Regeneration Of Quercus Aliena Var. Acuteserrata Population And Biodiversity Conservation Strategy In Shennongjia Area

Unique geographic location and complex terrain provide Shennongjia area with rich biodiversity and relatively integrated forest ecosystem. With great value in soil and water conservation and ecosystem stability maintenance, Quercus aliena var. acuteserrata is a very important dominant species in this area. Some factors affecting the regeneration of Q. aliena var. acuteserrata were studied and the regional biodiversity conservation strategies were also explored in this dissertation.The results of seed rain pattern of Q. aliena var. acuteserrata forest showed that the density of seed rain varied greatly in different plots, seed yield was obviously affected by spatial location and seed traits (including insect infected, immature and viable), but no visible difference was observed with different distances from the mother tree in the range we studied. However, there was no correlation between the spatial patterns of seed rain and the seedlings distribution in the plots investigated. It was also observed that the time of acronfall was earlier for the insect infected seeds than the viable ones, which could be very useful for energy-saving. The distinct peak of acornfall and defoliation may be very helpful for the establishment of the seedlings. Insect infection was also a limiting factor affecting seed survival and the natural regeneration of Q. aliena var. acuteserrata population. In addition, the cyclic production of large seed crops by Q. aliena var. acuteserrata population was very clear and the seed-bearing periodicity was about 2 yearsThe impacts of rodent activities on seeds dispersal of Quecus aliena var. acuteserrata were studied. There were altogether 8 species of rodents (belonging to 3 Family, 4 Genera) captured using steel removal traps. The results showed that the forage habits of rodents were different in different forest types and periods, the rodents' hunting activities and seeds dispersal distance were also affected by the shrub types.The impacts of light on seedling regeneration of Q. aliena var. acuteserrata were studied and the results showed that there were plenty of seedlings under the forest gapand canopy, but very few saplings in the same sample plots. Influence of the slopes with different directions on population regeneration was also studied, and it showed that the slope direction was one important factor for regeneration. The nursery experiments under sunlight gradient treatments showed that the resource allocation ratio was different under different sunlight treatments and the seedling growth of Q. aliena var. acuteserrata might need a proper proportion of shade environment.The populations of Q. aliena var. acuteserrata and Fagus engleriana are both widely distributed in Shennongjia area. The elevation range of them was similar and some mixed forest was found in some areas. Different light use strategies for the regeneration of two species were observed through studying of their photosynthetic rates and resource allocation. For the population of F. engleriana, it showed some shade-tolerant abilities and the excellent understory regeneration. However, for Q. aliena var. acuteserrata, understory saplings were very few and the regeneration might need larger gap and secondary bare area.Shennongjia National Nature Reserve (SNNR) is one of the nature reserves early established in China and it is also a member of the International Network of Biosphere Reserves by United Nations Educational, Scientific and Cultural Organization. Since SNNR was set up, some effective measures have been taken for biodiversity conversation, but there also have some potential threats to it now. A case study of the overall situation of the farmers living in SNNR was analyzed. The results showed that the conflicts between community economy development and biodiversity conservation were severe. Other problems mainly include landscape fragmentation caused from human activities, weak ecosystems, etc. To cope with all these conflicts, some measures, such as developing featured economies, popularizing effective energy utilization...