Correlations among leaf structure, drought tolerance and photosynthetic capacity in saplings of Euphorbiaceae from different micro-habitats in a seasonal tropical rainforest

doi:10.3724/SP.J.1258.2014.00028

Abstract

Abstract:

Aims Leaf structural and functional traits have been extensively studied to explain community assembly mechanisms, species distributions, niche differentiations, and even ecosystem services functions. However, these traits are influenced by both environment and phylogeny, showing correlations or trade-offs among them. In this study, we assessed the impacts of leaf structure on drought tolerance and photosynthetic potential, and the trade-off between drought tolerance and photosynthetic capacity, to provide an explanation for species coexistence and the maintenance of high biodiversity in tropical rainforests.
Methods We chose 18 species in the Euphobiaceae family differing in distribution patterns along topographic gradients in a 20 hm² forest dynamics monitoring plot (FDP) in Xishuangbanna. We measured leaf anatomy, leaf water relations characteristics, maximum photosynthetic rate, and dark respiration, and used two different methods—the traditional Pearson correlation and phylogenetic independent contrasts—to analyze the relationships among those traits.
Important findings We found that: 1) species showed convergence in structures and functions within specific habitat; species on ridge or slope had a stronger water loss-tolerance abilities than species in the valley. 2) Correlations among some key traits (specifically, leaf density, water potential at turgor loss point, and water potential at full turgor, etc.) were found among habitats; plants adjusted leaf structure to influence simultaneously plant water loss-tolerance abilities and photosynthetic capability, which may result in a trade-off between drought tolerance (high leaf density, leaf mass per area) and photosynthetic capability (low leaf density, leaf mass per area). 3) The phylogenetic independent contrasts must be used when analyzing correlations among the traits of genetically related species due to the weakness of traditional Pearson analysis. The ecological niche differentiation to water and light gradients as revealed by the present study provides a potential explanation for the high diversity of the seasonal tropical rainforest.

Key words: dark respiration, habitat, leaf structure, photosynthesis, pressure-volume curve

SUN Shan-Wen, ZHANG Yong-Jiang, CAO Kun-Fang. Correlations among leaf structure, drought tolerance and photosynthetic capacity in saplings of Euphorbiaceae from different micro-habitats in a seasonal tropical rainforest[J]. Chin J Plant Ecol, 2014, 38(4): 311-324.

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Figures/Tables 10

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种 Species	分布 Distribution	丰度 Abundance (Ind.·hm^-2)
长梗三宝木 Trigonostemon thyrsoideus	沟谷 Valley	40.45
粉绿野桐 Mallotus garrettii	沟谷 Valley	34.15
勐腊核果木 Drypetes hoaensis	沟谷 Valley	28.35
棒柄花 Cleidion brevipetiolatum	沟谷 Valley	48.55
秋枫 Bischofia javanica	沟谷 Valley	1.65
缅桐 Sumbaviopsis albicans	山坡 Slope	23.00
轮叶戟 Lasiococca comberi	山坡 Slope	9.20
风轮桐 Epiprinus siletianus	山坡 Slope	6.20
网脉核果木 Drypetes perreticulata	山坡 Slope	1.50
土蜜树 Bridelia tomentosa	山坡 Slope	1.05
木奶果 Baccaurea ramilflora	遍及整个样地 Throughout the entire sample plot	160.60
山地五月茶 Antidesma montanum	遍及整个样地 Throughout the entire sample plot	22.75
日本五月茶 Antidesma japonicum	遍及整个样地 Throughout the entire sample plot	13.75
尾叶血桐 Macaranga kurzii	山脊 Ridge	0.40
越南巴豆 Croton kongensis	山脊 Ridge	7.35
银背巴豆 Croton argyratus	山脊 Ridge	3.00
椴叶山麻杆 Alchornea tiliifolia	山脊 Ridge	18.75
云南银柴 Aporusa yunnanensis	山脊 Ridge	26.40

种 Species	分布 Distribution	丰度 Abundance (Ind.·hm^-2)
长梗三宝木 Trigonostemon thyrsoideus	沟谷 Valley	40.45
粉绿野桐 Mallotus garrettii	沟谷 Valley	34.15
勐腊核果木 Drypetes hoaensis	沟谷 Valley	28.35
棒柄花 Cleidion brevipetiolatum	沟谷 Valley	48.55
秋枫 Bischofia javanica	沟谷 Valley	1.65
缅桐 Sumbaviopsis albicans	山坡 Slope	23.00
轮叶戟 Lasiococca comberi	山坡 Slope	9.20
风轮桐 Epiprinus siletianus	山坡 Slope	6.20
网脉核果木 Drypetes perreticulata	山坡 Slope	1.50
土蜜树 Bridelia tomentosa	山坡 Slope	1.05
木奶果 Baccaurea ramilflora	遍及整个样地 Throughout the entire sample plot	160.60
山地五月茶 Antidesma montanum	遍及整个样地 Throughout the entire sample plot	22.75
日本五月茶 Antidesma japonicum	遍及整个样地 Throughout the entire sample plot	13.75
尾叶血桐 Macaranga kurzii	山脊 Ridge	0.40
越南巴豆 Croton kongensis	山脊 Ridge	7.35
银背巴豆 Croton argyratus	山脊 Ridge	3.00
椴叶山麻杆 Alchornea tiliifolia	山脊 Ridge	18.75
云南银柴 Aporusa yunnanensis	山脊 Ridge	26.40

性状 Trait	山脊 Ridge	山坡 Slope	沟谷 Valley	广布种 Cosmopolitan species
SWC (%)	2.660 ± 0.840^ab	1.860 ± 0.330^a	3.280 ± 1.110^ab	4.260 ± 0.770^b
π_o (MPa)	-1.670 ± 0.180^a	-1.740 ± 0.250^a	-1.190 ± 0.220^b	-1.190 ± 0.040^b
π_tlp (MPa)	-1.950 ± 0.180^a	-1.990 ± 0.220^a	-1.400 ± 0.270^b	-1.400 ± 0.020^b
ε (MPa)	15.21 ± 6.540^a	22.32 ± 7.480^a	18.70 ± 6.300^a	11.88 ± 2.190^a
RWC_tlp (%)	84.62 ± 5.280^a	90.70 ± 4.600^ab	92.61 ± 3.560^b	86.99 ± 0.810^ab
LT (mm)	0.670 ± 0.380^a	0.540 ± 0.140^a	0.900 ± 0.300^a	1.100 ± 0.460^a
UET (mm)	0.069 ± 0.036^a	0.061 ± 0.010^a	0.083 ± 0.017^a	0.164 ± 0.053^b
PT (mm)	0.240 ± 0.130^a	0.150 ± 0.060^a	0.190 ± 0.090^a	0.280 ± 0.060^a
ST (mm)	0.300 ± 0.230^a	0.260 ± 0.100^a	0.540 ± 0.220^a	0.550 ± 0.340^a
LET (mm)	0.063 ± 0.022^a	0.063 ± 0.015^a	0.080 ± 0.018^a	0.101 ± 0.023^a
P/S (%)	1.214 ± 0.611^a	0.670 ± 0.345^a	0.432 ± 0.270^a	0.618 ± 0.208^a
LD (g·cm^-3)	940.4 ± 391.2^ab	1 175.0 ± 385.5^a	514.2 ± 94.2^b	529.5 ± 171.1^ab
LMA (g·cm^-2)	51.36 ± 12.810^a	59.56 ± 14.080^a	44.91 ± 14.750^a	53.49 ± 6.640^a
A_a (μmol·m^-2·s^-1)	10.380 ± 2.310^a	8.400 ± 3.410^a	7.690 ± 1.520^a	7.710 ± 0.750^a
A_m (nmol·g^-1·s^-1)	0.210 ± 0.150^a	0.160 ± 0.110^a	0.190 ± 0.110^a	0.150 ± 0.030^a
R (μmol·m^-2·s^-1)	0.600 ± 0.074^a	0.470 ± 0.074^b	0.500 ± 0.064^ab	0.480 ± 0.046^ab
R_m (nmol·g^-1·s^-1)	0.012 ± 0.003^a	0.008 ± 0.003^a	0.012 ± 0.006^a	0.009 ± 0.001^a

性状 Trait	山脊 Ridge	山坡 Slope	沟谷 Valley	广布种 Cosmopolitan species
SWC (%)	2.660 ± 0.840^ab	1.860 ± 0.330^a	3.280 ± 1.110^ab	4.260 ± 0.770^b
π_o (MPa)	-1.670 ± 0.180^a	-1.740 ± 0.250^a	-1.190 ± 0.220^b	-1.190 ± 0.040^b
π_tlp (MPa)	-1.950 ± 0.180^a	-1.990 ± 0.220^a	-1.400 ± 0.270^b	-1.400 ± 0.020^b
ε (MPa)	15.21 ± 6.540^a	22.32 ± 7.480^a	18.70 ± 6.300^a	11.88 ± 2.190^a
RWC_tlp (%)	84.62 ± 5.280^a	90.70 ± 4.600^ab	92.61 ± 3.560^b	86.99 ± 0.810^ab
LT (mm)	0.670 ± 0.380^a	0.540 ± 0.140^a	0.900 ± 0.300^a	1.100 ± 0.460^a
UET (mm)	0.069 ± 0.036^a	0.061 ± 0.010^a	0.083 ± 0.017^a	0.164 ± 0.053^b
PT (mm)	0.240 ± 0.130^a	0.150 ± 0.060^a	0.190 ± 0.090^a	0.280 ± 0.060^a
ST (mm)	0.300 ± 0.230^a	0.260 ± 0.100^a	0.540 ± 0.220^a	0.550 ± 0.340^a
LET (mm)	0.063 ± 0.022^a	0.063 ± 0.015^a	0.080 ± 0.018^a	0.101 ± 0.023^a
P/S (%)	1.214 ± 0.611^a	0.670 ± 0.345^a	0.432 ± 0.270^a	0.618 ± 0.208^a
LD (g·cm^-3)	940.4 ± 391.2^ab	1 175.0 ± 385.5^a	514.2 ± 94.2^b	529.5 ± 171.1^ab
LMA (g·cm^-2)	51.36 ± 12.810^a	59.56 ± 14.080^a	44.91 ± 14.750^a	53.49 ± 6.640^a
A_a (μmol·m^-2·s^-1)	10.380 ± 2.310^a	8.400 ± 3.410^a	7.690 ± 1.520^a	7.710 ± 0.750^a
A_m (nmol·g^-1·s^-1)	0.210 ± 0.150^a	0.160 ± 0.110^a	0.190 ± 0.110^a	0.150 ± 0.030^a
R (μmol·m^-2·s^-1)	0.600 ± 0.074^a	0.470 ± 0.074^b	0.500 ± 0.064^ab	0.480 ± 0.046^ab
R_m (nmol·g^-1·s^-1)	0.012 ± 0.003^a	0.008 ± 0.003^a	0.012 ± 0.006^a	0.009 ± 0.001^a

	SWC	π_o	π_tlp	ε	RWC_tlp	LT	UET	PT	ST	LET	P/S	LD	LMA	A_a	A_m	R	R_m
SWC	1	0.81^***	0.82^***	-0.25	0.07	0.62^**	0.61^**	-0.05	0.70^**	0.60^*	-0.81^***	-0.71^***	-0.44	0.25	0.51^*	0.19	0.57^*
π_o	0.70^**	1	0.98^***	-0.25	0.20	0.59^*	0.52^*	-0.23	0.74^***	0.37	-0.76^***	-0.71^***	-0.86^***	0.27	0.63^**	-0.11	0.66^**
π_tlp	0.77^***	0.98^***	1	-0.20	0.28	0.55^*	0.53^*	-0.24	0.69^**	0.41	-0.82^***	-0.70^**	-0.79^***	0.18	0.57^**	-0.17	0.61^**
ε	-0.47	-0.68^**	-0.57^*	1	0.81^***	-0.65^**	-0.45	0.01	-0.74^***	-0.44	0.43	0.24	0.66^**	-0.65^**	-0.74^***	-0.37	-0.69^**
RWC_tlp	-0.05	-0.26	-0.10	0.77^***	1	-0.31	-0.18	-0.05	-0.34	-0.06	-0.12	-0.13	0.47	-0.56^*	-0.54^*	-0.44	-0.52^*
LT	0.64^**	0.60^**	0.60^**	-0.13	0.25	1	0.84^***	0.74^***	0.95^***	0.91^***	-0.56^*	-0.78^***	0.33	0.01	-0.25	-0.03	-0.33
UET	0.66^**	0.55^*	0.56^*	-0.31	0	0.71^**	1	0.71^***	0.69^**	0.85^***	-0.45	-0.62^**	0.23	-0.06	-0.23	-0.10	-0.28
PT	0.65^**	0.42	0.43	-0.23	-0.06	0.51^*	0.27	1	0.49^*	0.69^**	0.20	-0.61^**	0.23	0.40	0.05	0.36	-0.08
ST	0.50^*	0.56^*	0.55^*	-0.03	0.37	0.95^***	0.66^**	0.23	1	0.82^***	-0.70^**	-0.73^***	0.32	-0.13	-0.33	-0.17	-0.37
LET	0.54^*	0.52^*	0.54^*	-0.20	0.20	0.83^***	0.63^**	0.60^*	0.71^**	1	-0.50^*	-0.76^***	0.34	-0.03	-0.25	-0.16	-0.38
P/S	-0.21	-0.37	-0.37	-0.37	-0.68^**	-0.54^*	-0.30	-0.00	-0.70^**	-0.57^*	1	0.69^**	0.44	-0.21	-0.45	0.06	-0.41
LD	-0.70^**	-0.89^***	-0.87^***	0.75^***	0.36	-0.75^**	-0.56^*	-0.10	-0.81^***	-0.60^*	0.48^*	1	0.76^***	-0.53^*	-0.81^***	-0.23	-0.82^***
LMA	-0.16	-0.29	-0.27	0.31	0.33	-0.29	-0.24	0.40	-0.47	0	-0.37	0.14	1	-0.22	-0.77^***	0.16	-0.75^**
A_a	0.16	0	-0.04	-0.39	-0.42	0.69^**	0.22	0.58^*	0.61^**	0.54^*	0.35	-0.20	-0.28	1	0.77^***	0.76^***	0.44
A_m	0.14	0.10	0.10	-0.37	-0.37	0.60^*	0.27	0.18	0.62^**	0.40	0.44	-0.18	-0.68^**	0.80^***	1	0.49^*	0.87^***
R	0.20	-0.08	-0.14	-0.41	-0.56^*	0.53^*	0.10	0.70^**	0.38	0.52^*	0.48^*	-0.18	-0.24	0.59^**	0.52^*	1	-0.62^**
R_m	0.16	0.12	0.12	-0.36	-0.40	0.50^*	0.25	0.04	0.56^*	0.30	0.49^*	-0.15	-0.86^***	0.58^*	0.92^***	-0.45	1