PO3PLAR
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Figure 1. Typical ozone induced injury on Populus maximowiczii Henry x P. x berolinensis Dippel. Foto: M. Schaub, Lattecaldo, WSL.
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The over all objective of PO3PLAR is to complement the Level II ozone
injury assessment program of the ICP-Forests WG on Ambient Air Quality with a well known and already investigated ozone sensitive bio-indicator
species such a Populus spp. A
successful establishment of the indicated bio-indicator on the Light Exposed
Sampling Sites (LESS; see Manual for ‘Assessment of Ozone Injury’)
will allow us to collect additional data on plant responses to ambient ozone
concentrations on the very same species and variety across Europe. Excluding
the disturbing factor of differing species composition of forest ecosystems
and differing species specific responses to ozone (under the given
microclimatic conditions) a harmonized bio-indicator network may allow us to
gain additional valuable information to be implemented in regional as well as
European efforts on ozone risk assessment.
The 2007 season will serve as a test phase providing the participating
countries to gain experience with the optimal planting procedure (soil, water
availability, growth rate, etc.) hopefully leading to first successful
phenological and physiological measurements and observations throughout the
2007 season.
Currently
the following 13 countries are participating in the PO3PLAR
bio-indicator survey: Spain, Italy, France, Lithuania, Hungary,
Germany, Sweden, Czech Republic, Romania, Cyprus, Belgium, USA and Switzerland whereas
Switzerland is serving as the coordinator and data manager.
From an organizational point of view, this project is not an official part
of the ozone injury assessment program of the ICP-Forests WG on Ambient Air
Quality. However, if successful we may be able to attract more interest in
the respective community and hopefully generate some funding in the near
future.
Planting material
We are working with the two following clones, grown at the tree
nursery of the Swiss Federal Institute for Forest, Snow and
Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland:
- Populus
x euramericana (Dode) Guinier cv. Dorskamp)
- Populus maximowiczii Henry x P. x berolinensis Dippel (short name: Oxford clone) >>>
Labeling
For harmonization purposes and easier data management, we suggest the
following labeling code for the cuttings/plants:
Country code (2)_Level II plot (first 3 digits)_poplar clone (5)_plant
number (2)
For example, the code for plant number 2, from the poplar clone x euramericana, grown at the Level II
plot called Bettlachstock in Switzerland (CH) would be: CH_BET_PXEUR_02. Use the code PXMAX, for Populus x maximowiczii.
Suggested time table
October - Preparing and storing
cuttings in cold chambers at WSL
February - Shipping of cuttings to participating countries
March - Growing of cuttings in peat pots under irrigated conditions
June - Invidual planting and
labeling of approx. 1 m tall seedlings in the open field
July - Sept - Maintenance of seedlings; watering and protection against game
Sept - Oct - Observation of onset and development of ozone symptoms
Recommendations for measurements and harvesting
Measurement of tree
heights starting at 10 cm above soil level.
Harvesting and storing above ground biomass. Cutting height = 10 cm above soil level. It is suggested to keep records on fresh biomass (without leaves) as well as on dry weight. You may cut the stem(s) into smaller pieces for easier handling.
For labeling of the plant material, please use the above outlined coding system.
Methods of coordinated
measurement campaigns
(to be completed ...)
Cultivation Greenhouse
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Figure 2. Buried poplar cuttings in peat pots before transplanting into the field
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Before planting the cuttings into the field, we recommend to cultivate seedlings in the green house. In oder to reduce the planting shock, we recommend using peat pots which can be transplanted into the field (Figure 2).
Planting distance
It is recommended to plant the cuttings, seedlings respectively with a
distance of approximately 1 m between each plant to allow sufficient wind
flow to dry the leaves (prevention against pathogens). Consider the plants
may grow over 2 m within one year.
Soil
When planting the cuttings in the field, i.e. at LESS or close to
Level II meteorological measurement station which we strongly recommend (see
objectives) we recommend to loosening the soil down to a depth of
approximately 30 – 50 cm. This will help the roots to grow faster and deeper
to access ground water as soon as possible.
When growing the cuttings in the green house we
recommend to using 10 l pots (diameter 20 cm; height 20 cm). The soil may be
common tree nursery soil with common fertilizer added. Due to the expected
height of the seedlings (over 2 m within one year) we recommend structure
stable soil. The pot should be standing on a plate where overflowing water is
collected and made available to the plant. Note, due to the controlled
conditions within a green house including the application of fertilizer,
artificial light etc., you may conduct experimental studies for your own
purposes but we will not be able to make use of the collected data for any
European wide ozone risk assessment as it is planned for the Level II sites.
Planting depth and
orientation
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Figure 3. Planting
depth and orientation of poplar cutting.
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The cuttings should be planted in the soil with i) the buds looking
upward (check for upper and lower end based on the orientation of the buds)
and with ii) only the top bud sticking out of the soil. This means that most part
of the cutting will be in the soil and only the last top bud will be above
ground, looking upward (Figure 3).
Watering
In the open field, i.e. LESS or vicinity of Level II measurement
station, no fertilizer should be added. Participants from Mediterranean
(dry!) regions may check for sufficient soil moisture and provide the cutting
with sufficient water during the first couple of months, until the plant
roots have accessed ground water.
Protection
According to our experiences, poplar is not a favorite meal of deer.
However, according to the region’s game population you may protect the
seedling against deer damage (fencing). In any case, we recommend to tie the
growing stem to a wooden pole, providing support for the 2 m high and slim
stem to prevent wind damage.
Selected references
Bussotti, F., Strasser, R.J., Schaub, M.,
2007. Photosynthetic behavior of woody species under high ozone exposure probed with the JIP-test: A review. Environmental Pollution 174:430-437. doi:10.1016/j.envpol.2006.08.036
Novak, K., Cherubini, P., Saurer, M., Fuhrer, J., Skelly, J.M.,
Kräuchi, N., Schaub, M., 2007. The effect of
ozone air pollution on tree-ring growth, delta13C, visible foliar injury, and
leaf gas exchange in three ozone-sensitive woody plant species. Tree Physiology 27:941-949.
Novak, K., Schaub, M., Fuhrer, J., Skelly, J.M., Hug, C., Landolt, W., Bleuler,
P., Kräuchi, N., 2005. Seasonal trends in reduced leaf gas exchange and
ozone-induced foliar injury in three ozone sensitive woody plant species.
Environmental Pollution 136:33-45. doi:10.1016/j.envpol.2004.12.018
Günthardt-Goerg M.S., McQuattie C.J., Scheidegger C., Matyssek R.,
Rhiner C., 1997: Ozone-induced cytochemical and ultrastructural changes in
the leaf mesophyll cell wall. Can. J. For. Res.
27: 453-463.
Günthardt-Goerg M.S., 1996: Different responses to ozone of tobacco,
poplar, birch, and alder. J. Plant Physiol. 148: 207-214.
Landolt W., Günthardt-Goerg M.S., Pfenninger I., Scheidegger
C., 1994: Ozone induced microscopical changes and quantitative carbohydrate
contents of hybrid poplar (Populus x euramericana). Trees 8: 183-190.
Links
Contact
Marcus Schaub
Swiss Federal Research Institute WSL
Zuercherstrasse 111
CH-8903 Birmensdorf
Switzerland
| Keywords: |
PO3PLAR, Populus, ozone, risk assessment, bio-indicator, UN/ECE, ICP-Forests, Level II, LWF, Europe |
