GLI IMPATTI DELL’INQUINAMENTO ATMOSFERICO SUGLI ECOSISTEMI NATURALI E ANTROPICI
23 - 24 Gennaio 2014 ENEA, Via Giulio Romano, 41 – Roma
Marcello Vitale, Fabio Attorre, Michele De Sanctis Dipartimento di Biologia Ambientale Sapienza Università di Roma
Con i contributi di:
Maria Francesca Fornasier - ISPRA, Roma
Alessandra De Marco - ENEA, CR Casaccia, Santa Maria di Galeria - Roma)
Topic: I carichi critici per la valutazione degli impatti sulla Biodiversità
Carichi critici, eccedenze e biodiversità: sviluppo di nuovi
approcci e metodologie
Nitrogen emissions and deposition of nitrogen compounds have decreased since 1990 but relatively little compared to sulphur emissions. Agriculture and transport are the main sources of nitrogen pollution (EEA, 2007). In addition, nitrogen components can lead to eutrophication of ecosystems. When this pollution exceeds certain levels ('critical load'), it is damaging to biodiversity. Critical load exceedance is still significant(1).
(1) The critical load of nutrient nitrogen is defined as 'the highest deposition of nitrogen as NOX and/or NHY
below which harmful effects in ecosystem structure and function do not occur according to present
knowledge' (ICP, M&M, 2004).
Rationale
Available at: www.eea.europa.eu/publications/eea_report_2007_2.
A critical load is defined as “a quantitative estimate of an exposure to one or more pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur according to present knowledge” (Nilsson and Grennfelt, 1988). Exceedances of critical loads by current or future nitrogen loads indicate risks for adverse effects on biodiversity.
Rationale
Excess nitrogen is one of the major threats to biodiversity. Excessive levels of reactive forms of nitrogen in the biosphere and atmosphere constitute a major threat to biodiversity in terrestrial, aquatic and coastal ecosystems.
On land it causes loss of sensitive species and hence biodiversity by favouring a few nitrogen tolerant species over less tolerant ones.
In coastal waters it leads to algal blooms and deoxygenated dead zones in which only a few bacteria may survive. Questions
Is it possible to evaluate a plant population changes induced by climate and air pollutants into the plant community?
How are actual biodiversity indices useful for this assessment, taking into account limited database either in time or in space?
Rationale
Study areas
Study areas
Kg/ha/y
Test sites location
Nitrogen depositions in Italy
Significant differences among N exceedances (above, BOF N and under BSC N canopy) of the monitored sites have been found by ANOVA test
Categ. Box & Whisker Plot: Exceed BSC N
Mean Mean±SE Mean±SD
LOM1 ABR1 LAZ1
Site
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
Exc
eed
BS
C N
Categ. Box & Whisker Plot: Exceed BOF N
Mean Mean±SE Mean±SD
LOM1 ABR1 LAZ1
Site
-14
-12
-10
-8
-6
-4
-2
0
2
4
6
8
Exc
eed
BO
F N
*
*
*
*
*
*
Study areas
Temporal trends of exceedances above (BOF N) and under canopy (BSC N) calculated for the three test sites
Sites conecofor isprakg/ha/yr kg/ha/yr
LOM 1 16.40 10.19ABR 1 11.48 16.93LAZ 1 13.15 10.42
Critical Loads for the three test sites
Box Plot of Exceed BSC N grouped by Years; categorized by Site
Years
Exc
eed
BS
C N
Mean Mean±SE Mean±2*SD
Site: LOM1
20002001
20022003
20042005
20062007
20082009
-14-12-10
-8-6-4-202468
1012
Site: ABR1
20002001
20022003
20042005
20062007
20082009
Site: LAZ1
20002001
20022003
20042005
20062007
20082009
-14-12-10
-8-6-4-202468
1012
Box Plot of Exceed BOF N grouped by Years; categorized by Site
Years
Exc
eed
BO
F N
Mean Mean±SE Mean±2*SD
Site: LOM1
20002001
20022003
20042005
20062007
20082009
-14-12-10
-8-6-4-202468
1012
Site: ABR1
20002001
20022003
20042005
20062007
20082009
Site: LAZ1
20002001
20022003
20042005
20062007
20082009
-14-12-10
-8-6-4-202468
1012
Study areas
LOM1
Study areas
The values of the diversity indices are not always comparable between them and depend on the extent to which they can actually vary.The evenness is a measure of diversity normalized on a fixed scale (e.g. from 0 to 1) and allows to carry out these comparisons.
From the Shannon-Wiener index, the Pielou’s evenness can be defined as:
Ellenberg, in a series of publications (Ellenberg 1979, 1988; Ellenberg et al. 1991), defined a set of indicator values for the vascular plants of central Europe. These have been widely used, both in central Europe and in adjacent parts of western Europe. The basis of indicator values is the realised ecological niche. Plants have a certain range of tolerance of temperature, light, soil pH, and so on. If we wish to make inferences about the ecological conditions pertaining at a site, much useful information can be obtained from the flora. These values are not i.e. mean pH values, but are on an arbitrary scale reflecting soil pH though not directly based on measurements. However, an advantage of indicator values is that they may be more sensitive to the requirements of plants than is a selected physical variable.
Categ. Box & Whisker Plot: Ellen. Soil N
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
6.0
Elle
n. S
oil N
Categ. Box & Whisker Plot: Ellen. Soil pH
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
4.2
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
6.0
6.2
6.4
6.6
Elle
n. S
oil p
H
Categ. Box & Whisker Plot: Ellen. Cont
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
2.6
2.8
3.0
3.2
3.4
3.6
3.8
Elle
n. C
ont
Categ. Box & Whisker Plot: Ellen. Temp
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
4.0
4.2
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
6.0
6.2
Elle
n. T
emp
*
**
*
*
*
*
*
*
*
*
*
Categ. Box & Whisker Plot: J=H'/Hmax
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
0.7
0.8
0.9
1.0
J=H
'/Hm
ax
Categ. Box & Whisker Plot: H'dunestd
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
H'd
unes
td
Categ. Box & Whisker Plot: BSC N
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
6
8
10
12
14
16
18
BS
C N
Categ. Box & Whisker Plot: BOF N
Mean Mean±SE Mean±1.96*SE
LOM1 ABR1 LAZ1
Site
6
7
8
9
10
11
12
13
14
15
16
BO
F N
**
*
*
* *
Variability Plot of J=H'/Hmax
Raw Data Connect MeansLOM1 ABR1 LAZ1
1999
2000
2001
2002
2003
2004
2005
2006
2008
2009
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Site
Years0.70
0.72
0.74
0.76
0.78
0.80
0.82
0.84
0.86
0.88
0.90
0.92
0.94
J=H
'/Hm
ax
Variability Plot of H'dunestd
Raw Data Connect MeansLOM1 ABR1 LAZ1
1999
2000
2001
2002
2003
2004
2005
2006
2008
2009
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Site
Years0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
H'd
unes
td
Variability Plot of BSC N
Raw Data Connect MeansLOM1 ABR1 LAZ1
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Site
Years2
4
6
8
10
12
14
16
18
20
22
BS
C N
Variability Plot of BOF N
Raw Data Connect MeansLOM1 ABR1 LAZ1
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Site
Years4
6
8
10
12
14
16
18
20
22
BO
F N
Site=LOM1 Correlations Marked correlations are significant at p < .05000 N=9
H' J H'duneH'dune
std
Exceed BSC N
0.27 0.26 0.26 0.27
Exceed BOF N
0.33 0.49 0.59 0.70
Ellen. Light
0.10 0.06 -0.39 -0.41
Ellen. Temp
-0.03 -0.15 0.09 -0.02
Ellen. Cont
0.17 0.29 -0.27 -0.15
Ellen. Soil Moist
0.07 0.10 0.07 0.12
Ellen. Soil pH
-0.16 -0.32 0.07 -0.07
Ellen. Soil N
0.01 -0.06 0.26 0.20
Site=ABR1 Marked correlations are significant at p < .05000 N=10
H' J H'duneH'dune
std
Exceed BSC N
-0.05 0.30 0.40 0.36
Exceed BOF N
-0.39 -0.40 0.01 0.06
Ellen. Light
0.12 0.41 0.25 0.21
Ellen. Temp
-0.00 0.16 -0.15 -0.14
Ellen. Cont
-0.22 -0.05 -0.05 -0.04
Ellen. Soil Moist
-0.13 0.19 0.01 -0.02
Ellen. Soil pH
0.00 0.12 -0.13 -0.16
Ellen. Soil N
0.60 0.57 0.25 0.17
Site=LAZ1 Marked correlations are significant at p < .05000 N=10
H' J H'duneH'dune
std
Exceed BSC N
0.51 0.49 -0.08 -0.16
Exceed BOF N
0.51 0.44 0.31 0.21
Ellen. Light
-0.56 -0.47 -0.24 -0.13
Ellen. Temp -0.67 -0.72 0.29 0.39
Ellen. Cont -0.90 -0.88 0.01 0.16
Ellen. Soil Moist
0.78 0.75 0.08 -0.05
Ellen. Soil pH
0.26 0.29 -0.34 -0.37
Ellen. Soil N
0.21 0.16 -0.27 -0.30
Correlation analysis showed that generally diversity indices did not correlate with the Ellenberg’s indicators except H’ in the LAZ1 site, but
H’dunestd correlated with N exceedances above canopy in LOM1.
The application of more advanced statistical analyses (such as the Random Forest in the Data Mining statistical tools) did not result into a clear causal pattern between biodiversity indices and environmental and pollution factors. Likely this was due to a very poor dataset.
Nox Nred
% of the total
It should be taken into consideration that N depositions may have different distributions along the peninsula regard their oxidative state and, as a consequence, different effects on vegetation (De Marco et al., 2013)
De Marco, Screpanti, Attorre, Proietti, Vitale (2013) Assessing ozone and nitrogen impact on net primary productivity with a Generalised non-Linear Model. Environmental Pollution, 172: 250-263.
REMARKS
These simple analyses highlighted that different diversity indices (one based on the species proportion and the other based on proportional coverage area) could suggest different trends, which were not in correlation with climatic data and N depositions for three herbaceous communities growing under different ecological niches;
It seems that one decade of data it is not sufficient for assessing a change in herbaceous community’s composition;
Inferences made on the air pollutant-induced effects in affecting plant community’s composition should be carried out with extreme caution;
Wide database with plant community information, air pollutant and climate should be used for non linear statistical analyses, in order to provide inferring statistical models;
The spatial pattern of plant distribution should be taken in consideration when plant diversity indices are applied for different monitoring plots. Actually, this structural parameter is not considered;
The application of different biodiversity indices and ecological indicators should be applied in extensive way to other European herbaceous plant communities, in order to assess if air pollutants, and/or climate, and or anthropogenic activities are causal effects for a changing plant communities.
REMARKS
Grazie per Grazie per l’attenzione !l’attenzione !
Top Related