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New Progress on Seed Supply and Regeneration Potential for Plantations in Southern China Made

Date: Apr 20, 2010
Supported by the Natural Science Foundation of China and supervised by Prof. REN Hai, two postgraduates of South China Botanical Garden, WANG Jun and LI Danyan have studied the seed supply and the regeneration potential for plantations and shrubland in southern China and obtained new discovery.
Currently in southern China, large areas of former degraded lands have benn covered by plantations, However, such plantations remain in the pioneer stages, and succession to more natural communities is inhibited. Assessing the characteristics of seed supply will be vital to better understand the dynamics of forest regeneration.
In this study, the aboveground vegetation, the seed rain, the seed bank, and natural seedling emergence in four typical 24-yr-old plantations (eucalyptus, mixed-native, mixed-legume, and mixed-conifer) and a naturally successioned shrubland in southern China were surveyed. The researchers found that the seed rain and the seed bank were dominated by shrubs and herbs but indigenous tree species were rare. The seed rain consisted mostly of seeds derived from the local plant community. Seed abundance was greater in the seed bank than in the seed rain, and species richness was greater in the seed bank and in the corresponding plant community than in the seed rain. Species composition similarity between the seed rain, the seed bank, and the aboveground vegetation was low, because the seed rain contained much fewer species, and the seed bank and aboveground vegetation contained many different species, respectively.
These findings indicate that both the seed rain and the seed bank play important roles in providing seeds for plant recruitment in the understory, but the seed bank contributes more than the current seed rain to the diversity of recruited plants. The current plant community has little impact on the qualitative composition of the seed rain and seed bank. Based on these data, it appears that succession to the desired zonal, mature forest community is unlikely to result from seeds in the seed rain or seed bank. Lack of seed availability of desired zonal mature forest species is the main bottleneck currently limiting succession in the plantations. Reintroduction of late-successional species could facilitate the desired succession.
The result of this study is currently online in Forest Ecology and Management.

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