@article {811,
	title = {Spatial patterns of endemic plants in California},
	journal = {Natural Areas Journal},
	volume = {29},
	year = {2009},
	month = {2009},
	pages = {344-366},
	abstract = {California endemic vascular plant range patterns were quantified using a flora-based geodatabase technique that combined species presence in geographic areas and elevation band occupation. Resulting species range maps were summarized by 228 geographic areas. Over 60\% of the endemic species range size distributions were found to have range sizes less than 10,000 km2. The largest endemic taxon range was 275,749 km2, or 67\% of the state. California endemic plants had different distribution patterns depending on the criteria used to portray them. California{\textquoteright}s Central Coast Ranges, Sierra Nevada foothills, high elevation Sierra Nevada Mountains, Channel Islands, San Jacinto Mountains, Napa and Lake Counties, Inyo Mountains, sections of the Mojave Desert, and San Bernardino Mountains were all identified as areas with unique endemic plant attributes. We compared endemic species richness between map units in zones that have similar topography and climate, and found that area only weakly correlated with species richness, suggesting other factors have stronger influence on endemism in continental California. The findings have implications for developing conservation plans that target endemic species. In particular, we identify areas of the state, previously de-emphasized, that deserve greater recognition based on the characteristics of their restricted endemic plants. Range distribution estimates produced from floral keys made digital proved effective in this study, an inexpensive approach that could be implemented in other regions of the world for which floras have been published.},
	keywords = {endemism, flora, geodatabase, hotspots, Plant biogeography, range size},
	url = {http://www.naturalarea.org/journaltoc.aspx?p=154},
	author = {Thorne, J. H. and Viers, J. H. and Price, J. and Stoms, D. M.}
}
@article {753,
	title = {Human impacts, plant invasion, and imperiled plant species in California},
	journal = {Ecological Applications},
	volume = {16},
	year = {2006},
	month = {2006},
	pages = {1338-1350},
	abstract = {Invasive species are one of the fastest growing conservation problems. These species homogenize the world{\textquoteright}s flora and fauna, threaten rare and endemic species, and impose large economic costs. Here, we examine the distribution of 834 of the more than 1000 exotic plant taxa that have become established in California, USA. Total species richness increases with productivity; however, the exotic flora is richest in low-lying coastal sites that harbor large numbers of imperiled species, while native diversity is highest in areas with high mean elevation. Weedy and invasive exotics are more tightly linked to the distribution of imperiled species than the overall pool of exotic species. Structural equation modeling suggests that while human activities, such as urbanization and agriculture, facilitate the initial invasion by exotic plants, exotics spread ahead of the front of human development into areas with high numbers of threatened native plants. The range sizes of exotic taxa are an order of magnitude smaller than for comparable native taxa. The current small range size of exotic species implies that California has a significant {\textquoteleft}{\textquoteleft}invasion debt{\textquoteright}{\textquoteright} that will be paid as exotic plants expand their range and spread throughout the state.},
	keywords = {California, dispersal, exotic plants, extinction, global biodiversity hotspot, habitat loss, invasive species, rare species, species richness, structural equation models},
	url = {http://www.esajournals.org/esaonline/?request=get-abstract\&issn=1051-0761\&volume=016\&issue=04\&page=1338},
	author = {Seabloom, E. W. and Williams, J. W. and Slayback, D. and Stoms, D. M. and Viers, J. H. and Dobson, A. P.}
}
@article {832,
	title = {Anthropogenic impacts upon plant species richness and NPP in California},
	journal = {Ecology Letters},
	volume = {8},
	year = {2005},
	month = {2005},
	pages = {127-137},
	abstract = {We assess the importance of anthropogenic land-use, altered productivity, and species invasions for observed productivity-richness relationships in California. To this end, we model net primary productivity (NPP) c. 1750 AD and at present (1982-1999) and map native and exotic vascular plant richness for 230 subecoregions. NPP has increased up to 105\% in semi-arid areas and decreased up to 48\% in coastal urbanized areas. Exotic invasions have increased local species diversity up to 15\%. Human activities have reinforced historical gradients in species richness but reduced the spatial heterogeneity of NPP. Structural equation modelling suggests that, prior to European settlement, NPP and richness were primarily controlled by precipitation and other abiotic variables, with NPP mediating richness. Abiotic variables remain the strongest predictors of present NPP and richness, but intermodel comparisons indicate a significant anthropogenic impact upon statewide distributions of NPP and richness. Exotic and native species each positively correlate to NPP after controlling for other variables, which may help explain recent reports of positively associated native and exotic richness.},
	keywords = {California, human impacts, Land cover change, net primary productivity, species richness, structural equation models},
	url = {<Go to ISI>://000226491200001},
	author = {Williams, J. W. and Seabloom, E. W. and Slayback, D. and Stoms, D. M. and Viers, J. H.}
}
