Central Mountain Range Research Articles

Genetic variation and population differentiation of Michelia formosana (Magnoliaceae) based on cpDNA variation and RAPD fingerprints: relevance to post-Pleistocene recolonization.

We used sequence variation of the atpB- rbcL intergenic spacer of cpDNA and nested clade analysis to assess the phylogeographic pattern of Michelia formosana, a species restricted to Taiwan and the Ryukyus. In total, 31 haplotypes were identified and clustered into four major chlorotypes. Genetic composition of nearly all populations was heterogeneous and paraphyletic phylogenetically. Although the apportionment of cpDNA variation hardly revealed a geographic pattern due to the coancestry of dominant sequences, some chlorotypes were restrictedly distributed. According to the patterns of clade dispersion and displacement, a reconstructed minimum spanning network revealed that historical events of past fragmentation and range expansion, associated with glaciation, may have shaped the phylogeographic patterns of M. formosana. Four possible refugia were identified: the Iriomote and Ishigaki Islands (the southern Ryukyus), Wulai (northern Taiwan), and Nanjen (southern Taiwan), on the basis of the interior positions of their haplotypes in the network and the high level of nucleotide diversity. Given insufficient time for coalescence at the cpDNA locus since the late Pleistocene recolonization, lineage sorting led to low levels of genetic differentiation among populations. In contrast, hierarchical examination of the random amplified polymorphic DNA (RAPD) data scored from six populations across three geographical regions, using an analysis of molecular variance (AMOVA), indicated high genetic differentiation both among populations (Phi(ST) = 0.471) and among regions (Phi(CT) = 0.368). An unweighted pair group method with arithmetic mean (UPGMA) tree of the RAPD fingerprints revealed that populations of two offshore islands of eastern Taiwan ( M. formosana var. kotoensis) were clustered with geographically remote populations of the Ryukyus instead of those in southern Taiwan, suggesting some historical division due to geographic barriers of the central mountain range. In contrast to the paraphyly of the nearly neutral cpDNA alleles, differentiated RAPDs may have experienced diversifying selection.

Conductivity distribution and seismicity in the northeastern Japan Arc

Wideband magnetotelluric (MT) observation data were obtained from 91 sites along six transects in the central part of the Japan Arc. Here, a quasi-3D georesistivity distribution, in addition to other geophysical and geological parameters, is used to better understand seismicity in the region. We found that high seismicity in the Central Mountain Range is due to relatively poor fluid saturation caused by volcanism. The high conductive fracture zone in the west of the Central Basin without big earthquakes is characterized by a low Poisson ratio. It is suggested that strains cannot be accumulated in those regions. The Miyagi-ken-hokubu region with a frequent occurrence of large earthquakes, is conductive—high Poisson ratio—high Vp suggesting that the zone is relatively fluid-rich and brittle.

A new athecate earthworm of the genus Amynthas Kinberg (Megascolecidae: Oligochaeta) from Taiwan with discussion on phylogeny and biogeography of the A. illotus species-group

This paper describes a new species of athecate earthworm belonging to the illotus species-group of the genus Amynthas Kinberg from Taiwan. It is Amynthas hohuanmontis sp. nov. from Mt Hohuan at an elevation of 3000 m in the Central Mountain Range. The athecate earthworm Amynthas pusillus (Ohfuchi) from Ishigaki Island, Riukiu is found to be synonymous with Amynthas assacceus (Chen) from Hainan Island, China. Accordingly, the A. illotus species-group currently consists of A. hohuanmontis sp. nov. from Taiwan, A. illotus (Gates) from Yunnan and Riukiu, A. assacceus (Chen) of Hainan and Riukiu, A. sheni (Chen) from Hong Kong and A. oyuensis (Ohfuchi) from Japan. Based on characters of particularly the porophore structure, the five species are divided into two species-subgroups: the sheni species-subgroup of A. sheni and A. hohuanmontis, and the assacceus species-subgroup of A. illotus, A. assacceus and A. oyuensis. The two subgroups might have differentiated from two independent ancestors. The five species show an arc-shaped distribution in the peripheral regions of the East Asian continent (Yunnan, Hainan, Hong Kong, Taiwan, Riukiu and Japan), suggesting them to be survivors from the Pleistocene ice ages.

Numerical Simulations with MM5 3DVAR Initialization

The recently developed MM5 three-dimensional variational (3DVAR) assimilation system at NCAR has been used to investigate influences of ingested sounding and ship observation data on numerical simulations of severe weather in the vicinity of Taiwan. Three weather events were simulated in this study, which include a Mei-Yu front in June 1998, Supertyphoon Bilis in August 2000 and Typhoon Nari in September 2001. For the Mei-Yu front, the simulated low-pressure system northeast of Taiwan is stronger. when the 3DVAR is performed during initialization. The simulated patterns of heavy rainfall just off the southern tip of Taiwan are also closer to observations for the run with 3DV AR. For the second case of Typhoon Bilis, both runs with and without 3DVAR show a northward bias in track upstream of eastern Taiwan. However, due to less northward track deflection, the simulated heavy rainfall in Taiwan for the 3DV AR run is in better agreement with observations. For the no-3DVAR run, the simulated Typhoon Nari consistently moves southwestward toward Taiwan but then makes an incorrect landfall at northwestern Taiwan. With 3DVAR, the track simulation is improved with a landfall position at northeastern Taiwan. During landfall, the associated could convection is enhanced as the intense vortex core is in confrontation with the leading edge of the Central Mountain Range (CMR) and its movement is slowed down along the northwestern coast. The combination of both compression and stagnation of the embedded convective system may explain the extremely intense rainfall in northern Taiwan. The feature of observed intense rainfall over the southwestern slope base of the C／MR is also captured, but the intensity is considerably underpredicted due to lagging and weakening of the vortex core at later -times for both runs with and without 30V AR. The track simulation at later times has also been improved in the 3DVAR run, but the associated geometric distributions of 72h accumulated rainfall amounts in general are similar to those without 3DVAR. In the typhoon experiment with a bogus vortex, the 3DVAR rum preserves the initial vortex, quite well. However, the rainfall and track simulations are not improved by the ingestion of the bogus vortex for both runs with and without 3DVAR.

Orographic Influences on Rainfall and Track Deflection Associated with the Passage of a Tropical Cyclone

Abstract In this study, a nonhydrostatic mesoscale model [Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS)] was adopted to simulate Supertyphoon Bilis (2000) and investigate the dynamics of orographic rain and track deflection accompanying the storm as it passes the Central Mountain Range (CMR) of Taiwan. Both the storm track and its associated orographic rainfall distribution are well predicted by the numerical model. The intensity of the storm is underpredicted, resulting in a discontinuous track, due to the lack of specifying a “bogus” vortex at the time of model initialization. Cyclonic curvature of the storm track over the island topography track as well as major circulation features are similar to previous studies of landfalling typhoons affecting Taiwan. The model overpredicts the total amount of accumulated rainfall. Generalization of the flux model proposed in a 2001 study by Lin and coauthors is used to help predict and understand the observed rainfall distribution by calculating bo...

Typhoon Rainfall over Taiwan Area: The Empirical Orthogonal Function Modes and Their Applications on the Rainfall Forecasting

Distribution of 6-h accumulated typhoon rainfall over Taiwan area is investigated through empirical orthogonal function (EOF) analysis. The data set used includes the rainfall of 20 Central Weather Bureau surface stations when typhoons were inside the domain between 18°N and 28°N, 116°E and 126°E, from 1961 to 1996. Analysis results show that the first three EOF modes are well separated from the other modes. Those three modes contain about 66% of the total rainfall variances. At some stations, only those three modes can effectively represent the station rainfall. The first EOF mode not only reveals the in-phase increasing or decreasing rainfall at all stations of Taiwan but also shows that larger rainfall occurs at stations with higher elevation and larger slope. The enhancement of rainfall in mountainous areas is an indication of topography effect on redistributing rainfall. The second mode and the third mode both show out-of-phase distribution of rainfall over Taiwan when typhoons are nearby. The rainfalls are enhanced on the up-wind sides of the mountain, and the rainfalls are suppressed on the down-wind sides. Those distributions again reveal the effects of redistributing rainfall by Central Mountain Range of Taiwan. To demonstrate how the EOF modes may be used on typhoon rainfall forecasting, several forecasting methods are evaluated. Those methods include four basic methods and four ensemble forecasts. The basic methods are: Climatology Average Method, Deviation Persistence Method, regression equation forecast based on station rainfall, and regression equation forecast based on the amplitude of the first three EOF modes. The ensemble forecasts are the simple averages taken from the last three basic methods. The results show those basic methods are compatible with each other, except the Climatology Average Method that underestimates all heavier rains and is outperformed by the others. Since the amplitudes of EOF modes depend on how the rainfall is distributed spatially over all stations of Taiwan, a forecast method based on EOF modes is capable of providing different information from other methods that based on factors only related to a single station. The study also shows that the ensemble forecasts outperform their corresponding member forecasts.

Population Dynamics of Eleutherodactylus coqui in Cordillera Forest Reserves of Puerto Rico

Various aspects of population structure and dynamics of Eleutherodactylus coqui in two forest reserves (Maricao and Guilarte) of the central mountain range of Puerto Rico were determined between July 1997 and June 1998. Adult density ranged from 8–25 animals/100 m2 for the wet season and 3–19 animals/100 m2 for the dry season. Abundance of froglets and juveniles was also greater in the wet season compared to the dry season. By contrast, egg mass counts were greater in the dry season compared to the wet season. Adult body size increased from wet to dry season as population density declined and was found to differ significantly between forests. Adult E. coqui trapped at similar elevations were larger in Guilarte compared to those in Maricao. Average body size for Maricao and Guilarte populations were smaller than those reported for populations in eastern Puerto Rico. Comparing average snout–vent length among frogs from the Luquillo Mountains, Guilarte Forest, and Maricao Forest, a gradient of decreasing body size was observed from east to west across the island.

Synoptic weather patterns and their relationship to high ozone concentrations in the Taichung Basin

Frequent high ozone days (defined as daily maximum ozone concentration ⩾80 ppb) during recent years in the Taichung Basin have caused much concern. High ozone days occur mainly during autumn and spring. Statistically, there is no clear linear relationship between a single meteorological variable and ozone concentration. In this study, data from 1996–2000 has shown that high ozone concentrations occur during two types of synoptic weather patterns. The first type is a continental cyclone emanating from mainland China, the southern part of it swept towards Taiwan by easterly winds. The second pattern is a tropical depression moving northwards toward the region, the northern part of it affecting Taiwan via easterly winds. Both types cover Taiwan with easterly winds, which are blocked by the Central Mountain Ranges (altitude of 2000–3000 m). The ranges create lee cyclogenesis to the west, which is unfavorable for pollutant dispersion and leads to serious air pollution episodes. The statistical results of the synoptic weather patterns in relation to ozone concentrations are based on the 5 yr data (1996–2000). This was obtained from a network of air-pollution monitoring sites in the study area, while the vertical data come from two 3-day tethersonde experimental campaigns conducted during March and October 2000, measuring air pressure, air temperature, relative humidity, wind speed and direction, non-methane hydrocarbons, NO x and O 3.

Evolución de la vegetación en el sector septentrional del macizo de Ayllón (Sistema Central). Análisis polínico de la turbera de Pelagallinas

Pollen and charcoal analyses of a core from Pelagallinas peatbog, located in the Sierra de Alto Rey at the eastern sector of the Central Mountain Range (Guadalajara), show the environmental history of the montane vegetation during the last 4000 years. The results indicate the importance of pinewoods in the landscape of these mountains. These pine forests were replaced by heather communities contemporaneous with fires as indicated by the increase of particles of charcoal. Birch found refuge in peatbogs, though it nearly disappeared during the last millennium. The Pelagallinas' sequence shows a remarkable and constant presence oi Fagus throughout the core, providing the oldest date for the occurence of this taxon for the Central Mountain Range.

Population differentiation and phylogeography of Hygrophila pogonocalyx based on RAPDs fingerprints

Genetic variation of the endangered species, Hygrophila pogonocalyx Hayata (Acanthaceae), was estimated based on RAPD fingerprints. According to the criteria of the International Union for Conservation of Nature and Nature Resources, H. pogonocalyx is on the Red List Category due to its endangered status. Entomophilous plants of H. pogonocalyx are mostly pollinated by honeybees. Gene flow between populations is constrained by the migratory capacity of the pollinators. A survey based on RAPD fingerprinting using 50 random primers revealed the distribution of genetic variation following an “isolation by distance” model. A hierarchical AMOVA analyses indicated significant differentiation between geographical regions ( Φ ct=0.934; P=0.048), among populations ( Φ st=0.945; P<0.001), and among populations within region ( Φ sc=0.169; P<0.001). The differentiation between geographic populations may be ascribed to a long isolation since the formation of the Central Mountain Range 1 million years ago. In contrast to low levels of genetic variation in many endangered species, some genetic processes avoiding selfing may have evolved in H. pogonocalyx. Somatic mutation also possibly contributed to the variability maintenance within populations with limited size.

Phylogenetic and evolutionary insights into the Saxifraga pentadactylis complex (Saxifragaceae): variation in nrITS sequences

Variation in nrlTS sequences among seven members of a seemingly natural group of Saxifraga (the S. pentadactylis complex; series Pentadactyles) is phylogenetically analyzed. The two most parsimonious trees indicate that the S. pentadactylis complex is not a monophyletic group, because 5. intricata is excluded and is most closely related to S. exarata (series Cespitosae). A well‐defined lineage includes, however, six of the seven members of the S. pentadactylis complex. The tree topology suggests that this remaining group of six taxa may have diverged in the northeastern part of the Iberian Peninsula. Two sublineages can be identified from the ITS phylogenetic reconstruction: S. losae‐S.moncayensis and the three subspecies of S. pentadactylis (subspp. pentadactylis, willkommiana, and almanzorii). The relationships between S. losae and S. moncayensis provide an example of north‐south speciation along the Sistema Ibérico mountain range. The three subspecies of S. pentadactylis form a monophyletic group resolved into one clade containing subspp. willkommiana and almanzorii, sister to subsp. pentadactylis. The molecular evidence agrees with chorological, cytotaxonomical, chemosystematic, and reproductive data indicating two differentiation patterns within S. pentadactylis. Transition to predominant autogamy in subsp. almanzorii probably resulted in rapid reproductive isolation from the outcrossing subsp. willkommiana in part of the Sistema Central mountain range, as suggested by their two distinct floral types but similar ITS sequences. Allopatric separation of populations of subsp. willkommiana from subsp. pentadactylis (the Pyrenees) has resulted in molecular divergence and some morphological differentiation.

Endemism in the Australian flora

AimTo detect centres of vascular plant endemism at a continental scale by analysis of specimen‐based distributional data and to relate any pattern to environmental factors and history.LocationAustralia.MethodsPresence of 8468 seed plant species‐level taxa throughout continental Australia and Tasmania was mapped on a 1° grid to visualize the pattern of species richness. This sample comprises half the known flora. Three indices of endemism were calculated but we preferred one that is unrelated to species richness, so that these two concepts could be distinguished in practice. Centres of endemism were detected by simple mapping and by spatial autocorrelation analysis (SAC). Linear regression was used to examine the relationship of the patterns of species richness and endemism to latitude, topography and climate.ResultsBoth species richness and endemism vary greatly across the continent but in most cases the same centres were high in both richness and endemism. Twelve distinct centres were identified. The major centres of both diversity and endemism are south‐west western Australia, the Border Ranges between New South Wales and Queensland, the Wet Tropics near Cairns, Tasmania and the Iron‐McIlwraith Range of eastern Cape York Peninsula. The last centre appears to be more significant than recognized by past authors. Whether this is a true Australian centre of endemism, or is largely an outlier of the flora of Papua New Guinea, is explored. Another centre, in the Adelaide–Kangaroo Island region, has been overlooked altogether by previous authors. Regression analysis did not find a simple climatic explanation of the observed patterns. There was a suggestion that topographic variation within the 1° cells may be positively correlated with endemism, which is consistent with mountainous regions functioning as refugia. One clear result is that all the major centres of endemism are near‐coastal. A likely explanation is that Pleistocene expansions of the central desert have been a powerful limitation on the viability of refugia for narrowly endemic species. All the centres of endemism lie outside the estimated limits of the expanded arid zone at the last glacial maximum (18,000 yr BP). In particular, the ‘Central Australian Mountain Ranges centre of plant diversity and endemism’ ofBoden &amp; Given (1995)is detected as a strong centre of species richness, but not at all as a centre of endemism. This is despite good sampling of this region.Main conclusionsEndemism can be distinguished from species richness by using an appropriate index and mapping of such indices can detect centres of endemism. This study demonstrates the value of specimen based distributional data, such as is held in state herbaria and museums.

Hazard assessment in Eastern Taiwan

Introduction The topography of Taiwan is dominated by the Central Mountain Range, which has steep, densely vegetated slopes, deeply incised valleys and fractured, unstable rock masses. Although most of the population is located on the low-lying coastal plains, there is a need in this rapidly developing island to construct transportation links through the mountains. Unfortunately, the steep topography makes development difficult and there have been many instances in which poor terrain evaluation has led to inappropriate engineering solutions. This paper outlines how landslide hazard assessment is being used as part of the planning process for the development of infrastructure along one such road through the mountains. The physical setting of Taiwan Taiwan is located on the eastern margin of the Eurasian continental plate (Fig. 1). The island, which is approximately 385 km in length and 143 km in width, has formed as a result of the ongoing collision of the Philippine Sea (oceanic) and Eurasian (continental) plates. Damaging, shallow seismic activity is frequent. The most seismically active region is in the central portion of the east coast of the island. However, the recent ‘Chi-Chi’ earthquake of 21 September 1999 occurred in the centre of Taiwan and caused the loss of over 2100 lives and induced damage island-wide. Terrain evaluation in Taroko National Park Taroko National Park is located on the eastern margin of Taiwan 121°40′ E and 24°0′ N (Fig. 1). It is centred upon the drainage basin of the Li-Wu River, with terrain that varies from lowland plains

CLADISTIC ANALYSIS OF THE CHILEAN GENUS CALLYNTRA SOLIER (COLEOPTERA: TENEBRIONIDAE), WITH DESCRIPTION OF A NEW SPECIES

The South American genus Callyntra (Pimeliinae: Nycteliini) comprises 16 previously known species distributed in central Chile, plus a new species described from the central coastal mountain range: C. cantillana n.sp. A cladistic analysis of the 17 species of Callyntra is conducted. Callyntra comprises a natural group of species, characterized by nine synapomorphies from external morphology and internal skeletal anatomy. The species relationships are resolved. The paper includes scanning electron micrographs of the pronotum and clypeus of the new species. A discussion concerning the status of conservation of the five areas of endemism for Callyntra using the phylogenetic information is presented.

Two new species of protandric pheretimoid earthworms belonging to the genus Metaphire (Megascolecidae: Oligochaeta) from Taiwan

This paper describes two new species, each consisting of two subspecies, of protandric, octothecal pheretimoid earthworms from Taiwan. They are Metaphire paiwanna sp. nov. typica, Metaphire paiwanna var. liliumfordiI subsp. nov., Metaphire bununa sp. nov. typica and Metaphire bununa var. glareosus subsp. nov. The var. typica of both new species occurred on the west side of the Central Mountain Range, whereas the subspecies, liliumfordi and glareosus, occurred on the east side of the range. Apparently, the Central Mountain Range constitutes a geographical barrier for isolation and subspeciation. Metaphire paiwanna has a male disc medial to male pore (opening of copulatory pouch) with a horizontal ridge, the character shared by holandric and sexthecal Amynthas swanus (Tsai) of Taiwan and Metaphire aggera (Kobayashi) of Korea and Manchuria, whereas M. bununa resembles more closely holandric, octothecal Metaphire riukiuensis (Ohfuchi) of the Riukiu Islands than protandric, octothecal Metaphire stephensoni (Michaelsen) of Indochina.

Soil alteration processes on granite in the Central Mountain Range (Spain)

Soil alteration processes on granite in the Central Mountain Range (Spain)

Une méthode pour mesurer et spatialiser une contrainte climatique : l'enneigement sur le réseau routier du Massif central

A method to measure and spatialise a climatic constraint: snow on the road network in the Massif Central mountain range in central France. — This paper presents a method for measuring objectively and spatialising the constraints stemming from the snowing over of a road network. Situations of slowed and blocked of traffic are expressed using standard meteorological indicators, measured in terms of risk. The values of the risk indicators are calculated for 518 spatial units of 25 km2 making up the study area. The maps constructed from the risk indicators make it possible to isolate the sectors with the worst traffic problems. The overall weight of the constraint is determined by crossing these data with data on the degree of remoteness of the territories.

Buena Vista: life and work on a Puerto Rican hacienda, 1833-1904

This book traces the history of Buena Vista, an estate located in the southern foothills of Puerto Rico's central mountain range. Now a popular living history museum, Buena Vista flourished in the nineteenth century--first as a farm that furnished food for the city of Ponce and surrounding plantations, later as a producer of corn and cornmeal ground at the estate's water-powered mill, and finally as a coffee plantation. Drawing on an impressive range of primary sources, Guillermo Baralt portrays the estate's history as a series of overlapping changes: from slavery to salaried labor, from primitive processing techniques to the latest in mill technology, from Spanish rule to American control, and from hard-scrabble country life to life as part of the world marketplace. Richly illustrated and written in a lively narrative style, Buena Vista paints a compelling portrait of an era, an island, a family, and an estate, bringing a period in Caribbean history to vivid life. |This translation of a Caribbean classic vividly captures the full history of Buena Vista, the 19th-century Puerto Rican estate that is now a popular living history museum.

Self-similarity dimensions of the Taiwan Island landscape

This paper adopts a three-dimensional box-counting method for computing self-similarity dimensions in a landscape study based on the digital terrain model (DTM) data of Taiwan Island. The DTM data was obtained by an aerial survey with a resolution of 40 by 40 m. The self-similarity dimension has a negative exponential relationship with its elevation. The self-similarity dimension ranges from 2.6 to 2.8 when the elevation is over 1000 m. On the other hand, in the foothills and plains region of western Taiwan, which is mainly under 1000 m elevation, the self-similarity dimension increases rapidly from 2.0 to 2.6 as the elevation increases from sea level to 1000 m. The self-similarity dimensions of different geographic regions of Taiwan Island are: western plains: 2.0; the western Foothills: 2.25–2.5; Central Mountain Range: 2.75; the Tatun volcanic area (northern Taiwan): 2.5; Coast Range of eastern Taiwan: 2.3–2.4; and Lanyu Island: 2.5.

Typhoons Affecting Taiwan: Current Understanding and Future Challenges

Of all the natural disasters occurring in Taiwan, tropical cyclones are the most serious. Over a 20-yr period, Taiwan was hit by an average of 3.7 typhoons per year. These storms can produce heavy rainfall and strong winds, leading to severe damage to agriculture and industry, and serious loss of human life. An outstanding example is Typhoon Herb, which made landfall in Taiwan on 31 July 1996. Typhoon Herb took 70 lives and caused an estimated $5 billion of damage to agriculture and property. Accurate prediction of the track, intensity, precipitation, and strong winds for typhoons affecting Taiwan is not an easy task. The lack of meteorological data over the vast Pacific Ocean and the strong interaction between typhoon circulation and Taiwan's mesoscale Central Mountain range are two major factors that make the forecasting of typhoons in the vicinity of Taiwan highly challenging. Improved understanding of the dynamics of typhoon circulation and their interaction with the Taiwan terrain is needed for more ...