Prostrate Shrub Research Articles

Climate Predicts NDVI Better Than Plant Functional Group Attributes Along a Latitudinal Gradient in Nunavik

ABSTRACTAimThis study aims to describe the latitudinal pattern in plant functional groups' (PFGs') biomass and cover in Nunavik to test whether PFG attributes are better Normalized Difference Vegetation Index (NDVI) predictors than climate.LocationThe study spans a 700‐km latitudinal gradient from the lichen woodland to prostrate shrub tundra vegetation zones across Nunavik, Canada.TaxonOur analysis focuses on the following PFGs: erect and prostrate shrubs, herbaceous plants, bryophytes, and lichens.MethodsBiomass and cover data of the different PFGs were sampled in 40 sites distributed across the latitudinal gradient. NDVI data were obtained through remote sensing, while climatic, permafrost depth, and surficial deposits were derived from various databases. The PFG models were built to explore relationships between average NDVI (2016–2020) at the sampling site and ecological attributes such as PFG biomass or cover but also other variables such as surficial deposits and permafrost depth. A second series of models, the climatic models, were built using only climatic variables such as seasonal temperature and precipitation.ResultsThe most parsimonious PFG model was built with the biomass data of erect shrubs, herbaceous plants, bryophytes, and lichens and included surficial deposits and permafrost depth (R2 = 0.74). This biomass model performed better than the most parsimonious cover model (cover of erect shrubs and herbaceous, surficial deposits, permafrost depth; R2 = 0.63). However, the most parsimonious climatic model (fall temperature, annual, and winter precipitations) exhibited superior predictive power compared to the ecological ones (R2 = 0.87).ConclusionsPFG models built with PFGs aboveground biomass or cover are good predictors of NDVI of the plant formations sampled along the latitudinal gradient in Nunavik. Despite the intrinsic association between NDVI and vegetation attributes, our study emphasizes the importance of the regional climate in the control of primary productivity in Arctic and subarctic ecosystems. This study provides new insights into the interpretation of NDVI data and enhances our understanding of Arctic vegetation responses under rapid climate change. Furthermore, it underscores the balance between climatic drivers and ecological dynamics in shaping fragile Arctic ecosystems.

Age matters: Older Alnus viridis ssp. fruticosa are more sensitive to summer temperatures in the Alaskan Arctic

Abstract The Arctic is rapidly warming, and tundra vegetation community composition is changing from small, prostrate shrubs to taller, erect shrubs in some locations. Across much of the Arctic, the sensitivity of shrub secondary growth, as measured by growth ring width, to climate has changed with increased warming, but it is not fully understood how shrub age contributes to shifts in climate sensitivity. We studied Siberian alder, Alnus viridis ssp. fruticosa, a large nitrogen‐fixing shrub that has responded to climate warming with northward range expansion over the last 50 years. We used serial sectioning of 26 individual shrubs and 94 cross‐sections to generate a 98‐year growth ring chronology, including one 142‐year‐old, Siberian alder in Northern Alaska. We tested how secondary growth sensitivity to climate has changed over the past century (1920–2017) and how shrub age affects climate sensitivity of alder growth through time. We found that over time, alder growth as expressed by the stand chronology became more sensitive to July mean monthly air temperature. Older shrubs displayed higher sensitivity to June and July temperature than younger alders. However, during the first 30 years of growth of any shrub, temperature sensitivity did not differ among individuals. In addition, the June temperature sensitivity of growth series from individual cross‐sections depended on the age of the attached shrub. Our results suggest that age contributes to climate sensitivity, likely through modifying internal shrub carbon budgets by changing size and reducing alder's dependence on N‐fixation over time. Older, more sensitive alder may enhance C and N‐cycling while having greater recruitment potential. Linking alder age to climate sensitivity, recruitment and total N‐inputs will enable us to better predict ecosystem carbon and nitrogen cycling in a warmer Arctic. Read the free Plain Language Summary for this article on the Journal blog.

Recent waning snowpack in the Alps is unprecedented in the last six centuries

Snow cover in high-latitude and high-altitude regions has strong effects on the Earth’s climate, environmental processes and socio-economic activities. Over the last 50 years, the Alps experienced a 5.6% reduction per decade in snow cover duration, which already affects a region where economy and culture revolve, to a large extent, around winter. Here we present evidence from 572 ring-width series extracted from a prostrate shrub (Juniperus communis L.) growing at high elevation in the Val Ventina, Italy. These ring-width records show that the duration of current snowpack cover is 36 days shorter than the long-term mean, a decline that is unprecedented over the last six centuries. These findings highlight the urgent need to develop adaptation strategies for some of the most sensitive environmental and socio-economic sectors in this region.

Quantitative Ethnobotanical Report of Wild Flowers used by Tribes of Wayanad Forest Division, Kerala- India

The quantitative ethnobotany deals the computation and importance of the plants and vegetation to people. It helps quantification of qualitative data in the biological and social science. The traditional source of medicinal plants is an important way for daily curative uses in the rural area. A survey was carried out among the tribes of Munnar forest division, Idukki district, Kerala India. The present study identified traditionally using 47 species of ethnomedicinal plants distributed in 41 genera belonging to 29 families to treat various diseases. Moreover, among the plant studied habit wise analyzed they are 12 herbs, 13 shrubs, 12 trees, each one of climbing shrub, twining shrub, prostrate shrub, climber. The status of plants are analyzed and recorded as 26 common, 14 rare, 5 common & Cultivated and 2 sporadic are described under this study. In this communication, the information’s got from the rural inhabitant were compared with the already existing literature. The data were col- lected randomly from tribal and healers of 85 informants the data were statistically analyzed by using suitable statistical tools such as Use Value (UV), Informant Consensus Factor (ICF), Fidelity Value (FL) and various ranking methods.

Variation of stable carbon and nitrogen isotopes ratio in Ficus tikoua and their linkage to its specific pollinator

The interactions between figs and their pollinators are among the most specialized examples of mutualism between plants and insects. Based on their life-histories and obligate mutualism, it is reasonable to expect an environmentally-dependent trophic cascade exists between figs and their pollinators. Understanding the mechanisms involved in soil-plant-pollinator trophic cascade relationships will advance our knowledge of how obligate mutualist systems respond to environmental change. We sampled rhizosphere soil, leaves, syconia, and fig wasps (Ceratosolen) of a dioecious prostrate shrub, Ficus tikoua from southwestern China, and measured their carbon (δ13C) and nitrogen (δ15N) stable isotope ratios. The mean leaves δ13C values of F. tikoua were -28.86 ± 1.24%, which suggests it is a typical C3 plant. We detected a significant difference for δ13C and δ15N values of F. tikoua among different populations related to environmental factors such as longitude, altitude, and annual average temperature. The δ13C values showed a significantly positive correlation between fig wasps and host. The δ15N in fig wasps were 3.4% higher than those in F. tikoua, and were positively correlated with δ15N in leaves. These results indicated that fig wasps were feeding on F. tikoua. Moreover, the δ15N values among soil, leaves, and syconia showed significantly positive correlations, indicating the trophic linkage among soil-plant-pollinators. In summary, we noted that environmental factors shaped population variations in stable isotopic patterns of F. tikoua, and such variations drove stable isotopic signatures of its specific pollinators by trophic cascade. Future environmental changes could potentially impact the maintenance and stability of this highly specific pollination system of figs and fig wasps.

Shading decreases and delays NDVI and flowering of prostrate Arctic shrubs

Increases in shrub growth and canopy cover are well documented community responses to climate warming in the Arctic. An important consequence of larger deciduous shrubs is shading of prostrate plant species, many of which are important sources of nectar and berries. Here, we present the impact of a shading experiment on two prostrate shrubs, Vaccinium vitis-idaea L. and Arctous alpina L., in northern Alaska over two growing seasons. We implemented three levels of shading (no shade, 40% shade, and 80% shade) in dry heath and moist acidic tundra. Plots were monitored for soil moisture content, surface temperature, normalized difference vegetation index (NDVI), and flowering. Shading was shown to, on average, lower surface temperature (0.7 °C to 5.3 °C) and increase soil moisture content (0.5% to 5.6%) in both communities. Both species- and plot-level NDVI values were delayed in timing of peak values (7 to 13 days) and decreased at the highest shading. Flower abundance of both species was lower in shaded plots and peak flowering was delayed (3 to 8 days) compared with controls. Changes in timing may result in phenological mismatches and can impact other trophic levels in the Arctic as both the flowers and resulting berries are important food sources for animals.

Quantitative Ethnobotany of Medicinal Plants Used by Indigenous Community in the Munnar Forest Division, Kerala, India

The quantitative ethnobotany deals with the computation of the importance of the plants and vegetation to people. It helps in quantification of qualitative data in the biological and social science. The various quantitative tools in ethnobotany help in the calculation of plant taxon. Ethnobotanical approach provide data which is agreeable to the hypothesis-testing, subsequent statistical validation and comparative analysis. The traditional source of medicinal plants is an important way for daily curative uses in the rural area throughout Kerala. Moreover, among the plant studied habit wise analyzed they are 12 herbs, 13 shrubs, 12 trees and each one of climbing shrub, twining shrub, prostrate shrub, climber. The status of plants are also analyzed and recorded as 26 are common, 14 are rare, 5 are common & Cultivated and 2 are sporadic are described under this study. In this communication, the informations got from the rural inhabitant were compared with the already existing literature. The medicinal plants used by people are arranged alphabetically followed by Botanical name, Family name, Voucher specimen number, Local name, Unani name, Part used, Mode of preparation and Disease cured are discussed. The data were collected randomly from tribal and traditional healers of 85 informants the data were statistically analyzed by using suitable statistical tools such as Use Value (UV), Informant Consensus Factor (ICF), Fidelity Value (FL) and various ranking methods.

Total Carotenoid, Flavonoid and Phenolic Compounds Concentration in Willowleaf Cotoneaster (Cotoneaster Salicifolius Franch.) Fruits

Abstract Willofleaf cotoneaster (Cotoneaster salicifolius Franch.) is a low, prostrate shrub, grown in Romania as an ornamental plant. Its fruits are small, ovoid pomes. Fruit tissues were analyzed for total carotenoid content (through acetone extraction and spectrophotometry), flavonoid content (methanol extraction and spectrophotometry) and total concentration of phenolic and polyphenolic compounds (methanol extraction and spectrophotometric Folin-Ciocâlteu method). C. salicifolius fruits analyzed contained an average of 311.50 mg/kg DW carotenoids (heat-dried fruits – only 100.25 mg/kg). Average flavonoid concentration was 9,777.62 mg/kg in fresh frozen fruits and 4,574 mg/kg in dried ones. 25,056.09 mg/kg GAE was the average concentration of total phenolics in fresh fruits, while dry fruit powder contained 5,271 mg/kg GAE. These concentrations of bioactive compounds are comparable, or even have a higher than in pomes belonging to related species, including domestic cultivars of rowanberry (Sorbus sp.), wild Sorbus species, firethorns (Pyracantha sp.), or other studied cotoneasters. This shows a significant potential for these pomes, requiring further investigation. However, heat-drying was found to be an unsuitable processing method for these fruits, since it led to a 53.22-78.94% decrease in bioactive compounds concentrations.

ХРОНОГРАФИЧЕСКАЯ ИЗМЕНЧИВОСТЬ ФИТОМАССЫ ЯБЛОНИ, ВЫРАЩИВАЕМОЙ В СТЛАНЦЕВОЙ ФОРМЕ В ПРИГОРОДНОЙ ЗОНЕ КРАСНОЯРСКА

The article presents the results of studies of the aboveground phytomass of domestic apple (Malus domestica Borkh) at 14-year and 113-year biological age, which were carried out on the basis of Krutovsky Botanical Garden in the suburban area of Krasnoyarsk. The features of phytomass distribution by fractional composition have been established for the first time for apple trees grown in Siberia in prostrate shrub form. From 10 to 13 leaves with an average area of 26 cm2 and an absolutely dry weight of 0.34 g are formed on the annual shoots of prostrate shrub apple trees. During the formation of fruit trees in the form of "Krasnoyarsk prostrate shrub", three or four main skeletal branches are left. The average model branch of a 14-year-old tree has a length of 3.4 m and a diameter of 7.6 cm at the point of attachment to the trunk; its weight is 1.4 kg in an absolutely dry state. The aboveground phytomass of a tree is 9.7 kg (on average) in an absolutely dry state. At the same time, leaves account for 12% of the aboveground phytomass, stem - 16.6%, branches - 71.4%. With regular pruning of the crown to maintain the prostrate shrub form of cultivation in Krutovsky Botanical Garden, by the age of 14, the phytomass of the crown decreases by 30-33%. The average model branch in a 113-year-old apple tree, when grown in prostrate shrub form, has a length of 6.4 m and a diameter at the base of 26.7 cm. Its weight in an absolutely dry state is 51.9 kg. The phytomass of the aboveground part of a 113-year-old apple tree averages 164 kg in an absolutely dry state, being distributed by fractions: 1.8% (leaves), 3.4% (stem) and 94.8% (branches), respectively

Structural traits of woody plants and geomorphological conditions to the vegetation recovery at Ksudach caldera (Southern Kamchatka) since the explosive eruption in 1907

This study considers the restoration of the plant cover destroyed by a catastrophic volcano eruption in the south of Kamchatka Peninsula (the Ksudach caldera, Shtyubel cone), with a particular attention to the role of woody plants. It aims to qualitatively estimate (at a qualitative level) the rate of the primary succession development depending on the microrelief and the modern relief-forming processes. The vegetation recovery in the caldera after the Shtyubel cone eruption 109 years ago proceeds slowly and irregularly. It proceeds most slowly on a thick tephra mantle continuously disturbed by water and wind erosion, lahars, debris flows, landslides, etc. Such conditions are most typical of the western part of the caldera dominated by pumice fields with occasional patches of pioneer herbs and dwarf shrubs. Alpine tundra communities with gradually expanding patches of shrub alder develop in the southern, eastern and northeastern parts of the Ksudach caldera. Since 1997 the area of the shrub alder communities has increased by 1.9 times, while the alpine tundra — by 1.3 times only. The woody plants (dwarf shrubs and prostrate shrubs) are of particular importance in the process of the vegetation recovery on pumice fields. We suggest that the bark thickness of woody plants is an integrated indicator, which may serve for estimating the state of ecosystem in the course of the primary succession development on juvenile sediments. The extremely inhospitable environments cause changes in physiological processes in the plant body and in its bark in particular. The results show that woody plants have a “thin” bark and develop some structural-functional arrangements for keeping bark tissues at their minimum. So, the woody plant structure and the rate of changes in plant communities are under control of the geomorphic conditions and primarily — of physicochemical features of the pyroclastic cover.

Nutrient deposition on Arctic fox dens creates atypical tundra plant assemblages at the edge of the Arctic

AbstractQuestionsIn most ecosystems, some organisms can be considered ecosystem engineers because they modify their physical environment in a way that can affect many other organisms. Nutrient deposition may be extremely important as an ecosystem engineering activity in nutrient‐limited environments, but this mechanism remains understudied. In low‐Arctic tundra, a region characterized by continuous permafrost, low‐nutrient soils, and slow nutrient turnover, Arctic foxes (Vulpes lagopus) concentrate nutrients on their dens through faecal deposition and feeding their young. This nutrient concentration enhances productivity in patches on the landscape, likely creating a unique habitat for a variety of plants, and could have cascading effects on the distribution and diversity of vegetation on the tundra.LocationLow‐Arctic tundra in Wapusk National Park, Manitoba, Canada.MethodsWe quantified differences in vegetation composition between 20 fox dens and adjacent control sites.ResultsPlant growth form differed greatly between dens, which were dominated by deciduous grasses near the coast and erect shrubs farther from the coast, and control sites, which were dominated by evergreen prostrate shrubs. Dens also had more forb cover and less cover of lichens, mosses, and sedges. Species composition also varied greatly between control and den areas, with 17 of the 20 species found in at least 10% of the sampled sites being indicator species for dens or control sites.ConclusionsBy providing habitat for plants reliant on higher nutrient availability not typical of tundra heath, Arctic foxes enhance the biodiversity of the region. These erect plants may also help create new habitat by retaining snow on normally windswept beach ridges. Overall, this study illustrates the broader impacts of predators on diversity and community composition through mechanisms other than predation.

A raster version of the Circumpolar Arctic Vegetation Map (CAVM)

Land cover maps are the basic data layer required for understanding and modeling ecological patterns and processes. The Circumpolar Arctic Vegetation Map (CAVM), produced in 2003, has been widely used as a base map for studies in the arctic tundra biome. However, the relatively coarse resolution and vector format of the map were not compatible with many other data sets. We present a new version of the CAVM, building on the strengths of the original map, while providing a finer spatial resolution, raster format, and improved mapping. The Raster CAVM uses the legend, extent and projection of the original CAVM. The legend has 16 vegetation types, glacier, saline water, freshwater, and non-arctic land. The Raster CAVM divides the original rock-water-vegetation complex map unit that mapped the Canadian Shield into two map units, distinguishing between areas with lichen- and shrub-dominated vegetation. In contrast to the original hand-drawn CAVM, the new map is based on unsupervised classifications of seventeen geographic/floristic sub-sections of the Arctic, using AVHRR and MODIS data (reflectance and NDVI) and elevation data. The units resulting from the classification were modeled to the CAVM types using a wide variety of ancillary data. The map was reviewed by experts familiar with their particular region, including many of the original authors of the CAVM from Canada, Greenland (Denmark), Iceland, Norway (including Svalbard), Russia, and the U.S. The analysis presented here summarizes the area, geographical distribution, elevation, summer temperatures, and NDVI of the map units. The greater spatial resolution of the Raster CAVM allowed more detailed mapping of water-bodies and mountainous areas. It portrays coastal-inland gradients, and better reflects the heterogeneity of vegetation type distribution than the original CAVM. Accuracy assessment of random 1-km pixels interpreted from 6 Landsat scenes showed an average of 70% accuracy, up from 39% for the original CAVM. The distribution of shrub-dominated types changed the most, with more prostrate shrub tundra mapped in mountainous areas, and less low shrub tundra in lowland areas. This improved mapping is important for quantifying existing and potential changes to land cover, a key environmental indicator for modeling and monitoring ecosystems. The final product is publicly available at www.geobotany.uaf.edu and at Mendeley Data, DOI: 10.17632/c4xj5rv6kv.1.

Water movement via adventitious roots of the prostrate shrub Juniperus sabina in semiarid areas of China

The prostrate evergreen shrub Juniperus sabina L. is an important tree species for revegetation in semi-arid areas of China. The root system of J. sabina comprises a main root system, which can reach deeper soil, and adventitious roots that mainly extend in the surface soil. In our previous studies, water movement between different soil layers via these root systems associated with rainfall-induced vertical heterogeneity in soil moisture has been suggested by sap flow analysis. In this study, to confirm the existence of water movement from the deeper soil to the surface soil (i.e., hydraulic redistribution) under the progression of drying after rainfall, we controlled soil moisture in six potted J. sabina plants. On the assumption of drying after rain, the main roots continued to receive irrigation and only the irrigation on the adventitious root part was stopped. When drying had sufficiently progressed and the decline in soil moisture had stabilized, 18O-labeled water was irrigated at the main roots for 7-9 days. The 18O-labeled water was detected from the adventitious roots and soil on the adventitious root through the analysis of the oxygen stable isotope ratio of water. Sap flow was also measured during the experiment. Two sensors were implanted on each studied plant: one in the base of the decumbent stem, located between the main root system and adventitious roots, and the other distal to the decumbent stem. Sap flow occurred at nighttime only in the base of the decumbent stem during drying of the adventitious root. These results suggest the existence of water movement from moist soil to dry soil via the main and adventitious roots (hydraulic redistribution), which increased with the progression of drought.

Responses of the Clonal Florida Endemic Shrub Polygonella myriophylla to Fire and Mechanical Disturbance

There is an unsettled debate on the benefits of mechanical disturbance for native species in fire-prone habitats. We compared the demographic effects of fire and mechanical treatments (Gyro-tracing) on Polygonella myriophylla, a prostrate clonal shrub listed as endangered and narrowly endemic to pyrogenic scrub ecosystems in south-central Florida. This species is commonly found in gaps within a matrix dominated by resprouting shrubs, but also occurs under other shrubs and along the shoulders of adjacent road-side habitats. We designed and executed a replicated (that plots per treatment, 1 ha per plot; total 147 initial plants) experiment including plots burned, mechanically chopped, with both treatments and without treatments at the Lake Wales Ridge Wildlife and Environmental Area - Carter Creek in Highlands County, central Florida (2005-2008; treated in summer of 2005). Cumulative mortality of standing P. myriophylla after 3 y was higher in burned plots (> 80%) than in chopped-only and untreated plots (∼ 50 % and ∼ 40 % respectively). Post disturbance growth in canopy area among the surviving plants was consistently higher in mechanically disturbed plots compared to untreated plots and intermediate burned conditions. We found three putative seedlings, accounting for less than 3% of the initial genets, before treatment application, but many seedlings after treatments. Seedling recruitment (∼ 90) post-treatment was higher in disturbed plots, highest when both treatments occurred together, and almost null in untreated plots. Recruitment was highest in the first-year post disturbance (70%), decreasing in subsequent years. Disturbances may improve the persistence of P. myriophylla by increasing recruitment and individual growth, however; fire and mechanical disturbance should be used with caution for this species given many plants died during treatment.

Growth delay by winter precipitation could hinder Juniperus sabina persistence under increasing summer drought

Plants in Mediterranean mountains are particularly vulnerable to climatic change. In these environments, low temperature is combined with water shortage during summer, and as a result, the positive effect of global warming theoretically expanding the growing season length may be counterbalanced by rising drought stress. These circumstances may be exacerbated in the rear edge of species distribution, where warmer conditions occur. Here, we examined the climate-growth relationships of Juniperus sabina, a major prostrate shrub above the treeline in Mediterranean mountains, to investigate climate sensitivity and long-term signals stability in four rear-edge populations from southern Spain. We demonstrate that, over recent decades, local climatic conditions have modulated the response of J. sabina secondary growth to the ongoing climate change. We observed a negative effect of winter-spring moisture on secondary growth that suggests a limitation for earlier growth activity at higher elevation, potentially hindering the ability of J. sabina to compensate forthcoming increases in summer drought. At the driest site, we also detected a positive effect of October precipitation, suggesting a second growth pulse by early autumn. Our results provide an example of how local climatic conditions may limit plastic responses of secondary growth to climatic variability. The implications of growth limitation in J. sabina exceed the species-scale level, since these prostrate shrubs play a critical role as nurse plants and local biodiversity foci in Mediterranean mountains.

Effect of maturation time on dormancy and germination of Citrullus colocynthis (Cucurbitaceae) seeds from the Arabian hyper-arid deserts

BackgroundLight and temperatures of germination greatly affect germination of several Cucurbitaceae species. Environmental conditions prevailing at seed maturation time can affect dormancy and germination requirements. Citrullus colocynthis seeds have a deep dormancy. This perennial prostrate shrub grows all over the year in the arid Arabian deserts. We explored if seed dormancy and germination requirements of C. colocynthis depend on time of fruit collection. Matured seeds were collected at five different times during 2014/2015 year from a population around Dubai city. Fresh seeds were germinated at three temperature regimes in both continuous darkness and alternating 12 h light/12 h darkness. Impacts of seed storage and other treatments on germination were applied on seeds collected in March and exhibited deep dormancy.ResultsMarch collected seeds almost did not germinate in both light and dark at the three temperatures, but those of the other collections responded differently to both light and temperatures. At the lowest temperatures, seeds of all collections did not germinate in light, but those of June, October and December collections germinated in dark. There were negative correlations between final germination and seed length, width, mass and coat thickness. Physical scarification, water soaking and seed storage did not break dormancy of March collection.ConclusionsGermination of C. colocynthis is very sensitive to light and incubation temperature as well as to the environmental conditions associated with the time of seed maturation. It is important to investigate the effects of environmental factors prevailing during seed maturation under controlled conditions to understand exact reasons for unusual seed dormancy and germination requirements of C. colocynthis, which seems to be very sensitive to maternal environment.

Wind Distortion in Alpine and Subantarctic Plants is Constant among Life Forms but does not Necessarily Reflect Prevailing Wind Direction

ABSTRACTWoody plants in windy environments have been used as indicators of prevailing wind direction, because wind can influence plant growth form. We investigated whether non-woody plants also display consistent prevailing wind deformation by observing the direction of asymmetry in growth form of cushion plants, graminoids, and prostrate shrubs growing in highly wind-exposed treeless environments in alpine Tasmania and subantarctic Macquarie Island. Wind distortion of individual plants was inferred from vertical photographs of feldmark and alpine heath vegetation. High correspondence in growth direction between plants of different types suggests a uniform wind influence on plants at the local scale (within <2 m). Dominant wind direction inferred from plant distortion was not consistent with the strongest and most frequent winds. On a relatively dry mountain with shallow soils the plants responded to strong northwest winds in an apparent desiccation response. Elsewhere, they responded to strong southwest winds in an apparent ice abrasion response. We conclude that, in maritime alpine and subantarctic environments, the direction of wind distortion can be measured using any of shrubs, graminoids, or cushion plants, but that this direction is not necessarily a response to the prevailing strongest winds, but rather winds that most damage foliage, the cause of damage varying with environmental context.

The southern coastal Beringian land bridge: cryptic refugium or pseudorefugium for woody plants during the Last Glacial Maximum?

AbstractAimThe Bering Land Bridge (BLB) connected Asia and North America during glacial periods, supported a diverse ecosystem of now‐vanished megafauna, and is a proposed glacial refugium. This study tests whether southern coastal Beringia was a refugium for woody taxa during the Last Glacial Maximum (LGM) and hypotheses about habitats available on the BLB before and after megafaunal extinction.LocationSt. Paul Island, Alaska.MethodsWe analysed sediment cores from the Lake Hill, with a new age model anchored by 18 radiocarbon dates and multiple palaeoecological indicators (sedimentary ancient DNA [sedaDNA], macrobotanical fossils, and pollen) for the presence/absence of four woody genera: Picea, Betula, Alnus and Salix. We reconstructed vegetation history and compare St. Paul tundra composition to mainland counterparts.ResultsSt. Paul has been continuously occupied by graminoid‐forb tundra with prostrate shrubs (Salix, Ericaceae) since 18,000 years before present (yr bp). Fossil pollen of Picea, Pinus, Betula and Alnus is present in the Lake Hill sediments at low relative abundances and accumulation rates, consistent with long‐distance transport. Macrobotanical fossils and sedaDNA analyses do not support Picea, Betula and Alnus presence. The St. Paul modern and fossil pollen assemblages are compositionally unlike mainland counterparts, but most closely resemble Arctic herbaceous tundra. Stratigraphically constrained cluster analysis indicates no major change in the vegetation after woolly mammoth extinction at 5600 yr bp, although Poaceae, Cyperaceae, Equisetum and forb abundances increase.Main conclusionsThis study strongly indicates that St. Paul and, by implication, southern coastal Beringia were not refugia for woody taxa during the LGM. The persistence of prostrate shrub‐graminoid tundra supports interpretations that herbaceous tundra prevailed on southern Beringia during the LGM, whilst not ruling out the possibility of mesic shrub tundra in the interior. This herbaceous tundra supported an island refugium for woolly mammoth for 8000 years, showing no major vegetation composition changes after extinction.

Development of 14 polymorphic microsatellite loci for Ficus tikoua (Moraceae).

Premise of the study:Polymorphic microsatellite markers were developed to facilitate studies on the fine-scale population genetic structure of Ficus tikoua (Moraceae), a prostrate shrub known to have highly restricted gene flow.Methods and Results:Microsatellite primers were developed using the biotin-streptavidin capture method and scanned for polymorphism within 76 individuals sampled from three natural F. tikoua populations. Fourteen loci were shown to be polymorphic, with allele numbers ranging from three to 16. The observed and expected heterozygosity in the three populations ranged from 0 to 1 and from 0 to 0.87, respectively. Substantial divergence was found among the populations at some loci. All loci can be successfully amplified in at least eight other Ficus species, indicating good transferability within the genus.Conclusions:The 14 microsatellite loci will be a helpful tool for assessing the fine-scale genetic structure of F. tikoua.

Isolation and characterization of 13 polymorphic microsatellite loci for the fig wasp, Ceratosolen sp. (Hymenoptera: Agaonidae)

Fig wasps are short-lived, delicate and weak-flying. Their long-distance dispersal is highly dependent on the air flow above the canopy. The life forms of their host Ficus species determine their place of release, and so their ability of entering the fast-flowing air above the canopy. Ficus tikoua Bur. is a dioecious prostrate shrub with partially buried figs. Its breeding system and growth form are consistent with limited dispersal ability and high genetic differentiation between populations of its pollinating fig wasps. Highly polymorphic microsatellite loci will allow detection of fine-scale genetic structure in its pollinator, and elucidate co-evolutionary dynamics with its host. We developed 13 polymorphic microsatellite loci for Ceratosolen sp. (Agaonidae), the obligate pollinating fig wasp of F. tikoua. The validity and polymorphism of each primer was tested in three populations from Southwest China. No significant linkage disequilibrium was detected between any locus pairs. Overall, allele numbers per locus ranged from 2 to 17. At population level, the observed and expected heterozygosities ranged from 0 to 0.833 and from 0 to 0.840, respectively. These polymorphic loci will be a helpful tool for screening genetic variation within the pollinator of F. tikoua and relating variation to that of its host.