Kamal Shaltout & Ebrahem Eid

Transcription

1 Kamal Shaltout & Ebrahem Eid Botany Department, Faculty of Science, Tanta University Botany Department, Faculty of Science, Kafr El-Sheikh University 1

2 Concentration of CO 2 has increased from 280 ppmv in 1850 to 380 ppmv in 2005 (31%). Now, it is increasing at a rate of 1.7 ppmv year 1. With CO 2 increase, there is growing public and scientific concern about the carbon sequestration potential (CSP) of various terrestrial ecosystems especially wetlands. 2

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5 Many scientists have suggested that the sequestration of atmospheric CO 2 into soil organic carbon (SOC) could contribute significantly to adhere with Kyoto Protocol to reduce emissions of greenhouse gases for mitigating the risks of global warming. 5

6 Kyoto Protocol was adopted in Kyoto, Japan, on 11 December Due to a complex ratification process, it entered into force on 16 February It is an international treaty that sets binding obligations on industrialized countries to reduce emissions of greenhouse gases. 6

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8 There are three strategies of lowering CO 2 emissions (Schrag (2007): 1- Reducing the global energy use, 2- Developing low or no-carbon fuel, 3- Sequestering CO 2 from point sources or atmosphere through natural and engineering techniques. Schrag DP (2007). Preparing to capture carbon. Science 315,

9 Fifteen options for the stabilizing of the atmospheric CO 2 concentration by 2050 were outlined (Pacala and Socolow 2004); 3 of these were based on carbon sequestration in terrestrial ecosystems. Pacala S. & Socolow R (2004). Stabilization wedges: solving the climate problem for the next 50 years with current technologies. Science 305,

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11 Fig. 1. Map of Lake Burullus (Egypt) indicating the locations of the six sampling stations (*). 11

12 Open water of Lake Burullus 12

13 Phragmites australis stands 13

14 The objectives of the present study to assess the distribution of soil organic carbon in vegetated and un-vegetated sites in Lake Burullus, Egypt; to give accurate estimation of soil organic carbon stock in this lake in order to meet the requirements of the Kyoto Protocol; and to provide estimates of its carbon sequestration potential. 14

15 Six sampling locations Vegetated and unvegetated sites Five soil cores per site Soil cores were immediately sectioned with a blade into samples each of 10 cm thick (0 10, 10 20, and cm) July 2011 Experimental design Each soil sample was oven-dried at 105 C for three days Loss-on-ignition method at 550 C for two hours 15

16 During sampling 16

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19 Determination of soil bulk density 1- Soil bulk density (g cm 3 ): where ρ sj is SBD (g cm 3 ) of the j th horizon, m j is mass of soil sample (g) of the j th horizon dried at 105 C and v j is volume of soil sample (cm 3 ) of the j th horizon. 19

20 Determination of soil organic carbon content 2- Each sample was analyzed for SOC content by: measuring soil organic matter (SOM) using loss-on-ignition method at 550 C for two hours as follows: SOC (g C kg 1 ) = 0.58 SOM (g C kg 1 ) 20

21 Caculation of soil organic carbon density 3- SOC density (kg C m 3 ): SOC dj = ρ sj SOC j where SOC dj is SOC density (kg C m 3 ) of j th horizon, ρ sj is SBD (g cm 3 ) of the j th horizon, SOC j is SOC content (g C kg 1 ) of the j th horizon. 21

22 Calculation of soil organic carbon mass 4- SOC mass per unit surface area (kg C m 2 ): where SOC m is SOC mass per unit surface area (kg C m 2 ), D r is reference depth (= 0.4 m), T j is thickness (m) of the j th horizon and k is number of the horizons (= 4). 22

23 Introduction Study area Results Conclusions Recommendations Calcualtion of total soil organic carbon stock 5- Total SOC stock (Gg C = 10 6 kg C) in Lake Burullus: where SOC t is the total SOC stock (Gg C) in the study area, SOC mi is SOC mass per unit surface area (kg C m 2 ) in the i th class, A i is area (m 2 ) of the i th class and n is number of the classes (= 2: vegetated and un-vegetated). 23

24 Introduction Study area Methods Results Conclusions Calculation of carbon sequestraion rate (CSR) 6- CSR (g C m 2 year 1 ): where CSR i is CSR (g C m 2 year 1 ) of the i th class, ρ i is the mean soil bulk density (g cm 3 ) of the i th class, SOC i is mean SOC content (%) of the i th class and R is the sedimentation rate in the lake of 4.7 mm year 1 (see Shaltout Khalil 2005). 24

25 Calculation of carbon sequestraion potential (CSP) 7- CSP (Gg C year 1 ): where CSP i is CSP (Gg C year 1 ) of the i th class and A i is area (m 2 ) of the i th class. 25

26 Statistics ANOVA: Differences between sites over soil depth. Least significant difference (LSD): Significant differences between means among the four soil depths were identified using LSD test at P < Regression: relation between SOC content and soil bulk density. 26

27 Fig. 2. Mean distribution of soil bulk density (g cm 3 ) with soil depth (cm) in vegetated and un-vegetated sites of Lake Burullus. Horizontal bars indicate the standard errors of the means (N = 30). 27

28 Fig. 3. Mean distribution of soil organic carbon content (g C kg 1) with soil depth (cm) in vegetated and un-vegetated sites of Lake Burullus. Horizontal bars indicate the standard errors of the means (N = 30). 28

29 The relationship between soil bulk density (g cm 3 ) and SOC content (g C kg 1 ) for soils of Lake Burullus: Soil bulk density = SOC R 2 = 0.31 (P < 0.001) 29

30 Fig. 4. Mean distribution of soil organic carbon density (kg C m 3) with soil depth (cm) in vegetated and un-vegetated sites of Lake Burullus. Horizontal bars indicate the standard errors of the means (N = 30). 30

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32 5- Total SOC storage in the upper 40 cm in the Egyptian Northern lakes is Gg C (Gg=10 6 kg): Lake Area (km 2 ) SOC Storage (Gg C) Lake Bardawil Lake Burullus Lake Edku Lake Mariut Gg C Lake Manzala 1020 km 2 Lake Manzala Total

33 1- It is necessary to protect and restore these wetland ecosystems for carbon sequestration potential, as well as other ecosystem services. 2- More research is needed for the better understanding of the impact of environmental factors such as water pollution water level fluctuations, ph, temperature and precipitation on CSR. 34

34 3- Recent research is required for understanding the role of vegetation in sequestering the organic carbon in their tissues, particularly the under ground parts (green carbon storage), and to evaluate the impact of the variable nutrient regimes and loading rates on the different plant species. 35

35 Thanks for your attention 36