Defining Holdridge's life zones over Turkey


TATLI H. , Dalfes H. N.

INTERNATIONAL JOURNAL OF CLIMATOLOGY, cilt.36, ss.3864-3872, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 36 Konu: 11
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1002/joc.4600
  • Dergi Adı: INTERNATIONAL JOURNAL OF CLIMATOLOGY
  • Sayfa Sayıları: ss.3864-3872

Özet

This study is proposing a classification for the Holdridge's life zones associated with the surface climatic variables over Turkey. Holdridge's scheme is aiming to group meteorological and climatic quantities at the regional scale according to some pre-defined rules. On the other hand, without rules or pre-defined restrictions, the process of combination of similar stations in groups is recognized as clustering. A spectral clustering method was suggested for identifying the characteristics of the local climate over the country. To increase the proxy value of the estimated life zones, the missing values in the data sets of temperature and precipitation series were filled by fitting appropriate theoretical variogram. A programme coded in Fortran 95 was developed for determining the life zones. The probabilistic features of the life zones were estimated by using empirical cumulative frequencies. In addition, a new spectral clustering method based on Sampson correlation ratio was developed for clustering high-dimensional data. From these results, four major categorical life zones were obtained, namely montane, lower montane, cool temperate and warm temperate. Additionally, 14 types of the Holdridge's vegetation classes were estimated, the frequent zones are cool temperate steppe and warm temperate dry forest; some moist forests are seen particularly in the eastern Black Sea region, the rainiest region of the country. The suggested spectral clustering method is capable of capturing the principal life zones. The tendency of life zones shifting towards the climate conditions of lower latitudes indicates that the long-term meteorological normals changed; this is exactly the point of climate change. A better understanding of life zones of Holdridge hopefully can contribute to sustainability plans of the policy makers.