Olenekian (Early Triassic) bivalves from the Salt Range and Surghar Range,Pakistan

Abstract: Based on newly collected material from the uppermost Smithian and lower to middle Spathian (Olenekian, Lower Triassic) of the Salt Range and Surghar Range (Pakistan), 15 bivalve species belonging to 11 genera are described, including two new genera, Eobuchia and Dimorphoconcha, and one new species, Palaeoneilo? fortistriata. Eobuchia gen. nov. is placed in a new subfamily, the Eobuchiinae, which differs from the Buchiinae in having an almost planar and only moderately inclined or offset right anterior auricle. Inclination of the right anterior auricle is proposed as a synapomorphy of the revised suborder Monotidina, which includes the Buchiidae, Monotidae, Oxytomidae and, tentatively, the Dolponellidae. The Pseudomonotidae, Chaenocardiidae and Claraiidae are discussed as candidate ancestors of the Monotidina. Dimorphoconcha gen. nov., provisionally placed in the Limidae, is a morphologically unusual genus characterized by a globose shell centre and a strongly plicate fringe. Permophorus costatus, which was previously known exclusively from Permian strata, is reported from the Spathian of the Surghar Range. This record extends the range of P. costatus for at least 8 Myr and makes it the first reported Lazarus species, with an outage of more than 2 Myr after the end‐Permian mass extinction. Ten of 15 species recognized in this study have not been reported from other regions, which may indicate increasing provincialism towards the end of the Early Triassic, or, alternatively, reflect the still insufficient knowledge of benthic faunas from the epoch that followed the greatest crisis in the history of life.     

A field study of the effect of prebaiting on censusing by the capture-recapture method in a vole population

Populations of the vole, Clethrionomys rufocanus, in a lowland woodlot of Hokkaido were studied for the presence of effects of prebaiting on censusing by the capture-recapture method. A grid of 121 live-traps, spaced 5 m apart, was laid out on each of two plots, one of which alone was prebaited three days long. Owing to very high densities and great trap-efficiency, sufficient and favourable samples could be available for statistical analysis, except the trend of delayed catch for young in sampling. The population on either plot, however, proved to be markedly variable in catchability of unmarked animals in the course of trapping; while the probability of recapture was counted as invariable on the average from day to day, the recapture frequency was different between juveniles, subadults and adults. Needless to say, the catchability was distinctly greater for marked voles than for unmarked ones, whether prebaited or not, through the trapping period, except that the first-day catchability for unmarked ones on the prebaited plot seems not to be significantly lower than that for marked ones. Consequently, it turns out that the prebaiting has almost never helped to eliminate the important bias induced by differential trap-response of marked and unmarked animals; its contribution is only that the catchability for unmarked ones is slightly higher on the part of the prebaited plot on earlier days of the period. In accordance with the heterogeneous catchability, the Γ-form distribution analogous to the geometric could be applied with thorough fitness to the capture frequency in order to estimate the whole populations. The fact that the estimates are reliable, being not at any rate underestimates, was further confirmed by the result of a follow-up work conducted by means of the removal method with wider trap-spacing which brought forth distinct underestimation chiefly referable to unexposure to traps of the partial populations. The subject of unexposure was discussed by laying stress on the relation between minimum range length and trap-spacing.     

An approach to the edge effect in proof of the validity ofDice's assessment lines in small-mammal censusing

A second fieldwork for the sake of solving the edge-effect subject was carried out in almost the same ways and plans in summer of 1971 in succession to that of 1970. It was found out that the population density was reduced to two-thirds, but the data were sufficient to form the subsequent conclusions:

1. The initial population estimated by the removal census method turned out to be well compatible with the numbers of survivals and emigrants of marked voles calculated byJolly 's method.
2. The natural, entire home ranges of both sexes reached by determining observed range length and width with 24 voles, selected on rigid conditions, agreed with those of the range-conservative type in 1970 in both acreage and elliptic shape.
3. In the majority of the select specimens, considered to reveal the natural ranges, the random distribution in number of captures per station within range was proved by means of I_σ so far as such capture density as treated here is concerned. On the ground of the empirical evidence, the above range size approached by the routine observational method could be made surprisingly accordant with the range size in terms of r-values calculated byWierzbowska 's method.
4. From these proofs, the validity ofDice 's assessment lines makes evident, and besides, it could be further substantiated by use ofMarten 's notion of mouse-equivalents through the mediation ofWierzbowska 's method.
5. Consequently, I have largely come to the conclusion thatDice 's assessment lines stand on justifiable basis from theoretical and empirical angles.

     

Diurnal temperature range and mortality in Urmia,the Northwest of Iran

Diurnal Temperature Range (DTR) is a meteorological index which represents temperature variation within a day. This study assesses the impact of high and low values of DTR on mortality. Distributed Lag Non-linear Models combined with a quasi-Poisson regression model was used to assess the impact of DTR on cause, age and gender specific mortality, controlled for potential confounders such as long-term trend of daily mortality, day of week effect, holidays, mean temperature, humidity, wind speed and air pollutants. As the effect of DTR may vary between the hot season (from May to October) and cold season (from November to April of the next year), we conducted analyses separately for these two seasons. In high DTR values (all percentiles), the Cumulative Relative Risk (CRR) of Non-Accidental Death, Respiratory Death and Cardiovascular Death increased in the full year and hot season, and especially in lag (0−6) of the hot season. In the cold season and high DTR values (all percentiles), the CRR of Non-Accidental Death and Cardiovascular Death decreased, but the CRR of Respiratory Death increased. Although there was no clear significant effect in low DTR values. High values of DTR increase the risk of mortality, especially in the heat season, in Urmia, Iran.     

A Floristic Study on the Seed Plants of the Cangshan Mountain Range,Dali, Yunnan,China

The floristic characteristic, position in Chinese floristic division, and the origin and development of the flora of the Cangshan Mountain Range (the Dali Range) were discussed from different aspects, based on the local seed plants of 2503 species, 45 subspecies, 194 varieties, belong to 852 genera in 164 families. Preliminary conclusions are as follows: The Cangshan Mountain Range belongs to three river gorges subregion, Hengduan mountain region, Sino Himalayan forest subkingdom, East Asiatic Kingdom, in Chinese floristic division. The floristic characteristic of seed plants of the Cangshan Mountain Range is temperate. Because of the geological events of the collision between Eurasian Plate and Indic Plate, the Tethys fading away, and the uplift of Himalayas, the elements from Gondwana land, Mediterranean and Arctic Tertiary gradually developed into its modern flora. The endemism within the flora is rich, with the neoendemic elements dominant. It shows that the Cangshan Mountain Range is not only a refuge for some ancient floristic elements but also a differentiation center for young floristic elements. It is an important floristic spot connecting floristic elements from different directions. And the distribution limits of a great deal of elements also are here.     

The amphibians and reptiles of Luzon Island,Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces,northern Sierra Madre Mountain Range

We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.     

Investigation into the edge effect by use of capture-recapture data in a vole population

A substantial explication of the edge effect has been attempted by use of capture-recapture data for a vole population (Microtus montebelli), gathered intwo plots of 100×100 m or less during 12 days, cheked twice daily, in August 1970; the sample was quite sufficient for the aim. The edge effect as guessed by increased catch per trap is usually suspected to ensue from range-settlers in the outside boundary strip of a plot and immigrants. But by a theoretical analysis I could attain a tentative conclusion that no increased catch per trap will occur unless any invasion takes place. Then it follows that, apart from the effect of invasion, the role of the adjoining outside settlers in the edge effect is essentially required to be studied in the light of knowledge on the truth of size and shift in home range. The variation in range behavior for 183 adult voles, captured 6 times or more, could be grouped into eight types, of which the range-conservative type possessed 52% of the sample and the group of the type was justly utilized for giving averages of range size. Besides, it was seen from the observed frequency of types that a considerable number of immigrants onto the census plot were induced perhaps being allured by trap baits, but the majority of them proved to be assigned to the voles that have their ranges inside the assessment line ofDice ; the rest referable to effective immigrants was only a few (7%). I could perceive no reason such as disproves the idea ofDice 's additional boundary strip. Viewed from maps of ingress shift of ranges, the effect of ingress must have been greater in the outer trap rows than in the inner within the plot, so that it might well be called edge effect in general; such effect, however, is seen gradually diminishing toward the center, and hence it is almost unlikely that one should find any clear-cut intra-plot assessment lines demarcating such an inner square as quite free from edge effects. Averages of observed range length and width (ORL and ORW), as reliable measures for the true range size, were determined from the above group of specimens; as a result, the remarkable concept of elliptic range shape was established by regarding ORL as long axis and ORW as short one, and, directly from these averages, the mean range sizes worked out at 0.04 for females and 0.09 for males in acreage which proved to be surprisingly well agreeable with those of isotope-revealed ranges for voles given byGodfrey (1954) andAmbrose (1969). The catchability for marked voles () was estimated by the maximum likelihood method by use ofJolly 's formulae (1965), but that for unmarked ones () was made by the regression census formula; as a result it was shown that the population was clearly of π>p type and that the trap-experience that voles underwent one month or more ago can make them retain as high catchability as π.     

Molecular phylogeny of the Australian venomous snake genus Hoplocephalus (Serpentes, Elapidae) and conservation genetics of the threatened H. stephensii

The Australian elapid snakeHoplocephalus stephensii (Stephens' BandedSnake) is patchily distributed in disjunctforest remnants in eastern Australia and islisted as threatened in both states in which itoccurs (Qld and NSW). Here we focus on thephylogeography of H. stephensii toaddress (1) the genetic distinctiveness of thistaxon within its genus and (2) the level ofgenetic diversity present within and betweendisjunct populations from throughout thespecies' range. We sequenced an approximately900 base pair DNA fragment of the mitochondrialgenome that includes half of the ND4 gene andthree tRNA genes. We obtained sequence datafrom 15 H. stephensii individuals drawnfrom four populations, plus representatives ofthe other Hoplocephalus species.Phylogenetic analyses of the data produced asingle fully resolved tree. The two coastaltaxa (H. bungaroides and H. stephensii)are very closely related (2.6–3.1% sequencedivergence) whereas the inland taxon H.bitorquatus is more distantly related to theother two (7.6% vs H. bungaroides;7.8–8.3% vs H. stephensii). Geneticdiversity is low within H. stephensii(nine mitochondrial haplotypes with 1–3haplotypes with only single base pairdifferences within populations). The largestsplit (1.7% sequence divergence) occursbetween the northern population and the threesouthern populations and corresponds to thespecies distribution north and south of theMcPherson Range on the Queensland-New SouthWales border. The three southern populationsdisplay much less molecular divergence (maximumof 0.6% sequence divergence), consistent withthe presence of generally continuous forestthroughout the species' range until Europeaninvasion of Australia 200 years ago, and withradiotelemetric studies that have found highvagility in these arboreal snakes. Thus, onthe basis of genetic distinctiveness we arguethat (1) Hoplocephalus bitorquatus shouldreceive high conservation priority; and (2)managers should treat the Queensland and NSWpopulations of H. stephensi as separateconservation units.     

Of mice and wrens: the relation between abundance and geographic range size in British mammals and birds

We examine the relation between population size and geographic range size for British breeding birds and mammals. As for most other assemblages studied, a strong positive interspecific correlation is found in both taxa. The relation is also recovered once the phylogenetic relatedness of species has been controlled for using an evolutionary comparative method. The slope of the relation is steeper for birds than for mammals, but this is due in large part to two species of mammals that have much higher population sizes than expected from their small geographic ranges. These outlying mammal species are the only ones in Britain to be found only on small offshore islands, and so may be exhibiting density compensation effects. With them excluded, the slope of the abundance–range size relation for mammals is not significantly different to that for birds. However, the elevation of the relation is higher for mammals than for birds, indicating that mammals are approximately 30 times more abundant than birds of equivalent geographic range size. An earlier study of these assemblages showed that, for a given body mass, bats had abundances more similar to birds than to non-volant mammals, suggesting that the difference in abundance between mammals and birds might be due to constraints of flight. Our analyses show that the abundance–range size relation for bats is not different for that from other mammals, and that the anomalously low abundance of bats for their body mass may result because they have smaller than expected geographic extents for their size. Other reasons why birds and mammals might have different elevations for the relation between population size and geographic range size are discussed, together with possible reasons for why the slopes of these relations might be similar.     

Target detection and range resolution by the big brown bat (Eptesicus fuscus) using normal and time-reversed model echoes

Summary Big brown bats (Eptesicus fuscus) were tested for their ability to detect an electronically simulated target, and to discriminate differences in range to two simulated targets, when receiving either a model of their own sonar emissions or the model reversed in time as the echo. The theory of matched detection predicts a large decrease in performance if bats use matched filtering, unless they are somehow able to adjust their filter to match the novel, time-reversed signal. The detection thresholds we obtained were much lower than Møhl's (1986), but like him we found no difference in threshold for reversed models (Table 2). This suggests either that bats do not use matched filtering for target detection, or, possibly, that they are able to adapt their filter to a highly unnatural signal in some way as yet unknown.Unlike detection, range discrimination was much poorer with reversed echoes (Table 3). Threshold increased from about 1 cm range difference with normal model echoes to 18 cm or more with reversed model echoes. This suggests that range determination, which is based on measuring the time of arrival of echoes, does involve matched filtering. Whether such filtering is ideal (i.e., equivalent to cross-correlation detection) cannot be decided by our results, but there are some indications that the match between an echo and the presumed internal template (the match of matched filtering) must be fairly precise. Also, since performance with phantom targets generated using model echoes was as good as has been found with real targets, the internal template is probably fixed (or only slowly modifiable) rather than re-programmed with each sonar emission. Finally, because synchronization of emission and model echo was not perfect, the apparent distance to targets probably varied by 2 to 4 cm from emission to emission, although both targets would appear to move together thus keeping the range difference constant. This suggests that bats determined range to the targets simultaneously rather than sequentially, as is usually assumed.Abbreviations BP bat-produced echo - FM frequency modulated - M _d detection model echo - M _d reversed detection model echo - M _rd range discrimination model echo - M _rd reversed range discrimination model echo - rms root mean square - SCR signal-to-clutter ratio - SNR signal-to-noise ratio - SPL sound pressure level - XCF crosscorrelation function     

The recent expansion of the brown hare (<Emphasis Type="Italic">Lepus europaeus</Emphasis>) in Sweden with possible implications to the mountain hare (<Emphasis Type="Italic">L. timidus</Emphasis>)

The brown hare (Lepus europaeus) expanded its Swedish distribution since the 1980s northwards and locally to new areas within its former range. Of 115 brown hare populations within the former range reported in a hunter enquiry, those established after 1980 were situated higher above the sea level than older ones and higher than neighbouring (<50 km) older populations. Reports on increased use of forest habitats by brown hares were equally frequent among recent and older populations, suggesting a process promoted solely by less harsh winters. Supposed hare hybrids were more often reported from hunting grounds with recent brown hare establishment, i.e. where the species expands in time and in space. In a 27-year dataset on brown hare observations, the recent increased use of forest habitats was supported in that maximum distances to agricultural land for brown hare sightings were higher in mild winters, whereas the proportions of the annual observations made during winter were lower. In 40-year bag records from two Swedish counties, the dynamics of the mountain hare (Lepus timidus) responded positively to snow parameters, whereas brown hares responded negatively. We suggest that the state of mountain hare populations primarily depends on winter conditions and predation pressure, whereas possible effects of hybridization are unclear. If winter conditions remain as in the last 15 years, mountain hare numbers are not likely to increase in southern Sweden, whereas the brown hare may expand even further. In either case, hybrids will occur in sympatric areas in frequencies probably related to the density of the respective true species.     

Middle and Upper Jurassic bivalve associations from the Iberian Range (Spain)

The four sections richest in bivalves from the Middle and Upper Jurassic of the Iberian Range (Spain) were selected for a quantitative palaeoecological analysis of the bivalve fraction of the macrobenthos. Five bivalve associations and two assemblages were recognized with the help of a Q-mode hierarchical cluster analysis (Ward method). The main environmental factors controlling bivalve associations are thought to be substrate, water energy and distribution of organic matter. The bivalves exhibit a distinct spatial and temporal distribution pattern within the Aragonian Branch of the Iberian Range. Four of the bivalve associations occur in the Upper Oxfordian (Sot de Chera Fm) and one association in the Lower Callovian (Chelva Fm). In the Sot de Chera and Loriguilla formations, the abundance of bivalves decreases from NW to SE i.e., from relatively close to the shore line towards the distal-most part of the carbonate platform. In the Chelva Fm, bivalves are abundant in the Ariño region, interpreted as a palaeogeographic high. The spatial distribution of bivalves might have been largely controlled by the availability of nutrients.     

Recent and historical range shifts of two canopy-forming seaweeds in North Spain and the link with trends in sea surface temperature

Geographical range shifts of two canopy-forming seaweeds, Himanthalia elongata (L.) S.F. Gray and Fucus serratus L. were investigated at their southern range boundary in Northern Spain from the end of nineteenth century to 2009. Given the good dispersal abilities of H. elongata and its short life-span, we hypothesize that this species will track environmental changes at a faster rate than the perennial and short-distance disperser F. serratus. Our results show a continuous and drastic westward retraction of H. elongata, which has nowadays virtually vanished in Northern Spain, whereas F. serratus is still found in the westernmost area. Despite this, the first species is still relatively abundant in the Iberian Peninsula, whereas the presence of the latter is scattered and reduced. Overall, range shifts fit with the warming trend in sea surface temperature (SST), whereas it is unlikely that increases in grazing pressure or coastal pollution have driven the observed changes, particularly the rapid trend in recent years. Differences in species traits are linked to range dynamics. The higher persistence of F. serratus at eastern shores may thus be related to its longer life span and its greater thermal tolerance. The presence of sporadic populations of H. elongata outside the zone of continuous distribution can be attributed to long-distance dispersal events during cold pulses. Relict populations in isolated and estuarine locations were left behind in the contracting range margins, particularly for F. serratus. In Northern Spain, the westward retreat of large canopy-forming algae seems to be a general phenomenon, involving other species such as kelps. Therefore, an evident reorganization of coastal assemblages is expected, though the temporal extent of changes and the consequences for ecosystem services need to be evaluated.     

青藏高原特有植物露蕊乌头 (毛茛科) 从冰期避难所扩张后繁殖资源分配的变化

物种分布范围的形成是进化生态学研究的基本问题之一,但植物的资源分配策略是否与物种边界形成有关一直没有相关研究。青藏高原特有植物露蕊乌头在末次最大冰期时有4个避难所,但冰期后只有一个避难所的种群发生了扩张并最终形成了现代分布格局。以露蕊乌头的避难所种群（同仁种群）和扩张后邻近分布区边缘的两个种群（兴海种群和海北种群）为研究对象,通过比较避难所种群和边缘种群的资源分配方式,探讨露蕊乌头的资源分配与该植物分布区及边界形成的关系。结果发现：1）兴海和海北种群的营养结构（包括根、植株高度和茎叶生物量）均显著低于同仁种群,海北种群的繁殖结构（花数量和花生物量）显著低于同仁和兴海种群,但海北和兴海的繁殖分配均显著高于同仁种群;2）3个种群的繁殖资源与个体大小呈现显著的正相关关系,投入到繁殖资源的比例（繁殖分配）与个体大小呈显著的负相关关系。对露蕊乌头的研究结果一方面进一步证明了个体大小依赖的繁殖分配,但不符合“植物开始繁殖必须达到一定的大小（阈值）”这一结论,这可能与露蕊乌头的生活史特征有关;而另一方面,露蕊乌头在扩张过程中逐渐增加了对繁殖资源投资的比例,说明胁迫生境中有性繁殖对该植物具有更为重要的意义,且露蕊乌头在扩张过程中可能逐渐实现繁殖产出最大化,并可能在边缘种群实现最优繁殖分配进而最终形成该物种分布区的边界,但这一结论仍需在更多的植物类群中验证。     

Aspects of interspecific interaction betweenReithrodontomys megalotis andMicrotus montanus in one acre enclosures

1. Two one acre enclosures were cleared of all resident rodents, and then, one enclosure was seeded with founder populations of Reithrodontomys megalotis (grid M) and the other with Reithrodontomys megalotis plus Microtus montanus (grid I). Founder populations consisted of eight animals for each species introduced and a sex ratio of 1∶1.
2. Five parameters were measured for a period of one year. Data collection was started in September 1971, and ended in September 1972; enumeration was conducted twice a month for three days.
3. The five parameters measured were: (1) population density through time and individual growth rates; (2) reproduction; (3) survival of age and sex classes; (4) sex ratio; and (5) sizes of home ranges.
4. There were no significant differences in three out of the five parameters studied. Density estimates along with individual growth rates were not significantly different between the grids. Reproduction, including breeding season and efficiency of reproductive effort, showed no or very little variation due to interspecific interaction. Home range sizes did not appear to be significantly different between the grids. Survival of juvenile males on grid I seemed lower and juvenile males from grid I were significantly smaller although possibly younger than those of grid M. The sex ratio of grid I was significantly different from the expected 1∶1 ratio.
5. It is postulated that Reithrodontomys megalotis may regulate their density by alteration of their sex ratios.

     

Small and overlooked: Phylogeny of the genus Trigonodactylus (Squamata: Gekkonidae), with the first record of Trigonodactylus arabicus from Jordan

Geckos of the genus Trigonodactylus are widely distributed in the sand deserts of the Arabian Peninsula. Three species of this genus are currently recognized, with a fourth one, Stenodactylus pulcher, which placement within Trigonodactylus has been tentatively suggested, but not yet confirmed. We present a phylogenetic analysis of the genus Trigonodactylus with new specimens collected in central Saudi Arabia and southern Jordan. New genetic data has been generated from three mitochondrial markers to investigate the phylogenetic relationships of all species of the genus and to assess the putative generic assignment of S. pulcher. Our results confirm that S. pulcher indeed belongs within Trigonodactylus, branching as a sister lineage to all other species of the genus. The new samples cluster within Trigonodactylus arabicus, thus confirming the genetic homogeneity of the species across its large and seemingly inhospitable range. The new specimen collected in southern Jordan represents the first record for the country and a considerable range extension to the northwest from all previously reported localities. Our findings and discovery of a new species for Jordan highlight the need of more field surveys to be carried out in the underexplored parts of Jordan and northern Saudi Arabia, as these places still hold a potential for new discoveries and are crucial for understating the biogeography of the Arabian herpetofauna.     

贺兰山东坡低山区植被种类组成区域分异与植被性质的分析

本文以定量和定性分析相结合,分析了贺兰山东坡海拔1200—1900m低山区范围内植被种类组成的区域分异、植被性质及生态条件的区域分异特点。结果表明,该范围内务主要植被类型具有荒漠草原或荒漠草原化的共同特点,其种类组成均在北、中、南不同地段存在一定差异。此差异反映出本区海拔1600m以上的中部地段及其以下的北部地段分别是生态环境最湿润和最干旱的区域．     

Changes in Reproductive Allocation after Expansion from the Glacial Refugium and Implications for the Distribution Range in the Qinghai Tibet Plateau Native Herb,Gymnaconitum gymnandrum (Ranunculaceae)

A fundamental goal of ecology and evolution is to explain patterns of species distribution and abundance. However, the way in which stable distribution ranges are shaped by natural selection is still poorly understood, especially whether patterns of resource allocation have contributed to the range size and the formation of range boundary received little attention. For annual herb, the maximum reproductive allocation is predicted to be 50%, and thus we predicted that reproductive allocation might contribute to the formation of range boundary since plant will enhance allocations to reproduction in stressful environments. In this study, we presented our data on resource allocation between population from the glacial refegium and those from the marginal populations in Gymnaconitum gymnandrum, an alpine biennial native to the Qinghai Tibet Plateau, aiming to find the contribution of resource allocation to the formation of range boundary. Our results showed that resource allocations to vegetative organs, including roots, plant height and stem leaf biomass, were significantly higher in the refugium population that in the two marginal populations, and allocations to reproductive organs, including flower number and flower biomass, were significantly lower in one marginal population (Haibei population) than in the other marginal population (Xinghai population) and the refugium population (Tongren population). However, reproductive allocation was significantly higher in the marginal populations than in the refugium population. In addition, in each of the three populations, we found a positive relationship between the plant size and flower biomass but a negative relationship between the plant size and reproductive allocation. Our results indicated a size dependent reproductive allocation in Ggymnandrum, but we did not find a size threshold for reproduction in each of the three populations of this plant, which might be attributed to the life history of this biennial herb. We also suggested that reproductive allocation was increased during the process of range expansion and may rise to the optimal reproductive allocation in the marginal populations, which suggested the important role of sexual reproduction for plants in more stressful environments and the formation of range boundary. However, these conclusions need to be further proved in other plant species.     

An Analysis of the Flora of Qinling Mountain Range: Its Nature,Characteristics, and Origins

The Qinling Mountain Range, which covers an area of ca. 76500km² and ranges from 32°05′ to 34°45′ N and from 104°30′ to 115°52′ E, is a major watershed of the Huanghe and Chang jiang rivers with the highest peak about 3767 m above sea level. The flora comprises ca. 3124 species in 892 genera, of which 51.9% of species and 4.4% of the genera are endemic to China. Evoluated in this paper is the importance of the 20 larger fami lies which together contain 65.2% of the total number of species. The phytogeographical affinities of genera of seed plants in the flora are analyzed and briefly discussed. Among the native genera of the flora of the Qinling Mountain Range, 220 (26.8%) are tropical, 563 (68.5%) temperate, and 39 (4.7%) endemic to China. It is clear from the figures that temperate genera play an important role in the flora and vegetation of the Qinling Mountain Range. The features of the flora include the unusually high proportion of endemic species, a wealth of Sino-Japanese elements and prominant temperate nature in compsition. On the ba sis of analysis of paleobotanical materials in the Qinling Mountain Range and adjacent areas, historical distribution of dominant species, and the origin and relationships of Chinese en demic genera occurring there, the flora is of outstanding originality. No doubt, the rich and diverse flora have evolved gradually and autochthonously at least since the latest Cretaceous.