary productivity

Topographic variation in heterotrophic and autotrophic soil respiration in a tropical seasonal forest in Thailand

“…Although there are methodological difficulties in separating respiration sources (Hanson et al 2000;Subke et al 2006), one practical method to estimate root respiration is to dig a trench around the respiration monitoring chamber in order to exclude root respiration from the soil (Katagiri 1988;Lee et al 2003;Sulzman et al 2005;Vogel et al 2005, Wang et al 2006Schaefer et al 2009). The root trenching method in particular is often used in the forest ecosystem because of its high applicability to remote areas despite criticisms that disturbance by trenching affects root decomposition, soil moisture, and the soil microbial community (Hanson et al 2000;Kuzyakov and Larionova 2005).…”

Soil Respiration in Different Ages of Teak Plantations in Thailand

“…However, soil carbon dynamics should also be identified because changes in soil carbon stock, which is the biggest carbon pool in the terrestrial ecosystem, might significantly affect CO 2 concentration 9,11,13 . Therefore, soil respiration, i.e., CO 2 flux from the forest floor, is a key parameter for determining carbon balance in the forest ecosystem 14 . For plantation forestry, teak (Tectona grandis) is a popular species in tropical countries 12 .…”

“…Soil respiration is composed of heterotrophic respiration by soil biota and autotrophic respiration by roots. Separation of heterotrophic and autotrophic respiration is important for evaluating carbon balance in the soil 5,14,18 . Contribution of root respiration to total respiration was reviewed and found to range from 10 to 90%, although there are methodological difficulties in measuring root respira-tion in the field 6 .…”

“…Contribution of root respiration to total respiration was reviewed and found to range from 10 to 90%, although there are methodological difficulties in measuring root respira-tion in the field 6 . One common method for estimating root respiration is to make a trench to exclude roots around the chamber 14,24 , although there is a possibility that trenching will produce some artificial effects on root decomposition and soil moisture.…”

Fluctuations in the properties of forest soils in the Central European highlands (Czech Republic)

“…Short-term soil development observations were extrapolated using approximated periodic functions of the medium-term soil property behaviour. The nature of the relationship among some of the soil parameters is that of an exponential function (Lee et al 2003) but in longer time periods they are subject to cyclic oscillations (Heuvelink & Webster 2001). Degradation of forest soils was most influenced by erosion after deforestation, acid deposits, and repeated cultivation of monocultures (Evans et al 2001;Klimo et al 2006;Oulehle et al 2010).…”