沱江流域亚热带次生植被生物量及其模型

BIOMASS AND BIOMASS MODELS OF SECONDARY SUBTROPICAL VEGETATION IN TUOJIANG RIVER VALLEY

本文采用标准地法、标准木及回归分析法（乔木）和样方收获法（灌木和草本）研究了沱江流域清水河支流次生植被生物量及其分配规律，并从生物量协调性角度探讨了主要树种的适宜性。１．应用１１种回归模型研究沱江流域主要次生植被类型优势种生物量与胸径或材积因子的关系，表明以Ｙ＝ａＸｂ模型相关性最好，应用性强，其相关系数范围在０．９４６～０．９９９。２．不同群落类型地上部分生物量的大小排序为柏木、栓皮栎林＞木岂木、柏木林＞柏木林＞铁仔、黄荆灌丛＞马桑灌草丛，其地上部分生物量分别为９５．７２１、７７．５４６、３８．７１９、１１．９６９和４．０７３ｔｈｍ－２。另外两类墨西哥柏林的地上部分生物量分别为２１．０６５和１６．８１０ｔｈｍ－２。３．乡土树种和墨西哥柏根桩及粗根的生物量占各自总根量的比例分别为８０．４２％和６２．０９％，其地下部分生物量占各自总生物量的比例分别为２３．８９％和７．４４％，占各自地上部分生物量的比例分别为１７．６７％和６．９％，表明引入沱江流域的墨西哥柏地上部分和地下部分生物量的不协调，存在潜在的易倒趋势。４．对比分析和评价了主要次生植被类型及树种生物量分配及垂直结构，生产潜力和防护效能，提出较高演替阶段的群?

The biomass and biomass allocation principles of the secondary vegetation in the Qingshuihe tributary of Tuojiang river valley were investigated using field investigation,sample tree and regression analysis (for arbors) and plot harvest (for shrubbery and herbs). The adaptivity of main species was investigated from the viewpoint of biomass distributive coordination in this paper.1. In order to approach the relationships between biomass of main secondary vegetation type and DBH or volume,11 models of regression analysis were set up.Among the models,Y=aXb was the best with coefficients ranging from 0946 to 0999.2. The sequence in which aboveground biomasses varied among different community types was as follows:Quercus variabilis+Cupressus funebris-Rhamnus leptophylla+Elaeagnus pungens-Imperata cylindrica var.major community(95721t·hm-2)>Cupressus funebris+Alnus cremastogyne-Vitex negundo+Coriaria nepalensis-Imperata cylindrica var.major+Plantago asiatica community(546t·hm-2)>Cupressus funebris-Plantago asiatica+Ficus tikoua+Heteropogon contortus community(38719t·hm-2)>Vitex negundo+Coriaria nepalensis+Elaeagnus pungens+Myrsine africanaImperata cylindrica var.major community(11969t·hm-2)>(Coriaria nepalensis)Imperata cylindrica var.major+Heteropogon contortus+Plantago asiatica community(4073t·hm-2),The aboveground biomass of two types of Cupressus lusianica were 21065t·hm-2 and 16810t·hm-2,respectively.3 Stump and thickroots(>20cm in diameter) contributed to 8042% and 6209% of their own total root biomass,respectively,in indigenous species and Cupressus lusianica. Underground biomasses accounted for 2389% and 744% of total biomass respectively,or for 1767% and 69% of aboveground biomass respectively.This indicates a uncoordination between aboveground biomass and underground biomass of Cupressus lusianica,suggesting potential lodging.4 This paper made a contrasting analysis and evaluation on main secondary vegetation types,the allocations of tree biomass,vertical structure productive potentialities and protective functions,indicating that community types at higher successive stage are the superior model with economic and ecological functions in this region.