July 27th, 2009 Grasslands of Hong Kong
I only took me about 45 minutes from the Boutique Hotel Hong Kong where my company put me up to drive to complete my investigation of the large area of grassland and shrubland. Hong Kongs grass and shrub lands have thrived because of a process of successions to the forest which has slowed down and almost stops human disturbances.
It’s been only until the past few decades that the harvesting of plants, mostly grasses, small shrub and ferns, for domestic fuels to be the major reason which prevented forest succession on uncultivated hillsides of Hong Kong. Due to the end of hillside biomass harvesting, hillside fires have now become an issue. Most likely, there are no natural fires in Hong Kong, but they are all started deliberately, or by human error. The number of hillside fires increase as more people visit the hillsides during dry weather. It’s been estimated that there can be well over 100 fires in one day during the annual Ching Ming and Chung Yeung Festivals.
Grasslands dominate the frequently burned areas because the grass quickly regrows from their base roots after a previous fire. Shrubs will overtake the grasslands, if there are no fires, in ten years. I’ve noted that a Secondary forest, dominated by the Machilus can develop only after 20 to 40 years, so succession of the forest has, apparently, slowed this process down. But, there is no observable discontinuity between shrubland and the secondary forest. In conclusion, the major controlling factors for the rate of succession are most definitely the fires, which aid the grasses and the fire-tolerant shrubs. Natural seed dispersal by birds will bring in new scrub and trees which will aid in the competition between plants. Only the plants that can grow higher to reach light, or the shade tolerant plant will be the ones to survive the fast growing secondary forest.
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