Soil Arthropod Sampling
A. M A C F A D Y E N
Department of Zoology, University College, Swansea
I. Introduction ........................................................
1
Survey ..............................................................
2
111. The Design and Execution of a Survey ..................................
6
11. Characteristic Sampling Requirements of some Different types of Soil Arthropod
A. S~tistical Aspects ..................................................
6
B. Laboratory Methods for Counting and Recording ......................
9
B. Behaviour-Typenlethods ............................................
12
IV. A Survey of Available Examination and Separation Processes .............. 1 1
A. The Examination of Soil with Animals in situ ..........................
11
C. Mechanical Separation Methods taking advantage of DifTerential Physical
Properties of Animals and the Substratum .............................. 21
V. The Choice of Complete Sampling Systems for Specific Purposes ............ 20
References ..............................................................
31
VI. Summary and Conclusions.
"' )
.............................................
_.
I. INTRODUCTION
In response to the editor's suggestion this article is intended to provide
practical advice on how to obtain efficient estimates of numbers of soil
arthropods. The attainable efficiency of any sampling scheme depends
greatly on the aims of the investigation, a truism which applies particularly to soil fauna surveys because in such work sampling effort increases
steeply with the accuracy demanded. The need for the biologist to
balance most carefully his demands in terms of accuracy and taxonomic
range against resources of time and equipment is the more acute when
he studies unevenly distributed populations, many of them belonging to
groups whose taxonomy is, even m w , rudimentary and possessing such
a wide range of size, density and biological characteristics that the
simultaneous sampling of all groups is quite impracticable. Secondly,
such a variety of devices for extracting and collecting soil arthropods
has already been described (see, for instance Balogh, 1958; Kevan,
1955; Kuhnelt, 196l), that the novice is at a loss to know which methods
are appropriate to his own work. Some of these are intended, or can be
used, only for qualitative work, others apply only to a very limited
range of organisms and, despite the excellent reviews mentioned, there
appears to be a need for a systematic treatment devoted to the two
themes mentioned, namely experimental design and choice of extracting and collecting methods.
A
1
E.R.-1
A. M A C F A D Y E N
Department of Zoology, University College, Swansea
I. Introduction ........................................................
1
Survey ..............................................................
2
111. The Design and Execution of a Survey ..................................
6
11. Characteristic Sampling Requirements of some Different types of Soil Arthropod
A. S~tistical Aspects ..................................................
6
B. Laboratory Methods for Counting and Recording ......................
9
B. Behaviour-Typenlethods ............................................
12
IV. A Survey of Available Examination and Separation Processes .............. 1 1
A. The Examination of Soil with Animals in situ ..........................
11
C. Mechanical Separation Methods taking advantage of DifTerential Physical
Properties of Animals and the Substratum .............................. 21
V. The Choice of Complete Sampling Systems for Specific Purposes ............ 20
References ..............................................................
31
VI. Summary and Conclusions.
"' )
.............................................
_.
I. INTRODUCTION
In response to the editor's suggestion this article is intended to provide
practical advice on how to obtain efficient estimates of numbers of soil
arthropods. The attainable efficiency of any sampling scheme depends
greatly on the aims of the investigation, a truism which applies particularly to soil fauna surveys because in such work sampling effort increases
steeply with the accuracy demanded. The need for the biologist to
balance most carefully his demands in terms of accuracy and taxonomic
range against resources of time and equipment is the more acute when
he studies unevenly distributed populations, many of them belonging to
groups whose taxonomy is, even m w , rudimentary and possessing such
a wide range of size, density and biological characteristics that the
simultaneous sampling of all groups is quite impracticable. Secondly,
such a variety of devices for extracting and collecting soil arthropods
has already been described (see, for instance Balogh, 1958; Kevan,
1955; Kuhnelt, 196l), that the novice is at a loss to know which methods
are appropriate to his own work. Some of these are intended, or can be
used, only for qualitative work, others apply only to a very limited
range of organisms and, despite the excellent reviews mentioned, there
appears to be a need for a systematic treatment devoted to the two
themes mentioned, namely experimental design and choice of extracting and collecting methods.
A
1
E.R.-1