The plants, especially woody, are capable to occlude many industrial discharging components [1]. Therefore ecological evaluation of territories can be conducted by firtree needle properties. An ecological state of forest ecosystem is evaluated using physiological parameters [2]. However in the known publications deliquification and water retention ability of firtree needles are unsufficiently investigated and the estimated parameters as applied to diagnostics of pollution about a firtree habitat are not developed.
The purpose of the given article  to show approach of firtree needle desiccation regularities analysis, and basis of this analysis to enunciate a technique of ecological firtree habitat evaluation.
For consummation this purpose problems sequentially were decided:
1) the statistical characteristics of desiccation process by cut firtree ramuluses were determined;
2) using methods of statistical modelling [4], model of the water retention by firtree needles process was developed;
3) theoretically availability of ramule deliquification parameters for ecological monitoring realization was justified.
For an environmental investigation of territory the firtrees Picea аbies [3] were taken. For experiments small firtrees at the age of 1215 were taken. Investigations were conducted on territory of scientificexperimental forestry enterprise of Mari state technical university: 46 compartment, 1 subcompartment (distance from a autoroad more than 50 meter).
From each small firtree from fourth verticil counting from above firtree, from four cardinal directions one ramule was collected from tip of lateral wings, then one lateral wing from northern cardinal direction was sniped about a stick.
In a fig. 1 two projections of a firtree are represented, from which control samples were collected (front elevation and top view).
As it is visible in a fig. 1, lateral wings, and also ramules are assembled in verticils. In a fig. 2 wing from which have sniped ramule R0 for realization of experiment is represented.
As it is visible in a fig. 2 for realization of experiment only central ramule was sniped.
Samples were packed in paper packets, on which number of a tree, cardinal direction, and also time of sample snipping were fixed.
Ramules were weighed at intervals of an hour the after snipping in laboratory on laboratory scales ELB 600 to within 0,05 g. The next weighings were completed in every three hours per the first day, in the next some day  23 times in the day, and then during two weeks  once in day and further once per one week.
In table 1 the obtained statistical data of desiccation by ramules of a firtree № 1 after snipping in four cardinal direction are represented.
Fig. 1. A firtree, from which control samples were collected
Table 1. Dynamics of desiccation by verticil tips of a firtree № 1
Interval, days 
Ramule mass, g 
Interval, days 
Ramule mass, g 

South 
North 
West 
East 
South 
North 
West 
East 

0,04 
1,45 
1,00 
1,00 
1,05 
11,00 
0,70 
0,45 
0,40 
0,50 
0,17 
1,35 
1,00 
0,95 
1,00 
12,00 
0,70 
0,45 
0,45 
0,50 
0,29 
1,30 
0,95 
0,90 
0,95 
13,00 
0,65 
0,45 
0,45 
0,45 
0,42 
1,30 
0,95 
0,90 
0,95 
14,00 
0,65 
0,45 
0,45 
0,45 
0,54 
1,30 
0,95 
0,90 
0,90 
15,00 
0,65 
0,45 
0,45 
0,45 
0,67 
1,25 
0,95 
0,85 
0,90 
15,00 
0,65 
0,45 
0,45 
0,45 
0,79 
1,25 
0,90 
0,85 
0,90 
18,00 
0,65 
0,45 
0,40 
0,45 
0,92 
1,25 
0,90 
0,85 
0,90 
20,00 
0,65 
0,45 
0,40 
0,45 
1,04 
1,25 
0,90 
0,85 
0,90 
22,00 
0,65 
0,45 
0,40 
0,45 
1,17 
1,25 
0,90 
0,80 
0,85 
25,00 
0,65 
0,45 
0,45 
0,45 
1,79 
1,20 
0,85 
0,75 
0,80 
27,00 
0,65 
0,45 
0,45 
0,45 
2,14 
1,15 
0,80 
0,75 
0,80 
29,00 
0,60 
0,40 
0,45 
0,45 
3,79 
1,00 
0,70 
0,65 
0,70 
35,00 
0,65 
0,45 
0,45 
0,45 
4,00 
1,00 
0,70 
0,65 
0,70 
36,00 
0,65 
0,45 
0,45 
0,45 
5,00 
0,95 
0,65 
0,60 
0,65 
43,00 
0,65 
0,40 
0,40 
0,45 
6,00 
0,90 
0,60 
0,55 
0,60 
55,00 
0,60 
0,45 
0,45 
0,45 
8,00 
0,80 
0,50 
0,45 
0,50 
63,00 
0,65 
0,45 
0,45 
0,45 
9,00 
0,75 
0,50 
0,50 
0,50 





Fig. 2. Ramule R0
On experimental data the formulas of a sample mass variation were obtained, the graphs of air drying are constructed by dint of software envelope Curve Expert  1.3.
From the southern cardinal direction the model of desiccation by ramule, sniped from lateral wing tip of firtree № by the procedure [5] the form:
, (1)
where m  mass of sample in the course of air drying process, g;
m_{m}  variable mass of moisture, which is lost by sample, g;
m_{d}  constant mass dry needles with ramule inclusive of their airdry moisture, g;
t  air drying time from the moment of sample snipping, day.
The formula (1) shows, that a model of firtree ramule air drying process has two components. First component m_{m} shows, that air drying process occurs by the death distribution in the general form, and second component m_{d}  that desiccation will occur up to some constant value of sample moisture mass.
In a fig. 3 the graph of desiccation by cut ramule of firtree № 1 is represented.
Fig. 3. The graph of desiccation by cut ramule of firtree № 1
Fig. 4. The residuals or absolute errors of a statistical cut firtree ramule air drying model
As it is visible in a fig. 3 during desiccation by ramules of firtrees moisture mass in test samples decreases, however deliquification rate is gradually reduced. The residuals or absolute errors of a statistical cut firtree ramule air drying model are represented in a fig. 4.
In a fig. 4 it is visible, that the residuals are almost equal to 0,025 g, that speaks about high model adequacy. The adequacy of the deduced statistical model is equal to 6,31 % and, accordingly, probability belief of the formula  93,69 %. Thus, the given formula of a statistical model can be applied for longterm forecasting [5].
The models of desiccation by ramules of firtree № 1 from northern cardinal direction, western cardinal direction and eastern cardinal direction, and also the models of desiccation by ramules of other firtrees have a similar character. The differences in moisture mass in tests from the all cardinal directions, the differences in activity and intensity of air drying of ramule tests, and also the differences in first passage time of constant mass by tests during air drying were revealed.
As it is visible from the formula (1), after reaching the certain time the test mass becomes a constant. Because of the model has a high probability belief, it is possible theoretically to calculate a first passage time of a constant ramule mass and initial moisture mass in ramule test m_{m0}.
In a fig. 5 the scheme of process of water retention by firtree ramule is shown.
Fig. 5. The water retention process scheme
The square designated on the scheme by cection lining, shows dynamics of decrease of ramule mass, and it is equal to:
, (2)
where S_{wr}  test water retention significance, or moisture mass in ramule test, g;
m_{m0}  initial moisture mass in ramule test, g;
m_{d}  constant mass of dry residues, g;
a_{1}  model parameter, indicating activity of air drying of test;
a_{2}  model parameter, indicating intensity of air drying of test.
For all control samples mean deliquification rate was estimated on formula:
, (3)
where V  mean deliquification rate, g/day;
t  the first passage time of ambient air  dry mass m_{d}, days.
In table 2 the deliquification rates of firtree ramules during air drying of all ramules for four firtrees are represented.
Table 2. Mean deliquification rate of tests
Number of firtree 
Mean deliquification rate, g/day 

South 
North 
West 
East 

1 
0,028 
0,038 
0,042 
0,028 
2 
0,040 
0,035 
0,036 
0,036 
3 
0,040 
0,030 
0,037 
0,057 
4 
0,039 
0,035 
0,037 
0,040 
mean 
0,03675 
0,0345 
0,038 
0,04025 
In a fig. 6 a histogram of significances of a deliquification rate of ramules from the all cardinal directions for each firtree are represented.
Fig. 6. Mean deliquification rate of firtree ramules
For comparison of obtained data Student´s test for want of 5percentage significance point was used. In table 3 the data of a comparison of deliquification rate of firtree ramules, cut from southern cardinal direction and northern cardinal direction are represented.
Table 3. Mean deliquification rate of ramules cut from northern cardinal direction and southern cardinal direction
Parameter 
South 
North 
Student´s test 
Significance point 
Deliquification rate 
0,037 
0,035 
0,67 
0,53 
From table 3 it is visible, that both samplings among themselves have not significant differences (for want of significance point more than 0,05).
For comparison of significances of deliquification rate of ramules cut from other cardinal directions the similar findings were obtained. The process of desiccation by ramules of firtree verticils occurs by law of decreasing up to a constant mass, and on which it is possible to define differences on ecological conditions of firtree habitat. The further analysis has shown, that the process air drying has wave constituents, which allow to estimate influence of the hydrometeorological factors of an experiment realization place.
Feature of novelty of an offered method is:
At first, the firtree ramule air drying method allows to reveal a general tendency of desiccation process by cut firtree ramules;
Secondly, the use of processes statistical modelling methods rather than mathematical allows to define statistical performances of drying process such, as an initial moisture mass in tests, constant a mass of dry test residues, first passage time of a constant mass;
Thirdly, use of a parameter of mean deliquification rate of control samples allows to define persistence of firtrees, and on persistence  ecological conditions of firtree habitat.
The positive effect consists that the revealed statistical regularities of desiccation process вy firtree ramules will allow to operate wood plantations of firtrees, to determine their persistence, and also ecological relations on investigated wood territories. Because of the firtree well adapts in urban environment, including a high level of pollution, the use of statistical given process regularities for ecological monitoring of urban environment is possible. The simplicity of an approach consists also that the measurements can be conducted on accountable trees, not carrying through harvesting of experimental trees.
References
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 Demakov, U.P. Plant protection. Sustainability and persistence of wood plants: Text edition / U.P. Demakov.  YoshcarOla: МаrGTU, 2002.  76 p.
 Kazimirov, N.I. A firtree / N.I. Каzimirov.  M.: forestry, 1983.  80 p.
 Mazurkin, P.M. Mathematical modelling. Identification of onefactor statistical regularities: Text edition / P.M. Mazurkin, A.S. Filonov.  YoshcarOla: МаrGTU, 2006.  292 p.
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