Dr. ing. Cătălin-Constantin Roibu ing. Daniel Wenţel

Drd.ing. Bogdan-Mihai Negrea

International Symposium "Forest and Sustainable

Development" 2012

Symposium dedicated to the commemoration of the 100th birth

anniversary of Prof. Dr. Mihail PRODAN

Purpose:

This article aims a quantification and comparative analysis of

climate–tree relationship for spruce based on an altitudinal

transect in Lala Valley of the Rodna Mountains National Park.

Objectives:

O1 To develop dendrochronological series on spruce in the

Lala Valley for three altitudinal levels;

O2 To determine the pointer years for the three altitudinal

levels;

O3 quantification of the pluviometrical and thermic regime

over the growth processes for all altitudinal levels

sampled.

General view of Lala valley

The map of study area with distribution of the dendrochronological points on Lala

valley.

For each altitudinal level were extracted 2 growth samples per tree in an amount of 30 trees;

The annual tree rings were measured using the system LINTAB 6 in the biometrics laboratory of the Forestry Faculty;

TSAPwin program, with an accuracy of 0.001 mm was used; Also the crossdating of the growth series was realized with TSAPwin software and

COFECHA software; Standardization of the series was performed by applying a cubic spline function of

67%n criteria. Average series of standardized growth index was obtained through the biponderate mean (Cook and Kairiukstis, 1990);

The developed dendrochronological series, RES type indices, was obtained by removing the correlation;

The correlation between meteorological parameters and the dendrochronological series elaborated was made for individual values, from June the year before the tree ring formed to August current year when the ring was formed.

Quantifying of the climate model required use of the response functions method calculated with BootRes Pack software (The CRAN project).

There were made a number of three

dendrochronological series on the three

altitudinal levels:

- PALA-HA hight altitude spruce (1700 m),

- PALA-MA average altitude spruce (1400 m),

- PALA-LA low altitude spruce (1000 m).

Negative characteristic years

Negative characteristic years

Negative characteristic years

The connection between growth indexes and the average

temperature

1901-2009 reaction

Low altitude spruce reaction

6.1. Reaction of the low altitude spruce in 1901-2009 period.

Climate-tree correlation

Climate-tree correlation

Climate-tree correlation

7.1 Temporal stability of series PALA-HA, PALA-MA, PALA-LA

Moving correlation between growth indexes and June temperature.

Spatial correlation map between dendrochronological series and June temperature.

1901-2009 1901-1940 1950-2009

Spatial correlation map between dendrochronological series and June temperature.

1901-2009 1901-1940 1950-2009

Spatial correlation map between dendrochronological series and June temperature

1901-2009 1901-1940 1950-2009

There were identified years of great drought for all

three dendrocronological series in Lala valley.

-PALA-HA years 1913, 1948 ,2003,

-PALA-MA years 1913, 1929, 1948,

-PALA-LA years 1947, 2003,

Was shown the strong influence of the temperatures in

summer months (June, July) on the growth pattern of

Norway Spruce.

Was observed that the series of low altitude developed a total

different pattern of growth in dictate by June and July

temperature.

Through the correlation functions was determined that the growth

pattern of the spruce on low altitude was similar with the other

series but only until the forth decade of the last century.

Was analyzed the total different response of the low altitude

spruce reaching the conclusion that this fact is climatic

determinate, because of the extreme drought of the years 1946-

1947.

Also was shown the temporal stability of climate –growth

relationship (highlighted by the high correlation between growth

index and June, July temperature) at medium and high altitude.

A semnificative spatial correlation between the growth indexes and

the average temperature of June until year 1940 was made for the

dendrochronological series of medium and high altitude.

As a general conclusion has been highlighted that one climatic

major event (as “great drought” of 1946 year) not only

determinates the ring width in that year, but may change the

growth pattern (behavior) of a species at different altitudinal range.