Rarity and extinction risk in coral reef angelfishes on isolated islands: interrelationships among abundance, geographic range size and specialisation

Determining the species most vulnerable to increasing degradation of coral reef habitats requires identification of the ecological traits that increase extinction risk. In the terrestrial environment, endemic species often face a high risk of extinction because of an association among three traits that threaten species persistence: small geographic range size, low abundance and ecological specialisation. To test whether these traits are associated in coral reef fishes, this study compared abundance and specialisation in endemic and widespread angelfishes at the remote Christmas and Cocos Islands in the Indian Ocean. The interrelationships among traits conferring high extinction risk in terrestrial communities did not apply to these fishes. Endemic angelfishes were 50–80 times more abundant than widespread species at these islands. Furthermore, there was no relationship between abundance and ecological specialisation. Endemic species were not more specialised than widespread congeners and endemics used similar resources to many widespread species. Three widespread species exhibited low abundance and some degree of specialisation, which may expose them to a greater risk of local extinction. For endemic species, high abundance and lack of specialisation on susceptible habitats may compensate for the global extinction risk posed by having extremely small geographic ranges. However, recent extinctions of small range reef fishes confirm that endemics are not immune to the increasing severity of large-scale disturbances that can affect species throughout their geographic range.     

Population genomic response to geographic gradients by widespread and endemic fishes of the Arabian Peninsula

Genetic structure within marine species may be driven by local adaptation to their environment, or alternatively by historical processes, such as geographic isolation. The gulfs and seas bordering the Arabian Peninsula offer an ideal setting to examine connectivity patterns in coral reef fishes with respect to environmental gradients and vicariance. The Red Sea is characterized by a unique marine fauna, historical periods of desiccation and isolation, as well as environmental gradients in salinity, temperature, and primary productivity that vary both by latitude and by season. The adjacent Arabian Sea is characterized by a sharper environmental gradient, ranging from extensive coral cover and warm temperatures in the southwest, to sparse coral cover, cooler temperatures, and seasonal upwelling in the northeast. Reef fish, however, are not confined to these seas, with some Red Sea fishes extending varying distances into the northern Arabian Sea, while their pelagic larvae are presumably capable of much greater dispersal. These species must therefore cope with a diversity of conditions that invoke the possibility of steep clines in natural selection. Here, we test for genetic structure in two widespread reef fish species (a butterflyfish and surgeonfish) and eight range‐restricted butterflyfishes across the Red Sea and Arabian Sea using genome‐wide single nucleotide polymorphisms. We performed multiple matrix regression with randomization analyses on genetic distances for all species, as well as reconstructed scenarios for population subdivision in the species with signatures of isolation. We found that (a) widespread species displayed more genetic subdivision than regional endemics and (b) this genetic structure was not correlated with contemporary environmental parameters but instead may reflect historical events. We propose that the endemic species may be adapted to a diversity of local conditions, but the widespread species are instead subject to ecological filtering where different combinations of genotypes persist under divergent ecological regimes.     

Larval supply is a good predictor of recruitment in endemic but not non-endemic fish populations at a high latitude coral reef

Despite extensive research, factors influencing the importance of pre- and post-settlement processes to recruitment variability remain ambiguous. Using a novel perspective, we investigated the potential influence of endemism on the relationship between larval supply and recruitment in reef fish populations at Lord Howe Island, Australia. Larval supply and recruitment were measured for three regional endemic and four widespread non-endemic species using light traps, artificial collectors, and underwater visual censuses. Recruitment was correlated with larval supply in endemics but not in non-endemics, likely due to a combination of low larval supply and post-settlement survival of non-endemics. Surveys also indicated that endemics were far more abundant and occurred in more locations than closely related non-endemics. These preliminary findings suggest that either local adaptation enhances recruitment in endemics through higher larval replenishment rates or reduced post-settlement mortality, populations of widespread species at the periphery of their range are poorly adapted to local environmental conditions and therefore experience lower and more variable settlement and post-settlement survival rates, or both.     

Biodiversity hotspots, centres of endemicity, and the conservation of coral reefs

On land, biodiversity hotspots typically arise from concentrations of small‐range endemics. For Indo‐Pacific corals and reef fishes, however, centres of high species richness and centres of high endemicity are not concordant. Moreover ranges are not, on average, smaller inside the Central Indo‐Pacific (CI‐P) biodiversity hotspot. The disparity between richness and endemicity arises because corals and reef fishes have strongly skewed range distributions, with many species being very widespread. Consequently, the largest ranges overlap to generate peaks in species richness near the equator and the CI‐P biodiversity hotspot, with only minor contributions from endemics. Furthermore, we find no relationship between the number of coral vs. fish endemics at locations throughout the Indo‐Pacific, even though total richness of the two groups is strongly correlated. The spatial separation of centres of endemicity and biodiversity hotspots in these taxa calls for a two‐pronged management strategy to address conservation needs.     

Plant genetic diversity in the Canary Islands: a conservation perspective

The Canary Islands are an Atlantic volcanic archipelago with a rich flora of ～570 endemic species. The endemics represent ～40% of the native flora of the islands, and ～20% of the endemics are in the E (endangered) category of the International Union for Conservation of Nature. A review of allozyme variation in 69 endemic species belonging to 18 genera and eight families is presented. The average species-level genetic diversity (H(T)) at allozyme loci is 0.186, which is twice as high as the mean reported for endemics of Pacific archipelagos. Possible factors contributing to this higher diversity are discussed, but the reasons remain obscure. An average of 28% of the allozyme diversity within species resides among populations, indicating a high level of interpopulational differentiation. Studies of reproductive biology indicate that many of the endemic species are outcrossers. The high total diversity within species, the relatively high differentiation among populations, and the outcrossing breeding systems have implications for species conservation. Decreased population sizes in outcrossing species would promote biparental inbreeding and increase inbreeding depression. The relatively high proportion of allozyme diversity among populations indicates that the most effective strategy for preserving genetic variation in species is to conserve as many populations as possible. The genetic diversity in many Canary Island endemics is endangered by: (1) overgrazing by introduced animals, such as barbary sheep, goats, mouflons, rabbits, and sheep; (2) interspecific hybridization following habitat disturbance or planting of endemics along roadsides or in public gardens; (3) competition with alien plant species; and (4) decline of population size because of urban development and farming.     

Population genetics of threatened wild plants in Japan

Approximately one-fourth of Japan's native plant species are threatened with extinction. To conserve these species, it is critical to evaluate genetic diversity at species-level and population-level. Some factors, including population size and geographic distribution, are known to influence the population genetic diversity of wild plant species. This article briefly reviews the population genetic studies that have been conducted on wild threatened plants in Japan. A large population size or wide geographic distribution does not always lead to large genetic diversity, suggesting that historical factors such as speciation processes and population expansion often play more important roles in determining genetic diversity than the number of remnant individuals. The mating system of a species also affects genetic diversity; predominantly selfing species tend to have smaller genetic diversity than outcrossing congeners. Another issue of concern in the conservation genetics of wild plants in Japan is the genetic diversity of insular endemics, because Japan consists of many islands, and the insular flora contains many endemic and threatened species. Previous studies on endemic plants on the Bonin and the Ryukyu Islands are reviewed. Compared to the cases of the Bonin Islands or other oceanic islands, there is much larger genetic diversity in plants endemic to the Ryukyu Islands. This difference is probably the result of the differences in the geological history of these islands. Electronic Publication     

Phylogeny and historical demography of endemic fishes in Lake Biwa: the ancient lake as a promoter of evolution and diversification of freshwater fishes in western Japan

To elucidate the origins of the endemic fish of Lake Biwa, an ancient lake in Japan, and the role of the lake in the diversification of freshwater fish in western Japan, we established a molecular phylogenetic framework with an absolute time scale and inferred the historical demography of a large set of fish species in and around the lake. We used mtDNA sequences obtained from a total of 190 specimens, including 11 endemic species of Lake Biwa and their related species, for phylogenetic analyses with divergence time estimations and from a total of 2319 specimens of 42 species (including 14 endemics) occurring in the lake for population genetic analyses. Phylogenetic analysis suggested that some of the endemic species diverged from their closest relatives earlier (1.3–13.0 Ma) than the period in which the present environmental characteristics of the lake started to develop (ca. 0.4 Ma), whereas others diverged more recently (after 0.4 Ma). In contrast, historical demographic parameters suggested that almost all species, including endemic and nonendemic ones, expanded their populations after the development of the present lake environment. In phylogeographic analyses, common or very close haplotypes of some species were obtained from Lake Biwa and other regions of western Japan. The phylogenetic and historical demographic evidence suggests that there was a time lag between phylogenetic divergence and population establishment and that phenotypic adaptation of some endemic species to the limnetic environment occurred much later than the divergences of those endemic lineages. Population structure and phylogeographic patterns suggest that Lake Biwa has functioned not only as the center of adaptive evolution but also as a reservoir for fish diversity in western Japan.     

Biogeography and the structure of coral reef fish communities on isolated islands

Aim To determine the applicability of biogeographical and ecological theory to marine species at two remote island locations. This study examines how biogeography, isolation and species geographic range size influence patterns of species richness, endemism, species composition and the abundance of coral reef fishes. Location Christmas Island and the Cocos (Keeling) Islands in the tropical eastern Indian Ocean. Methods Published species lists and underwater visual surveys were used to determine species richness, endemism, species composition and abundance of reef fishes at the islands. These data were statistically compared with patterns of species composition and abundance from the neighbouring ‘mainland’ Indonesian region. Results The two isolated reef fish communities were species‐poor and contained a distinct taxonomic composition with an overrepresentation of species with high dispersal potential. Despite low species richness, we found no evidence of density compensation, with population densities on the islands similar to those of species‐rich mainland assemblages. The mix of Indian and Pacific Ocean species and the proportional representations of the various regional faunas in the assemblages were not influenced by the relative proximity of the islands to different biogeographical provinces. Moreover, species at the edge of their range did not have a lower abundance than species at the centre of their range, and endemic species had substantially higher abundances than widespread species. At both locations, endemism was low (less than 1.2% of the community); this may be because the locations are not sufficiently isolated or old enough to promote the evolution of endemic species. Main conclusions The patterns observed generally conform to terrestrial biogeographical theory, suggesting that similar processes may be influencing species richness and community composition in reef fish communities at these remote islands. However, species abundances differed from typical terrestrial patterns, and this may be because of the life history of reef fishes and the processes maintaining isolated populations.     

Reef fish hybridization: lessons learnt from butterflyfishes (genus Chaetodon)

Natural hybridization is widespread among coral reef fishes. However, the ecological promoters and evolutionary consequences of reef fish hybridization have not been thoroughly evaluated. Butterflyfishes form a high number of hybrids and represent an appropriate group to investigate hybridization in reef fishes. This study provides a rare test of terrestrially derived hybridization theory in the marine environment by examining hybridization between Chaetodon trifasciatus and C. lunulatus at Christmas Island. Overlapping spatial and dietary ecologies enable heterospecific encounters. Nonassortative mating and local rarity of both parent species appear to permit heterospecific breeding pair formation. Microsatellite loci and mtDNA confirmed the status of hybrids, which displayed the lowest genetic diversity in the sample and used a reduced suite of resources, suggesting decreased adaptability. Maternal contribution to hybridization was unidirectional, and no introgression was detected, suggesting limited, localized evolutionary consequences of hybridization.Comparisons to other reef fish hybridization studies revealed that different evolutionary consequences emerge, despite being promoted by similar factors, possibly due to the magnitude of genetic distance between hybridizing species. This study highlights the need for further enquiry aimed at evaluating the importance and long-term consequences of reef fish hybridization.     

Habitat specialization in tropical continental shelf demersal fish assemblages

The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth), down the fore reef slope to the reef base (10-30 m depth) then across the adjacent continental shelf (30-110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats through which fish can migrate.     

Population structure in the catfish Trichogenes longipinnis: drift offset by asymmetrical migration in a tiny geographic range

Based on population genetic theory and empirical studies of small populations, we expect that species with very small ranges (narrow endemics) will exhibit reduced genetic diversity, increasing their susceptibility to the negative effects of genetic homogeneity. Although this pattern of reduced diversity applies to most narrow endemics, conservation biologists have yet to identify a general pattern for the degree of spatial population genetic structure expected in species with very small ranges. In part, this is because the degree of population structure within narrow endemics will be highly variable depending on the equilibrium between the homogenizing effects of dispersal and the diversifying effects of drift and local selection in small populations, thus precluding general predictions about the relative importance of small range, small population sizes, and habitat patchiness for maintaining genetic diversity in narrowly-distributed species. We document a striking example of high population structure in the tiny geographic range of a stream-dwelling catfish, Trichogenes longipinnis , endemic to the Atlantic Forest of Brazil. The maintenance of this diversity results from a combination of asymmetrical and limited dispersal, and drift in small populations. Our results highlight the need to understand population structure, and not only overall genetic diversity, of narrowly-distributed species for their conservation planning.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 259–274.     

Shifts in Species Interactions Due to the Evolution of Functional Differences between Endemics and Non-Endemics: An Endemic Syndrome Hypothesis

Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic), here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change.     

Allozyme diversity within and divergence among species ofTolpis(Asteraceae-Lactuceae) in the Canary Islands: systematic, evolutionary, and biogeographical implications

Plants endemic to oceanic islands represent some of the most unusual and rare taxa in the world. Enzyme electrophoresis was used to assess genetic diversity within and divergence among all endemic species of a small genus of plants on the Canary Islands. Our results show that the genus Tolpis is similar to many other island groups in having generally low allozyme divergence among species, with the highest divergence found among four groups of endemics. The two rare and highly localized species T. glabrescens and T. crassiuscula are each divergent from all other species in the Canaries. Tolpis coronopifolia is also divergent at allozyme loci; this is the only endemic species that is a self-compatible annual (or weak biennial). A large, morphologically variable species complex consisting of T. laciniata and T. lagopoda together with several named and unnamed morphological variants shows low allozyme divergence among its elements. The evolution of polyploidy from diploid ancestors in situ in oceanic archipelagos is uncommon, but the tetraploid T. glabrescens is an exception. Allozyme data do not implicate any extant diploid Tolpis species as parents of the polyploid. It is possible that T. glabrescens originated early in the evolution of Tolpis in the Canary Islands and that its parents are now extinct. The nonendemic T. barbata shows no greater divergence from the Canary Island endemics than some endemics exhibit among themselves. Both changes in allele frequencies and unique alleles are responsible for genetic divergence among species of Tolpis.     

Phylogenetic perspectives on reef fish functional traits

Functional traits have been fundamental to the evolution and diversification of entire fish lineages on coral reefs. Yet their relationship with the processes promoting speciation, extinction and the filtering of local species pools remains unclear. We review the current literature exploring the evolution of diet, body size, water column use and geographic range size in reef‐associated fishes. Using published and new data, we mapped functional traits on to published phylogenetic trees to uncover evolutionary patterns that have led to the current functional diversity of fishes on coral reefs. When examining reconstructed patterns for diet and feeding mode, we found examples of independent transitions to planktivory across different reef fish families. Such transitions and associated morphological alterations may represent cases in which ecological opportunity for the exploitation of different resources drives speciation and adaptation. In terms of body size, reconstructions showed that both large and small sizes appear multiple times within clades of mid‐sized fishes and that extreme body sizes have arisen mostly in the last 10 million years (Myr). The reconstruction of range size revealed many cases of disparate range sizes among sister species. Such range size disparity highlights potential vicariant processes through isolation in peripheral locations. When accounting for peripheral speciation processes in sister pairs, we found a significant relationship between labrid range size and lineage age. The diversity and evolution of traits within lineages is influenced by trait–environment interactions as well as by species and trait–trait interactions, where the presence of a given trait may trigger the development of related traits or behaviours. Our effort to assess the evolution of functional diversity across reef fish clades adds to the burgeoning research focusing on the evolutionary and ecological roles of functional traits. We argue that the combination of a phylogenetic and a functional approach will improve the understanding of the mechanisms of species assembly in extraordinarily rich coral reef communities.     

When endemic coral‐reef fish species serve as models: endemic mimicry patterns in the Marquesas Islands

This article documents several cases of widespread species, which usually mimic other widespread species throughout the Indo‐Pacific, using endemic Marquesan species as a model and displaying endemic mimicry patterns. This discovery adds a new line of evidence to the uniqueness of the Marquesas Islands, which not only host a high number of endemic reef‐fish species, but also endemic mimicry patterns.     

Allozyme diversity in endemic flowering plant species of the Juan Fernandez Archipelago, Chile: ecological and historical factors with implications for conservation

The level and apportionment of allozyme diversity were determined for 29 endemic (and 1 native) species from the Juan Fernández Islands, Chile. Mean diversities at the species level (H(es) = 0.065) are low but comparable to those measured for other insular endemics in the Pacific. A high mean proportion (0.338) of species-level diversity resides among populations. Diversity statistics were compared for species in different ecological-life history trait categories and abundance classes. Species occurring in large populations and those present in scattered small populations have higher diversities than species occurring in one or two populations. Although not significant with the conservative statistical test employed, lower diversity was found in highly selfing species as compared to animal- or wind-pollinated species. The apportionment of genetic diversity within and among populations (G(ST) values) is not significantly different for any of the species categories. Of particular interest is the lack of difference between animal- and wind-pollinated species because previous analyses of large data sets showed higher differentiation between populations of animal- than wind-pollinated species. Historical factors, both ecological and phylogenetic in nature, can influence the level and apportionment of diversity within insular endemics, and thus ecological correlates of diversity seen in many continental species may not apply to endemics. The results have several conservation implications. The preservation of large populations or several small populations is important for conserving diversity within species because when species are reduced to one or two populations, allozyme diversity is sharply reduced. High mean G(ST) values for the species examined illustrate the need for conserving as many populations as possible, either in the wild or in the garden, to preserve maximal diversity within species. Effective conservation strategies require empirical knowledge of each species.     

Pleistocene refugium endemics exhibit greater allozymic diversity than widespread congeners in the genus Polygonella (Polygonaceae)

Populations of each of the 11 species of the North American angiosperm genus Polygonella (Polygonaceae) were sampled for electrophoretically detectable allozyme diversity. In contrast to expectations based on similar surveys in many other vascular plant groups, the two most widespread species of Polygonella showed reduced within-population gene diversity with respect to their narrowly endemic congeners. One possible explanation is that high levels of selfing in the widespread species have led to reduced population-level diversity. An alternative explanation is that large-scale migration during Pleistocene glaciations removed much of the diversity of these more northerly distributed species, while the endemics, several of which inhabit known Pleistocene refugia, were able to maintain higher levels of diversity because of population stability during the glacial cycles. If the latter explanation is correct, an important implication for conservation is that, for many genera in eastern North America, the species richest in gene diversity may be those most in danger of extirpation in the next decade, namely those species endemic to Pleistocene refugia such as the Lake Wales Ridge.     

Rare plants are common where you find them

Broad patterns in distribution and abundance can elucidate processes of evolution. A positive association between local abundance and the size of the geographic range has been demonstrated for closely related species across many taxa. This pattern is usually explained by assuming that species with smaller ranges are ecologically inferior (e.g., poor competitors or dispersers). Many areas of high endemism support local species that have evolved recently. The distribution of these neoendemics may reflect historical processes not accounted for by ecological, equilibrium hypotheses. We asked whether such traditional macroecological hypotheses also applied to the local abundance of seven narrowly endemic species and ecologically similar widespread congeners in the northern Rocky Mountains. For each of the 14 species, we estimated abundance of five randomly chosen populations by counting plants in 10 randomly located plots. The association between range size and local abundance was not positive. Instead, all seven narrow endemics were more abundant than their widespread congeners. Ecological specialization or differences in dispersal ability are not likely explanations for our results. We believe the local abundance of narrowly endemic species may be a sign of recent speciation. Most or all of our narrowly distributed species have probably not yet had time to spread to their full potential. Furthermore, theory predicts that speciation is more likely to occur in locally abundant populations. Our results suggest that strictly ecological mechanisms cannot explain abundance and distribution in regions with high neoendemism.     

Inferring the biogeographic origins of inter‐continental disjunct endemics using a Bayes‐DIVA approach

The arcto‐Tertiary relictual flora is comprised of many genera that occur non‐contiguously in the temperate zones of eastern Asia, Europe, eastern North America, and western North America. Within each distributional area, species are typically endemic and may thus be widely separated from closely related species within the other areas. It is widely accepted that this common pattern of distribution resulted from of the fragmentation of a once more‐continuous arcto‐Tertiary forest. The historical biogeographic events leading to the present‐day disjunction have often been investigated using a phylogenetic approach. Limitations to these previous studies have included phylogenetic uncertainty and uncertainty in ancestral range reconstructions. However, the recently described Bayes‐DIVA method handles both types of uncertainty. Thus, we used Bayes‐DIVA analysis to reconstruct the stem lineage distributions for 185 endemic lineages from 23 disjunct genera representing 17 vascular plant families. In particular, we asked whether endemic lineages within each of the four distributional areas more often evolved from (1) widespread ancestors, (2) ancestors dispersed from other areas, or (3) endemic ancestors. We also considered which of these three biogeographic mechanisms may best explain the origins of arcto‐Tertiary disjunct endemics in the neotropics. Our results show that eastern Asian endemics more often evolved from endemic ancestors compared to endemics in Europe and eastern and western North America. Present‐day endemic lineages in the latter areas more often arose from widespread ancestors. Our results also provide anecdotal evidence for the importance of dispersal in the biogeographic origins of arcto‐Tertiary species endemic in the neotropics.     

Adaptive management as a tool to improve the conservation of endemic floras: the case of Sicily, Malta and their satellite islands

The presence of endemic species is among the fundamental criteria for characterizing the biodiversity of a territory. Analyzing species richness, extinction level and distribution drivers is an important preliminary step to set conservation priorities and test environmental policies. This study applied the concept of adaptive management to develop strategies for the conservation of endemic floras by considering, as a case study, Sicily, Malta and their neighboring small islands. Adaptive management can be defined as the systematic acquisition and application of reliable information to improve management over time. The development of adaptive conservation strategies aimed preliminary: (1) to quantify endemic plant diversity; (2) to assess the current IUCN knowledge; (3) to analyze the spatial patterns of species distribution in relation to number of colonized habitats, preferential habitats, altitudinal range, and bedrock; (4) to assess whether Natura 2000 network contributed significantly to increase the overlap between endemic distributional areas and protected surface. Strictly Sicilian endemics were 202 taxa amounting to 7.0 % of the whole native flora (c. 2900 taxa). The current picture of extinction risk is still incomplete because over 50 % of endemics were never assessed or assessed with old IUCN criteria. The spatial range size of endemics depended by 40 % on bedrock, and altitudinal and niche breadth. Habitat type did not influence the range size of endemics. The overlap between endemic distributional areas and protected surface increased from 41.3 to 63.3 % with Natura 2000. Adaptive management needs measurable goals to test the progressive improvement of conservation strategies over time, and the reduction in threatened species may be considered as an indicator of successful conservation outcomes. Feedback plays an important role in the periodic revision of biodiversity assessment, distribution modeling, and environmental management, which are fundamental to predict conservation outcomes in the face of extreme uncertainty. In particular, the exhaustive knowledge of the IUCN status is a primary step to implement adaptive measures of conservation, especially as regards endemic floras that are potentially more vulnerable to large-scale or unpredictable and stochastic threats.