Range size, taxon age and hotspots of neoendemism in the California flora

Aim  Sustaining biological diversity requires the protection of the ecological, evolutionary and landscape-level processes that generate it. Here, we identify areas of high neoendemism in a global diversity hotspot, the California flora, using range size data and molecular-based estimates of taxon age. Location  California, USA. Methods  We compiled distribution and range size data for all plant taxa endemic to California and internal transcribed spacer (ITS)-based age estimates for 337 putative neoendemics (15% of the endemic flora). This information was combined to identify areas in the state with high proportions of young and restricted-range taxa. We overlaid the distribution of neoendemic hotspots on maps of currently protected lands and also explored correlations between our diversity measures and climate. Results  The central coast of California, the Sierra Nevada and the San Bernardino Range contained endemics with the most restricted distributions on average, while areas in the Desert and Great Basin provinces found within the state were composed of the youngest neoendemics on average. Diversity measures that took age and range size into account shifted the estimate of highest endemic diversity in the state towards the Desert and Great Basin regions relative to simple counts of endemic species richness. Our diversity measures were poorly correlated with climate and topographic heterogeneity. Main conclusions  Substantial portions of California with high levels of plant neoendemism fall outside of protected lands, indicating that additional action will be needed to preserve the geographic areas apparently associated with high rates of plant diversification. The neoendemic flora of the deserts appears particularly young in our analyses, which may reflect the relatively recent origin of desert environments within the state.

[1]  K. Kay,et al.  A survey of nuclear ribosomal internal transcribed spacer substitution rates across angiosperms: an approximate molecular clock with life history effects , 2006, BMC Evolutionary Biology.

[2]  B. G. Baldwin.  ORIGIN OF THE SERPENTINE‐ENDEMIC HERB LAYLA DISCOIDEA FROM THE WIDESPREAD L. LANDULOSA (COMPOSITAE) , 2005, Evolution; international journal of organic evolution.

[3]  M. Nei,et al.  Estimation of the number of nucleotide substitutions in the control region of mitochondrial DNA in humans and chimpanzees. , 1993, Molecular biology and evolution.

[4]  R. J. Bayer,et al.  Molecular phylogeny, diversification and character evolution in Lupinus (Fabaceae) with special attention to Mediterranean and African lupines , 2004, Plant Systematics and Evolution.

[5]  R. Pennington,et al.  Systematics and biogeography of Lathyrus (Leguminosae) based on internal transcribed spacer and cpDNA sequence data. , 2005, American journal of botany.

[6]  T. Nagamine,et al.  A Molecular Phylogeny of Lilium in the Internal Transcribed Spacer Region of Nuclear Ribosomal DNA , 1999, Journal of Molecular Evolution.

[7]  J. Porter,et al.  EVOLUTIONARY DIVERSIFICATION AND ADAPTATION TO NOVEL ENVIRONMENTS IN NAVARRETIA (POLEMONIACEAE) , 1997 .

[8]  Daniel F. Austin,et al.  The Jepson Desert Manual: Vascular Plants of Southeastern California , 2003 .

[9]  Sudhir Kumar,et al.  MEGA3: Integrated software for Molecular Evolutionary Genetics Analysis and sequence alignment , 2004, Briefings Bioinform..

[10]  R. Calsbeek,et al.  Patterns of molecular evolution and diversification in a biodiversity hotspot: the California Floristic Province , 2003, Molecular ecology.

[11]  G. Spicer,et al.  Phylogenetic Relationships within Phacelia subgenus Phacelia (Hydrophyllaceae) Inferred From Nuclear rDNA ITS Sequence Data , 2005 .

[12]  David M. Stoms,et al.  Spatial Patterns of Endemic Plants in California , 2009 .

[13]  R. Schmid,et al.  Inventory of Rare and Endangered Vascular Plants of California , 1994 .

[14]  D. Soltis,et al.  Phylogenetic Relationships within Lithophragma (Saxifragaceae): Hybridization, Allopolyploidy, and Ovary Diversification , 1999 .

[15]  P. Raven,et al.  Origin and Relationships of the California Flora , 1978 .

[16]  Craig Moritz,et al.  Strategies to protect biological diversity and the evolutionary processes that sustain it. , 2002, Systematic biology.

[17]  P. Munz,et al.  A California Flora , 1960 .

[18]  B. G. Baldwin,et al.  Reexamination of relationships, habital evolution, and phylogeography of checker mallows (Sidalcea; Malvaceae) based on molecular phylogenetic data. , 2003, American journal of botany.

[19]  Shawn W. Laffan,et al.  Endemism in the Australian flora , 2001 .

[20]  M. Sanderson,et al.  Evidence on the monophyly of Astragalus (Fabaceae) and its major subgroups based on nuclear ribosomal DNA ITS and chloroplast DNA trnL intron data , 1999 .

[21]  T. Erwin.  An evolutionary basis for conservation strategies. , 1991, Science.

[22]  J. C. Hickman,et al.  The Jepson Manual: Higher Plants of California , 1993 .

[23]  B. G. Baldwin,et al.  Phylogeny of Stephanomeria and related genera (compositae-lactuceae) based on analysis of 18S-26S nuclear rDNA ITS and ETS sequences. , 2002, American journal of botany.

[24]  James B Grace,et al.  Biogeographic Affinity Helps Explain Productivity‐Richness Relationships at Regional and Local Scales , 2007, The American Naturalist.

[25]  C. Chamberlain,et al.  Reconstructing the paleotopography of mountain belts from the isotopic composition of authigenic minerals , 2000 .

[26]  D. Soltis,et al.  Phylogenetic relationships in Ribes (Grossulariaceae) inferred from ITS sequence data. , 2003 .

[27]  D. Soltis,et al.  Diversification of the North American shrub genus Ceanothus (Rhamnaceae): conflicting phylogenies from nuclear ribosomal DNA and chloroplast DNA. , 2000, American journal of botany.

[28]  B. G. Baldwin.  Phylogenetic utility of the internal transcribed spacers of nuclear ribosomal DNA in plants: an example from the compositae. , 1992, Molecular phylogenetics and evolution.

[29]  D. Ackerly,et al.  Climate Change and the Future of California's Endemic Flora , 2008, PloS one.

[30]  D. Faith.  Conservation evaluation and phylogenetic diversity , 1992 .

[31]  R. Olmstead,et al.  Patterns of evolution in western North American Mimulus (Phrymaceae). , 2004, American journal of botany.

[32]  D. I. Axelrod.  History of the Mediterranean Ecosystem in California , 1973 .

[33]  M. Donoghue,et al.  Erratum: The ITS region of nuclear ribosomal DNA: A valuable source of evidence on angiosperm phylogeny (Annals of the Missouri Botanical Garden (1995) 82 (247-277)) , 1996 .

[34]  B. G. Baldwin,et al.  Phylogeny and ecological radiation of New World thistles (Cirsium, Cardueae – Compositae) based on ITS and ETS rDNA sequence data , 2002, Molecular ecology.

[35]  Peter J. Richerson,et al.  Patterns of Plant Species Diversity in California: Relation to Weather and Topography , 1980, The American Naturalist.

[36]  J. Viers,et al.  CalJep: A Spatial Distribution Database of CalFlora and Jepson Plant Species , 2006 .

[37]  R. Ornduff,et al.  Goldfields Revisited: A Molecular Phylogenetic Perspective on the Evolution of Lasthenia (Compositae: Heliantheae sensu lato) , 2001, International Journal of Plant Sciences.

[38]  R. Mittermeier,et al.  Biodiversity hotspots for conservation priorities , 2000, Nature.

[39]  J. Janovec,et al.  Inferred Phylogeny in Keckiella (Scrophulariaceae) based on Noncoding Chloroplast and nuclear ribosomal DNA Sequences , 2009 .

[40]  Paul H. Williams,et al.  Measuring biodiversity for choosing conservation areas. , 1993 .

[41]  Richard Grenyer,et al.  Preserving the evolutionary potential of floras in biodiversity hotspots , 2007, Nature.

[42]  Aaron Liston,et al.  Molecular phylogenetics of the clover genus (Trifolium--Leguminosae). , 2006, Molecular phylogenetics and evolution.

[43]  Peter C. Hoch,et al.  A Phylogenetic Analysis of Epilobium (Onagraceae) Based on Nuclear Ribosomal DNA Sequences , 1994 .

[44]  Hans Peter Linder,et al.  Plant diversity and endemism in sub‐Saharan tropical Africa , 2001 .

[45]  S. Kalisz,et al.  Comparative analysis of late floral development and mating-system evolution in tribe Collinsieae (Scrophulariaceae s.l.). , 2002, American journal of botany.

[46]  D. Happold.  Packrat Middens. The Last 40,000 Years of Biotic Change , 1991 .

[47]  J. Bowman,et al.  Molecular evidence for bicontinental hybridogenous genomic constitution in Lepidium sensu stricto (Brassicaceae) species from Australia and New Zealand. , 2004, American journal of botany.

[48]  Jack Major,et al.  Endemism and Speciation in the California Flora , 1965 .

[49]  J. Watson,et al.  Conservation Biogeography: assessment and prospect , 2005 .

[50]  S. Farmer.  Phylogenetic Analyses and Biogeography of Trilliaceae , 2006 .

[51]  A. Desrochers,et al.  Edaphic races and phylogenetic taxa in the Lasthenia californica complex (Asteraceae: Heliantheae): an hypothesis of parallel evolution , 2003, Molecular ecology.

[52]  C. Bell,et al.  Molecular phylogeny and biogeography of Linanthus (Polemoniaceae). , 2000, American journal of botany.

[53]  V. T. Parker,et al.  TWO LINEAGES OF ARCTOSTAPHYLOS (ERICACEAE) IDENTIFIED USING THE INTERNAL TRANSCRIBED SPACER (ITS) REGION OF THE NUCLEAR GENOME , 2005 .

[54]  M. Arroyo,et al.  Elucidating deep-level phylogenetic relationships in Saxifragaceae using sequences for six chloroplastic and nuclear DNA regions , 2001 .

[55]  T. Stuessy,et al.  Phylogeny of holoparasitic Orobanche (Orobanchaceae) inferred from nuclear ITS sequences. , 2004, Molecular phylogenetics and evolution.

[56]  Craig Moritz,et al.  The California Hotspots Project: identifying regions of rapid diversification of mammals , 2008, Molecular ecology.

[57]  P. Munz.  Supplement to A California Flora , 2023 .

[58]  James C. Hickman,et al.  The Jepson Manual: Higher Plants of California , 1993 .

[59]  M. Donoghue,et al.  Rates of Molecular Evolution Are Linked to Life History in Flowering Plants , 2008, Science.

[60]  Michael J. Sanderson,et al.  Erratum: The ITS Region of Nuclear Ribosomal DNAZ: A Valuable Source of Evidence on Angiosperm Phylogeny , 1995 .

[61]  Robert N. Fisher,et al.  Are hotspots of evolutionary potential adequately protected in southern California , 2008 .

[62]  B. G. Baldwin,et al.  Higher-Level Relationships and Major Lineages of Lessingia (Compositae, Astereae) Based on Nuclear rDNA Internal and External Transcribed Spacer (ITS and ETS) Sequences , 2001 .

[63]  Charles H. Cannon,et al.  Systematics of Fagaceae: Phylogenetic Tests of Reproductive Trait Evolution , 2001, International Journal of Plant Sciences.

[64]  David D. Ackerly,et al.  Evolution, origin and age of lineages in the Californian and Mediterranean floras , 2009 .

[65]  Ronald D. Lewis.  Fossil Crinoids , 2000 .

[66]  C. Wilson,et al.  Phylogenetic Relationships in Iris Series Californicae Based on ITS Sequences of Nuclear Ribosomal DNA , 2003 .

[67]  B. G. Baldwin,et al.  A Phylogenetic Study of Sanicula sect. Sanicoria and S. sect. Sandwicenses (Apiaceae) Based on Nuclear rDNA and Morphological Data , 1999 .