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ŠUMARSKI LIST 13/2005 str. 38     <-- 38 -->        PDF

PRESENTATION ATTHE INTERNATIONAL SYMPOSIUM
Šumarski list - SUPLEMENT (2005). 31-39


POSSIBILITIES OF MOUNTAIN FORESTS IN REDUCING
HIGH WATERS AND FLOODS


Petr KANTOR


SUMMARY: In the course of recent 8 years, the Czech Republic was affected
by three disastrous floods (July 1997, July 1998 and August 2002) induced
by extremely high precipitation particularly in mountain forested locations
of our country. The critique of causes and consequences of the devastating
flood situations in media did not avoid even forestry. Negative effects of
forest management on the intensity and extent of floods have been particularly
related to high reproduction cutting and unsuitable species composition of
our forests. The paper presented summarizes and comments findings obtained
from permanent experimental plots in the Orlicke hory Mts. On the example
of an uninterrupted series since 1977, water regime is comprehensively studied
of two main species of our mountain forests, viz spruce and beech. Data
are also available from all three floods. Results of the study unambiguously
show that spruce and beech forests effectively mitigate continuous precipitation
up to 100 mm. However, in precipitation exceeding 150 mm, the soil pro


file is quite saturated with water Then, uncontrolled and spontaneous runoff


occurs through the whole profile irrespective of the species composition of fo


rests or methods of regeneration.


INTRODUCTION


Forests occupy about 34 % of the area of the Czech spruce is usually presented in public media as a species
Republic. More than 50 % of precipitation falls on the which is unsuitable from the viewpoint of water manaforests.
It is not because forests "attract" water but simgement.
On the other hand, broadleaves are presented as
ply because upland and mountain locations with high species which can significantly contribute to the reducannual
precipitation totals amounting to 800 - 1500 mm tion of floods due to their high consumption of water.
show the highest forest percentage in our country. However, generally it refers to unsubstantiated opinions


and hypotheses lacking an actual evidence.


In the introduction of the paper it is necessary to
mention that during the last 200 years, the species comWhat
is a reality - is it possible to answer professioposition
of our forests has been markedly changed. nally a question indicated in the title of the paper?
While in the natural species composition, the percentage First, it is necessary to mention that it refers to an exof
conifers was only 34 % (of this Norway spruce 11 %), tremely complicated sphere of problems dealt with by
at present, their proportion is more than twofold, viz forest research for a period of more than 100 years.
77 % (of this Norway spruce 54 %). At the same time,


A BRIEF VIEW OF THE HISTORY OF
WATER-MANAGEMENT FOREST RESEARCH


The first systematic measurements of some pararied
out by Krutsch in the German Tharandt as early as
meters of the water regime of forest stands were car-1863(Delfs 1955).
However, an internationally famous paper of E n


*
Prof. Ing. Petr Kantor, CSc, Department of Forest Estagier
(1919) is cited even at present. In the study, wablishment
and Silviculture FFWT, MUAF in Brno, Zemedelska
ter regime and the course of runoff are compared in an


3, 613 00 Brno, Czech Republic
e-mail: kantor@mendelu.cz


unwooded and in a forested small watershed in the