王朗自然保护区引种竹笋：幼竹期异速生长规律的研究

本文以王朗1985年大熊猫主食竹类引种试验以来,筛选出的四个适应性最强的种:石棉玉山竹(Yushania lineolata)、青川箭竹(Fargesia rufa)、糙花箭竹(Fargesia scabrida)和冷箭竹(Bashania fangiana)及本地缺苞剪竹(Fargesia denudata)作材料,研究了各竹种当年生笋、一年生幼竹和二年生成竹的秆、枝、叶、箨和单株间以及与竹笋——幼竹期高径(D~2H)生长间的异速生长常数K的变化规律,建立了数学模型,并对竹笋到一年生幼竹的各器官(组分)的K值进行相关性研究,探讨在竹笋——幼竹期K值的变化规律。另外还根据笋秆K_s值与缺苞箭竹比较,确定各竹种竹笋——幼竹期的长短及进入稳定加固期的时间,评价各竹种的适应性能力。结果表明:笋期秆异速生长最显著的是糙花箭竹,顺次为石棉玉山竹、青川箭竹和冷箭竹。一年生幼竹器官异迷生长缺苞箭竹向多枝性发展,青川箭竹枝与秆之间生长近似于线性关系,秆、枝、叶和单株间成均衡性生长,而石棉玉山竹、糙花箭竹和冷箭竹则向少枝大秆型发展。单株生物量累积速度的主要因子是叶的生长,其次是秆、枝。二年生成竹的K值出现明显的变化,各竹种经竹笋——幼竹期进入稳定加固期的时间是不同的,石棉玉山竹和青川箭竹一般为1—2年,糙花箭竹和冷箭竹约为2—3年。竹笋——幼竹期K值因种和不同生长年龄而发生变化。笋期(秆、单株)生长速度与其笋成竹的秆、枝、叶和单株K值成负相关,但是笋期异速生长越快,则竹笋——幼竹期越长,进入稳定加固期较晚。对于可塑性强, 较为敏感的竹笋——幼竹来说,时间经历越长,对环境的生态适应能力将会变大。生产实践中,可用笋期秆异速生长常数K_s的大小来确定各竹种其笋进入幼竹和成年稳定后的适应能力及适应程度。表中的数字模型可用来预测生物量。

STUDIES ON ALLOMETRIC RELATIONSHIPS OF GROWING FROM BAMBOO SHOOTS INTO INFANTILE BAMBOOS IN INTRODUCED BAMBOOS FOR GIANT PANDA AT WANGLANG NATURAL RESERVE

This paper discusses allometric relationships between each component (including stem biomass, branch biomass, leaf biomass and total above-ground biomass) and their D~2H in different ages. Their makings use them with Yushania lineolata, Fargesia tufa, F. seabrida and Bashania fangiana from introduced bamboos of the most adaptation since 1985, and in comparison with F. denudata at Wanglang. The appropriating grade of each species is approached and lots of mathematic models are also proposed. The results show that F. scabrida has the largest stem, followed by Y. lineolata, then F. rufa and B. fangiana, the appropriating grade also follow this order for stage of bamboo shoots in each species. The constant K of allometric relationships between organs of one-year infantile bamboo indicates that F. denudata tends to develop more branches followed by F. rufa similars to a linear relationship in the development between branch and stem, and the accumulation of total above-ground biomass is in proportion to the growths of its branch, leaf and stem. However, Y. lineolata, F. scabrida and B. fangiana tend to develop less branches and larger stems. There are greater variations in growths of each total above-ground organ for individual. The important factor of the accumulating speed of total above-ground biomass depend on the growth of leavies, then branches and stems take second place. The constant K of allometric relationships of 2-years old bamboo varies significantly. The time from bamboo shoots through infantile bamboos get into firm stage differ from each other. Generally, this period in Y. lineolata and F, rufa are about 1 or 2 years, and it takes about 2 or 3 years in F. scabrida and B. fangiana. The constant K of allometric relationships varies in accordance with different ages and bamboo species in the growing stage from bamboo shoots to infantile bamboos. The amount to make a contribution of each organ to total above-ground biomass is presented by the following order: leaf>stem>branch. In addition, the correlation coefficients of constant K of allometric relationships between each organ show negative co-relation between bamboo shoots and old bamboos in this developing processes.