Northern Limit Of Distribution Research Articles

Phytogeographic Considerations on the Flora of Mt. Abu

The Aravallis intersect the State of Rajasthan in a southwest-northeast direction. Mt. Abu on the Aravallis is the highest point in the wide gap between the Himalayas and the Nilgiris, and thus has phytogeographlc significance. The flora of Mt. Abu has been compared with that of other hilly regions of India, and also with the flora of adjacent regions of the dry zones. It is observed that : i. the flora of Mt. Abu has some representation of mountain element belonging to subtropical and temperate regions of India. This element comprises three groups of plants, namely, (a) those occurring in all or most hilly regions of India, such as in Himalayas, Parasnath, Pachmarhi, Western Ghats, Nilgiris, etc. (26 species); (b) plants found in the Himalayas or moist places of northern India, whose southern limit is the Mt. Abu (19 species); and (c) plants found in the Ghats and hills of Deccan Peninsula and whose northern limit of distribution is Mt. Abu 38 species).ii. there are only a few plants of alpine regions in this flora;iii. large number of plants are of wide general distribution;iv. biotic factors are resulting in increase of xerophytic species on this hill.A study ofthe world distribution of the plants of Mt. Abu shows that:i. out of 469 species, 267 are tropical;ii. 80 species are eastern, southeastern, Asian and Australian;iii, 46 species are African-Arabian; andiv. 22 species are American. The American plants are mostly weeds of cultivation.

Phenology and the response of photosynthesis to irradiance and temperature gradient in the herbal drug red alga, Chondria armata (Rhodomelaceae, Ceramiales) from Kagoshima, Japan

AbstractSeasonal changes in the size of the herbal drug red alga Chondria armata (Rhodomelaceae, Ceramiales) were investigated in Kagoshima, Japan, which is near the northern distributional limit in the western Pacific. Additionally, its photosynthetic response to irradiance and temperature was examined using dissolved oxygen sensors and a pulse amplitude modulation (PAM)-chlorophyll fluorometer. This alga was observed in tidepools throughout the year; its height and weight were greatest in December and the lowest in April and May. The net photosynthesis of the photosynthesis–irradiance (P–E) curve determined at 28°C quickly saturated at 113 µmol photons m-2 s-1, with minimal inhibition even at 1000 µmol photons m-2 s-1. The gross photosynthesis of the photosynthesis–temperature (P–T) curved over 8 to 40°C, measured at 500 µmol photons m-2 s-1, peaked at 30.1°C and decreased rapidly below 20°C and above 36°C, respectively. Similarly, the effective quantum yield (ΔF/Fm') after a 3-day culture during 4–40°C at 50 µmol photons m-2 s-1 remained stable between 16°C and 32°C but decreased outside of this range. The combined effect of irradiance (200 [low] and 1000 [high] µmol photons m-2 s-1) and temperature (28, 22, and 16°C) revealed that ΔF/Fm' declined during exposure to high irradiance at all temperature treatments. However, it mostly recovered after a subsequent 12-hour period of dim-light acclimation at 28°C and 22°C. In contrast, those at 16°C could not recover, indicating the occurrence of low-temperature light stress. This alga appears to be well-adapted to the irradiance and temperature environment at the study site. However, the winter temperature appears to approach its threshold level, and the occurrence of strong light during the winter might adversely affect the abundance of this alga near its northern distributional limit.

Lower thermal tolerance restricts vertical distributions for juvenile albacore tuna (Thunnus alalunga) in the northern limit of their habitats

IntroductionEvaluating the thermal tolerance of commercially valuable tuna species and their behavioral responses to the limits of this tolerance is essential for evaluating the effects of changes in water temperature driven by global climate change on their distribution and fisheries. We aimed to identify the lower thermal tolerance (Tmin) of juvenile albacore tuna (ALB) and evaluate their behavioral response to Tmin by focusing on wild behavior in the northern distributional limit. Additionally, we investigated how vertical behavior is linked to the vulnerability of ALB to Japanese longline (LL) and pole-and-line (PL) fisheries.MethodsWe explored the swimming depths and water temperatures of four previously reported tagged individuals migrating from subtropical to temperate areas and identified Tmin and its depths in the water column as unfavorable depths (DTmin). To investigate the spatial patterns of ALB fishery grounds for LL and PL fisheries, we analyzed hotspots specific to each type of gear using the historical Japanese fishery logbook for both fisheries.ResultsComparisons of the fishery grounds between the two fisheries revealed that PL hotspots appeared in the northern areas, while LL hotspots were in the southern regions. We also discovered that the vertical distribution of ALB became shallow in high-latitude areas, which were strongly affected by DTmin shallowing at high latitudes.DiscussionThese results provide evidence of a behavioral response among juvenile ALB that avoids Tmin by remaining at the surface. We discuss the implications of the results for latitudinal changes in the vulnerability of ALB to fisheries in terms of the overlapping depth between ALB vertical habitats and the gear-setting depth for each fishery.

History of Diversification and Adaptation from North to South Revealed by Genomic Data: Guanacos from the Desert to Sub-Antarctica.

The increased availability of quality genomic data has greatly improved the scope and resolution of our understanding of the recent evolutionary history of wild species adapted to extreme environments and their susceptibility to anthropogenic impacts. The guanaco (Lama guanicoe), the largest wild ungulate in South America, is a good example. The guanaco is well adapted to a wide range of habitats, including the Sechura Desert, the high Andes Mountains to the north, and the extreme temperatures and conditions of Navarino Island to the south. Guanacos also have a long history of overexploitation by humans. To assess the evolutionary impact of these challenging habitats on the genomic diversity, we analyzed 38 genomes (∼10 to 16×) throughout their extensive latitudinal distribution from the Sechura and Atacama Desert to southward into Tierra del Fuego Island. These included analyses of patterns of unique differentiation in the north and geographic region further south with admixture among L. g. cacsilensis and L. g. guanicoe. Our findings provide new insights on the divergence of the subspecies ∼800,000 yr BP and document two divergent demographic trajectories and to the initial expansion of guanaco into the more southern portions of the Atacama Desert. Patagonian guanacos have experienced contemporary reductions in effective population sizes, likely the consequence of anthropogenic impacts. The lowest levels of genetic diversity corresponded to their northern and western limits of distribution and some varying degrees of genetic differentiation. Adaptive genomic diversity was strongly linked with environmental variables and was linked with colonization toward the south followed by adaptation.

Dynamics of vegetation of Central Yamal in the holocene

The paper presents new paleobotanical data in combination with the results of radiocarbon dating obtained from organomineral deposits of the northern shore of Lake. Pechevalavato (70°13’22.3” N, 71°50’57.6” E) in the Seyakha river basin and characterizing the dynamics of vegetation in the northern part of Central Yamal in the Holocene. It has been established that in the Early Holocene (10.2–8.7 thousand years ago) in Yamal, tree-shaped birch (Betula sect. Betula) grew no less than 400 km north of the modern northern limit of distribution of Betula pubescens ssp. tortuosa. Favorable conditions for the existence of birch woodlands at this time were due to the higher temperature of the growing season, exceeding by approximately 3–4 °C the modern parameters of the warmest month of the summer season. At the end of the Early Holocene (after 8.5 thousand cal BP), forest vegetation began to degrade, and open landscapes with diverse plant communities of the subarctic tundra and single trees in the river valley spread. About 6.5 thousand cal BP the northern subarctic tundra began to form the zonal appearance of the study area in climatic conditions close to modern ones.

Parasitic findings on threatened pudu deer from Central Chile accounts first genetic characterization of lice parasitizing P. puda in Chile and the first molecular report of Taenia hydatigena metacestodes in this species

Southern pudu (Pudu puda) is a threatened endemic deer of the temperate forests of Chile. In recent years pudu populations rates have decreased mainly due to anthropogenic causes including forest loss and landscape fragmentation. In this context, the parasitic fauna of Chilean pudu has been scarcely investigated. The aim of this study was to determine the parasitic status of rescued pudu n = 13 from its natural habitat in Central Chile (Maule region) during March 2022 and June 2023 by applying morphological, histopathological, and molecular analyses. As result, we report the presence of transmission of parasites from dogs to pudus as showed by the presence of metacestodes of the parasite Taenia hydatigena on omentum, liver, and pleura of pudus during postmortem examinations, being the first molecular report on the presence of this parasite on Chilean pudu. Meanwhile, ectoparasite examinations determined the presence of chewing and sucking lice on pudu exemplars here analysed. Molecular and phylogenetic analysis of lice revealed new insights on Bovicola and Anoplura lice parasitizing P. puda in Chile, equally being the first genetic characterization of lice parasitizing pudu exemplars in Chile. In addition, parasite loads of lice and metacestodes were analysed. However, no statistically significance was observed when comparing environmental and individual traits influence on parasite load variation. Overall, the study area is the northern limit of habitat distribution of this specie in Chile and we here provide novel information on pudu deer parasites, thus making a useful and valuable contribution to the parasitological knowledge on this threatened species.

ОСОБЕННОСТИ ЭКОЛОГО-ГЕОГРАФИЧЕСКОЙ ПРИУРОЧЕННОСТИ РЕДКОГО ВИДА TULIPA BORSZCZOWII REGEL (LILIACEAE) В ПРЕДЕЛАХ КАЗАХСТАНА

The article presents the results of critical review of available herbarium specimens of Tulipa borszc-zowii Regel (Liliaceae) – a rare species listed in the List of Rare and Threatened Plant Species (2006); Red Books: Kazakh SSR (1981), South Kazakhstan (Turkestan) region (2002); Republic of Kazakhstan (2014), Kyzylorda region (2014). The aim of the study was to investigate its current distribution and ecological habitat to identify potential growing sites within the Republic. Specimens of the studied species stored in such major Herbaria as: AA, TASH, MW, LE were reviewed. A total of 147 herbarium specimens were viewed during the study. Also, in the process of work was carried out screening of domestic and foreign sources (including electronic databases) containing information on the places of Tulipa borszczowiigrowth. As a result of the research: the morphological description of the species was supplemented with detailing the range of color gamma of perianth lobes; the northern boundaries of the Kazakh part of the Tulipa borszczowii area were specified, which are simultaneously the northern limits of distribution of the species as a whole and the list of floristic areas of Kazakhstan in which it is fixed was expanded; a map-scheme of the species locations within the Republic was drawn up; The tasks for further research are formulated, in particular, the need for biometric studies and clarification of both the northwestern and northeastern limits of Tulipa borszczowii growth.

Sexual reproduction of <i>Acropora pruinosa</i> at its northern distributional limit

Sexual reproduction of <i>Acropora pruinosa</i> at its northern distributional limit

Dimorphopterus blissoides (Hemiptera: Heteroptera: Blissidae): recent spreading of a neonative species in the Pannonian Basin.

Dimorphopterus blissoides (Baerensprung, 1859) (Hemiptera: Heteroptera: Blissidae) is recorded for the first time from Slovakia and Iran. We provide also additional records of D. blissoides from Bulgaria, Croatia, Greece, Hungary and Romania, and review the distribution of the species. The species is currently spreading in the Pannonian Basin, reaching its northern distribution limit in southern Slovakia. We confirm its development on Phragmites australis, with preference to the loose outer leaf sheaths of the galls of Lipara lucens Meigen, 1830 (Diptera: Chloropidae), where the specimens develop during summer as well as hibernate during winter.

Differences in the reproductive output and larval survival of Rocky Mountain wood ticks (Dermacentor andersoni) and American dog ticks (Dermacentor variabilis) from prairie populations near their northern distributional limits in western Canada.

The effects of temperature and relative humidity (RH) on female reproductive output, egg development and larval survival were determined for Rocky Mountain wood ticks (Dermacentor andersoni) from a prairie population (Chin Lakes, Alberta, Canada) near the northern distribution limit of this species. The responses of D. andersoni eggs and unfed larvae to different temperature (25 or 32°C) and RH (35, 55, 75, 85 or 95%) regimes were compared to our previously published data (Diyes et al. 2021) for a northern prairie population of American dog ticks (Dermacentor variabilis). Oviposition by D. andersoni females took 21-30 days at 25°C and 95% RH compared to 10-21 days for D. variabilis. The number of eggs laid by female ticks was strongly dependent on their engorgement weight, and D. andersoni females produced more eggs than D. variabilis females of an equivalent body weight. Eggs of D. andersoni took less time to develop at 32°C than 25°C with ≥ 85% RH, and hatched faster than those of D. variabilis. Larval survival times declined as temperature increased and RH decreased, but D. andersoni survived longer at 32°C and ≤ 75% RH than D. variabilis. The interspecific differences in responses to the same temperature and humidity regimes indicate that D. andersoni is xerophilic, whereas D. variabilis is hydrophilic. Hence, 'prairie' populations of the Rocky Mountain wood tick occur in the drier grassland ecoregions but are absent in Aspen Parklands Ecoregion which is located to the north and east of the distributional range of D. andersoni.

Effect of snow cover on the off-host survival of Dermacentor variabilis (Acari: Ixodidae) larvae.

The geographical range of the American dog tick, Dermacentor variabilis (Say), in Canada continues to expand northwards into areas with colder winter temperatures. Understanding what influences the off-host survival of D. variabilis over winter is important for predicting the northern distributional limit of this species. A field experiment was conducted to determine the effect of snow cover on the off-host survival of unfed D. variabilis larvae from a population situated near the northern distributional limit in Saskatchewan, Canada. Ticks were placed in tubes within 1 of 9 field enclosures (tickaria) in early fall. The 9 tickaria were divided into 3 equal treatment groups: no snow cover, natural snow cover (maximum depth of 25 cm) and extra snow cover (maximum depth of 32 cm). Tick survival was measured in mid-winter and in early spring (i.e., ~17 and ~26 wk after start of experiment). The results showed that snow cover had a significant impact on the relative humidity, but not temperature, in the tickaria. Larvae in tickaria with no snow cover had a higher mortality rate (27%) than larvae in tickaria with natural snow cover (6%) or extra snow cover (4%). Although snow cover enhanced off-host survival, many individuals were able to survive in sub-zero temperatures under leaf litter in the absence of continuous snow cover for a period of 108 days. These findings have implications for the construction of predictive models to determine the northern distributional limits of D. variabilis, a species that is an important vector of several pathogens.

Interpopulation Variability of Polyphenol Concentration in the Leaves of <i>Spiraea aquilegifolia</i> (Rosaceae) from the Republic of Buryatia

Abstract—Composition and content of flavonoids and phenol carboxylic acids in the leaves of Spiraea aquilegifolia Pall. from natural populations of the Republic of Buryatia (Western Transbaikalia) are given in the article. Aqueous ethanol (40%) extracts from raw materials were used for chromatographic study of phenolic compounds. The analysis of phenolic compounds was carried out on an analytical High-Performance Liquid Chromatography (HPLC) system consisting of an Agilent 1200 liquid chromatograph (USA) with a diode array detector, an autosampler, and a system for collecting and processing chromatographic data ChemStation. At least 24 phenolic compounds were identified in aqueous ethanol extracts from Spiraea aquilegifolia Pall. leaves by HPLC. Three acids (chlorogenic, p-coumaric and p-hydroxybenzoic) and six flavonols (hyperoside, isoquercitrin, avicularin, astragalin, quercitrin and kaempferol) were identified among them. Flavonols hyperoside (2.9–8.2 mg/g), avicularin (3.0–5.8 mg/g) and isoquercitrin (0.8–2.5 mg/g) are the main substances in aqueous ethanol extracts from leaves. Plants from populations located at the northern distribution limit in the Western Transbaikalia have a higher content of phenol carboxylic acids (near the village Koma) and flavonols (near the village Klyuchi). Plants from populations located to the eastern limit (near villages Kusoty and Zagan) have the lowest concentration of identified phenolic compounds. A high and very high level of interpopulation variability of the studied biochemical parameters has been established. This can be explained by the functional significance of the identified compounds and their active participation in general metabolic processes in the plant. The content of identified free phenolic acids and flavonols in S. aquilegifolia was characterized by medium and high levels, compared to other studied Spiraea species. This confirms the prospects for further study of the composition of phenolic compounds of S. aquilegifolia.

Off-host survival of Dermacentor variabilis (Acari: Ixodidae) adults near their northern distributional limit in Saskatchewan, Canada.

Dermacentor variabilis (Say) is expanding its range northwards in Saskatchewan and Manitoba (Canada). Knowledge of the relative ability of different life cycle stages to survive off-host over winter is important for assessing the potential for further range expansion and risk of pathogen transmission. In the present study, the off-host survival of D. variabilis adults was determined in outdoor terraria within a field plot close to Lizard Lake Community Pasture (LLCP) situated near the northern distributional limit in Saskatchewan. Only a small proportion (7%) of adult ticks in this relatively recently established population survived from mid-summer to late winter. Off-host survival had declined further to <4% by mid-spring. A significantly greater proportion of female ticks (6%) survived from mid-summer to mid-spring than did male ticks (1%). The supercooling points (SCPs), the temperature below 0 °C when body fluids spontaneously freeze, of the 17 ticks that survived through to mid-spring did not differ significantly from the SCPs of questing ticks in the previous summer, suggesting adult D. variabilis do not undergo cold hardening during winter diapause. The off-host survival of D. variabilis adults near LLCP was also much lower than that previously reported for adults from Sandy Hook in Manitoba, a population that has been established for decades. This finding suggests that there is geographical variation in the ability of D. variabilis in southern Canada to survive from mid-summer to the subsequent spring. However, the ecological and genetic factors influencing the survival of northern populations of D. variabilis requires further investigation.

Is the protection of habitat directive Eleocharis carniolica in its northern limits really needed? – A life strategy based investigation

Eleocharis carniolica is included in the EU Habitat Directive and legally protected in many European countries. It is also considered as one of the most threatened plants in Poland. It typically occurs in muddy habitats, wet meadows, lake or pond shores or temporary puddles, but in Poland this species usually occurs at disturbed anthropogenic sites such as road verges or drainage ditches. Despite being the focus of a number of ecological and conservation studies, E. carniolica still does not have a fully recognized ecology and life-strategy, particularly with regard to breaking seed dormancy and germination. To find out the population performance and species propagation potential in Poland, we have conducted experiments aimed at assessing the seed germination conditions and efficiency. The main goal was to discover the crucial factors that stimulate germination. The results of the experiments suggest that light is a pivotal factor for triggering germination of E. carniolica seeds. Moreover, E. carniolica’s seed bank consisted of about 80 % dormant seeds. The only effective method for dormancy breaking was warm stratification (placing the seeds at high temperature on a moist substrate) with application of gibberellic acid (GA3), and even a few days of warm stratification resulted in effectively overcoming dormancy. Eleocharis carniolica's germination features are typical for plants adapted to frequent disturbances with a short life expectancy and large reproductive effort. Our results strongly suggest that E. carniolica has a ruderal life strategy at its northern distribution limits and probably can be considered as an alien species in Poland.

Similar growth responses to climatic variations in Norway spruce (Picea abies) and European beech (Fagus sylvatica) at the northern range limit of beech

In south-east Norway, in the hemiboreal vegetation zone, beech reaches its northern distribution limit and typically occupies the same type of sites as spruce. Under future climate change, this area is projected to fall within the temperate zone and beech to increase its distribution towards the north at the expense of spruce. However, such forecasts are based on very broad scale estimates and the knowledge of climatic adaptation and the competitive potential of the beech and spruce populations at these latitudes is scarce. Here, we use a dendrochronological approach to study the growth performance of neighbouring spruce and beech trees to climate variability over a period of 70 years. The two species responded quite similarly to variations in climate in the study area. Both showed increased incremental growth in response to high precipitation both in the previous and present year June, indicating that water is a limiting resource. In addition, beech showed a negative response to high temperatures in previous July and August, which is probably connected with growth reductions due to masting. Overall, spruce and beech in the hemiboreal zone show comparable responses to climatic variations as in the temperate zone. Due to the different drought-handling strategies of the two species, we suggest that the intensity of summer droughts and the variability between years are likely factors that would be decisive for which of them that will be more successful under future climatic conditions.

Inshore migration of Japanese eel Anguilla japonica encouraged by active horizontal swimming during the glass eel stage

AbstractThe biomass of the Japanese eel (Anguilla japonica) is generally determined by the recruitment of glass eels into freshwater habitats, but the behavioral biology of their inshore migration remains unknown. With the aid of an ocean prediction system, we elucidated a recruitment migration scenario that can quantitatively reproduce a regional difference in biomass in Japan, which was previously estimated by an environmental DNA sampling method. For their successfully reaching shores, it is necessary to incorporate behavioral changes of glass eels within their migration on the Kuroshio Current, such as shallower depth preferences and horizontal swimming toward lower salinity water. In particular, the latter is essential for encouraging recruitment into both the Seto Inland Sea, with a relatively high ratio (20%–30%) of the total recruitment to Japan and the coasts in the central part of the Pacific side of northern Japan (i.e., the northern limit of the habitable distribution), manifesting that glass eels actively swim toward freshwater near coastal regions. In the subsurface layer, where glass eels mainly conduct diel vertical migration, there is a bifurcation path connecting the Kuroshio Current to the second and third branches of the Tsushima Warm Current, restricting the recruitment of glass eels into the Sea of Japan side of the main inland in Japan. The simulated recruitment validated that the eDNA acts as a proxy indicator for estimating the relative biomass on the regional scale. The simulation supported that the inshore migration of glass eels is determined by active horizontal swimming.

Population demography of rare sedges (Eriophorum gracile and Carex livida) north of the Arctic Circle in Murmansk Region and climate change impacts

Species of Cyperaceae are little studied on the population level globally. Also in Murmansk Region, species from this family were not included in long-term population studies of rare plant species whereas other representatives from 21 families were put in [Blinova, 2009]. Experimental works with sedges is often neglected because of taxonomic difficulties and a lack of methods for study populations of this group [Kitamura et al., 2016; Sosnovska, Danylyk, 2017]. Such difficulties became obvious while the IUCN-red data book testing. Of rare sedges studied in this paper Eriophorum gracile is included in the regional Red data book [Kozhin, 2014] and Carex livida is in the Appendix of this book in the group Need of monitoring. &#x0D; &#x0D; The Murmansk Region (6670 N), located in the north-eastern corner of Russian Fennoscandia, is a part of the Atlantic-Arctic zone of temperate belt with a rather mild climate. The region is very heterogeneous. Two latitudinal vegetation zones can be distinguished: tundra and taiga. So, many boreal plant species reach here their northern limit of distribution. Our field work has been conducted in the center part of the region in a recently found rich fen [Blinova, Petrovskij, 2014]. Both study species (Eriophorum gracile и Carex livida) have circumpolar distribution in wetlands of northern hemisphere [Hulten, Fries, 1986], and they are at the northern range in Murmansk Region [Kuzeneva, 1954; Chernov, 1954]. They are polycarpic perennials. An annual shoot has been selected as a counting unit (Fig. 1). In E. gracile only the number of generative shoots has been counted in the field. For non-destructive purposes, from herbarium data, the ratio between generative and vegetative shoots was defined as 1:1. The total population size for this species has been estimated from this ratio. In population of C. livida, the direct counting in the field has been done on 3-5 small plots (0.25*0.25 м2). Lately this value has been recalculated according to the area of population subset. Clusters and subsets have been distinguished in population structure according to suggested aggregation patterns of spatial structure in local plant populations [Blinova, 2018]. Marked population subsets have been monitored several times in the growing period in 2014-2016 years. In the field the boundaries and areas of rich fen and populations (including subsets) have been estimated with the help of GPS navigation device Garmin Dakota 20, in the lab all data are further processed using Garmin Software BaseCamp 4.2.5. Nomenclature for vascular plants is given according to S. K. Czerepanov [1995], for mosses after M. S. Ignatov O. M. Afonina [1992]. &#x0D; &#x0D; Our results show that extremely low (0.2% for Eriophorum gracile) and relatively low (3.1% для Carex livida) population cover is characteristic for a large long-term monitored fen. Spatial aggregation of E. gracile population is structured on very small area (40 м2) whereas C. livida is established on relatively representative area (633 м2). E. gracile develops small population subsets (8 m2 on average) at a distance to next about 70 m in different parts of rich fen. Each such subset contains 9-10 mature individuals on average. C. livida has larger subsets (211 m2 on average) at 30 m away from the neighbor. The size of each subset makes c. 2500 generative shoots. The spatial population pattern of E. gracile shows isolated subsets with single clusters, whereas of C. livida represents isolated subsets with merged clusters. High fluctuations of population size and its subsets are revealed in E. gracile from year to year. The number of generative shoots and air temperature in the growing season (June-September) of the current year establish negative relationship.&#x0D; &#x0D; This study in one of the northernmost populations of Eriophorum gracile confirms other data from different parts of its distribution area that populations of this species are very fragmented and show high fluctuations in the number of generative shoots [Barr 1996; Ksermann, Moser, 1999; Dickenmann, Keel, 2004; Decker et al., 2006; Chatters, Sanderson, 2014]. An analysis of spatial structure of populations has been pointed out that anemochory of E. gracile could be a bottleneck for the population fitness in rich fens conditions, whereas baro- and hydrochory of C. livida promotes further seed germination and survival. Additionally, current climate-changed impacts could cause an extirpation of E. gracile from floristic composition of rich fens, whereas such a threat is minimal for C. livida. Both species need regional protection of their populations. An introduction into culture is essential for further ontogenetic studies and trigger examination of clonal division of labor.

Energy metabolism of juvenile scallops Nodipecten subnodosus under acute increased temperature and low oxygen availability

High temperature increases energy demand in ectotherms, limiting their physiological capability to cope with hypoxic events. The present study aimed to assess the metabolic tolerance of juvenile Nodipecten subnodosus scallops to acute hyperthermia combined with moderate hypoxia. A previous study showed that juveniles exhibited a high upper temperature limit (32 °C), but the responses of juveniles to combined hyperthermia and low dissolved oxygen are unknown. Scallops were exposed to control conditions (treatment C: 22 °C, ∼7.1 mg O2 L−1 or PO2 156.9 mmHg), acute hyperthermia under normoxia (treatment T: 30 °C, ∼6.0 mg O2 L−1 or PO2 150.9 mmHg) or acute hyperthermia plus hypoxia (treatment TH: 30 °C, ∼2.5 mg O2 L−1 or PO2 62.5 mmHg) for 18 h. In T, juveniles exhibited an enhanced oxygen consumption, together with a decrease in adenylate energy charge (AEC) and arginine phosphate (ArgP), and with no changes in metabolic enzyme activity in the muscle. In TH, scallops maintained similar AEC and ArgP levels in muscle as those observed in T treatment. This response occurred along with the accumulation of inosine monophosphate and hypoxanthine. Besides, reduced citrate synthase and pyruvate kinase activities, enhanced hexokinase activity, and a higher octopine dehydrogenase/lactate dehydrogenase ratio in the mantle indicated the onset of anaerobiosis in TH. These responses indicate that juvenile scallops showed tissue-specific compensatory responses regarding their energy balance under moderate hypoxia at high temperatures. Our results give an insight into the tolerance limit of this species to combined hyperthermia and hypoxia in its northern limit of distribution.

Progress on Geographical Distribution, Driving Factors and Ecological Functions of Nepalese Alder

As the oldest species of Betulaceae, Nepalese alder (Alnus nepalensis) shows a high capacity for nitrogen fixation, rapid growth rate, and strong adaptability to stress environments, and it plays an important role in maintaining the structure and function of forest and agroforestry ecosystems. We explored its geographic distribution and the corresponding environmental drivers through collecting specimen records and published literature for Nepalese alder over the world during the past 40 years. The research trends, the growth limiting factors, the physiological characteristics, and ecological functions were all summarized as well. In terms of geographical distribution and limiting factors, Nepalese alder is mainly distributed in southern mountainous areas of the Himalayas and southwest China. Since it presented a clear northern limit of distribution and an upper limit of elevation, temperature is assumed to be the main environmental limiting factor. According to historical development, the research history of Nepalese alder could be divided into three main periods: the initial development (before 2001), the fast development (2002–2015), and the high-quality development (2016–2022), with the two key points in 2002 and 2015 relating to the conversion of cropland to a forest project that the government conducted and the application from theory to practice, respectively. As can be seen from the ecological functions, Nepalese alder could form symbiotic nodules with Frankia, which plays an important role in improving soil physical and chemical properties and facilitating vegetation secondary succession. Overall, the present review provides a reference for further studies on ecological adaptability and sustainable utilization of Nepalese alder under climate change, and also for regional ecosystem service, forestry production practice, and vegetation restoration.

Northward range expansion ofLeptogorgia dakarensisandEunicella racemosa(Cnidaria: Gorgoniidae: Anthozoa) in the Eastern Atlantic

AbstractIdentifying species and updating marine biodiversity is fundamental to understanding the evolution of ecosystems and adopting appropriate management strategies. These ecosystems are threatened by climate change causing species mobility, mortality, etc. An important zoological group in the marine ecosystem, octocoral gorgonians have a wide geographic and bathymetric distribution. However, the knowledge of their presence on the Atlantic West African coasts remains limited. Herein, we note the accurate geographic distribution of two species,Leptogorgia dakarensis(Stiasny, 1936) andEunicella racemosa(Milne Edwards &amp; Haime, 1857), reporting their northern distributional limits. The gaps in the previous knowledge hypothesis of the oceanic warming effects explaining the northward mobility of these species are discussed here.