Pressure-volume curve analysis of epiphytic lichens and its applicability in subtropical forests

doi:10.17521/cjpe.2020.0344

Abstract

Abstract:

Aims Epiphytic lichens are a widespread and significant component of forest ecosystems, and play an important role in biodiversity maintaining and water and nutrient cycling. This study aims to illustrate the water potential characteristics of the epiphytic lichen group and to assess whether the pressure-volume (PV) curve and relative parameters are suitable for exploring the response of lichens to drought stress.
Methods The water potential parameters and PV curves of 15 epiphytic lichen species from five functional groups were measured in the subtropical forests in the Ailao Mountains, Yunnan Province.
Important findings The internal water content (WC_internal) and symplast water content (Rs) of cyanolichens were significantly higher than those of chlorolichens, while other parameters showed no significant differences. We only observed significant differences in WC_internal, Rs and relative water content at turgor loss point (RWC_TLP) among different functional groups of lichens. All parameters differed significantly among species. Results of principal component analysis (PCA) further indicated that there are extensive limitations for PV curves and water potential parameters in evaluating the overall response of lichen species to water stress and in revealing the selection strategy of water-related habitats, largely due to the influence of the photobiont type and growth form. However, the adaptation strategies of cyanolichens to habitat could be explained by the maximum internal water holding capacity, while the adaptation to water conditions could be explained by the saturated water osmotic potential (Ψsat) in narrowly lobed foliose lichens, and by the RWC_TLP in broadly lobed foliose and fruticose lichens. Our study suggests that PV curves and water potential parameters are not suitable for the general evaluation of the drought resistance of lichen communities, and should be used carefully in comparing the drought resistances between lichens and other plant groups.

Key words: epiphytic lichen, water potential, internal water content, pressure-volume curve, principal component analysis, poikilohydric plant

DONG Lin-Lin, PU Xiao-Yan, ZHANG Lu-Lu, SONG Liang, LU Zhi-Yun, LI Su. Pressure-volume curve analysis of epiphytic lichens and its applicability in subtropical forests[J]. Chin J Plant Ecol, 2021, 45(3): 274-285.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2020.0344

https://www.plant-ecology.com/EN/Y2021/V45/I3/274

Figures/Tables 6

References 39

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物种 Species	共生藻型 Photobiont type	生长型 Growth form	功能群划分 Functional group	主要生境 Main habitat
网肺衣 Lobaria retigera (Lobret)	蓝藻 Cyanobacteria	叶状 Foliose	蓝藻型地衣 Cyanolichen (CYL)	阴湿至高光照湿润生境 Shaded to high-light and humid habitat
猫耳衣 Leptogium menziesii(Lepmen)	蓝藻 Cyanobacteria	叶状 Foliose	CYL	潮湿环境 Humid habitat
黑芽牛皮叶 Sticta fuliginosa(Stiful)	蓝藻 Cyanobacteria	叶状 Foliose	CYL	潮湿高光照生境 Humid and high-light habitat
针芽肺衣 Lobaria isidiophora(Lobisi)	绿藻 Green alga	阔叶型 Broadly lobed foliose	阔叶绿藻型地衣 Broadly lobed foliose chlorolichens (BFL)	中光至高光照生境 Medium to high-light habitat
网大叶梅 Parmotrema reticulatum (Parret)	绿藻 Green alga	阔叶型 Broadly lobed foliose	BFL	中光至高光照、潮湿生境 Medium to high-light, and humid habitat
平滑牛皮叶 Sticta nylanderiana (Stinyl)	绿藻 Green alga	阔叶型 Broadly lobed foliose	BFL	中光至高光照生境 Medium to high-light habitat
黑腹绵腹衣 Anzia hypomelaena (Anzhyp)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	狭叶绿藻型地衣 Narrowly lobed foliose chlorolichens (NFL)	高光照生境 High-light habitat
短根条衣 Everniastrum nepalense (Evenep)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	NFL	高光照生境 High-light habitat
卷梢哑铃孢 Heterodermia boryi (Hetbor)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	NFL	高光照生境 High-light habitat
云南袋衣 Hypogymnia yunnanensis (Hypyun)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	NFL	高光照生境 High-light habitat
裂髓树花 Ramalina conduplicans (Ramcon)	绿藻 Green alga	直立枝状 Shrubby fruticose	直立枝状绿藻型地衣 Shrubby fruticose chlorolichens (SFL)	高光照生境 High-light habitat
槽枝衣 Sulcaria sulcata (Sulsul)	绿藻 Green alga	直立枝状 Shrubby fruticose	SFL	高光照生境 High-light habitat
多花松萝 Usnea florida (Usnflo)	绿藻 Green alga	直立枝状 Shrubby fruticose	SFL	高光照生境 High-light habitat
巢松萝 Usnea dasopoga (Usndas)	绿藻 Green alga	悬垂枝状 Pendent fruticose	悬垂枝状绿藻型地衣 Pendent fruticose chlorolichens (PFL)	高光照且干燥生境 High-light and dry habitat
长松萝 Usnea longissima (Usnlon)	绿藻 Green alga	悬垂枝状 Pendent fruticose	PFL	高光照潮湿生境 High-light and humid habitat

物种 Species	共生藻型 Photobiont type	生长型 Growth form	功能群划分 Functional group	主要生境 Main habitat
网肺衣 Lobaria retigera (Lobret)	蓝藻 Cyanobacteria	叶状 Foliose	蓝藻型地衣 Cyanolichen (CYL)	阴湿至高光照湿润生境 Shaded to high-light and humid habitat
猫耳衣 Leptogium menziesii(Lepmen)	蓝藻 Cyanobacteria	叶状 Foliose	CYL	潮湿环境 Humid habitat
黑芽牛皮叶 Sticta fuliginosa(Stiful)	蓝藻 Cyanobacteria	叶状 Foliose	CYL	潮湿高光照生境 Humid and high-light habitat
针芽肺衣 Lobaria isidiophora(Lobisi)	绿藻 Green alga	阔叶型 Broadly lobed foliose	阔叶绿藻型地衣 Broadly lobed foliose chlorolichens (BFL)	中光至高光照生境 Medium to high-light habitat
网大叶梅 Parmotrema reticulatum (Parret)	绿藻 Green alga	阔叶型 Broadly lobed foliose	BFL	中光至高光照、潮湿生境 Medium to high-light, and humid habitat
平滑牛皮叶 Sticta nylanderiana (Stinyl)	绿藻 Green alga	阔叶型 Broadly lobed foliose	BFL	中光至高光照生境 Medium to high-light habitat
黑腹绵腹衣 Anzia hypomelaena (Anzhyp)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	狭叶绿藻型地衣 Narrowly lobed foliose chlorolichens (NFL)	高光照生境 High-light habitat
短根条衣 Everniastrum nepalense (Evenep)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	NFL	高光照生境 High-light habitat
卷梢哑铃孢 Heterodermia boryi (Hetbor)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	NFL	高光照生境 High-light habitat
云南袋衣 Hypogymnia yunnanensis (Hypyun)	绿藻 Green alga	狭叶型 Narrowly lobed foliose	NFL	高光照生境 High-light habitat
裂髓树花 Ramalina conduplicans (Ramcon)	绿藻 Green alga	直立枝状 Shrubby fruticose	直立枝状绿藻型地衣 Shrubby fruticose chlorolichens (SFL)	高光照生境 High-light habitat
槽枝衣 Sulcaria sulcata (Sulsul)	绿藻 Green alga	直立枝状 Shrubby fruticose	SFL	高光照生境 High-light habitat
多花松萝 Usnea florida (Usnflo)	绿藻 Green alga	直立枝状 Shrubby fruticose	SFL	高光照生境 High-light habitat
巢松萝 Usnea dasopoga (Usndas)	绿藻 Green alga	悬垂枝状 Pendent fruticose	悬垂枝状绿藻型地衣 Pendent fruticose chlorolichens (PFL)	高光照且干燥生境 High-light and dry habitat
长松萝 Usnea longissima (Usnlon)	绿藻 Green alga	悬垂枝状 Pendent fruticose	PFL	高光照潮湿生境 High-light and humid habitat

共生藻型 Photobi-ont type	生长型 Growth form	物种 Species	内部含水量 WC_internal (%, Dry mass)	共质体水 Rs (%, Dry mass)	质外体水 Ra (%, Dry mass)	膨压损失点的相对含水量 RWC_TLP(%)	膨压损失点的渗透势Ψ_TLP (MPa)	饱和渗透势 Ψsat (MPa)
蓝藻 Cyanob-acteria			328.66 ± 36.84 ^Ac	322.08 ± 36.79 ^Ac	6.58 ± 1.19 ^Aab	40.96 ± 3.97 ^Abc	-3.44 ± 0.33 ^Aa	-1.29 ± 0.13 ^Aab
	叶状 Foliose	网肺衣 Lobaria retigera	214.86 ± 11.54	208.02 ± 11.14	6.85 ± 2.64	55.34 ± 2.95	-2.84 ± 0.35	-1.55 ± 0.24
		猫耳衣 Leptogium menziesii	497.80 ± 43.93	492.40 ± 43.56	5.40 ± 1.44	22.68 ± 1.49	-3.86 ± 0.53	-0.85 ± 0.14
		黑芽牛皮叶 Sticta fuliginosa	273.31 ± 32.08	265.81 ± 29.86	7.49 ± 2.30	44.86 ± 3.91	-3.63 ± 0.77	-1.46 ± 0.20
绿藻 Green alga			155.28 ± 8.95 ^B	149.71 ± 8.73 ^B	5.57 ± 0.45 ^A	46.93 ± 1.54 ^A	-3.80 ± 0.22 ^A	-1.71 ± 0.11 ^A
	阔叶型 Broadly lobed foliose		137.05 ± 7.67 ^ab	130.05 ± 7.18 ^ab	7.00 ± 0.80 ^a	56.89 ± 2.73 ^a	-3.45 ± 0.30 ^a	-1.89 ± 0.18 ^c
		针芽肺衣 Lobaria isidiophora	133.11 ± 10.40	128.03 ± 9.95	5.08 ± 1.20	65.68 ± 3.14	-3.85 ± 0.37	-2.47 ± 0.24
		网大叶梅 Parmotrema reticulatum	119.18 ± 12.49	112.58 ± 11.77	6.60 ± 0.79	45.66 ± 3.44	-3.41 ± 0.78	-1.44 ± 0.32
		平滑牛皮叶 Sticta nylanderiana	158.87 ± 12.26	149.55 ± 11.44	9.32 ± 1.57	59.34 ± 2.00	-3.08 ± 0.34	-1.75 ± 0.18
	狭叶型 Narrowly lobed foliose		185.42 ± 23.36 ^ab	179.71 ± 22.70 ^ab	5.71 ± 0.93 ^ab	45.75 ± 2.23 ^bc	-3.74 ± 0.43 ^ab	-1.72 ± 0.23 ^abc
		黑腹绵腹衣 Anzia hypomelaena	349.87 ± 25.89	339.44 ± 25.63	10.43 ± 1.08	33.88 ± 1.99	-1.58 ± 0.19	-0.50 ± 0.07
		短根条衣 Everniastrum nepalense	115.29 ± 6.35	111.44 ± 6.40	3.86 ± 0.40	48.52 ± 2.02	-4.74 ± 0.75	-2.28 ± 0.44
		卷梢哑铃孢 Heterodermia boryi	109.69 ± 9.46	107.74 ± 9.72	1.95 ± 0.46	51.66 ± 1.29	-4.98 ± 0.81	-2.52 ± 0.42
		云南袋衣 Hypogymnia yunnanensis	166.81 ± 7.57	160.20 ± 7.77	6.61 ± 2.20	48.94 ± 6.04	-3.64 ± 0.72	-1.56 ± 0.25
	直立枝状 Shrubby fruticose		153.06 ± 10.08 ^a	149.03 ± 9.88 ^a	4.03 ± 0.77 ^b	39.15 ± 2.46 ^c	-4.82 ± 0.45 ^b	-1.85 ± 0.23 ^bc
		裂髓树花 Ramalina conduplicans	148.43 ± 14.35	142.97 ± 13.80	5.46 ± 1.10	48.02 ± 2.01	-5.82 ± 0.89	-2.70 ± 0.42
		槽枝衣 Sulcaria sulcata	128.74 ± 8.78	125.69 ± 8.03	3.05 ± 1.80	40.92 ± 2.38	-3.97 ± 0.54	-1.56 ± 0.16
		多花松萝 Usnea florida	182.00 ± 20.55	178.44 ± 20.20	3.57 ± 0.96	28.52 ± 2.35	-4.68 ± 0.79	-1.29 ± 0.26
	悬垂枝状 Pendent fruticose		125.67 ± 10.85 ^b	120.23 ± 10.56 ^b	5.44 ± 0.78 ^ab	46.03 ± 3.63 ^b	-2.92 ± 0.28 ^a	-1.19 ± 0.06 ^a
		巢松萝 Usnea dasopoga	153.47 ± 10.12	148.05 ± 9.08	5.43 ± 1.20	40.86 ± 3.71	-3.05 ± 0.33	-1.14 ± 0.10
		长松萝 Usnea longissima	97.86 ± 6.33	92.41 ± 5.72	5.45 ± 1.15	51.20 ± 5.65	-2.79 ± 0.48	-1.24 ± 0.08

共生藻型 Photobi-ont type	生长型 Growth form	物种 Species	内部含水量 WC_internal (%, Dry mass)	共质体水 Rs (%, Dry mass)	质外体水 Ra (%, Dry mass)	膨压损失点的相对含水量 RWC_TLP(%)	膨压损失点的渗透势Ψ_TLP (MPa)	饱和渗透势 Ψsat (MPa)
蓝藻 Cyanob-acteria			328.66 ± 36.84 ^Ac	322.08 ± 36.79 ^Ac	6.58 ± 1.19 ^Aab	40.96 ± 3.97 ^Abc	-3.44 ± 0.33 ^Aa	-1.29 ± 0.13 ^Aab
	叶状 Foliose	网肺衣 Lobaria retigera	214.86 ± 11.54	208.02 ± 11.14	6.85 ± 2.64	55.34 ± 2.95	-2.84 ± 0.35	-1.55 ± 0.24
		猫耳衣 Leptogium menziesii	497.80 ± 43.93	492.40 ± 43.56	5.40 ± 1.44	22.68 ± 1.49	-3.86 ± 0.53	-0.85 ± 0.14
		黑芽牛皮叶 Sticta fuliginosa	273.31 ± 32.08	265.81 ± 29.86	7.49 ± 2.30	44.86 ± 3.91	-3.63 ± 0.77	-1.46 ± 0.20
绿藻 Green alga			155.28 ± 8.95 ^B	149.71 ± 8.73 ^B	5.57 ± 0.45 ^A	46.93 ± 1.54 ^A	-3.80 ± 0.22 ^A	-1.71 ± 0.11 ^A
	阔叶型 Broadly lobed foliose		137.05 ± 7.67 ^ab	130.05 ± 7.18 ^ab	7.00 ± 0.80 ^a	56.89 ± 2.73 ^a	-3.45 ± 0.30 ^a	-1.89 ± 0.18 ^c
		针芽肺衣 Lobaria isidiophora	133.11 ± 10.40	128.03 ± 9.95	5.08 ± 1.20	65.68 ± 3.14	-3.85 ± 0.37	-2.47 ± 0.24
		网大叶梅 Parmotrema reticulatum	119.18 ± 12.49	112.58 ± 11.77	6.60 ± 0.79	45.66 ± 3.44	-3.41 ± 0.78	-1.44 ± 0.32
		平滑牛皮叶 Sticta nylanderiana	158.87 ± 12.26	149.55 ± 11.44	9.32 ± 1.57	59.34 ± 2.00	-3.08 ± 0.34	-1.75 ± 0.18
	狭叶型 Narrowly lobed foliose		185.42 ± 23.36 ^ab	179.71 ± 22.70 ^ab	5.71 ± 0.93 ^ab	45.75 ± 2.23 ^bc	-3.74 ± 0.43 ^ab	-1.72 ± 0.23 ^abc
		黑腹绵腹衣 Anzia hypomelaena	349.87 ± 25.89	339.44 ± 25.63	10.43 ± 1.08	33.88 ± 1.99	-1.58 ± 0.19	-0.50 ± 0.07
		短根条衣 Everniastrum nepalense	115.29 ± 6.35	111.44 ± 6.40	3.86 ± 0.40	48.52 ± 2.02	-4.74 ± 0.75	-2.28 ± 0.44
		卷梢哑铃孢 Heterodermia boryi	109.69 ± 9.46	107.74 ± 9.72	1.95 ± 0.46	51.66 ± 1.29	-4.98 ± 0.81	-2.52 ± 0.42
		云南袋衣 Hypogymnia yunnanensis	166.81 ± 7.57	160.20 ± 7.77	6.61 ± 2.20	48.94 ± 6.04	-3.64 ± 0.72	-1.56 ± 0.25
	直立枝状 Shrubby fruticose		153.06 ± 10.08 ^a	149.03 ± 9.88 ^a	4.03 ± 0.77 ^b	39.15 ± 2.46 ^c	-4.82 ± 0.45 ^b	-1.85 ± 0.23 ^bc
		裂髓树花 Ramalina conduplicans	148.43 ± 14.35	142.97 ± 13.80	5.46 ± 1.10	48.02 ± 2.01	-5.82 ± 0.89	-2.70 ± 0.42
		槽枝衣 Sulcaria sulcata	128.74 ± 8.78	125.69 ± 8.03	3.05 ± 1.80	40.92 ± 2.38	-3.97 ± 0.54	-1.56 ± 0.16
		多花松萝 Usnea florida	182.00 ± 20.55	178.44 ± 20.20	3.57 ± 0.96	28.52 ± 2.35	-4.68 ± 0.79	-1.29 ± 0.26
	悬垂枝状 Pendent fruticose		125.67 ± 10.85 ^b	120.23 ± 10.56 ^b	5.44 ± 0.78 ^ab	46.03 ± 3.63 ^b	-2.92 ± 0.28 ^a	-1.19 ± 0.06 ^a
		巢松萝 Usnea dasopoga	153.47 ± 10.12	148.05 ± 9.08	5.43 ± 1.20	40.86 ± 3.71	-3.05 ± 0.33	-1.14 ± 0.10
		长松萝 Usnea longissima	97.86 ± 6.33	92.41 ± 5.72	5.45 ± 1.15	51.20 ± 5.65	-2.79 ± 0.48	-1.24 ± 0.08

水势参数 Water potential parameter	PC1	PC2
共质体水 Rs	0.584	-
质外体水 Ra	0.307	-0.818
质壁分离时相对含水量 RWC_TLP	-0.494	-0.565
饱和渗透势 Ψsat	0.566	-
标准差 Standard deviation	1.451	1.038
方差贡献率 Proportion of variance	52.66%	26.94%
方差累计贡献率 Cumulative proportion	52.66%	79.60%