The need for reliable prediction of species distributions dependent upon traits has been hindered by a lack of model transferability testing. We tested the predictive capacity of trait-SDMs by fitting hierarchical generalised linear models with three trait and four environmental predictors for 20 eucalypt taxa in a reference region. We used these models to predict occurrence for a much larger set of taxa and target areas (82 taxa across 18 target regions) in southeastern Australia. Median predictive performance for new species in target regions was 0.65 (area under receiver operating curve) and 1.24 times random (area under precision recall curve). Prediction in target regions did not worsen with increasing geographic, environmental or community compositional distance from the reference region, and was improved with reliable trait-environment relationships. Transfer testing also identified trait-environment relationships that did not transfer. These results give confidence that traits and transfer testing can assist in the hard problem of predicting environmental responses for new species, environmental conditions and regions.
Several Australian Riccia taxa have been sequenced for the first time, with the majority from the monsoon tropics of the Northern Territory, north of 18° latitude. This allowed testing of several infrageneric groupings within the genus as well as morphological species concepts. Molecular data from one nuclear and four plastid markers support the genus as a monophyletic group. However, the monophyly of the two largest subgenera, subgenus Riccia and subgenus Ricciella, are not supported, with the latter being polyphyletic and well nested within subgenus Riccia. Several currently accepted species such as Riccia inflexa and Riccia lamellosa were also found to be polyphyletic. A second tree reconstruction using only trnL–F sequences allowed comparison to several taxa collected outside of Australia. This showed that some species have a truly cosmopolitan distribution, whereas others have not.
Philotheca sect. Erionema includes 14 species from eastern Australia and one from south-western Australia. We conducted a phylogenetic analysis of the section, including samples of all species, using sequences of the ITS and ETS regions of nuclear ribosomal DNA. Results were broadly congruent with a previous analysis based on morphological and flavonoid data. The analysis is consistent with the monophyly of the section and supports the monophyly of six species represented by multiple samples. Philotheca verrucosa (A. Rich.) Paul G. Wilson was resolved as paraphyletic with respect to P. freyciana Rozefelds but with poor support. Philotheca glasshousiensis, P. myoporoides and P. myoporoides subsp. myoporoides were clearly polyphyletic, including separate geographic clades and the classification of each of these taxa requires revision. In particular, disjunct northern populations of P. glasshousiensis probably represent a distinct species, the five subspecies of P. myoporoides could be treated as separate species and at least two other distinct groups that are currently included under the circumscription of subsp. myoporoides could be treated as species. The phylogeny revealed deeply divergent, geographically overlapping clades in eastern Australia and substantial distances (up to 900 km) between sister taxa. We infer that biogeography of the group has been shaped largely by vicariant differentiation of taxa.
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