ISSN 1067-4136, Russian Journal of Ecology, 2017, Vol. 48, No. 2, pp. 109–115. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © V.N. Karasev, M.A. Karaseva, E.M. Romanov, D.I. Mukhortov, 2017, published in Ekologiya, 2017, No. 2, pp. 92–99.
Rapid Thermal Method for Early Diagnosis
of the Physiological State of Scots Pine Trees
V. N. Karasev, M. A. Karaseva, E. M. Romanov, and D. I. Mukhortov
Volga State University of Technology, Yoshkar-Ola, 424000 Russia
Received May 12, 2015
Abstract—Trends in stem temperature of Scots pine trees in different life states are described. Any substantial
disturbances of water flow in the roots, stem, or crown have an immediate effect on the stem temperature.
This temperature shows a strong inverse correlation with the state of the tree, with the coefficient of determi-
nation ranging from 0.710 to 0.974. The method of assessing the physiological state of trees by temperature
parameters allows early diagnosis of decline in the viability of conifers.
Keywords: Scots pine, diagnosis, physiology, information content, life state, rapid thermal method, bioelec-
tric potential, impedance measurement
Prognostic criteria used for assessing the life state
of plants and their tolerance to adverse environmental
factors include parameters of water regime [1–4],
enzyme activities , chlorophyll content [6–8], bio-
electric characteristics [9–14], and other parameters.
However, they do not always allow the life state of trees
at early stages of damage and deterioration to be eval-
uated in situ, directly in their natural environment.
The development of rapid methods for early diag-
nosis of the physiological state of trees is an urgent
problem. Its solution provides the possibility of taking
timely measures to maintain the ecological functions
of forests and improve their productivity.
The purpose of this study was to reveal the relation-
ship between the life state of Scots pine trees and
parameters their water regime and stem temperature,
develop a rapid method for early diagnosis of tree
physiological state based on thermal parameters, and
estimate its information content for trees with differ-
ent types of damage or deterioration.
MATERIAL AND METHODS
Integrates studies on basic physiological, bioelec-
tric, and morphometric parameters of trees were per-
formed in a lichen–moss Scots pine forest with a
stocking density of 0.6–0.7 (stand composition 10P)
on soddy-medium podzolic sandy soil, which was
affected by medium-intensity ground fire. The age of
trees was 40–50 years, their height and diameter aver-
aged 19 ± 0.6 m and 25 ± 1.0 cm.
With respect to the life state, trees were divided into
five groups: (1) undamaged, (2) moderately damaged,
(3) severely damaged, (4) dying, and (5) dead. This
was done with regard to the state of tree crowns and
European criteria for determining the class of tree
damage . Trees within each group were analyzed
for a set of parameters: the weight of remaining nee-
dles, their color, water flow rate, transpiration rate,
water expenditure, linear and weight parameters, and
moisture contents of wood and needles. These param-
eters were recorded in mid-July at 2 p.m.
The wet weight of needles per tree was determined
by complete census of five model trees of the same
diameter and type of damage from each life state
group, and thermal, bioelectric, and physiological
parameters were measured in ten model trees from
Transpiration rate was determined by the rapid
weighing method ; water content in the conduct-
ing xylem, in samples taken at breast height (1.3 m)
from trees of the same diameter from each life state
Water expenditure by trees was measured in two
ways: (a) as a function of needle weight per tree and
transpiration rate or (b) as a function of water content
per unit volume of conducting xylem and linear water
flow velocity, with correction for the area of water-
conducting zone of tree stem. Water flow velocity and
volumetric flow rate per unit xylem volume were mea-
sured at four points oriented in cardinal directions in
the middle part of water-conducting zone of the stem
at breast height.
Linear water flow velocity was measured by a rapid
conductimetric method ; total chlorophyll con-
tent, by a photoelectric colorimetric method .