6

Community Analysis Package

2

Introduction

CAP

 (Community Analysis Package) is a Windows  program that offers a range

of analytical techniques commonly used by community ecologists. Researchers in

other fields such as palaeontology, archaeology and the social sciences also use

many of these methods. Programs to carry out many of these techniques have

long been available, but, they are often difficult to use as they were written for

main frame computers or PCs using DOS and they frequently have little or limited

graphical output. 

CAP

 has been designed for ease of use on PCs running under

Windows . Data can be organised using standard Windows programs such as

Excel and the output from 

CAP

 is displayed, exported and printed using standard

Windows techniques. This results in a program that is easily used by both

students and professional ecologists. It is particularly useful for ecological

teaching because it allows students to quickly enter data, try different

transformations and explore a range of methods within a familiar Windows

setting.

The input data set is arranged as a two dimensional array. In ecology it is usual

for the samples, which are normally collected from set localities and may be

called, for example, quadrates or stations, to form the columns. The variables for

each sample are the rows and usually comprise the numbers of each species or

other taxon observed. 

CAP

 does not include multivariate methods which seek to

understand the relationship between two sets of data as occurs when both

physical and biological data has been recorded for a number of samples.

However, two other Pisces programs, 

Ecom

103

 and 

Fuzzy Grouping

105

, are

designed for this type of data.

The methods on offer in CAP include both ordination methods such as Principal

Components Analysis (

PCA

53

) and Reciprocal Averaging (

RA

67

) and

classification methods such as 

TWINSPAN

70

 plus a wide range of clustering

procedures. Taken together they provide a powerful suite of methods with which

to explore, compare and analyse community structure. For all methods 

CAP

offers high quality graphical and tabulated output which is organised into tabbed

notebooks. The program will run on Apple machines with PC emulation software.

CAP

 uses the same data structure as 

Species Diversity and Richness II

103

 which

calculates a wide range of diversity and species richness measures. Together

with 

Ecom

103

 and 

Fuzzy Grouping

105

, the programs offer a very extensive range

of methods for the analysis of ecological communities.

To help users to understand how to use 

CAP,

 the instructions are written from an

ecological viewpoint. We generally refer to columns as samples or quadrates and

rows as species. This is the way an ecological data set should be organised to

study both the relationship and similarity between samples and the pattern of

association between species. Techniques such as PCA can be used on any data

set of observations for each of which there are a number of variables.

CAP 3.0 was released in June 2004.

CAP 3.0 was developed and produced by Richard Seaby, Peter Henderson, John

Prendergast and Robin Somes.

Copyright 2004, PISCES CONSERVATION LTD