Conservation value of secondary forest habitats for endemic birds,a perspective from two widely separated tropical ecosystems

Tropical secondary forests are increasingly widespread, but their potential for conserving endemic birds remains unclear. Previous studies report different results; however all have been restricted to geographically discreet locations. This is important as different ecosystems are influenced by different external factors, possibly influencing conservation potential. Here we use consistent survey methods to examine how endemic bird richness varies between primary and secondary forest habitats in two widely separated tropical ecosystems, providing a more global context for evaluating the conservation value of secondary forests. Research was completed in Lambusango Forest Reserve (LFR) on Buton Island, Sulawesi, and Cusuco National Park (CNP), a Honduran cloud forest reserve. Bird communities in both forests were surveyed using 50 m radius point counts. Vulnerability assessments based on ecological theory on avifaunal assemblages were then conducted, which suggested endemics in LFR to be more susceptible to disturbance than those in CNP. Contrary to the results from our vulnerability assessments, endemics in CNP were less tolerant of moderate habitat modification than those in LFR. Richness of Mesoamerican endemics per study site declined significantly between core zone forest (6.34 ± 0.81) and more degraded forest in the boundary zone (3.86 ± 0.69). Richness of Wallacean endemics was similar in primary (4.89 ± 1.68) and disturbed secondary forest (4.52 ± 1.62). We recommend considering local and regional biogeographical and ecological factors when determining the conservation value of secondary forests, and suggest examples of potential importance, including differential community richness, influence of figs and human settlement patterns.     

The diversity of cloud forest birds on the eastern and western slopes of the Ecuadorian Andes: a latitudinal and comparative analysis with implications for conservation

We studied the avifaunas of five cloud forest localities at 3000–3350 mas1 on the eastern slope of the Andes of Ecuador A method standardised for area, altitude and effort was the basis for obtaining data on species richness and abundances Richness and abundances (diversity) were unchanged along the limned latitudinal gradient (530 km) studied, whereas there was a considerable turnover in community structure between localities This result has important implications for ranking conservation priorities the total community richness and the dominance/evenness component of diversity does not provide a basis for making priorities along this limited latitudinal gradient Instead, species compositions and species referred to threatened categories (e g, endemics, restricted–range, IUCN threatened/near–threatened, CITES) will be the most meaningful data for making priorities for conservation We compared our results with similar results from the Andean western slope of Ecuador, obtained with the same method and standardised for time of the year The number of species was significantly higher on the eastern slope than on the western slope, a characteristic that can be explained from differences in extension of adjacent source areas and geohistory However, because the species compositions on the two slopes are rather different, it is not recommended to use the difference in richness to rank conservation priorities Abundances were quite similar on both sides of the Andes Contrary to the general belief, the montane avifaunas investigated have tropical and not temperate species richness which agrees with the tropical clutch sizes found among montane birds The avian richness found on the eastern slope of Ecuador near the Equator is definitely among the highest m the world for this altitude     

The effects of land-use change on arthropod richness and abundance on Santa Maria Island (Azores): unmanaged plantations favour endemic beetles

We study how endemic, native and introduced arthropod species richness, abundance, diversity and community composition vary between four different habitat types (native forest, exotic forest of Cryptomeria japonica, semi-natural pasture and intensive pasture) and how arthropod richness and abundance change with increasing distance from the native forest in adjacent habitat types in Santa Maria Island, the Azores. Arthropods were sampled in four 150 m long transects in each habitat type. Arthropods were identified to species level and classified as Azorean endemic, single-island endemic (SIE), native, or introduced. The native forest had the highest values for species richness of Azorean endemics, SIEs and natives; and also had highest values of Azorean endemic diversity (Fisher’s alpha). In contrast, the intensive pasture had the lowest values for endemic and native species richness and diversity, but the highest values of total arthropod abundance and introduced species richness and diversity. Arthropod community composition was significantly different between the four habitat types. In the semi-natural pasture, the number of SIE species decreased with increasing distance from the native forest, and in the exotic forest the abundance of both Azorean endemics and SIEs decreased with increasing distance from the native forest. There is a gradient of decreasing arthropod richness and abundance from the native forest to the intensive pasture. Although this study demonstrates the important role of the native forest in arthropod conservation in the Azores, it also shows that unmanaged exotic forests have provided alternative habitat suitable for some native species of forest specialist arthropods, particularly saproxylic beetles.     

Cross-taxon congruence in tree,bird and bat species distributions at a moderate spatial scale across four tropical forest types in the Philippines

Indicator species groups are often used as surrogates for overall biodiversity in conservation planning because inventories of multiple taxa are rare, especially in the tropics where most biodiversity is found. At coarse spatial scales most studies show congruence in the distribution of species richness and of endemic and threatened species of different species groups. At finer spatial scale levels however, cross-taxon congruence patterns are much more ambiguous. In this study we investigated cross-taxon patterns in the distribution of species richness of trees, birds and bats across four tropical forest types in a ca. 100 × 35 km area in the Northern Sierra Madre region of Luzon Island, Philippines. A non-parametric species richness estimator (Chao1) was used to compensate for differential sample sizes, sample strategies and completeness of species richness assessments. We found positive but weak congruence in the distribution of all and endemic tree and bird and tree and bat species richness across the four forest types; strong positive congruence in the distribution of all and endemic bat and bird species richness and low or negative congruence in the distribution of globally threatened species between trees, birds and bats. We also found weak cross-taxon congruence in the complementarity of pairs of forest types in species richness between trees and birds and birds and bats but strong congruence in complementarity of forest pairs between trees and bats. This study provides further evidence that congruence in the distribution of different species groups is often ambiguous at fine to moderate spatial scales. Low or ambiguous cross-taxon congruence complicates the use of indicator species and species groups as a surrogate for biodiversity in general for local systematic conservation planning.     

Water links the historical and contemporary components of the Australian bird diversity gradient

Aim To document the geographical structure of the historical signal in the continental species richness gradient of birds and evaluate the influences of contemporary and historical climatic conditions on the generation and maintenance of the richness pattern. Location Australia. Methods We used range maps of breeding birds to generate the spatial pattern of species richness at four grain sizes, and two molecular phylogenies to measure the level of evolutionary development of avifaunas at each grain size. We then used simple correlation and path analysis to generate a statistical model of species richness using environmental predictor variables and compared the spatial patterns of richness and mean evolutionary development to identify possible environmental links between richness and net diversification rates across the continent. Results The contemporary richness pattern is well explained statistically by actual evapotranspiration (a measure of water–energy balance), operating both directly and indirectly through plant production, and this is robust to the spatial resolution of the analysis. Further, species richness and the mean level of evolutionary development of faunas show a strong spatial correspondence, such that dry areas support both fewer species and species from more highly derived families, whereas wet areas support more species of both basal and derived families. The evolutionary pattern conforms to a similar pattern known for plants and is probably explained by the increase in aridity in western and central Australia arising in the Miocene. Main conclusion The contemporary bird richness gradient contains a historical signal and reflects the effects of both current levels of water availability as well as changes in rainfall patterns extending over evolutionary time. The historical signal persists even in the absence of obvious hard barriers to dispersal.     

Distributional patterns of the Neotropical humid montane forest avifaunas

The study of biogeographical patterns of the Neotropical humid montane forest avifauna has been prevented due to the lack of phylogenetic hypotheses for most taxa, and to the paucity of detailed studies about the geographical distribution for most of the species. Distributional patterns of this avifauna were explored by integrating predictive distributional models and Parsimony Analysis of Endemicity (PAE). Distributional maps were generated using the Genetic Algorithms for Rule Set Prediction for 442 species; this information was transformed into a data matrix for analysis with PAE. Hierarchical information corresponding to the genus level was incorporated to help resolve the relationships between areas. A strict consensus cladogram showed a clear separation between the Mesoamerican and South American avifaunas. Within the Mesoamerican clade, three geographically structured groups were obtained, whereas the South American clade showed a polytomy of three groups, with two of them, the South Andean Yungas and the Tepuis, located outside the main clade. The third group is a well resolved clade, including areas from eastern Panama and northern Venezuela to central Bolivia. Area relationships suggest a mixed history of dispersal and vicariant events, with the latter being the most important for explaining the biogeographical patterns found.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 175–194.     

Biogeographical patterns of endemic terrestrial Afrotropical birds

Biogeographical zones are described for terrestrial bird species endemic to the Afrotropics using up‐to‐date distributional data and multivariate statistical techniques. This provides an objective basis for a hierarchy of subregions, provinces and districts, based on a set of rules. Results are compared to previous studies at continental and regional scales. Biogeographical zones for passerines and non‐passerines are compared and found to be similar. Peaks of species richness and narrow endemism are described for the six major subdivisions (subregions) identified by the cluster analysis. Coincidence of peaks of species richness and narrow endemism is found to be low, such that areas selected to represent high species richness tallies will often fail to represent narrow endemics. Strong regionalization of Afrotropical birds indicates the need to use a biogeographical framework in conservation priority setting exercises to ensure that unique, but species‐poor, avifaunas are not neglected.     

Avian distribution patterns in the Guiana Shield: implications for the delimitation of Amazonian areas of endemism

Aim To develop a methodology for defining the boundaries of the Guianan area of endemism using complementary approaches that include GIS tools, multivariate statistics and analyses of physical barriers in the distribution patterns of an entire endemic avifauna. As a case study, I used the distribution patterns of lowland terra firme forest birds. Location Guiana Shield, northern South America. Methods I identified Guianan endemics using the ornithological literature, subsequently gathering distributional data for these taxa using mainly museum collections and my own fieldwork in the region. I used these distributional data to map the spatial patterns of endemicity in the region and to compare distributions across taxa. I employed community composition data from 34 localities from throughout the Guiana Shield to identify spatial patterns of clustering using an ordination analysis (non‐metric multidimensional scaling), and to recognize the region’s main biogeographical barriers for birds using Monmonier’s algorithm. Results At least 88 avian taxa are restricted to the terra firme forests of the Guianan area of endemism, which is roughly delimited by the Amazon, Negro and Branco rivers. These large rivers, however, are not the only boundaries. I identified seven additional barriers, including medium‐sized rivers, non‐forested areas and mountains, which also contribute to delimiting the area of endemism. Within the endemic avifauna, I identified three distinct distribution patterns. The ordination analysis shows the presence of two distinct avifaunas within the Guiana Shield. Main conclusions Although the proposed boundaries of the Guianan area of endemism are consistent with previously postulated configurations, this study reveals a more complex delimitation than formerly recognized, highlighting the importance of several landscape features besides large rivers, and the existence of three distinct distributional patterns within one endemic avifauna. The Branco/Negro interfluvium, often included within this area of endemism, actually represents a transition zone between two distinct avifaunas. The longstanding view of the Amazon Basin as a mosaic of parapatric areas of endemism delimited by major rivers appears to be an oversimplification, at least for the Guiana Shield. This finding suggests the need for more rigorous approaches to re‐evaluate the traditional boundaries of such areas.     

Butterfly,spider, and plant communities in different land-use types in Sardinia,Italy

Butterfly, spider, and plant species richness and diversity were investigated in five different land-use types in Sardinia. In 16 one-hectare plots we measured a set of 15 environmental variables to detect the most important factors determining patterns of variation in species richness, particularly endemicity. The studied land-use types encompassed homogeneous and heterogeneous shrublands, shrublands with tree-overstorey, Quercus forest and agricultural land. A total of 30 butterfly species, among which 10 endemics, and 50 spider (morpho)species, were recorded. Butterfly and spider community composition differed according to land-use type. The main environmental factors determining diversity patterns in butterflies were the presence of flowers and trees. Spiders reacted mainly to habitat heterogeneity and land-use type. Traditional land-use did not have adverse effects on the diversity of butterflies, spiders, or plants. The number of endemic butterfly species per treatment increased with total species richness and altitude. Butterfly and spider richness did not co-vary across the five land-use types. Butterflies were, however, positively associated with plant species richness and elevation, whereas spiders were not. Conclusively, butterflies did not appear to be good indicators for spider diversity and species richness at the studied sites.     

The Hitchhiker’s guide to island endemism: biodiversity and endemic perennial plant species in roadside and surrounding vegetation

Roadsides are habitats with very specific environmental conditions, often substantially differing from their natural surroundings. However, roads can have a positive effect on local vascular plant species richness. Endemic species on oceanic islands are considered to be less disturbance-adapted than native non-endemics and thus should be negatively affected by roads. Islands provide optimal conditions for testing this, as they possess a large share of clearly defined endemic species. This study focuses on a comparison of endemic plant species in roadside and surrounding communities and the interacting effects of elevation, vegetation type and trade wind-induced precipitation differences. We applied 96 circular plots with 50 m radius along two elevational gradients on the eastern (humid) and western (dry) slope of La Palma, Canary Islands, ranging from 100 to 2,400 m. Interestingly, we found roads to have a significant positive effect on endemic richness and the percentage of endemics as well as the same tendency for plant species richness after correcting for elevation and precipitation. Endemic species turnover was relatively high. The opening of cliffs during construction and, not to be overlooked, the protection from disturbances such as fire and omnipresent introduced herbivores (mainly rabbits or goats) probably leads to a positive effect of roads on endemics. In addition, many endemics might profit from species-specific dispersal capabilities well suited for roadside conditions. However, we do not argue for the use or even construction of roads for nature conservation but suggest protecting existing endemic populations because natural areas have a higher conservation value.     

Elevational patterns of frog species richness and endemic richness in the Hengduan Mountains, China: geometric constraints, area and climate effects

We studied frog biodiversity along an elevational gradient in the Hengduan Mountains, China. Endemic and non-endemic elevational diversity patterns were examined individually. Competing hypotheses were also tested for these patterns. Species richness of total frogs, endemics and non-endemics peaked at mid-elevations. The peak in endemic species richness was at higher elevations than the maxima of total species richness. Endemic species richness followed the mid-domain model predictions, and showed a nonlinear relationship with temperature. Water and energy were the most important variables in explaining elevational patterns of non-endemic species richness. A suite of interacting climatic and geometric factors best explained total species richness patterns along the elevational gradient. We suggest that the mid-domain effect was an important factor to explain elevational richness patterns, especially in regions with high endemism.     

Biogeographic patterns of the East African coastal forest vertebrate fauna

The archipelago-like coastal forest of East Africa is one of the highest priority ecosystems for biodiversity conservation worldwide. Here we investigate patterns of species richness and biogeographic distribution among birds, mammals and reptiles of these forests, using distribution data obtained from recently published reviews and information collated by the WWF Eastern Africa Coastal Forest Ecoregion Programme. Birds and mammals species were divided into forest specialists and generalists, and forest specialist reptiles into ‘coastal’ and ‘forest’ endemics. The species richness of birds and generalist mammals increased with area, and is probably a result of area-dependent extinction. Only in birds, however, species richness increased with decreasing isolation, suggesting possible isolation-dependent colonization. Forest diversity, associated to altitudinal range, is important for specialist birds and mammals, whose species richness increased with wider altitudinal range. The number of relict coastal endemic and forest endemic reptiles was higher in forests with wider altitudinal ranges and on relatively higher altitude, respectively. Such forests have probably provided a suitable (and perhaps stable) environment for these species through time, thus increasing their persistence. Parsimony analysis of distributions (PAD) and cluster analyses showed geographical distance and general ecological similarity among forests as a determinant factor in bird distribution patterns, with compositional similarity decreasing with increasing inter-forest distance. Compositional similarity patterns of mammals among the forests did not show a strong geographical correspondence or a significant correlation with inter-forest distance, and those of reptiles were not resolved, with very low similarity levels among forest faunas. Our results suggest that the relative importance (and causal relationship) of forest attributes affecting the distribution of the East African coastal forest vertebrate fauna varies depending on life history traits such as dispersal ability and forest specialization. The groupings in PAD are partly congruent with some of the previous classifications of areas of endemism for this region, supporting the ‘naturalness’ of these regions.     

Climatic and spatial patterns of diversity in the serpentine plants of California

Abstract . The insular distribution of distinctive substrates, such as outcrops of serpentine rock, may either promote plant diversity by enhancing opportunities for speciation or reduce diversity by increasing rates of extinction. To examine the relationship between diversity and the spatial structure of habitats, we studied large‐scale patterns of diversity in the flora of serpentine in California. We used multiple linear regressions on geographical information system (GIS)‐derived data for 85 subregions of the state to analyse the climatic and spatial correlates of plant species richness. The diversity of plants endemic to serpentine declined from north to south and from the coast inland, in association with decreasing rainfall; the same trends were seen in the total flora, but the trends were stronger in serpentine endemics. Diversity of serpentine endemics increased with the area of serpentine and decreased with the mean isolation of serpentine patches in a subregion. The diversity of endemics was not correlated with the number of serpentine patches or their mean perimeter‐to‐area ratio. We conclude that patchiness in this terrestrial habitat does not appear to promote diversity, even at the large spatial scale associated with speciation and endemism.     

Imprints of glacial history and current environment on correlations between endemic plant and invertebrate species richness

Aim We evaluate how closely diversity patterns of endemic species of vascular plants, beetles, butterflies, molluscs and spiders are correlated with each other, and to what extent similar environmental requirements or survival in common glacial refugia and comparable dispersal limitations account for their existing congruence. Location Austria. Methods We calculated pairwise correlations among species numbers of the five taxonomic groups in 1405 cells of a 3′ × 5′ raster (c. 35 km²) using the raw data as well as the residuals of regression models that accounted for: (1) environmental variables, (2) environmental variables and the occurrence of potential refugia during the Last Glacial Maximum, or (3) environmental variables, refugia and spatial filters. Results Pairwise cross‐taxonomic group Spearman’s rank correlations in the raw data were significantly positive in most cases, but only moderate (0.3 < ρ < 0.5) to weak (ρ < 0.3) throughout. Correlations were closest between plants and beetles, plants and butterflies, and plants and snails, respectively, whereas the distribution of endemic spiders was largely uncorrelated with those of the other groups. Environmental variables explained only a moderate proportion of the variance in endemic richness patterns, and the response of individual groups to environmental gradients was only partly consistent. The inclusion of refugium locations and the spatial filters increased the goodness of model fit for all five taxonomic groups. Moreover, removing the effects of environmental conditions reduced congruence in endemic richness patterns to a lesser extent than did filtering the influence of refugium locations and spatial autocorrelation, except for spiders, which are probably the least dispersal‐limited of the five groups. Main conclusions The moderate to weak congruence of endemic richness patterns clearly limits the usefulness of a surrogacy approach for designating areas for the protection of regional endemics. On the other hand, our results suggest that dispersal limitations still shape the distributions of many endemic plant, snail, beetle and butterfly species, even at the regional scale; that is, survival in shared refugia and subsequent restricted spread retain a detectable signal in existing correlations. Concentrating conservation efforts on well‐known Pleistocene refugia hence appears to be a reasonable first step towards a strategy for protecting regional endemics of at least the less mobile invertebrate groups.     

Role of climate and geohistorical factors in driving plant richness patterns and endemicity on the east Asian continental islands

We investigated the roles of climate, geography, and geology in plant diversity and endemicity on the east Asian continental islands, by testing predictions from contrasting hypotheses considering current climate, habitat stability, and isolation as major drivers of plant richness and endemicity. We created a fine‐resolution map of vascular plant richness (5614 species) with 10 × 10 km grid cells. Using this large dataset and regression models, we explored correlations between species richness/number of endemics and temperature, precipitation, Quaternary temperature/precipitation changes, Quaternary alluvial development and volcanic disturbances (presence of alluvial plains and of pyroclastic flows), distance from the continent, and elevation. We applied these analyses to the vascular plant assemblage as a whole and separately to trees, herbs, and ferns. Temperature and precipitation were associated with the richness of vascular plants overall and of their endemics. Quaternary temperature change was negatively associated with the richness of vascular plants overall and of their endemics. The presence of pyroclastic flows and of lowland alluvial plains was negatively associated with those. Distance from the continent and elevation were positively associated with endemic species richness, especially those of trees and herbs. While current climate was an important predictor of species richness (especially of ferns), geographical isolation and habitat stability were the main predictors of the endemic species richness of trees and herbs. The relative importance of current climate and historical factors may be related to the dispersal ability of functional groups. Our results illustrate that the diverse geographical conditions reflecting the characteristics of the island led to the various historical effects on biodiversity patterns. The highly endemic flora on the east Asian islands resulted from species accumulation and in situ diversification, suggesting that the climate and historical hypotheses are not mutually exclusive, but can be reconciled as the interplay between recent ecological and evolutionary processes.     

Burning and logging differentially affect endemic vs. widely distributed butterfly species in Borneo

We assess the differential impact of logging and ENSO (El Niño Southern Oscillation)-induced disturbance on the relative butterfly abundance and species richness of range-restricted and widespread species within the island of Borneo. Relative abundance and species richness were assessed using rarefaction and species accumulation curves in unburned isolates surrounded by burned forest, the burned forest itself, and continuous forest unaffected by ENSO-induced disturbance in addition to logged and unlogged landscapes in unburned forest. The relative abundance of endemics was significantly higher in unlogged forest than logged forest and significantly higher in unburned forest than burned forest. Rarefied species richness of range categories was similar (Bornean endemics) or higher (other categories) in selectively logged than unlogged forest. In contrast, rarefied species richness of range-restricted species was highest in continuous forest, intermediate in unburned isolates, and lowest in burned forest. Only two individuals of a single Bornean endemic species were found in all the burned forest. Although species richness was higher in all range categories in continuous forest than in unburned isolates and in burned forest, the difference was most pronounced for range-restricted species. Logging and ENSO-induced fires thus have contrasting effects on range-restricted species. While both increase the relative abundance of widely distributed species at the expense of range-restricted species, only ENSO-induced disturbance lowers the rarefied number of restricted range species. Our research highlights the threat that severe ENSO events pose to geographically restricted classes of biodiversity.     

Combined community ecology and floristics,a synthetic study on the upper montane evergreen broad-leaved forests in Yunnan,southwestern China

The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous, island-like, distribution. It is diverse, rich in endemic species, and likely to be sensitive to climate change. Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan. All trees with d.b.h. > 1 cm in each plot were identified. Patterns of seed plant distributions were quantified at the specific, generic and family levels. The forests are dominated by the families Fagaceae, Lauraceae, Theaceae and Magnoliaceae, but are very diverse with only a few species shared between sites. Floristic similarities at the family and generic level were high, but they were low at the specific level, with species complementarity between plots. Diversity varied greatly among sites, with greater species richness and more rare species in western Yunnan than central Yunnan. The flora is dominated by tropical biogeographical elements, mainly the pantropic and the tropical Asian distributions at the family and genus levels. In contrast, at the species level, the flora is dominated by the southwest or the southeast China distributions, including Yunnan endemics. This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin, and has adapted to cooler temperatures with the uplift of the Himalayas. Due to great sensitivity to climate, high endemism and species complementarity, as well as the discontinuous, island-like, distribution patterns of the upper montane forest in Yunnan, the regional conservation of the forest is especially needed.     

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.