Chen Ya, Yang Wan Qin, Wu Fu Zhong, Yang Fan, Lan Li Ying, Liu Yu Wei, Guo Cai Hong, Tan Bo
Institute of Ecology & Forestry, Sichuan Agricultural University/Sichuan Province Key Laboratory of Forestry Ecological Engineering in Upper Reaches of Yangtze River/Alpine Forest Ecosystem Research Station/Sichuan Province Key Laboratory of Soil and Water Conservation and Desertification Control, Chengdu 611130, China.
Collaborative Innovation Center of Ecological Security in the Upper Reaches of Yangtze River, Chengdu 611130, China.
Ying Yong Sheng Tai Xue Bao. 2017 Oct;28(10):3360-3368. doi: 10.13287/j.1001-9332.201710.037.
In order to understand the diversity of soil nematodes in the subalpine/alpine forests of the eastern Qinghai-Tibet Plateau, soil nematodes in the primary forest, mixed forest and secondary forest of Abies faxoniana were extracted by elutriation and sugar-centrifugation method in July 2015, and the composition and structure characteristics of soil nematode communities were studied in the three forests at different altitudes. A total of 37950 soil nematodes were collected, which belonged to 20 families and 27 genera, and the mean density was 4217 ind·100 g dry soil. Filenchus was the dominant genus in the primary forest, and Filenchus and Pararotylenchus in the mixed forest and secondary forest, respectively. The individual number of each dominant genus was significantly affected by forest type. All nematode individuals were classified into the four trophic groups of bacterivores, fungivores, plant-parasites and omnivore-predators. The fungivores were dominant in the primary and secondary forest and the bacterivores in the mixed forest. The number of soil nematode c-p (colonizer-persister) groups of c-p 1, c-p 2, c-p 3 and c-p 4 accounted for 6.1%, 51.1%, 30.0% and 12.7% of the total nematode abundance, respectively. The maturity index (MI), the total maturity index (∑MI) and the plant parasitic index (PPI) of soil nematodes decreased gradually with the increase of altitude. The nematode channel ratio in the mixed forest was higher than 0.5, but that in the primary forest and secondary forest was below 0.5. The forest type significantly affected the soil nematode maturity index and channel ratio, but the forest type, soil layer and their interaction had no significant effect on the diversity index. There were obvious diffe-rences in the composition, nutrient structure and energy flow channel of soil nematodes in the subalpine/alpine forests of western Sichuan, providing an important reference for understanding the function of soil nematodes in soil processes of this region.
为了解青藏高原东部亚高山/高山森林土壤线虫的多样性，于2015年7月采用淘洗-蔗糖离心法提取了岷江冷杉原始林、混交林和次生林中的土壤线虫，并研究了不同海拔高度这三种森林土壤线虫群落的组成和结构特征。共采集到37950条土壤线虫，分属20科27属，平均密度为4217条·100 g干土。丝尾垫刃属是原始林中的优势属，混交林和次生林中的优势属分别是丝尾垫刃属和拟盘旋属。各优势属的个体数量受森林类型影响显著。所有线虫个体被划分为食细菌类、食真菌类、植物寄生类和杂食-捕食类四个营养类群。食真菌类在原始林和次生林中占优势，食细菌类在混交林中占优势。土壤线虫c-p（定殖者-持久者）类群中c-p 1、c-p 2、c-p 3和c-p 4的数量分别占线虫总丰度的6.1%、51.1%、30.0%和12.7%。土壤线虫的成熟度指数（MI）、总成熟度指数（∑MI）和植物寄生指数（PPI）随海拔升高逐渐降低。混交林中线虫通道比高于0.5，而原始林和次生林中低于0.5。森林类型显著影响土壤线虫成熟度指数和通道比，但森林类型、土层及其交互作用对多样性指数无显著影响。川西亚高山/高山森林土壤线虫在组成、营养结构和能量流动通道方面存在明显差异，为了解该地区土壤过程中土壤线虫的功能提供了重要参考。
