Long-term changes in Mediterranean vegetation in Israel and California

Yohay CarmelYohay Carmel

Faculty of Agricultural EngineeringFaculty of Agricultural Engineering

The Technion -- Israel Institute of TechnologyThe Technion -- Israel Institute of Technology

Curtis FlatherCurtis Flather, Rocky Mountain Research Center, USDA Forest Service

Denis DeanDenis Dean, Department of Forest Sciences,Colorado State University

Ronen KadmonRonen Kadmon, Department of Ecology,

The Hebrew University of Jerusalem

A Cooperative Research:A Cooperative Research:

The Israel Forest Authority (KKL)

USDA Forest Service International Programs

Adult oaks (Quercus calliprinos) in Mt. Meron

Herbaceous vegetation in the front, recovering trees in the back, Mt. Meron

Earlier stages of recovery following land abandonment: dwarf shrubs, tall shrubs, and low trees in Mt. Meron

30 years after abandonment of pastoral cultivation in Mt. Meron

Mt. Meron 1945

Mt. Meron 1964

Mt. Meron 1992

Vegetation maps of Mt. Meron, Israel

Trees ShrubsHerbaceousVegetation

Factors that potentially Factors that potentially affect affect

current vegetation patterncurrent vegetation patternPast vegetation:Percentage cover of Trees, Shrubs, Herbaceous vegetation

•Disturbance Agents:•Grazing•Logging•Fire

Topography:• Slope• Aspect• Elevation

Soil

Map of the study area in Mt. Meron, showing the distinct plots of different grazing pressure, and the range of fire

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No grazing Low Moderate High

NoGrazing

Cattle

Goats

Change in Trees as a function of Grazing Pressure

Ch

ang

e in

tre

e co

ver

± S

EC

han

ge

in t

ree

cove

r ±

SE

Regression results Regression results for thefor the linear models linear models 11

NS - not significant * p<0.05 ** p<0.01 *** p<0.001

GROUP VARIABLE HERBACEOUS TREES

R2 = 0.54 R2 = 0.76

Constant 0.373* 1.127***

Disturbance MODCATTLE 0.066* -0.502*

HIGHCATTLE NS -0.496*

LOWGOAT NS NS

MODGOAT 0.302* -0.483*

LOGGING NS -0.357***

Regression results Regression results forfor thethe linear models linear models 22

NS - not significant * p<0.05 ** p<0.01 *** p<0.001

Group Variable Herbaceous Trees

1964 HERB64 NS -0.457**

Vegetation (HERB64)2 0.506** -0.388**

Topography ASPECT-NS 0.0015* NS

Variables ASPECT-EW -0.0015*** 0.003***

SLOPE NS 1.062**

ASPECT-NS*SLOPE -0.0034* -0.011**

Weight of predictors in affecting vegetation change in Mt. Meron

00.20.40.60.8

1

R2

Model input (1964 vegetation)Model input (1964 vegetation)

Actual 1992 vegetationActual 1992 vegetation

Predicted 1992 vegetationPredicted 1992 vegetation(Linear model)(Linear model)

MODELS AND REALIZATIONSMODELS AND REALIZATIONS

DETERMINISTIC REALIZATION

STOCHASTIC REALIZATION

WITH AUTOCOVARIATES

NO AUTOCOVARIATES

COMPLETE DATASET

SAMPLE DATASET

LOGISTIC MODEL

LINEAR MODEL

DeterministiDeterministic c

RealizationRealization

31%45%

24%

StochastiStochastic c

RealizatioRealizationn

????

??

!!

Stochastic Stochastic realizationrealization

Deterministic Deterministic realizationrealization

Actual and predictedproportions of 1992 vegetation

Actualvegetation

map

Deterministicrealization

Stochasticrealization

Trees 0.51 0.44 0.50

Shrubs 0.32 0.41 0.33

Herbs 0.17 0.15 0.16

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LIN/DET LOG/DET LOG/STOC

Model Area External Area

Matching the actual map on a cell by cell basis

Grazing intensitiesGrazing intensities do not changedo not change Grazing is excludedGrazing is excluded

Scenarios for 2020

Mediterranean type ecosystemsMediterranean type ecosystems

Guess if this photo was taken in Israel or in California

Oak woodland, chaparral, and grasses, in Carmel Valley, California

Precipitation patterns in California and Israel

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JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Pre

cipi

tati

on in

inch

es

ISR (Mt. Meron)

North CA (Cloverdale)

Central CA (Cachuma lake)

South CA (Cuyamaca)

Best match

Worst match

Precipitation match with Mt. Meron on a monthly basis

1. Cuyamaca mountains 2. Santa Ynez Mountains 4. Sequoia National Forest 5. Sierra Foothills Research Center 6. Hastings Natural History Reservation 8. South Cow Mountain

Hastings Nature Reserve, Carmel Valley, California

A small part of 1939 photo

Trees ChaparralGrassland

Same area in 1956

Same area in 1971

Same area in 1995

Vegetation maps of Hastings, California

Vegetation maps of Mt. Meron, Israel

Trees ShrubsHerbaceousVegetation

0%

1%

2%

3%

4%

All Withinreserve

Northslopes

Southslopes

Fire Initialtree

cover <0.1

An

nu

al r

ate

of

chan

ge

in t

ree

co

ve

r Hastings

Meron

Change in tree cover in Meron and Hastings

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Multipleregression

Pastvegetation

Topography Grazing, fire

HastingsMeron

Weight of predictors in affecting vegetation change

Mediterranean vegetation change in long-term, landscape-scale studies

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1%

2%

Ave

rage

an

nual

cha

nge

Why is there such a difference between vegetation dynamics

in California and the Mediterranean basin?

1. Local ecological and

anthropogenic conditions

2. Different soils

3. Different evolutionary historyDifferent evolutionary history

A transplant experiment is currently conducted, where oaks from both countries are grown

together in both sites, in a controlled environment

Carmel, Y. and Flather, C.H. 2004. Comparing landscape scale vegetation dynamics following recent disturbance in climatically similar sites in California and the Mediterranean basin. Landscape Ecology 19:573-590.

Carmel, Y., Kadmon R. and Nirel, R. 2001. Spatio-temporal predictive models of Mediterranean vegetation dynamics. Ecological Applications, 11 (1):268-280.

Carmel, Y. and Kadmon, R. 1999. Grazing, topography, and long term vegetation changes in a Mediterranean ecosystem. Plant Ecology, 145:239-250.

Carmel, Y. and Kadmon, R. 1998. Computerized classification of Mediterranean vegetation using panchromatic aerial photographs. Journal of Vegetation Science, 9:445-454.

Grunzweig, J.M., Carmel, Y., Riov, J. and Flather, C.H. Resource storage and adaptation to drought in oak seedlings: a comparative study with Californian and Mediterranean species. Submitted to Ecology.

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