The grower can readily and cheaply provide these details by:
- Measuring a small but adequate sample of pruned trees to establish the DOS for each pruning lift;
- Assessing stem sweep in the pruned zone;
- Mapping the pruning boundary after each lift; and
- Having this information authenticated by an independent expert so that it is credible.
The Pruned Stand Certification (PSC) service has been introduced by Australian Forest Growers (AFG) to make this process possible.
How does it work?
Pruned Stand Certification can be applied to any species or any size or shape of stand or shelterbelt. Several small blocks can be considered as one stand if the effective pruning is the same. There is also a procedure for retrospective assessment if pruning has long since taken place. Once pruning has been carried out to a necessary minimum standard, the owner or owner's agent (e.g., consultant, silviculture operator) can do the following:
- Provide land description information. This is found, for instance, on rate demands or survey plans.
- Locate and measure a minimum of eight five-tree plots. On each tree, measure pruning lift, diameter at breast height (dbh) and if pruning is over 4.5 metres, significant sweep if present. Stocking is determined either from stocking plots or from between-planted-row and between tree measurements. To make the task easier, DOS is measured on just two trees per plot and the dish measures are used to adjust the estimated DOS (i.e., double sampling, a valid scientific procedure).
- Provide maps showing pruning boundary, plot locations, relocatable reference points, scale, and grid or magnetic north. The title plan or an aerial photograph is usually adequate for mapping purposes.