Abstract
Hong Kong is an extreme example of tropical landscape degradation, with no substantial remnants of the original forest cover and a highly impoverished disperser fauna. Seed availability is a potential limiting factor in vegetation recovery in such landscapes. To assess the quantity and quality of the seed rain of woody taxa, seed traps were placed in the major upland vegetation types: fire-maintained grassland, shrubland, and secondary forest. Within the grassland site, traps were placed under isolated trees, isolated male and female shrubs of Eurya chinensis, and in the open. Seeds were collected every 2 weeks for 2 years. The seed rain was highest under female shrubs in grassland (6455 seeds m−2 year−1), where it was almost entirely confined to their fruiting period. Next highest were isolated trees (890 seeds), followed by male isolated shrubs (611 seeds), shrubland (558 seeds), forest (129 seeds) and open grassland (47 seeds). The number of seed taxa was highest in shrubland (59), followed by isolated trees (42), forest (42), female isolated shrubs (28), male isolated shrubs (15), and open grassland (9). The seed rain differed in species composition between the forest, shrubland, and grassland sites, while the differences within the grassland site were largely in terms of quantity. Birds (particularly bulbuls, Pycnonotus spp.) are known or inferred to be the major dispersal agents for 85% of the seed taxa trapped, 99% of the total number of seeds trapped, and 99.8% of the seeds trapped in the grassland site. Few taxa and \(<1\%\) of the total seeds were dispersed by wind and no seed taxa were definitely dispersed by fruit bats. The results suggest that even in the most degraded landscape the seed rain is adequate for the development of woody vegetation cover, but that human intervention will be needed for the restoration of plant diversity.
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References
Clarke K.R., Warwick R.M. (1994) Change in Marine Communities: An Approach to Statistical Analysis and Interpretation. Primer-E Ltd., Plymouth, UK
Corlett R.T. (1991) Plant succession on degraded land in Singapore. J. Trop. Forest Sci. 4:151–161
Corlett R.T. (1996) Characteristics of vertebrate-dispersed fruits in Hong Kong. J. Trop. Ecol. 12:819–833
Corlett R.T. (2002) Frugivory and seed dispersal in degraded tropical East Asian landscapes. In: Levey D.J., Silva W.R., Galetti M. (eds) Seed Dispersal and Frugivory: Ecology, Evolution and Conservation. CABI Publishing, Wallingford, UK, pp 451–465
Cubina A., Aide T.M. (2001) The effect of distance from forest edge on seed rain and soil seed bank in a tropical pasture. Biotropica 33:260–267
Dudgeon D., Corlett R.T. (2004) The Ecology and Biodiversity of Hong Kong. Joint Publishing, Hong Kong, China
Duncan R.S., Chapman C.A. (1999) Seed dispersal and potential forest succession in abandoned agriculture in Tropical Africa. Ecol. Appl. 9:998–1008
Guevara S., Laborde J., Sanchez-Rios G. (2004) Rain forest regeneration beneath the canopy of fig trees isolated in pastures of Los Tuxtlas, Mexico. Biotropica 36:99–108
Hau C.H. (1997) Tree seed predation on degraded hillsides in Hong Kong. Forest Ecol. Manage. 99:215–221
Hau B.C.H., Corlett R.T. (2003) Factors affecting the early survival and growth of native tree seedlings planted on a degraded hillside grassland in Hong Kong, China. Restor. Ecol. 11:1–6
Holl K.D. (1998) Do bird perching structures elevate seed rain and seedling establishment in abandoned tropical pasture? Restor. Ecol. 6:253–261
Holl K.D. (1999) Factors limiting tropical forest regeneration in abandoned pasture: seed rain, seed germination, microclimate, and soil. Biotropica 31:229–242
Hong Kong Herbarium. (2004) Checklist of Hong Kong Plants 2004. Agriculture, Fisheries and Conservation Department, Hong Kong, China
Hong Kong Observatory. (2004) Summary of Meteorological Observations in Hong Kong 2003. Hong Kong Observatory, Hong Kong, China
Howe H.F., Miriti M.N. (2004) When seed dispersal matters. BioScience 54:651–660
Ingle N.R. (2003) Seed dispersal by wind, birds, and bats between Philippine montane rainforest and successional vegetation. Oecologia 134:251–261
Kwok H.K., Corlett R.T. (1999) Seasonality of a forest bird community in Hong Kong, South China. Ibis 141:70–79
Lee E.W.S., Hau B.C.H., Corlett R.T. (2005) Natural regeneration in exotic tree plantations in Hong Kong, China. Forest Ecol. Manage. 212:358–366
Leven M.R. 2000. Shrubland birds in Hong Kong: diet, seasonality and community structure. Unpublished Ph.D. dissertation, University of Hong Kong, Hong Kong, China
Lucas P.W., Corlett R.T. (1998) Seed dispersal by long-tailed macaques. Am. J. Primatol. 45:29–44
Makana J.-R., Thomas S.C. (2004) Dispersal limits natural recruitment of African mahoganies. Oikos 106:67–72
Medellin R.A., Gaona O. (1999) Seed dispersal by bats and birds in forest and disturbed habitats of Chiapas, Mexico. Biotropica 31:478–485
Page M.J., Newlands L., Eales J. (2002) Effectiveness of three seed-trap designs. Aust. J. Bot. 50:587–594
Phua P.B., Corlett R.T. (1989) Seed dispersal by the Lesser Short–nosed Fruit Bat (Cynopterus brachyotis, Pteropodidae, Megachiroptera). Malayan Nat. J. 42:251–256
Primack R.B., Corlett R.T. (2005) Tropical Rainforests: An Ecological and Biogeographical Comparison. Blackwell Science, Oxford, UK
Toh I., Gillespie M., Lamb D. (1999) The role of isolated trees in facilitating tree seedling recruitment at a degraded sub-tropical rainforest site. Restor. Ecol. 7:288–297
Tucker N.J., Murphy T.M. (1997) The effects of ecological rehabilitation on biodiversity recruitment: some observations from the wet tropics of north Queensland. Forest Ecol. Manage. 99:133–152
Uhl C. (1987) Factors controlling succession following slash-and-burn agriculture in Amazonia. J. Ecol. 75:377–408
Weir J.E.S. 2004. Patterns of seed dispersal by flying frugivores in Hong Kong. Unpublished M.Phil dissertation, University of Hong Kong, Hong Kong, China
Zhuang X., Corlett R.T. (1997) Forest and forest succession in Hong Kong, China. J. Trop. Ecol.14:857–866
Acknowledgements
This study was funded by a Research Grants Council grant to the second author (RGC HKU 7183/01M) and forms part of a larger project on forest recovery in the degraded upland landscape of Hong Kong. We gratefully acknowledge help from Kylie Chung and Laura Wong in the field and laboratory, and access to unpublished observations and data from Jacqui Weir.
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Au, A.Y.Y., Corlett, R.T. & Hau, B.C.H. Seed rain into upland plant communities in Hong Kong, China. Plant Ecol 186, 13–22 (2006). https://doi.org/10.1007/s11258-006-9108-5
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DOI: https://doi.org/10.1007/s11258-006-9108-5