Silva Fennica

Fig. 1. Location of the permanent research plots 1–5 (black dots) in which the pine stands were investigated.

Table 1. Overview of the basic characteristics of permanent research plots in 2015.
	Plot name	GPS	Age	Height	DBH	Volume	Altitude	Forest site type	Soil type
	Plot name	GPS	Age	m	cm	m³ ha^–1	m a.s.l.	Forest site type	Soil type
1	Třebechovice 1	50.202°45´N 16.059°01´E	90	21	27	410	267	1M7 - Pineto-Quercetum oligotrophicum arenosum	Dystric Arenic Cambisol
2	Třebechovice 2	50.196°27´N 16.056°46´E	80	23	27	380	260	0K1 - Querceto-Pinetum acidophilum	Dystric Arenic Cambisol
3	Třebechovice 3	50.196°80´N 16.056°97´E	80	26	21	300	260	0K1 - Querceto-Pinetum acidophilum	Podzol Arenic
4	Třebechovice 4	50.192°23´N 15.963°74´E	140	22	30	400	245	0M2 - Querceto-Pinetum oligotrophicum	Podzol Arenic
5	Třebechovice 5	50.193°34´N 15.961°96´E	130	24	28	430	245	0M2 - Querceto-Pinetum oligotrophicum	Podzol Arenic

Table 2. Overview of indices describing the stand structure and their common interpretation.
Criterion	Quantifiers	Label	Reference	Evaluation
Horizontal structure	Index of non-randomness	A (H&Si)	Hopkins, Skellam (1954)	mean value A = 0.5; aggregation A > 0.5; regularity A < 0.5
	Aggregation index	R (C&Ei)	Clark, Evans (1954)	mean value R = 1; aggregation R < 1; regularity R > 1
	Index of cluster size	CS (D&Mi)	David, Moore (1954)	mean value CS = 1; aggregation CS > 1; regularity CS < 1
Vertical diversity	Arten-profil index	Ap (Pri)	Pretzsch (2006)	range 0–1; balanced vertical structure Ap < 0.3; selection forest Ap > 0.9
Structure differen- tiation	Diameter dif.	TM_d (Fi)	Füldner (1995)	range 0–1; low TM < 0.3; very high differentiation TM > 0.7
	Height dif.	TM_h (Fi)	Füldner (1995)	range 0–1; low TM < 0.3; very high differentiation TM > 0.7
	Crown dif.	K (J&Di)	Jaehne, Dohrenbusch (1997)	minimum K = 0, higher K = higher values; low K < 1.5; high differentiation K > 2.5
Species diversity	Heterogeneity	H´ (Shi)	Shannon (1948)	minimum H´= 0, higher H´= higher values
Species diversity	Evenness	E (Pii)	Pielou (1975)	range 0–1; minimum E = 0, maximum E = 1
Complex diversity	Stand diversity	B (J&Di)	Jaehne, Dohrenbusch (1997)	monotonous structure B < 4; uneven structure B = 6–8; very diverse structure B > 9

Table 3. Detailed overview of stand characteristics of the tree layer on PRP 1–5 in 2005 and 2015.
PRP	Year	Age	dbh	h	v	N	BA	V	PAI	MAI	CC	CPA	SDI
PRP	Year	y	cm	m	m³	trees ha^–1	m² ha^–1	m³ ha^–1	m³ ha^–1 y^–1	m³ ha^–1 y^–1	%	ha	SDI
1	2005	68	25.8	19.90	0.536	644	33.5	345	8.0	4.42	80.2	1.62	0.66
1	2015	80	27.1	21.44	0.627	660	38.1	414	8.1	5.18	77.1	1.47	0.73
2	2005	59	26.3	21.33	0.531	644	35.1	342	7.5	4.96	80.2	1.61	0.70
2	2015	70	27.3	23.05	0.621	620	36.4	385	7.0	5.50	72.7	1.30	0.72
3	2005	59	24.7	19.76	0.455	656	31.5	299	8.0	4.33	80.2	1.62	0.65
3	2015	70	26.0	20.60	0.523	612	32.5	320	7.0	4.57	69.3	1.18	0.65
4	2005	120	31.2	22.63	0.798	472	36.2	377	6.5	2.90	76.2	1.44	0.68
4	2015	130	30.5	22.42	0.791	508	37.2	402	6.4	3.08	74.8	1.38	0.70
5	2005	117	26.4	22.40	0.564	728	39.9	410	8.5	3.23	81.1	1.67	0.80
5	2015	128	27.8	23.91	0.662	656	39.7	434	7.1	3.39	70.4	1.22	0.78
Age average stand age, dbh mean quadratic breast height diameter, h mean height, v average tree volume, N number of trees per hectare, BA basal area, V stand volume, PAI periodic annual increment; MAI mean annual increment, CC canopy closure, CPA crown projection area, SDI stand density index

Fig. 2. Diameter distribution on the permanent research plots (PRP) 1–5 converted per ha in 2005 and 2015.

Fig. 3. Relationship between the height and diameter for the permanent research plots (PRP) 1–5 in 2005 and 2015.

Table 4. Indices describing the structural, species and complex diversity of the tree layer on PRP 1–5 in 2005 and 2015.
PRP	Year	Indices
PRP	Year	R(C&Ei)	A(H&Si)	CS(D&Mi)	Ap(Pri)	TM_d(Fi)	TM_h(Fi)	K(J&Di)	H´(Si)	E(Pii)	B(J&Di)
1	2005	1.105	0.496	–0.048	0.400	0.349	0.304	2.809	0.163	0.271	8.022
1	2015	1.230*	0.402*	–0.469*	0.241	0.328	0.273	1.718	0.174	0.289	6.694
2	2005	1.248*	0.366*	–0.399*	0.333	0.219	0.107	1.034	0.081	0.269	4.500
2	2015	1.264*	0.350*	–0.604*	0.269	0.229	0.099	2.310	0.062	0.130	6.469
3	2005	1.198*	0.403*	–0.378*	0.407	0.289	0.191	1.486	0.145	0.241	6.211
3	2015	1.216*	0.427	–0.268	0.375	0.305	0.195	2.485	0.165	0.274	7.011
4	2005	1.225*	0.373*	–0.429*	0.360	0.204	0.091	2.692	0.001	0.003	6.454
4	2015	1.205*	0.419*	–0.271	0.322	0.307	0.187	1.706	0.012	0.025	5.791
5	2005	1.268*	0.345*	–0.496*	0.595	0.194	0.094	0.579	0.000	0.000	2.923
5	2015	1.308*	0.359*	–0.459*	0.216	0.205	0.074	0.615	0.000	0.000	2.449
R aggregation index, A index of non-randomness, CS index of cluster size, Ap Arten-profil index, TM_d diameter differentiation index, TM_h height differentiation index, K crown differentiation index, H´ index of species heterogeneity, E index of species evenness, B stand diversity index; *statistically significant for horizontal structure (P < 0.05)

Fig. 4. Horizontal structure of the forest stands in Třebechovice locality on the permanent research plots (PRP 1–5) in 2015.

Table 5. Numbers of recruits converted per ha, their percentage ratio and average height differentiated by tree species on the permanent research plots (PRP) 1–4.
Species	Year	PRP 1			PRP 2			PRP 3			PRP 4
Species	Year	recruits ha^–1	%	cm	recruits ha^–1	%	cm	recruits ha^–1	%	cm	recruits ha^–1	%	cm
Pinus sylvestris	2005	44	69	142	116	94	117	1284	99	138	1448	97	162
Pinus sylvestris	2015	304	89	306	724	98	237	4080	99	298	4732	96	326
Picea abies	2005	12	19	211	8	6	201	12	1	254	16	1	175
Picea abies	2015	36	10	371	12	2	421	40	1	420	32	1	380
Betula pendula	2005	4	6	-	0	0	-	4	0	245	24	2	182
Betula pendula	2015	0	0	-	0	0	-	4	0	435	176	3	392
Quercus petraea	2005	4	6	122	0	0	-	0	0	-	0	0	-
Quercus petraea	2015	4	1	210	0	0	-	0	0	-	0	0	-
∑	2005	64	100	147	124	100	118	1296	100	140	1492	100	167
∑	2015	344	100	312	736	100	240	4124	100	300	4940	100	330
On PRP 5 no natural regeneration in the study period was present

Fig. 5. Histograms of the height structure of natural regeneration on the permanent research plots (PRP) 1–4 differentiated by tree species and converted per ha in 2015.

Table 6. Indices describing the horizontal structure of natural regeneration on the permanent research plots (PRP) 1–4 in 2015.
Index	PRP 1	PRP 2	PRP 3	PRP 4
Hopkins–Skellam A	0.742*	0.923*	0.776*	0.890*
Clark–Evans R	0.627*	0.492*	0.783*	0.738*
David–Moore DM	3.652*	6.320*	4.140*	5.195*
* Statistically significant (P < 0.05)

Fig. 6. Spatial relations of natural regeneration and the tree layer on the permanent research plots (PRP) 1–4 represented by the pair correlation function; the black line depicts the pair correlation function g(r) for real distances between individuals on the permanent research plots (PRP); two grey curves illustrate the 95% confidence interval for the random spatial pattern; r – radius defining distance between the selected points (trees and nature regeneration); g(r) > 1 indicates a clustering at distances r, while g(r) < 1 indicates a regularity in the respective distances r.

Table 7. Chronologies characteristics including mean increment, Explained proportion of Signal (EPS) autocorrelation values before and after standardization and dendrometric characteristics of sampled trees on the permanent research plots (PRP) 1–5.
PRP	Mean increment (mm)	Explained proportion of signal	Autocorrelation value before standardization	Autocorrelation value after standardization	Length in age 80 (cm)	Min. dbh* (cm)	Max. dbh* (cm)	Min. height (m)	Max. height (m)
1	1.88516	0.874	0.7738	0.5116	11.38	24.2	33.3	24.9	27.5
2	1.65091	0.864	0.7481	0.5098	11.75	21.6	35.7	22.0	26.4
3	1.61937	0.685	0.7059	0.5577	11.40	20.0	36.7	20.4	25.5
4	1.07536	0.885	0.7123	0.6065	7.84	22.6	36.9	21.2	25.1
5	1.25056	0.879	0.7288	0.6109	8.46	24.1	36.4	24.8	26.9
* Breast height diameter without bark

Fig. 7. Average tree-ring series from the permanent research plots (PRP) 1–5 and in total after age detrending.

Fig. 8. The values of correlation coefficients of the regional standardized tree-ring chronology with the monthly temperature (left) and precipitation (right) from May of the previous year (P) to September of the current year for the period 1963–2014. Only correlation coefficients with statistically significant values (α = 0.05 %) are displayed.

Table 8. Correlations between radial growth increment with climatic data (1963–2014) and air pollution factors (1984–2014; AOT40F 1996–2014) and health status (2005–2014). Significant correlations (P < 0.05) are indicated in bold.

SO₂
mean

SO₂
veg

SO₂
nonveg

NO_x
mean

NO_x
veg

NO_x
nonveg

AOT40F

S
depos

N
depos

Temp ActAnn

Temp ActVeg

Temp
PrevVeg

Foliation

–0.66

–0.46

–0.29

–0.35

–0.24

–0.49

–0.45

–0.69

–0.01

0.08

0.60

Increment

0.17

0.11

0.22

0.42

0.19

0.04

0.37

0.24

0.27

–0.26

–0.34

–0.33

Temp ActV-VIII

Temp PrevV-VIII

Temp ActI-III

Temp Nonveg

Prec ActSum

Prec ActVeg

Prec PrevVeg

Prec ActV-VIII

Prec PrevV-VIII

Prec ActI-III

Prec Nonveg

Incre- ment

Foliation

0.50

0.71

0.13

–0.10

–0.15

–0.03

0.48

–0.13

0.63

–0.25

–0.12

0.88

Increment

–0.22

–0.29

–0.00

–0.87

0.17

0.01

0.17

–0.07

0.10

0.11

0.09

1.00

SO₂mean mean annual SO₂ concentration, SO₂veg mean SO₂ concentrations in vegetation season, SO₂nonveg mean SO₂ concentrations in nonvegetation season, NO_x, AOT40F ozone exposure, Sdepos annual S deposition, Ndepos annual N deposition, TempActAnn mean annual temperature, TempActVeg mean temperature in the current vegetation season, TempPrevtVeg mean temperature in the previous vegetation season, TempActV-VIII mean temperature in May–August of the given year, TempPrevV-VIII mean temperature in May–August of the previous year, TempActI-III mean temperature in January–March of the given year, TempNonveg mean temperature in the nonvegetation season; Prec sum of precipitation