Post on 17-Aug-2020
Analysis of adaptive capacity of Croatian Mediterranean forests to
climate change by using various indicators of tree and stand vitality
Ognjenović M. 1, Seletković I. 1, Timmermann V. 2, Potočić N. 1
1 Croatian Forest Research Institute, Cvjetno naselje 41, 10450 Jastrebarsko, Republic of Croatia
2Norwegian Institute of Bioeconomy Research P.O. Box 115, NO-1431 Ĺs, Norway
Project Background
Materials & Methods
Preliminary results
Further steps
• Mediterranean forests in Croatia account for 24% of total forest area.
• Important social and ecological functions (preservation of soil, air, water and
biodiversity; carbon sequestration; impact on microclimate conditions;
aesthetic and touristic function etc.).
• Several factors have been recognized to influence tree vitality, and the
reasons for the deterioration of tree condition can be found in specific
interactions of stress factors. More in-depth knowledge about the level of
stress and adaptive capacity of forests in Croatian Mediterranean is needed to
enable predictions of their future development
Research Aims
• Determine the spatio-temporal variability in condition of forest ecosystems
through the use of various indicators of tree and stand vitality
(increment, tree mineral nutrition, crown defoliation, and taking into account
soil characteristics, elevation, inclination, stand structure and floral composition,
exposition, soil erosion risks and climate influences)
• Explore interactions between indicators of forest ecosystem condition
• Determine the current adaptive capacity of Croatian Mediterranean forests to
climate change
Plots
• UNECE-ICP Forests large-scale
(Level I) plot network, 16x16 km grid
• National forest monitoring plot
network, 4x4 km grid
Defoliation data
• Crown defoliation assessed using the
approach established by ICP Forests
(Eichhorn et al., 2016)
• Time period: 2000 - 2016
• Plots were selected for analysis if
they were assessed at least 90% of the
time period
Sampling and Analysis of Needles
and Leaves
• We sampled 5 trees for each dominant
tree species on a specific ICP Forests
Level I plot, their defoliation
corresponding to the mean plot
defoliation
•Samples were collected by tree climbing
(double rope system), extension shears or
by the use of shotgun
• Samples were analysed following
methods described in ICP Forests Manual
(Rautio et al., 2016)
REFERENCES
Eichhorn, J., Roskams, P., Ferretti, M., Mues, V., Szepesi, A., Durrant, D., 2010 Visual Assessment of Crown Condition and Damaging Agents. Manual Part IV, In: Manual on Methods and Criteria for Harmonized Sampling,
Assessment, Monitoring and Analysis of the Effects of Air Pollution on Forests. UNECE ICP Forests Programme Coordinating Centre, Hamburg. ISBN: 978-3926301-1. <http://www.icp-forests.org/Manual.htm>.
GTOS (Global Terrestrial Observing System), 2008 TCO: Terrestrial Carbon Observations: Protocols for Vegetation Sampling and Data Submission, B.E. Law, T. Arkebauer, J. L. Campbell, J.Chen, O. Sun, M. Schwartz, C. van
Ingen, S. Verma (ed.), Rome
Stefan, K., Furst, A., Hacker, R. and Bartels, U., 1997 Forest Foliar Condition in Europe results of large-scale foliar chemistry surveys. EC-UN/ECE and FBVA.
Rautio P, Fürst A, Stefan K, Raitio H, Bartels U, 2010 Sampling and Analysis of Needles and Leaves.19 pp. Manual Part XII. In: Manual on methods and criteria for harmonized sampling, assessment, monitoring and
analysis of the effects of air pollution on forests, UNECE, ICP Forests Programme Co-ordinating Centre, Hamburg. ISBN: 978-3-926301-03-1. [http://www.icpforests.org/Manual.htm]
Rautio, P. and Fürst, A. 2013 Tree Foliage. Developments in Environmental Science, 12, 223-236.
ACKNOWLEDGMENTS
This publication was financed by the Ministry of Agriculture (Republic of Croatia), from the funds of the Beneficial Forest Functions Fee. The opinions expressed here do not necessarily reflect the views of the Ministry of Agriculture.
Overall defoliation trend of most frequent tree species (red line):
• Quercus cerris (Theil/Sen slope: 0.309, p= 0.08),
• Quercus pubescens (Theil/Sen slope = 0.391, p= 0.017)
• Pinus halepensis (Theil/Sen slope = 0.523, p = 0.016)
(Annual overall mean defoliation is represented by black lines. Points represent
annual plot defoliation means.)
High Ca in all species is expected due to predominantly Ca-rich soils. Mean foliar nutrient concentrations observed across all plots (black line)
compared to element concentration classes reported by Rautio and Fürst (2013).
Results of Kruskal-Wallis rank sum tests confirm
that overall mean defoliation varies by orientation.
(Size of the wedge indicates the proportion of plots in
our database according to orientation while the color
scale shows mean plot defoliation of the entire time
period for a certain orientation.)
• Continue assessment of crown condition on both monitoring networks
• Continue foliar sampling on ICP Forests Level I plots
• Soil, litter and woody debris sampling and measurement on ICP Forests Level I
plots
• Time series analysis on climate data (E-OBS gridded dataset)
• Stand structure measurements by adapting TCO protocol (GTSO, 2008) and
Croatian National Forest Inventory
• Tree Increment Coring of all trees on ICP Forests Level I plots