BayCEER Workshop 2016
October 13, 2016
NW III, University of Bayreuth
Determining the Role of Agro-Ecosystems in a Changing Climate: Quantification of CO2 exchange, Carbon allocation and Storage in the Main Agricultural Crops of South Korea.
2 Chonnam National University,
O 4.1 in Land-use effects on ecosystems
13.10.2016, 12:00-12:15, H36, NW III
In most parts of the world, e.g. in Asia, the agricultural landscapes are characterized by complex, multicultural cropping systems that demand novel approaches to quantify C balances of the resulting croplands.
The use of portable chambers in this study, allowed direct measurements of net ecosystem exchange (NEE) of CO2, ecosystem respiration (Reco) and the evaluation of gross primary productivity (GPP) at small spatial scales (plot level), making it possible to key out functional differences of the 5 dominant crops (rice, potato, radish, cabbage and bean) in the Haean catchment, S. Korea, which is a model Asian agricultural landscape.
In this multicultural agroecosystem, the pattern and magnitudes of biomass and LAI development differed among the major crops likely as a result of differences in planting time, light use efficiencies (α) and carbon allocation patterns. Variations in seasonal patterns, magnitudes and the timing of maximum NEE and GPP among the crops were the result of differences in LAI and α, while photosynthetic active radiation (PAR) explained more than 90% of the diurnal variations in GPP.
The crop production system also influenced C storage by an agroecosystem. Although the patterns of CO2 uptake and LAI development were similar between flooded and rainfed rice, the PR system, was less efficient in nutrient use. Overall, N input significantly influenced plant productivity, LAI development, C partitioning and leaf- and ecosystem level CO2.
The study demonstrated that the active period of atmospheric C uptake is extended in multicultural, agroecosystem landscape due to the staggered timing of maximum CO2 uptake among crops, thus offering an ecological advantage by prolonging the period of high CO2 uptake. Flooding agriculture (paddy) offered no economic and the fact that paddy rice had lower leaf N than rainfed rice suggests that some of the N in PR might have been lost into the atmosphere or seeped underground and could be a source of environmental pollution.
Keywords: Agricultural landscapes Ecosystem CO2 exchange, Closed-chamber technique, Crop productivity, Biomass development, Nitrogen,
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