Difference between revisions of "Arne Pommerening's Forest Biometrics & Quantitative Ecology Lab"

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CRANCOD - A program for the analysis and reconstruction of spatial forest structure

About CRANCOD

It is widely acknowledged that spatial forest structure is a driving factor behind growth processes and that forest growth, in return, influences the structural composition of woodlands. Also any impact on forests is primarily a change of spatial forest structure.

In the last few decades an impressive number of structural indices have been developed to quantify spatial forest structure and it has also been suggested that they can be used as surrogate measures for quantifying biodiversity (Pommerening, 2002). Of particular interest in this regard is the development of a family of individual tree neighbourhood-based indices, which are measures of small-scale variations in tree positions, species and dimensions, developed by Gadow and colleagues (Gadow and Hui, 2002). Especially when expressed as frequency distributions these indices offer valuable information on spatial woodland structure.

The CRANCOD program is a scientific laboratory for analysing and experimenting with structural indices. CRANCOD has been designed for use with large research plots with full enumeration of trees but in addition offers the opportunity to analyse complete inventory data consisting of multiple sample plots of circular or rectangular shape and varying plot size based on a systematic grid. The program has in built flexibility with the user able to select the number of neighbour trees and choose between six different methods of edge correction. CRANCOD can even be used to analyse research plots/inventories for which spatial information has not been recorded.

The CRANCOD program is a scientific laboratory for analysing and experimenting with structural indices. CRANCOD has been designed for use with large research plots with full enumeration of trees but in addition offers the opportunity to analyse complete inventory data consisting of multiple sample plots of circular or rectangular shape and varying plot size based on a systematic grid. The program has in built flexibility with the user able to select the number of neighbour trees and choose between six different methods of edge correction. CRANCOD can even be used to analyse research plots/inventories for which spatial information has not been recorded. The integrative sampling simulator ISIS allows the simulation of systematic inventories with varying plot geometry. Saving individual tree results in addition to the summary files enables you to carry out individual tree based follow-up investigations. A special visualisation tool allows the user to visually explore structural indices. Tree species codings and colours can be flexibly edited externally. A number of language options allow optimal adaptation of the program in different countries.

As with any Java application CRANCOD can also be used on Unix, Linux and Macintosh computers. The philosophy and objectives of the program are described in greater detail in Pommerening (2006). This core version of CRANCOD is a public domain software. However, the program is protected by intellectual property rights and users are expected to acknowledge CRANCOD and its author when publishing results. The programming work of CRANCOD has been optimised towards the efficient and correct computation of scientifically interesting summary statistics. In order to achieve this less importance has been given to creating user-friendly interfaces, messages and warnings. This manual shares the same philosophy. This, however, could change in the future as part of collaborations with interested partners or companies.

Author and copyrights: Prof. Dr. Arne Pommerening, Bern University of Applied Sciences, School of Agricultural, Forest and Food Sciences. Email: arne.pommerening@bfh.ch

Software version: 1.3