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AAIR Project No PL 94-2392
Source: Roger Dunham, Aberdeen University
DATE: 24/05/96
| user_name | Roger Dunham |
| user_organisation | Department of FORESTRY, Aberdeen University, 581 King Street, Aberdeen, Scotland |
| date | 24th May 1996 |
| model_name | Failure from compression wood |
| description | Describes probability of failure by snapping or overturning depending on proportion of stem occupied by compression wood |
| software | Excel 5.0 |
| operating_system | PC Windows |
| isumm | There are three input paramaters, two of which, height and dbh are currently redundant, but will probably be used in a future version of the model. Porportion of stem occupied by compression wood at breast height Measured from thin transverse section illuminated to show dark zones of compression wood. VALID ONLY FOR Sitka sprucena |
| ispecfile | Tree Height dbh compression wood proportion 1 23.5 28 33 |
| iexpspecfile | Height measured in metres, dbh in centimetres and compression wood percentage in % ALL DATA IN ONE FILE. |
| ivar1 | Height |
| ifile1 | input.xls |
| idescr1 | Tree height form stump to tip of highest branch or leader, |
| isensitiv1 | Unknown |
| isensdescr1 | none |
| ivar2 | dbh |
| ifile2 | input.xls |
| idescr2 | Tree diameter at beast height. |
| isensitiv2 | Unknown |
| isensdescr2 | none |
| ivar3 | compression wood percent |
| ifile3 | input.xls |
| idescr3 | Proportion of cross section occupied by compression wood |
| isensitiv3 | Unknown |
| isensdescr3 | none |
| csumm | None (Note from Marianne - Need regression coefficients etc here in this case) |
| cspecfile | NONE |
| cexpspecfile | n/a |
| osumm | Give probability of fialure by snap, overtuning or remaining undamaged |
| ospecfile | Not currently in file format |
| oexpspecfile | Probability of snap appears in column E, probability of windthrow in column F, and probability of no damage appears in column G. Column H contains most probable outcome. Probailities relate to likelihood of damage occurring if a similar storm occurred again, which originally caused the damage to the stand. |
| ovar1 | snapprob |
| ofile1 | excel spreadsheet model.xls, clumn E |
| odescr1 | Probability of snap |
| ovar2 | throwprob |
| ofile2 | Excel spreadsheet model.xls column F |
| odescr2 | Probability of windthrow |
| ovar3 | standprob |
| ofile3 | Excel spreasheet, model.xls, column G |
| odescr3 | Probability of remaining undamaged |
| stat_meth | compression wood proportion (Height and dbh will be included in future). Note from Marianne: what would need to go in here would be the parameters from any regressions carried out, information about the statistical relationships etc) |
| mech_meth | n/a |
| log_meth | n/a |
| scope | Limited to Sitka spruce grown in North of England. Develepod on 72 trees in two separet forests which had been badly wind damaged during winter of 1994/5 Modele should be used cautioulsy in other geographic areas., model is based on a restricted sample, and more data is needed to add confidence. Assumes that all trees were exposed to similar windloads. Soil types, silvicultural treatments, provenance etc, have not yet been investigated. |
| other | |
| copyright | DEPARTMENT OF FORESTRY, UNIVERSITY OF ABERDEEN |
| contact | Dr Roger Dunham |