monitoring the dynamics of vegetation components in...

David Helman and Itamar M. Lensky Bar-Ilan University

I thank Prof. S. Brenner and Prof. Y. Carmel for their helpful comments and pleased

by their willingness to assist and thus contribute to my PhD work in the future. The

changes I made in the research proposal following the comments are delineated

hereafter.

1. I corrected all phrases and spelling mistakes.

2. I added detailed information regard the SEBE with the relevant equations

therein (Chapter 1.2.1 – “The SEB method”, pages 9-10).

3. I added an explanation on the Structural Equation Modeling (SEM) in

Materials and Methods (Chapter 3.3 – “Software”, page 23).

4. I added information on the total size of Yatir forest area for comparison with

satellite resolution in Materials and Methods (Chapter 3.1 – “Remote sensing

data”, page 19).

Sincerely,

David Helman

Department of Geography and Environment

Bar Ilan University

From the 40th Annual Conference of the Israel Society of Ecology and Environmental Science (ISEES), Tel Aviv, October 2012

Monitoring the dynamics of vegetation components in Mediterranean forests:

Time-series analysis of satellite-derived NDVI

Implications for management

Pre-fire mapping of fire-risk Mapping the optimal grazing regime

Conservation and afforestation planning

Chlorophyll a

Chlorophyll b

Carotenoids

Photosynthesis

Rate

Absorption

100% 0%

100% 0%

NIR + Red NIR - Red

NDVI = -1 < NDVI < +1

The Normalized Difference Vegetation Index (NDVI)

1 0.8 0.6 0.4 0.2 0

Time [days]

Growing Senescence

NDVI TIME SERIES

ND

VI

NDVI time series describes well the vegetation's phenology  

Measuring plant phenology with NDVI

250   m

Satellite  

200 100 0

Precipitation

0.8 0.6 0.4 0.2 0

Time [days]

ND

VI

summer   winter  

Trees Trees

grasses

Soil Soil

SUMMER   WINTER  

summer   winter  

Safriel et al. (2010)

Pixel’s  complexity  – different contributions to NDVI

(fW)

�

grasses

Soil

Trees 1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

Decomposing NDVI time series into trees and grasses

NDVI = Trees + grasses + Soil (1)

NDVI = Trees + grasses + Soil Soil ≈ constant (1) (2)

(fw)

1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

�

grasses

Soil

Trees

Decomposing NDVI time series into trees and grasses

(fw)

1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

�

grasses

Soil

Trees

NDVI = Trees + grasses + Soil Soil ≈ constant (1) (2)

Decomposing NDVI time series into trees and grasses

(fw)

1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

NDVI’

�

grasses

Soil

Trees

NDVI’  = Trees + grasses (3)

Decomposing NDVI time series into trees and grasses

(fw)

1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

NDVI’

Plotting  the  minimum  NDVI’  during  the summer for the contribution of trees to NDVI (no grasses are present)

�

grasses

Soil

Trees

NDVI’  = Trees + grasses (3)

Decomposing NDVI time series into trees and grasses

(fw)

1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

NDVI’

�

grasses

Soil

Trees

NDVI’  = Trees + grasses (3)

Trees = NDVI’min (in summer)

(4)

Trees

Decomposing NDVI time series into trees and grasses

grasses = NDVI’    – Trees (5)

(fw)

grasses

1 0.8 0.6 0.4 0.2 0

Time

ND

VI

2005 2006 2007 2008

NDVI’

�

grasses

Soil

Trees

Trees = NDVI’min (in summer)

(4)

NDVI’  = Trees + grasses (3)

Trees

Decomposing NDVI time series into trees and grasses

Murray – Darling Basin Queensland

Y = 150 X – 22.5

Lu et al. (2003)

FPC −  Foliage Projection Cover (%)

FPC = a y NDVI + b

AVHRR 8 Km data

NDVImin = Soil (0% vegetation)

NDVImax = pixel of full vegetation (~100%)

Linear correlation between field measured data and NDVI from satellite  

NDVImax −  NDVImin FPC

NDVI Trees =

FPC can be estimated relatively:  

Roderick et al. (1999)

NDVI – The biophysical meaning

NDVI

מ"ק 0 1 2 3 4

כרמל­-דלית  א

עוספיה

אוניברסיטת  חיפה

  עשבונים  )חרוב  מצוי,  אלון  מצוי(עד  רחבי  עלים  ­-עצים  ירוקי  )אורן  ירושלים(עד  מחטניים  ­-עצים  ירוקי  חקלאות  קרקע

    )סירה  קוצנית(בני  שיחים    )אלת  המסטיק,  רתמה  קוצנית,  קידה  שעירה(שיחים 

Carmel et al. (2009)

בית  אורן

טירת  הכרמל טירת  הכרמל אוניברסיטת  חיפה

עוספיה

בית  אורן

ניות

כרמל­-דלית  א

ל    "כרם  מהר

ניות

(Before December 2010)

> +25 %

0

> -25 %

Carmel Forest – patterns of tree cover (2001-2010)

Decadal change in tree canopy cover [%]

טירת  הכרמל אוניברסיטת  חיפה

עוספיה

בית  אורן

כרמל­-דלית  א

ל    "כרם  מהר

ניות

> +25 %

0

> -25 %

Woody trend

Herbs

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

1.0

0.8

0.6

0.4

0.2

0

2006 Fire

(Before December 2010)

Carmel Forest – patterns of tree cover (2001-2010)

Decadal change in tree canopy cover [%]

טירת  הכרמל אוניברסיטת  חיפה

עוספיה

בית  אורן

כרמל­-דלית  א

ל    "כרם  מהר

ניות

> +25 %

0

> -25 %

Woody trend

Herbs

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

1.0

0.8

0.6

0.4

0.2

0

2006 Fire 2010 Fire

Carmel Forest – patterns of tree cover (2001-2010)

(Before December 2010)

Decadal change in tree canopy cover [%]

טירת  הכרמל אוניברסיטת  חיפה

עוספיה

בית  אורן

כרמל­-דלית  א

ל    "כרם  מהר

ניות

> +25 %

0

> -25 %

Woody trend

Herbs

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

1.0

0.8

0.6

0.4

0.2

0

2005 Fire

Carmel Forest – patterns of tree cover (2001-2010)

(Before December 2010)

Decadal change in tree canopy cover [%]

טירת  הכרמל אוניברסיטת  חיפה

עוספיה

בית  אורן

כרמל­-דלית  א

ל    "כרם  מהר

ניות

> +25 %

0

> -25 %

Decadal change in tree canopy cover [%]

Woody trend

Herbs

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

1.0

0.8

0.6

0.4

0.2

0

2010 Fire

Carmel Forest – patterns of tree cover (2001-2010)

(Before December 2010)

בית  אורן

טירת  הכרמל טירת  הכרמל אוניברסיטת  חיפה

עוספיה

בית  אורן

ניות

כרמל­-דלית  א

ל    "כרם  מהר

ניות

> +25 %

0

> -25 %

יער  נטוע   

Carmel Forest – patterns of tree cover (2001-2010)

(Before December 2010)

Decadal change in tree canopy cover [%]

ניר  עציון

חיפה  אוניברסיטת

ניות

טירת  הכרמל חיפה  אוניברסיטת

בית  אורןGrasses

Decadal change in annual grasses

> +35 %

0

> -35 %

Grazing areas map

ניר  עציון

בית  אורן

  ]2003[אשכנזי  .  ש  )ל"קק  –ממשק  הצומח  המעוצה  של  הכרמל  (

Carmel Forest – patterns of herbs cover (2001-2010)

(Before December 2010)

Paz S. et al. (2011)

בית  אורן

אוניברסיטת  חיפה טירת  הכרמל

ניות

חיפה  אוניברסיטת טירת  הכרמל טירת  הכרמל

חיפה  אוניברסיטת

בית  אורן בית  אורן

Trees Grasses

> +25 %

0

> -25 %

Decadal change in tree canopy cover

Decadal change in annual grasses

> +35 %

0

> -35 %

December 2010 wildfire on Mt. Carmel and Fire-risk map

ניר  עציון

ניר  עציון ניר  עציון

Carmel Forest – patterns of trees and grasses cover

Local Scale

1. Pre-fire mapping of fire-risk

2. Grazing management

3. Monitoring severe disturbances in forests (wildfires, tree

mortality etc.)

4. Monitoring biodiversity hotspots (vascular vegetation)

5. Climate change effect on forest structure

6. Patterns of change in vegetation in Mediterranean forests

7. Mapping climate-sensitive zones within the forests

Regional to global scale

Implications for management and research