Subalpine Environments Research Articles

Water Niche Characteristics of Subalpine Shrub in Eastern Qilian Mountains, China

ABSTRACTThe investigation and research of plant niche provide new ideas for understanding the extent of resource utilization by plants and the coexistence relationship among species. Taking the subalpine shrub plants in the eastern Qilian Mountains as the research object, the contribution rate of each potential water source to the shrub plants was estimated using the Bayesian mixed modelling (MixSIAR), and the spatial and temporal characteristics of their water niche were analysed quantitatively using Levins' niche breadth index and Pianka's niche overlap index. The results showed that shrub plants on the semi‐shady slope exhibited larger water niche breadth and overlap compared to those on the semi‐sunny slope, which indicated that shrub plants on the semi‐shady slope had strong adaptability to the water environment, but the competition for water among them was more intense. Furthermore, the water niche breadth and overlap of shrub plants decreased with the promotion of the growth stage, which was related to changes in precipitation and plant physiological characteristics during their growth cycle. Among the studied species, Potentilla fruticosa Linn., Salix oritrepha Schneid., Salix cupularis Rehd. and Rhododendron thymifolium Maxim. had broader water niche breadth in different habitats, indicating superior adaptability to the subalpine environment. Despite that the water niche overlap among shrub plants was high and their competition for water resources was intense, there was no absolute positive correlation between niche breadth and overlap. The research can provide a theoretical reference for the rational allocation of species during vegetation restoration in Qilian Mountain National Park.

Reproductive Traits in Two Alpine Endemic Species of Campanulaceae

Alpine plants are well adapted to environments with extreme conditions – low temperatures, a short growing season, increased air humidity and precipitation, and are therefore of particular interest for research. The aim of the present study is to reveal the main reproductive characteristics of two endemic species of the family Campanulaceae, namely Campanula orbelica (Balkan endemic) and Jasione bulgarica (Bulgarian endemic). The main features of the reproductive biology (embryological features, type of reproduction) were established based on the study of micro- and macrosporogenesis and the development of male and female gametophytes. The established features of the reproductive structures and processes characterized C. orbelica and J. bulgarica as sexually reproducing species. Despite the extreme conditions of existence, the studied species presented normal generative progresses leading to the formation of pollen and embryo, which ensures their successful reproduction, populations stability and their distribution in the subalpine environment. In addition, the genome size of C. orbelica was studied by flow cytometry. The estimated genome size varied in the range 1C = 1.34–1.38 pg. No deviation in the ploidy level was found in 22 specimens fresh leaves of which were collected from different parts of the Rila and Pirin Mts.

Effects of experimental warming on floral scent, display, and rewards in two subalpine herbs.

Floral volatiles, visual traits, and rewards mediate attraction and defense in plant-pollinator and plant-herbivore interactions, but these floral traits may be altered by global warming through direct effects of temperature or longer term impacts on plant resources. We examined the effect of warming on floral and leaf volatile emissions, floral morphology, plant height, nectar production, and oviposition by seed predators. We used open-top chambers that warmed plants in the field +2-3 °C on average (+6-11 °C increase in daily maxima) for 2-4 weeks across 1-3 years at 3 sites in Colorado, USA. Volatiles were sampled from two closely related species of subalpine Ipomopsis with different pollinators: I. aggregata ssp. aggregata, visited mainly by hummingbirds, and I. tenuituba ssp. tenuituba, often visited by hawkmoths. While warming had no detected effects on leaf volatiles, the daytime floral volatiles of both I. aggregata and I. tenuituba responded in subtle ways to warming, with impacts that depended on the species, site, and year. In addition to the long-term effect of warming, temperature at the time of sampling independently affected the floral volatile emissions of I. aggregata during the day and I. tenuituba at night. Warming had little effect on floral morphology for either species, and no effect on nectar concentration, maximum inflorescence height, or flower redness in I. aggregata. However, warming increased nectar production in I. aggregata by 41%, a response that would attract more hummingbird visits, and reduced oviposition by fly seed predators by at least 72%. Our results suggest that floral traits can show different levels of plasticity to temperature changes in subalpine environments, with potential effects on animal behaviors that help or hinder plant reproduction. They also illustrate the need for more long-term field warming studies, as shown by responses of floral volatiles in different ways to weeks of warming versus temperature at the time of sampling.

Near-field variability of evaposublimation in a montane conifer forest

Methods that combine in-situ measurements, statistical methods, and model simulations with remotely sensed data provide a pathway for improving the robustness of surface flux products. For this research, we acquired eddy-covariance fluxes along a five-tower transect in a snowy montane forest over three consecutive winters to characterize near-field variability of the subcanopy environment. The novel experiment design enabled discriminating near-field evaposublimation sources. Boosted regression trees reveal that the predictive capacity of state variables change with season and storm cycle frequency. High rates of post-storm evaposublimation of canopy-intercepted snow at this site were constrained by short residence time of snow in the canopy due to throughfall and melt. The snow melt-out date for open vs. closed canopy conditions depended on total snowfall accumulation. Compared with low accumulation years, the snow melt-out date under the dense canopy during the high accumulation winter was later than for the open area, as shading became more important later in the season. The field experiments informed an environmental response function that was used to integrate ERA5-Land latent heat flux data at 20-km nominal resolution with USFS Tree Canopy Fraction data at 30-m resolution and showed near-field flux variability that was not resolved in model simulations. Previous evaposublimation results from experiments in alpine and subalpine environments do not directly translate to a montane forest due to differences in process rates.

Evolutionary Processes Shaping Postglacial Gene Pools of High-Altitude Forests: Evidence from the Endemic Eucalypts of Tasmania

Climatic changes during the Pleistocene were responsible for dramatic redistributions of plant species worldwide. On the rugged southern hemisphere island of Tasmania, temperature increases following the last glaciation saw upslope migration of climatically suitable species from lowland refugia and the expansion of eucalypt-dominated forests and woodlands in the Central Highlands. We integrate multiple lines of evidence (chloroplast and nuclear DNA markers, seedling morphology, and survival in common garden experiments) from a group of closely related endemic eucalypts (the alpine white gums) to argue that (i) the Central Highlands of the island were colonised by multiple glacial refugia with hybridisation among species and previously separated populations, and (ii) natural selection has filtered the admixed populations, resulting in local adaptation to the harsh sub-alpine environment. Chloroplast haplotype diversity decreased and nuclear microsatellite diversity increased with altitude, chloroplast sharing among taxa was common, and nuclear DNA differentiation of morphologically distinct taxa was lower in the Central Highlands compared with lowland regions. Local adaptation in the highlands was signalled by evidence from (i) a glasshouse trial in which directional selection (QST > FST) had shaped seedling morphological trait variation and (ii) population survival differences in 35-year-old reciprocal plantings along the major environmental gradients. We conclude that the evolutionary response of these island endemic trees to past climate change has involved the interplay of both hybridisation and natural selection, highlighting the importance of maintaining species interactions under future climate change.

Diversity and community structure of ectomycorrhizal mycorrhizal fungi in roots and rhizosphere soil of Abies koreana and Taxus cuspidata in Mt. Halla

In this study, the roots and rhizosphere soil of Abies koreana and Taxus cuspidata were collected from sites at two different altitudes on Mt. Halla. Ectomycorrhizal fungi (EMF) were identified by Illumina MiSeq sequencing. The proportion of EMF from the roots was 89% in A. koreana and 69% in T. cuspidata. Among EMF in rhizosphere soils, the genus Russula was the most abundant in roots of A. koreana (p < 0.05). The altitude did not affect the biodiversity of EMF communities but influenced fungal community composition. However, the host plants had the most significant effect on EMF communities. The result of the EMF community analysis showed that even if the EMF were isolated from the same altitudes, the EMF communities differed according to the host plant. The community similarity index of EMF in the roots of A. koreana was higher than that of T. cuspidata (p < 0.05). The results show that both altitude and host plants influenced the structure of EMF communities. Conifers inhabiting harsh sub-alpine environments rely strongly on symbiotic relationships with EMF. A. koreana is an endangered species with a higher host specificity of EMF and climate change vulnerability than T. cuspidata. This study provides insights into the EMF communities, which are symbionts of A. koreana, and our critical findings may be used to restore A. koreana.

Legume germination is delayed in dry soils and in sterile soils devoid of microbial mutualists: Species-specific implications for upward range expansions.

Climate change is affecting species and their mutualists and can lead to the weakening or loss of important interspecific interactions. Through independent shifts in partner phenology and distribution, climatic stress can separate mutualists temporally or spatially, leading to alterations in partner functional traits and fitness. Here, we explored the effects of the loss of microbial mutualists on legume germination success and phenology. In particular, we assessed the effects of mutualism loss via soil sterilization, increased drought, and introduction to novel soils found beyond the current distributions of two focal legume species in subalpine environments. Through common garden experiments in controlled environments, we found evidence that soil sterilization (and consequent microbial absence) and dry soils caused species‐specific phenological delays of 2–5 weeks in germination, likely as a result of interaction loss between legumes and specialized germination‐promoting soil microbes, such as mutualistic rhizobia. Delays in germination caused by a mismatch between legumes and beneficial microbes could negatively affect legume fitness through increased plant–plant competition later in the season. Additionally, we found evidence of the presence of beneficial microbes beyond the current elevational range of one of our focal legumes, which may allow for expansion of the leading edge, although harsh abiotic factors in the alpine may hinder this. Alterations in the strength of soil microbe‐legume mutualisms may lead to reduced fitness and altered demography for both soil microbes and legumes.

The earlier the better? Nesting timing and reproductive success in subalpine cavity-nesting bees.

Reproductive timing can affect an organism's production of offspring and its offspring's success, both of which contribute to its overall fitness. In seasonal environments, the timing of reproductive activity may be restricted to short periods of the year owing to numerous potential selective pressures such as variation in daylength, weather, food availability, predation or competition. We documented the relationships between reproductive timing and individual reproductive success (total reproductive output and offspring success) in subalpine populations of five cavity-nesting solitary bee species. We also examined the relationships between bee reproductive success and environmental variables that are likely ultimate drivers of bee phenology in subalpine environments (i.e. seasonality of floral resource abundance and temperature). Over 6years, we recorded solitary bee nesting timing, egg production and offspring success using artificial nesting structures ('trap-nests') established at multiple study sites. We also quantified floral resources and recorded temperature throughout growing seasons. Bees nesting earlier in the season exhibited greater reproductive success. Reproductive output generally increased with floral abundance, although this relationship was weak and only significant for some bee species. Elevated temperatures were associated with increased nest construction rate, but not with greater reproductive output. These contrasting effects of temperature may have been driven by the negative relationship between temperature and bee longevity. Bees who nested for shorter durations of time (a proxy for longevity) produced fewer offspring, and individuals exhibiting the shortest nesting durations were also those that began nesting late in the season. Overall, bees who initiated nesting early and sustained activity for a long duration had the highest reproductive output. This work documents the relationship between reproductive phenology and fitness in wild insect populations and highlights the ways in which organisms can cope with the challenges of living in seasonal and highly variable environments.

Lineage-specific plastid degradation in subtribe Gentianinae (Gentianaceae).

The structure and sequence of plastid genomes is highly conserved across most land plants, except for a minority of lineages that show gene loss and genome degradation. Understanding the early stages of plastome degradation may provide crucial insights into the repeatability and predictability of genomic evolutionary trends. We investigated these trends in subtribe Gentianinae of the Gentianaceae, which encompasses ca. 450 species distributed around the world, particularly in alpine and subalpine environments. We sequenced, assembled, and annotated the plastomes of 41 species, representing all six genera in subtribe Gentianinae and all main sections of the species‐rich genus Gentiana L. We reconstructed the phylogeny, estimated divergence times, investigated the phylogenetic distribution of putative gene losses, and related these to substitution rate shifts and species’ habitats. We obtained a strongly supported topology consistent with earlier studies, with all six genera in Gentianinae recovered as monophyletic and all main sections of Gentiana having full support. While closely related species have very similar plastomes in terms of size and structure, independent gene losses, particularly of the ndh complex, have occurred in multiple clades across the phylogeny. Gene loss was usually associated with a shift in the boundaries of the small single‐copy and inverted repeat regions. Substitution rates were variable between clades, with evidence for both elevated and decelerated rate shifts. Independent lineage‐specific loss of ndh genes occurred at a wide range of times, from Eocene to Pliocene. Our study illustrates that diverse degradation patterns shape the evolution of the plastid in this species‐rich plant group.

Breeding biology and long-term population dynamics of the Pied Flycatcher Ficedula hypoleuca in Skibotn, Northern Norway

Abstract. The breeding biology and population dynamics of the Pied Flycatcher Ficedula hypoleuca in pine, mixed and deciduous forests in Skibotn, Northern Norway (69°20’N, 20°20’E), was studied during 33 years (1987–2019; in total 1775 completed first clutches). It was a period during which summer temperatures remained relatively stable, but late spring (May) temperatures tended to become warmer. The number of breeding pairs declined over the study period but varied less than in populations living in more harsh subalpine environments. In spite of the northern location, females started to lay eggs in a relatively late phenological phase of the environment and in relatively warm weather. The date of birch leafing and the date of egg-laying advanced during the study period, and they correlated with each other. Mean clutch size was 6.4 eggs, and mean number of fledglings/nest 4.6. Date of egg-laying was earlier and clutch size larger in deciduous forests than in pine and mixed forests, but this did not translate into better fledgling productivity. The main causes of nesting failure were predation by small mustelids and starvation in warm and dry summers. However, in the long run the population seemed to be able to maintain itself without immigration, i.e., act as a source population. The possibility that during warm climate periods of the past, breeding biology and population dynamics of Pied Flycatchers over large geographical areas might have resembled those in Skibotn is discussed.&#x0D; &#x0D; Cover photo: “Mummified” Pied Flycatcher nestling (age about 10 days) starved to death in Skibotn in the warm and dry summer of 1988. Photo: Antero Järvinen.

Climate-human interactions contributed to historical forest recruitment dynamics in Mediterranean subalpine ecosystems.

Long-term tree recruitment dynamics of subalpine forests mainly depend on temperature changes, but little is known about the feedbacks between historical land use and climate. Here, we analyze a southern European, millennium-long dataset of tree recruitment from three high-elevation pine forests located in Mediterranean mountains (Pyrenees, northeastern Spain; Pollino, southern Italy; and Mt. Smolikas, northern Greece). We identify synchronized recruitment peaks in the late 15th and early 16th centuries, following prolonged periods of societal and climate instability. Major European population crises in the 14th and 15th centuries associated with recurrent famines, the Black Death pandemic, and political turmoil are likely to have reduced the deforestation of subalpine environments and caused widespread rewilding. We suggest that a distinct cold phase in the Little Ice Age around 1450ce could also have accelerated the cessation of grazing pressure, particularly in the Pyrenees, where the demographic crisis was less severe. Most pronounced in the Pyrenees, the enhanced pine recruitment from around 1500-1550ce coincides with temporarily warmer temperatures associated with a positive phase of the North Atlantic Oscillation. We diagnose that a mixture of human and climate factors has influenced past forest recruitment dynamics in Mediterranean subalpine ecosystems. Our results highlight how complex human-climate interactions shaped forest dynamics during pre-industrial times and provide historical analogies to recent rewilding.

Mapping tall shrub biomass in Alaska at landscape scale using structure-from-motion photogrammetry and lidar

Warming in arctic and boreal regions is increasing shrub cover and biomass. In southcentral Alaska, willow (Salix spp.) and alder (Alnus spp.) shrubs grow taller than many tree species and account for a substantial proportion of aboveground biomass, yet they are not individually measured as part of the operational Forest Inventory and Analysis (FIA) Program. The goal of this research was to test methods for landscape-scale mapping of tall shrub biomass in upper montane and subalpine environments using FIA-type plot measurements (n = 51) and predictor variables from imagery-based structure-from-motion (SfM) and airborne lidar. Specifically, we compared biomass models constructed from imagery acquired by unmanned aerial vehicle (UAV; ~1.7 cm pixels), imagery from the NASA Goddard's Lidar, Hyperspectral, and Thermal Airborne Imager (G-LiHT; ~3.1 cm pixels), and concomitant G-LiHT small-footprint lidar. Tall shrub biomass was most accurately predicted at 5 m resolution (R2 = 0.81, RMSE = 1.09 kg m−2) using G-LiHT SfM color and structure variables. Lidar-only models had lower precision (R2 = 0.74, RMSE = 1.26 kg m−2), possibly due to reduced model information content from variable multicollinearity or lower data density. Separate models for upper montane zones with trees and shrubs and subalpine zones with only shrubs were always chosen over single models based on minimization of Akaike's Information Criterion, indicating the need for variable sets robust to overhanging tree canopy. Decreasing point density from UAV (5000–8000 pts. m−2) to the G-LiHT SfM point cloud (500–2000 pts. m−2) had little impact on model fit, suggesting that high-resolution airborne imagery can extend SfM approaches well beyond line-of-sight restrictions for UAV platforms. Overall, our results confirmed that SfM from high-resolution imagery is a viable approach to estimate shrub biomass in the boreal region, especially when an existing lidar terrain model and local field calibration data are available to quantify uncertainty in the SfM point cloud and landscape-scale estimates of shrub biomass.

Phytophthora cinnamomi exhibits phenotypic plasticity in response to cold temperatures

Phytophthora cinnamomi has recently been found in highly diverse and fragile alpine and sub-alpine environments previously considered P. cinnamomi and disease free due to low temperatures. In the laboratory, we investigated the ability of P. cinnamomi isolates to adapt to cold and cause disease under conditions comparable to alpine and sub-alpine environments. Initially, the ability of P. cinnamomi isolates to produce sporangia at 10 °C (2 °C lower than previously reported in the literature) was demonstrated in vitro. The lowest temperature limit for host infection was determined (i.e., 8 °C) and the phenotypic plasticity of isolates was then explored in planta in two successive phenotypic plasticity experiments comparing cold 9, 7.5 °C, and ambient temperature 25 (±5 °C). In the phenotypic plasticity experiment-1, three of the five isolates recovered from plants grown at 9 °C produced sporangia and released zoospores (infective propagules) at 7.5 °C, even lower than determined initially, i.e., 10 °C. No changes were observed in the same set of isolates recovered from plants grown at ambient temperature in the glasshouse as a control, which shows that P. cinnamomi can exhibit phenotypic plasticity and responds rapidly to selection pressure and adapts to new environments. Although P. cinnamomi isolates could produce infective propagules at 7.5 °C in vitro, they could not be recovered from inoculated plants grown at 7.5 °C after 3 months in phenotypic plasticity experiment-2. More work is, therefore, needed to establish disease development by P. cinnamomi at 7.5 °C and below.

Plastic film mulching improves seed germination, seedling development and potential for perenniality of Vicia unijuga under subalpine climate conditions

Our aim was to identify temperature and moisture modifications needed for improvement of seed germination, growth and establishment of the protein-rich forage legume Vicia unijuga A.Br. so that it could become large enough and store sufficient root reserves to survive in subalpine conditions. Germination tolerance of scarified V. unijuga seeds to various temperatures and water potentials was tested in the laboratory, and a 3-year field experiment was conducted in the subalpine region of China to evaluate the effects of modified soil temperature and moisture conditions generated by mulching with plastic film and barley straw on seedling emergence, growth, root nutrient reserves and subsequent overwinter performance. The highest germination percentage and rate occurred at the optimum temperature of 15–20°C, which improved these germination traits at low water potentials between –0.6 and –1.0 MPa. Higher soil temperature and water content were recorded in the plastic mulch treatment than in the control and straw mulch treatments. This enhanced establishment and accumulation of biomass and root reserve pools in the plastic mulch treatment, with nearly 100% of the plants surviving overwinter. The relative contribution of soil temperature was greater than of soil-water content to the variation in biomass and root nutrient reserves. Root starch content explained the most variation in overwinter survival. In conclusion, scarified V. unijuga seeds can germinate over a wide range of conditions, including those in the subalpine zone in spring. The plastic mulch treatment provided adequate soil temperature and water resources to improve growth and root starch reserves in first-year plants of V. unijuga, thereby improving overwinter survival in the subalpine environment.

The significance of anthropochory in Hercinothrips femoralis (Thysanoptera: Thripidae) - Short Communication

After the first record of the banded greenhouse thrips, Hercinothrips femoralis (Reuter, 1891) in Slovakia in 2008, a peculiar occurrence in an extreme subalpine environment of Podbanské (High Tatra Mts.), Slovakia, during the summer of the same year was observed. Since this species of exotic thrips is known to be almost sedentary, the mode of dispersal was hypothesized to be related to passive transport via weather currents. According to our observations of unintentional dispersal a test was conducted to research a previously unidentified introduction pathway of this species. Our preliminary results show that passive transport by humans plays a crucial role in the dispersal of H. femoralis.

Population history of European mountain pines Pinus mugo and Pinus uncinata revealed by mitochondrial DNA markers

AbstractThe dwarf mountain pine (Pinus mugo) and the Pyrenean pine (P. uncinata) constitute a pair of closely related coniferous taxa of poorly resolved evolutionary history and affinity, which inhabit numerous stands scattered over subalpine environments of European mountain ranges. The aim of the study was to investigate their phylogeography and mutual relationships, shedding new light on their taxonomy and the past of the alpine flora. Previous evolutionary reconstructions of the mountain pines relied mainly on bi‐parentally or paternally inherited markers that quickly homogenize between populations, showing rather shallow and recent differentiation of gene pools. Therefore, to contrast these pictures, we analyzed diversity and differentiation within a large set of new mitochondrial loci, inherited in maternal line and distributed by seeds at short geographical distances. Samples of the taxa were taken from 27 natural populations representing their range‐wide distributions—17 populations of P. mugo and 10 of P. uncinata. All markers appeared polymorphic, providing a total of 31 multilocus haplotypes. Two of the loci proved to be species‐diagnostic and nearly fixed between analyzed samples. Distribution of mitotypes indicate that allopatric populations of the taxa constitute separate mitochondrial haplogroups, and the two mountain pines have independent evolutionary history. However, introgression of P. mugo mitotypes by P. uncinata specimens revealed in the species contact zone in Western Alps shows that their speciation is not fully completed.

Genomic signatures of high-altitude adaptation in Ethiopian sheep populations.

Ethiopian sheep populations such as Arsi-Bale, Horro and Adilo (long fat-tailed, LFT) inhabit mid to high-altitude areas; and Menz sheep (MZ, short fat-tailed) are adapted to cool sub-alpine environments. In contrast, Blackhead Somali sheep (BHS, fat-rumped) thrive well in arid and semi-arid areas characterized by high temperature and low precipitation. The genomic investigation of Ethiopian sheep populations may help to identify genes and biological pathways enable to adapt to the different ecological conditions. To uncover genomic regions and genes showing evidence of positive selection for altitude adaptation in Ethiopian sheep populations. A total of 72 animals inhabiting high-versus low-altitude environments were genotyped on an Ovine Infinium HD array (~ 600K). Pairwise genetic differentiation (Fst) was calculated in sliding windows of 20 SNPs and the upper 1% smoothed Fst values were considered to represent positive selection signatures. Genes within < 25kb of the most differentiated SNPs were considered as selection candidates. Signatures of selection were detected in genes known to be associated high with altitude adaptation in MZ-BHS pair comparison (PPP1R12A, RELN, PARP2, and DNAH9) and in LFT-BHS pair comparison (VAV3, MSRB3,EIF2AK4, MET, and TACR1). The candidate genes (MITF, FGF5, MTOR, TRHDE, and TUBB3) associated with altitude adaptation and shared between the MZ-BHS and LTF-BHS pair comparisons were also detected as under selection. Further functional analyses reveal that the candidate genes were involved in biological processes and pathways relevant to adaptation under extreme altitudes, including respiratory system development and smoothened signaling pathway. The results of the present study could aid in-depth understanding and exploitation of the underlying genetic mechanisms for sheep and other livestock species adaptation to high-altitude environments.

Forest and lake dynamics in response to temperature, North American monsoon and ENSO variability during the Holocene in Colorado (USA)

Learning how terrestrial environments responded to past temperature and precipitation variations can help anticipate how these environments will respond to natural climate variability upon which human induced climate change is superimposed. Here we present a detailed multi-proxy analysis of a sediment core from Emerald Lake, located at the montane-subalpine forest transition in west-central Colorado. The record tracks changes in the lake environment, vegetation and fire activity mostly related to climate change for the latest Pleistocene and Holocene, and complements the previously published lake-level reconstruction from the same site. Vegetation and lake level show similar patterns with insolation changes and other regional paleoclimate records for temperature, with coldest conditions during the Younger Dryas (YD), warming in the early Holocene - thermal maximum reached around 6800 cal yr BP – and cooling in the middle and late Holocene. This record also shows how subalpine environments reacted to Holocene moisture dynamics for both summer, related to the North American Monsoon (NAM), and winter precipitation that could be associated with El Niño Southern Oscillation (ENSO), indicating that Emerald Lake was sensitive to long-term and millennial-scale regional and global climate changes. Climatic perturbations, generally cold and/or arid events and low lake levels at ca. 8200, 4200, 1200-1000 cal yr BP influenced the vegetation around Emerald Lake in association with well-known worldwide climatic events.

'Patterns and causes of marsupial paths in subalpine Tasmania

Animal paths can improve connectivity of species, alter vegetation growth, reduce fuel loads and further our knowledge of the behavioural ecology of mammals. Path patterning and the motivations for path creation are not well understood. The present study tested the hypotheses that animals form paths: (i) to efficiently move between palatable patches; (ii) for access to water; (iii) for access to shelter and (iv) to avoid predators. We used high-definition aerial online imagery to map paths in five treeless subalpine environments in Tasmania. Surveys of vegetation and scat counts were conducted at each site. We found that locality influenced wallaby scat density and that macropods and wombats created direct paths to move between areas of palatable vegetation, shelter and water. There was some weak indication of predator avoidance in some of the patterning. However, shelter from cold, strong southwesterly winds is a feasible alternative motivation for the patterns.

Gorilla beringei(Primates: Hominidae)

Gorilla beringeiMatschie, 1903 is a great ape commonly called the eastern gorilla. Highly sexually dimorphic, this diurnal knuckle-walking quadruped is 1 of 2 species of Gorilla, the largest living primates. It is endemic to northwest Rwanda and southwest Uganda as G. b. beringei, and to eastern Democratic Republic of the Congo as G. b. beringei and G. b. graueri. G. beringei is known to both highland and lowland montane forests and subalpine environments, though only G. b. beringei is called the “mountain gorilla.” Those inhabiting higher elevations are more folivorous than those at lower elevations. Groups are highly cohesive polygamous social units, varying in size and composition. G. b. beringei and G. b. graueri are both listed as “Critically Endangered” by the International Union for the Conservation of Nature and Natural Resources.Version of Record, first published online October 1, 2018, with fixed content and layout in compliance with Art. 8.1.3.2 ICZN