Nematodes as an Indicator of Biological Crust Development in the Tengger Desert, China

Abstract

Nematode communities were investigated on bare soil, physical soil crusts, algal crusts, and moss crusts in Shapotou in the Tengger Desert, China. The objective of the present study is to examine whether nematode communities develop parallel to the biological crust succession. The abundance of nematodes, the proportion of predators, maturity index, the number of nematode taxa identified, and Shannon index were affected significantly by crust type. Bare soil, physical soil crusts, algal crusts, and moss crusts were also comprised of differing community composition as indicated by PRC analysis. These results indicate that nematode communities develop parallel to crust development during the assisted revegetation of migrating sand dunes. Therefore, nematodes could be an indicator of biological crust development in the Tengger Desert, China.

Keywords:

• algal crust
• moss crust
• nematode community
• physical soil crust

This work was supported by the Chunhui Plan and Program for Changjiang Scholars and Innovative Research Team in University. The authors are very grateful to the faculty of the Shapotou Station of Desert Research, Chinese Academy of Science for their help in our sample collection, especially to Dr. Ni Yongqing and laboratory mates Liu Hetao and Xie Qinjian for their assistance in collecting samples, and to Ms. Lynette Anne Ferguson for editting the manuscript linguistically.

Notes

∗Cited from Li, 2005.

†Cited from Li et al., 2003.

‡Soil depth at 0–15 cm.

^§Cited from Shao and Zhao, 2004, soil depth at 0–0.5 cm.

OSD: mean soil moisture on three sampling dates; ARD: soil moisture one day after rainfall; MD: bare soil sampled on migrating sand dunes; PC: physical soil crust; AC: algal crust; MC: moss crust; ND: not detected.

MD, PC, AC, and MC abbreviated as in Table 1.

MD, PC, AC, and MC abbreviated as in Table 1. N: total nematode individuals per 100 g fresh soil; Ba %: the percentage of bacterivores in total individuals; Fu %: the percentage of fungivores in total individuals; Pl %: the percentage of plant-feeders in total individuals; Pr %: the percentage of predators in total individuals; Om %: the percentage of omnivores in total individuals; MI: maturity index; S: the number of nematode taxa identified in a sample; H′: Shannon index.

Means followed by different letters indicate significant differences (P < 0.05) between crusts using Tukey's multiple range test.

Effects: C = crust type; T = time; C × T = crust type × time.