濒危树种望天树大量结实后幼苗的生长和存活

doi:10.3773/j.issn.1005-264x.2008.01.006

摘要/Abstract

摘要：

在云南西双版纳州勐腊自然保护区补蚌村的灰阴河望天树(Shorea wantianshuea)林,选择群落结构均一的100 m×200 m区域,设置3条垂直于沟谷并沿谷底到坡顶纵向延伸的20 m×100 m样带 (间隔50 m),在每一样带内每隔20 m设置谷底、低坡、中坡、次坡顶和坡顶5个均匀分布的观测样地,每一样地内设置两个3 m×3 m的小样方。从2004年12月初到2005年9月底每隔2~3个月重复记录幼苗株高、基径和叶片数,统计幼苗死亡数和被动物捕食数,计算幼苗死亡率、动物捕食率和存活率;同时测定各样地土壤含水量。实验结束收获全部现存幼苗,测定和计算幼苗单株叶面积、比叶面积、总生物量和根冠比等生长参数。结果表明:在干旱季节,从谷底到坡顶,各样地土壤含水量依次降低,而幼苗死亡率则依次增大,这种趋势一直持续到实验结束,此时幼苗在谷底、低坡、中坡、次坡顶和坡顶的死亡率分别为55.0%、54.3%、39.4%、35.9%和26.5%。动物捕食导致望天树幼苗的大量损失,但各样地间差异不显著,幼苗的“丢失”也可能是动物捕食的结果。水分胁迫对幼苗生长的影响在干旱季节更为明显,实验结束时幼苗株高在谷底和低坡较大,而在坡顶和次坡顶较小,其它生长参数也都表现出类似的特点,但在实验结束时这些差异并不显著。该文就各种环境因素对望天树幼苗生长与存活的影响进行了讨论。研究的结果可为探寻望天树的致危原因、有效地保护这一珍稀濒危树种和退化次生林的恢复等提供幼苗生态学方面的理论依据。

关键词: 望天树, 幼苗, 生长与存活, 大量结实, 西双版纳季节雨林

Abstract:

Aims Shorea wantianshuea is an endangered tree species of Dipterocarpaceae in Xishuangbanna seasonal rain forest, and is listed in the Plant Red Book under Grade Ⅰ in China. This species regenerates exclusively from seeds. Our objective was to determine the fate of seedlings (including their growth and survival) following a mast fruiting event. Results will be useful in restoring this species and degraded natural forests dominated by it.
Methods In early December 2004, after mast fruiting of S. wantianshuea, we established three parallel 20 m×100 m transects spaced 50 m apart within an area of 100 m×200 m spanning from valley bottom to ridge top. Each transect was stratified into five contiguous plots of 20 m and near the center of each plot two 3 m×3 m quadrats were established. We labeled all newly established S. wantianshuea seedlings in each quadrat, recorded seedling height, basal stem diameter and number of leaves every 2-3 months over a 10-month period and calculated death rate, herbivory rate and survival rate of the seedlings. At the end of the survey, we destructively sampled seedlings and determined leaf areas, total dry weight, root-shoot ratio and specific leaf area.
Important findings Many S. wantianshuea seedlings established after the mast-fruiting event did not recruit into its natural population because of high mortality rate and herbivory rate caused by seasonal drought stress, small mammals and other predators. The density of seedlings was as high as 2.76 plants·m^-2 in December 2004 (first census), but was less than 0.26 plants·m^-2 in September 2005 when the study ended. Seedling mortality rate was high during the dry season, particularly after the first two months. The final seedling mortality rate on ridge-top and lower-ridge sites, 55% and 54%, respectively, were higher than those on other sites, with a gradually increase from valley bottom to ridge top. Herbivory rate in the first census was low and in 8 of 15 sites no seedlings were gnawed or pulled. At the end of the study, mean seedling height was 17.9, 19.7, 18.4, 13.0 and 12.1 cm in valley-bottom, lower-slope, medium-slope, lower-ridge and ridge-top sites, respectively; however, no significant differences were observed in seedling height and other growth parameters.

Key words: Shorea wantianshuea, seedling, growth and survival, mast-fruiting event, Xishuangbanna seasonal rain forest

闫兴富, 曹敏. 濒危树种望天树大量结实后幼苗的生长和存活. 植物生态学报, 2008, 32(1): 55-64. DOI: 10.3773/j.issn.1005-264x.2008.01.006

YAN Xing-Fu, CAO Min. SEEDLING GROWTH AND SURVIVAL OF THE ENDANGERED TREE SPECIES SHOREA WANTIANSHUEA AFTER A MAST-FRUITING EVENT. Chinese Journal of Plant Ecology, 2008, 32(1): 55-64. DOI: 10.3773/j.issn.1005-264x.2008.01.006

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https://www.plant-ecology.com/CN/Y2008/V32/I1/55

图/表 4

参考文献 44

[1]	Aranda I, Castro L, Pardos M, Gil L, Pardos JA (2005). Effects of the interaction between drought and shade on water relations, gas exchange and morphological traits in cork oak (Quercus suber L.) seedlings. Forest Ecology and Management, 210, 117-129.
[2]	Ashton PMS (1992). Some measurements of microclimate within a Sri Lanka tropical rainforest. Agricultural and Forest Meteorology, 59, 217-235.
[3]	Ashton PMS, Gunatilieke CVS, Gunatilieke IAUN (1995). Seedling survival and growth of four Shorea species in a Sri Lanka rainforest. Journal of Tropical Ecology, 11, 263-279.
[4]	Ashton PS, Givinish TJ, Appanah S (1988). Staggered flowering in the Dipterocarpaceae: new insights into the induction and evolution of mast fruiting in the seasonal tropics. The American Naturalist, 132, 44-66.
[5]	Bebber D, Brown N, Speight M (2002). Drought and root herbivory in understorey Parashorea (Kurz) seedlings (Dipterocarpaceae) in Borneo. Journal of Tropical Ecology, 18, 795-804.
[6]	Brown N, Press M, Bebber D (1999). Growth and survivorship of dipterocarp seedlings: differences in shade persistence create a special case of dispersal limitation. Philosophical Transactions of the Royal Society of London Series B, Biological Sciences, 354, 1847-1855.
[7]	Burgess PF (1972). Studies on the regeneration of the hill forests of the Malay Peninsula — the phenology of dipterocarps. Malaysian Forester, 35, 103-123.
[8]	Bücking H, Heyser W (2001). Microautoratio graphic localization of phosphate and carbohydrates in mycorrhizal roots of Populus tremula×Populus alba and implications for transfer processed in ectomycorrhizal associations. Tree Physiology, 21, 101-107.
[9]	Cao M, Zhang JH (1997). Tree species diversity of tropical forest vegetation in Xishuangbanna, SW China. Biodiversity and Conservation, 6, 995-1006.
[10]	Connell JH, Lowman MD (1989). Low-diversity tropical rainforests: some possible mechanisms for their existence. The American Naturalist, 134, 88-119.
[11]	Fu LG (傅立国) (1992). The Red Data Book of Chinese Plants-Rare and Endangered Plants (Volume I) (中国植物红皮书—稀有濒危植物(第1册)). Science Press, Beijing. (in Chinese)
[12]	Gibbons JM, Newbery DM (2003). Drought avoidance and the effect of local topography on trees in the understorey of Bornean lowland rain forest. Plant Ecology, 164, 1-18.
[13]	Grime JP (1965). Shade tolerance in flowering plants. Nature, 208, 161-163.
[14]	Hibbs DE, Chan SS, Castellano M, Niu C (1995). Response of red alder seedlings to CO₂ enrichment and water stress. New Phytologist, 129, 569-577.
[15]	Holl KD, Quiros-Nietzen E (1999). The effect of rabbit herbivory on reforestation of abandoned pasture in southern Costa Rica. Biological Conservation, 87, 391-395.
[16]	Howlett BE, Davidson DW (2001). Herbivory on planted dipterocarp seedlings in secondary logged forests and primary forests of Sabah, Malaysia. Journal of Tropical Ecology, 17, 285-302.
[17]	Janzen DH (1970). Herbivores and the number of tree species in tropical forest. The American Naturalist, 104, 501-528.
[18]	Lee LS, Alexander IJ (1996). The dynamics of ectomycorrhizal infection of Shorea leprosula seedlings in Malaysian rain forests. New Phytologist, 132, 297-305.
[19]	Mark P, Ashton S, Gunatilleke GVS, Gunatilleke IAUN (1995). Seedling survival and growth of four Shorea species in a Sri Lankan rainforest. Journal of Tropical Ecology, 11, 263-279.
[20]	McLaren KP, McDonad MA (2003). The effects of moisture and shade on seed germination and seedling survival in a tropical dry forest in Jamaica. Forest Ecology and Management, 183, 61-75.
[21]	Mitchell PL, Woodward FI (1988). Responses of three woodland herbs to reduced photosynthetically active radiation and low red to far-red ratio in shade. Journal of Ecology, 76, 807-825.
[22]	Moles AT, Westoby M (2004). What do seedlings die from and what are the implications for evolution of seed size? Oikos, 106, 193-199.
[23]	Molofsky J, Fisher BL (1993). Habitat and predation effects on seedling survival and growth in shade-tolerant tropical trees. Ecology, 24, 261-265.
[24]	Muthukumar T, Sha LQ, Yang XD, Cao M, Tang JW, Zheng Z (2003). Mycorrhiza of plants in different vegetation types in tropical ecosystems of Xishuangbanna, Southwest China. Mycorrhiza, 13, 289-297. URL PMID
[25]	Newbery DM, Campbell EJF, Proctor J, Still MJ (1996). Primary lowland dipterocarp forest at Danum Valley, Sabah, Malaysia, Species composition and patterns in the understorey. Vegetatio, 122, 193-220.
[26]	Osunkoya OO, Ash JE, Hopkins MS, Graham AW (1992). Factors affecting survival of tree seedlings in North Queensland rainforests. Oecologia, 24, 569-578.
[27]	Poorter L, Hayashida-Oliver Y (2000). Effects of seasonal drought on gap and understorey seedlings in Bolivian moist forest. Journal of Tropical Ecology, 16, 481-498.
[28]	Reader RJ, Jalili A, Grime JP, Spencer RE, Matthews N (1993). A comparative study of plasticity in seedling rooting depth in drying soil. Journal of Tropical Ecology, 81, 323-336.
[29]	Simard SW, Perry DA, Jones MD, Myrold DD, Durall DM, Molina R (1997). Net transfer of carbon between ectomycorrhizal tree species in the field. Nature, 388, 579-582.
[30]	Shi ZY (石兆勇), Chen YL (陈应龙), Liu RJ (刘润进) (2003a). Arbuscular mycorrhizal fungi of dipterocarpaceae in Xishuangbanna, Southern Yunnan. Mycosystema (菌物系统), 22, 402-409. (in Chinese with English abstract)
[31]	Shi ZY (石兆勇), Chen YL (陈应龙), Liu RJ (刘润进), Wang WH (王维华) (2003b). Preliminary research on arbuscular mycorrhizal fungi of Dipterocarpaceae in Xishuangbanna, Southern Yunnan. Acta Phytoecologica Sinica (植物生态学报), 27, 360-365. (in Chinese with English abstract)
[32]	Smith T, Huston M (1989). A theory of the spatial and temporal dynamics of plant communities. Vegetatio, 83, 49-69.
[33]	Tennakoon MMD, Gunatilleke IAUN, Hafeel KM, Seneviratne CVS, Ashton PMS (2005). Ectomycorrhizal colonization and seedling growth of Shorea (Dipterocarpaceae) species in simulated shade environments of a Sri Lankan rain forest. Forest Ecology and Management, 208, 399-405.
[34]	Turner IM (1990a). The seedling survivorship and growth of three Shorea species in a Malaysian tropical rain forest. Journal of Tropical Ecology, 6, 469-478.
[35]	Turner IM (1990b). Tree seedling growth and survival in a Malaysian rain forest. Biotropica, 22, 146-154.
[36]	Turner IM, Brown ND, Newton AC (1993). The effect of fertilizer application on dipterocarp seedling growth and mycorrhizal infection. Forest Ecology and Management, 57, 329-337.
[37]	Veenendaal EM, Swaine MD, Agyeman VK, Blay D, Abebrese IK, Mulins CE (1996). Differences in plant and soil-water relations in and around a forest gap in West Africa during the dry season may influence seedlings establishment and survival. Journal of Ecology, 84, 83-90.
[38]	Wright SJ (1991). Seasonal drought and the phenology of understory shrubs in a tropical moist forest. Ecology, 72, 1643-1657. DOI URL
[39]	Yan XF (闫兴富), Cao M (曹敏) (2006). Influence of light and temperature on the germination of Shorea wantianshuea (Dipterocarpaceae) seeds. Chinese Bulletin of Botany (植物学通报), 23, 642-650. (in Chinese with English abstract)
[40]	Yin SH (殷寿华), Shuai JG (帅建国) (1990). Study on fruiting behavior, seedling establishment and population age classes of Parashorea chinensis. Acta Botanica Yunnanica (云南植物研究), 12, 415-420. (in Chinese with English abstract)
[41]	Zhang JH, Cao M (1995). Tropical forest vegetation of Xishuangbanna, SW China and its secondary changes, with special reference to some problems in local nature conservation. Biological Conservation, 73, 229-238. DOI URL
[42]	Zhu H (1997). Ecological and biogeographical studies on the tropical rain forest of south Yunnan, SW China, with a special reference to its relation with rain forests of tropical Asia. Journal of Biogeography, 24, 647-662. DOI URL
[43]	Zhu H (朱华) (1992). Studies on the community ecology of Shorea chinensis forest in Xishuangbanna. Acta Botanica Yunnanica (云南植物研究), 14, 237-258. (in Chinese with English abstract)
[44]	Zhu H (朱华) (1993). A comparative study of phytosociology between Shorea chinensis forest of Xishuangbanna and other closer forest types. Acta Botanica Yunnanica (云南植物研究), 15, 34-46. (in Chinese with English abstract)

生长环境 Growth environment	干旱死亡 Mortality (%)				动物捕食 Herbivory (%)				丢失 Missing (%)				存活Survival (%)
生长环境 Growth environment	2	4	6	9	2	4	6	9	2	4	6	9	2	4	6	9
坡顶 RT	33.10	55.02	55.02	55.02	1.67	6.52	11.40	23.06	0.00	6.70	10.22	13.74	65.24	31.77	23.37	8.18
	±15.36	±10.00	±10.00	±10.00	±2.89	±3.03	±7.2	±10.55	0.00	±5.8	±8.86	±8.18	±18.13	±12.56	±18.89	±8.91
次坡顶 LR	44.62	51.24	54.27	54.27	3.33	7.14	11.69	20.81	0.00	13.30	17.70	23.52	52.05	28.31	16.34	2.50
	±20.07	±21.95	±17.87	±17.87	±5.77	±3.72	±7.6	±10.18	0.00	±2.96	±7.41	±5.75	±15.05	±15.5	±3.13	±2.31
中坡 MS	34.23	39.45	39.45	39.45	1.20	3.91	6.37	17.86	0.00	9.53	15.84	22.94	64.47	46.75	38.34	19.75
	±17.1	±19.14	±19.14	±19.14	±1.06	±2.36	±0.96	±3.77	0.00	±7.88	±9.9	±11.49	±17.93	±15.9	±14.08	±11.88
低坡 LS	29.30	34.23	35.46	35.88	0.91	6.00	11.85	23.41	0.00	13.38	17.61	28.32	69.79	46.39	34.59	12.39
	±7.27	±7.73	±4.24	±4.79	±1.57	±5.63	±8.41	±11.24	0.00	±2.01	±0.66	±8.74	±7.41	±4.33	±7.63	±3.87
谷底 VB	20.59	25.85	26.49	26.49	4.91	7.37	21.21	29.89	0.00	23.95	24.94	26.78	74.49	44.63	27.36	16.84
	±3.1	±8.57	±10.34	±10.34	±4.36	±2.62	±8.6	±1.39	0.00	±9.08	±4.3	±4.53	±2.49	±6.86	±3.54	±6.86

生长环境 Growth environment	干旱死亡 Mortality (%)				动物捕食 Herbivory (%)				丢失 Missing (%)				存活Survival (%)
生长环境 Growth environment	2	4	6	9	2	4	6	9	2	4	6	9	2	4	6	9
坡顶 RT	33.10	55.02	55.02	55.02	1.67	6.52	11.40	23.06	0.00	6.70	10.22	13.74	65.24	31.77	23.37	8.18
	±15.36	±10.00	±10.00	±10.00	±2.89	±3.03	±7.2	±10.55	0.00	±5.8	±8.86	±8.18	±18.13	±12.56	±18.89	±8.91
次坡顶 LR	44.62	51.24	54.27	54.27	3.33	7.14	11.69	20.81	0.00	13.30	17.70	23.52	52.05	28.31	16.34	2.50
	±20.07	±21.95	±17.87	±17.87	±5.77	±3.72	±7.6	±10.18	0.00	±2.96	±7.41	±5.75	±15.05	±15.5	±3.13	±2.31
中坡 MS	34.23	39.45	39.45	39.45	1.20	3.91	6.37	17.86	0.00	9.53	15.84	22.94	64.47	46.75	38.34	19.75
	±17.1	±19.14	±19.14	±19.14	±1.06	±2.36	±0.96	±3.77	0.00	±7.88	±9.9	±11.49	±17.93	±15.9	±14.08	±11.88
低坡 LS	29.30	34.23	35.46	35.88	0.91	6.00	11.85	23.41	0.00	13.38	17.61	28.32	69.79	46.39	34.59	12.39
	±7.27	±7.73	±4.24	±4.79	±1.57	±5.63	±8.41	±11.24	0.00	±2.01	±0.66	±8.74	±7.41	±4.33	±7.63	±3.87
谷底 VB	20.59	25.85	26.49	26.49	4.91	7.37	21.21	29.89	0.00	23.95	24.94	26.78	74.49	44.63	27.36	16.84
	±3.1	±8.57	±10.34	±10.34	±4.36	±2.62	±8.6	±1.39	0.00	±9.08	±4.3	±4.53	±2.49	±6.86	±3.54	±6.86