Content uploaded by Sula Vanderplank
Author content
All content in this area was uploaded by Sula Vanderplank on Jun 14, 2017
Content may be subject to copyright.
A preview of the PDF is not available
PLANT DIVERSITY AND ENDEMISM IN THE CALIFORNIA FLORISTIC PROVINCE
Abstract
The California Floristic Province (CFP) is an area of high biodiversity and endemism corresponding roughly to the portion of western North America having a Mediterranean-type climate. High levels of diversity and endemism in the CFP are attributed to the unique geo-climatic setting of the region. In recent years, much has been learned about the origins of plant diversity in western North America. This work, however, has been hindered by a focus on political rather than biotic regions, such that much more is known about diversity and endemism in the state of California than the natural biotic region represented by the CFP. Here we present a preliminary list of native land plants (vascular plants and bryophytes) found in the CFP, as well as an analysis of diversity and endemism patterns at the level of both species and minimum rank taxa (MRT; species and infraspecific taxa). A total of 6,927 MRT are native to the CFP, including 6,143 vascular plants and 784 bryophytes. Of these, 2,612 vascular plants are endemic to the CFP (42%) compared to 37 endemic bryophytes (5%). Finally, 2,506 native CFP vascular plant MRT (41% of the CFP flora) and 454 CFP bryophyte MRT (58% of the CFP flora) are found outside California in the Oregon and Baja California parts of the CFP. This high degree of sharing across political boundaries among both vascular plants and bryophytes highlights the cohesiveness of the CFP, and the need to focus more research effort on biotic regions.
... Floristic provinces are defined by phytogeographic and climatic factors (Raven and Axelrod 1978;Burge et al. 2016). At the broadest level, the study area is contained within the CFP (Jepson Flora Project, 2022). ...
... At the broadest level, the study area is contained within the CFP (Jepson Flora Project, 2022). The CFP is located along the Pacific coast of western North America and is characterized by a Mediterranean climate and relatively high rates of species richness and endemism (Burge et al. 2016;Stebbins and Major 1965;Raven and Axelrod 1978), so much so that it has been designated as a global biodiversity hotspot (Myers 1990 (Meyer 1978). Plant distributions are likely to change in conjunction with the current changing climate regime. ...
The Manter and Salmon Creek watersheds occur in the southern Sierra Nevada, Tulare County, CA. The study area encompasses 132 sq. km. (51 sq. mi.) on the Kern Plateau. There are several aspects of this region that make it worthy of botanical exploration, including the presence of numerous endemic (e.g., Pinus balfouriana subsp. austrina, Eriogonum polypodum) and rare taxa (e.g., Eriogonum breedlovei var. shevockii, Carlquistia muirii). In addition, the Domeland Wilderness, which makes up 65 sq. km. (25 sq. mi.) or ca. 50% of the study area, has had little formal documentation of plant diversity. Documenting this diversity in the present time is vital because there are several impacts to the flora from land use and climate change. Cattle grazing, off highway vehicle use, logging, long-term drought, and the impacts from a changing fire regime were all documented at the area. These disturbances may have a lasting impact on the flora.
As a part of this study, I completed a total of 24 field trips, totaling 86 field days, that resulted in the collection of 1,412 plant specimens. A total of 590 minimum-rank taxa were documented in the study area, representing 78 families and 270 genera. Of the minimum-ranked taxa, 34 are non-native and 28 have conservation status. Angelica callii, a California endemic with a California Rare Plant Ranking of 4.3, was newly documented in the study area, representing an eastward range extension of 26 km (16 mi). The results include a complete description of vegetation and habitats, as well as an annotated checklist with descriptions of local abundance, habitat types, and a voucher citation for each taxon documented.
... About 70 % of California is within the California floristic province, one of 36 global biodiversity hotspots sensu Myers 2000 and the only hotspot in North America (Myers et al., 2000). This province supports several different ecosystem types and exhibits a high degree of plant endemism (Burge et al., 2016). It is important, therefore, to assess the potential impact of air pollution within the region. ...
... California has a high degree of plant endemism. It is estimated that 42 % of vascular plant species native to the California Floristic Province (which covers most of California, though also extends a bit into surrounding states) are endemics (Burge et al., 2016), and stresses from ozone exposure are a likely conservation concern for rare plants. Recent studies have also found ozone exposures with high potential for negative ozone impacts on vegetation in California (Bytnerowicz et al., 2019;Yates et al., 2020). ...
Exposure to tropospheric ozone pollution impairs photosynthesis and growth in plants and this can have consequences for ecosystems. However, exposure-response research in the United States (U.S.) has historically focused on trees and crops, and less attention has been given to non-crop herbaceous species. We combined U.S. Environmental Protection Agency ozone monitoring data from the entirety of 2016 with published exposure-response relationships from controlled exposure experiments for twenty herbaceous plant species occurring in California. The U.S. Department of Agriculture PLANTS database was used to identify county-level occurrence data of these plant species. A kriged ozone exposure surface for 2016 was generated using data from monitoring stations in California and surrounding states, using Accumulated Ozone exposure over a Threshold of 40 ppb (AOT40) as an exposure metric. County-wide ozone exposure estimations were then combined with published exposure response functions for focal plants, and maps were created to estimate ozone-induced growth losses in the counties where the plants occur. Plant species had estimated annual growth losses from <1 % to >20 % based on exposure levels and sensitivity. Of the 20 species, 17 had predicted biomass loss >5 % in at least one county, emphasizing the vulnerability of herbaceous species at recent ozone concentrations. Butte, Nevada, Plumas, San Luis Obispo, and Shasta Counties, an area of about 31,652 km2, had the highest number of species (6) with >10 % estimated biomass loss, the loss threshold for European critical levels. White clover (Trifolium repens L.) was one of the most affected species with more than an estimated 10 % annual estimated growth loss over 59 % of the state. Overall, these estimated growth losses demonstrate potential for shifts in plant communities and negative effects on ecosystems. This study addresses critical policy needs for risk assessments on herbaceous species in a single year of ozone exposure.
... One particular form of semiarid vegetation, coastal sage scrub (CSS), is characteristic of the lowland and middle elevations of the coastal Pacific Mediterranean Climate Zone that encompasses the southern portions of California and northwest Baja California [8,9]. The CSS ecosystem is a biodiversity hotspot that supports high plant species richness and endemism [10,11], including at least 60 plants and thirty animal taxa considered rare [12]. ...
Increasing urbanization on the Baja California Peninsula threatens ant diversity. Reductions in ant species diminish ecosystem services provided to semiarid coastal scrub areas. Peri-urban areas in particular are at high risk of reductions in ant biodiversity due to development. To document and evaluate ant species diversity and richness in a rapidly developing area, nine sites were sampled within areas of coastal sage scrub (CSS) encircling the urban periphery of Ensenada, Baja California. Forty species and 17 genera of ants were collected, only one of which was non-native. Although the sampled area represents less than 1% of the peninsula and 3% of the State of Baja California, approximately one-third of the total species recorded for the peninsula and state were collected. Environmental variables (compass orientation, slope, and vegetation cover) were not significant determinants of species richness. Sandy soils were associated with the highest species abundance, richness, and functional diversity of feeding guilds. Despite limitations, our results present a historically significant snapshot of ant diversity in the sage scrub areas surrounding Ensenada. Sandy regions of semiarid coastal scrub are prime conservation management areas as they support the greatest functional diversity and have the highest potential to supply environmental services to the surrounding CSS ecosystem.
... Like other regions of the world (Bowman et al., 2020), California and the western United States generally have experienced their largest and most severe fires in the last 20 years (Li & Banerjee, 2021). With a wide range of ecosystems (Burge et al., 2016;Harrison, 2013), California presents an important opportunity to understand the impacts of megafire on diverse ecological communities and to observe how patterns of species vulnerability or resilience may interact with these perturbations. ...
Abstract Increasingly frequent megafires are dramatically altering landscapes and critical habitats around the world. Across the western United States, megafires have become an almost annual occurrence, but the implication of these fires for the conservation of native wildlife remains relatively unknown. Woodland savannas are among the world's most biodiverse ecosystems and provide important food and structural resources to a variety of wildlife, but they are threatened by megafires. Despite this, the great majority of fire impact studies have only been conducted in coniferous forests. Understanding the resistance and resilience of wildlife assemblages following these extreme perturbations can help inform future management interventions that limit biodiversity loss due to megafire. We assessed the resistance of a woodland savanna mammal community to the short‐term impacts of megafire using camera trap data collected before, during, and after the fire. Specifically, we utilized a 5‐year camera trap data set (2016–2020) from the Hopland Research and Extension Center to examine the impacts of the 2018 Mendocino Complex Fire, California's largest recorded wildfire at the time, on the distributions of eight observed mammal species. We used a multispecies occupancy model to quantify the effects of megafire on species' space use, to assess the impact on species size and diet groups, and to create robust estimates of fire's impacts on species diversity across space and time. Megafire had a negative effect on the detection of certain mammal species, but overall, most species showed high resistance to the disturbance and returned to detection and site use levels comparable to unburned sites by the end of the study period. Following megafire, species richness was higher in burned areas that retained higher canopy cover relative to unburned and burned sites with low canopy cover. Fire management that prevents large‐scale canopy loss is critical to providing refugia for vulnerable species immediately following fire in oak woodlands, and likely other mixed‐forest landscapes.
... 7, 9, and 26) and the evolutionary origins of CFP biodiversity (8,22,27) and community assembly dynamics (7,9). The CFP hot spot is characterized largely by a Mediterranean climate and includes a range of biotic subregions that together support nearly 7,000 native species or subspecies of plants (28). Vegetation types within the CFP are a mosaic of ecosystems ranging from serpentine chaparral to coniferous forests and exhibit high spatial variation distributed across a topographically diverse landscape (26). ...
Biogeographic history can set initial conditions for vegetation community assemblages that determine their climate responses at broad extents that land surface models attempt to forecast. Numerous studies have indicated that evolutionarily conserved biochemical, structural, and other functional attributes of plant species are captured in visible-to-short wavelength infrared, 400 to 2,500 nm, reflectance properties of vegetation. Here, we present a remotely sensed phylogenetic clustering and an evolutionary framework to accommodate spectra, distributions, and traits. Spectral properties evolutionarily conserved in plants provide the opportunity to spatially aggregate species into lineages (interpreted as “lineage functional types” or LFT) with improved classification accuracy. In this study, we use Airborne Visible/Infrared Imaging Spectrometer data from the 2013 Hyperspectral Infrared Imager campaign over the southern Sierra Nevada, California flight box, to investigate the potential for incorporating evolutionary thinking into landcover classification. We link the airborne hyperspectral data with vegetation plot data from 1372 surveys and a phylogeny representing 1,572 species. Despite temporal and spatial differences in our training data, we classified plant lineages with moderate reliability (Kappa = 0.76) and overall classification accuracy of 80.9%. We present an assessment of classification error and detail study limitations to facilitate future LFT development. This work demonstrates that lineage-based methods may be a promising way to leverage the new-generation high-resolution and high return-interval hyperspectral data planned for the forthcoming satellite missions with sparsely sampled existing ground-based ecological data.
Wildfires are increasingly altering ecosystems, posing significant challenges for biodiversity conservation and ecosystem management. In this study, we used DNA metabarcoding to assess the response of arthropod communities to large-scale wildfires across diverse habitat types. We sampled six reserves within the University of California Natural Reserve System (UCNRS), each which was partially burned in the 2020 Lightning Complex wildfires in California. Using yellow pan traps to target pollinators, we collected arthropods from burned and unburned sites across multiple habitat types including oak woodland, redwood, scrub, chamise, grassland, forest, and serpentine habitats. We found no significant difference in alpha diversity values between burned and unburned sites; instead, seasonal variations played a significant role in arthropod community dynamics, with the emergence of plant species in Spring promoting increased pollinator richness at all sites. Compositional similarity analysis revealed that burn status was not a significant grouping factor when comparing all sites. Instead, community composition primarily varied across reserves, indicating distinct pools of arthropods structured geographically. Habitat type played a crucial role in determining the response of arthropod communities to fire. While communities in grasslands and oak woodlands exhibited recovery following burn, scrublands experienced substantial changes in community composition. Our study highlights the importance of examining community responses to wildfires across broad spatial scales and diverse habitat types. By understanding the nuanced dynamics of arthropod communities in response to fire disturbances, we can develop effective conservation strategies that promote resilience and maintain biodiversity in the face of increasing wildfire frequency and intensity driven by climate change.
Wildfires are increasingly altering ecosystems, posing significant challenges for biodiversity conservation and ecosystem management. In this study, we used DNA metabarcoding to assess the response of arthropod communities to large-scale wildfires across diverse habitat types. We sampled six reserves within the University of California Natural Reserve System (UCNRS), each which was partially burned in the 2020 Lightning Complex wildfires in California. Using yellow pan traps to target pollinators, we collected arthropods from burned and unburned sites across multiple habitat types including oak woodland, redwood, scrub, chamise, grassland, forest, and serpentine habitats. We found no significant difference in alpha diversity values between burned and unburned sites; instead, seasonal variations played a significant role in arthropod community dynamics, with the emergence of plant species in Spring promoting increased pollinator richness at all sites. Compositional similarity analysis revealed that burn status was not a significant grouping factor when comparing all sites. Instead, community composition primarily varied across reserves, indicating distinct pools of arthropods structured geographically. Habitat type played a crucial role in determining the response of arthropod communities to fire. While communities in grasslands and oak woodlands exhibited recovery following burn, scrublands experienced substantial changes in community composition. Our study highlights the importance of examining community responses to wildfires across broad spatial scales and diverse habitat types. By understanding the nuanced dynamics of arthropod communities in response to fire disturbances, we can develop effective conservation strategies that promote resilience and maintain biodiversity in the face of increasing wildfire frequency and intensity driven by climate change.
A new species of the Plectreurys castanea species group from Los Angeles County, California, United States, is described, diagnosed, and illustrated. Males of P. palacioscardieli sp. nov. are characterized by the shape of the apical division of the bulb. A brief discussion of the restricted distribution and resemblance to other species of the same group is given.
Dudleya brittonii Johans. sensu lato (Crassulaceae) es una planta en roseta de gran tamaño endémica de la costa noroeste de Baja California, México que históricamente ha incluido las formas glauca y verde. En este estudio determinamos que las formas verdes son distintas a D. brittonii y exhiben una variabilidad morfológica que justifican su reconocimiento taxonómico a nivel específico y subespecífico. Reconocemos y describimos tres nuevos taxa, D. josedelgadilloi Mulroy, Guilliams, & Hasenstab sp. nov., D. reidmoranii Mulroy, Guilliams, & Hasenstab sp. nov. subsp. reidmoranii, y D. reidmoranii subsp. cascada Mulroy, Guilliams, & Hasenstab subsp. nov., basados en numerosas mediciones de especímenes frescos en campo que fueron analizadas con morfometría cuantitativa y estadística multivariada. Estas entidades han sido consideradas por mucho tiempo como parte de D. brittonii, sin embargo no fueron incluidas en la descripción original (Johansen 1933). Demostramos también un evento de desplazamiento de caracteres (divergencia en simpatría) relacionado con un desfase en los tiempos de floración entre D. brittonii (glauca) y D. reidmoranii subsp. reidmoranii (verde). Poblaciones de D. reidmoranii subsp. reidmoranii que co-ocurren con D. brittonii muestran un retraso de 6 semanas a tres meses en el promedio de inicio y término de floración con respecto a poblaciones de D. reidmoranii subsp. reidmoranii cercanas que no co-ocurren con D. brittonii. Este desfase en los tiempos de floración podría representar un mecanismo de aislamiento precigótico importante entre estas plantas que de otra manera son altamente interfértiles. Un estudio preliminar de cultivo de D. reidmoranii subsp. reidmoranii (verde) creciendo en presencia y ausencia de D. brittonii (glauca) mostró el mismo patrón en los tiempos de floración observado en el campo, lo que sugiere que este patrón tiene una base genética. El desfase temporal en D. reidmoranii subsp. reidmoranii y subsp. cascada resulta en una floración durante el verano en estos taxa, mientras que D. josedelgadilloi y D. brittonii tienen su floración en primavera, lo cual podría atraer a un diferentes tipos de de polinizadores principales (e.g., colibríes vs. insectos). Describimos adaptaciones a polinización por colibríes, como infloresecencias y flores pendientes, asociadas a la floración durante el verano en las dos subespecies de D. reidmoranii, en contraste con adaptaciones que favorecen polinización por insectos durante la primavera en D. brittonii y D. josedelgadilloi. El reconocimiento de estas novedades taxonómicas en una región relativamente bien documentada confirma la extraordinaria diversidad y alto endemismo de la flora asociada al clima Mediterráneo del noroeste de Baja California. La velocidad de la expansión de las actividades humanas en la región resalta la urgencia de aumentar la exploración botánica y continuar la implementación de medidas de conservación antes de que la pérdida de biodiversidad sea mayor.
Based on data of bryophyte invasions into 82 regions on five continents of both hemispheres, we aim here at a first comprehensive overview of the impacts that bryophytes may have on biodiversity and socio-economy. Of the 139 bryophytes species which are alien in the study regions seven cause negative impacts on biodiversity in 26 regions, whereas three species cause negative impacts on socio-economic sectors in five regions. The vast majority of impacts stem from anecdotal observations, whereas only 14 field or experimental studies (mostly on Campylopus introflexus in Europe) have quantitatively assessed the impacts of an alien bryophyte. The main documented type of impact on biodiversity is competition (8 alien bryophytes), with native cryptogams being most affected. In particular, C. introflexus (9 regions) and Pseudoscleropodium purum (7 regions) affect resident species composition. The few socio-economic impacts are caused by alien bryophytes which form dense mats in lawns and are then considered a nuisance. Most negative impacts on biodiversity have been recorded in natural grasslands, forests, and wetlands. Impacts of alien bryophytes on biodiversity and socio-economy are a recent phenomenon, with >85 % of impacts on biodiversity, and 80 % of impacts on socio-economy recorded since 1990. On average, 40 years (impacts on biodiversity) and 25 years (impacts on socio-economy) elapsed between the year a bryophyte species has been first recorded as alien in a region and the year impacts have been recorded first. Taking into account the substantial time lag between first record and first recorded impact in a region, it seems to be likely that the currently moderate impacts of alien bryophytes will continue to increase. As quantitative studies on impacts of alien bryophytes are rare and restricted to few environments and biogeographic regions, there is a need for addressing potential impacts of alien bryophytes in yet understudied settings.
The California Floristic Province exhibits one of the richest floras on the planet, with more than 5500 native plant species, approximately 40% of which are endemic. Despite its impressive diversity and the attention it has garnered from ecologists and evolutionary biologists, historical causes of species richness and endemism in California remain poorly understood. Using a phylogenetic analysis of 16 angiosperm clades, each containing California natives in addition to species found only outside California, we show that CA's current biodiversity primarily results from low extinction rates, as opposed to elevated speciation or immigration rates. Speciation rates in California were lowest among Arcto-Tertiary lineages (i.e., those colonizing California from the north, during the Tertiary), but extinction rates were universally low across California native plants of all historical, geographic origins. In contrast to long-accepted ideas, we find that California diversification rates were generally unaffected by the onset of the Mediterranean climate. However, the Mediterranean climate coincided with immigration of many desert species, validating one previous hypothesis regarding origins of CA's plant diversity. This study implicates topographic complexity and climatic buffering as key, long-standing features of CA's landscape favoring plant species persistence and diversification, and highlights California as an important refuge under changing climates.
Aim Biogeographical regionalizations, such as zoogeographical regions, floristic kingdoms or ecoregions, represent categorizations central to many basic and applied questions in biogeography, ecology, evolution and conservation. Traditionally established by experts based on qualitative evidence, the lack of transparency and quantitative support has set constraints on their utility. The recent availability of global species range maps, novel multivariate techniques and enhanced computational power now enable a quantitative scrutiny and extension of biogeographical regionalizations that will facilitate new and more rigorous uses. In this paper we develop and illustrate a methodological roadmap for species-level biogeographical regionalizations at the global scale and apply it to mammals.
Identification of global biodiversity hotspots is a leading conservationpriority ( Hotspots.Conservation International, Washington, DC; Precious Heritage: The Statusof Biodiversity in the United States. Oxford University Press, Oxford, UK), but weknow little about the nature and structure of such hotspots. Botanical richnessin one recently identified hotspot, the California Floristic Province, has longbeen attributed by evolutionists to edaphic and climatic heterogeneity. Here we demonstrate that the flora restricted (endemic) toserpentine soil, the state's most botanically distinctive substrate, showsunusually high ' diversity' – i.e., spatial variation inspecies composition – among regions, although ''diversity within any given region is low. Conservation of an endemic-rich florarequires a network of sites to capture this among-region or spatial component ofdiversity.
Rieseberg, L. H. & Brouillet, L.: Are many plant species paraphyletic? – Taxon 43: 21‐32. 1994. – ISSN 0040‐0262.
The phylogenetic Status of plant species has become a critical issue in systematic and evolutionary botany, due in part to the influence of Hennigian principles on organismal classification. This paper reviews various modes of speciation and their frequency in plants, and discusses predicted phylogenetic consequences of different modes of speciation. The classic model of allopatric speciation by subdivision will typically generate monophyletic daughter species, whereas most geographically local models of speciation (e.g., the founder effect model), will produce a paraphyletic progenitor and monophyletic derivative species. Due to the theoretical difficulty of transforming widespread population systems through gene flow or selection, allopatric speciation by subdivision is likely to be less frequent than geographically local models of speciation. Low levels of gene flow will also increase the time required for the progenitor species to achieve monophyly. Thus, many plant species are likely to be paraphyletic, and predictably a species classification based on the criterion of monophyly is unlikely to be an effective tool for describing and ordering biological diversity.
We asked whether evolutionary transitions to serpentine endemism are associated with transitions to more favorable environments. Theory and observation suggest that benign (e.g., high rainfall and less extreme temperatures) climates should favor the evolution of habitat specialism, both because such climates may facilitate persistence of small populations with novel adaptations, and because competition with non-specialists may be stronger in benign climates. Non-climatic factors, such as habitat availability, should also be associated with transitions to habitat specialism. We examined phylogenetic transitions to serpentine endemism in 23 Californian plant taxa. We contrasted transitions from serpentine-intolerant ancestors, where speciation entails novel adaptations to serpentine, with transitions from serpentine-tolerant ancestors, where the formation of a new serpentine-endemic taxon may result from an altered competitive environment. We found that transitions to endemism were strongly associated with transitions to regions with more benign climates, but only in the case of endemics arising from intolerant ancestors. In contrast, transitions to endemism from both types of ancestor were associated with transitions to regions with greater habitat availability. These results are consistent with the expectation that benign climates promote the persistence of small populations with novel adaptations both before and after speciation.
Abstract This paper addresses some of the conceptual issues involved in the analysis of the age and origin of mediterranean-climate plant taxa, paying particular attention to three topics: (1) the importance of an explicit time frame in the definition of biogeographical origins, (2) the distinction between the age of traits and the age of taxa, and (3) the idea of mediterranean-type ecosystems as environmental islands. (1) In California, recent analyses demonstrate that the diversity of species derived from different biogeographical origins is significantly correlated with temperature and precipitation gradients. These patterns support the hypothesis that niche conservatism is an important factor structuring modern diversity gradients. However, depending on how far back in time one looks, a species may be assigned to different origins; future discussions of biogeographical origins need to address the appropriate time frame for analysis. (2) Past research has demonstrated distinctive trait syndromes among woody plants of the Mediterranean, Chile, California and Mexico, and proposed that the syndromes are associated with lineages of different age in these floras. Reanalysis of individual traits demonstrates greater variability among regions than previously reported. The classification of plants into ‘old’ and ‘new’ genera is re-evaluated, and it is suggested that greater attention be paid to the age of traits, rather than to the age of taxa, especially at an arbitrary rank such as genus. (3) The idea of mediterranean-climate regions as ‘climatic islands’ is examined. Space–time diagrams of climate enable one to view the emergence of distinctive climatic regions in a continental context. The terms ‘synclimatic’ and ‘anticlimatic’ are proposed, referring to migration routes that parallel climate contours in space and time versus those that cross contours (including the case of geographic stasis in the face of climate change), respectively. Mediterranean-climate regions have served as important case studies in plant ecology and evolution, and merit continued close examination in the light of continued advances in phylogenetics and palaeoecology.
Question: Can we recognize areas of high endemism and high endemic richness, using data from collections, and what are the ecological variables that best explain these areas?
Location: Peninsula of Baja California, Mexico.
Methods: We analysed the distribution of 723 endemic vascular plants species along the peninsula of Baja California and neighbouring islands distributed in 218 cartographic cells 15’ x 20’ in size. By means of a residual analysis, we identified areas of significantly high endemic species richness, and we calculated the degree of endemicity (or rarity) in each cell by giving to each species a weight factor inversely proportional to the land area it covers.
Results: Nine regions of high-endemicity and/or high endemic species richness were found.
Discussion and conclusions: The analyses of rarity and endemic species richness showed two contrasting scenarios: High endemicity values in oceanic and sky islands accounts for a high number of species with a restricted distribution, promoted most likely by genetic isolation and high environmental heterogeneity. High endemic richness along the peninsular coast is related to ecotonal transition along vegetation types. After correcting for collection effort (i.e. the number of specimens collected within a cell), we found the phytogeographic region and altitudinal heterogeneity to be the variables that best predicted endemic richness. Both high endemism and high endemic richness have distinct geographic patterns within our study region. The nine endemic regions provide elements for priority definitions in future conservation programs.