Premise: There are relatively few studies of flower color at landscape scales that can address the relative importance of competing mechanisms (e.g., biotic: pollinators; abiotic: ultraviolet radiation, drought stress) at landscape scales.
View Article and Find Full Text PDFThe lowland Amazon rainforest houses some of the greatest tree diversity on Earth. While the vast majority of these species are rare, a small number are common and widespread and thus considered to play a disproportionate role in many of the global ecosystem services provided by the Amazon. However, the extent to which dominant Amazonian tree species actually include multiple clades, each on their own unique evolutionary trajectory, is unknown.
View Article and Find Full Text PDFBird nests in natural history collections are an abundant yet vastly underutilized source of genetic information. We sequenced the nuclear ribosomal internal transcribed spacer to identify plant species used as nest material in two contemporary (2003 and 2018) and two historical (both 1915) nest specimens constructed by Song Sparrows (Melospiza melodia) and Savannah Sparrows (Passerculus sandwichensis). A total of 13 (22%) samples yielded single, strong bands that could be identified using GenBank resources: six plants (Angiospermae), six green algae (Chlorophyta), and one ciliate (Ciliophora).
View Article and Find Full Text PDFPremise: Bryophytes (mosses, liverworts, and hornworts) tend to have very large geographic ranges, which impedes progress toward understanding the drivers of diversification and extinction. This study aimed to investigate whether North American endemics differ geographically from more widespread species and whether differences in climatic niche or traits related to dispersal and establishment differ between endemics and more widespread species.
Methods: All available herbarium records of bryophytes from North America north of Mexico (10 collections) were used.
Peat mosses (Sphagnum) hold exceptional importance in the control of global carbon fluxes and climate because of the vast stores of carbon bound up in partially decomposed biomass (peat). This study tests the hypothesis that the early diversification of Sphagnum was in the Northern Hemisphere, with subsequent range expansions to tropical latitudes and the Southern Hemisphere. A phylogenetic analysis of 192 accessions representing the moss class Sphagnopsida based on four plastid loci was conducted in conjunction with biogeographic analyses using BioGeoBEARS to investigate the tempo and mode of geographic range evolution.
View Article and Find Full Text PDFFrullania subgenus Microfrullania is a clade of ca. 15 liverwort species occurring in Australasia, Malesia, and southern South America. We used combined nuclear and chloroplast sequence data from 265 ingroup accessions to test species circumscriptions and estimate the biogeographic history of the subgenus.
View Article and Find Full Text PDFPremise Of The Study: Identifying regions of high endemism is a critical step toward understanding the mechanisms underlying diversification and establishing conservation priorities. Here, we identified regions of high moss endemism across North America. We also identified lineages that contribute disproportionately to endemism and document the progress of efforts to inventory the endemic flora.
View Article and Find Full Text PDFUnderstanding the links between intraspecific genetic variation and patterns of diversity in associated communities has been the primary focus of community genetics or 'genes-to-ecosystem' research in ecology. While other ecological factors, such as the abiotic environment, have well-documented influences on communities, the relative contributions of genetic variation versus the environment to species interactions remains poorly explored. In this study, we use a common garden experiment to study a coastal dune plant community dominated by the shrub, Baccharis pilularis, which displays a morphological dimorphism in plant architecture.
View Article and Find Full Text PDFMol Phylogenet Evol
June 2012
Cryptic lineage diversification is an important component of global biodiversity, but it presents challenges to our ability to catalog and understand that diversity. Because of their relative morphological simplicity and broad geographic distributions, bryophytes are an ideal study group for investigating this phenomenon. This study generated molecular data from 109 ingroup individuals to test morphological species circumscriptions and examine patterns of cryptic lineage diversification within the small north temperate moss genus Scleropodium (Brachytheciaceae).
View Article and Find Full Text PDFThe flora of California, a global biodiversity hotspot, includes 2387 endemic plant taxa. With anticipated climate change, we project that up to 66% will experience >80% reductions in range size within a century. These results are comparable with other studies of fewer species or just samples of a region's endemics.
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