Number Of Mature Individuals Research Articles

Population age structure and conservation status of Ferula sinkiangensis (Apiaceae) in Xinjiang, China

Abstract Ferula sinkiangensis K.M. Shen is a threatened medicinal plant endemic to Xinjiang, China, with a small population size and a narrow distribution range. We assessed the status of this species with respect to its population age structure, the level of threat and extinction risk. Only one population remains, in Yining County, Xinjiang. We conducted field surveys of the population in 2022 and 2023, counting 2,033 and 1,515 individuals, respectively, in 144 sample quadrats. We assessed the age structure of the population by counting the number of basal leaves of each individual. The frequency distribution had an inverted J-shape, indicative of a relatively stable age structure. However, the number of mature individuals was small, raising concerns about the risk of genetic drift and inbreeding. This species is also threatened by habitat destruction and inappropriate collection practices. We recommend that F. sinkiangensis is categorized as Critically Endangered on the IUCN Red List on the basis of criteria B2ab(iii), C2a(i) and D.

The recently discovered Principe Scops-owl is highly threatened: distribution, habitat associations, and population estimates

SummarySpecies baseline information is required for effective biodiversity conservation. Here we provide sound ecological data to support effective conservation of the Principe Scops-owl,OtusbikegilaMelo, Freitas, Verbelen, Costa, Pereira, Fuchs, Sangster, Correia, de Lima & Crottini 2022, discovered in 2016. We mapped the observed and potential distribution, inferred habitat associations, estimated population size, and assessed the International Union for Conservation of Nature (IUCN) Red List category for this species. Surveys were carried out across Príncipe Island during the long and short dry seasons, recording owl presence in sampling points along transects. These data were used to model distribution, revealing that the Principe Scops-owl is restricted to 34.4 km2in the south of the island, inside the Príncipe Obô Natural Park. Most records were in lower altitude native forest. Remoteness was the most important variable to explain presence at island level, followed by land use, which showed that the species is restricted to forest, clearly depending on native forest. Distance sampling using different models suggested a population density ranging between 33.4 individuals/km2(95% CI: 23.6–47.2) and 46.4 individuals/km2(95% CI: 29.3–73.6), which extrapolates to an estimated population size ranging from 1,149 individuals (95% CI: 813–1,623) to 1,597 individuals (95% CI: 1,007–2,533). We propose that the species is classified as “Critically Endangered” due to the small extent of occurrence, coupled with occurrence in a single location and inferred continuing declines in the extent of occurrence, area of occupancy, number of mature individuals and area, extent, and quality of habitat. Effective conservation of the Principe Scops-owl requires regular monitoring and further studies focusing on reproduction and potential nest predation by introduced mammals. Widespread support for the conservation of the Natural Park is vital to ensure the protection of this species and the endemic-rich native forests of Príncipe on which it depends.

Reproductive biology of the Gorgona guitarfish Pseudobatos prahli in the central-eastern Pacific Ocean

Pseudobatos prahli is considered a low-medium fishing importance species in Ecuador, caught as target species and bycatch in both artisanal and industrial fisheries. Despite its importance, some basic aspects of its biology remain unknown, turning its study a priority. The aim of the present research was to describe for the first time the reproductive biology of P. prahli based on the analysis of individuals landed in the port of Santa Rosa, Province of Santa Elena, Ecuador. A total of 96 females and 165 males were sampled from January 2013 to January 2014. Females presented larger sizes (51-86 cm total length, TL) than males (51-78 cm TL), but no significant differences were found between the mean sizes of both sexes. The sexual proportion of landed individuals (0.6F:1M) suggested that free-living individuals segregate by sex, however, sex proportion of embryos was similar to the proportion 1F:1M. The number of mature individuals (64%) in the landings was larger than the immature ones (36%). Mean size at maturity (L50) of females (65.9 cm TL) was also slightly larger than that for males (61.8 cm TL). Size at birth was estimated at 22.5 cm TL. Ovarian fecundity ranged from 1 to10 and uterine fecundity from 1 to 6, and a positive but low linear relationship was found between both fecundity estimates and maternal size. Based on the comparison of some reproductive parameters, such as mean size at maturity, gestation period and fecundity, it can be concluded that P. prahli is one of the species with lowest biological productivity among the species of the same genus.

Evaluation of ongoing Crested Ibis (Nipponia nippon) reintroduction using an integrated population model and Bayesian population viability analysis

Reintroduction has often been used as a technique for re‐establishing self‐sustaining animal populations that have become extinct within their indigenous range. To achieve conservation success, it is essential to accurately assess the demographic parameters and the IUCN Red List criteria of the population. However, acquiring data on all indicators and estimating criteria according to established definitions can be challenging. Here, we developed an integrated population model (IPM) and population viability analysis (PVA) framework to estimate all demographic parameters and criteria for a reintroduced population of Crested IbisNipponia nippon, and to project population dynamics under a range of release scenarios on Sado Island, Japan. Our IPM‐PVA framework integrated roost count and mark–resight data for 415 released and 203 wild‐hatched individuals, as well as reproductive performance for a total of 575 pairs. We aimed to assess survival, reproductive success, population size, number of mature individuals and population projection. In the first year after release, the estimated apparent annual survival rate was 0.566 [Bayesian credible intervals (CRI) 0.518–0.614]; however, this rate increased after 1 year (0.865; CRI 0.836–0.892). Wild‐hatched juveniles exhibited a high survival rate (0.757; CRI 0.670–0.838) that was just lower than that of adults (0.899; CRI 0.844–0.949). The reproductive success rate varied with pair attributes (released–released pair: 0.245, CRI 0.194–0.299; released–wild pair: 0.377, CRI 0.281–0.471; wild–wild pair: 0.350, CRI 0.237–0.471). Total population size was estimated to be 457 individuals (CRI 384–525), with 261 mature individuals (CRI 211–304) in June 2021. The probability of Crested Ibis extinction in the next five generations was 0%, even if the release was discontinued. Our comprehensive case study demonstrated the effectiveness of IPM‐PVA for the evaluation of ongoing reintroduction programmes.

Range extension and conservation status of the rare Solanaceae shrub, Solanum conocarpum.

BackgroundThe British Virgin Islands and the US Virgin Islands, two island groups located in the Caribbean archipelago, hold unique plant diversity and high endemism. Until recently, Solanumconocarpum was considered a rare plant species endemic to the island of St. John in the US Virgin Islands. Ongoing botanical surveys in this region are revealing new populations and refining our understanding of the distribution of these narrow endemic plant species. The objective of this paper is to assess the conservation status of S.conocarpum, including a review of its geographic range, population numbers, threats and conservation actions needed for its long-term survival.New informationIn this paper, we present new occurrences for S.conocarpum, extending its geographic range to a new island, Tortola and new territory, the British Virgin Islands. Despite this range expansion, this species is evaluated as Endangered (EN), based on Criteria B1b(iii,v)+2b(iii,v)+C2a(i), according to the IUCN Red List Categories and Criteria. The extent of occurrence (EOO = 46 km2) and area of occupancy (AOO = 20 km2) are highly restricted. On St. John (US Virgin Islands), the historically recorded individuals at Reef Bay, Europa Ridge and Sabbat Point are now considered extirpated due to disturbance from development compounded by invasive species, as well as the impact of feral ungulates and drought stress. These threats are impacting the species across the whole island of St. John and contributing to a continuing decline of suitable habitat, despite the island being a National Park. On the island of Tortola, the species occurs on unprotected lands subject to development and habitat modification and decline by feral ungulates. Based on these threats acting separately across the two islands, two locations were defined. The estimated total number of mature individuals ranges between 150 and 250, with the largest subpopulation at Nanny Point in the US Virgin Islands, containing 108 mature individuals. Conservation action, focused on protecting this species' habitat, is urgently needed.

Biology and ecology of sea catfish (Ariidae) of estuarine, lagoon and coastal ecosystems in West Africa.

The family Ariidae, sea catfish of the order Siluriformes, is widely distributed throughout the world, particularly in tropical and subtropical areas. The three species of Ariidae found on the coasts and estuaries of West Africa are the smoothmouth catfish Carlarius heudelotii (Valenciennes 1840), the rough-head catfish Carlarius latiscutatus (Günther 1864) and the Guinean sea catfish Carlarius parkii (Günther 1864). They have been increasingly exploited by artisanal and industrial coastal fisheries in recent decades, but there is still little information available on their ecology and biology. The aim of this study was to deepen our knowledge of these three West African Ariidae species based on a dataset collected between 1980 and 2013 during experimental fishing programmes. They were carried out in Mauritania in the Banc d'Arguin National Park, in Senegal in the Sine Saloum estuary including the Bamboung Marine Protected Area (MPA), in The Gambia in the Gambia estuary, in Guinea-Bissau in the Urok Islands MPA in the Bijagos archipelago, in Guinea in the Fatala estuary and Dangara inlet, and in Côte d'Ivoire in the Ebrié Lagoon. C. latiscutatus accounted for 65%, C. parkii for 29% and C. heudelotii for 6% of total number of Ariidae sampled. C. latiscutatus was abundant in the Sine Saloum and Gambia estuaries as well as in Guinea and Guinea-Bissau and was the only species present in the Ebrié Lagoon. C. parkii was in the majority in Mauritania. The three species were recorded in a salinity range of 0 to 50, a temperature range of 19 to 34°C, in areas 1.7 to 15 m depth, and transparency ranging from 0.1 to 4m (Secchi disk depth). C. heudelotii was present in less saline (25 vs. 32-34), less warm (27 vs. 29°C) and less transparent (0.8m vs. 1.6 m) waters than the two other species. The maximum sizes (453 mm, 614 mm and 525 mm for, respectively, C. heudelotii, C. latiscutatus and C. parkii) were comparable to those recorded at sea. Length-weight relationships calculated for each species showed b coefficients greater than 3. Sex ratios were always in favour of females. The number of mature individuals and their smallest size at maturity were calculated per species, sex and study area. A size of 27-28 cm at first maturity was estimated for females of C. latiscutatus. A few dozen records made it possible to describe fecundity and cases of oral incubation by females. The diet of the three species was composed of crustaceans, fish and molluscs, confirming their classification as generalist predators. Thanks to their high environmental tolerance, these sea catfish populations are able to occupy both the continental shelf and adjacent estuaries throughout their life cycle, with the exception of spawning, which generally takes place at sea.

Ecological features and traditional knowledge of Roscoea alpina Royle a medicinal plant in Himalaya

Roscoea alpina Royle (Zingiberaceae) commonly known as Kakoli is a perennial medicinal herb endemic to the Himalayas. It is used in vitality strengthening Ayurveda groups i.e., Astavarga and Jeevaniyagana and in preparation of Ayurvedic formulations e.g., Chyavanprasha and Divya Pidantak Tail . Considering its medicinal uses, high demand and overexploitation, natural habitats were surveyed in subalpine and alpine regions of Garhwal Himalayas for population estimation and to identify elite germplasm. R. alpina frequency was recorded more than 60 % in Tungnath, Dayara, Valley of Flowers and Kedarnath populations. However, plant density and area occupied were low compared to other species of subalpine and alpine region. For threat category assessment, IUCN Red List Categories and criteria were used and conservation status was assigned, based on site to site and for entire Garhwal region of the Western Himalaya. R. alpina , based on extent of occurrence was categorized as Vulnerable and based on number of mature individuals as Endangered for the Garhwal Himalaya. Further, habitat destruction and degradation were the major threats for population reduction in the wild. Morphological variation revealed plants from Tungnath and Kedarnath may be used for future propagation and domestication efforts.

Adjustments in population and reproductive dynamics of native and non-native congeneric species during 26 years after invasion

ABSTRACT We aimed to improve the understanding of the establishment of Serrasalmus marginatus (non-native), which was followed by a decrease in the abundance of Serrasalmus maculatus (native) in the upper Paraná River floodplain. We estimated age, mortality rate, length and age at first maturity and variations in gonad development in three time-periods along a 26-year truncated time scale for both species. Population and reproduction parameters of both species showed substantial fluctuations among periods. Most age classes were sampled in all time-periods, but with considerable difference in abundance, with predominance of older individuals in the second time-period and younger individuals in the third time-period for both species. The mortality rates decreased for both species in the second time-period, but increased for the native in the third time-period. Length and age at first maturity decreased in the second time-period for both species, increasing the number of mature individuals on their populations. In the third time-period, the number of immature individuals increased for both species. We suggest that species experienced stressful conditions during cooccurrence and this have resulted in physiological responses in both species, reflecting in population and reproductive adjustments that may have relaxed competitive interactions between them, optimizing survival, reproductive effort and coexistence.

Assessing the conservation status of tree fern Cibotium arachnoideum (C. Chr.) Holttum

Abstract. Praptosuwiryo TN. 2020. Assessing the conservation status of tree fern Cibotium arachnoideum (C.Chr.) Holttum. Biodiversitas 21: 1379-1384. Cibotium arachnoideum (C.Chr.) Holttum (Cibotiaceae), is a large terrestrial fern with an upright or prostrate rhizome having densely shining reddish-brown of rigid hairs and one or two pairs of sori with two indusia forming a small cup on each lamina-segment. This tree fern is a rare species and strictly distributed in the Malesian region. The study aims to assess the conservation status of C. arachnoideum by using the 2012 IUCN Red List Catagories and Criteria (version 3.1.). Population size was estimated and observed both based on specimens deposited at the Herbarium Bogoriense (BO) and field studies in Sumatra. The area of occupancy (AOO) of this species is 44 km2. Cibotium arachnoideum is occurred in severely fragmented locations in the West Malesian region, in 2 locations, viz. Sumatra and Borneo. Sumatra has only two subpopulations, and Borneo has nine subpopulations. The number of mature individuals was only found 372 in one location of North Sumatra and 19 individuals in one location of Bengkulu. Therefore, C. arachnoideum is proposed as an endangered species, En: B2ab (i,ii,iii) + C2a (ii).

Variability of morphological and anatomical characteristics of Serbian spruce (Picea omorika /Panc./ Purkyne) needles of natural population located in the Milesevka river canyon

Serbian spruce (Picea omorika /Panc./ Purkyne) is rare and endangered tertiary relict and endemic species in the Balkan Peninsula. Its natural distribution is fragmented and restricted to western Serbia and eastern Bosnia and Herzegovina, mainly in the canyon of middle course of the Drina river. Since the mid-19th century, the number and size of populations have been steadily decreasing accompanied by a decline in the number of mature individuals, endangering natural regeneration is endangered. The objective of this study is to determine variability within Serbian spruce (Picea omorika /Panc./ Purkyne) natural population in the canyon of the Milesevka river on the basis of morphological and anatomical characteristics of needles and, thus, to broaden knowledge on this rare and endangered species. Twigs with needles collected from all mature individuals that represent the population were used as material for the study. The following morphological and anatomical characteristics were measured: NL- needle length; NH - needle height; NW - needle width; CT+EH - cuticle + epidermis height; HH - hypodermis height; VB - vascular bundle diameter; No of SC - number of resin channels; SC diameter - resin channel diameter. The average values of the measured characteristics are: needle length 13.23 mm; needle width 1239.93 ?m; needle height 608.63 ?m; cuticle + epidermis height 11.49; hypodermis height 17.59 ?m; vascular bundle diameter 220.64 ?m; number of resin channels 0.74; resin channel diameter 52.36 ?m. The characteristics with the highest variability are as follows: number of resin channels (161.64%); resin channel diameter (25.35%); hypodermis height (20.79%), while the needle width is a characteristic with the lowest variability (6.39%). The results of the analysis of variance showed very high statistical differences within population for all studied characteristics (p<0.01; ?=0.05). In order to make the results clearer, it is necessary to investigate the genetic diversity and population structure by analyzing various phenotypic characteristics in specially designed experiments (e.g. progeny tests) as well as by analyzing appropriate DNA markers. The studied population must be involved in continuous conservation and breeding processes, especially through appropriate forms of ex situ conservation.

<p class="Body">Seasonal changes in populations of sheep tick, Ixodes ricinus (L., 1758) (Acari: Ixodinae) in natural biotopes of St. Petersburg and Leningrad province, Russian Federation

Changes in the seasonal activity and age composition of adults and nymphs in populations of the Ixodes ricinus in northwestern Russia have been studied. Adult ticks and nymphs were collected on flag twice a month from April to October in 2014–2016. They were investigated for biological age (light-optical preparations of the midgut after staining fat with Sudan III). DNA isolated from ticks was analyzed using real-time PCR (fluorescent probe technology) for the presence of Borrelia burgdorferi s.l. pathogens based on amplification of the 16SrRNA and Hbb gene fragments. The season of activity of the adults shows one peak, the largest numbers show up in July–August (September). The population of adults is composed of two generations. The first generation is active from the beginning of the season until nearly its end, mid-October. Until the end of June, young individuals with large fat reserves predominate in the population. From July to the end of September, the adult population is formed mainly of mature individuals. Older individuals in the population appear from mid-July, and become dominating only in August and, mainly, in September. Ticks of the second generation, as young individuals, were recorded from the end of August until the end of the season of activity. The active nymphs were captured from late April until late October. The season of activity of nymphs begins and ends with a 100% content of young individuals. The spring population (April–May) consists of young nymphs, in June the proportions of young and mature are equalized, in July and August the ratio of mature and old nymphs is balanced, in September old individuals prevail, which were not found in October. The first generation is the nymphs who have hatched from August to October during the previous season, and the second one is the nymphs hatching in August of the current year. The lifespan of adults and nymphs can reach 13–15 months. The proportion of infected ticks in May and June is 24.5% and 25%, with the highest rates of in the young (10–12 months) part of population (70–85% of individuals). In July, the number of mature (12–13 months) individuals increases (up to 75–95%), at the same time the average values of infection fall to 20.8%. In August, the shares of mature (45–55%) and old -13–15 months (45–55%) individuals are approximately balanced. Borrelia contamination is also decreasing (14.3%). In September, the number of mature individuals (29.7%) was about 2 times lower than the old ones (65.3%), and the infection rate decreased to 11.4%. The population of nymphs and adults is composed of two tick generations in the season of activity. The season of activity of adult ticks is holistic; it is not interrupted during the summer months. Infection of adults with Borrelia decreases simultaneously with the ageing of the population.

Species conservation profiles of cave-dwelling arthropods from Azores, Portugal.

BackgroundAzorean volcanic cave biodiversity is under considerable pressure due to ongoing threats of pollution, land use change, touristic activities or climate change. In this contribution, we present the IUCN Red List profiles of 15 cave-adapted arthropod species, endemic to the Azorean archipelago, including species belonging to the speciose genus Trechus (Carabidae), which is represented in Azores by seven species. The objective of this paper is to assess all endemic Azorean cave-adapted species and advise on possible future research and conservation actions critical for the long-term survival of the most endangered species.New informationMost species have a restricted distribution (i.e. occur in one or two caves), very small extent of occurrence (EOO) and a small area of occupancy (AOO). A continuing decline in the number of mature individuals is inferred from the ongoing cave habitat degradation. The two troglobitic species of the homopteran genus Cixius are in great danger of extinction due to major land-use changes in epigean habitats above their known localities. We suggest, as future measures of conservation, the regular monitoring of the species (every five years), the creation of additional protected caves, the limitation of several aggressive activities around the caves (e.g. decreasing pasture intensification) and in some cases the creation of fences in the entrance of the most important caves.

Perrottetiawichmaniorum (Dipentodontaceae), a new species from Kaua'i, Hawaiian Islands.

Perrottetiawichmaniorum Lorence & W. L. Wagner, sp. nov. is described as endemic to Kaua‘i. It differs from its Hawaiian congener P.sandwicensis by its larger, thicker, more densely hirtellous-villosulous rugose leaves with a smaller length:width ratio [1.5–1.7:1], larger inflorescences with usually four degrees of branching with moderately to densely hirtellous axes, and flowers with glabrous petals. This new species falls into the Endangered (EN) category when evaluated using the IUCN Red List criteria for endangerment based on its small area of occupancy, a decline in the extent and quality of its habitat, and number of mature individuals.

¿Es Oncidium poikilostalix una especie invasora? Ecología poblacional y comportamiento reproductivo de esta orquídea epífita en Chiapas, México

Antecedentes y Objetivos: Las invasiones biológicas se consideran la segunda causa de extinción de especies después de la destrucción del hábitat. Cuando se trabaja con especies con una tendencia expansiva, los estudios de dinámica poblacional son particularmente relevantes. Los objetivos de este estudio fueron: (1) evaluar la ecología poblacional de Oncidium poikilostalix en cafetales de sombra en México, (2) evaluar el comportamiento reproductivo de O. poikilostalix en este hábitat, y (3) determinar si esta orquídea se debe considerar como una especie invasora.Métodos: Durante 2013-2015 se marcaron y midieron la mayoría de los individuos de la población mexicana de O. poikilostalix (localizada al sur del estado de Chiapas). Además, se registraron anualmente la producción de flores y frutos (primera floración y floración repetida), la mortalidad y el reclutamiento de nuevos individuos, y se modeló su distribución potencial.Resultados clave: Dentro de este periodo se observó un incremento poblacional de 1.11%, con un aumento proporcional en el número de flores y frutos. Existe una fuerte correlación entre el área foliar de los individuos, y la producción de espigas (R=0.690, p<0.001) y flores (R=0.775, p<0.001). El número de individuos adultos que tuvieron floración repetida varió de 47.1% en 2013 a 22.5% en 2015. También se encontró correlación entre el área foliar de los individuos y el hecho de que no florezcan, florezcan una vez, o presenten floración repetida (X2=277.65, p<0.001). La población mexicana de O. poikilostalix se localiza en el límite norte de la distribución potencial de esta especie.Conclusiones: Es poco probable que O. poikilostalix sea una especie invasora. A pesar de ser un taxon localmente abundante, con una población aparentemente sana establecida en cafetales tradicionales de sombra, su área de distribución en México aún es restringida, lo que puede representar un grave riesgo para su supervivencia en el país.

<b>Distribution and population status of <I>Kingiodendron pinnatum</I> (Angiosperms: Fabaceae) an endemic and endangered legume tree in southern Western Ghats, Kerala, India</b>

An extensive survey and population analysis of the endemic and endangered tree Kingiodendron pinnatum, was carried out in the Kerala area of the Western Ghats. The aim was to assess the pattern of distribution, population size and natural regeneration of the species. The fragmented and patchy populations of the species are distributed in evergreen/semi evergreen habitats within an altitudinal range of 176-680m elevation. The tree attained a first layer/canopy species with a height range from 24–30m. Altogether 17 populations were identified and mapped in 13 forest locations in the region. A total of 140 adult individuals of the species were enumerated within the 13 forest locations. Natural regeneration of the species recorded from three zones among the 13 forest locations covering 21,000m2 area representing the Kerala state. The flowering trees displayed a height and dbh range of 10-30m and 85-320cm, respectively. The individuals are spatially arranged in aggregation among patchy populations. The populations are well represented by reproductive individuals with 77% and pre reproductive with 23%. Seedlings of 35.9% attained a height below 1m and 64.01% of a height above 1m. Considering the extent of distribution in the state, increase in the number of mature individuals (in addition to the enumerated area), and fair count of seedlings suggests a healthier conservation status of the species in the region. The economic and medicinal values, occurrence of isolated and fragmented populations, irregularities in the flowering and fruiting period among populations, however, extends urgent concerns over the pollination biology, detection of diverse genotypes subsequent multiplication and restoration of dwindling populations for the effective conservation and management of the species in situ.

Classifying Threatened Species of India Using IUCN Criteria

Assigning threat status to a species is essential for prioritization of species under any conservation programme, and therefore, a pre-requisite for species conservation. In India, due to inadequate data, threat status has not been assigned to several plant species, although their population sizes are quite small and they are considered important from conservation point of view. Besides, there is a need for reassessment of threat status assigned by various agencies using updated data on population size, number of mature individuals, area of occupancy, and geographic extent of occurrence. This is crucial as the natural habitats as well as populations of such species are being affected by anthropogenic activities, exotic species invasion, and climate change. In the present study, we assessed the threat status of 59 selected plant species following the IUCN criteria (ver. 3.1). The species were selected after consultation with various experts throughout the country. Field surveys were carried out in various ecoregions of India to locate the species. Population size and number of mature individuals were enumerated following quadrat/plot-based sampling. The exogenous and endogenous factors leading to decline in population and rarity were identified based on field observations as well as laboratorybased seed viability and germination tests. Based on these studies, 20 species were classified under critically endangered category, 21 under endangered, 11 under vulnerable, five under near threatened, and one species each under data deficient and least concern category. Threat assessment for 41 species was done based on number of locations and geographical range of occurrence, while for 18 species it was done based on restricted population and number of mature individuals. Over-exploitation and habitat degradation or loss were the dominant exogenous factors leading to decline in natural populations of the selected species. The major endogenous factors that lead to population decline and species rarity were low seed viability and germination, long dormancy period, less seedling recruitment, low population size, habitat specificity and narrow niche leading to restricted distribution.

Population Assessment of An Endemic Tree, Croton Scabiosus Bedd. (Euphorbiaceae)

The population of Croton scabiosus, an endemic tree species of southern Eastern Ghats of Andhra Pradesh, India was assessed through random sampling in 15 localities spread over 8 locations. In sampled 37.5 h area, a total of 8737 mature individuals of Croton scabiosus was recorded. Of the 8 locations, Sanipaya sub population was found stable and considered elite owing to the maximum number of mature individuals, girth and height. In spite of good adult population, low number of seedlings and saplings of the species across the native terrain indicates its poor germination and recruitment warranting both in situ and ex situ conservation measures.

<b>A note on the population status and threats on two endemic and Endangered species of <I>Garcinia</I> of Agasthyamalai Biosphere Reserve, Tamil Nadu, India</b>

The genus Garcinia comprises c. 35 species in India many of which are endemic and economically important with immense medicinal properties. The two species viz., Garcinia imberti and G. travancorica are lesser-known endemic medium-sized straight-stemmed trees with horizontal branches. The trees are distributed in the restricted forest areas (700–1,500 m) of Agasthyamalai Biosphere Reserve. Both the species are dioecious trees and have male and female flowers in two different individuals, sometimes at a distance of a few kilometers from each other. A large number of mature individuals of these species have been over-exploited from Agasthyamalai Biosphere Reserve and therefore a few mature individuals and seedlings alone exist. The populations were severely fragmented and exist in a few locations of natural forest areas. The number of mature individuals recorded in G. imbertI and G. travancorica was 127±14 and 112±14 respectively in the entire distributional areas. There was an extreme fluctuation observed every year in the case of flowering and fruiting and also in the number of individuals due to the disturbance in the forest ecosystem. Both species have been included under IUCN threatened category and therefore they need effective conservation measures.

Ruling out genetic erosion in Picea chihuahuana Martínez

Genetic erosion has been variously defined as the loss of particular alleles, the reduction in richness of the total number of alleles, and the reduction in evenness of the frequencies of alleles in a given place within populations or across species. Picea chihuahuana Martinez is an endangered endemic species known to occur in at least 40 locations along the Sierra Madre Occidental, in the states of Durango and Chihuahua (Mexico), but covering a total area of no more than 300 ha. The total number of individuals has been estimated to be around 42,600, and the number of mature individuals may be <2500. The populations (including mature trees, saplings and seedlings) vary in size from 21 to 5546 individuals. It has been suggested that small populations may be more susceptible to loss of genetic variability via genetic erosion caused by genetic drift, endogamy depression and strong unidirectional selection. The predicted reduction and eventual disappearance of a suitable habitat for P. chihuahuana due to climatic change imposes an additional risk of extinction. The principal aim of this study was therefore to estimate genetic erosion in 14 populations of P. chihuahuana Martinez by comparing genetic diversity across diameter at breast height classes (as a proxy for age classes) by using AFLP markers and four indices of genetic diversity that are commonly applied in combination with dominant genetic markers. No evidence of genetic erosion was found in the 14 P. chihuahuana populations analyzed.

Response of rare and endangered species Picea omorika to climate change - The need for speed

Serbian spruce (Picea omorika (Pančić) Purk.) is a rare and endangered tertiary relict and endemic species, with restricted and fragmented natural range in Serbia and Bosnia and Herzegovina, mainly around the mid-course of the Drina river. Since the middle of the 19th century, its natural range declines constantly, followed by a decline in the number of mature individuals. The decline of this forest species is slow and mainly attributed to poor regeneration and low competing ability. Given the foreseen worsening of the climate in forthcoming decades, this decline can only accelerate. In recent years, dieback related to drought has been observed as response to extreme weather events suggesting that Serbian spruce will face difficulties in adapting to climate change within its natural range. However, successful use of Serbian spruce in Central and Northern Europe indicates potentially large adaptive potential of this species which, along with the high genetic variability, outweigh the limited morphological variation, self-fertilization, and limitations related to the restricted natural range in the first place, and, indicates possible directions of migration in the second place. In this paper, current conservation actions are discussed, and strategies for the species survival in a changing environment are suggested. Since migration and adaptation are the least likely responses of this species to climate change, measures such as assisted migration may be the only strategy which will enable persistence of Serbian spruce. Current conservation programs, limited to in-situ actions, need to be supplemented with ex-situ actions and strategies. In the worst case scenario, i.e. for species such as Serbian spruce which are unable to migrate and/or adapt to changing climate, the most suitable sites should be identified and colonized in order to prevent extinction in the near future.