Temperate Mountainous Regions Research Articles

Same, but different: similar states of forest structure in temperate mountain regions of Europe despite different social-ecological forest disturbance regimes

ContextEcosystem services provided by mountain forests are critically linked to forest structure. Social-ecological disturbance regimes (i.e., the rate, frequency, and patch size distribution of disturbances driven by interacting natural and anthropogenic processes) and land use affect forest structure, but their specific impacts are not fully understood.ObjectivesWe examine how differences in disturbance regimes affect patterns of forest structure across three European mountain ranges with similar vegetation types but different land-use histories: the European Alps, the Carpathians, and the Caucasus.MethodsWe related data on horizontal and vertical forest structure, measured by spaceborne lidar (GEDI), with Landsat-derived information on forest disturbances (1986–2020) and topographic, climatic, and anthropogenic predictors.ResultsWe found similar social-ecological disturbance regimes in the Alps and Carpathians (average annual disturbance rates of 0.34% and 0.39%, respectively, and median patch size < 0.5 ha), yet much lower disturbance rates and patch sizes in the Caucasus (0.08% yr−1 and < 0.2 ha). Despite different disturbance regimes, we found similar patterns of forest structure. Two alternative states emerged consistently across all mountain ranges: a tall and closed-canopy state in 74–80% of forests and a low and open-canopy state (< 50% canopy cover) in the rest. While forest structure responded consistently to abiotic drivers such as topography and climate, its association with anthropogenic pressures differed between mountain ranges. Stand-replacing disturbances played an important role in the Carpathians, while forest structure in the Caucasus was related to proximity to settlements, reflecting local forest use.ConclusionsDifferent social-ecological contexts in mountain regions can produce markedly different forest disturbance regimes. Despite these differences, similar states of forest structures emerge, suggesting strong attractors of structure in temperate mountain forests.

Positive and negative plant−plant interactions influence seedling establishment at both high and low elevations

Deciphering how plants interact with each other across environmental gradients is important to understand plant community assembly, as well as potential future plant responses to environmental change. Plant−plant interactions are expected to shift from predominantly negative (i.e. competition) to predominantly positive (i.e. facilitation) along gradients of environmental severity. However, most experiments examine the net effects of interactions by growing plants in either the presence or absence of neighbours, thereby neglecting the interplay of both negative and positive effects acting simultaneously within communities. To partially unravel these effects, we tested how the seedling establishment of 10 mountain grassland plants varied in the presence versus absence of plant communities at two sites along an elevation gradient. We created a third experimental treatment (using plastic plant mats to mimic surrounding vegetation) that retained the main hypothesised benefits of plant neighbours (microsite amelioration), while reducing a key negative effect (competition for soil resources). In contrast to our expectations, we found evidence for net positive effects of vegetation at the low elevation site, and net negative effects at the high elevation site. Interestingly, the negative effects of plant neighbours at high elevation were driven by high establishment rates of low elevation grasses in bare soil plots. At both sites, establishment rates were highest in artificial vegetation (after excluding two low elevation grasses at the high elevation site), indicating that positive effects of above-ground vegetation are partially offset by their negative effects. Our results demonstrate that both competition and facilitation act jointly to affect community structure across environmental gradients, while emphasising that competition can be strong also at higher elevations in temperate mountain regions. Consequently, plant−plant interactions are likely to influence the establishment of new, and persistence of resident, species in mountain plant communities as environments change.

A glacier in transition: Surface elevation change, ELA and geomorphic evolution of a very small glacier in the Dolomites (S-E Alps)

Small glaciers of temperate mountain regions are suffering significant reduction, with ice mass losses reaching unprecedented melt rates in the very last years. On the other hand, several glacial bodies experienced increasing debris inputs since the end of the Little Ice Age, transitioning from rather clean ice to debris-covered and, sometimes, to rock glaciers. Here we present the recent surface elevation change (2006–2022) of the Popera Alto glacier, a very small debris-covered glacier in the Sesto Dolomites (S-E European Alps), retrieved from a combination of airborne LiDAR and Structure from Motion surveys. We analyse the glacier evolution in terms of surface cover and geomorphic processes, reconstructing its palaeo-volume and -extent from geomorphological evidence. The environmental Equilibrium Line Altitude (envELA) based on climatic data is compared to the effective ELA (effELA), discussing the role of local topography in the evolution of small debris-covered glaciers. Popera Alto glacier lost 0.35 m w.e. yr−1 in the last 16 years, with its surface cover actively modified by geomorphic processes. Debris and local topography feedback allowed the resilience of the glacier, with marked difference between the current envELA of the area, 3480 m a.s.l., and the effELA of the glacier, 2550 m a.s.l. As such, Popera Alto glacier shows evidence of transitioning from a glacial to a periglacial landform.

Smaller, more diverse and on the way to the top: Rapid community shifts of montane wild bees within an extraordinary hot decade

AbstractAimGlobal warming is assumed to restructure mountain insect communities in space and time. Theory and observations along climate gradients predict that insect abundance and richness, especially of small‐bodied species, will increase with increasing temperature. However, the specific responses of single species to rising temperatures, such as spatial range shifts, also alter communities, calling for intensive monitoring of real‐world communities over time.LocationGerman Alps and pre‐alpine forests in south‐east Germany.MethodsWe empirically examined the temporal and spatial change in wild bee communities and its drivers along two largely well‐protected elevational gradients (alpine grassland vs. pre‐alpine forest), each sampled twice within the last decade.ResultsWe detected clear abundance‐based upward shifts in bee communities, particularly in cold‐adapted bumble bee species, demonstrating the speed with which mobile organisms can respond to climatic changes. Mean annual temperature was identified as the main driver of species richness in both regions. Accordingly, and in large overlap with expectations under climate warming, we detected an increase in bee richness and abundance, and an increase in small‐bodied species in low‐ and mid‐elevations along the grassland gradient. Community responses in the pre‐alpine forest gradient were only partly consistent with community responses in alpine grasslands.Main ConclusionIn well‐protected temperate mountain regions, small‐bodied bees may initially profit from warming temperatures, by getting more abundant and diverse. Less severe warming, and differences in habitat openness along the forested gradient, however, might moderate species responses. Our study further highlights the utility of standardized abundance data for revealing rapid changes in bee communities over only one decade.

The species range-size patterns for vascular plants of Seorak Mountain (Korea): Relationship between group of life forms and phytogeography affinity along the elevational gradient.

Research on species richness patterns and the advanced elevational Rapoport rule (ERR) has been widespread in recent years; however, there is a lack of such research for the temperate mountainous regions in northeast Asia. Here, we collected plant species from the Seorak Mountain in northeast Asia through field surveys. The species were divided into 11 groups according to the life‐form types and phytogeography affinities of each species. The ERR was evaluated using Steven's method and by examining the species richness patterns of each group. The species richness patterns revealed a positive multimodal pattern along the elevation gradient, but phytogeography affinities (increasing trend) and life‐form analysis (unimodal) exhibited different patterns. The elevation gradients (1,350 m for the mean elevation–range relationships), which are affected by the boundary effect and different life forms, did not consistently support the ERR. However, herbs as well as rare, endemic, and red list species showed consistent support for the ERR, which could be attributed to the influence by phytogeography affinities. Therefore, the results from Seorak Mountain showed that the ERR was not consistent for different plant life forms in the same area; however, phytogeography affinities could support and explain ERR.

Winter Climate and Lake Morphology Control Ice Phenology and Under‐Ice Temperature and Oxygen Regimes in Mountain Lakes

AbstractWarming winters will reduce ice cover and change under‐ice conditions in temperate mountain lakes, where snow contributes most of winter cover on lakes. Snow‐dominated mountain lakes are abundant and highly susceptible to climate warming, yet we lack an understanding of how climate variation and local attributes influence winter processes. We investigated climatic and intrinsic controls on ice phenology, water temperature, and bottom‐water dissolved oxygen (DO) in 15 morphologically diverse lakes in the Sierra Nevada and Klamath Mountains of California, USA, using high‐frequency measurements from multiple (2–5) winters. We found that ice phenology was determined by winter climate variables (snowfall and air temperature) that influence ice‐off timing, whereas ice‐on timing was relatively invariant among years. Lake size and morphology mediated the effect of climate on lake temperature and DO dynamics in early and late winter. Rates of hypolimnetic DO decline were highest in small, shallow lakes, and were unrelated to water temperature. Temperature and oxygen dynamics were more variable in small lakes because heavy snowfall caused ice submergence, mixing, and DO replenishment that affected the entire water column. As the persistence of snow declines in temperate mountain regions, autumn, and spring climatic conditions are expected to gain importance in regulating lake ice phenology. Water temperature and DO will likely increase in most lakes during winter as snowpack declines, but morphological attributes such as lake size will determine the sensitivity of ice phenology and under‐ice processes to climate change.

17-Year-Long Sewage Sludge Ash Concrete Exposure Test

This study was conducted on concrete using sewage sludge ash (SSA) with the aim to establish an efficient use of SSA as a cement replacement material. Concrete specimens with three degrees of strength were made from two different SSAs and exposed in temperate plain and cold mountain regions for a prolonged period of time to investigate the long-term properties of SSA concrete. After 17 years of exposure, the properties of the specimens were examined. SSA concrete basically maintained its strength after 17 years of exposure. No significant drop in the relative dynamic modulus of elasticity was detected in SSA concrete left in a cold mountain region, despite the fact that it would be exposed to a considerable number of freeze-and-thaw cycles. It was also confirmed that the SSA concrete exhibited high resistance against carbonation. A small amount of Katoite formed in the hardened cement/SSA mixture, probably due to the high content of Al2O3 in SSA. No abnormal formation of ettringite was observed.

Evidence of genetic determination in the growth habit of Nothofagus pumilio (Poepp. & Endl.) Krasser at the extremes of an elevation gradient

ABSTRACT In temperate mountainous regions, altitudinal clines in tree size and growth habit develop from a gradual adjustment of multiple traits to tolerate harshening conditions with altitude. We perform a common garden trial with seedlings from two stands of Nothofagus pumilio: low altitude, tall forest (1200 m a.s.l) vs. high altitude, shrubby forest (1560 m a.s.l), to determine whether the contrasting growth habits observed in the forest have a genetic basis, which expresses in the juvenile tree life stage. Growth habit syndrome was assessed including size, phenology, growth rhythm and architecture traits. Shrubby archetypes, i.e. small densely-branched plants with codominant axes, were more frequent between plants from higher altitude. Instead, large single-stemmed, slender morphotypes prevailed between plants from the lower stand. These contrasting frequencies between both extremes of the elevation gradient could be explained by differences in cumulative effects in multiple underlying traits, giving clues that there could be genetic determination in the growth habit of N. pumilio. Based on our findings, we recommend that the sampling strategy of future study systems of N. pumilio genetic variation, should encompass multiple elevation gradients along its distribution. Meanwhile, altitudinal zoning seems a precautionary advice for ongoing restoration plans.

Locomotor activity patterns of takin (Budorcas taxicolor) in a temperate mountain region

Understanding locomotor activity patterns would reveal key information about an animal's foraging strategy, energy budget and evolutionary adaptation. We studied the locomotor activity patterns of the takin (Budorcas taxicolor) in a temperate mountain region in China using GPS radio-collar technology from 1 July 2014 to 30 June 2015. Our research showed that takin had a bimodal crepuscular locomotor activity pattern, with an especially obvious movement peak at dusk. The takins showed significant seasonal differences in their movement rates, with the lowest movement rate in winter. The animals also showed sexual differences in their movement rates. In spring, the female movement rate was significantly higher than that of males during daytime, while during nighttime the movement rate of males was higher than that of females. The male movement rate was significantly higher than that of females in summer. The movement rate of the takins were correlated to microenvironment temperature and normalized difference vegetation index (NDVI) in each season. These findings suggest that takin could adjust locomotor activity levels adapt to reproductive requirements, temperature variation and forage variability.

Phylogenetic signal in the topographic niche of trees: Current and historical significance of habitat structure on the species arrangement pattern within East Asian rugged forests

AbstractTopography often promotes habitat heterogeneity and is a major factor in fine‐grained changes in vegetation. Especially in temperate mountainous regions of East Asia, the distribution of tree species is largely explained by topographic niche differentiation. Because species niche is at least partially a historical product through the evolution of functional traits, phylogenetic signals are expected in the topographic arrangement pattern of species, although this has not been fully investigated. Thus, we examined common temperate trees in a 306 ha watershed on Mt Tanzawa, central Japan. The topographic niche position of each species was explained with two principal component analysis (PCA) axes, which aligned with the topographic structure of the watershed. High scores on PC1 reflected lower elevations, steeper slopes and nearby valleys. Higher scores on PC2 indicated thicker soil, more south‐facing slopes, slighter slope inclinations and nearby valleys. The former indicated the species were aligned on a habitat gradient of land‐surface instability, for which the gradient is typical under the current geological conditions. The latter indicated that a niche axis for resource availability relating to water, nutrients and light or heat existed. A phylogenetic signal, identified by Pagel's λ and the Mantel test, was detected for PC2 scores. However, the species arrangement along PC1 was independent of phylogeny. Our results suggested that the topographic niche of tree species in this area is caused by both relatively recently derived traits regarding adaptation to unstable land surfaces and conservative traits derived through plant evolution.

What are the most crucial soil variables for predicting the distribution of mountain plant species? A comprehensive study in the Swiss Alps

AbstractAimTo investigate the potential of a large range of soil variables to improve topo‐climatic models of plant species distributions in a temperate mountain region encompassing complex relief.LocationThe western Swiss Alps.MethodsFitting topo‐climatic models for &gt;60 plant species across &gt;250 sites with and without added soil predictor variables (&gt;30). Testing included the following: (a) which soil variables improve plant species distribution models; (b) whether an optimal subset of soil variables can improve models for the majority of species and habitat types and (c) how much variation in plant species distributions soil variables alone explain.ResultsGeochemical variables (i.e. CaO, pH and inorganic carbon) and a drainage indicator (i.e. bulk soil water content) improved the predictive abilities of the models across the large majority of alpine plant species. The improvement of the models after the addition of soil information varied strongly between plant species and habitat types, but a trade‐off was found between the number of soil variables and the associated gain in model performance. Finally, across all species, one specific combination of soil variables – bulk soil water content + total phosphorus +δ13C – outperformed the commonly used topo‐climatic variables.Main conclusionsSeveral soil variables significantly increased the predictive power of plant species distribution models in the temperate mountain region. Geochemical and drainage variables proved most important.

Floodplain downed wood volumes: a comparison across three biomes

AbstractDowned large wood (LW) in floodplains provides habitat and nutrients for diverse organisms, influences hydraulics and sedimentation during overbank flows, and affects channel form and lateral migration. Very few studies, however, have quantified LW volumes in floodplains that are unaltered by human disturbance. We compare LW volumes in relatively unaltered floodplains of semiarid boreal lowland, subtropical lowland, and semiarid temperate mountain rivers in the United States. Average volumes of downed LW are 42.3 m3 ha−1, 50.4 m3 ha−1, and 116.3 m3 ha−1 in the semiarid boreal, subtropical, and semiarid temperate sites, respectively. Observed patterns support the hypothesis that the largest downed LW volumes occur in the semiarid temperate mountain sites, which is likely linked to a combination of moderate‐to‐high net primary productivity, temperature‐limited decomposition rates, and resulting slow wood turnover time. Floodplain LW volumes differ among vegetation types within the semiarid boreal and semiarid temperate mountain regions, reflecting differences in species composition. Lateral channel migration and flooding influence vegetation communities in the semiarid boreal sites, which in turn influences floodplain LW loads. Other forms of disturbance such as fires, insect infestations, and blowdowns can increase LW volumes in the semiarid boreal and semiarid temperate mountain sites, where rates of wood decay are relatively slow compared with the subtropical lowland sites. Although sediment is the largest floodplain carbon reservoir, floodplain LW stores substantial amounts of organic carbon and can influence floodplain sediment storage. In our study sites, floodplain LW volumes are lower than those in adjacent channels, but are higher than those in upland (i.e. non‐floodplain) forests. Given the important ecological and physical effects of floodplain LW, efforts to add LW to river corridors as part of restoration activities, and the need to quantify carbon stocks within river corridors, we urge others to quantify floodplain and instream LW volumes in diverse environments. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Burn me twice, shame on who? Interactions between successive forest fires across a temperate mountain region.

Increasing rates of natural disturbances under a warming climate raise important questions about how multiple disturbances interact. Escalating wildfire activity in recent decades has resulted in some forests re-burning in short succession, but how the severity of one wildfire affects that of a subsequent wildfire is not fully understood. We used a field-validated, satellite-derived, burn-severity atlas to assess interactions between successive wildfires across the US Northern Rocky Mountains a 300,000-km2 region dominated by fire-prone forests. In areas that experienced two wildfires between 1984 and 2010, we asked: (1) How do overall frequency distributions of burn-severity classes compare between first and second fires? (2) In a given location, how does burn severity of the second fire relate to that of the first? (3) Do interactions between successive fires vary by forest zone or the interval between fires? (4) What factors increase the probability of burning twice as stand-replacing fire? Within the study area, 138,061ha burned twice between 1984 and 2010. Overall, frequency distributions of burn severity classes (low, moderate, high; quantified using relativized remote sensing indices) were similar between the first and second fires; however burn severity was 5-13% lower in second fires on average. Negative interactions between fires were most pronounced in lower-elevation forests and woodlands, when fire intervals were <10yr, and when burn severity was low in the first fire. When the first fire burned as high severity and fire intervals exceeded 10-12yr, burn-severity interactions switched from negative to positive, with high-severity fire begetting subsequent high-severity fire. Locations most likely to experience successive stand-replacing fires were high-elevation forests, which are adapted to high-severity fire, and areas conducive to abundant post-fire tree regeneration. Broadly similar severities among short-interval "re-burns" and other wildfires indicate that positive severity feedbacks, an oft-posited agent of ecosystem decline or state shift, are not an inevitable outcome of re-burning. Nonetheless, context-dependent shifts in both the magnitude and direction of wildfire interactions (associated with forest zone, initial burn-severity, and disturbance interval) illustrate complexities in disturbance interactions and can inform management and predictions of future system dynamics.

Seasonal variation of freezing resistance mechanisms in north-temperate alpine plants

Alpine herbaceous plants employ two mechanisms to prevent freezing injury to leaves during the growing season, i.e., they avoid freezing by transient supercooling or tolerate the occurrence of extracellular ice. I examined seasonal changes in the two freezing resistance mechanisms in leaves of alpine plants from two temperate mountain regions, Niwot Ridge (3500 m) in the Front Range of the Rocky Mts. (USA) and Modre sedlo (1510 m) in the Giant Mts. (Czech Republic). Although plants from Niwot Ridge were on average ca. 2.6 K more resistant to freezing than plants from the Giant Mts., patterns of freezing resistance changes during the growing season were consistent between the two regions. Both freezing resistance mechanisms, i.e., avoidance by supercooling and tolerance of extracellular ice were encountered. Plants predominantly avoided freezing injury during early summer and tolerated extracellular freezing at the end of the growing season, and the seasonal change from avoidance to tolerance mechanisms was significant for both regions. The avoidance and tolerance mechanisms provided comparable freezing resistance to the plants during early summer but, unlike in avoidant plants, in tolerant plants resistance increased over the course of the season. The species formed three groups with regard to resistance mechanisms employed during the season: (1) species that avoided injury by supercooling during early summer and employed freezing tolerance towards autumn; (2) species that were freezing tolerant during the entire growing season; and (3) species with ephemeral shoots that solely avoided freezing by supercooling. Although freezing tolerance is a common feature in north-temperate alpine plants, avoidance by supercooling as a freezing resistance strategy might be selected for in species with particular life histories such as ephemeral hemiparasites.

On the Importance of High-Resolution Time Series of Optical Imagery for Quantifying the Effects of Snow Cover Duration on Alpine Plant Habitat

We investigated snow cover dynamics using time series of moderate (MODIS) to high (SPOT-4/5, Landsat-8) spatial resolution satellite imagery in a 3700 km2 region of the southwestern French Alps. Our study was carried out in the context of the SPOT (Take 5) Experiment initiated by the Centre National d’Etudes Spatiales (CNES), with the aim of exploring the utility of high spatial and temporal resolution multispectral satellite imagery for snow cover mapping and applications in alpine ecology. Our three objectives were: (i) to validate remote sensing observations of first snow free day derived from the Normalized Difference Snow Index (NDSI) relative to ground-based measurements; (ii) to generate regional-scale maps of first snow free day and peak standing biomass derived from the Normalized Difference Vegetation Index (NDVI); and (iii) to examine the usefulness of these maps for habitat mapping of herbaceous vegetation communities above the tree line. Imagery showed strong agreement with ground-based measurements of snow melt-out date, although R2 was higher for SPOT and Landsat time series (0.92) than for MODIS (0.79). Uncertainty surrounding estimates of first snow free day was lower in the case of MODIS, however (±3 days as compared to ±9 days for SPOT and Landsat), emphasizing the importance of high temporal as well as high spatial resolution for capturing local differences in snow cover duration. The main floristic differences between plant communities were clearly visible in a two-dimensional habitat template defined by the first snow free day and NDVI at peak standing biomass, and these differences were accentuated when axes were derived from high spatial resolution imagery. Our work demonstrates the enhanced potential of high spatial and temporal resolution multispectral imagery for quantifying snow cover duration and plant phenology in temperate mountain regions, and opens new avenues to examine to what extent plant community diversity and functioning are controlled by snow cover duration.

Carbon storage versus albedo change: radiative forcing of forest expansion in temperate mountainous regions of Switzerland

Abstract. In this study, we assess the climate mitigation potential from afforestation in a mountainous snow-rich region (Switzerland) with strongly varying environmental conditions. Using radiative forcing calculations, we quantify both the carbon sequestration potential and the effect of albedo change at high resolution. We calculate the albedo radiative forcing based on remotely sensed data sets of albedo, global radiation and snow cover. Carbon sequestration is estimated from changes in carbon stocks based on national inventories. We first estimate the spatial pattern of radiative forcing (RF) across Switzerland assuming homogeneous transitions from open land to forest. This highlights where forest expansion still exhibits climatic benefits when including the radiative forcing of albedo change. Second, given that forest expansion is currently the dominant land-use change process in the Swiss Alps, we calculate the radiative forcing that occurred between 1985 and 1997. Our results show that the net RF of forest expansion ranges from −24 W m−2 at low elevations of the northern Prealps to 2 W m−2 at high elevations of the Central Alps. The albedo RF increases with increasing altitude, which offsets the CO2 RF at high elevations with long snow-covered periods, high global radiation and low carbon sequestration. Albedo RF is particularly relevant during transitions from open land to open forest but not in later stages of forest development. Between 1985 and 1997, when overall forest expansion in Switzerland was approximately 4%, the albedo RF offset the CO2 RF by an average of 40%. We conclude that the albedo RF should be considered at an appropriately high resolution when estimating the climatic effect of forestation in temperate mountainous regions.

Snow surface energy and mass balance in a warm temperate climate mountain

Summary In warm temperate mountain regions where water is often scarce vapor losses from the snow-surface can substantially limit snowmelt. Therefore, understanding the key snow dynamic processes that affect water availability in these mountains is essential. We studied the snowpack energy and mass balance in Mt. Hermon, Israel using a comprehensive field campaign during 2010/11. We analyzed the snowpack energy and mass balance during the winter of 2010/11 in a Deep Snow Patch (DSP), and in the Bulan valley experiment area (BVEA), where both windswept locations and lee-side (deep snowpack) locations were examined. We applied for this analysis an energy and mass balance snow model that was forced by input from two meteorological stations. The calibration of the model for the DSP and BVEA was based on surveyed snow water equivalent data, and melting cycles that were measured with time-lapse cameras, respectively. Using a step function to describe wind speed over the DSP we showed that the turbulent fluxes were influenced by changes in snowpack height. The turbulent fluxes were found as the dominant energy fluxes at the snow-surface. During winter, vapor losses varied between 46% and 82% of the total ablation. Consequently, latent heat flux consumed much of the available energy at the snow-surface, greatly limiting melting rate to 1 mm day−1. During spring, vapor flux was positive which enhanced condensation, resulting in an average melting flux of 86 mm day−1. The spatial variation in the vapor flux at the BVEA due to terrain orientation yield variation in space of the available water at the bottom of the snowpack.

A world-wide perspective on crucifer speciation and evolution: phylogenetics, biogeography and trait evolution in tribe Arabideae.

Tribe Arabideae are the most species-rich monophyletic lineage in Brassicaceae. More than 500 species are distributed in the majority of mountain and alpine regions worldwide. This study provides the first comprehensive phylogenetic analysis for the species assemblage and tests for association of trait and characters, providing the first explanations for the enormous species radiation since the mid Miocene. Phylogenetic analyses of DNA sequence variation of nuclear encoded loci and plastid DNA are used to unravel a reliable phylogenetic tree. Trait and ancestral area reconstructions were performed and lineage-specific diversification rates were calculated to explain various radiations in the last 15 Myr in space and time. A well-resolved phylogenetic tree demonstrates the paraphyly of the genus Arabis and a new systematic concept is established. Initially, multiple radiations involved a split between lowland annuals and mountain/alpine perennial sister species. Subsequently, increased speciation rates occur in the perennial lineages. The centre of origin of tribe Arabideae is most likely the Irano-Turanian region from which the various clades colonized the temperate mountain and alpine regions of the world. Mid Miocene early diversification started with increased speciation rates due to the emergence of various annual lineages. Subsequent radiations were mostly driven by diversification within perennial species during the Pliocene, but increased speciation rates also occurred during that epoch. Taxonomic concepts in Arabis are still in need of a major taxonomic revision to define monophyletic groups.

Predicting climate-change-caused changes in global temperature on potato tuber moth Phthorimaea operculella (Zeller) distribution and abundance using phenology modeling and GIS mapping

Originating from the Andean region and co-evolved with its food plant, the potato (Solanum sp.), the potato tuber moth Phthorimaea operculella (Zeller) has become an invasive potato pest globally. The hypothesis of our present study was that the future distribution and abundance (damage potential) of this pest will be greatly affected by climate-change-caused changes in temperature. We used a process-based climatic phenology model for P. operculella and applied three risk indices (establishment-, generation, and activity index) in a geographic information system (GIS) environment to map and quantify changes for climate change scenarios of the year 2050 based on downscaled climate-change data of the scenario A1B from the WorldClim database. All applications and simulations were made using the Insect Life Cycle Modeling (ILCYM) software recently developed by The International Potato Center, Lima, Peru. The study concludes that there are three possible main scenarios of changes that may simultaneously occur: (1) the P. operculella damage potential will progressively increase in all regions where the pest already prevails today with an excessive increase in warmer cropping regions of the tropics and subtropics. In regions where P. operculella is established and develops >4 generations per year, economic losses are likely to occur; under the current climate, >4 generations are developed on 30.1% of the total potato production area worldwide, which will increase until the year 2050 to 42.4%, equal to an increase of 2,409,974ha of potato under new infestation. (2) A range expansion in temperate regions of the northern hemisphere with additionally 8.6% (699,680ha), 4.2% (32,873ha), and 2.7% (234,404ha) of the potato production area under higher risk in Asia, North America, and Europe, with moderate increases of its damage potential. (3) A range expansion in tropical temperate mountainous regions with a moderate increase of its damage potential; e.g., in Bolivia, Ecuador and Peru 44,281ha, 9569ha, and 39,646ha of potato will be under new risk of infestation. The ILCYM software allowed a detailed analysis of possible climate-change-induced changes in temperature on P. operculella distribution and damage potential. Further, this tool offers means of overcoming limitations in predictions and mapping experienced with climate data interpolation and resolution by spatial point-by-point simulations at locations of interest. The methodology is proposed as a very helpful tool for adaptation planning in integrated pest management.

Twenty Years After the 1988 Yellowstone Fires: Lessons About Disturbance and Ecosystems

The 1988 Yellowstone fires were among the first in what has proven to be an upsurge in large severe fires in the western USA during the past 20 years. At the time of the fires, little was known about the impacts of such a large severe disturbance because scientists had had few previous opportunities to study such an event. Ecologists predicted short- and long-term effects of the 1988 fires on vegetation, biogeochemistry, primary productivity, wildlife, and aquatic ecosystems based on scientific understanding of the time. Twenty-plus years of subsequent study allow these early predictions to be evaluated. Most of the original predictions were at least partially supported, but some predictions were refuted, others nuanced, and a few postfire phenomena were entirely unexpected. Post-1988 Yellowstone studies catalyzed advances in ecology focused on the importance of spatial and temporal heterogeneity, contingent influences, and multiple interacting drivers. Post-1988 research in Yellowstone also has changed public perceptions of fire as an ecological process and attitudes towards fire management. Looking ahead to projected climate change and more frequent large fires, the well-documented ecological responses to the 1988 Yellowstone fires provide a foundation for detecting and evaluating potential changes in fire regimes of temperate mountainous regions.