Distribution,status and conservation of Lilium polyphyllum (Liliaceae), a critically endangered medicinal plant from India

Field survey conducted to understand habitat, distribution, population structure and conservation status of Lilium polyphyllum. Three populations (total 649 individuals) are in decline because of habitat degradation, agriculture invasion and over exploitation. Our finding confirmed critically endangered status of the species, although with new criteria. We recommended integrated conservation plan.     

Habitat suitability modelling to improve conservation status of two critically endangered endemic Afromontane forest bird species in Taita Hills,Kenya

Tropical montane forests are known to support many endemic species with restricted geographic ranges. Many of these species are however, faced with numerous threats, most notably from habitat loss and degradation, invasive alien species, and climate change. Examples include Taita Apalis and Taita Thrush. Taita Apalis (Apalis fuscigularis) and Taita Thrush (Turdus helleri) are species of birds listed as Critically Endangered by the Government of Kenya and the International Union for Conservation of Nature (IUCN). They are endemic to Taita Hills’ cloud forests in southeastern Kenya and protected under Wildlife Conservation and Management Act. As they face high risk of extinction, exploring their habitat suitability is imperative for their protection. To determine the current spatial distribution and the key ecogeographical explanatory factors and conditions affecting species distribution and indirect effects on species survival and reproduction, we employed Maximum Entropy (MaxEnt) modelling. This study was conducted in Ngangao and Vuria forests in June and July 2019 and 2020. Ngangao forest is gazetted as forest reserve and managed by the Kenya Forest Service whereas Vuria is non-gazetted and thus remains without official protection status. Ecogeographical explanatory variables; climatic, remote sensing-, LIDAR-, topography- and landscape-based variables were used in modelling and separate models were produced. 23 occurrence records of Taita Apalis and 30 of Taita Thrush from Ngangao and 21 of Taita Apalis from Vuria forests were used in the modelling. According to the models, less than 7% of the total area of Ngangao and Vuria forests was predicted as suitable habitat for Taita Apalis and Taita Thrush. This shows that these two species are more vulnerable to extinction from demographic stochasticity. Consequently, managing their habitats is critical for their long-term persistence. LIDAR-based canopy height range and elevation greatly influenced Taita Apalis distribution in Ngangao forest, with areas of high elevation (1620–1750 m a.s.l.) and having open middle-storey preferred. Elevation, slope and topographic wetness index (twi) were the major determinants of Taita Thrush distribution in Ngangao, where gentle sloping areas with moderately dry surfaces within high elevation (1620–1730 m a.s.l.) were favoured. Mean annual temperature, Euclidean distance to the forest edge, slope and land cover type greatly influenced the distribution of Taita Apalis in Vuria, with gentle sloping areas within forest interior made up of indigenous vegetation preferred. This study proposes reforesting open and degraded sites next to areas predicted as highly suitable for the two species; establishment of agroforestry belts based on indigenous trees on the boundaries of the two forests to reduce grazing and firewood collection pressure and enhance resilience to the edge effects; and enhancing forest protection through Participatory Forest Management.     

Tsunami impact on the population development of a critically endangered hummingbird species of a Pacific island

It is a long-standing question how tsunamis can influence wild populations of animals and plants. Here, we assessed short-term changes in the population of the critically endangered Juan Fernández Firecrown (Sephanoides fernandensis) by using abundance data recorded 1 year before and 1 year after the 2010 Chilean tsunami. We tested that the abundance of Firecrowns declined in the areas where the tsunami caused the massive loss of Cabbage Trees, an important seasonal nectar source for Firecrowns. The abundance of Juan Fernández Firecrowns decreased after the tsunami, but also was affected by the habitat type, altitude, and the abundance of Cabbage Trees. Firecrowns tended to be more abundant in settlement areas than in native forest whereas the reduction in Firecrown abundance after the tsunami was more intense in settlement areas than in native forest. As expected, this habitat effect was dependent on the massive loss of Cabbage Trees in settlement areas following the tsunami. In spite of the short-term nature of our data, our results are conclusive in showing that the loss of an important food source causes short-term changes in the distribution and abundance of Firecrowns, which, in turn, could contribute to population decline.     

Evaluation of Bayesian networks for modelling habitat suitability and management of a protected area

To be effective, management of protected areas should be based on the best available evidence, including the scientific literature and expert knowledge. However, lack of such evidence in a suitable form to support decision-making may hinder effective management. Here we examine the use of Bayesian networks to support the management of protected areas, through the development of habitat suitability models for eight species of conservation concern. Bayesian networks were constructed on the basis of the scientific literature and expert knowledge, and were then tested using results from a field survey. Models of all species demonstrated very high discrimination between presence and absence sites, as indicated by AUC values >0.8, with values >0.9 obtained for four species, and Kappa values in the range of 0.4–0.9. The Bayesian networks were then used to examine the impact of different management interventions on habitat suitability of each species, including tree cutting, grazing and burning. Species differed in terms of their sensitivity to different management interventions, and model output provided evidence of both negative and positive interactions between types of intervention. These results highlight the trade-offs that must often be made when undertaking conservation management, and demonstrate the value of Bayesian networks in helping to make such trade-offs explicit. The identification of management impacts through analysis of available evidence also demonstrates the value of Bayesian networks for supporting evidence-based approaches to protected area management.     

Population genetics and conservation priorities for the critically endangered island endemic Delphinium pentagynum subsp. formenteranum (Ranunculaceae)

Isozyme electrophoresis was used to evaluate levels of genetic diversity and population genetic structure of the critically endangered (CR) perennial larkspur, Delphinium pentagynum subsp. formenteranum (Ranunculaceae), endemic to the island of Formentera (Balearic Islands, Spain). There is only one known population for this taxon, containing only 480 individuals. Moderate values of diversity were detected (P = 40.7%, A = 1.6 and H _e = 0.180), within the range observed in other surveyed larkspurs, but higher than most island endemics. Moderate levels of inbreeding were detected, probably as a consequence of the population's genetic structuring (biparental inbreeding). Threats to this taxon are mainly anthropogenic (fires, grazing, pathway works, and building pressures), although given that only one population exists, stochastic risks cannot be ignored. Conservation of D. pentagynum subsp. formenteranum requires in situ strategies, such as implementing a monitoring program and establishing a botanical reserve, and ex situ strategies, such as collection and long-term storage of seeds.     

Achieving Target 2 of the Global Strategy for Plant Conservation: building a preliminary assessment of vascular plant species using data from herbarium specimens

The Global Strategy for Plant Conservation calls for a preliminary assessment of the conservation status of all known plant species by the year 2010. To date insufficient progress has been made on meeting this target. New efforts to develop a preliminary list beyond using the full IUCN criteria in plant assessments are needed. Here we present an algorithm that provides a preliminary assessment of the conservation status of plant species using data from herbarium specimens. We use Hawaiian specimen data from the United States National Herbarium to calibrate the parameters of the algorithm and then use specimen data from the Arecaceae, Commelinaceae, Gesneriaceae and Heliconiaceae as examples of the application of the algorithm. The algorithm was calibrated to insure 95% accuracy in placing the Hawaiian plant species into previously and independently determined threatened categories. Our results indicate that 28% of the Hawaiian taxa, 27% of the species of Arecaceae, 45% of the species of Commelinaceae, 32% of the species of Gesneriaceae, and 35% of the species of Heliconiaceae are Not Threatened and will not need any further evaluation for the preliminary assessment. Species identified here as Potentially Extinct and Potentially Threatened can be further assessed by additional herbarium material and/or conservation specialists for final evaluation using other assessment strategies (e.g., regional and national lists, taxonomic expert assessment, etc.).     

Development of 12 microsatellite markers for Aconitum brachypodum (Ranunculaceae), a critically endangered and endemic medicinal plant

In this study, 12 microsatellite markers were developed from two microsatellite-enriched libraries (AG, AC) of Aconitum brachypodum, which were constructed using a FIASCO method. Polymorphism of each locus was assessed in 24 individuals of A. brachypodum. Number of alleles per locus (N_A) ranged from 2 to 4. The average allele number of the microsatellites was 2.58 per locus. The observed (H_O) and expected (H_E) heterozygosities ranged from 0.125 to 0.875 and 0.117 to 0.612, respectively. Polymorphic information content (PIC) ranged from 0.110 to 0.531. Among the 12 microsatellite markers, three deviated from Hardy–Weinberg equilibrium significantly. These markers will facilitate further studies on the population genetics of A. brachypodum.     

Estimating the population size of an endangered shorebird, the Madagascar plover, using a habitat suitability model

The Madagascar plover Charadrius thoracicus is a shorebird endemic to western Madagascar, currently classified as globally vulnerable. It is restricted to specialized wetland habitats that are increasingly threatened by humans. To inform future conservation measures for this poorly known species, we develop a predictive habitat suitability map and use this map to estimate the size of the Madagascar plover population. We integrate spatially referenced presence-only observations of Madagascar plovers with Landsat data, elevation data and measures of distance to settlements and the coast to produce a habitat suitability model using ecological niche factor analysis. Validation of this model using a receiver operating characteristic plot suggests that it is at least 84% accurate in predicting suitable sites. We then use our estimate of total area of suitable habitat above a critical suitability threshold and data on Madagascar plover density in suitable sites to estimate the total population size to derive a total population estimate of 3100±396 standard error individuals. Finally, we explore the conservation applications of our model.     

The role of the soil seed bank in the unpredictable habitat of Anthemis chrysantha J. Gay,a critically endangered species

The ability of Anthemis chrysantha to form a soil seed bank (SB) was investigated in order to understand better the adaptation of this rare annual species to its arid and unpredictable natural habitat. The natural seed bank population was analyzed in five consecutive plant cohorts (2006–2010) by sampling at two different times: in May, after the germination period, and in October, after the first dispersal episodes due to the beginning winter rainfall. In addition, to determine the persistence in the soil of the two achene morphs of this species’ (white and dark achenes), an artificial SB was created where achenes were buried and exhumed successively after each season, during two years. In all the cohorts studied, seedling emergence from May samples indicated the existence of a persistent seed bank (PSB). Moreover, the dark achenes were largely responsible for the permanent fraction because, after two years of burial in the artificial SB, 85.0% of them remained apparently healthy without having germinated, versus 9.9% of white achenes. Both types of buried achenes exhibited an annual conditional dormancy/non-dormancy cycle, induced by low winter temperatures. The PSB dynamics appeared to oscillate between the minimum values at the end of the germination period in spring (up to 2000 achenes per square meter) and the maximum values of the dispersal episodes in early autumn (up to 6000 achenes per square meter), with fluctuations of achene density due to the variability in annual rainfall. Hence, the SB showed a decline due to the failure of fruiting in the 2008 cohort, caused by drought, although the low value of ca. 560 achenes per square meter was able to establish the following population. Our study highlights the importance of the PSB, which, in “bad” years, may be critical for the persistence of this species.     

Isolation and characterization of microsatellite markers in Dysosma versipellis (Berberidaceae), a rare endemic from China

Dysosma versipellis (Berberidaceae) is an important threatened medicinal plant (TMP) species. Here we isolated nine polymorphic microsatellite loci from D. versipellis using a modified biotin-capture method. Our isolated loci provided SSR markers with polymorphism of 2–7 alleles per locus. The expected and observed heterozygosities ranged from 0.507 to 0.864 and from 0.360 to 0.720, respectively. These markers would be the useful tools for analyzing questions concerning population genetic structure and mating system of D. versipellis.     

Development and characterization of microsatellite loci in the endangered Tricyrtis ishiiana (Convallariaceae), a local endemic plant in Japan

Nine microsatellite loci were isolated and characterized for the endangered and tertiary relict perennial herb, Tricyrtis ishiiana. The number of alleles ranged from 2 to 33. The expected (H _E) and observed (H _O) heterozygosities were 0.207–0.944 and 0.215–0.813, respectively, from 96 individuals on one population. Five loci exhibited significantly fewer heterozygotes than expected under Hardy–Weinberg equilibrium (P < 0.05). These primers amplifying microsatellites in this species may provide a useful tool for population genetics to establish conservation strategy.     

Development of microsatellite markers for <Emphasis Type="Italic">Metrosideros boninensis</Emphasis> (Myrtaceae), an endangered endemic plant species from the Bonin Islands,Japan

Metrosideros boninensis is an endangered endemic plant species from the Bonin Islands. We isolated and characterized nine microsatellite loci in this species. The expected heterozygosities of these nine markers ranged from 0.127 to 0.768. These markers described here will be useful for investigating the genetic diversity, genetic structure and gene flow, and planning for conservation of M. boninensis.     

Micropropagation of <Emphasis Type="Italic">Drosophyllum lusitanicum</Emphasis> (Dewy pine), an endangered West Mediterranean endemic insectivorous plant

In this work, in vitro clonal propagation of Drosophyllum lusitanicum (Dewy pine) was obtained from seedlings germinated in vitro. Seeds were collected in various populations identified in the Algarve region and germinated in vitro on MS medium supplemented with 0.5 mg l^–1 BA (6-benzyladenine) and 0.1 mg l^–1 GA₃ (gibberellic acid). The obtained shoots were used in several multiplication assays. The best results were observed in MS medium supplemented with 0.2 or 0.5 mg l^–1 zeatin. The highest rooting frequency (83%) was observed on 1/4MS medium supplemented with 0.2 mg l^–1 IBA (indole-3-butyric acid). Fifty percent of the plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development. Plans are underway to reintroduce the in vitro produced plants from this study in selected locations in their natural habitat.     

Micropropagation from inflorescence stems of the Spanish endemic plant Centaurea paui Loscos ex Willk. (Compositae)

Tissue culture techniques have been established as a useful approach for ex situ conservation of rare, endemic or threatened plant species. This report describes the micropropagation of Centaurea paui Loscos ex Willk (Compositae), an extremely endangered plant species endemic to the Valencia Community (eastern Spain), as a conservation measure which does not cause damage to the wild plants used as explant source. Inflorescence nodal segments of C. paui were selected as explants for in vitro establishment. The best rate of shoot proliferation was obtained on Murashige and Skoog (MS) mineral medium supplemented with 0.5 mg/l 6-benzyladenine or with 2 mg/l kinetin. Maximum shoot elongation was achieved without growth regulators, and the addition of cytokinins significantly decreased their size. In vitro rooting of shoots was difficult after 6 weeks on rooting media. The combination of 2 mg/l indole-3-acetic acid plus 2 mg/l indole-3-butyric acid on MS medium yielded the best results. In this medium, 40% of shoots rooted before 30 days of culture. About 70% of the rooted plants were successfully transferred to pots and acclimatized to ex vitro conditions. Received: 12 January 1998 / Revision received: 10 October 1998 / Accepted: 28 October 1998     

Prediction of habitat suitability,connectivity, and corridors in the future to conserve roe deer (Capreolus capreolus) as a locally endangered species in northern Iran

Roe deer is a protected species in Iran as its population and distribution in the country have considerably declined. Roe deer are threatened by several factors such as habitat fragmentation and road mortality, so studying their distribution and movement through the increasing habitat destruction and fragmentation is necessary. This will become increasingly important because climate change will transform the species’ future habitat and connectivity patterns. We evaluated the roe deer’s potential distribution range in northern Iran and, for the first time, developed connectivity models and designed corridors for the present and future to make better conservation plans. We collected 91 points indicating the presence of roe deer in the study region. After developing ensemble models using six species distribution algorithms, we defined high-ranked habitat cores using the concept of landscape suitability prioritization. From these, we designed connectivity and corridors in two time-frames with the help of least-cost paths and circuit theories to predict the potential movement throughout the study area. We estimated that the overall core habitats for roe deer in the present and future periods are, respectively, around 1200 km² and 2600 km², corresponding to 2 and 4 percent of the whole area. This suggests that the habitat core will expand in the future as a result of climate change. Similarly, the connectivity among the cores will strengthen. We also conclude that the temperature-driven and anthropogenic variables significantly affect the distribution of roe deer in northern Iran. It is necessary that conservationists and managers consider the designed corridors in the present study while planning conservation strategies.     

Prediction of climate warming impacts on plant species could be more complex than expected. Evidence from a case study in the Himalaya

Many studies have investigated the possible impact of climate change on the distributions of plant species. In the present study, we test whether the concept of potential distribution is able to effectively predict the impact of climate warming on plant species.Using spatial simulation models, we related the actual (current species distribution), potential (modelled distribution assuming unlimited dispersal) and predicted (modelled distribution accounting for wind-limited seed dispersal) distributions of two plant species under several warming scenarios in the Sagarmatha National Park (Nepal). We found that the two predicted distributions were, respectively, seven and nine times smaller than the potential ones. Under a +3 °C scenario, both species would likely lose their actual and predicted distributions, while their potential distributions would remain partially safe. Our results emphasize that the predicted distributions of plant species may diverge to a great extent from their potential distributions, particularly in mountain areas, and predictions of species preservation in the face of climate warming based on the potential distributions of plant species are at risk of producing overoptimistic projections.We conclude that the concept of potential distribution is likely to lead to limited or inefficacious conservation of plant species due to its excessively optimistic projections of species preservation. More robust strategies should utilize concepts such as “optimal reintroduction”, which maximizes the benefit–cost ratio of conservation activities by limiting reintroduction efforts to suitable areas that could not otherwise be reached by a species; moreover, such strategies maximize the probability of species establishment by excluding areas that will be endangered under future climate scenarios.     

Genetic diversity of the endangered Chinese endemic herb Saruma henryi Oliv. (Aristolochiaceae) and its implications for conservation

Saruma henryi Oliv., the only representative of the monotypic genus Saruma Oliv. (Aristolochiaceae), is an endangered perennial herb endemic to China. It is a phylogenetically, ecologically, and medicinally important species. In the present study, inter-simple sequence repeat (ISSR) markers were employed to investigate the genetic diversity and differentiation of 14 populations. A total of 16 selected primers yielded 175 bright and discernible bands, with an average of 10.94 per primer. POPGENE analysis showed that the genetic diversity was quite low at the population level (h = 0.0447–0.1243; I = 0.0642–0.1853; PPB = 10.29–36.57%), but pretty high at the species level (h = 0.2603; I = 0.3857; PPB = 73.71%). The hierarchical analysis of molecular variance (AMOVA) revealed a high level of genetic differentiation among populations (67.18% of total variance components, P < 0.001), in line with the gene differentiation coefficient (G _ST = 0.6903) and the limited among-population gene flow (N _m = 0.2243). Both Principal Coordinates Analysis (PCoA) and UPGMA cluster analysis supported the grouping of all 14 populations into three geographic groups, among which there occurred a moderate level of genetic differentiation (33.18% of total variance components, P < 0.001) as shown by AMOVA analysis. In addition, Mantel test revealed a significant correlation between genetic and geographic distances among populations (r = 0.7792, P = 0.001), indicating the role of geographic isolation in shaping its present population genetic structure. The present levels and patterns of genetic diversity of S. henryi were assumed to result largely from its breeding system, geographic isolation, clonal growth, its unique biological traits and evolutionary history. The high genetic differentiation among populations implies that the conservation efforts should aim to preserve all the extant populations of this endangered herb.     

Assessing extinction-risk of endangered plants using species distribution models: a case study of habitat depletion caused by the spread of greenhouses

The species distribution models (SDMs) are useful tools for investigating rare and endangered species as well as the environmental variables affecting them. In this paper, we propose the application of SDMs to assess the extinction-risk of plant species in relation to the spread of greenhouses in a Mediterranean landscape, where habitat depletion is one of the main causes of biodiversity loss. For this purpose, presence records of the model species (Linaria nigricans, a endemic and threatened species) and the greenhouses, a dataset of environmental variables, and different only presence-based modelling algorithms (Bioclim, Domain, GARP, MaxEnt and ENFA) were used to build SDMs for L. nigricans as well as for greenhouses. To evaluate the models a modified approach of the area-under-curve ROC was applied. Combining the most accurate models, we generated an extinction-risk model of L. nigricans populations, which enabled us to assess the sustainability of the most threatened populations. Our results show that is possible to model greenhouses spreading as a “biological invasion”. The procedure explained and used in this work is quite novel, and offers an objective spatial criterion intended for the management of natural resources and for the conservation of the biodiversity in areas threatened by habitat depletion processes as particular as greenhouses expansion.     

Relevance of exotic pine plantations as a surrogate habitat for ground beetles (Carabidae) where native forest is rare

Plantation forests are of increasing importance worldwide for wood and fibre production, and in some areas they are the only forest cover. Here we investigate the potential role of exotic plantations in supporting native forest-dwelling carabid beetles in regions that have experienced extensive deforestation. On the Canterbury Plains of New Zealand, more than 99% of the previous native forest cover has been lost, and today exotic pine (Pinus radiata) plantations are the only forest habitat of substantial area. Carabids were caught with pitfall traps in native kanuka (Kunzea ericoides) forest remnants and in a neighbouring pine plantation, grassland and gorse (Ulex europaeus) shrubland. A total of 2,700 individuals were caught, with significantly greater abundance in traps in young pine, grassland and gorse habitats than in kanuka and older pine. Rarefied species richness was greatest in kanuka, a habitat that supported two forest specialist species not present in other habitat types. A critically endangered species was found only in the exotic plantation forest, which also acts as a surrogate habitat for most carabids associated with kanuka forest. The few remaining native forest patches are of critical importance to conservation on the Canterbury Plains, but in the absence of larger native forest areas plantation forests are more valuable for carabid conservation than the exotic grassland that dominates the region.