introduction the importance of soil respiration (sr) in the whole ecosystem functioning has
DESCRIPTION
The role of soil respiration in the carbon balance of a semiarid ecosystem in the South East of Spain João Raimundo 1 , Ana Rey 1 , Cecilio Oyonarte 2 1 Estación Experimental de Zonas Áridas, 2 Universidad de Almería. Introduction - PowerPoint PPT PresentationTRANSCRIPT
The role of soil respiration in the carbon balance of a semiarid ecosystem in the South East of Spain
João Raimundo1, Ana Rey1, Cecilio Oyonarte2
1 Estación Experimental de Zonas Áridas, 2 Universidad de Almería
IntroductionThe importance of Soil Respiration (SR) in the whole ecosystem functioning has been widely recognised. Semiarid ecosystems are poorly studied and thus not well understood. Other factors that so far have not been taken into account may play an important role in determining SR in semiarid ecosystems characterised by high temporal and spatial variability as well as high temperatures and low water availability.
IntroductionThe importance of Soil Respiration (SR) in the whole ecosystem functioning has been widely recognised. Semiarid ecosystems are poorly studied and thus not well understood. Other factors that so far have not been taken into account may play an important role in determining SR in semiarid ecosystems characterised by high temporal and spatial variability as well as high temperatures and low water availability.
3000Annual sun hours
Calcaric leptosolSoil type
Mediterranean steppe alpha grass (Stippa tenacissima L.)
Vegetation
200 mmAnnual mean precipitation
72%Annual relative humidity
18 ºCMean annual temperature
205 m asl (BB), 50 m asl (AM)
Altitude
N 36º56’26.0’’; W 2º01’58.8’’
Latitude
Dry Subtropical desert(semiarid)
Climate
Cabo de Gata Natural Park, Almería
Location
Study Field SitesBalsa Blanca – BBAmoladeras - AM
3000Annual sun hours
Calcaric leptosolSoil type
Mediterranean steppe alpha grass (Stippa tenacissima L.)
Vegetation
200 mmAnnual mean precipitation
72%Annual relative humidity
18 ºCMean annual temperature
205 m asl (BB), 50 m asl (AM)
Altitude
N 36º56’26.0’’; W 2º01’58.8’’
Latitude
Dry Subtropical desert(semiarid)
Climate
Cabo de Gata Natural Park, Almería
Location
Study Field SitesBalsa Blanca – BBAmoladeras - AM
(AM) (BB)
MethodologySR is being measured with a portable CO2 EGM-4 Gas Analyser and RS SRC-1 Chamber (PP-System, UK) in two field study sites (Balsa Blanca – Pristine and Amoladeras – Land Degradation).Soil temperature and soil moisture are measured at the same points.Six plots of 10 x 10 m were set up (n=6) and in each plot three replicates of soil collars were placed in three different soil covers: E (Under plant) C (Biologic crust) S (Bare soil)
Plot 66.2
10 m
5 m
5 m10 m
Plot 1
Plot 5
Plot 4
4.1
4.2
4.3
5.1
5.2
5.3
6.1
1.1
6.3
1.2
1.3
Plot 22.2
2.3
2.1
Plot 3
3.1
3.3
3.2
5 m
CENTER OF THE PLOT
REPLICATES
BIOLOGIC CRUST (C)
BARE SOIL (S)
UNDER PLANT (E)
Plot 66.2
10 m
5 m
5 m10 m
Plot 1
Plot 5
Plot 4
4.1
4.2
4.3
5.1
5.2
5.3
6.1
1.1
6.3
1.2
1.3
Plot 22.2
2.3
2.1
Plot 3
3.1
3.3
3.2
5 m
CENTER OF THE PLOT
REPLICATES
BIOLOGIC CRUST (C)
BARE SOIL (S)
UNDER PLANT (E)
Under Plant
Biologic Crust
Bare Soil
Replicate
Replicated in both BB and AM sites
www.climatescience.gov
Experimental design
Workshop, 5-9 September 2008, Technical University of Crete, Chania, Crete 3rd
Temporal and Spatial Variability
SR measured on Plot 2 from BB during 14 h
SR measured in BB and AM every week (every fortnight in Summer):-Diurnal Variation; Seasonal Variation; Interannual Variability.-SR variability between soil covers (E,C and S)
DIURNAL VARIABILITYBalsa Blanca
0.000.200.400.600.801.001.201.401.601.80
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Time of the Day (h)
SR
Rat
e
(µm
ol m
-2 s
-1)
Under Plant Biologic Crust Bare Soil
30/05/2008
TEMPORAL VARIABILITY Amoladeras
00.5
11.5
22.5
33.5
4
Soil R
espir
atio
n R
ate
(µm
ol m-2
s-1)
Spring Summer
Balsa Blanca
00.5
11.5
22.5
33.5
4
113 119 129 133 141 155 165 178 190 205 214 229
Julian Day
Soil R
espir
atio
n R
ate
(µm
ol m-2
s-1)
Under Plant Biologic Crust Bare Soil
Spring Summer
Land Degradation
0.712
1.081
0.760
1.211
0.710
1.110
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
Mea
n So
il R
espi
ration
(µm
ol m-2
s-1)
Under Plant Bilogic Crust Bare Soil
LAND DEGRADATION
Land Degradation (AM) Pristine (BB)
SR measured in two field sites every week (every fortnight in Summer):- Amoladeras (Land degradation)- Balsa Blanca (Pristine)
SR measurements after every rainfall events.
05
1015202530354045
Julian Day
Pre
cip
itation
(m
m)
RAIN EFFECTBalsa Blanca
0
0.5
1
1.5
2
2.5
3
3.5
SR
Rate
(µm
ol m
-2 s-1
)
Under Plant Biologic Crust Bare Soil
Rainfall Effect
Yan Li. 2008. Have Desert Researchers Discovered A Hidden Loop in the Carbon Cycle?. Science 320: 1409-1410.
Inorganic Carbon
.Understanding of which factors control SR in semiarid ecosystems that have not been considered so far..Quantification of the relative importance of rainfall events on the whole carbon balance..Prediction of SR at ecosystem level by formulating a model that takes into account the temporal, spatial variability. .Impact of land degradation on SR in semiarid regions..Quantification of the dynamics of inorganic C and its contribution to SR.
Expected results