Cold Temperate Regions Research Articles

Deep eutectic solvent strategy for green extraction of chlorogenic acid from sea buckthorn: optimization and sustainability

BackgroundSea buckthorn (Hippophae rhamnoides), a deciduous species plant, is widely distributed around the globe, and native to the cold-temperate regions of Europe and Asia. This medicinal herb contains several bioactive constituents including chlorogenic acid. The conventional methods used for the extraction of phenolic antioxidants from natural herbs often result in low yields, high toxicity, and pose environmental hazards limiting their effectiveness and scalability. Therefore, green extraction techniques using deep eutectic solvents, composed of natural, non-toxic, and biodegradable components were applied for extraction of chlorogenic acid from sea buckthorn weed. Fourteen deep eutectic solvent mixtures were prepared and evaluated for extraction yield of chlorogenic acid. Parameters such as hydrogen bond donor-to-hydrogen bond acceptor ratio, liquid-to-solid ratio, shaking speed, and shaking time were optimized for the best mixture.ResultsThe combination of lactic acid and maltose (1:1) was found to give best extraction yield using response surface methodology. The deep eutectic solvent system under optimum conditions produced 12.2 g/100 g of crude extract sea buckthorn containing 174.7 mg gallic acid equivalents (mg GA)/g) of extract. Moreover, the optimized extract exhibited appreciable radical scavenging capacity (91%), trolox equivalent antioxidant capacity (11.2% of extract), and inhibition of peroxide in linoleic acid (80.6%). High-performance liquid chromatography-based characterization revealed the extracts contained chlorogenic acid (20.1 mg/g of extract) as the major constituent.ConclusionsIn summary, the adoption of DES for the extraction of bioactive phenolic constituents from sea buckthorn offers multiple benefits, including economic efficiency, enhanced extraction performance, and environmental sustainability. The findings of this study not only advance the understanding of DES in phytochemical extraction but also pave the way for broader application of green solvents in the natural products industry. Future research should focus on further optimizing DES formulations and scaling up the extraction process to fully realize the potential of this innovative extraction method in commercial applications.

Relative Importance of Macroalgae and Phytoplankton to Nearshore Consumers and Growth Across Climatic Conditions in the Northern Gulf of Alaska

Macroalgae and phytoplankton support the base of highly productive nearshore ecosystems in cold-temperate regions. To better understand their relative importance to nearshore food webs, this study considered four regions in the northern Gulf of Alaska where three indicator consumers were collected, filter-feeding mussels (Mytilus trossulus), pelagic-feeding Black Rockfish (Sebastes melanops), and benthic-feeding Kelp Greenling (Hexagrammos decagrammus). The study objectives were to (1) estimate the proportional contributions of macroalgal and phytoplankton organic matter using carbon and nitrogen stable isotopes, (2) determine if macroalgal use affected consumer growth using annual growth rings in shells or otoliths, and (3) describe changes in organic matter use and growth during the Pacific Marine Heatwave (PMH; 2014–2016) in one consumer, mussels. Macroalgae were the major organic matter source (> 60%) to the diet for all three consumers. The relationships between macroalgal contribution and growth were neutral for both fish species and significantly positive for mussels. During the PMH, mussels had a drop (> 10%) in macroalgal contributions and grew 45% less than in other time periods. Simultaneously, the relationship between macroalgal contribution and mussel growth was strongest during the PMH, explaining 48% variation compared to 3–12% before or after the PMH. Collectively, the results suggest that macroalgae is likely more important to cold-temperate nearshore food webs than phytoplankton. Management actions aimed at conserving and expanding macroalgae are likely to benefit nearshore food webs under all climate scenarios and especially during marine heatwaves.

The Relationship between Endogenous Hormone Content and Related Gene Expression and Tillering in Wild Kentucky Bluegrass

Poa pratensis is widely distributed in cold temperate regions and can be used as a species for stress restoration and as a forage for livestock. Studying the genetic characteristics of tillering occurrence in bluegrass provides a theoretical basis for studying plant yield formation, environmental adaptation, and improving survival competitiveness. The regulating effects of endogenous hormone IAA content and the expression of related genes ARF1, ARF12, ARF14, ZT content and the expression of related genes CKX2, CKX3, CKX4, SL content and the expression of related genes D14-like, D14.1-like and D14 in wild Kentucky bluegrass were investigated. Kentucky bluegrass from Sunan and Qingshui was used to evaluate the influence of hormone and gene expression on tillering behavior. Endogenous hormone contents and expression levels of related genes in stems and roots of both materials were measured at prophase, peak, and anaphase of tillering. The results showed that among the three materials, the Sunan material had a better tillering ability for Poa pratensis, while the Qingshui material had poorer tillering ability. The downregulation of CKX2, CKX3, and CKX4 gene expression levels promotes the synthesis of ZT, thereby improving the tillering ability of the germplasm. Upregulation of ARF14, D14, and D14.1-like gene expression levels enhances the synthesis of IAA and SL, thereby inhibiting tillering. More importantly, the interaction between hormones affects the tillering ability of bluegrass, and high levels of ZT/IAA, ZT/SL, and ZT/(IAA+SL) values promote tillering. In summary, this study reveals the mechanism by which hormones regulate the occurrence of tillering in Kentucky bluegrass, providing a theoretical basis for understanding the genetic characteristics of plant type, effectively regulating tillering, studying yield development, environmental adaptation, and improving survival rate.

Beyond Phosphorus: Salinization as a driver of eutrophication symptoms in North American lakes

The acceleration of global urbanization continues to fuel concerns surrounding water quality impairments in urban lakes, particularly eutrophication. Eutrophication of freshwater environments is generally assumed to be driven by increased anthropogenic phosphorus (P) supplies which can alleviate limitations on primary production. Salinization is also recognized as a stressor on urban freshwater quality, particularly in cold temperate climate regions where salts are applied to road surfaces as de-icing agents. While the ecological damages caused by P enrichment and salinization to freshwaters are both well established, thus far, their impacts on water quality have only been considered independently. Although improvements to the management of urban stormwater and wastewater have decreased P inputs to freshwater systems in recent decades, many lakes worldwide remain eutrophic, as indicated by declining dissolved oxygen (DO) concentrations and rising dissolved inorganic P (DIP) concentrations in the hypolimnion. Our previous study of an urban freshwater lake in Ontario, Canada, showed that persistent eutrophication symptoms are linked to salinization associated with impervious land cover expansion, rather than increased external P loading. In this research, we present a multiple decade of water chemistry data analyses for several other urban lakes in Ontario, Wisconsin, and Minnesota to determine how increased lake salinization rates intersect with water temperature and morphometry to alter water column stratification, thus, increasing eutrophication symptoms. Our trend analysis shows progressive salinization (observed through significant increases in chloride or electrical conductivity) of all the lakes investigated. Calculations of lakes mixing indices over time show that, on average, lake stratification is becoming more stable with increased salinity playing a crucial role in enhancing lake stratification. Overall, salinity is becoming a stronger regulator of water density than temperature in the cold temperate urban freshwater lakes of North America. The increasing salinity trends are accompanied by increasing hypolimnion hypoxia and increasing DIP to total P (TP) ratios in all lakes, thereby demonstrating the mechanistic link between salinization and internal P loading. Rising salinity intensifies water column stratification, in turn, reducing the oxygenation of the hypolimnion and enhancing internal P loading from the sediments. These results highlight that stricter management of de-icing salt application rates should be considered to control lake eutrophication symptoms in cold climate regions.

Improving Phenology Representation of Deciduous Forests in the Community Land Model: Evaluation and Modification Using Long‐Term Observations in China

AbstractPhenology is an important factor indicating environmental changes and regulates the variations of carbon, water, and energy exchange. However, phenology models exhibit large uncertainties due to limited understanding of its mechanisms. In this study, we modified deciduous phenology scheme based on the evaluation of different phenological models using long‐term observations at Chinese Ecosystem Research Network with CLM4.5. The alternating leaf unfolding model and summer‐influenced autumn leaf falling model that we proposed, performed best in simulating leaf‐unfolding and leaf‐falling. Compared with the observed and remote‐sensed phenology, the modified model could better simulate the phenological dates at the site and regional scale. Moreover, the modified model improved the simulation of gross primary productivity (GPP) by decreasing the errors of modeled carbon uptake duration and amplitude. Furthermore, the advance in leaf‐unfolding slowed down from 0.20 days/year during 1981–2015 to 0.11 days/year during 2016–2100 under RCP4.5 because of the slowdown of climate warming, but the delay in leaf‐falling changed little. By the last decade of the twenty‐first century, the leaf‐unfolding would advance (8 days) and leaf‐falling would delay (16 days). The subtropical region had large interannual variation (IAV) in leaf‐unfolding because of the high sensitivity to temperature. The phenological dates IAV in the cold temperate region increased due to enhanced temperature IAV. We suggest that the deciduous phenology models, especially the leaf‐falling process, used in Community Land Model need to be improved to reduce the errors in predicting phenology and carbon flux in the future.

Spatiotemporal distribution patterns of soil nematodes along an altitudinal gradient in the cold temperate zone of China

As important components of the cosmopolitan soil biota, soil nematodes are found at multiple trophic levels of the belowground food web and play an important role in soil function. Exploring the actual patterns of soil nematodes along the altitudinal gradients helps understand the spatial soil ecology. In this study, we used molecular analysis approaches to reveal the soil nematode spatiotemporal changes on Oakley Mountain in the northern Greater Khingan Mountain Ranges Northeast China. Our results showed that although the alpha diversity of nematode communities generally decreased with the increased altitude, it did not exhibit a monotonic decrease pattern. Bacterial feeding nematodes occupied the largest proportion among all nematode feeding types. Altitude had a more significant effect than soil depth on the structure of nematode community in all seasons. Soil bulk density, moisture, dissolved organic carbon, temperature, pH, nitrate nitrogen, and total phosphorus were the significant soil variables driving the composition of nematode community. The co-occurrence networks of soil nematode communities showed a distinct seasonal pattern. The nematode community networks in May and September had more modes and links, higher average degrees, and higher average clustering coefficients than the network in July. We demonstrated that the variance of nematode community structure in different altitudes and soil depths could be well explained by edaphic factors. This study extends our knowledge of the nematode spatial ecology in cold temperate regions and contributes to further investigation of soil ecological processes in global challenges.

Are yellow dung flies domesticated cow dung specialists?

The theory of niche differentiation implies some extent of specialization of species with regard to key resources, notably food. Coprophagous (dung-eating) insect larvae play a critical role in the decomposition of livestock dung in modern and traditional agricultural grasslands. The yellow dung fly (Scathophaga stercoraria L.; Diptera: Scathophagidae) is one of the largest, most common and abundant dung decomposers on pastures in cold-temperate regions across the entire northern hemisphere. As this fly is often associated with domesticated cattle or dairy cows, which are commonly kept for human nutrition worldwide (beef, milk, cheese, etc.), it is sometimes suspected to be a cow dung specialist. However, yellow dung flies are regularly active on and around other dung types, and must have reproduced on dung of wild vertebrates before the domestication of cattle. We therefore experimentally studied the performance of yellow dung fly larvae on dung of various large domestic vs. wild mammals (cow, horse, wild boar, red deer) in the laboratory in Switzerland. Larval performance in terms of juvenile survival, egg-to-adult development time, growth rate, and final adult body size, the major life history indicators of individual reproductive success, did not vary greatly among the various dung types tested. Thus, yellow dung flies can successfully reproduce on multiple types of mammal (vertebrate) dung, wild and domestic, and are therefore dung generalists rather than specialists. We conclude that yellow dung flies are common in European low- and highlands because they could plastically shift to dung of common herbivorous livestock after their domestication without losing the ability to reproduce on dung of common wild mammals.

The role of temperature in shaping Culex acharistus mosquitoes life history traits in its southern limit of distribution (Patagonia-Argentina)

There is substantial evidence showing that temperature have a great impact on insects behavior, phenology and life histories. Because of mosquito global importance as disease vectors, in temperate regions where climatic conditions could be only borderline suitable for mosquito development, there is a growing interest in understanding the effect of temperature shifts on vital statistics to more accurately define how such changes could impact distribution and abundance patterns, as well as disease transmission cycles. We determined the role of ambient temperature under fluctuating conditions in shaping Culex acharistus (Diptera: Culicidae) life history traits, and estimated its development threshold and physiological time, in its southern limit of distribution in the Argentine Patagonia region. Four horizontal life tables were conducted under natural fluctuating temperature range in Esquel city (42°S – 71°W; 563 m a.s.l.), during spring-summer (17°C), summer (15.4°C), summer-autumn (12.7°C) and autumn-winter (5.6°C) seasons. Larvae, pupae and adult traits were recorded. The mean duration of the experiments varied between 28 to ≅100 days for spring-summer and autumn-winter seasons. Only during the cold season experiment pupae experienced the most severe temperatures and freeze-thaw cycles, and failed to reach adult stage. We found that larva and pupa development time, adult emergence time and longevity significantly increased with decreasing temperatures, while larval survival was greatest at an intermediate temperature and decreased toward low and high values. Also, protandry was observed and males emerge 2 days before females across seasons. Temperature development threshold and physiological time estimated for larva + pupa were 5.98°C and 211.24°C-days. Our study contributes to a growing body of knowledge by examining the effect of seasonal changes in temperature on mosquito life history traits. Results obtained here can be applied as useful parameters in the development of population dynamic models, improving current mosquito control strategies in cold-temperate regions.

Grain yield, yield components and nitrogen economy of irrigated second-crop common Buckwheat (Fagopyrum esculentum Moench) in a cold-temperate region

Common buckwheat (Fagopyrum esculentum Moench) is a species with great nutritional value and promising to be cultivated as a second crop in irrigated fields of cold-temperate regions with short growing seasons. However, little information exists regarding the nitrogen (N) economy of common buckwheat as a second crop following a high-yielding winter cereal. This study aimed to quantify grain yield, its components, and the grain protein content, and to evaluate N economy processes such as the initial N use efficiency (INUE), the N uptake efficiency (NUptE), the N internal efficiency (NIE) for biomass and grain yield and the N harvest index (NHI) among different treatments of N availability at sowing in four site-year experiments of common buckwheat as a second crop in irrigated fields of the southwestern Pampas of Argentina. The variety Mancan, used in this study, lasted between 73 and 92 days (888–1073 °C days) from sowing to harvest. Grain yield was highly correlated with achene number but not with achene weight. Grain yield ranged from 405 to 2725 kg ha-1, with an interaction between treatments and experiments, with major differences among experiments and minor differences among N availability treatments. Relative N uptake was maximized at a higher value of N availability (160 kg N ha-1) than grain yield (50 kg N ha-1), associated with higher responses of N uptake, vegetative N uptake and grain protein content than grain yield to N availability. However, NUptE featured a negative response to N availability in all experiments. NHI was highly variable among experiments, ranged between 0.51 and 0.83 and was affected by N availability in only two experiments. NIE for biomass and grain yield were 80 kg kg-1 and 36 kg kg-1, respectively, which were lower than those of most cereals but higher than those of other non-cereal grain crops. A short crop cycle of the variety Mancan, an average grain yield of 1594 kg ha-1 among experiments in this study, a low N availability requirement to maximize grain yield and high values of NIE for biomass and for grain yield suggest that buckwheat is a promising species for second crop sowing in cold-temperate regions.

Feasibility study of cultivating desi‐type chickpea genotypes in cold and temperate regions

AbstractShifting the sowing time of chickpea plants from spring to autumn in arid and semi‐arid regions of Iran is unavoidable. To study the feasibility of this issue, 32 desi‐type chickpea genotypes were planted in Mashhad (as a temperate region) and Jolgeh Rokh (as a cold region) to screen cold‐tolerant genotypes. The results revealed that 100% and 19% of the genotypes planted in Mashhad and Jolgeh Rokh had a survival range of 76–100%. MCC918 in Mashhad and MCC913 in Jolgeh Rokh had the highest height (69 and 33 cm, respectively). The highest biological yields in Mashhad and Jolgeh Rokh were found in MCC576 (1743 g m−2) and MCC207 (658 g m−2), respectively. The grain yield of 41% (13 genotypes) and 34% (11 genotypes) of the genotypes planted in Mashhad and Jolgeh Rokh was higher than the total average (316 and 82 g m−2, respectively). Also, the maximum grain yield in Mashhad was about 2.3 times higher than in Jolgeh Rokh. According to the present experimental results, MCC259, MCC576, and MCC607 in Mashhad as a cold temperate region and MCC207, MCC212, and MCC605 in Jolgeh Rokh as a cold region had the highest winter survival percentage and grain yield compared to the other genotypes.

The global dynamic of DNA methylation in response to heat stress revealed epigenetic mechanism of heat acclimation in Saccharina japonica.

Saccharina japonica is an ecologically and economically important kelp in cold-temperate regions. When it is cultivated on a large scale in the temperate and even subtropical zones, heat stress is a frequent abiotic stress. This study is the first attempt to reveal the regulatory mechanism of the response to heat stress from the perspective of DNA methylation in S. japonica. We firstly obtained the characteristics of variation in the methylome under heat stress, and observed that heat stress caused a slight increase in the overall methylation level and methylation rate, especially in the non-coding regions of the genome. Secondly, we noted that methylation was probably one of factors affecting the expression of genes, and that methylation within the gene body was positively correlated with the gene expression (rho=0.0784). Moreover, it was found that among the differentially expressed genes regulated by methylation, many genes were related to heat stress response, such as HSP gene family, genes of antioxidant enzymes, genes related to proteasome-ubiquitination pathway, and plant cell signaling pathways. This study demonstrated that DNA methylation is involved in regulating the response to heat stress, laying a foundation for studying the acclimation and adaptation of S. japonica to heat stress from an epigenetic perspective.

First assessment of seagrass carbon accumulation rates in Sweden: A field study from a fjord system at the Skagerrak coast

Seagrass meadows are globally important blue carbon sinks. In northern cold-temperate regions, eelgrass (Zostera marina) is the dominant seagrass species, and although their sedimentary carbon stocks have been quantified across regions, information regarding the CO2withdrawal capacity as carbon sinks remains scarce. Here we assessed the carbon (Corg) accumulation rates (CARs) and stocks as well as the organic matter sources in five seagrass meadows in the Gullmar Fjord area on the Swedish Skagerrak coast. We found that the mean (±SD) CAR was 14 ± 3 g Corgm-2yr-1over the last ~120–140 years (corresponding to a yearly uptake of 52.4 ± 12.6 g CO2 m-2). The carbon sink capacity is in line with otherZ.marinaareas but relatively low compared to other seagrass species and regions globally. About half of the sedimentary carbon accumulation (7.1 ± 3.3 g Corgm-2yr-1) originated from macroalgae biomass, which highlights the importance of non-seagrass derived material for the carbon sink function of seagrass meadows in the area. The Corgstocks were similar among sites when comparing at a standardized depth of 50 cm (4.6–5.9 kg Corgm-2), but showed large variation when assessed for the total extent of the cores (ranging from 0.7 to 20.6 kg Corgm-2for sediment depths of 11 to at least 149 cm). The low sediment accretion rates (1.18–1.86 mm yr-1) and the relatively thick sediment deposits (with a maximum of >150 cm of sediment depth) suggests that the carbon stocks have likely been accumulated for an extended period of time, and that the documented loss of seagrass meadows in the Swedish Skagerrak region and associated erosion of the sediment could potentially have offset centuries of carbon sequestration.

Comparing Realized and Potential Distributions of the Species of Taurocerastinae (Coleoptera: Geotrupidae) to Examine the Relevance of Dispersal Limitations and Contemporary Environmental Factors

By compiling all available occurrence information for the three species of Taurocerastinae (Frickius costulatus Germain, 1897, Frickius variolosus Germain, 1897, and Taurocerastes patagonicus Philippi, 1866), their realized and their world potential distributions were predicted to estimate the role played by dispersal limitations and contemporary environmental factors in explaining their extant distributions. Variables related to productivity seemed to have a higher explanatory capacity for the distribution and spatial segregation of each species. The realized and potential distribution estimates suggest that these species occupy all South American territory with environmentally suitable conditions and that the contemporary distribution of taurocerastine species can be basically conditioned by their geographical isolation within the cold and cold-temperate regions of South America. However, environmental factors would be comparatively more relevant in the case of the apterous species, T. patagonicus, due to the small potential world area with environmentally favorable conditions.

Phenotypic plasticity in the monoclonal marbled crayfish is associated with very low genetic diversity but pronounced epigenetic diversity.

Clonal organisms are particularly useful to investigate the contribution of epigenetics to phenotypic plasticity, because confounding effects of genetic variation are negligible. In the last decade, the apomictic parthenogenetic marbled crayfish, Procambarus virginalis, has been developed as a model to investigate the relationships between phenotypic plasticity and genetic and epigenetic diversity in detail. This crayfish originated about 30 years ago by autotriploidy from a single slough crayfish Procambarus fallax. As the result of human releases and active spreading, marbled crayfish has established numerous populations in very diverse habitats in 22 countries from the tropics to cold temperate regions. Studies in the laboratory and field revealed considerable plasticity in coloration, spination, morphometric parameters, growth, food preference, population structure, trophic position, and niche width. Illumina and PacBio whole-genome sequencing of marbled crayfish from representatives of 19 populations in Europe and Madagascar demonstrated extremely low genetic diversity within and among populations, indicating that the observed phenotypic diversity and ability to live in strikingly different environments are not due to adaptation by selection on genetic variation. In contrast, considerable differences were found between populations in the DNA methylation patterns of hundreds of genes, suggesting that the environmentally induced phenotypic plasticity is mediated by epigenetic mechanisms and corresponding changes in gene expression. Specific DNA methylation fingerprints persisted in local populations over successive years indicating the existence of epigenetic ecotypes, but there is presently no information as to whether these epigenetic signatures are transgenerationally inherited or established anew in each generation and whether the recorded phenotypic plasticity is adaptive or nonadaptive.

Co-elevation of atmospheric [CO2] and temperature alters photosynthetic capacity and instantaneous water use efficiency in rice cultivars in a cold-temperate region.

Crop photosynthetic capacity in response to climate change likely constrains crop productivity and adaptability to changing environments, which requests the investigation on the dynamics of photosynthetic parameters over growth season among varieties, especially in cold-temperate regions. Three Japonica rice cultivars i.e., Shoubaimao (SH), Hejiang 19 (HJ); Longjing 31, (LJ). were planted under the control, e[CO2] (700 μmol mol-1), warming (2°C above the air temperature) and the co-elevation of [CO2] and temperature in open-top chambers (OTC). The objective of this study is to examine the rice photosynthetic parameters, water use efficiency (WUE) and yield formation in responses to the co-elevation of [CO2] and temperature which is the main predicted features of future climate. e[CO2] significantly increased An of SH, HJ and LJ by 37%, 39% and 23% in comparison to 34%, 34% and 27% under elevated [CO2] plus warming, respectively. However, An had a weak response to warming for three cultivars. [CO2] and temperature co-elevation significantly decreased the stomatal conductance, resulting in a significant increase of the WUE. e[CO2] significantly increased Vc, max , Jmax and Jmax /Vc, max . e[CO2] significantly increased grain yield and grain number of all cultivars. The positive effect of co-elevation of [CO2] and temperature on grain yield was less than e[CO2]. Warming is likely to partially offset the increased photosynthetic rate caused by e[CO2]. The [CO2] and temperature co-elevation may be favorable to rice crop with increasing the photosynthetic ability of rice crop and improving water use efficiency. The present study provided evidence that the rice genotypic difference in photosynthetic potential under [CO2] and temperature co-elevation. Therefore, it is crucial to explore a broader range of phenotypes and cultivars to be applied to climate change response research, advancing the knowledge that climate change impacts rice crop under the cold-temperate climate region.

Biogeography of algae and invertebrates from wave-exposed rocky intertidal habitats along the Atlantic coast of Nova Scotia (Canada): Latitudinal and interannual patterns and possible underlying drivers

Biogeographic studies aim to understand species distributions and are becoming increasingly relevant to establish baselines to monitor ecological change. The NW Atlantic coast hosts a cold-temperate biota, although knowledge about its biogeography is patchy. This study documents for the first time biogeographic variation at mid-to-high intertidal elevations in wave-exposed rocky intertidal habitats along the open Atlantic coast of Nova Scotia (Canada), a hydrographically distinct subregion of this cold-temperate region. For this goal, we measured the summer abundance of algae and invertebrates at the same nine locations over four consecutive years (2014 to 2017) spanning 415 km of coastline, which allowed us to examine latitudinal and interannual patterns. In addition, we looked for mensurative evidence on possible drivers underlying these patterns, focusing on sea surface temperature, daily maximum and minimum temperature (which often happen at low tides at thus differ from sea surface temperature), pelagic food supply for intertidal filter-feeders (phytoplankton abundance and particulate organic carbon), drift sea ice during the cold season (which can cause intertidal disturbance), and species associations. Our field surveys revealed that northern locations can be severely disturbed by ice scour when drift ice is abundant and, while biological recolonization occurs over the years, it differs in pace among locations. Southern locations, instead, did not experience ice scour during our study and, thus, generally exhibited a higher species richness and abundance than northern locations. Multivariate analyses indicated that the aforementioned expressions of temperature and pelagic food supply explained together 32–55% of the variation in alongshore biogeographic pattern, depending on the year. Species association analyses suggest that algal foundation species (generally more abundant at southern locations) contribute to increase location-wise species richness. Mensurative evidence for bottom-up forcing in seaweed–herbivore and filter-feeder–predator systems differed greatly among years. Overall, in addition to its inherent value to advance NW Atlantic intertidal biogeography, our species distribution database should be valuable to assess ecological change decades into the future as climate change and other anthropogenic influences unfold.

Control of snow mold damage of winter wheat by snow compaction (Yuki-fumi)

Snow mold, a disease of grasses and winter cereals under snow in cold temperate regions incited by cold-adapted fungi, is characterized by the ability to grow at sub-zero temperatures but differ in eco-physiological features. We hypothesized that snow compaction (yuki-fumi) might affect the thermal conditions under snow coverage, ultimately alleviating snow mold severity. Yuki-fumi was conducted using machinery attached to a tractor in winter wheat fields for five years; yuki-fumi in midwinter or both in early winter and midwinter reduced the damage due to Typhula ishikariensis and Microdochium nivale in snowy winters. The damage by Sclerotinia borealis was minimized in the winter when snow cover occurred late in the season. Yuki-fumi reduced the number of days with continuous soil temperatures at 0 ± 0.5 °C to less than 30 days and mitigated snow mold damage, consequently improving wheat growth regardless of snow mold species. These results indicate that conditions critical for snow mold development may be manipulated through yuki-fumi, making it a cost-effective and environmentally friendly control measure against snow mold.

Study of Apple Varieties in High-Density Plantation under Cold Dry Temperate Conditions of Kinnaur

The study was carried out to evaluate four apple varieties on different rootstocks under high-density plantations in the cold temperate region of Kinnaur for growth, yield and quality attributes. The experiment evaluated four apple varieties ‘Red Cap Valtod/MM 106’, ‘Red Velox/M9’, ‘Jeromine/M9’ and ‘Super Chief/MM 106’ planted at a spacing of 2.5×1.0 m2 in Randomized Block Design, with four replicates. From the evaluation of data on growth, floriculture and quality standards, it was clear that var. Jeromine/M9 followed by Red Velox/M9 has recorded better horticultural performance than other varieties studied. Among different varieties Red Velox/M9 recorded maximum shoot extension growth (22.65 cm), trunk girth (47.27 mm) and tree height (340.02 cm), tree spread (175.52 E-W and 181.68 cm N-S), number of fruit set tree-1 (41.85), fruit Breadth (78.90 mm), fruit weight (207.39 g fruit-1), TSS (10.11 °Brix), whereas, maximum fruit set (25.48%), fruit length (71.74 mm), yield (3.59 kg tree-1) and productivity (14.35 MT Hac-1) was recorded in cultivar Jeromine/M9. However, the maximum number of fruits tree-1 was observed in the variety Red Cap Vatod/MM 106. Variety, Red Velox /M9 was found to be superior for growth, flowering, yield and quality characteristics with good market potential under Kinnaur conditions.

First Report of Sea Buckthorn Stem Wilt Caused by Fusarium proliferatum in Liaoning, China.

Sea buckthorn（Hippophae rhamnoides L.） is a flowering shrub native to cold-temperate regions of Eurasia, which is also valuable for its berries and leaves containing various vitamins and flavonoids (Pundir et al. 2021). In late June 2020, high mortality (more than 70%) was observed in sea buckthorn in a 1.6-ha seedling nursery in Chaoyang City, Liaoning province, China, where 16 Chinese and Russian cultivars (cv.) had been planted since 2014 (cv. Shenqiuhong, eshi01 through eshi15). The mortality of two introduced sea buckthorn varieties (eshi02, eshi04) was 100% (125 trees died in total). The symptoms include massive drooping leaves and dried-up stems on 6-year-old infected trees. Pieces of tree roots and stems with brown discoloration in the xylem vessels were selected. Small tissue fragments (0.2-0.5 cm) were surface disinfested (3 min in 75% ethanol, rinsed with sterile distilled water), air-dried, and placed on potato dextrose agar (PDA) medium for 5 days at 25°C in the dark. A fungus was consistently isolated from both diseased roots and stems tissues, and a representative isolate (LC-1) was harvested. Genomic DNA was extracted for amplification and sequencing of the partial translation elongation factor-1α (EF1 and EF2 primers, accession Nos. MZ669853) (O'Donnell et al. 1998) and RNA polymerase II second largest subunit (RPB2) (7cf/11aR primers, accession Nos. MZ669854) (O'Donnell et al. 2007). The sequences were further analyzed at the Fusarium MLST (https://fusarium.mycobank.org/) for identity confirmation, and showed 99.8% (over 95.2% query coverage) and 96.4% (over 88.4% query coverage) similarity to Fusarium proliferatum (NRRL 13584, 13591). Isolates on Spezieller Nahrstoffarmer agar (SNA) produced abundant aerial white mycelia and yellow pigmentation. The 30 macroconidia measured ranged from 28.5 - 62.5 × 3.2 - 5.4 μm, were thin, slender, with 3-5 septa. The aseptate microconidia ranged from 4.7 - 13.6 × 2.2 - 4.3 μm (n = 30). Pathogenicity tests were performed on healthy, potted 1-year-old sea buckthorn seedlings (cv. eshi05) using two isolates in a greenhouse at 25 °C, 80% relative humidity, and 12-hour light/dark photoperiod. Ten potted seedlings were inoculated on the stems by placing a 5-mm-diameter mycelial plug (5-day-old PDA cultures for each isolate) into the surface of a wound created with a needle, and the inoculation sites were covered with Parafilm to maintain moisture. Ten seedlings were inoculated with PDA plugs as controls. Six to ten days after inoculation, color of the leaves in the middle of the stems was variegated, and then dark necrotic lesions on leaf margins were observed. Three weeks after inoculation, 80% of inoculated stems were wilted, while control plants remained asymptomatic. The pathogen was consistently re-isolated and the recovered isolates were identified as F. proliferatum by amplifying the EF-1α gene. The typical symptoms on inoculated plants were dark to brown necrotic lesions on chlorotic leaves initially, and black withered stems in the terminal stage, similar to those observed on sea buckthorn trees infected with Fusarium sporotrichioides in Gansu and Heilongjiang provinces (Song et al. 2010; Xia et al. 2021). To our knowledge, this is the first report of sea buckthorn stem wilt caused by F. proliferatum in Liaoning province, China, which will be beneficial for expanding knowledge of Fusarium disease in sea buckthorn and provide more information for sustainable disease management in sea buckthorn.

Genetic variation of the endangered species Halenia coreana (Gentianaceae)

Halenia coreana is an endangered, endemic species that is distributed in only a few locations in Korea, such as Mts. Hwaaksan and Daeamsan. It has been recently segregated from H. corniculata, broadly distributed in cold temperate regions that include northern Japan, the Russian Far East, northeastern China, Mongolia, and eastern Europe, where population sizes are usually large. To examine the genetic diversity of H. coreana and evaluate the level of genetic differentiation of the species compared with that of H. corniculata, we surveyed 183 candidate simple sequence repeats (SSR) motif markers for H. coreana and H. corniculata from sequence data of amplified fragments of a specific length in the genome. A total of 17 genomic-SSR markers were selected to examine the levels of genetic diversity and differentiation using 17 samples of H. coreana and 60 samples of three populations of H. corniculata. The results here suggest that the genetic diversity of H. coreana is very low with a high frequency of inbreeding within its population. We found that H. coreana is genetically differentiated from H. corniculata, supporting the recognition of the geographically isolated H. coreana as a distinct species.