On Distributional Features of the Genus Aconitum in Sino-Himalayan Flora

The geographical distribution of Aconitum in the Sino-Himalayan subregion is analysed in the present paper on the basis of taxonomy and relationship between the infrageneric taxa. Asaresult, some conclusions may be arrived as follows: 1. The Sino-Himalayan subregion is the frequency centre and the diversity centre of the genus. For analysis, the distribution area of the genus are assigned to three floristic regions, viz. 1) the East-Asian floristic region, consisting of the Sino-Himalayan subregion and SinoJapanese subregion, 2) the Euro-Siberian region and 3) the North-American region (Table 1). In the East-Asian floristic region, the Sino-Himalayan subregion comprises 3 subgenera, about 5 sections, about 13 series and nearly 180 species. However, the Sino-Japanese subregion has only 2 subgenera, 2 sections. 6 series and about 50 species. The Euro-Siberian region has 2 subgenera, 2 sections, about 9 series and nearly 70 species. The North-American region has 2 subgenera (one of the 2 subgenera has only 1 species), 1 section, 1-2 series and about 26 species. Obviously, the Sino-Himalayan subregion is the richest in taxa. 2. The Sino-Himalayan subregion is not only the preservation centre of the primitive groups and species, but also an actively differentiating region. Largely in the Sino-Himalayan subregion occurs primitive or more primitive tava in the genus, such as Sect. Fletcherum, Sect. Alatosperum and Sect. Sinaconitum, Ser. Tangutica and Ser. Brunnea etc.: A fletcherianum, A. novoluridum, A. chrysotricum, A. brevicalcaratum, A. polycarpus, A. nagarum, A. tanguti cum, A. hookeri, A. naviculare, A. violaceum, etc. On the other hand, the Sino-Himalayan subregion also has the most or relatively advanced taxa, represented by the annual monotypic subgenus Gymnaconitum, A. spiripetalum, A. hamatipetalum and A. bulbitiferum ect. About 50 infraspecific taxa occur in the subregion. For example, A. hemsleyanum has 8 varities, A. franchetii has varities and A. nagarum 1 varity and 2 forms, ect. 3. In the region under discussion the genus Aconitum shows remarkable endemism. The endemic taxa include 3 sections (Sect. Fletcherum, Sect. Alatosperum and Sect. Sina conitum), 3 series (Ser. Brevicalcarata, Ser. Crassiflora and Ser. Bullatifolia) and nearly 150 species, among which primitive and advanced ones are both present. 4. The pattern of geographical distribution of the genus Aconitum shows remarkable relationship between latitude and altitude. The majority of species of this genus prefer habi tats with a cool and more or less constantly moist climate. In the Sino-Japanese subregion, with a higher latitude, the genus has an altitude range of 500-1500 m, whereas in the Sino-Hima-layan subregion the range is 2900-5000 m. To sum up, the Sino-Himalayan subregion is the diversity centre, the frequency centre, the differentiation centre, the preservation centre of the primitive taxa and the centre of endemism of the genus Aconitum, and its development in this subregion has probably been accelerated by the lift of the Himalayas and the complicated environmental conditions.     

Quantitative Analysis of Genera Endemic to China

Chinese flora with many endemic elements is highly important in the world’s flora. According to recent statistics there are about 196 genera of spermatophytes, being 6.5% of total Chinese genera. These endemic genera comprising 377 species belong to 68 families, among which the Gesneriaceae (28 genera), Umbelliferae (13), Compositae (13), Orchidaceae (12) and Labiatae (10) are predominant. The tropical type containing 24 families and 80 genera is dominant. After it follows the temperate type with 23 families and 50 genera. There are also 4 families endemic to China, i.e. Ginkgoaceae, Bretschneideraceae, Eucommiaceae and Davidiaceae. It shows that genera endemic to China are obviously related to the tropical and temperate flora in essence. The endemic monotypic genera (139) and endemic obligotypic genera (48) combined make up more than 95% of the total number of genera endemic to China. Phylogenetically more than half of them are ancient or primitive. The life forms of all endemic genera are also diverse. Herbs, especially perennial herbs, prevail with the proportion of about 62%, and trees and shrubs are the next, with 33%, and the rest are lianas. Based upon the calculated number of genera endemic to China in each province and the similarity coefficents between any two provinces, some conclusions may be drawn as follows: Yunnan and Sichuan Provinces combined are the distribution centre of genera endemic to China and may be their original or differentiation area, because numerous endemic genera, including various groups, exist in these two provinces. The second is Guizhou where there are 62 endemic genera. Others form a declining order, south China, central China and east China. But towards the north China endemic genera decrease gradually, and the Qinling Range is an important distributional limit. The largest simitarity coefficient, over 50%, appears between Shaanxi and Gansu probably because of the Qinling Range linking these two provinces. But between any other two provinces it is less than 30% and it is generaly larger between two south provinces than between two north provinces. These characteristics mentioned above are correlated with topography and climate, and they may be resulted from the diversification in geography and climatic influence for a long time.     

中国壳斗科的地理分布及其与气候条件的关系

壳斗科是温带、亚热带最重要的森林树种之一,在我国有7属350多种和变种,呈北东东—南西西向分布,几乎遍及全国,在亚热带和温带森林中,常成为重要的建群种。壳斗科在我国总体上是北温带—亚热带分布类型。本文对壳斗科的物种丰富度分布、特有性分布及其与气候地理条件的关系进行了研究,并提出种类特有性的指数(EI,Endemic Index)：EI=(N/∑Ki)×10 研究发现,分布的物种丰富度中心在滇、桂、黔一带,而特有性中心则在滇、藏、琼等地。另外,通过逐步回归及比较分析,发现水热状况往往成为限制壳斗科物种丰富度分布格局的主导因子。而海峡等生态、地理隔离因子及空间异质性等对特有性指数的增加有明显的促进作用。影响物种丰富度与特有性指数分布的生态因子往往有较大的差异。     

Comprehensive population viability study of a rare endemic shrub from the high mountain zone of the Canary Islands and its conservation implications

Oceanic island ecosystems harbour many endemic plant and animal species, which are often threatened because they have only a few small populations. Many factors contribute to the biological viability of such populations, such as demography and population dynamics, breeding system and pollination ecology, seed dispersal and genetic variation. In a collaborative project, all these factors were studied in the rare endemic, predominantly monoecious shrub Bencomia exstipulata Svent. (Rosaceae), which grows exclusively in the national parks of El Teide (Tenerife) and La Caldera de Taburiente (La Palma). Demography was monitored through annual censuses of individual plants in a natural and an augmented population on Tenerife. The breeding system and reproductive success were studied through bagging and pollination experiments, and insect visitation censuses. Seed dispersal by animals was assessed using cafetaria experiments. With matrix projection models and stochastic simulations, we show that the Tenerife population was demographically stable. This was largely explainable by the high survival of adult individuals. Despite frequent germination, successful seedling recruitment was very rare. Male and female flowers occurred in separate inflorescences within individuals, although some inflorescences were mixed and some shrubs were entirely male or female. Despite frequent visits by honeybees, the species is predominantly wind pollinated. Insect-proof bags reduced seed set by 12.5%, and pollen-proof bags by 44%. Large quantities of airborne pollen were detected on unbagged sticky microscope slides, this was 56% reduced by insect-proof and 96% by pollen-proof bags. Hence, some self-pollination also seems to occur. Cafetaria experiments showed that the local lizards (Gallotia galloti Oudart) readily eat the fruits and that the seeds pass through their intestines unharmed and germinable. Since other dispersal vectors are unknown, saurochory seems the most likely mode of dispersal. Our study strongly suggests that the population of B. exstipulata on Tenerife is viable, and that there are no significant threats associated with its breeding system, pollination or seed dispersal. To alleviate the natural extinction risk typical of narrow endemics, five main conservation measures are proposed.     

Mutational signature of aristolochic acid: Clue to the recognition of a global disease

Mutational signatures associated with specific forms of DNA damage have been identified in several forms of human cancer. Such signatures provide information regarding mechanisms of tumor induction which, in turn, can reduce exposure to carcinogens by shaping public health policy. Using a molecular epidemiologic approach that takes advantage of recent advances in genome sequencing while applying sensitive and specific analytical methods to characterize DNA damage, it has become increasingly possible to establish causative linkages between certain environmental mutagens and disease risk. In this perspective, we use aristolochic acid, a human carcinogen and nephrotoxin found in Aristolochia herbs, to illustrate the power and effectiveness of this multidisciplinary approach. The genome-wide mutational signature for this toxin, detected initially in cancers of the upper urinary tract, has subsequently been associated with cancers of the liver and kidney. These findings have significant implications for global public health, especially in China, where millions of individuals have used Aristolochia herbal remedies as part of traditional Chinese medicine and, thus, are at risk of developing aristolochic acid nephropathy and/or upper urinary tract carcinomas. The studies reported here set the stage for research into prevention and early detection, both of which will be required to manage a potentially devastating global disease.     

Human Land use Threatens Endemic Wetland Species: The Case of Chorthippus lacustris (La Greca and Messina 1975) (Orthoptera: Acrididae) in Epirus, Greece

Chorthippus lacustris is an endemic grasshopper (Orthoptera) species in Epirus, Greece. Its population status, habitat characteristics, and relation to historical and current human land use are investigated. The species has a restricted and fragmented distribution pattern. Five locations, four within Pamvotida Lake basin and one in Lake Paramythia, cover a total of 0.12 km². It is strongly dependent on wet grasslands, flooded on a seasonal basis. The greatest population density is recorded in the site with the greatest diversity of dominant plant species. Ch. lacustris is estimated to have lost 85–99% of its habitat during the last 50 years due to wetland drainage. The main threat to the species survival is further habitat loss by urbanisation around Pamvotida Lake and by land conversion to agriculture in Paramythia Lake, even though both sites belong to the Natura 2000 network. The species status is Critically Endangered and it should be listed in Annex II of the Habitat Directive (92/43/EEC) as a priority species for conservation. Restoring wet grasslands, protecting them from further urbanisation and drainage, and monitoring species population are the main measures proposed for its conservation.     

From seed to seedling: A critical transitional stage for the Mediterranean psammophilous species Dianthus morisianus (Caryophyllaceae)

Abstract

Seed germination, seedling emergence and seed persistence in the soil were investigated for Dianthus morisianus (Caryophyllaceae), a psammophilous endemic species of Sardinia. Stored and freshly collected seeds were incubated in a range of constant temperatures (5–25°C) and an alternating temperature regime (25/10°C). The effect of seed burial depth on seedling emergence was investigated under controlled environmental conditions. Seed persistence in the soil was verified by in situ experimental seed burials. Seeds of this species were non-dormant, and all seed lots germinated both in the light and darkness, mainly at low temperatures (≤20°C), with a maximum at 15°C (≥95%). Optimal seedling emergence was obtained when seeds were buried at a depth of 1–2 cm, and a declining emergence with increasing depth was observed. D. morisianus was also unable to form a persistent soil seed bank. The fate of the seeds that, after dispersal, do not emerge from the soil in the spring is, therefore, presumably to die before the next favourable growing season.     

Alcuni aspetti della biologia della riproduzione del genere Limonium

“The New Red List of the Italian Flora” includes all the Italian policy species and other species of known conservation concerns for a total of 400 taxa, 65% of which are threatened with extinction. The Red List is based on a huge georeferenced data-set useful for conservation purposes.     

Assessing the conservation status of the strict endemic Desertas wolf spider,Hogna ingens (Araneae,Lycosidae)

The Desertas Islands (Madeira, Portugal) are the sole home of one of the largest and rarest wolf spider species, Hogna ingens (Blackwall 1857) (Araneae, Lycosidae). Despite its size, it inhabits a single valley in the North of the Deserta Grande Island, Vale da Castanheira, currently invaded by the herb Phalaris aquatica. This invasive species competes with the native flora and was subject to several eradication experiments, namely through fire and chemicals. The objectives of this work were to: (1) estimate the current distribution and abundance of H. ingens and respective trends; (2) evaluate the impact of the invasive plant and eradication methods on the spider population; (3) suggest future measures for the recovery of the species; and (4) evaluate its conservation status according to the IUCN criteria.The current distribution of H. ingens covers 23 ha, a recent reduction from its original 83 ha, corresponding to the entire Vale da Castanheira. A total of 4447 and 4086 adults and 71,832 and 24,635 juveniles were estimated to live in the valley during 2011 and 2012, respectively. We found a significant negative impact of P. aquatica cover on the presence and abundance of H. ingens and that chemical treatment specifically directed towards the invasive plant species may be the only way to effectively recover the spider's habitat. We suggest (1) regular monitoring; (2) extend chemical treatments; (3) ex-situ conservation with future reintroduction of adults. Based on the current area of occupancy (AOO) of H. ingens and its recent decline in both AOO and number of individuals, it was recently classified as Critically Endangered by IUCN and we suggest its urgent inclusion in the Habitats Directive species lists.