Quantification of Soil Carbon in Ituri Forest, Dem. Rep. Congo · Democratic Republic of Congo....

Post on 22-May-2020

4 views 0 download

Transcript of Quantification of Soil Carbon in Ituri Forest, Dem. Rep. Congo · Democratic Republic of Congo....

Nsalambi V. Nkongolo, J-JK. Mbuyi, MW. LokondaInstitut Facultaire des Sciences Agronomiques

Promoting carbon sequestrationto offset atmospheric carbondioxide by offering some sort ofincentives via direct payments orcarbon credits is a current topicof interest. However, severalquestions arise such as:

What is the best way todetermine the quantity andquality of carbon in soils?

How much carbon can a soilsequester?

To address these questions,inventories of soil carbonconcentrations are needed forconstant monitoring of currentcarbon status and potential forsequestration.

METHODOLOGYThis study was conducted atLenda1 Forest Dynamics Plots(FDP) in the Okapi FaunalReserve (OFR), Ituri Forest,Democratic Republic of Congo.Lenda1 Forest Dynamics Plot islocated at the north of Lenda2, at1o 19' N latitude and 28o 38' Elongitude. Surface soil samples(0-10 cm depth) were collectedalong a 20 m x 20 m grid in the10 ha plot. A portable GPSreceiver was used to record thecoordinates of each samplinglocation. Soil samples were air-dried and brought to HarvardForest, Harvard University foranalysis of soil organic carbonand other nutrients. Soil organiccarbon density (SOCD) wascalculated according to Pluske,Murphy and Sheppard as shownbelow :

Scheme 1: I.e. 10,000 m2 in one hectarex 0.1 m soil depth x 1.4 g/cm3 bulkdensity x 1.2 % = 16.8t/ha.Source:http://www.soilquality.org.au/factsheets/organic-carbon

The objective of this study was toassess the status of soil carbonand other nutrients in IturiForest, Democratic Republic ofCongo.

Coefficient of variation (CV) forsoil bulk density (BDY) was lessthan 20%, suggesting that therewas less variability and that BDYwas well measured. Therefore,any effect of BDY inoverestimating soil organiccarbon (SOC) can be ruled out.The results of this preliminarystudy also showed the potentialfor soil carbon sequestration inthis 10 ha pristine forest plot,dominated by Gilbertiodendrondewevrei. SOC averaged 29.61tons /ha in the 0-10 cm layer inIturi Forest. This value seems tosuggest greater SOC storage inIturi Forest as compared tonearby forest of the same region.In fact, although they sampled indifferent forests and higher soillayer but in the same province,Doetterl et al. (2016) reportedSOC values of 23.10 Mg C/ha inYoko Forest and 55.70 Mg C/hain Yangambi Forest for the 0-30cm depth. Our results for a thirdof their sampling depth showshigher values of SOC.

It is suggested the study bepursued to include deeper soillayers (10-100 cm) for a betterassessment of soil organiccarbon in Ituri Forest,Democratic Republic of Congo.

.

Fig. 1: Sampling design in the 10ha plot at Lenda1, Forest Dynamic Plot, IturiForest

Fig. 2: Distribution of soil organic matter (OM) across the 10 ha plot

Fig. 3: Distribution of Soil Organic Carbon (SOC) across the 10 ha plot

Tab. 1: Summary of simple statistics for soil properties in the 10 ha plot, Lenda1, Ituri Forest

Fig. 4: Variogram model for Soil Organic Matter

Fig. 5: Variogram model for Soil Organic Carbon

Fig. 7: Okapi Faunal Reserve, Ituri Forest, Dem. Rep. Congo

Fig. 6: Location of Lenda et Edoro Forest Dynamic Plots, Ituri Forest, Dem. Rep. Congo

Fig. 8b: Post sampling in the 10 ha plot, Ituri Forest, Dem. Rep. Congo

Quantification of Soil Carbon in IturiForest, Dem. Rep. Congo

INTRODUCTION OBJECTIVES MAIN RESULTS

CONCLUSIONS

Fig. 8a: Soil sampling in the 10 ha plot, Ituri Forest, Dem. Rep. Congo