Effects of water level and light intensity on capsule production dynamics of Sphagnum capillifolium

doi:10.17521/cjpe.2015.0048

Abstract

Abstract: Aims

Our objective was to analyze the effect of water levels and light intensities on capsule production dynamics of Sphagnum to lay the foundation for further research on its reproductive phenology.

Methods

Our selected Sphagnum capillifolium in this study. We set up a simulation experiment within a growth chamber and grew moss communities in polystyrene containers. Water levels and light intensities were altered to create different environmental conditions. Gametophores and capsule production were observed and recorded.

Important findings

Seta length, shoot height and capsule cracking rate increased when water level increased. Under high light intensities, capsule diameter and capsule cracking rate were higher. Water level and light intensity had an interactive effect on shoot height increment and capsule diameter. Water level and light intensity had no effect on capsule production rate. Increase in both water level and light intensity led to earlier spore release. Reproductive phenology advance can reduce the abortive risk of spores by avoiding detrimental environment conditions such as drought. After capsules dehisced, reproductive shoots were able to accelerate height growth to avoid shading to lay a foundation for further reproduction in the future.

Key words: Sphagnum, water level, light intensity, phenology

YUAN Min,BU Zhao-Jun,LIU Chao,MA Jin-Ze,WANG Sheng-Zhong. Effects of water level and light intensity on capsule production dynamics of Sphagnum capillifolium[J]. Chin J Plan Ecolo, 2015, 39(5): 501-507.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2015.0048

https://www.plant-ecology.com/EN/Y2015/V39/I5/501

Figures/Tables 7

Fig. 1 Morphological change in Sphagnum capillifolium capsules. The capsule highlighted by the arrow is an example under low water level and weak light conditions. A, On July 21, a newborn spherical capsule is yellow, wrapped by perichaetial leaves and no seta developed. B, On August 2, a seta gradually formed and elongated and the capsule was dark brown. C, On August 6, the seta further extended and the capsule became red brown in color and thick cylindrical in shape. D, On August 8, after operculum falling off, spores released and the capsule became thin cylindrical in shape.

Table 1 Two-way ANOVA for effects of water level and light intensity on height increment and sporophyte morphology

指标 Index	水位 Water level		光强 Light intensity		水位×光强 Water level × light intensity
指标 Index	F	p	F	p	F	p
繁殖株高增长 Height increment of reproductive shoots	16.66	< 0.001^**	0.21	0.651	7.26	0.008^**
营养株高增长 Height increment of vegetative shoots	4.44	0.036^*	1.21	0.273	6.08	0.015^*
蒴柄长度 Seta length	10.32	0.002^**	0.00	0.966	0.64	0.426
孢蒴直径 Capsule diameter	0.04	0.838	14.73	0.000^**	13.77	< 0.001^**

Fig. 2 Effect of water level and light intensity on shoot height increment (A) and sporophyte morphology (B) (mean ± SE). A, ambient light; H, high water level; L, low water level; W, weak light.

Table 2 Repetitive measurement and analysis of variance (ANOVA) for effects of water level and light intensity on capsule production dynamics

指标 Index	水位 Water level		光强 Light intensity		水位×光强 Water level × light intensity
	F	p	F	p	F	p
孢蒴增长率 Capsule growth rate	0.74	0.403	0.62	0.443	0.23	0.636
孢蒴开裂率 Capsule cracking rate	5.80	0.037^*	5.39	0.033*	0.24	0.554
孢蒴遮蔽率 Rate of capsules being shaded	11.82	0.003^**	0.07	0.792	2.67	0.122

Table 3 Time needed for each stage of capsule production under different water level and light intensity (mean ± SD)

条件 Condition	孢蒴形成→孢蒴成熟 Capsule formation→ Capsule maturation	孢蒴成熟→蒴柄长成 Capsule maturation→ Seta maturation	蒴柄长成→孢蒴开裂 Seta maturation→ Capsule dehiscing
高水位 High water level	11.0 ± 1.2	2.7 ± 1.2	2.3 ± 1.4
低水位 Low water level	12.1 ± 2.4	3.8 ± 1.9	4.1 ± 2.4
一般光强 Ambient light	10.4 ± 1.5	2.3 ± 1.4	2.5 ± 1.3
弱光强 Weak light	12.7 ± 1.7	3.4 ± 1.9	3.9 ± 2.5

Fig. 3 Effect of water level and light intensity on capsule cracking rate and shaded rate (mean ± SE). A, ambient light; H, high water level; L, low water level; W, weak light.

Fig. 4 Linear correlation between the number of new capsules and that of initial ones.

References 32

1	Bao WM, Cao JG (2001). Spore germination and sexual reproduction in Sphagnum.Bulletin of Biology, 36(1), 8-9(in Chinese).
	[包文美, 曹建国 (2001). 泥炭藓及其孢子萌发和有性生殖. 生物学通报, 36(1), 8-9.]
2	Bragazza L (2008). A climatic threshold triggers the die-off of peat mosses during an extreme heat wave.Global Change Biology, 14, 2688-2695.
3	Bragazza L, Parisod J, Buttler A, Bardgett RD (2013). Biogeochemical plant-soil microbe feedback in response to climate warming in peatlands.Nature Climate Change, 3, 273-277.
4	Bu ZJ, Rydin H, Chen X (2011). Direct and interaction- mediated effects of environmental changes on peatland bryophytes.Oecologia, 166, 555-563.
5	Bubier JL, Moore TR, Bledzki LA (2007). Effects of nutrient addition on vegetation and carbon cycling in an ombrotrophic bog.Global Change Biology, 13, 1168-1186.
6	Clymo RS (1998). Sphagnum, the peatland carbon economy, and climate change. In: Bates JW, Ashton NW, Duckett JG eds. Bryology for the Twenty-first Century. Maney Publishing and the British Bryological Society, Leeds, UK. 361-368.
7	Cronberg N (1993). Reproductive biology of Sphagnum.Lindbergia, 17, 69-82.
8	Crum H (1972). The geographic origins of the mosses of North America’s eastern deciduous forest.Journal of the Hattori Botanical Laboratory, 35, 269-298.
9	Ehrlén J, Bisang I, Hedenäs L (2000). Costs of sporophyte production in the moss, Dicranum polysetum.Plant Ecology, 149, 207-217.
10	Gao Q, Cao T, Fu X (2000). Types of spore dispersal of mosses in relation to evolution system.Acta Botanica Yunnanica, 22, 268-276(in Chinese with English abstract).
	[高谦, 曹同, 付星 (2000). 藓类植物传孢类型及其系统演化关系. 云南植物研究, 22, 268-276. ]
11	Glime JM (. Cited: Feb. 2015.
12	Gravobik SI (1986). Influence of some ecological factors on the spore productivity of Sphagnum mosses. Botanicheskii Zhurnal (in Russian), 71, 1652-1657.
13	Ingold CT (1965). Spore Liberation. Clarendon Press, Oxford.
14	Johansson V, Lönnell N, Sundberg S, Hylander K (2014). Release thresholds for moss spores: The importance of turbulence and sporophyte length.Journal of Ecology, 102, 721-729.
15	Jones EW (1986). Bryophytes in chawley brick pit, Oxford, 1948-1985.Journal of Bryology, 14, 347-358.
16	Longton RE (1997). Reproductive biology and life-history strategies.Advances of Bryology, 6, 65-101.
17	Moore TR, Roulet NT, Waddington JM (1998). Uncertainty in predicting the effect of climatic change on the carbon cycling of Candian peatlands.Climatic Change, 40, 229-245.
18	Nawaschin S (1897). Über die Sporenausschleuderung bei den Torfmoosen.Flora, 48, 151-159.
19	Rochefort L (2000). Sphagnum―A keystone genus in habitat restoration.The Bryologist, 103, 503-508.
20	Rudolph H, Kirchhoff M, Gliesmann S (1988). Sphagnum culture techniques. In: Glime JM ed. Methods in Bryology. Hattori Botanical Laboratory, Nichinan. 25-34.
21	Rydin H, Clymo RS (1989). Transport of carbon and phosphorus compounds about Sphagnum.Proceedings of the Royal Society of London Series B: Biological Sciences, 237, 63-84.
22	Söderström L, Herben T (1997). Dynamics of bryophyte metapopulations.Advances of Bryology, 6, 205-240.
23	Soro A, Sundberg S, Rydin H (1999). Species diversity, niche metrics and species associations in harvested and undisturbed bogs.Journal of Vegetation Science, 10, 549-560.
24	Stark LR, Mishler BD, McLetchie DN (2000). The cost of realized sexual reproduction: Assessing patterns of reproductive allocation and sporophyte abortion in a desert moss.American Journal of Botany, 87, 1599-1608.
25	Sundberg S (2000). The ecological significance of sexual reproduction in peat mosses (Sphagnum).Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 581, 1-37.
26	Sundberg S (2002). Sporophyte production and spore dispersal phenology in Sphagnum: The importance of summer moisture and patch characteristics.Canadian Journal of Botany, 80, 543-556.
27	Sundberg S (2005). Larger capsules enhance short-range spore dispersal in Sphagnum, but what happens further away?Oikos, 108, 115-124.
28	Sundberg S (2010). Size matters for violent discharge height and settling speed of Sphagnum spores: Important attributes for dispersal potential.Annals of Botany, 105, 291-300.
29	Sundberg S (2013). Spore rain in relation to regional sources and beyond.Ecography, 36, 364-373.
30	Sundberg S, Rydin H (1998). Spore number in Sphagnum and its dependence on spore and capsule size.Journal of Bryology, 20, 1-16.
31	Sundberg S, Rydin H (2000). Experimental evidence for a persistent spore bank in Sphagnum.New Phytologist, 148, 105-116.
32	Whitaker DL, Edwards J (2010). Sphagnum moss disperses spores with vortex rings.Science, 329, 406.

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