Download Presentation - Copernicus.org

European Geoscience Union General Assembly, 17-22 April, Vienna Austria
SOIL SUSTAINABILITY RESEARCHES IN LITHUANIAN ALIEN FOREST STANDS
Introduction
Global warming could enlarge the expansion of Northern
red oak and European larch into Lithuanian forests. At present,
Northern red oak is considered as invasive species in Poland
and at invasive stage in the Lithuanian forests (Riepšas and
Straigytė, 2008). Meanwhile, European larch grew naturally in
Lithuania in the sixteenth century and was reintroduced 200
years ago.
It is well documented that mineral weathering is one of
the major factors which influences the soil nutrient stocks and
soil sustainability. But how these non-native tree species
contribute to he mineral weathering process is still not
understood.
Aim of the study
The main goal of this study was to determine the mineral
weathering rates in alien forest stands using a PROFILE soil
chemistry model.
Dovilė Čiuldienė1, Gražina Skridlaitė2, Gailė Žalūdienė2, Cecilia Askelsson3, Kęstutis Armolaitis1
1Institute of Forestry of Lithuanian Research Centre for Agriculture and Forestry
2Laboratory of Bedrock Geology, Nature Research Centre
3 Department of Physical Geography and Ecosystem Sciences, Lund University
Mineralogical
Results
Table 1. Mean dendrometric characteristics of the European larch and Northern red oak forest
stands
Tree species
Age
Tree density
DBH
Height
Basal area
Stem wood production
(years)
(ha-1)
(cm)
(m)
(m2 ha-1)
(m3 ha-1)
European larch
157
230
60.0
41.0
68.6
1244.6
European larch
47
510
30.8
32.3
40.7
600.0
European larch
47
880
28.6
31.2
59.6
850.6
Northern red oak
55
720
24.6
25.6
35.4
426.7
Northern red oak
45
1040
20.7
24.8
36.7
433.8
Northern red oak
45
1080
20.4
24.5
36.5
422.5
Mineral composition (%)
Horizon
Epidote
Quartz
Chlorite
Hornblende
Feldspar
Illite
Muscovite
Albite
B
n. d.
50.0±5.7
n. d.
5.0±1.6
8.3±1.6
n. d.
30.0±12.5
n. d.
Loamy sand
C
n. d.
20.0±5.6
1.3±1.3
16.3±3.7
13.3±6.7
13.3±8.8
21.7±10.9
n. d.
Sandy loam
Grassland
B
0.5±0.5
45.0±5.0
n. d.
1.5±0.5
7.5±0.5
25.0±5.0
17.5±2.5
n. d.
Sandy loam
C
0.5±0.5
25.0±10.0
n. d.
1.0±0.0
9.5±0.0
32.5±7.5
27.5±7.5
n. d.
clay loam
B
n. d.
25.5±5.0
n. d.
7.5±2.5
n. d.
35.0±5.0
20.0±10
n. d.
Silt and
Sandy loam
Clay
PROFILE model is a steady state soil chemistry model which
is used to calculate a soil weathering rate (Warfvinge and
Sverdrup, 1992). This model requires: data of climate (mean
annual temperature & precipitation), chemical parameters of wet
& dry atmospheric depositions, forest plantation dendrometric &
chemical (wood, foliage litterfall) characteristics, soil physical
parameters (density, textural classes) and
soil mineral
composition. The model estimates a weathering rate of Ca2+, Mg2+
and K+ through the soil profile (0-80 cm) in mmolc m-3 per year.
The PROFILE model was adopted in cooperation with dr. Cecilia
Akselsson (Dept. of Physical Geography & Ecosystems Science,
Lund university).
Larch 157year-old
Weathering rates, mmolc m-3 per
year
Model description
C
n. d.
15.5±0.5
n. d.
8.0±3.0
n. d.
45.0±1.5
15.5±5.0
n. d.
B
n. d.
20.5±5.5
0.5±0.5
3.5±1.5
n. d.
15.0±2.0
40.0±10.0
7.5±7.5
C
n. d.
15.5±0.5
n. d.
7.5±2.5
4.0±1.0
35.0±5.0
25.0±5.0
n. d.
Silt and
Sandy loam
Clay
20
Northern red oak
15
A
Perennial grassland
10
5
0
Ca+Mg+K
80
70
60
50
40
30
20
10
0
Fig. 1. Determination of K-feldspar using
Scanning Electron Microscopy
Textural
classes
Type of
vegetation
Northern
red oak
Weathering rates, mmolc m-3 per
year
This study was carried out in the 47 and 157-year-old
European larch (Larix decidua Mill.), 45-55-year-old Northern
red oak (Quercus rubra L.) plantations and in adjacent
perennial grassland. The soils were Luvisols with clayey loam
at different depths. The soils were developed from
glaciofluvial deposits in both the studied plantations (Table 1).
Mineral chemical compositions were determined in the
Laboratory of Bedrock Geology of Nature Research Centre. They
were analyzed in cooperation with dr. Gražina Skridlaitė. Soil
samples were taken from B and C horizons in three replicates per
forest stand. Mineral composition was analyzed by a Scanning
Electron Microscopy (SEM) (Fig.1) (Table 2).
Table 2. Mineral composition in the Northern red oak forest stands with adjacent perennial
grassland and in the differently aged European larch plantations.
Larch 47year-old
Study sites
composition studies
Ca2+
Mg2+
K+
B
European larch age
47
157
Ca+Mg+K
Ca2+
Mg2+
K+
Fig. 2. The weathering rates of base cations in the Northern red oak (A) and European larch (B)
plantations. The depth of clayey loam was 60-70 in the Northern red oak and 40-60 in European larch
plantations.
However, the finest clay fraction mainly consisted of small
secondary clay minerals and few primary minerals, therefore
minerals were identified by the percentage of oxides (%) and
mineral formula was adjusted using a mineral recalculation
program “Mineral Recalculation Software”(http://www.open.ac. uk
/ earth-research / Tindle / AGTWebPages / AGTSoft.html).
What did we find?
•
B horizons of the studied glaciofluvial deposits contained in
average 35% of quartz, 20% of both illite and muscovite; ~10%
of feldspar and hornblende. C horizons consisted of 30% illite,
20% quartz and muscovite, and 10% hornblende and feldspar in
average.
• Depth of the clayey loam is one of the main factors influencing
weathering rates.
• However, a 30% higher sum of cations (Ca + Mg+ K) weathering
rate in the soil under the Northern red oak than in adjacent
perennial grassland was estimated. Meanwhile, the
aforementioned parameter in the differently-aged European larch
plantations does not differ much.
Conclusions
The obtained results showed that over the 100 year the mineral
weathering process was in equilibrium in the European larch
plantations. However, the Northern red oak has accelerated
mineral weathering rates in comparison with the adjacent
perennial grassland.
Acknowledgement This research was funded by a grant (no. LEK-19/2010) from
the Research Council of Lithuania and also was supplemented by the long-term
research programme “Sustainable forestry and global changes”, implemented by
the Lithuanian Research Centre for Agriculture and Forestry.