Population structure and regeneration types of Ilex spp. in Tiantong National Forest Park, Zhejiang Province

Key words: 
• forest ecology /
• Ilex species /
• DBH class distribution /
• population structure /
• regeneration types /
• protective measures

Abstract: The Ilex species has been recognized for potential role in landscaping. Most of the research focused on genetic, biological, chemical and propagation characteristics of the species. This study aimed to provide the ways to strengthen conservation measures and utilization for Ilex species based on age and population structure. The four sampling plots （each of 20 m 20 m size） were established in subtropical, evergreen broadleaf forests in Tiantong National Forest Park, Zhejiang Province. All woody species in the plots were identified and measured to quantify population structure and regeneration types. The complete randomized design （CRD） with sub-sampling of Ilex species in each sampling plot were used in this study. The four plots were used as replicates to represent different Ilex species in the study area. Results showed: 1） 61 woody species overall with a forest structure mainly consisting of a tree canopy layer and a shrub layer along with an herb layer. An emergent layer, consisting of Ilex micrococca, Pinus massoniana, and Acer acutum species within each plot, was found only in three plots. 2） The age structure of Ilex species in all studied plots were categorized into four types: （a） the increasing pyramid type--Ilex kengii, （b） the stable type--Ilex rotunda, （c） the mature type--Ilex chinensis, and （d） the decreasing type--Ilex micrococca. 3） Overall Ilex species grew very well, but Ilex micrococca, lacking saplings and sprouts, needed special attention along with Ilex chinensis which had very little regeneration. Thus, suitable artificial breeding and cultivation techniques should be applied for conservation of Ilex species and favorable breeding germplasm with necessary protection measures being utilized.［Ch, 2 fig. 2 tab. 30 ref.］