Rediscovery of Pedilanthus coalcomanensis (Euphorbiaceae), a threatened endemic Mexican species

Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the type locality. Based on the reduced geographic distribution presently known for this species (11 km(2)), the level of disturbance of its habitat, and the use of the method for the assessment of extinction risk in Mexican wild species (MER), we propose that P. coalcomanensis be covered by the appropriate Mexican legislation as a threatened species and be included in the Red List of Threatened Plants of the International Union for the Conservation of Nature. Our results help justify and delimit a local biosphere reserve in northwestern Michoacán, an area that is considered a center of endemism and that has largely been deforested. Our findings have implications for research on other historical specimens collected by Hinton in this region.     

Natural hybridisation between two coastal endemic species of Armeria (Plumbaginaceae) from Portugal. 2. Ecological investigations on a hybrid zone

A clinal range of morphological variation between two coastal endemic species of the Genus Armeria in Portugal (A. pseudoarmeria and A. welwitschii) was investigated to test the hypothesis of hybrid advantage in contact zones between species. The putative F1 hybrids morphotypes could be submitted to endogenous selection as most of them show deficiencies in pollen fertility and seed setting in comparison with the parental species. Reciprocal transplant experiments in three sectors along the cline revealed that the intermediate F1 morphotypes are less productive in biomass than the parents even in their sector of origin. These data do not show evidence for the Hybrid Bound Superiority Model. Rather they are in favour of the Tension Zone Model where a dynamic balance is obtained between the continuous production of hybrids and the selection against them. Nevertheless the Tension Zone Model postulates similar fitness for the parents along the cline, which is not the case as the parents are clearly differentiated for nutrient uptake. Soil and plant leaf elemental analysis revealed that, in transplantation, some of the hybrids correspond to a geochemical specialisation diverging from that of the parents suggesting a local adaptation. Owing the high frequency and the healthy developmental aspect of the intermediate morphs in central and northern sector selection must be weak against hybrids. It is concluded that in natural situations the two models could not be strictly exclusive.     

In vitro multiplication ofVella lucentina M. B. crespo (Brassicaceae), a threatened Spanish endemic species

Summary Vella lucentina M. B. Crespo is a threatened Spanish species that is endemic to a small area in eastern Alicante Province (SE Spain). Micropropagation techniques were applied forex situ conservation of this plant. Aseptic epicotyls bearing the apical bud were grown in Murashige and Skoog medium supplemented with 6-furfurylaminopurine (Kin), N⁶-benzyladenine (BA) or 6-(γ,γ,-dimethilalylamino) purine (2iP). High multiplication rates were obtained with 0.5, 1, or 2 mg·liter⁻¹ BA, or 1 or 2 mg·liter⁻¹ 2iP. Indole-3-acetic acid and indole-3-butyric acid were utilized for rooting in half-strength Murashige and Skoog medium. Regenerated plants were transferred to a potting mix and gradually acclimated to field conditions. No morphological differences were observed amongin vitro andin vivo plants.     

Seed germination responses to salinity and temperature in Limonium supinum (Plumbaginaceae), an endemic halophyte from Iberian Peninsula

Limonium supinum, a perennial herb with interest for the restoration and gardening of arid zones, is widely distributed in saline areas from southeastern Iberian Peninsula. Laboratory experiments were carried out to assess the effects of temperature and salinity on seed germination and on germination recovery from the effects of saline conditions after transfer to distilled water. Seed germination responses were determined over a four temperature regimes (20/10, 25/15, 30/20 and 35/25 °C; 12 h light/12 h dark photoperiod) and six salinities (0, 100, 150, 200, 400 and 600 mM NaCl). The higher germination percentages were obtained in non-saline conditions, under all temperature regimes. An alternating temperature of 20 °C light and 10 °C dark yielded the maximum germination for any saline concentration. Increase in salinity delayed the beginning and end of germination and reduced the final percentage of germination, which becomes completely inhibited at 600 mM NaCl. The adverse effect of salinity is reinforced by high temperatures (30/20 and 35/25 °C). The germination rate was also negatively affected by the increase in salinity and temperature. The final recovery percentages in high salt treatments were near 100%, indicating that exposure to high concentration of NaCl did not inhibit germination permanently.     

Fine-scale spatial genetic structure of Dalbergia nigra (Fabaceae), a threatened and endemic tree of the Brazilian Atlantic Forest

The Atlantic Forest is one of the most diverse ecosystems in the world and considered a hotspot of biodiversity conservation. Dalbergia nigra (Fabaceae) is a tree endemic to the Brazilian Atlantic Forest, and has become threatened due to overexploitation of its valuable timber. In the present study, we analyzed the genetic diversity and fine-scale spatial genetic structure of D. nigra in an area of primary forest of a large reserve. All adult individuals (N = 112) were sampled in a 9.3 ha plot, and genotyped for microsatellite loci. Our results indicated high diversity with a mean of 8.6 alleles per locus, and expected heterozygosity equal to 0.74. The co-ancestry coefficients were significant for distances among trees up to 80 m. The Sp value was equal to 0.017 and indirect estimates of gene dispersal distances ranged from 89 to 144 m. No strong evidence of bottleneck or effects of human-disturbance was found. This study highlights that long-term efforts to protect a large area of Atlantic Forest have been effective towards maintaining the genetic diversity of D. nigra. The results of this study are important towards providing a guide for seed collection for ex-situ conservation and reforestation programmes of this threatened species.     

Distribution patterns and habitat associations of Sandelia bainsii (Teleostei: Anabantidae), a highly threatened narrow-range endemic freshwater fish

Sandelia bainsii is a range-restricted and highly threatened freshwater fish endemic to South Africa. Recent genetic evidence suggests that this species comprises three allopatrically distributed lineages that have been informally designated as Sandelia sp. “Kowie,” Sandelia sp. “Keiskamma” and Sandelia sp. “Buffalo.” As these lineages have only been recently identified and are likely to face a high risk of extinction because of restricted distributions, there is a critical need for generating ecological information to guide conservation prioritisation. The present study compared the historical and current distribution patterns, together with the habitat associations of Sandelia sp. “Kowie” in the Koonap and Kat rivers, tributaries of the Great Fish River. This study indicated that this lineage has been extirpated from one of the three localities in the Koonap River where it was historically abundant. In the Kat River, the current distribution of Sandelia sp. “Kowie” was comparable to its historical range, but its future persistence is threatened by the presence of non-native piscivores, instream physical barriers and potential future exploration for shale gas and infrastructure development in the Karoo Basin. A generalised hurdle negative binomial model revealed that although this lineage's probability of occurrence was high in habitats with boulder and sand substrates, and low conductivity, habitat characteristics were poor predictors of its abundance. Thus, it was postulated that the current range of this lineage probably represents the only available habitats for the persistence of different life stages for this taxon. Alternatively, the observed patterns may suggest the possibility of a shift in habitat associations, possibly for optimum utilisation of the remaining refugia within this river system. Immediate conservation measures should focus on preventing the spread on non-native invasive fishes, whereas future studies should evaluate the impacts of population fragmentation and identify appropriate intervention measures to maintain this lineage's long-term adaptive potential.     

Phylogeographical structure in the coastal species Senecio rodriguezii (Asteraceae), a narrowly distributed endemic Mediterranean plant

Aim Our goals were (1) to assess the levels of chloroplast DNA variation in a narrowly distributed plant restricted to continental islands, (2) to ascertain whether a phylogeographical structure is present in plants restricted to coastal linear systems, and (3) to interpret the results in the light of the known palaeogeography of these islands. Location The Eastern Balearic Islands (Majorca and Minorca) in the Western Mediterranean Basin. Methods Sampling included 134 individuals from 28 populations of Senecio rodriguezii covering the entire range of the species. Sequences of the chloroplast genome (trnT–trnL spacer) were obtained and parameters of population genetic diversity and substructure were determined (h_sh_t, G_st). The geographical structure of genetic variation was assessed by an analysis of molecular variance (AMOVA). Additionally, a spatial AMOVA (SAMOVA) was used to identify groups of populations that were geographically homogeneous and maximally differentiated from each other. Finally, a pattern of isolation by distance was assessed by testing the correlation between the matrix of pairwise Φ_ST values and the matrix of geographical distances between pairs of populations using a Mantel test. Results Seven haplotypes were detected in S. rodriguezii. Only two of them were shared between islands; all of the others were restricted to Majorca (two) or Minorca (three). Overall, we found high levels of genetic diversity and significant geographical structuring of cpDNA markers. Most of the variation detected can be attributed to differences among populations (84.6%), but there was also a significant differentiation between the islands. Main conclusions Our results support the view that the Balearic Islands constitute a reservoir of genetic diversity, not only for widespread Mediterranean taxa, but also for endemic ones. The intraspecific genetic structure found in S. rodriguezii suggests that its population history was dominated by both expansion and contraction events. This has resulted in a species that is highly structured genetically, showing very few shared haplotypes between islands, and a high number of haplotypes restricted to small geographical areas within the islands. Changes in habitat availability and dynamic processes of population fragmentation and connectivity due to repeated cycles of sea‐level changes during the Quaternary are the possible underlying factors that have shaped the cpDNA pool of this endemic species on a regional scale.     

Diet of the thin-spined porcupine (Chaetomys subspinosus), an Atlantic forest endemic threatened with extinction in southeastern Brazil

Chaetomys is a poorly known, monotypic genus of tree porcupine threatened with extinction due to deforestation and habitat fragmentation. Its nocturnal habit, relatively restricted distribution and low level of activity have conspired for decades against detailed field studies. Here the diet of the species in restinga forests is described for the first time. Restinga is a subtype of lowland Atlantic forest occurring on sandy soils close to the Atlantic littoral in Brazil. Three radio-collared females were monitored for 12 months between March 2005 and February 2006. Leaves were the most heavily consumed dietary item, varying from 71.9% to 75.4% of the diet of each individual, followed by flowers (7.7% - 15.7%) and fruits (0 - 1.4%). Animals fed on 57 trees from 14 species, with a higher concentration on Pera glabrata (49.8%) and Tapiriria guianensis (22.7%). Pera glabrata is locally abundant and widely distributed in the Atlantic forest. Each individual consumed a smaller subset of plant species (4-10 species/individual) and shared only the two most important tree species (P. glabrata and T. guianensis). Results corroborate previous studies indicating that Chaetomys is a folivore, perhaps the most folivorous amongst the Erethizontidae. Since the most consumed plant species are relatively common and widespread, Chaetomys might thrive in a broader range of habitats than previously suspected, including secondary forests.     

in vitro propagation of Ochreinauclea missionis (Wall. EX G. Don), an ethnomedicinal endemic and threatened tree

Summary Biotechnology has offered a nonconventional method of plant propagation and has been intensively applied as a conservation strategy for sustaining biodiversity for rare plants. In vitro conservation through micropropagation of Ochreinauclea missionis, a rare, endemic and medicinal tree species of Western Ghats in Karnataka region of India is reported. Multiple shoots were initiated from nodal explants on Murashige and Skoog (MS) medium supplemented with 8.8 μM 6-benzylaminopurine (BA) and 0.3% (w/v) activated charcoal. Shoots were elongated in MS medium with a combination of 2.2 μM BA and 5.3 μM α-naphthaleneacetic acid (NAA) or growth regulator-free medium. Individual shoots with a minimum of one node were excised and rooted in vitro on MS medium with 0.3% activated charcoal or ex vitro rooted by treatment with 49 μM indole-3-butyric acid (IBA) for 30 min. Regenerants acclimated in Soil-rite exhibited 65% survival in the greenhouse.     

Translocation of Otostegia bucharica,a highly threatened narrowly distributed relict shrub

Translocation is a recognized means of rescuing imperiled species but the evidence for the long-term success of translocations is limited. We report the successful translocation of reproductive individuals of a critically endangered shrub Otostegia bucharica from a site facing imminent habitat destruction into a nearby natural population of the species. The relocated plants were visited the year after planting and 13 years later to assess short-and long-term plant survival. Significant percentage of plants that survived transplanting shock and very dry spring following transplanting(around 36%), and further decrease of this number in the next 12 years by only 14%, indicated that O. bucharica is amenable to translocation using reproductive plants. Based on results of species distribution modeling, and failed attempts of ex situ cultivation, we propose introduction of this species into areas with suitable climatic and soil conditions.However, because there is currently no nature reserve in Uzbekistan having suitable conditions for the species under the present climate and that expected in the near future, and because all known habitats of O. bucharica are exposed to the very strong anthropogenic pressure, establishment of a new protected area, awareness building and involvement of local community in conservation activities are required to prevent extinction of this extremely rare species.     

中国特有两栖类受胁现状分析

中国拥有丰富的两栖类资源,共321种,其中特有种236种,这些特有种是我国生物资源独特而重要的组成部分.但受人为和自然等因素的影响,中国特有两栖类出现了较快的种群数量下降,部分物种已经面临濒危状况而很少被人们关注.本文将对中国特有两栖类的数量、分布、受胁原因作简要阐述,以制定相应的保护对策.     

Habitat restriction in Mammillaria pectinifera,a threatened endemic Mexican cactus

Abstract. This study deals with the habitat restriction of Mammillaria pectinifera, a threatened cactus species, confined to a few low density localities of the Tehuacán valley in tropical Mexico. We analysed the patterns of presence/absence of M. pectinifera in relation to the presence/absence of 48 other plant species, and the variation of environmental factors in 120 sampling plots. A Principal Components Analysis revealed a clear segregation between plots with and without individuals of M. pectinifera. A classification analysis resulted in four groups: two with low prevalence and two with high prevalence of M. pectinifera. Paired comparisons between plots with and without M. pectinifera allowed the characterization of its patterns of occurrence related to the variation of environmental factors. M. pectinifera was found on deep alkaline soils with relatively high surface stoniness and high water retention capacity, showing low species richness compared with plots where it was absent. The limited distribution of M. pectinifera in the Tehuacán Valley seems to be related to particular requirements of this species, being restricted to certain suitable habitat patches. Nevertheless, it is likely that other aspects, such as poor dispersal and establishment abilities, or biotic interactions could be associated with the observed patterns.     

Population genetic analysis reveals a long-term decline of a threatened endemic Australian marsupial

Since European colonization, Leadbeater's possum ( Gymnobelideus leadbeateri ) has declined across its range to the point where it is now only patchily distributed within the montane ash forests of the Central Highlands of Victoria. The loss of large hollow-bearing trees coupled with inadequate recruitment of mature ash forest has been predicted to result in a reduction in population size of up to 90% by 2020. Furthermore, bioclimatic analyses have suggested additional reductions in the species' distribution under a variety of climate change scenarios. Using a panel of 15 highly resolving microsatellite markers and mitochondrial control region sequence data, we infer past and present gene flow. Populations in the northern part of the core range were highly admixed, and showed no signs of either current or historical barriers to gene flow. A marginal, isolated and inbred population at Yellingbo was highly genetically differentiated, both in terms of current and historic genetic structure. Sequence data confirmed the conclusions from earlier genetic simulation studies that the Yellingbo population has been isolated from the rest of the species range since before European-induced changes to the montane landscape, and formed part of a larger genetic unit that is now otherwise extinct. Historic loss of maternal lineages in the Central Highlands of Victoria was detected despite signals of immigration, indicating population declines that most probably coincided with changes in climate at the end of the Pleistocene. Given ongoing habitat loss and the recent (February 2009) wildfire in the Central Highlands, we forecast (potentially extensive) demographic declines, in line with predicted range reductions under climate change scenarios.     

Rare and threatened new endemic Ixora (Rubiaceae) from New Caledonia

Ixora clarae and I. elisae (Rubiaceae) are two endemic species described from New Caledonia. Ixora clarae is easily recognised by its (1–)3-flowered inflorescences, made up by thick and large flowers embedded in a calyculus. It is known from a few specimens collected on the nearest mountains by Nouméa, and is considered as endangered (EN). Ixora elisae is remarkable for its very enlarged campanulate calyx-limb. The latter one, from the Isle of Pines and Lifou, known by only two herbarium collections, is probably on its way to disappear in nature. Consequently, it is proposed to be classified as critically endangered (CR).     

Tapeinostemon sessiliflorum (Gentianaceae), a new combination for a Guayana endemic

A new combination,Tapeinostemon sessiliflorum (Gentianaceae), is made forPsychotria sessiliflora (Rubiaceae).Tapeinostemon capitatum is placed into synonymy ofT. sessiliflorum. This rare species occurs in the Guayanan region of Brazil, Colombia, and Venezuela.