Inter-clonal difference in sodium uptake within the speciesphleum pratense andfestuca pratensis

Summary A study was made of intra-species differences in sodium uptake by timothy (Phleum pratense) and meadow fescue (Festuca pratensis), two pasture grasses that are generally known as being low in Na-content compared with perennical ryegrass (Lolium perenne) and cocksfoot (Dactylis glomerata). Na²² was used with NaNO₃ as a tracer in a fertilizer experiment on seedlings grown on trays placed on benches in the greenhouse. With timothy significant clonal differences in Na-uptake varied from one half to the double, but the Na-contents were still appreciably lower than in ryegrass or cocksfoot.     

Screening of Korean marine plants for their inhibitory effect on histamine release from RPMCin vitro

Allergy, meaning ‘heightened reactivity’ of a host on being exposed to an antigen, is an immediate reaction which included anaphylaxis following contact with an antigen. An anaphylatic reaction is caused by the release of pharmacological mediators, like histamine, from mast cells. The potential anti-allergic activities of 27 seaweed and 19 salt marsh extracts collected from the coast of Korea were tested against the inhibition of histamine release in rat peritoneal mast cells (RPMCs). Among them, three salt marsh plants (Persicaria lapathifolia, Ixeris tamagawaensis, andSalsola komarovir) significantly showed more than 75% of inhibition of the histamine release at a concentration of 100 μg/mL, and also three salt marsh (Messerschmidia sibirica, Rosa rugosa, andPortulaca oleraceae) and three seaweed (Colpomenia bullosa, Derbesia marina, andSargassum thunbergii) extracts exhibited moderately inhibition effects when compared to the control.     

Revegetation patterns and seedbank structure on abandoned pastures in northern Japan

To compare revegetation patterns between native and exotic species on abandoned pastures in northern Japan, we surveyed the vegetation structure and the seedbank using a flotation technique in 140 1 1 m plots. Previously introduced grasses such as Poa pratensis, Phleum pratense, and Dactylis glomerata were abundant 20 yr after the pasture abandonment, while Sasa senanensis, native shrub species, regenerated from propagation that had spread from the surrounding forests. S. senanensis shrublands and P. pratensis/P. pratense grasslands established on deep soils while D. glomerata grasslands established on shallow soils. Trees rarely became established on abandoned pastures. The seed density in the seedbank, representing 19 species, ranged from 542 to 2957 seeds/m². The dominant species in the vegetation (P. pratensis, Trifolium repens, and Rumex acetosella) were also common in the seedbank, whereas Cerastium holosteoides var. angustifolium, Chenopodium album var. centrorubrum, and Erigeron canadensis were widespread in the seedbank but did not occur in the extant vegetation. S. senanensis regenerated by vegetative propagation, and P. pratensis and P. pratense developed a seedbank. We concluded that for native species, particularly S. senanensis, vegetative reproduction has an important role on revegetation rather than regeneration from the seedbank, and the dwarf bamboo may be a keystone species in the ecosystems.     

Flowering phenology and survival of two annual plants <Emphasis Type="Italic">Impatiens noli-tangere</Emphasis> and <Emphasis Type="Italic">Persicaria thunbergii</Emphasis> co-occurring in streamside environments

Flowering phenology of cleistogamous annual plants Impatiens noli-tangere and Persicaria thunbergii was studied with reference to their mortality in streamside environments in northern Japan. I. noli-tangere produced flower-buds and flowers from late June to October, whereas P. thunbergii did so from mid-August to October. Both species were often killed by rapid current and submergence after heavy rainfall, which was unpredictable in the timing and intensity. P. thunbergii was more tolerant to rapid current and submergence than I. noli-tangere. Some individuals of I. noli-tangere were killed by herbivory from sawfly larvae in summer, but P. thunbergii individuals were seldom killed by herbivory. In consequence, the percentage of individuals that survived until the end of September was higher in P. thunbergii than in I. noli-tangere. These situations are assumed to select a long reproductive life in I. noli-tangere and autumn flowering in P. thunbergii.     

Seed dormancy/germination traits of seven Persicaria species and their implication in soil seed-bank strategy

In order to predict species-specific potential to form persistent soil seed-banks and to characterize the dynamics of their seed-banks, the seed dormancy/germination traits of seven Persicaria (Polygonum s.lat.) species sharing lakeshore habitats in central Japan were examined. Strict light requirements for seed germination were not observed in any of the species examined. Although all species required moist chilling (0–6 weeks) to break seed dormancy and were sensitive to temperature fluctuation, the degree of both responses varied between species. Seed germination of Persicaria hydropiper (L.) Spach, Persicaria lapathifolia (L.) S.F. Gray, and Persicaria longiseta (De Bruyn) Kitag. was more accelerated by temperature fluctuation and required shorter chilling periods compared with Persicaria japonica (Meisn.) H. Gross, Persicaria maackiana (Regel) Nakai, Persicaria thunbergii (Sieb. et Zucc.) H. Gross, and Persicaria sieboldi (Maisn.) Onki. Secondary dormancy was induced in all species at higher temperatures (24 and 30°C). A persistent seed-bank strategy suggested by the dormancy/germination traits of the studied species was also demonstrated by seedling emergence from surface soils collected from the natural habitat immediately before seed dispersal, as well as by viable seed persistence for 13 months in the field in a seed burial experiment. In the natural habitat, the species with longer chilling requirements occurred in various microhabitats, including the interior of moist tall grasslands, whereas the species having higher sensitivity to temperature fluctuation were most frequently found in sparsely vegetated microhabitats.     

The differential mortality ofTrifolium repens andPhleum pratense seedlings in relation to temperature

Summary 1. The pathogenic potential of test soils towards germinating seeds ofTrifolium repens andPhleum pratense showed marked variation with time, but no apparent relation to seasonal changes or to the condition of the soil.2. The two species differed in their response to pathogenic factors and the ratioT. repens :P. pratense in the seedlings which emerged showed marked variation.3. Both pre- and post-emergence mortality ofT. repens occurred, whileP. pratense responded to low soil temperature mainly by failure to germinate, through death, and more often enforced dormancy of the seed.4. Chilling the seed in wet soil before germination increased mortality considerably.P. pratense stands were reduced at temperatures below 10°C. Losses ofT. repens were small above 5°C, but at 0°C and below losses were heavier than ofP. pratense.5. In sterilised soil, establishment was consistently better than in corresponding unsterilised soils. Fungicide treatment of the seed in unsterilised soil resulted in improvement of stands in most cases, but less than soil sterilisation.6. The improvement in emergence due to soil sterilisation or fungicide treatment was much the same after all pre-chilling treatments.7. The relationship of germination behaviour and liability to pathogenic attack under different temperature conditions is discussed in the light of experience in the field.     

Cocoon production,morphology, hatching pattern and fecundity in seven tropical earthworm species — a laboratory-based investigation

Data on the reproductive biology of seven Indian species of earthworms, viz.Perionyx excavatus Perrier,Lampito mauritii Kinberg,Polypheretima elongata (Perrier),Pontoscolex corethrurus (Muller),Eutyphoeus gammiei (Beddard),Dichogaster modiglianii (Rosa) andDrawida nepalensis Michaelsen are presented. The peregrine earthworms such asPerionyx excavatus, Pontoscolex corethrurus, Dichogaster modiglianii, andPolypheretima elongata are considered to be continuous breeders with high fecundity. NativeLampito mauritii andDrawida nepalensis are semi-continuous andEutyphoeus gammiei discrete breeders. There is a dramatic increase in cocoon production by most earthworm species of Tripura in the summer and monsoon with a corresponding peak during April and July. Cocoon production decreased or ceased during winter. Temperature affected the incubation period of cocoons. With increase in temperature, incubation period increased in the endogeic worms,Pontoscolex corethrurus, Polypheretima elongata andDrawida nepalensis and decreased in the epigeic worms,Perionyx excavatus andDichogaster modiglianii, within a temperature range between 28–32°C under laboratory conditions. There was a significant(P < 0.05) positive correlation between number of hatchlings per cocoon and incubation period inLampito mauritii. High rate of cocoon production, short development time with high hatching success, as well as continuous breeding strategies in the epigeic speciesPerionyx excavatus andDichogaster modiglianii and the top soil endogeic species,Pontoscolex corethrurus,Drawida nepalensis andLampito mauritii, indicate their possible usefulness in vermiculture. The giant anecic worm,Eutyphoeus gammiei, which has a very long cocoon development time, discrete breeding strategy and very low rate of cocoon production, is not a suitable species for vermiculture.     

Testing the moss layer transfer technique on mineral well pads constructed in peatlands

Peatlands are abundant in the boreal region of Canada but little is known about their restoration on oil sands well pads. The goal of this study is to compare the reintroduction of different peatland plant communities and substrate amendments/decompaction in order to rehabilitate peatland vegetation on former in situ well pads constructed in wetlands. One field experiment tested which peatland plant communities (Shrubby Rich Fen, Treed Rich Fen) would best colonize different substrates (sawdust, clay loam, mix sawdust-clay, peat, surface roughness). We found that the moss layer transfer technique (MLTT) facilitated the establishment of peatland communities on residual mineral soil used to construct the pad, when shaved back to an average water level of the surrounding wetland. The choice of peatland plant community is key to the introduction of bryophytes. Peat amendment facilitated the establishment of plants, whereas soil decompaction had no effect. The MLTT is a promising approach to restore fen plants on well pads. We recommend a scale-up experiment for a whole well site to test the validity of MLTT along different pad removal techniques.     

Difference of invasion behavior between two climax species,Castanopsis cuspidata var.sieboldii andMechilus thunbergii,on lava flows on Miyakejima,Japan

The invasion behavior of two climax species,Machilus thunbergii Sieb. et Zucc. andCastanopsis cuspidata (Thunb.) Schottky var.sieboldii (Makino) Nakai, was studied on the 1874 and 1962 lava flows on Miyakejima, Japan. On the 1962 lava, zoochorousM. thunbergii appeared almost only under crowns of pioneeringAlnus sieboldiana Matsum, while bolochorousC. cuspidata var.sieboldii occurred only along the borders of the lava. The three species,A. sieboldiana, M. thunbergii andC. cuspidata var.sieboldii, corresponded, in order, to the temporal sequence of invasion in the boundary forest and the spatial sequence from margin to center on the 1962 lava. Seed or fruit dispersion is important in primary succession in the case of large disturbances.     

Factors Affecting Proximity Among Members of a Wild Group of Moor Macaques During Feeding,Moving, and Resting

We studied the effects of kinship, age, sex, and other factors on patterns of spatial proximity among group members in a wild group of moor macaques (Macaca maurus) in Sulawesi, Indonesia. We assessed the importance of each factor via multiple linear regression analyses. Moor macaques stay close to their matrilineal relatives more frequently when the group moves or rests than when they feed. Subjects of similar age, sex, or rank tended to stay close to each other. Females were in the proximity of females with newborn infants regardless of the phase of activity of the group. Kinship may have less effect on proximity during feeding in moor macaques than in Japanese macaques. Weak effects of kinship during feeding may result from weak contest competition for food within the group.     

Stellaria nemorum L. andS. montana Pierrat (Caryophyllaceae) in the Forest Communities of Slovenia

Morphological and coenological differences between closely related speciesStellaria nemorum L. andS. montana Pierrat are described.Stellaria montana is frequent in Slovenia and occurs mostly in the montane belt (altitude 600–1200 m). It has been recorded in thirty two forest communities (associations or lower syntaxa). Although widely distributed in EuropeS. nemorum is more rare in Slovenia. It occurs mostly in upper-montane (altimontane) and subalpine belt (altitude 1200–1600 m) in ten forest or shrubby communities. Both,S. nemorum andS. montana are valuable diagnostic species for certain associations. They characterize sites with fresh soil, rich in nitrogen. As an example we present two syntaxa of beech forests of Slovenia, in which the species of theS. nemorum group have high constancy and cover value.     

Peatland establishment on mineral soils: Effects of water level, amendments, and species after two growing seasons

Recent surveys of peatland initiation that occurred over the past 10,000 years in northeastern Alberta have revealed that most peatlands initiated by paludification, or swamping of upland soils. Peatland ecologists have long known the importance of the paludification process, but it has not been transferred to peatland restoration methodologies. We initiated this study to determine if wetland structure and function could be re-established on two well sites established with mineral fill within a peatland complex. At two well sites near Peace River, AB, the mineral material was lowered to near the water level of the surrounding peatland. We placed 288 plots of 2 m × 2 m in size using a series of fertilizer, water level, cultivation, and amendment treatments and then introduced a suite of wetland plants. Four questions are addressed: - (1) Will locally available peatland vascular plant species establish on these wet, compacted, mineral soils? If so: (2) are species responses affected by these treatments? (3) are plants that we did not introduce in the planting regime (weeds) a concern? and (4) will the surrounding bog water chemistry have an effect on water in contact with mineral soils? Results after two growing seasons are - (1) Carex aquatilis and Salix lutea have all successfully established at both well sites; (2) C. aquatilis plants (ramets) have increased to an average of 58.5 per plot, up from the 16 original genets planted; (3) the plant responses to amendments are not significantly different from the control plots; (4) weed abundance is significantly different among some amendment types; and (5) pad ditch water chemistry is affected by the surrounding bog waters.     

Characterisation of extracellular polysaccharides from suspension cultures of members of the Poaceae

Microscopic examination of suspension- cultured cells of Phleum pratense L., Panicum miliaceum L., Phalarisaquatica L. and Oryza sativa L. showed that they were comprised of numerous root primordia. Polysaccharides secreted by these suspension cultures contained glycosyl linkages consistent with the presence of high proportions of root mucilage-like polysaccharides. In contrast, suspension-cultured cells of Hordeum vulgare L. contained mostly undifferentiated cells more typical of plant cells in suspension culture. The polysaccharides secreted by H. vulgare cultures contained mostly linkages consistent with the presence of glucuronoarabinoxylan. The soluble polymers secreted by cell-suspension cultures of Phleum pratense contained 70% carbohydrate, 14% protein and 6% inorganic material. The extracellular polysaccharides were separated into four fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7.0. From glycosyl-linkage analyses, five polysaccharides were identified: an arabinosylated xyloglucan (comprising 20% of the total polysaccharide), a glucomannan (6%), a type-II arabinogalactan (an arabinogalactan-protein; 7%), an acidic xylan (3%), and a root-slime-like polysaccharide, which contained features of type-II arabinogalactans and glucuronomannans (65%). Received: 27 April 1999 / Accepted: 5 June 1999     

Identification of genes involved in a water stress response in timothy and mapping of orthologous loci in perennial ryegrass

In order to characterize the response of selected grasses to water stress, relative water content (RWC) in leaves and quantum efficiency of photosystem 2 (F_v/F_m) were measured in Phleum pratense L., P. bertolonii DC. and P. phleoides H. Karst. during 6 d of water stress. The results indicated differential responses to water stress among the three Phleum species with higher water deficit sensitivity of P. pratense and P. bertolonii than that of P. phleoides. The cDNA-amplified fragment length polymorphism (cDNA-AFLP) technique was applied to identify differentially expressed genes responding to water stress in P. pratense. Cloned and sequenced differentially expressed fragments (DEFs) were used for primer design in order to identify orthologous genes in Lolium perenne L. Twelve genes orthologous to P. pratense DEFs were mapped in the L. perenne mapping population VrnA based on a high resolution melting curve analysis (HRM). This study provides genomic information about 29 differentially expressed genes after water stress in P. pratense and reports on the identification and mapping of twelve orthologs in L. perenne.     

Holocene sedimentary history of some coastal plains in Hokkaido,Japan IV. Diatom assemblages in the sediments from Kushiro moor (2)

Diatom assemblages of sediments obtained from three sites on Kushiro Moor were analyzed to investigate the Holocene sedimentary history. The results showed that: 1) The Takkobu site was originally at the bottom of the paleo-Kushiro Bay, and after-wards the paleo-Takkobu Lagoon developed, became sealed off, and changed to a freshwater lake. The succession to peat moor probably began about 2000 yr B.P. at the Takkobu site. 2) The Tsurui site was originally at the bottom of the paleo-Kushiro Bay, then changed to the paleo-Kushiro Lagoon and became peat moor as a result of the first Holocene regression, which finished about 3600 yr B.P. The site then returned to a brackish lake again, probably due to the second Holocene transgression between 3600 and 3000 yr B.P., thereafter passing through brackish lake and freshwater lake stages, and eventually becaming peat moor at about 2000 yr B.P., 3) At the Chuo site, the second paleo-Kushiro Bay developed again as a result of the second Holocene transgression, which finished about 3000 yr B.P. Thereafter, brackish or freshwater lakes, rivers, and then peat moor developed in the central area of Kushiro Moor. 4) The second marine diatom zone (MD₂ Zone), which indicates the second Holocene transgression, complete by about 3000 yr B.P., is detected only at the Chuo site in the central area of Kushiro Moor.     

Seasonal change in the redox property of peat and its relation to vegetation in a system of floating mat and pond

A relationship was sought between species distribution and seasonal change in the redox property of peat in a floating mat in Mizorogaike Pond, central Japan. The mat surface experienced an annual submergence-emergence cycle due to its sinking-rising movement. Redox potential (Eh) of the surface peat showed little difference between communities in the mat in the submergence season (January–June) and early emergence season (July–August). However variation in Eh among communities was clear in the late emergence season (September–December). Among seven communities in the floating mat, theMenyanthes trifoliata-Rhynchospora fauriei, M. trifoliata-Eriocaulon sikokianum-E. bondoense f.pilosum, Sphagnum cuspidatum andM. trifoliata-Carex thunbergii communities had high Eh (400–600 mV) in the late emergence season, while theMenyanthes trifoliata andPhragmites australis-M. trifoliata communities had lower Eh (200–400 mV). TheM. trifoliata-Isachné globosa community was intermediate (300–500 mV). The earlier the emergence of the peat surface began, the higher the Eh became in the late emergence season.     

Elevational Variation of Leaf Traits in Montane Rain Forest Tree Species at La Chinantla, Southern México1

Variation in leaf traits of dominant tree species in six montane rain forest communities was analyzed along an elevational gradient ranging from 1220 to 2560 m within a single basin at La Chinantla, Oaxaca, México. Three groups of characters were used: morphological (leaf shape, margin, blade configuration, and phyllotaxy), morphometric (leaf area, leaf mass per area, stomatal density, and blade length/width ratio), and anatomical (thicknesses of blade, palisade [PP], and spongy [SP] parenchymae, PP/SP ratio, and epidermis and cuticle thicknesses). The variation of morphological characteristics was only evident at the highest elevations; in contrast, thickness of leaf blade, PP, SP, as well as leaf mass per area clearly increased along the gradient, whereas leaf area was the only variable that significantly decreased with elevation. Thicknesses of epidermis and of the two cuticles were not significantly correlated with elevation. A classification analysis based on a leaf trait matrix led to the distinction between low and high elevation communities, with an approximate limit between them at ca 2300 to 2400 m. The results are discussed in light of environmental changes occurring along elevational gradients. Leaf characteristics of montane rain forest plants offer important insights about the complex roles of abiotic factors operating in these environments and supplement the traditional physiognomic classification schemes for these communities.     

Seedling establishment ofCastanopsis cuspidata var.sieboldii andPersea thunbergii on lava and scoria of the 1962 eruption on Miyake-jima Island,the Izu Islands

Seedling establishment ofCastanopsis cuspidata var.sieboldii Nakai andPersea thunbergii Kosterm. (Machilus thunbergii Sieb. et Zucc.) in early succession was studied on the lava and the scoria of the 1962 eruption on Miyake-jima Island of the Izu Islands. While tall individuals (> 1 m) ofP. thunbergii were found on both the lava and the scoria, those ofC. cuspidata (> 1 m) were found only on the lava. The height growth rate ofC. cuspidata was very low on the scoria, and there was no individual ofC. cuspidata taller than 0.4 m on the scoria. The proportion of yellow leaved individuals was much higher (37.1%) inC. cuspidata than inP. thunbergii (4.0%) on the scoria, while it was similar between the two species on the lava.Persea thunbergii seemed to be able to establish on both the lava and the scoria, butC. cuspidata established only on the lava. The differences in growth rate and vigor between the two species on the lava and the scoria in early succession may influence later stages of succession.     

Occupational strategy of <Emphasis Type="Italic">Persicaria thunbergii</Emphasis> in riparian area: Rapid recovery after harsh flooding disturbance

Persicaria thunbergii is a representative annual herb in Korean wetlands, widely inhabits not only in lentic wetlands, but also in unstable riparian wetlands. To better understand the occupational strategy of this plant, we investigated environment, growth characteristics before and after harsh flooding disturbance in FDA (flooding disturbed area) and NDA (non-disturbed area). Water level, fresh soil moisture and organic matter of NDA were significantly higher than FDA. Before flooding disturbance, plant height, individual length, number of node, individual biomass and biomass per 1 m² were significantly higher in FDA than in NDA. After flooding disturbance, plant height, biomass per 1 m², coverage and relative coverage were significantly lower in FDA than in NDA, yet individual length, number of node, individual biomass and aerial seed production were not different. In FDA, creeping stems survive despite a flooding disturbance because they are parallel with the water flow and are firmly fixed to the ground through numerous adventitious roots. Surviving creeping stems make new shoots rapidly and P. thunbergii recovers its biomass during less than a month. Every regenerated shoots make reproductive organs. Thus, P. thunbergii can reproduce and successfully survive the next generation in the riparian habitat despite the harsh flooding disturbance every year.     

Using palaeoecology to support blanket peatland management

Many peatlands have a recent history of being degraded by extraction, drainage, burning, overgrazing and atmospheric pollution often leading to erosion and loss of peat mass. Restoration schemes have been implemented aimed at rewetting peatlands, encouraging revegetation of bare peat or shifting the present vegetation assemblage to an alternative. Here we demonstrate the use of palaeoecological techniques that allow reconstruction of the historical development of a blanket peatland and provide a historical context from which legitimate restoration targets can be determined and supported. We demonstrate the applicability of simple stratigraphic techniques to provide a catchment-wide peatland development history and reinforce this with a detailed macrofossil reconstruction from a central core. Analysis at Keighley Moor Reservoir Catchment in northern England showed that the present vegetation state was ‘atypical’ and has been characteristic for only the last c. 100 years. Sphagnum moss was an important historic contributor to the vegetation cover between 1500 years ago and the early 1900s. Until the early 1900s Sphagnum occurrence fluctuated with evidence of fire, routinely returning after fire demonstrating good resilience of the ecosystem. However, from the turn of the 20th century, Sphagnum levels declined severely, coincident initially with a wildfire event but remaining extremely diminished as the site regularly underwent managed burning to support grouse moor gun sports where practitioners prefer a dominant cover of heather. It is suggested that any intention to alter land management at the site to raise water tables and encourage greater Sphagnum abundance is in line with peatland development at the site over the past 1500 years. Similar palaeoecological studies providing historical context could provide support for restoration targets and changes to peatland management practice for sites globally.