Cool-temperate Climate Research Articles

Beneficial Effects of Temperate Forage Legumes that Contain Condensed Tannins

The two temperate forage legumes containing condensed tannins (CT) that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT) and sainfoin (Onobrychis viciifolia Scop.; SF). Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kg−1 dry matter (DM), while SF contains 30 to 80 g·CT·kg−1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb.) Dumort.) forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity.

Sub-zero cold tolerance of Spartina pectinata (prairie cordgrass) and Miscanthus × giganteus: candidate bioenergy crops for cool temperate climates.

Miscanthus × giganteus grown in cool temperate regions of North America and Europe can exhibit severe mortality in the year after planting, and poor frost tolerance of leaves. Spartina pectinata (prairie cordgrass), a productive C4 perennial grass native to North America, has been suggested as an alternative biofuel feedstock for colder regions; however, its cold tolerance relative to M. × giganteus is uncertain. Here, we compare the cold tolerance thresholds for winter-dormant rhizomes and spring/summer leaves of M. × giganteus and three accessions of S. pectinata. All genotypes were planted at a field site in Ontario, Canada. In November and February, the temperatures corresponding to 50% rhizome mortality (LT(50)) were near -24°C for S. pectinata and -4°C for M. × giganteus. In late April, the LT50 of rhizomes rose to -10°C for S. pectinata but remained near -4°C for M. × giganteus. Twenty percent of the M. × giganteus rhizomes collected in late April were dead while S. pectinata rhizomes showed no signs of winter injury. Photosynthesis and electrolyte leakage measurements in spring and summer demonstrate that S. pectinata leaves have greater frost tolerance in the field. For example, S. pectinata leaves remained viable above -9°C while the mortality threshold was near -5°C for M. × giganteus. These results indicate M. × giganteus will be unsuitable for production in continental interiors of cool-temperate climate zones unless freezing and frost tolerance are improved. By contrast, S. pectinata has the freezing and frost tolerance required for a higher-latitude bioenergy crop.

Towards making willows potential bio-resources in the South: Northern Salix hybrids can cope with warm and dry climate when irrigated

Willow (Salix spp.) is an attractive biomass resource for many regions, but is today grown commercially mainly in cool-temperate areas. It is unclear whether modern willow hybrids bred for cool-temperate climate are capable of regulating strong water losses when exposed to warm and/or dry climate. The objective was to assess leaf scale water relations (evapotranspiration, E; and stomatal conductance, GS) and corresponding leaf traits in six wild and hybrid willows field-grown in Central Sweden (cool and well-watered), Northern Portugal (warm and dry), and Northern Italy (warm and well-watered). Diurnal courses of E, GS and leaf temperature were recorded, plant heights measured, and leaves sampled for assessment of specific leaf area (SLA) and area-based leaf N content (Na). Height growth, GS, SLA and Na varied between the genotypes, but genotype environment interaction was important only for plant height and GS. Thus, genotypic variation in leaf scale E was mostly caused by stomatal (GS) and not by non-stomatal (leaf temperature) genotypic variation. Leaf scale E was positively correlated with Na when assessed across the drought gradient. It is concluded that the willow hybrids bred for cool-temperate climate (in Scandinavia) are capable of regulating strong water losses when exposed to warm and/or dry climate (in Southern Europe), provided that water supply is good. The ability to regulate water losses under warm and dry conditions in the short term is a pre-condition to high water use efficiency and improved growth in warm and dry environments also in the long term.

Demand and Supply of Water for Agriculture: Influence of Topography and Climate in Pre-Alpine, Mesoscale Catchments

With climate change, water may become limited for intensive agriculture even in regions presently considered “water-rich”. Information about the potential water requirement and its temporal and spatial variability can help to develop future water management plans. A case study was carried out for Switzerland with its highly complex pre-alpine topography and steep gradients in climate. The hydrological model WaSiM-ETH was used to simulate net irrigation requirement (NIR) for cropland, grassland and orchards using criteria to define irrigation periods based either on the water stress level (expressed by the ratio of actual (aET) to potential evapotranspiration ((pET) (Method 1) or on thresholds for soil water potential (Method 2). Simulations for selected catchments were carried out with a daily time step for the period 1981-2010 using a 500 × 500 m spatial resolution. Catchment-scale NIR ranged between 0 and 4.3 million m3 and 0 and 7.3 million m3 for the two methods, respectively, with no trend over the observation period in any catchment. During the heat wave in 2003, NIR increased by a factor of 1.5 to 2.3 relative to the mean, and in catchments where discharge is directly dependent on precipitation, NIR in the summer of 2003 reached the limits of river water availability. In contrast, in a region with water supply from glacier melt water, highest NIR in 2003 still remained far below total river discharge. The results show that NIR varies strongly between years and across the landscape, and even in a presently cool-temperate climate, irrigation may put pressure on regional water resources under extreme climatic conditions that may become more frequent by the end of the 21st century.

A decade of change in the saproxylic beetle fauna of eucalypt logs in the Warra long-term log-decay experiment, Tasmania. 1. Description of the fauna and seasonality patterns

The first decade of sequential and cyclical sampling of saproxylic beetles by means of eclector traps on 12 freshly-felled Eucalyptus obliqua logs at Warra, Tasmania has allowed documentation of a taxonomically and ecologically diverse fauna present in such logs in their early decompositional state. About half of all species are apparently undescribed—a much higher proportion than in most temperate regions. The distribution of individuals among species is typically skewed, with most species being rare and few being common. Neither obligately nor facultatively saproxylic beetles dominate the fauna, but predators predominate over other larval feeding guilds, and—in accordance with ecological theory for early successional habitats—winged species predominate over functionally flightless species. There is some suggestion that trophic structure changed over the period of the study, with the proportion of functionally flightless species increasing. The fauna shows strong seasonality. While the summer months represent the peak of occurrence for most species (in keeping with the cool-temperate climate), every month has its own particular complement of species, such that a strong seasonal cycle in assemblage composition is apparent throughout the year. The timings of emergence peaks vary among the years represented in this study by up to 2 months, with the year of latest emergence corresponding to that with the lowest mean annual maximum temperature; no signature of climate change is evident in the data-set.

Constraints to achieving high potential yield of wheat in a temperate, high-rainfall environment in south-eastern Australia

Average wheat yields in the high-rainfall zone (HRZ) of southern Australia are predicted to be around 10 t ha–1, yet most regions fall short through a lack of locally adapted cultivars or abiotic stress that constrains yield. Wheat yields in Tasmania can be variable but have exceeded this potential yield in some field trials and have thus approached that of other traditionally high-yielding HRZ environments such as northern Europe. A contributing factor to high wheat yields in Tasmania is the cool-temperate climate, which tends not to have extremes in temperature (cold, heat) as may be experienced in HRZ environments elsewhere. Hence an understanding of crop growth, development and yield of wheat of locally adapted wheat cultivars in Tasmania may improve our understanding of the basis of yield formation in other HRZ in Australia. This was evaluated by conducting an analysis for adaptive response of grain yield in 10 wheat genotypes to a range of 14 environments that were favourable for wheat production or experienced constraints to growth. Crop growth and yield formation was then examined in detail for all or a subset of these genotypes in three field trials with contrasting environments, two of which included a time of sowing (TOS) treatment. Environment accounted for around 90% of the sum of squares (SS) in the multi-site analysis of yield. Six environment groups were identified using cluster analysis, two of which were clearly separated in response to frost at flowering or putative biotic stress, which constrained yield to 1.8 and 6.8 t ha–1, respectively. Waterlogging was also a significant abiotic stress in one of the TOS field trials. The late-flowering cultivar Tennant had the highest yield in the presence of waterlogging and by avoiding frost at flowering, although it suffered a yield penalty of 35 and 66%, respectively, compared with the average across environments. The highest-yielding genotypes averaged 8 t ha–1 across environments and included Alberic, the breeding line K37.18 and the new release Revenue. In the detailed experiments on crop growth and development, high grain yields of 10 t ha–1 in Mackellar appeared to be due to increased grains ear–1, resistance to barley yellow dwarf virus and possibly higher radiation-use efficiency, although the latter needs to be confirmed. There was little genotype × environment interaction for grain yield, hence wheat breeders can have a relatively high level of confidence that genetic material with high yield potential should rank consistently across Tasmanian environments. Results presented in the paper will be useful in developing management and breeding strategies to increase potential yield across the HRZ of southern Australia.

Costs of improving the thermal performance of houses in a cool-temperate climate

To minimize the energy needed to heat and/or cool houses, the Building Code of Australia requires that new houses meet a minimum level of thermal performance. A star rating system is used to indicate the level of thermal performance a house achieves. Ratings range from 0 to 10 stars. Theoretically, the more stars, the less the energy required for space heating and/or cooling. Currently, most states and territories in Australia require a minimum 5 star performance. However, a minimum 7–8 star rating is likely in the near future. This article examines the capital cost and design implications of significantly improving the thermal performance of brick veneer houses in a cool-temperate climate. The results show that the cost of achieving a certain level of thermal performance varies significantly depending on the methods and materials used, although improvements in thermal performance can be made for little or no cost.

The Importance of Litter Biomass in Estimating Soil Organic Carbon Pools in Natural Forests of Taiwan

Litter layers store a significant reservoir of carbon in forest ecosystems and are prone to be impacted by climate change and anthropogenic management practices. However, estimating forest litter biomass is commonly neglected in soil surveys. In this study, litter biomass, soil bulk density, fine soil content, and C concentration of the top 20 cm of topsoils were analyzed for 8 natural forests at elevations ranging 390~3000 m located within 4 climate zones (tropical, subtropical, temperate, and cool-temperate climate) to understand the importance of forest litter biomass in estimating soil organic carbon (SOC) pools in Taiwan. Natural temperate forests at high elevations stored 2~3 times the C per hectare than did warm tropical and subtropical ones. The proportion of the litter C pool in topsoils increased with elevation and was highest in the temperate forest (28.8%) and lowest in the tropical forest (4.0%). These results suggest that when estimating the potential of forest C sequestraion and release, temperate and cool-temperate forest litter layers should be of great concern since these C pools are considerably less well protected. The warmth index (WI) was significant positively correlated with litter C pools and SOC stocks (R=0.95), while there was no correlation between the annual precipitation and litter and SOC pools, indicating that litter accumulation and the SOC content in Taiwan are mainly controlled by temperature rather than precipitation.

Restoration of semi-natural forest after clearcutting of conifer plantations in Japan

We reviewed recent studies on the restoration of semi-natural forests after clearcutting of conifer plantations with specific reference to the importance of setting restoration goals, general and specific factors influencing restoration, and the prediction and judgment of successful restoration. For the restoration of semi-natural forests following the clearcutting of conifer plantations, recovery levels and appropriate restoration methods cannot be considered separately from the aims of restoration to provide ecosystem services. Restoration needs to be based on the setting of goals that correspond to the type and degree of ecosystem services targeted. When we aim to restore vegetation dominated by late-seral canopy trees within as short a period after the clearcutting of conifer plantations as possible, advanced regeneration in the pre-logged plantation is the most important and reliable source of post-logging regeneration, just as it is in the recovery of disturbed non-plantation forests. Advanced regeneration is not always present in plantations. Seedling establishment by seed rain from adjacent natural forest patches after a disturbance can contribute to late-seral or canopy species; however, the range of the edge effect is generally short, and the degree of the edge effect depends on the natural forest type and is more pronounced in deciduous forests, such as those in cool-temperate climates, or in forests with a complex forest structure. Thus, advanced regeneration is a better predictor of short-term forest recovery than measures based on seed rain from adjacent seed sources. However, restoration achieved only through advanced regeneration can simplify the species composition, and the recolonization processes of gradual species accession from seeds should be considered in the long-term context of restoration.

Reconstructing the palaeoenvironments of the early Pleistocene mammal faunas from the pollen preserved on fossil bones

We carried out a systematic investigation on the pollen content of sediment adhering to skeletal elements of large mammals which originate from the long lacustrine record of Leffe (Early Pleistocene of the Italian Alps). Three local faunas were discovered during mining activities along the intermediate part (spanning from 1.5 to 0.95 Ma) of the basin succession. The excellent pollen preservation allowed testing the reproducibility of the pollen signal from single skeletons. A clear palaeoenvironmental patterning, consistent with the ecological preferences of the considered mammal species, emerged from the canonical correspondence analysis of pollen types diagnostic for vegetation communities. Edaphic factors related to seasonal river activity changes and to the development of swamp forests in the riverbanks are significantly associated to the occurrences of Hippopotamus cf. antiquus, whereas finds of Mammuthus meridionalis belong to fully forested landscapes dominated by conifer or mixed forests of oceanic, warm to cool-temperate climate. Rhinoceros habitats include variable forest cover under different climate states. Distinct cool-temperate, partially open vegetation could be recognized for large deer included Cervalces cf carnutorum. A palynostratigraphic correlation between individual spectra and a reference palynostratigraphic record allowed assignment of many fossil remains to a precise stratigraphic position. This procedure also shown that the Leffe local faunas include specimens accumulated under different environmental and climate states, as a consequence of high-frequency climate changes characterizing the Late Villafranchian Early Pleistocene.

Root survival of six cool-temperate wetland graminoids in autumn and early winter

Background: Timing of leaf senescence is an important ecological trait of species in cool-temperate climates. In contrast to above-ground biomass, not much is known about timing and extent of root mortality of herbaceous perennials at the end of the growing season. Aims: We undertook to assess patterns of end-of-season root mortality in species of temperate wetlands, investigate if the interspecific variation in the pattern of leaf senescence in autumn is reflected in patterns of root mortality, and determine if coarse axile roots and fine lateral roots differ in their autumn mortality pattern in wetland graminoids. Methods: For six cool-temperate perennial wetland graminoids, we assessed whether their roots die back for the winter, if the species-specific timing of senescence corresponds to interspecific variation in leaf senescence, and if fine lateral roots and axile roots differ in their mortality pattern. Survival and mortality of lateral and axile roots, and above-ground senescence was assessed in Sudbury, Ontario, Canada, from 11 September to 11 December, 2007, a period during which most of the above-ground biomass died. Root mortality was assessed using 2,3,5-triphenyltetrazolium chloride. Results: In Carex oligosperma, Carex stricta, Phalaris arundinacea and Scirpus microcarpus the majority of lateral and axile roots showed little mortality until mid-December. Axile roots of Dulichium arundinaceum showed little mortality, but its lateral roots died in October. Both lateral and axile roots of Sparganium androcladum died in October. Conclusions: These results indicate that fine roots of many species do not senesce along with the leaves for winter in cool-temperate climates. In some species, however, all roots senesce in autumn.

The Pleistocene climate-controlled fluvial sedimentary record in the Bełchatów mine (central Poland)

Sedimentological analyses of fluvial formations in the Bełchatów mine have yielded results that have more than regional significance. They concern the reaction of rivers to climatic changes in the Pleistocene. Changes in river geometry and their depositional records are examined from two fluvial formations. These formations represent different times, but show similar palaeoenvironmental changes. Cool temperate climate conditions resulted in meandering (or anastomosing) river sedimentation, which was controlled by equalized precipitation and by a well-developed vegetation cover. Cold periglacial climate conditions resulted in braided river sedimentation immediately before the Glacial Maximum, with high discharges and a high sediment load. The palaeoclimatic and palaeohydrologic analyses of the Weichselian fluvial deposits in Bełchatów provide additional information to that from similar studies in Germany and the Netherlands, thus jointly resulting in a consistent palaeogeographic model of western-middle Europe.

Molecular phylogeny of the Drosophila virilis section (Diptera: Drosophilidae) based on mitochondrial and nuclear sequences

Regardless of the well-documented virilis species group, most groups of the Drosophila virilis section have not been completely studied at molecular level since it was suggested. Therefore, phylogenetic relationships among and within species groups of the virilis section are generally unknown. In present paper, the complete mitochondrial ND2 gene and fragment of COI gene in combination with a nuclear gene, Adh coding region, were used to derive the most extensive molecular phylogeny to date for the Drosophila virilis section. A total of 111 individuals covering 61 species were sampled in this study. Novel phylogenetic findings included (1) support for the paraphyly of the melanica and robusta species group and at least two subgroups of the robusta species group, the lacertosa and okadai subgroups, were distinguished as paraphyletic taxa. In addition, (2) present results revealed the sister relationship between D. moriwakii and the robusta subgroup, conflicting with current taxonomy regarding D. moriwakii, which was shifted from the robusta species group to the melanica group. (3) In contrast to the robusta and melanica species groups, monophyly of the polychaeta species group, the angor group and the virilis group was confirmed, respectively. However, the monophyletic quadrisetata species group was resolved with uncertainty. (4) Our analyses of combined data set suggested close relationship between the quadrisetata species group and the unpublished clefta group, and the okadai subgroup is sister to the clade comprising of the quadrisetata and clefta species groups. Within the virilis section, D. fluvialis and three tropical species groups, the polychaeta group, the angor group and the repleta group, are found to branch off earlier than other ingroup taxa. This suggests that the virilis section might have originated in the Old World tropics. Besides, the derived status of the close affinities of the quadrisetata group, the clefta group, and the melanica and robusta groups is probably the result of their adaptation to forests between subtropical and cool-temperate climate. Based on the consideration of the phylogenetic placement of the species of the virilis section, we suggest that at least five independent migrations occurred from the Old World to the New World.

DICKINSARTELLA FAUNA FROM THE SAIWAN FORMATION (OMAN): A BIVALVE FAUNA TESTIFYING TO THE LATE SAKMARIAN (EARLY PERMIAN) CLIMATIC AMELIORATION ALONG THE NORTH-EASTERN GONDWANAN FRINGE.

The transitional faunas of the Permian Huqf succession of Oman make it one of the key-sections for the intercalibration of Early to Middle Permian biostratigraphical scales. The abundance of fossils improved the knowledge of some marine faunas which populated the North-Eastern Gondwanan fringe during times of climatic changes in the Permian. A Sterlitamakian (upper Sakmarian, Lower Permian) bivalve from the Saiwan Formation in the Huqf area, informally named Dickinsartella Fauna, is described in the present paper. The specimens examined were collected from the Pachycyrtella (Auctorum), the basal of the Formation in its type locality. The Dickinsartella Fauna can be identified for the presence of the new genus Dickinsartella , which dominates the bivalve thanatocoenosis with D. pistacina sp. n. (type species). The bivalve from the Pachycyrtella Bed includes the new species Stutchburia sangallii and Promytilus mazzolenii, and also Astartella obliqua Dickins, 1963, Nuculopsis cf. bangarraensis Dickins, 1963, ? Oriocrassatella sp., and indeterminable aviculopectinids. This shows a low taxonomic diversity. Nevertheless, some species are represented by a high number of generally well-preserved specimens, i.e. some specimens of S. sangallii sp. n. and A. obliqua show part of the ligament. The good preservation of the shells permitted the microstructural analysis of D. pistacina sp. n. and S. sangallii sp. n. The microstructure of S. sangallii sp. n. supports the close phylogenetical link between modiomorphids and crassatelloids recognized by some previous authors. The new genus Dickinsartella includes the more recent species belonging to the important Paleozoic Order Cyrtodontida Scarlato & Starobogatov, 1971. The discovery of Dickinsartella gen. n. and other taxa of the Pachycyrtella Bed, present also in the Sakmarian levels of the Carnarvon and Perth Basins in Western Australia, indicates a wider distribution of the Dickinsartella Fauna and confirms the correlation between Arabian and Australian series already remarked by previous authors. The Dickinsartella fauna is the first bivalve testifying to the climatic amelioration gradually affecting the North-Eastern Gondwanan fringe at the end of the Early Permian glacial events. This pioneer spread out, probably in a cool-temperate climate, on the substrate provided by the mid-Sakmarian (basal Sterlitamakian) transgression, connected with the final stages of the Gondwanan deglaciation and/or with initial sea-floor spreading in the Neotethys. In the present paper some remarks on the autecology of the new species from the Pachycyrtella bed are also discussed.

冷温帯林土壌圏の炭素動態 : 3. 特定土層に基づく土壌炭素貯留量の簡便調査・推定法

冷温帯林土壌圏の炭素動態 : 3. 特定土層に基づく土壌炭素貯留量の簡便調査・推定法

Some ecophysiological and historical approaches to species richness and calcicole/calcifuge behaviour — contribution to a debate

Species richness in vascular plants was related to the plants’ calcifuge or calcicole behaviour using documentation from forests and open-land vegetation at about one thousand sites in the southern parts of Sweden. It is concluded that vegetation of strongly acid soils (pH-KCl < 4.5) have fewer vascular plant species than comparable vegetation of other soils, whereas there are no consistent differences in species richness between slightly-moderately acid and calcareous sites. Low species richness is particularly related to high concentrations of Al3+ and H+ ions (either soil solution concentrations or concentrations of exchangeable ions), not to a lack of calcium carbonate. The majority of plant species are able to render the sparingly soluble phosphate, iron and manganese compounds of high-pH soils available, but they are unable to tolerate much Al3+ or H+. Acidicole (calcifuge) species have developed the power of tolerating Al3+ and H+, which may be considered a secondary property of plants, but they have lost the power of solubilizing critical mineral nutrients in high-pH soils. The reasons why these ecophysiological properties are inversely related in the current flora are obscure, difficult to account for experimentally and a main ecological problem. In areas with cool-temperate climates the flora was partly or mainly extinguished by the Pleistocene glaciations. Comparatively fewer calcifuge than calcicole species have, since then, had enough time to develop, and the number of calcifuges is lower, in spite of the fact that most natural and seminatural soils of these areas are nowadays acidic.

Clay-mineralogical characteristics of soils distributed under warm-temperate forest climate in Nyu Mountains, Fukui Prefecture, Central Japan

The vertical distribution of the clay minerals in the profiles of the five soils occurring in the Nyu mountains, namely Dark red soils, Kunimidake series, KNM soil; Dry brown forest soils, Takasu-1 series, TKS soil; Dry brown forest soils (reddish), Tega series, OSI soil; Red soil, Oshibayama series, DAI soil; and Yellow soils, Yada series, MAT soil, compared with Hyperdistri-Rhodic Cambisol, Hyperdistri-Chromic Cambisol, and Hypereutri-Chromic Cambisol of WRB was analyzed quantitatively from the viewpoint of pedogenesis. The results are summarized as follows: Smectite originating in pyroxine andesite which had undergone hydrothermal degradation was altered to chlorite-smectite intergrade in the AB and Bwl horizons, and to chlorite in the A and AB horizons of the KNM soil, suggesting that this soil had been formerly affected by the past warm climate. This intergrade mineral, however, reversely changed to smectite in the surface horizon due to the influence of eluviation of the interlayered hydroxy aluminum of the intergrade mineral under the present cool-temperate climate. The TKS, OSI, and MAT soils, Yellow-Brown Forest soils, were characterized by the presence of chlorite-vermiculite intergrade and chloritization in the surface horizon in terms of clay mineralogy. Based on the clay-mineral composition, the zonal soil under the Warm-temperate deciduous broad-leaved forest climate in the surveyed area was a Yellow-Brown Forest soil. The DAI soil, as paleo-red soil, was formed by the weathering of autochthonous rocks, but the subsurface horizon of the OSI soil, as a paleosol, originated in the loess brought from the Asian continent, based on the clay-mineral composition.

Effect of elevated soil temperature on radiation-use efficiency in peanut stands

In cool-temperate climate regions, low (below optimum) soil temperature is critical for radiation-use efficiency (RUE) of the peanut stands. Despite its negative effect, few studies have quantified the relationship. To study the effect of soil temperature on RUE of peanut stands, we conducted field experiments for 2 years with three soil temperature treatments—ambient, reduced, and elevated. Season-long, from sowing until harvest, mean temperatures of the three treatments were about 23.5, 21.7 and 25.7 °C, respectively. The stands grown under the elevated soil temperature converted significantly more of the absorbed photosynthetically active radiation (PAR) into dry matter. Such higher RUE was accounted mainly for the higher carbon exchange rate (CER) due to the synthesis of more chlorophyll pigments (Chl a+ b) at early growth stages. Across treatments and years, RUE varied from 1.07 to 1.53 g MJ −1. Irrespective of treatments and years, the RUE and soil temperature were positively correlated ( r 2=0.99; P<0.001). The regression equation was: RUE=−1.16+0.11 T. Elevated soil temperature would enhance to accumulate relatively higher stand biomass per unit use of radiation that substantiates such linearity. It is concluded that elevating the soil temperature is a useful method of compensating for low air temperatures, allowing more efficient capture of resources especially in cool-temperate regions.

Annual pasture legumes for farming systems in cool-temperate areas with summer soil moisture deficits

Seed softening rates of subterranean clover (Trifolium subterraneum) are lower in cool-temperate environments than in typical Mediterranean areas, allowing the accumulation of large seed banks. These large seed banks should enable a pasture to selfregenerate following a year of cropping in which the pasture has been removed. To test this hypothesis, a 1:1 pasture/crop rotation system was established at three sites in southern Victoria, Australia, with subterranean, balansa (T. michelianum), Persian (T. resupinatum) and arrowleaf (T. vesiculosum) clovers. At Hamilton, pure subterranean clover herbage yields of up to 10 t DM/ha were obtained under grazing. This was followed by wheat grain yields averaging 7 t/ha with 12.7% grain protein over three seasons. After a year of dryland cropping, the pastures selfregenerated with more than 3 000 clover seedlings/ m2. At Gnarwarre and Streatham, all four clover species were well adapted to the pasture/crop rotation in terms of their seed-seedling dynamics, with the highest regeneration after cropping at 8 000 seedlings/m2 in balansa clover and the highest seasonal herbage production of 12.8 t DM/ha in arrowleaf clover. No nitrogen fertiliser was applied in the system. Key words: annual legumes, cool-temperate climate, crops, seed softening rates

Depositional environment of Bagra Formation (Upper Triassic), Satpura Basin, India: a palynological approach

Bagra Formation is the youngest lithounit of non-marine Mahadeva Group in Satpura Basin. The recorded palynological assemblage from Bagra Formation contains prominence of fungal and algal remains. Palynomorphs of Denwa Formation such as Falcisporites, Satsangisaccite, Samaropollenites, Arcuatipollenites, Strialopodocarpites including Callialasporites, Cycadopites, Corollina (=Classopollis) simplex and Haradisporites are also represented in the Bagra Assemblage. The palynological assemblage (as a mixed flora) suggests a lateral continuity of the Denwa Formation with younger Bagra Formation, and the difference could be facies variations. The recovered palynological assemblage suggests a Rhaetian age of Upper Triassic to the Bagra Formation. The palynological associations indicate that Bagra Formation was deposited in lacustrine set up near shoreline under cool-temperate climate with derivation of palynomorphs from heavy rain forest upland areas.