Dasiphora

Abstract: The extent of endomycorrhizal colonization of Dasiphora floribunda was measured in 8 calcareous wetlands in eastern New York State, USA. Environmental parameters (pH, conductivity, water-table depth, soil moisture, soil organic matter, soil NH4+, soil available P, and porewater DIP) varied among wetlands. Soil available P was relatively low and ranged from 2.52 to 15.74 mg-P gdw−1 in all 8 wetlands. Contrary to expectation, the extent of endomycorrhizal colonization of D. floribunda did not vary among calcareous wetlands of different soil phosphorus or moisture status. Mycorrhizal colonization of D. floribunda ranged from 66.7 to 91.7%, with an average of 78.1 ± 7.7%. Although environmental parameters were only measured once, these results suggest that soil available P and soil moisture, used to predict variation of endomycorrhizal colonization of other wetland plants, are not useful for predicting the extent of endomycorrhizal colonization of D. floribunda. We propose that calcareous wetlands in...

Abstract: Plateau uprisings and climatic oscillations are considered to have caused extensive allopatric divergences that account for the rich species diversity of the Qinghai-Tibetan Plateau (QTP). However, secondary contact during range shifts in the Quaternary glacial cycles or inter-uplift stages may have restored the gene flow between species and so counteracted these divergences, particularly in rapidly-adapting dominant elements. We tested this hypothesis by determining the phylogeographical history of Dasiphora (Rosaceae), a genus of two species that are widely distributed on the QTP and co-exist in numerous localities. We sequenced two chloroplast DNA fragments (rbcL, trnT-L) for 559 individuals from 87 populations. Bayesian methods were used to identify phylogenetic relationships and to estimate divergence times. Demographic histories were inferred using neutrality tests, mismatch distribution analysis, and coalescent simulation. A total of 112 haplotypes that clustered into three major groups were identified. The formation of these groups and their subgroups was dated to between the Pliocene and the late Pleistocene. In addition, we found that some groups underwent multiple extensive expansions. Species-specific haplotypes were identified for each species, although these haplotypes phylogenetically intermixed. These results suggest that recent plateau uplifts and climatic oscillations might have caused the deep divergences observed within this genus. However, later range expansions probably blurred these divergences and possible species boundaries. Our results shed new light on the complex evolutionary history of the QTP alpine plants. (c) 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 777-788.

Abstract: Fluvial mine tailing deposition has caused extensive riparian damage throughout the western USA. Willows are often used for fluvial mine tailing revegetation, but some accumulate excessive metal concentrations potentially detrimental to browsers. This greenhouse experiment evaluated growth and metal accumulation of Geyer willow (Salix geyeriana Andersson), Drummond’s willow (Salix drummondiana Barratt ex Hook.), diamondleaf willow (Salix planifolia Pursh), Bebb willow (Salix bebbiana Sarg.), thinleaf alder [Alnus incana (L.) Moench spp. tenuifolia (Nutt.) Breitung], water birch (Betula occidentalis Hook.), red-osier dogwood (Cornus sericea L. spp. sericea), and shrubby cinquefoil [(Dasiphora fruticosa (L.) Rydb. ssp. floribunda (Pursh) Kartesz)]. Bare-root shrubs were grown in tailings collected from three acidic, metal-contaminated (i.e., Cd, Cu, Pb, and Zn) fluvial deposits near Leadville, Colorado, USA. Tailings were amended with only lime to raise the soil pH to 7 s.u., or with lime and composted biosolids (224 Mg ha−1). All shrubs survived in the amended tailings; composted biosolids had little effect on plant biomass. Aboveground and belowground biomass increased during the 2-month greenhouse study by 3–9 and 1.5–5 times initial values, respectively. Most shrubs accumulated Pb and Cu in roots, and belowground Pb concentrations in all shrubs were significantly reduced by the addition of composted biosolids. Compared to other species, alder and cinquefoil accumulated Pb in aboveground growth, and concentrations exceeded animal toxicity thresholds, but these shrubs normally comprise a small proportion of animal diets. Dogwood, alder, and cinquefoil contained low Cd concentrations in aboveground new growth, whereas Bebb and Geyer willow contained zootoxic concentrations. Dogwood, alder, and cinquefoil are three good candidates for mine tailing revegetation, especially in fluvial deposits with elevated Cd concentrations.

Abstract: The genera Argentina J. Hill, Pentaphylloides Duhamel, nom. illeg'. (=Dasiphora Rafin.) and Duchesnea Smith are treated as congeneric synonyms of Potentilla L. sens, stricto ; nine subgenera are recognised with keys to their identification and nomenclatural set up. The origin of the genus Potentilla L. is discussed and evolutionary trends within the subgencra hypothesized.