In consequence of the large scale and long term studies on soil zoology in China, a large amount of fundamental data and materials were accumulated. The monograph "Subtropical Soil Animals of China" was coming out in 1992, and in succession a series of relevant articles were also published. These results, however, have push forward further scientific researches on soil zoology and popularized the relevant knowledge in our country. And from 1993, the second nationwide large program "Study of soil animals in different climatic zones of China" has been started, which covering the survey in both Palaearctic and Oriental zoogeographical Realms. There are 7 collecting stations designated in temperate, subtropical and tropical climatic zones of China; and quantitative soil samples are collected monthly from the stations synchronously, in order to obtain a general picture of the present status of soil biota in China.
People gradually recognize and comprehend the soil animal plays an important role, such as improving the soil, promoting the natural material cycling and increasing the grain yield, monitoring the environment contamination and the global air pollution. Therefore, studies on soil zoology have a direct relationship to national economy and people's livelihood. Especially with regard to the present severe air pollution and the soil deterioration have resulted in the reduction of the soil fertility, intensified the lose of biodiversity and decreased the potential of the grain yield, which have brought great attention to personnel of different fields. In the courses of universities, in the research subjects of agriculture, forest and plant protection are commonly involved the soil animals. When a research program to started with, the first difficulty will be the accurate recognition of the different groups of soil animals.
The soil animals involve a wide range of animal groups, the specimens which extracted from each soil sample will be containing tens to hundreds small, different species of animals mixed together. How to accurately and conveniently separate them, that is an urgent problem awaiting solution. The key is a quick method for taxonomist to find out the species, but it is not applicable for the workers who are unfamiliar with the characteristics of the animals. The beautiful atlas for plants, animals or insects are good tools for species determination, but could not express the relationships between groups and the vertical pedigree.
After analyze the advantages and disadvantages of both the atlas and key, we considered that if combined the two in one, to form a "key of pictures", that will be easy for animal determination and at the same time to fined out their phylogenetic relationships. This "two combine into one" form book is really an urgent need new book for us. It will serves the professional taxonomists and also provide with a visual-aids, practical tool for the beginners.
In this book including the pictorial keys to soil Protozoa, Plathelminthes, Rotifera, Nemata, Mollusca, Tardigrada and Arthropoda. Totally concerns 8 animal phyla, 28 classes, 93 orders, 570 families and about 1 , 400 genera, which are arranged in systematic order. Besides the pictorial keys, a brief description of the main features, biology and geographical distributions of each group, are also provided. Therefore, this is an achievement in animal taxonomy and also a wide-ranging references for scientific workers of different spheres. Most of the pictures in this book were drawing from the identified specimens of different animal groups and their distribution places are according to the collecting data from different regions of China in the recent years.
The authors are very grateful to Academicians J. K. Liu and Y. Y. Chen, Prof. N. S. Tu for their encourage and support. We are also grateful to Academician C. T. Tang, Prof. Z. D. Fan, Prof. P. Y. Yu, Prof. K. L. Xia, Prof. H. Tamura and Dr. J. I. Ueno for checking parts of the manuscript. We would like to thank Mrs. Y., Zheng, Mr. S. M. Ma and the senior engineer Y. C. Cheng for ink over parts of the pictures. We would like to thank Mr. S. H. Hu and R. D. Xie for their editorial assistance. We would also like to thank Prof. Z. K. Lu for his warmly help and to Mr. F. Gao and F. Lee for their friendly advice on the manuscript.
This work was supported by National Natural Science foundation of China.
Mar. 18, 2000