Cool-temperate Species Research Articles

Seasonal phosphorus and nitrogen cycling in four Japanese cool-temperate forest species

PurposeIn plant-soil systems, phosphorus partitioning during the annual cycle related to nitrogen partitioning remains largely unknown. The present study aims at assessing the soil-plant P allocation patterns of four tree species along four phenological stages and its relationship with tissues and soil N concentrations.MethodsCryptomeria japonica, Larix kaempferi, Fagus crenata and Robinia pseudoacacia trees were selected to sample coarse roots, sapwood, foliage, litter and soil during four phenological stages where total and Olsen extractable P and nitrogen content were measured respectively.ResultsIntra- and inter plant tissue nitrogen correlated well with phosphorus during the four phenological stages, especially root nitrogen. Fagus and Robinia were phosphorus limited, Larix was nitrogen limited and Cryptomeria co-limited. All species reabsorbed phosphorus and nitrogen from foliage prior to leaf abscission and stored nitrogen in roots and sapwood. Phosphorus storage was solely found in sapwood of Robinia. Soil dissolved ammonium correlated positively with nitrogen reabsorption efficiency during the green leaf stage, while single soil nutrient variables did not correlate with phosphorus reabsorption efficiency.ConclusionsPlant tissues nitrogen partitioning correlated well with their respective phosphorus partitioning and the increase of soil NH4+ correlated positively with nitrogen reabsorption efficiency, regardless of tree species during the green leaf stage. The results of this study show the intricate relationship that exists between nitrogen and phosphorus in the soil-plant continuum as well as the tree species specific internal cycling of these nutrients.

Recent demographic histories of temperate deciduous trees inferred from microsatellite markers

BackgroundAccurate inference of demographic histories for temperate tree species can aid our understanding of current climate change as a driver of evolution. Microsatellites are more suitable for inferring recent historical events due to their high mutation rates. However, most programs analyzing microsatellite data assume a strict stepwise mutation model (SMM), which could cause false detection of population shrinkage when microsatellite mutation does not follow SMM.ResultsThis study aims to reconstruct the recent demographic histories of five cool-temperate tree species in Eastern Asia, Quercus mongolica, Q. liaotungensis, Juglans cathayensis, J. mandshurica and J. ailantifolia, by using 19 microsatellite markers with two methods considering generalized stepwise mutation model (GSM) (MIGRAINE and VarEff). Both programs revealed that all the five species experienced expansions after the Last Glacial Maximum (LGM). Within butternuts, J. cathayensis experienced a more serious bottleneck than the other species, and within oaks, Q. mongolica showed a moderate increase in population size and remained stable after the expansion. In addition, the point estimates of the multistep mutation proportion in the GSM model (pGSM) for all five species were between 0.50 and 0.65, indicating that when inferring population demographic history of the cool-temperate forest species using microsatellite markers, it is better to assume a GSM rather than a SMM.ConclusionsThis study provides the first direct evidence that five cool-temperate tree species in East Asia have experienced expansions after the LGM with microsatellite data. Considering the mutation model of microsatellite has a vital influence on demographic inference, combining multiple programs such as MIGRAINE and VarEff can effectively reduce errors caused by inappropriate model selection and prior setting.

Southern limits of distribution of the intertidal gobies Chaenogobius annularis and C. gulosus support the existence of a biogeographic boundary in southern Japan (Teleostei, Perciformes, Gobiidae).

Understanding the distributional patterns of individual animal groups with respect to coastal topology and the local physical environment provides essential foundational frameworks for marine zoogeography. In the northwestern Pacific waters of Japan, the distributional pattern of some cool-temperate species of marine fishes suggests the existence of a biogeographic boundary corresponding to a long sandy shore on the eastern coast of Kyushu, southern Japan. The existence of this hypothetical biogeographic boundary was tested by mapping the southern distributional limit of two species of cool-temperate intertidal gobies, Chaenogobius annularis and C. gulosus, which are endemic to East Asia and common in rock pools within their range in the Japanese Archipelago. Distribution and abundance were assessed by survey of museum collections from south-east Kyushu (i.e., the entire coasts of Kagoshima and Miyazaki prefectures); and a quantitative survey of the abundance of these gobies in rock pools at various sites around the hypothesized boundary on the eastern coast of Kyushu, including the subtropical Tanega-shima Island. The museum collection survey showed different distribution patterns between the two species: C. annularis was distributed along the entire coasts of south-east Kyushu including subtropical islands, whereas C. gulosus was distributed along these coasts, including one site on a subtropical island, except for an area south of the hypothesized boundary on the eastern coast of Kyushu. The density and occurrence rates of C. annularis in rock pools decreased with latitude, it being absent from a subtropical island, and C. gulosus was not detected from sites south of the hypothesized boundary. The qualitative survey showed that the southernmost records of C. annularis and C. gulosus were the adjacent subtropical islands (Yaku-shima and Tanega-shima islands respectively), although the quantitative survey suggested that their normal range of distribution was limited to the southern part of the Kyushu mainland. A combination of qualitative and quantitative survey methods in the present study highlighted that the southernmost record of a certain species may not necessarily indicate the true limit of its distribution. The distribution of C. gulosus supports the existence of the hypothetical biogeographic boundary, and the different distribution patterns of the two species may be caused by differences in their early life histories.

Sea surface conditions in the southern Nordic Seas during the Holocene based on dinoflagellate cyst assemblages

Dinoflagellate cyst (dinocyst) records from the southern Nordic Seas were compiled in order to evaluate the evolution of upper ocean conditions, on a millennial timescale and supported by a highly resolved record from the Vøring Plateau. After the transitional phase from the last deglaciation, three main phases define the Holocene. The early Holocene (>7.5 ka BP) features important numbers of cool-temperate species dominated by Nematosphaeropsis labyrinthus and Impagidinium pallidum in the west. The assemblage composition changes drastically at the transition from the early to the mid-Holocene, from when on Operculodinium centrocarpum dominates. The changeover is dated between ~6.1 and 7.5 ka BP, perhaps earlier closer to the Iceland–Scotland Ridge, and appears to be linked to the onset of a modern type of surface circulation. ‘Warmest’ assemblages occur at the Vøring Plateau shortly after the transition, when Atlantic waters also appear to have spread farthest westward. The recurrence of colder elements can be linked to cooling from ~2.4 ka BP at the Vøring Plateau and presumably earlier in the west but is difficult to date there because of the low sedimentation rates. This is a general issue in many areas of the Nordic Seas and appears to have an important effect on cyst concentrations and assemblage composition, with the possible loss of oxygenation-sensitive cysts in the older parts of the cores. Comparing dinocyst-based quantitative reconstructions with those retrieved from other plankton reveals a significantly different trend between proxies, linked to a differing autecological response to seasonal changes at their respective depth habitats.

Distribution ofBucklandiella lamprocarpa(Grimmiaceae, Musci) in South Africa

Abstract Bucklandiella lamprocarpa (Mull.Hal.) Bednarek-Ochyra & Ochyra is the only rheophytic representative of the genus in South Africa. Although this distinct and almost unmistakable species is bipolar in distribution, it is mostly an austral cool-temperate species ranging northwards along the alpine belts of South America and Africa. Examples are given of pan-Holantarctic mosses in the Cape Floristic Region and hypotheses put forward to explain this distribution pattern. The South African distribution of B. lamprocarpa is mapped and described in detail.

Light requirements of Australian tropical vs. cool-temperate rainforest tree species show different relationships with seedling growth and functional traits

A trade-off between shade tolerance and growth in high light is thought to underlie the temporal dynamics of humid forests. On the other hand, it has been suggested that tree species sorting on temperature gradients involves a trade-off between growth rate and cold resistance. Little is known about how these two major trade-offs interact. Seedlings of Australian tropical and cool-temperate rainforest trees were grown in glasshouse environments to compare growth versus shade-tolerance trade-offs in these two assemblages. Biomass distribution, photosynthetic capacity and vessel diameters were measured in order to examine the functional correlates of species differences in light requirements and growth rate. Species light requirements were assessed by field estimation of the light compensation point for stem growth. Light-demanding and shade-tolerant tropical species differed markedly in relative growth rates (RGR), but this trend was less evident among temperate species. This pattern was paralleled by biomass distribution data: specific leaf area (SLA) and leaf area ratio (LAR) of tropical species were significantly positively correlated with compensation points, but not those of cool-temperate species. The relatively slow growth and small SLA and LAR of Tasmanian light-demanders were associated with narrow vessels and low potential sapwood conductivity. The conservative xylem traits, small LAR and modest RGR of Tasmanian light-demanders are consistent with selection for resistance to freeze-thaw embolism, at the expense of growth rate. Whereas competition for light favours rapid growth in light-demanding trees native to environments with warm, frost-free growing seasons, frost resistance may be an equally important determinant of the fitness of light-demanders in cool-temperate rainforest, as seedlings establishing in large openings are exposed to sub-zero temperatures that can occur throughout most of the year.

Nocturnal lizards from a cool-temperate environment have high metabolic rates at low temperatures

Ectotherms from low-temperature environments have higher metabolic rates at low temperatures than those from warm-temperature environments. We predicted that nocturnal lizards, which are active at much lower environmental temperatures than diurnal lizards, would also have higher metabolic rates at low temperatures, and by association a lower thermal sensitivity (Q(10)) than diurnal and crepuscular lizards. We measured the rate of oxygen consumption (VO2) of eight cool-temperate species of lizard (four nocturnal, three diurnal, and one crepuscular) at 13 and 26°C and analyzed log transformations of these data using log mass as a covariate. As expected, VO2 was positively correlated with temperature in all eight species, with VO2 being two to four times higher at 26°C than at 13°C. As predicted, at 13°C (but not 26°C) the VO2 was significantly higher in nocturnal than diurnal lizards. Species-specific differences and mass scaling factors explain the patterns of thermal sensitivity seen among these eight lizard species. Thermal sensitivity is strongly influenced by mass, with smaller species generally having higher thermal sensitivity of their metabolic rate, and this result deserves further exploration among other ectotherms. We conclude that, along with the previously reported lower cost of locomotion found in nocturnal lizards, they also partially offset the thermal handicap of activity at low body temperatures by having an elevated VO2 at lower temperatures.

Dinoflagellate cysts and bloom events at Todos Santos Bay, Baja California, México, 1999–2000

Forty-two species of dinoflagellate motile cells and 18 species of organic-walled dinoflagellate resting cysts were identified in samples collected at Todos Santos Bay, Baja California, México, from September 1999 to June 2000. These temperate to cool-temperate species belong mainly to the families Gonyaulacaceae and Protoperidiniaceae. Lingulodinium polyedrum (Stein, 1883) Dodge 1989 was the dominant species both in the sediments and water column. During this period we observed planktonic motile cells, temporary cysts with cellulose walls, and resting cysts with resistant dinosporin walls. Two dinoflagellate blooms occurred in the spring to summer of 2000 allowing us to observe the timing of cyst production. The temporary cysts appeared between these blooms and also in the summer, whereas the resting cysts appeared during the preceding fall and winter. Resting cysts appeared in colder conditions, whereas the temporary cysts were produced within a particular thermal window and under nutrient depletion. Resting cysts were concentrated in discrete areas at depths of less than 25 m, and associated with sediments ranging from silt to fine sand. These cysts were abundant in the surface sediments during summer, fall and winter, whereas the motile cells dominated during the spring and summer, when the two L. polyedrum blooms were observed. The abundance of cells in the plankton, comprising motile cells and temporary cysts, appears to be inversely proportional to the concentration of resting cysts of the same species in the surface sediments.

Phylogenetic Relationships and Climatic Adaptations in the Drosophila takahashii and montium Species Subgroups

We analyze phylogenetic relationships among temperate, subtropical highland, and subtropical lowland species of the Drosophila takahashii and montium species subgroups based on sequence data of COI and Gpdh genes and discuss the evolution of temperate species in these subgroups with reference to their climatic adaptations. In the takahashii subgroup, D. lutescens (the temperate species) branched off first in the tree based on the combined data set, but D. prostipennis (the subtropical highland species) branched off first in the trees based on single genes. Thus, phylogenetic relationships in this subgroup are still ambiguous. In the montium subgroup, the cool-temperate species are phylogenetically close to the warm-temperate species, and these cool- and warm-temperate species form a cluster with the subtropical highland species. This suggests that perhaps the cool-temperate species derived from the warm-temperate species and the warm-temperate species derived from the subtropical highland species. In comparison with the subtropical lowland species, the subtropical highland species may be better able to colonize temperate areas since, as in the temperate species, they have an ability to develop their ovaries at moderately low temperature. However, the subtropical highland species, as well as the subtropical lowland species, were much less cold tolerant than the temperate species. Therefore, considerable genetic reformation would be required for both the subtropical highland and the subtropical lowland species to adapt to temperate climates.

Heat- and cold-shock responses and temperature adaptations in subtropical and temperate species of Drosophila

Accumulation of Hsp70 mRNA was investigated with relation to heat and cold tolerance in adult males of three Drosophila species. The subtropical lowland species ( D. watanabei) and the cool-temperate species ( D. triauraria) were more tolerant to heat than the subtropical highland species ( D. trapezifrons), and the cool-temperate species were much more tolerant to cold than the two subtropical species. Thus, heat and cold tolerance was related to temperature conditions in the habitats. The threshold temperatures for the induction of Hsp70 mRNA at heat and cold were higher in D. watanabei than in D. trapezifrons or D. triauraria, but were not different between the latter two species in spite of the difference in their heat and cold tolerance. In D. trapezifrons, exposures to 0°C for 12 h and 6°C for 24 h killed about 40% of individuals, but the former treatment induced Hsp70 mRNA while the latter one did not. Thus, the relation between the heat- and cold-shock responses and temperature tolerance was not rigid in the species studied. In D. triauraria, the threshold temperatures for the induction of Hsp70 mRNA at heat and cold were lower when reared at a lower temperature.

Relationship Between Cold Stupor and Cold Tolerance in Drosophila (Diptera: Drosophilidae)

Cold stupor (knock-down temperature) was studied in relation to cold tolerance (lethal temperature) in adult flies of cool-temperate, warm-temperate, and subtropical species belonging to the Drosophila melanogaster species group. Knock-down temperature was strongly correlated with lethal temperature ( r = 0.94). The cool-temperate species had lower knock-down and lethal temperatures, the subtropical species had higher ones, and the warm-temperate species had intermediate ones. Little intraspecific variation was observed in knock-down temperature. In a cool-temperate species, individuals in reproductive diapause had lower knock-down and lethal temperatures than reproducing ones. In addition, knock-down and lethal temperatures were lower in flies reared at a lower temperature. When rearing temperature was shifted, knock-down temperature changed with a logarithmic function of acclimation period. The rate of acclimation did not differ among the cool-temperate, warm-temperate, and subtropical species. Measurements on hybrids between D. lutescens Okada (a warm-temperate species) and D. takahashii Sturtevant (a subtropical species) suggested that loci responsible for the difference in knock-down temperatures between these 2 species were located on both autosome(s) and the X chromosome.

An ecophysiological interpretation of hemoglobin multiplicity in three herbivorous marine teleost species from New Zealand

Hemoglobin components (isohemoglobins) and their isoelectric points (pI) were analysed for three herbivorous marine teleosts, and the functional properties of their unfractionated, stripped hemolysates were determined. Kyphosus sydneyanus and Girella tricuspidata possess six isohemoglobins and share a dominant cathodic band (pI=8.61). Odax pullus possesses four isohemoglobins characterised by two strongly anodic bands (pI=5.80, 4.89). Equilibrium binding studies of the hemolysate complexes from K. sydneyanus and G. tricuspidata revealed high oxygen affinities which were relatively insensitive to pH, whereas oxygen affinity was markedly lower and more pH sensitive in O. pullus. Moreover, hemoglobin-oxygen affinity was less temperature-sensitive in K. sydneyanus than in O. pullus. These observations support the hypothesis that hemoglobin oxygen loading in the cool-temperate species ( O. pullus) may be compromised in the most northerly (warm) limits of its distribution, and that ecologically equivalent species in warmer and thermally variable habitats ( K. sydneyanus and G. tricuspidata) possess more cathodic isohemoglobins which are less influenced by pH and temperature.

Systematics of Nothofagus (Nothofagaceae) based on rDNA spacer sequences (ITS): taxonomic congruence with morphology and plastid sequences

Phylogenetic relationships were examined within the southern beech family Nothofagaceae using 22 species representing the four currently recognized subgenera and related outgroups. Nuclear ribosomal DNA sequences encoding the 5.8s rRNA and two flanking internal transcribed spacers (ITS) provided 95 phylogenetically informative nucleotide sites from a single alignment of ~588 bases per species. Parsimony analysis of this variation produced two equally parsimonious trees supporting four monophyletic groups, which correspond to groups designated by pollen type. These topologies were compared to trees from reanalyses of previously reported rbcL sequences and a modified morphological data set. Results from parsimony analysis of the three data sets were highly congruent, with topological differences restricted to the placement of a few terminal taxa. Combined analysis of molecular and morphological data produced six equally parsimonious trees. The consensus of these trees suggests two basal clades within Nothofagus. Within the larger of the two clades, tropical Nothofagus (subgenus Brassospora) of New Guinea and New Caledonia are strongly supported as sister to cool-temperate species of South America (subgenus Nothofagus). Most of the morphological apomorphies of the cupule, fruit, and pollen of Nothofagus are distributed within this larger clade. An area cladogram based on the consensus of combined data supports three trans-Antarctic relationships, two within pollen groups and one between pollen groups. Fossil data support continuous ancestral distributions for all four pollen groups prior to continental drift; therefore, vicariance adequately explains two of these disjunctions. Extinction of trans-Antarctic sister taxa within formerly widespread pollen groups explains the third disjunction; this results in a biogeographic pattern indicative of phylogenetic relationship not vicariance. For the biogeographically informative vicariant clades, area relationships based on total evidence support the recently advanced hypothesis that New Zealand and Australia share a unique common ancestry. Contrary to previous thought, the distribution of extant Nothofagus is informative on the area relationships of the Southern Hemisphere, once precise phylogenetic relationships are placed in the context of fossil data.

Distribution Patterns of Zooplankton in Tomales Bay, California

Spatial patterns of abundance of the zooplankton of Tomales Bay, California, were studied over one year from August 1987 to September 1988. Samples were taken on six transects up the long axis of the bay, and the species composition and abundance of common species were determined. Distribution patterns were similar to those observed in other estuaries and bays, with species from nearby neritic waters occurring in the outer bay and a few resident species in the inner bay. This pattern may be best explained by size-selective predation within the bay. Most alternative explanations can be ruled out for Tomales Bay, except for possible temperature effects on cool-temperate neritic species. The four common species ofAcartia in Tomales Bay were in two subgenera, each of which included a neritic species and a smaller inner-bay species. The occurrence of the smaller of each pair in the inner bay, which has been observed forAcartia and other species in other estuaries and bays, may also be a result of size-selective predation.

Seasonal changes in glycogen and trehalose content in relation to winter survival of four temperate species of Drosophila

Trehalose was the major sugar found in adult flies of four temperate species of Drosophila (D. subauraria, D. triauraria, D. rufa and D. lutescens) and its level rose in early winter and gradually declined thereafter. Low temperature facilitated trehalose synthesis in these species, but the diapause state did not affect the synthesis, at least in the cool-temperate species ( D. subauraria and D. triauraria). In diapausing individuals of these cool-temperate species, glycogen content remained rather high even in mid-winter, but declined to low levels by spring. By contrast, the warm-temperate species ( D. rufa and D. lutescens) and the non-diapause strain of D. triauraria exposed to a cool-temperate climate lost more than half of their stored glycogen by mid-winter and they did not survive to the spring. It is concluded therefore that glycogen level plays a part in winter survival in these Drosophila species.

Energy storage during reproductive diapause in the Drosophila melanogaster species group.

Temperate species of the Drosophila melanogaster group enter reproductive diapause for overwintering in response to short daylength. During the prediapause period they accumulate triacylglycerols, but not glycogen, as energy resources. The capacity for storing triacylglycerols differs between species, and appears to be closely correlated with diapause and cold-hardiness; cool-temperate species, such as those of the auraria species complex, which enter a deep diapause and are highly cold-hardy, accumulate larger quantities of triacylglycerols than warm-temperate species, such as D. rufa and D. lutescens, which enter a weak diapause and are less cold-hardy. Among the cool-temperate species, D. subauraria occurs at a higher latitude and has the greatest capacity for accumulating triacylglycerols. A subtropical species, D. takahashii, which has no diapause in nature and is not cold-hardy, is unable to store the same quantities of triacylglycerols as temperate species.

Metabolic rate-temperature curves of the horned viper, Cerastes cerastes gasperetti, the moila snake, Malpolon moilensis, and the adder, Virera berus

1. Resting metabolic rates of the horned viper, Cerastes cerastes gasperetti (desert species), the moila snake, Malpolon moilensis (desert species), and the adder, Vipera berus (cool-temperate species) were determined over the body temperature ranging from 5 to 35°C using a double-chamber, volumetric closed system. 2. Resting metabolic rates of sub-adults of C. c. gasperetti and M. moilensis were higher than those of the adults over the temperature range 5–35°C. 3. Resting metabolic rate of V. berus was higher than that of C. cerastes. This may indicate an effect of climate on the energy metabolism of snakes.

Freshwater fishes and plate tectonics in the southwest Pacific

In considering freshwater fishes in the southwest Pacific attention is focussed, fairly obviously, on the Australian and New Zealand regions. The numerous more isolated islands of the area, like New Caledonia, Norfolk and Lord Howe, are largely devoid of freshwater fish species, although New Caledonia has a freshwater-limited galaxiid and Lord Howe has one that is diadromous (i.e. regularly spends a part of its life cycle in the sea). Most of the islands of the southwestern Pacific also have freshwater eels, but these, too, are diadromous. The remaining freshwater fishes of the numerous, mostly tropical islands of the western Pacific are probably of direct marine derivation and are of little interest in a discussion of freshwater fish biogeography. Thus any analysis of the biogeography of fishes of the southwestern Pacific is concerned primarily with the faunas of Australia and New Zealand and their associated islands. Both Australia and New Zealand have small freshwater fish faunas. Australia (including Tasmania) has about 170 species with a further 180 or so in New Guinea. (However, the fauna of New Guinea is poorly known.) New Zealand has only 27 freshwater species. The Australian fauna reveals a broad mixture of relationships. Some ancient forms indicate Pangean or Gondwanian origins with relationships, where understood, in distant and disjunct areas of the globe ( Neoceratodus, Scleropages, Lepidogalaxias). Species with pan-tropical relationships may represent old Gondwanian distributions ( Ophisternum), or alternatively, more recent marine dispersals (ariid catfishes). A significant portion of the fauna has cool southern temperate relationships ( Geotria, Galaxias), many have widespread Indo-Pacific relationships (Gobiidae, Anguillidae, Clupeidae, etc.), while a few have as yet indeterminate relationships (Percichthyidae). The affinities of New Zealand freshwater fishes are divided between warmer Indo-Pacific groups (Eleotridae, Anguilla) and cool couthern temperate groups ( Geotria, Galaxias), both having close Australian relationships, the cool-temperate species also having South American affinities. The older elements, with broad global relationships, demonstrate patterns that may be a product of an ancestral southern continent, but many groups seem likely to have attained their distributions more recently, and to be a product of marine dispersals.

Vegetation in subtropical formosa during the pleistocene glaciations and the holocene

Pollen analyses of three sections in central Taiwan (covering the Early Pleistocene and about the last 60,000 years) show several drastic vegetational changes with climatically (and, later, archaeologically) meaningful variations. A puzzling pollen assemblage, i.e., the boreal conifers ( Abies, Picea, and Tsuga), and pine with pteridophytes, occurred in the Middle Waichiataoan stage (pollen zone W-2 possibly corresponding to the Praetiglian) that succeeded the early warm stage W-1. The Jih Tan core (745.5 m altitude) provides an important example of the Late Pleistocene vegetational history in the subtropics with an absolute chronological scale. The early Tali glacial stage ( T-1) before ca. 60,000 B.P., is characterized by Symplocos, Tsuga chinensis, and Pinus, indicating that the temperature was 5.0–9.0°C cooler than today. The maximal Tali glacial stage ( T-2), from some time subsequent to 60,000–50,000 B.P., contains predominantly the boreal conifers and pine, very low percentages of the temperate elements and plentiful aquatics ( Trapa, Nuphar, and Persicaria). This was the coldest stage throughout the Late Pleistocene with a temperature decrease of 8.0–11.0°C, but nevertheless it permitted the growth of an eutrophic species of Trapa, in Jih-Yueh Tan. The last Tali glacial stage, from ca. 50,000 to 10,000 B.P., is dominated by the cool-temperate species ( Cunninghamia konishii, Quercus, Ulmus, Zelkova, Juglans cathayensis, Ligustrum, and Salix). After the increase of temperature early in thi stage (between 45,000 and 40,000 B.P.), yet colder than the present, a short cooling phase came at around 35,000 B.P. An abundance of aquatic species and the formation of peat in the early Tali glacial time may indicate relatively dry summers, with perhaps a prevailing continental climate. In the Holocene,after about 10,000 B.P., the cool-temperate species were rapidly replaced by such subtropical and warm-temperate species as Mallotus paniculatus, Trema cf. orientalis, Liquidambar formosana, Castanopsis, Umbelliferae A type, and Cyathea. A sudden increase of chenopodiaceous and large-sized gras s pollen grains in both the Jih Tan Tashuiku Tan cores around 4,000 B.P., implies that agricultural activities have been intensified by new settlers from mainland China. A shrubby subtropical species ( Mallotus) shows its peak during the Formosan hypsithermal interval.