Main drivers of vertical and seasonal patterns of leaf photosynthetic characteristics of young planted <i>Larix Olgensis</i> trees

Qiang Liu; Zhidong Zhang; Dongzhi Wang; Fengri Li; Longfei Xie; Qiang Liu; Zhidong Zhang; Dongzhi Wang; Fengri Li; Longfei Xie

doi:10.48130/fr-0023-0029

Figures (4) Tables (4)

Figure 1.
Vertical profiles of (a) light-saturated net photosynthetic rate (A_max); (b) light-saturated stomatal conductance (g_s-sat); (c) needle mass per area (NMA); (d) dark respiration (R_D); (e) ratio of length to width of needles (r_lw) and (f) light-saturated water use efficiency (WUE_sat). Data points represented seasonal mean values (solid bars represented stand error). Black solid line represented mean values of five sample trees (a)−(f).
Figure 2.
Seasonal evolution of (a) light-saturated net photosynthetic rate (A_max); (b) light-saturated stomatal conductance (g_s-sat); (c) needle mass per area (NMA); (d) dark respiration (R_D); (e) ratio of length to width of needles (r_lw) and (f) light-saturated water use efficiency (WUE_sat) for five sample trees. Data points represent seasonal mean values (solid bars represented stand error). Black solid line represented corrective mean values of five sample trees (a)−(f).
Figure 3.
Relationship between light-saturated net photosynthetic rate (A_max), light saturated stomatal conductance (g_s-sat), dark respiration (R_D), and light-saturated water use efficiency (WUE_sat) and (a), (d), (g), (j) leaf temperature (T_leaf); (b), (e), (h), (k) relative humidity (RH); and (c), (f), (i), (l) vapor pressure deficit (VPD) for five trees.
Figure 4.
Relationships between (a) light-saturated net photosynthetic rate (A_max) and needle mass per area (NMA); (b) light-saturated stomatal conductance (g_s-sat) and NMA; (c) dark respiration (R_D) and NMA; (d) light-saturated water use efficiency (WUE_sat) and NMA. R values are the Pearson correlation coefficients. Solid lines represent the fitting result and are based on linear equations.

Statistics	Net photosynthetic rate	Leaf trait	Environmental conditions			Spatial position
Statistics	A_n (μmol·m⁻²·s⁻¹)	LMA (g·m⁻²)	T_air (°C)	VPD (kPa)	PAR (μmol·m⁻²·s⁻¹)	RDINC
No.	9303					752
Mean	5.23	58.5	27.9	1.7	757	0.52
Std.	4.47	20.1	3.6	7	723	0.26
Max.	27.49	127.5	39.4	4.3	2200	0.99
Min.	−3.90	14.3	15.5	0.5	0	0.08
A_n, net CO₂ assimilation; LMA, leaf mass per area; T_air, air temperature; VPD, vapor pressure deficit; PAR, photosynthetically active radiation; RDINC, relative depth into the crown (RDINC). No., Mean, Std., Max. and Min. are the numbers, mean value, standard deviation, maximum value and minimum value, respectively.

Table 1.

Sample tree and data summary. Photosynthetic light response curves (752) were investigated, including 9303 instantaneous environmental and functional factors, from 36 pseudowhorls from five planted Larix olgensis trees.

Effects	df	A_max	g_s-sat	R_D	WUE_sat	NMA	r_lw
T	***	***	***	***	***	***	*
P	***	***	***	***	***	***	***
L	***	***	***	***	***	***	***
T×P	***	***	***	***	***	*	***
T×L	*	***	***	***	***	***
P×L	***	***	***	***	***	***	*
T×P×L	***	**	***		***
P, measurement period; T, tree specific; L, crown location. The different parameters have been identified and described in the text. , 0.01 < p ≤ 0.05; , 0.001 < p ≤ 0.01; **, p ≤ 0.001.

Table 2.

Results of the three-way repeated measures ANOVA of photosynthetic and morphological parameters.

Factors	Location	PI	PII	PIII	PIV	PV	PVI	PVII	PVIII
A_max (μmol·m⁻²·s⁻¹)	Upper	7.07 ± 0.18^a	8.67 ± 0.51^a	9.77 ± 0.89^a	12.11 ± 1.48^a	12.16 ± 0.74^a	14.18 ± 1.33^a	13.74 ± 1.42^a	11.42 ± 0.85^a
	Middle	6.76 ± 0.23^a	7.19 ± 0.66^b	7.82 ± 0.75^b	9.19 ± 0.82^b	9.03 ± 0.54^b	9.03 ± 1.24^b	8.11 ± 0.77^b	7.88 ± 0.38^b
	Lower	5.80 ± 0.12^b	5.93 ± 1.1^c	6.57 ± 0.78^c	6.03 ± 0.97^c	6.48 ± 1.07^c	5.15 ± 1.19^c	4.3 ± 1.71^c	5.47 ± 0.86^c
R_D (μmol·m⁻²·s⁻¹)	Upper	1.51 ± 0.12^a	1.35 ± 0.23^a	1.25 ± 0.12^a	1.13 ± 0.28^a	1.35 ± 0.25^a	1.36 ± 0.19^a	1.30 ± 0.15^a	1.46 ± 0.10^a
	Middle	1.37 ± 0.11^a	1.01 ± 0.25^b	0.96 ± 0.17^b	0.80 ± 0.18^b	0.66 ± 0.11^b	0.99 ± 0.23^b	0.90 ± 0.14^b	1.11 ± 0.14^b
	Lower	1.46 ± 0.03^a	0.74 ± 0.27^c	0.83 ± 0.20^b	0.65 ± 0.13^b	0.51 ± 0.10^b	0.96 ± 0.44^b	0.71 ± 0.20^c	1.04 ± 0.18^b
g_s-sat (mol·m⁻²·s⁻¹)	Upper	0.090 ± 0.01^a	0.117 ± 0.03^a	0.118 ± 0.01^a	0.164 ± 0.02^a	0.168 ± 0.02^a	0.297 ± 0.06^a	0.241 ± 0.05^a	0.223 ± 0.02^a
	Middle	0.074 ± 0.01^a	0.082 ± 0.02^b	0.089 ± 0.01^b	0.109 ± 0.01^b	0.114 ± 0.01^b	0.174 ± 0.04^b	0.125 ± 0.02^b	0.132 ± 0.02^b
	Lower	0.047 ± 0.01^b	0.058 ± 0.02^c	0.075 ± 0.02^c	0.078 ± 0.01^c	0.083 ± 0.02^c	0.117 ± 0.03^c	0.063 ± 0.02^c	0.085 ± 0.03^c
WUE_sat (mmol·mol⁻¹)	Upper	92.1 ± 9.6^a	93.3 ± 22.1^a	102.1 ± 11.4^a	79.7 ± 8.0^ab	76.0 ± 9.5^a	58.9 ± 8.1^b	61.1 ± 6.6^b	62.5 ± 3.8^a
	Middle	92.0 ± 7.2^a	91.0 ± 22.5^a	94.0 ± 7.0^a	84.2 ± 6.0^a	88.0 ± 9.3^a	69.5 ± 8.4^a	71.7 ± 12.3^a	63.9 ± 5.0^a
	Lower	113.7 ± 7.9^a	78.8 ± 14.3^a	93.6 ± 15.9^a	76 ± 12.8^b	88.4 ± 25.6^a	58.1 ± 16.4^b	57.1 ± 16.6^b	63.1 ± 13.4^a
NMA (g·m⁻²)	Upper	37.8 ± 1.5^a	58.6 ± 4.7^a	69.6 ± 5.0^a	74.5 ± 5.7^a	77.9 ± 6.0^a	91.7 ± 6.1^a	83.9 ± 6.1^a	74.6 ± 6.5^a
	Middle	36.4 ± 2.2^a	51.2 ± 4.5^b	53.9 ± 4.6^b	59.4 ± 5.6^b	56.7 ± 5.1^b	66.9 ± 5.3^b	60.8 ± 5.4^b	56.2 ± 5.4^b
	Lower	29.1 ± 1.1^a	35.9 ± 5.0^c	40.4 ± 5.7^c	42.9 ± 5.6^c	39.6 ± 5.6^c	45.6 ± 5.5^c	44.1 ± 5.5^c	40.8 ± 5.5^c
r_lw	Upper	14.2 ± 0.06^a	17.8 ± 0.10^a	18.6 ± 0.10^a	18.0 ± 0.08^a	17.7 ± 0.10^a	17.9 ± 0.11^a	17.4 ± 0.11^a	18.6 ± 0.12^a
	Middle	12.9 ± 0.07^b	15.7 ± 0.08^b	15.3 ± 0.08^b	15.2 ± 0.09^b	14.9 ± 0.08^b	14.4 ± 0.11^b	14.9 ± 0.09^b	16.2 ± 0.10^b
	Lower	11.5 ± 0.08^c	13.3 ± 0.11^c	13.3 ± 0.09^c	13.0 ± 0.10^c	13.5 ± 0.14^c	12.6 ± 0.10^c	12.9 ± 0.11^c	13.6 ± 0.11^c
Values are Mean ± SE. Mean values with same superscript do not differ significantly (p < 0.05).

Table 3.

Summary of physiological and morphological parameters in upper, middle, and lower crown, respectively during growing seasons.

Vertical layer	Photosynthetic parameters
Vertical layer	A_max	R_D	WUE_sat	g_s-sat
1	**		**	**
2	**		**	**
3	**		**	**
4	**		**	**
5		*
6		*
7		*
8		*
9		*
The different parameters have been identified and described in the text. , 0.01 < p ≤ 0.05; *, 0.001 < p ≤ 0.01.

Table 4.

Results of the One-way ANOVA of photosynthetic parameters in each vertical layer.