Alpine Forest Drought Monitoring in South Tyrol: PCA Based Synergy between scPDSI Data and MODIS Derived NDVI and NDII7 Time Series

Observed alternation of global and local meteorological patterns governs increasing drought impact, which puts at risk ecological balance and biodiversity of the alpine forest. Despite considerable attention, drought impact on forest ecosystems is still not entirely understood, and comprehensive forest drought monitoring has not been implemented. In this study, we proposed to bridge this gap exploiting a time-domain synergetic use of medium resolution MODSI NDVI (Normalized Difference Vegetation Index) and NDII7 (Normalized Difference Infrared Index band 7) time series as well as on-station temperature and precipitation measures combined in the scPDSI (self-calibrated Palmer Drought Severity Index) datasets. Analysis employed the S-mode Principal Component Analysis (PCA) examined under multiple method settings and data setups. The investigation performed for South Tyrol (2001–2012) indicated prolonged meteorological drought condition between 2003 and 2007, as well as general drying tendencies. Corresponding temporal variability was identified for local mountain forest. The former response was fostered more often by NDII7, which is related to foliage water content, whereas NDVI was more prone to report on an overall downturn and implied drop in forest photosynthetic activity. Among tested approaches, the covariance-matrix based S-mode PCA of z-score normalized vegetation season NDVI and NDII7 time series ensured the most prominent identification of drought impact. Consistency in recognized temporal patterns confirms integrity of the approach and aptness of used remote-sensed datasets, suggesting great potential for drought oriented environmental analyses.

[1]  H. Kaiser.  The varimax criterion for analytic rotation in factor analysis , 1958 .

[2]  Bernard Tychon,et al.  Studying interactions between climate variability and vegetation dynamic using a phenology based approach , 2013, Int. J. Appl. Earth Obs. Geoinformation.

[3]  M. Dobbertin,et al.  Tree growth in Swiss forests between 1995 and 2010 in relation to climate and stand conditions: Recent disturbances matter , 2014 .

[4]  D. Morton,et al.  Impact of sensor degradation on the MODIS NDVI time series , 2012 .

[5]  R. Cattell.  The Scree Test For The Number Of Factors. , 1966, Multivariate behavioral research.

[6]  Benoît Courbaud,et al.  What is the future of the ecosystem services of the Alpine forest against a backdrop of climate change , 2011 .

[7]  Niklaus E. Zimmermann,et al.  Potential Future Ranges of Tree Species in the Alps , 2013 .

[8]  Keith R. Briffa,et al.  European Alpine moisture variability for 1800–2003 , 2007 .

[9]  Niklaus E. Zimmermann,et al.  Divergent vegetation growth responses to the 2003 heat wave in the Swiss Alps , 2005 .

[10]  A. Dai.  Characteristics and trends in various forms of the Palmer Drought Severity Index during 1900–2008 , 2011 .

[11]  Christof Bigler,et al.  Drought as an Inciting Mortality Factor in Scots Pine Stands of the Valais, Switzerland , 2006, Ecosystems.

[12]  Keith R. Briffa,et al.  A scPDSI‐based global data set of dry and wet spells for 1901–2009 , 2013 .

[13]  V. Singh,et al.  A review of drought concepts , 2010 .

[14]  O. Dupont,et al.  An analysis of the July 2006 heatwave extent in Europe compared to the record year of 2003 , 2009 .

[15]  K. Price,et al.  Regional vegetation die-off in response to global-change-type drought. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[16]  L. Ji,et al.  Assessing vegetation response to drought in the northern Great Plains using vegetation and drought indices , 2003 .

[17]  Antoine Guisan,et al.  Tree line shifts in the Swiss Alps: Climate change or land abandonment? , 2007 .

[18]  Hao Chen,et al.  Implications of space-time orientation for Principal Components Analysis of Earth observation image time series , 2011, Earth Sci. Informatics.

[19]  H. Kaiser.  The Application of Electronic Computers to Factor Analysis , 1960 .

[20]  A. Viña,et al.  Drought Monitoring with NDVI-Based Standardized Vegetation Index , 2002 .

[21]  G. Burroughs,et al.  THE ROTATION OF PRINCIPAL COMPONENTS , 1961 .

[22]  Pascale Weber,et al.  Growth response of five co-occurring conifers to drought across a wide climatic gradient in Central Europe , 2014 .

[23]  Rolf Philipona,et al.  How declining aerosols and rising greenhouse gases forced rapid warming in Europe since the 1980s , 2009 .

[24]  J. Eastman,et al.  Long sequence time series evaluation using standardized principal components , 1993 .

[25]  M. Carrer,et al.  Summer climate variability over the last 250years differently affected tree species radial growth in a mesic Fagus–Abies–Picea old-growth forest , 2014 .

[26]  M. Manthey,et al.  Drought matters – Declining precipitation influences growth of Fagus sylvatica L. and Quercus robur L. in north-eastern Germany , 2011 .

[27]  A. Dai.  Drought under global warming: a review , 2011 .

[28]  P. O. White,et al.  PROMAX: A QUICK METHOD FOR ROTATION TO OBLIQUE SIMPLE STRUCTURE , 1964 .

[29]  Filippo Bussotti,et al.  Functional traits and adaptive capacity of European forests to climate change , 2015 .

[30]  C. Appenzeller,et al.  A comparative study of satellite and ground-based phenology , 2007, International journal of biometeorology.

[31]  B. Gao.  NDWI—A normalized difference water index for remote sensing of vegetation liquid water from space , 1996 .

[32]  P. Ciais,et al.  Europe-wide reduction in primary productivity caused by the heat and drought in 2003 , 2005, Nature.

[33]  Keith R. Briffa,et al.  Summer Moisture Variability across Europe , 2006 .

[34]  Michele Brunetti,et al.  A new instrumental precipitation dataset for the greater alpine region for the period 1800–2002 , 2005 .

[35]  David Frank,et al.  Tree-ring indicators of German summer drought over the last millennium , 2010 .

[36]  Christopher Conrad,et al.  TiSeG: A Flexible Software Tool for Time-Series Generation of MODIS Data Utilizing the Quality Assessment Science Data Set , 2008, IEEE Transactions on Geoscience and Remote Sensing.

[37]  Niklaus E. Zimmermann,et al.  Climate change may cause severe loss in the economic value of European forest land , 2013 .

[38]  Giorgio Vacchiano,et al.  Evidences of drought stress as a predisposing factor to Scots pine decline in Valle d’Aosta (Italy) , 2011, European Journal of Forest Research.

[39]  R. Lasaponara.  On the use of principal component analysis (PCA) for evaluating interannual vegetation anomalies from SPOT/VEGETATION NDVI temporal series , 2006 .

[40]  Chi Hau Chen,et al.  Statistical pattern recognition in remote sensing , 2008, Pattern Recognit..

[41]  Olivier Dupont,et al.  Heat and drought 2003 in Europe: a climate synthesis , 2006 .

[42]  Carlos C. DaCamara,et al.  Drought and vegetation stress monitoring in Portugal using satellite data , 2009 .

[43]  Isabel F. Trigo,et al.  The Outstanding 2004/05 Drought in the Iberian Peninsula: Associated Atmospheric Circulation , 2007 .

[44]  Christian Ginzler,et al.  Driving factors of a vegetation shift from Scots pine to pubescent oak in dry Alpine forests , 2013, Global change biology.

[45]  Pascale Weber,et al.  Growth reactions of Pinus sylvestris L. and Quercus pubescens Willd. to drought years at a xeric site in Valais, Switzerland , 2006 .

[46]  Gerard Hazeu,et al.  Europe's ecological backbone: recognising the true value of our mountains , 2010 .

[47]  J. Ronald Eastman,et al.  Novel approaches in Extended Principal Component Analysis to compare spatio-temporal patterns among multiple image time series , 2014 .

[48]  Niklaus E. Zimmermann,et al.  Future Climate of the European Alps , 2013 .

[49]  Christopher Small,et al.  Spatiotemporal dimensionality and Time-Space characterization of multitemporal imagery , 2012 .

[50]  D. Lüthi,et al.  The role of increasing temperature variability in European summer heatwaves , 2004, Nature.

[51]  C. Tucker.  Red and photographic infrared linear combinations for monitoring vegetation , 1979 .

[52]  A. Guisan,et al.  Potential Impact of Climate Change on Vegetation in the European Alps: A Review , 2001 .

[53]  P. Bernier,et al.  Adapting forestry and forests to climate change: a challenge to change the paradigm. , 2012 .

[54]  Walter Oberhuber,et al.  Radial growth response of coniferous forest trees in an inner Alpine environment to heat-wave in 2003 , 2007 .

[55]  Stefan Sommer,et al.  Ecosystem functional units characterized by satellite observed phenology and productivity gradients: A case study for Europe , 2013 .

[56]  Michele Brunetti,et al.  HISTALP—historical instrumental climatological surface time series of the Greater Alpine Region , 2007 .

[57]  A. Huete,et al.  Overview of the radiometric and biophysical performance of the MODIS vegetation indices , 2002 .

[58]  C. Appenzeller,et al.  Inter-Annual Variability and Decadal Trends in Alpine Spring Phenology: A Multivariate Analysis Approach , 2005 .

[59]  K. Price,et al.  Temporal responses of NDVI to precipitation and temperature in the central Great Plains, USA , 2003 .

[60]  Euskadi. Servicio de Cartografía.  Corine Land Cover , 2012 .

[61]  P. Barbosa,et al.  The biggest drought events in Europe from 1950 to 2012 , 2015 .

[62]  Joel Parshall,et al.  Building for a Strong Future , 2011 .

[63]  Marc Hanewinkel,et al.  Management Strategies to Adapt Alpine Space Forests to Climate Change Risks , 2013 .

[64]  Rasmus Fensholt,et al.  Drought footprint on European ecosystems between 1999 and 2010 assessed by remotely sensed vegetation phenology and productivity , 2014, Global change biology.

[65]  James Dean Brown,et al.  Choosing the Right Type of Rotation in PCA and EFA , 2009 .

[66]  R Colombo,et al.  European larch phenology in the Alps: can we grasp the role of ecological factors by combining field observations and inverse modelling? , 2008, International journal of biometeorology.

[67]  John L. Dwyer,et al.  Landsat: building a strong future , 2012 .

[68]  B. Lloyd‐Hughes,et al.  A drought climatology for Europe , 2002 .

[69]  P. D. Körner.  Alpine Plant Life , 1999, Springer Berlin Heidelberg.

[70]  J. W. Wagtendonk,et al.  Comparison of AVIRIS and Landsat ETM+ detection capabilities for burn severity , 2004 .

[71]  Jason W. Osborne,et al.  Best practices in exploratory factor analysis: four recommendations for getting the most from your analysis. , 2005 .

[72]  Guirui Yu,et al.  Regional drought-induced reduction in the biomass carbon sink of Canada's boreal forests , 2012, Proceedings of the National Academy of Sciences.

[73]  Harald Bugmann,et al.  Reduction of stand density increases drought resistance in xeric Scots pine forests , 2013 .

[74]  Andreas Rigling,et al.  Ecological interpretation of tree-ring width and intraannual density fluctuations in Pinus sylvestris on dry sites in the central Alps and Siberia , 2001 .

[75]  S. Larsson,et al.  A rapid altitudinal range expansion in the pine processionary moth produced by the 2003 climatic anomaly , 2006 .

[76]  Pascal Vittoz,et al.  Effects of Climate and Land-Use Change on the Establishment and Growth of Cembran Pine (Pinus cembra L.) over the Altitudinal Treeline Ecotone in the Central Swiss Alps , 2008 .

[77]  D. Wilhite,et al.  CHAPfER2UNDERSTANDING THE DROUGHT PHENOMENON:THE ROLE OF DEFINITIONS , 1985 .

[78]  J. Vogt,et al.  Climatic response and impacts of drought on oaks at urban and forest sites , 2013 .

[79]  Stefan Strobl,et al.  Impact of drought on the temporal dynamics of wood formation in Pinus sylvestris. , 2010, Tree physiology.

[80]  Thomas Udelhoven,et al.  TimeStats: A Software Tool for the Retrieval of Temporal Patterns From Global Satellite Archives , 2011, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.

[81]  M. Herold,et al.  Tracking disturbance-regrowth dynamics in tropical forests using structural change detection and Landsat time series , 2015 .

[82]  K. Moffett,et al.  Remote Sens , 2015 .

[83]  R. Preisendorfer,et al.  Principal Component Analysis in Meteorology and Oceanography , 1988 .

[84]  S. Goddard,et al.  A Self-Calibrating Palmer Drought Severity Index , 2004 .

[85]  D. R. Jones,et al.  Corresponding author address: , 2002 .

[86]  Kenji Omasa,et al.  MODIS vegetation and water indices for drought assessment in semi-arid ecosystems of Iran , 2009 .

[87]  Xuefeng Cui,et al.  Drought: The most important physical stress of terrestrial ecosystems ☆ , 2014 .

[88]  Sandrine Chauchard,et al.  An increase in the upper tree-limit of silver fir (Abies alba Mill.) in the Alps since the mid-20th century: a land-use change phenomenon. , 2010 .

[89]  Christian Körner,et al.  Drought-sensitivity ranking of deciduous tree species based on thermal imaging of forest canopies , 2011 .

[90]  G. Bonan.  Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests , 2008, Science.