harmondepo con eco for harmonization of procedures of ... · fri1 val1 ven1 mar1 umb1 laz2 sar1...
TRANSCRIPT
HARMONDEPOharmonization of procedures of atmospheric deposition samplingTornimbeni O., A. Marchetto, G. A. Tartari, A. Pranzo, P. Giacomotti, A. Orrù, R. Mosello
C.N.R. Institute of Ecosystem Study, Verbania Pallanza, Italy.
VASTA AREA OMOGENEA
50 m
Parcella dianalisi
Parcella dicontrollo
2500 m2
Analysis plot Control plot
Large homogeneous area
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
Analysis plot (50x50) Protection
Stemflowcollectors
Throughfallcollectors
Snowcollectors
9 samplers
0
20
40
60
80
mm H+
NH4+
Ca2+
Mg2+
Na+
K+ Alk Cl
-
SO42-
NO3-
NT DOC
% standard deviation of annual deposition
0
20
40
60
80
mm H+
NH4+
Ca2+
Mg2+
Na+
K+ Alk Cl
-
SO42-
NO3-
NT DOC
Located on a grid
Randomly selected
AIMSThe Harmondepo project aims to evaluate the adequacy of sampling methods adopted by the Italian network CONECOFOR for level II permanent plots, in terms of sample collection and preservation. All analyses were performed on throughfall samples, taken in the permanent plots under the tree canopy.
To evaluate sample stability, all throughfall samples were analysed immediately after their arrival in the laboratory, and then weekly for a month.
To evaluate sampling strategies, different possible combinations and locations of the samplers in the permanent plot were simulated on the basis of individual analyses of 10 weekly samples for each of the 16 throughfall samplers.
To evaluate sampling strategies, field work was performed in the EMI-1 plot (Parco Regionale Boschi di Carrega, Sala Baganza).
In the above sky visions from the different throughfall sampler, it is evident that duringsummer the foliar canopy leads to greater differences in coverage than in winter.
Three plots were sampled in the evaluation of sample stability:PIE-2 Parco Naturale Valle del Ticino,
Bosco VedroPIE-3 Parco Naturale del DeveroEMI-1 Boschi Carrega
SAMPLING STRATEGIES
CHEMICAL STABILITY OF THE SAMPLES
Winter Summer
Simulating the use of 4 samplers, the relative standard deviation is greater for samples located on a grid than for random sample selection. In the case of the 9 samplers differences become very small.
We conclude that 4 samplers are not enough to have a representative sampling of the area. However, 9 samplers are enough to assure that grid sampling presently used does not bias the estimated annual deposition.
Throughfall samplersin a analysis plot .
The use of 4 samplers introduces a relevant increase in % variance for all ionic depositions. Using 9 samplers, the increase in variance is generally markedly lower than random error. For most variables, the increase in variance due to the use of 9 samplers instead of 16 is smaller in winter than in summer, because of the greater homogeneity of the coverage.
We conclude that in summer the present of 16 samplers are necessary for a correct sampling of throughfall deposition. A lower number of snow samples in winter does not imply a substantial increase in the sampling error, because of the greater homogeneity of the area.
% v
aria
nce
% V
aria
nce
CONECOFOR
Rete Nazionale Integrata
Controllo Ecosistemi Forestali
Poster prepared within the CONECOFOR programme, by contract with the Ministry for Agriculture and Forestry Policy – National Forest Service (Italy) in the framework of the EU Regulation (EC) No 2152/2003 (“Forest Focus”) and of the UN/ECE Program “ICP Forests”.
CONECOFOR
Rete Nazionale Integrata
Controllo Ecosistemi Forestali
% V
aria
nce
% V
aria
nce
Four samples were analysed immediately after arrival in the laboratory, then stored in a dark room at 4° C for a month. All the analyses were repeated weekly.
Ionic concentration randomly varied from analysis to analysis generally within a +/- 5% range around the initial values, which is comparable with the analytical error of the method used.
In conclusion, throughfall samples can be stored up to one month without introducing further analytical errors, butprecautions should be taken in their preservation, such asstoring them in a dark cold room.
VARIANCE PARTIONING FOR ANNUAL DEPOSITION
was estimated by repeated random or regular selection of 4, 9 and 16 samplers from the set of 16 samplers actually analysed
Winter Simulation of 9 sampler Summer
Simulation of 4 samplers Simulation of 9 samplers
Random error using 16 samplers Analytical errorIncreased variance using 9 samplers instead of the whole set of 16Increased variance using 4 samplers instead of 9
GRID VS. RANDOM LOCATION
4 samplers
LOM1TRE1
FRI2
EMI2
TOS1
LAZ1 ABR1
CAM1
SIC1
CAL1
TOS3
TOS2
BOL1
LOM 3LOM2
FRI1VAL1VEN1
MAR1UMB1
LAZ2
SAR1
PUG1
ABR2
BAS1
LIG1
FRI2
PIE1
PIE2
PIE3
EMI1
LOM1
THF 1 THF 2 THF 3 THF 4
THF 5 THF 6 THF 7 THF 8
THF 9 THF 10 THF 11 THF 12
THF 13 THF 14 THF 15 THF 16
THF 1 THF 2 THF 3 THF 4
THF 5 THF 6 THF 7 THF 8
THF 9 THF 10 THF 11 THF 12
THF 13 THF 14 THF 15 THF 16
0%
20%
40%
60%
80%
100%
mm H+
NH4+
Ca2+
Mg2+
Na+
K+ Alk Cl
-
SO42-
NO3+
NT DOC
100%
-30%
-20%
-10%
0%
10%
20%
30%
21/12/06
03/01/07
09/01/07
17/01/07
31/01/07
pH Cond
Cl SO
NO Ca
Mg Na
RP NT
DOC Alk
NH K
4
3
4
- 2-
-
+2+
+
2+
+-30%
-20%
-10%
0%
10%
20%
30%
23/02/06
27/02/06
07/03/06
16/03/06
21/03/06
pH Cond
Cl SO
NO Ca
Mg Na
NH RP
NT DOC
Alk K
4
3
4
- 2-
-
+2+
+
2+
+
Author for correspondence: [email protected]
0%
20%
40%
60%
80%
100%
mm H+
NH4+
Ca2+
Mg2+
Na+
K+ Alk Cl
-
SO42-
NO3-
NT DOC
0%
20%
40%
60%
80%
mm H+
NH4+
Ca2+
Mg2+
Na+
K+ Alk Cl
-
SO42-
NO3-
NT DOC
0%
20%
40%
60%
80%
100%
mm H+
NH4+
Ca2+
Mg2+
Na+
K+ Alk Cl
-
SO42-
NO3-
NT DOC