Trait prediction accuracy does change due to spectral mixing and certain traits were more affected by mixing than others. Model effects were applied to mixed spectra containing various combinations of a target plant species and one, or multiple, other species to determine if, and at what amount of target species presence, spectral mixing significantly altered the trait prediction of the target species. Leaf spectroscopy of 23 plant species and the subsequent chemical derivation of 14 leaf traits enabled the creation of a species-inclusive partial least squares regression model for each trait (Validation R-2 = 0.28 – 0.85). Prediction accuracy is generally high when reflectance values are acquired from a single individual or species, however when the spectroscopy field of view is extended to include multiple species, the effects on predictive accuracy are less clear. We conclude thatīroom does not necessarily modify soil nitrogen availability but may deplete soil phosphorus availability and that broom invasionĬan be associated with increase of exotic species and/or the decline of native species.Īssociations between leaf chemicals and reflectance values using spectroscopy enables the modelling, and prediction of, individual functional traits. Finally, in greenhouse assays grass growth was not affected asĪ result of being grown with broom however, grasses appeared to produce more flowers when grown with broom. Species that were less abundant in the broom-invaded plots. At the other site, 60% of the plants that caused the differences between broom-invaded and un-invaded plots were native Plots were introduced species while native species abundances decreased in the broom-invaded plots compared to broom-free At one site, 60% of the plants whose abundances increased in the broom-invaded Plant diversity differed between two sites. With only a weak trend in increased soil nitrogen, but a significant decrease in soil phosphorus was observed. Had a greater impact on the growth of a native and an introduced grass compared to that of a native shrub. Finally we carried out greenhouse assays to test whether broom Of Scotch broom in changing conditions following its invasion.

We then looked for changes in patterns of diversity in the herbaceous community that might indicate a role The hypothesis that broom would increase available soil nitrogen by comparing soil nutrients in contiguous broom-invaded and Here, it is considered to be a threat to the native plant community. In Oregon, Washington, and British Columbia. Scotch broom (Cytisusscoparius), is a leguminous shrub, native to the Mediterranean, which has invaded most of the remaining Garry oak savannah ecosystems

Scotch broom plant