长白山阔叶红松林样地(CBS)：群落组成与结构

 阔叶红松(Pinus koraiensis)林是中国东北地区的地带性植被,长白山区是阔叶红松林的核心分布区。参照巴拿马Barro Colorado Island (BCI) 50 hm² 热带雨林样地的技术规范,于2004年在长白山自然保护区的阔叶红松林内建立了一块25 hm²的固定样地（简称CBS）,这是目前中国科学院生物多样性委员会中国森林多样性动态研究网络中最北端的一块,也是全球温带地区最大的一块森林样地。2004年夏的第一次调查结果表明,样地内胸径≥1 cm的木本植物有52种,隶属于18科32属。总的独立个体数为38 902,包括分枝的总个体数为59 121。植物组成上属典型的长白山植物区系,同时混有一些亚热带和亚寒带成分。群落优势种明显,个体数最多的前3个种的个体数占到总个体数的60%,前14个种占到95%,而其余38个种只占到5 %。从物种多度、 胸高断面积、平均胸径和重要值来看,群落成层现象显著,具有比较明显的优势种。主要树种的径级结构近似于正态分布或双峰分布,而次林层和林下层树种则表现出倒 “J" 形或 “L"形。红松、紫椴(Tilia amurensis)、蒙古栎(Quercus mongolica)、 水曲柳(Fraxinus mandshurica)、色木槭(Acer mono)和春榆(Ulmus japonica )几个主要树种的空间分布随物种、径级的变化表现出不同的分布格局,其它一些树种的分布格局也表现出一定的空间异质性。

BROAD-LEAVED KOREAN PINE (PINUS KORAIENSIS) MIXED FOREST PLOT IN CHANGBAISHAN (CBS) OF CHINA: COMMUNITY COMPOSITION AND STRUCTURE

Aims To ultimately understand of the mechanisms of species coexistence, the Chinese Academy of Sciences, in collaboration with the Center for Tropical Forest Science (CTFS) of the Smithsonian Tropical Research Institute, has recently initiated an ambitious large-scale, long-term forest dynamics and diversity plots network. Following the protocols of the CTFS forest dynamism plots, the China Network has been designed to establish four 20-25 hm² plots along the latitudinal gradient from North to South China. The Changbaishan plot (the CBS plot), the northern most plot of the China Network, is established for the benefit of understanding temperate forest ecosystem. This paper aims to address the community composition and structure of the CBS plot, serving as baseline information accessible for a wide range of future studies.
Methods Following the field protocol of the 50 hm² plot in Barro Colorado Island in Panama, a 25 hm² broad-leaved Korean pine mixed forest permanent plot of 500 m × 500 m was established in the summer of 2004 in Changbaishan. All free-standing individuals with DBH (diameter at breast height) ≥1 cm were tagged, mapped and identified to species.
Important findings There are 38 902 genotype individuals (59 121 individuals with branch), belonging to 52 species, 32 genera and 18 families. Floristic characteristics of the community belong to Changbaishan plant flora, including some tertiary relic species and subtropical species. Three species comprise 52.5% of all individuals, and 14 species comprise 95.2% of all individuals, while other 38 species comprise fewer than 5% of all individuals. The statistics of species
abundance, basal area, mean DBH, and important value showed that there are obviously dominant species in the community. The size-class structure of main species in the overstory layer showed nearly normal or bimodal distribution, while the species in the midstory and understory layers showed invert “J" distribution, even “L" distribution. Spatial distribution patterns of the main species, Pinus koraiensis, Tilia amurensis, Quercus mongolica, Fraxinus mandshurica, Acer mono and Ulmus japonica, changed differently with size-class and scales. Meanwhile, spatial patterns of some other species also showed spatial heterogeneity.