A phenology-based method for monitoring woody and herbaceous vegetation in mediterranean forests from NDVI time series

David Helman*, Itamar M. Lensky, Naama Tessler, Yagil Osem

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

64 Scopus citations

Abstract

We present an efficient method for monitoring woody (i.e., evergreen) and herbaceous (i.e., ephemeral) vegetation in Mediterranean forests at a sub pixel scale from Normalized Difference Vegetation Index (NDVI) time series derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The method is based on the distinct development periods of those vegetation components. In the dry season, herbaceous vegetation is absent or completely dry in Mediterranean forests. Thus the mean NDVI in the dry season was attributed to the woody vegetation (NDVIW). A constant NDVI value was assumed for soil background during this period. In the wet season, changes in NDVI were attributed to the development of ephemeral herbaceous vegetation in the forest floor and its maximum value to the peak green cover (NDVIH). NDVIW and NDVIH agreed well with field estimates of leaf area index and fraction of vegetation cover in two differently structured Mediterranean forests. To further assess the method's assumptions, understory NDVI was retrieved form MODIS Bidirectional Reflectance Distribution Function (BRDF) data and compared with NDVIH. After calibration, leaf area index and woody and herbaceous vegetation covers were assessed for those forests. Applicability for pre- and post-fire monitoring is presented as a potential use of this method for forest management in Mediterranean-climate regions.

Original languageAmerican English
Pages (from-to)12314-12335
Number of pages22
JournalRemote Sensing
Volume7
Issue number9
DOIs
StatePublished - 2015
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2015 by the authors.

Keywords

  • LAI
  • MODIS
  • Mt. Carmel
  • Understory
  • Wildfire
  • Yatir

Fingerprint

Dive into the research topics of 'A phenology-based method for monitoring woody and herbaceous vegetation in mediterranean forests from NDVI time series'. Together they form a unique fingerprint.

Cite this