Improving quantitative structure models of trees inspired by pipe and metabolic scaling theory

PurposeWe invent in this manuscript new tree parameters which can be derived from a single QSM. QSMs are topological ordered cylinder models of trees which describe the branching structure up to the tips. All new invented parameters have in common, that their defining point of view looks from the direction of the tips and not from the root along the tree. MethodsWe use new allometric power functions to predict the radius from the invented parameters. Then we improve the radii of the QMSs cylinders utilizing those functions. ResultsFor validation we use QSMs produced from an open point cloud data set of tree clouds with SimpleForest software. We compare the QSM volume against the harvested reference data for 65felled trees. We also found QSM data of TreeQSM, a competitive and broadly accepted QSM modeling tool. Our RMSE was less than 40 % of the TreeQSM RMSE. For other error measures, the r2adj. and the CCC, the relative improvement looked even better with reaching only 27 % and 21 % of the TreeQSM errors respectively. In a second validation part we show a way to run numerical tests against the West Brown Enquist (WBE) model. Expected power coefficients have been published for various allometric relations and we compare them to predicted values from QSM data. The deviation from the expected values ranges here from 8 % underestimation to 32 % overestimation. ConclusionsQuality - With the invention of the QSM radius filter technique we improve tree volume prediction capabilities utilizing QSMs. Quantity - More data can be collected with QSMs than with traditional methods.