Required sample size for estimating soil respiration rates in large areas of two tropical forests and of two types of plantation in Malaysia

Tropical forests represent the largest store of terrestrial carbon (C) and are potentially vulnerable to climatic variations and human impact. However, the combined influence of temperature and precipitation on aboveground and belowground C cycling in tropical ecosystems is not well understood. To simulate the impact of climate (temperature and rainfall) on soil C heterotrophic respiration rates of moist tropical forests, we translocated soil cores among three elevations (100, 700 and 1540 m a.s.l.) representing a range in mean annual temperature of 10.9°C and in rainfall of 6840 mm. Initial soil C stocks in the top 30 cm along the gradient increased linearly with elevation from 6.13 kg C m–2 at 100 m a.s.l. to 10.66 kg C m–2 at 1540 m a.s.l. Respiration rates of translocated soil cores were measured every 3 weeks for 1 year and were fitted to different model functions taking into account soil temperature, soil moisture, mean annual temperature and total annual rainfall. Measured data could be best fitted to the model equation based on temperature alone. Furthermore, Akaike’s information criteria revealed that model functions taking into account the temperature range of the entire translocation gradient led to better estimates of respiration rates than functions solely based on the site-specific temperature range. Soil cores from the highest elevation revealed the largest temperature sensitivity (Q10 = 2.63), whereas these values decreased with decreasing elevation (Q10 = 2.00 at 100 m a.s.l.) or soil C stocks. We therefore conclude that increased temperatures will have the greatest impact on soil C stocks at higher elevations, and that best projections for future soil respiration rates of moist tropical forest soils can be achieved based on temperature alone and large soil cores exposed to temperatures above site-specific temperature regimes.

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Comparison of greenhouse gas fluxes from tropical forests and oil palm plantations on mineral soil

Biogeosciences ◽

10.5194/bg-18-1559-2021 ◽

2021 ◽

Vol 18 (5) ◽

pp. 1559-1575

Author(s):

Julia Drewer ◽

Melissa M. Leduning ◽

Robert I. Griffiths ◽

Tim Goodall ◽

Peter E. Levy ◽

...

Keyword(s):

Land Use ◽

Nitrous Oxide ◽

Soil Respiration ◽

Greenhouse Gas ◽

Tropical Forests ◽

Oil Palm ◽

Riparian Area ◽

Respiration Rates ◽

N2o Fluxes ◽

Ghg Fluxes

Abstract. In Southeast Asia, oil palm (OP) plantations have largely replaced tropical forests. The impact of this shift in land use on greenhouse gas (GHG) fluxes remains highly uncertain, mainly due to a relatively small pool of available data. The aim of this study is to quantify differences of nitrous oxide (N2O) and methane (CH4) fluxes as well as soil carbon dioxide (CO2) respiration rates from logged forests, oil palm plantations of different ages, and an adjacent small riparian area. Nitrous oxide fluxes are the focus of this study, as these emissions are expected to increase significantly due to the nitrogen (N) fertilizer application in the plantations. This study was conducted in the SAFE (Stability of Altered Forest Ecosystems) landscape in Malaysian Borneo (Sabah) with measurements every 2 months over a 2-year period. GHG fluxes were measured by static chambers together with key soil physicochemical parameters and microbial biodiversity. At all sites, N2O fluxes were spatially and temporally highly variable. On average the largest fluxes (incl. 95 % CI) were measured from OP plantations (45.1 (24.0–78.5) µg m−2 h−1 N2O-N), slightly smaller fluxes from the riparian area (29.4 (2.8–84.7) µg m−2 h−1 N2O-N), and the smallest fluxes from logged forests (16.0 (4.0–36.3) µg m−2 h−1 N2O-N). Methane fluxes were generally small (mean ± SD): −2.6 ± 17.2 µg CH4-C m−2 h−1 for OP and 1.3 ± 12.6 µg CH4-C m−2 h−1 for riparian, with the range of measured CH4 fluxes being largest in logged forests (2.2 ± 48.3 µg CH4-C m−2 h−1). Soil respiration rates were larger from riparian areas (157.7 ± 106 mg m−2 h−1 CO2-C) and logged forests (137.4 ± 95 mg m−2 h−1 CO2-C) than OP plantations (93.3 ± 70 mg m−2 h−1 CO2-C) as a result of larger amounts of decomposing leaf litter. Microbial communities were distinctly different between the different land-use types and sites. Bacterial communities were linked to soil pH, and fungal and eukaryotic communities were linked to land use. Despite measuring a large number of environmental parameters, mixed models could only explain up to 17 % of the variance of measured fluxes for N2O, 3 % of CH4, and 25 % of soil respiration. Scaling up measured N2O fluxes to Sabah using land areas for forest and OP resulted in emissions increasing from 7.6 Mt (95 % confidence interval, −3.0–22.3 Mt) yr−1 in 1973 to 11.4 Mt (0.2–28.6 Mt) yr−1 in 2015 due to the increasing area of forest converted to OP plantations over the last ∼ 40 years.

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Influence of fire on root biomass dynamics and soil respiration rates in young corsican pine (Pinus nigra) stands in Turkey

Forest Ecology and Management ◽

10.1016/j.foreco.2006.08.314 ◽

2006 ◽

Vol 234 ◽

pp. S195 ◽

Cited By ~ 1

Author(s):

Aydın Tüfekçioğlu ◽

Mehmet Küçük ◽

Bülent Sağlam ◽

Ertuğrul Bilgili ◽

Lokman Altun ◽

...

Keyword(s):

Soil Respiration ◽

Root Biomass ◽

Pinus Nigra ◽

Respiration Rates ◽

Biomass Dynamics

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SEASONAL CHANGES IN SOIL RESPIRATION RATES IN OLIVE ORCHARDS

Acta Horticulturae ◽

10.17660/actahortic.2014.1057.30 ◽

2014 ◽

pp. 275-280 ◽

Cited By ~ 3

Author(s):

C. Bertolla ◽

G. Caruso ◽

R. Gucci

Keyword(s):

Soil Respiration ◽

Seasonal Changes ◽

Respiration Rates

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Simulating short-term dynamics of non-increasing soil respiration rates by a model using Michaelis-Menten kinetics

Soil Science & Plant Nutrition ◽

10.1111/j.1747-0765.2010.00524.x ◽

2010 ◽

Vol 56 (6) ◽

pp. 874-882 ◽

Cited By ~ 1

Author(s):

Kozue SAWADA ◽

Shinya FUNAKAWA ◽

Takashi KOSAKI

Keyword(s):

Soil Respiration ◽

Short Term ◽

Respiration Rates

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Responses of soil respiration to elevated carbon dioxide and nitrogen addition in young subtropical forest ecosystems in China

Biogeosciences ◽

10.5194/bg-7-315-2010 ◽

2010 ◽

Vol 7 (1) ◽

pp. 315-328 ◽

Cited By ~ 84

Author(s):

Q. Deng ◽

G. Zhou ◽

J. Liu ◽

S. Liu ◽

H. Duan ◽

...

Keyword(s):

Soil Respiration ◽

Elevated Co2 ◽

Forest Ecosystems ◽

N Deposition ◽

Subtropical Forest ◽

N Addition ◽

Above Ground Biomass ◽

Respiration Rates ◽

Ambient Co2 ◽

Ambient N Deposition

Abstract. Global climate change in the real world always exhibits simultaneous changes in multiple factors. Prediction of ecosystem responses to multi-factor global changes in a future world strongly relies on our understanding of their interactions. However, it is still unclear how nitrogen (N) deposition and elevated atmospheric carbon dioxide concentration [CO2] would interactively influence forest floor soil respiration in subtropical China. We assessed the main and interactive effects of elevated [CO2] and N addition on soil respiration by growing tree seedlings in ten large open-top chambers under CO2 (ambient CO2 and 700 μmol mol−1) and nitrogen (ambient and 100 kg N ha−1 yr−1) treatments. Soil respiration, soil temperature and soil moisture were measured for 30 months, as well as above-ground biomass, root biomass and soil organic matter (SOM). Results showed that soil respiration displayed strong seasonal patterns with higher values observed in the wet season (April–September) and lower values in the dry season (October–March) in all treatments. Significant exponential relationships between soil respiration rates and soil temperatures, as well as significant linear relationships between soil respiration rates and soil moistures (below 15%) were found. Both CO2 and N treatments significantly affected soil respiration, and there was significant interaction between elevated [CO2] and N addition (p<0.001, p=0.003, and p=0.006, respectively). We also observed that the stimulatory effect of individual elevated [CO2] (about 29% increased) was maintained throughout the experimental period. The positive effect of N addition was found only in 2006 (8.17% increased), and then had been weakened over time. Their combined effect on soil respiration (about 50% increased) was greater than the impact of either one alone. Mean value of annual soil respiration was 5.32 ± 0.08, 4.54 ± 0.10, 3.56 ± 0.03 and 3.53 ± 0.03 kg CO2 m−2 yr−1 in the chambers exposed to elevated [CO2] and high N deposition (CN), elevated [CO2] and ambient N deposition (CC), ambient [CO2] and high N deposition (NN), and ambient [CO2] and ambient N deposition (CK as a control), respectively. Greater above-ground biomass and root biomass was obtained in the CN, CC and NN treatments, and higher soil organic matter was observed only in the CN treatment. In conclusion, the combined effect of elevated [CO2] and N addition on soil respiration was apparent interaction. They should be evaluated in combination in subtropical forest ecosystems in China where the atmospheric CO2 and N deposition have been increasing simultaneously and remarkably.

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Soil respiration rates and in natural beech forest (Fagus sylvaticaL.) in relation to stand structure

Isotopes in Environmental and Health Studies ◽

10.1080/10256016.2011.578214 ◽

2011 ◽

Vol 47 (2) ◽

pp. 221-237 ◽

Cited By ~ 11

Author(s):

Matjaž Čater ◽

Nives Ogrinc

Keyword(s):

Soil Respiration ◽

Stand Structure ◽

Beech Forest ◽

Respiration Rates

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Edaphic and environmental controls of soil respiration and related soil processes under two contrasting manuka and kanuka shrubland stands in North Island, New Zealand

Soil Research ◽

10.1071/sr12248 ◽

2013 ◽

Vol 51 (5) ◽

pp. 390 ◽

Cited By ~ 4

Author(s):

C. B. Hedley ◽

S. M. Lambie ◽

J. L. Dando

Keyword(s):

Nitrous Oxide ◽

New Zealand ◽

Soil Respiration ◽

Respiration Rate ◽

Nitrous Oxide Emissions ◽

Volcanic Soil ◽

Mineral N ◽

Organic C ◽

Respiration Rates ◽

Environmental Controls

The conversion of marginal pastoral land in New Zealand to higher biomass shrubland consisting of manuka (Leptospermum scoparium) and kanuka (Kunzea ericoides var. ericoides) offers opportunity for carbon (C) sequestration, with potential co-benefits of soil erosion control. We therefore selected two areas with different soils in different climatic regions to investigate and compare soil respiration rates, methane and nitrous oxide emission profiles, and key carbon exchange processes controlling carbon sequestration. In addition, two shrubland stands of different ages were selected in each area, providing four sites in total. Regular (almost monthly) soil respiration measurements were made over a 2-year period, with less frequent methane and nitrous oxide flux measurements, and soil sampling once at the end of the study. The cooler, wetter volcanic soils had higher total organic C (6.39 ± 0.12% v. 5.51 ± 0.17%), soil C : nitrogen (N) ratios (20.55 ± 0.20 v. 18.45 ± 0.23), and slightly lower mineral N (3.30 ± 0.74 v. 4.89 ± 0.57 mg/kg) and microbial biomass C (1131 ± 108 v. 1502 ± 37 mg/kg) than the more drought-prone, stony, sedimentary soils. Mineral-N contents at all sites indicated N-limited ecosystems for allocation of below- and above-ground C. The estimated mean annual cumulative respiration rate recorded in the volcanic soil was 10.26 ± 7.45 t CO2-C/ha.year compared with 9.85 ± 8.63 t CO2-C/ha.year in the stony sedimentary soil for the 2 years of our study. Older shrubland stands had higher respiration rates than younger stands in both study areas. Methane oxidation was estimated to be higher in the volcanic soil (4.10 ± 2.13 kg CH4-C/ha.year) than the sedimentary soil sites (2.51 ± 2.48 kg CH4-C/ha.year). The measured natural background levels of nitrous oxide emissions from these shrubland soils ranged between negligible and 0.30 ± 0.20 kg N2O-N/ha.year. A strong climatic control (temperature and moisture) on gas fluxes was observed at all sites. Our sampling strategy at each of the four sites was to estimate the mean soil respiration rates (n = 25) from an 8 by 8 m sampling grid positioned into a representative location. Soil respiration rates were also measured (by additional, less frequent sampling) in two adjacent grids (1-m offset and 100-m distant grid) to test the validity of these representative mean values. The 1-m offset grid (n = 25) provided a statistically different soil respiration rate from the main grid (n = 25) in 25% of the 12 sampling events. The 100-m grid (n = 25) provided a statistically different respiration rate to the main grid in 38% of the 26 sampling events. These differences are attributed to the spatially variable and sporadic nature of gaseous emissions from soils. The grid analysis tested the prediction uncertainty and it provides evidence for strong spatial and temporal control by edaphic processes in micro-sites. A partial least-squares regression model was used to relate the 2009 annual cumulative soil respiration to site-specific edaphic characteristics, i.e. biomass, nutrient availability, porosity and bulk density, measured at the end of that year. The model explained ≥80% of the variance at three of the four sites.

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