Environmental factors affecting the occurrence of periglacial landforms in Finnish Lapland : a numerical approach

Determination of the environmental factors controlling earth surface processes and landform patterns is one of the central themes in physical geography. However, the identification of the main drivers of the geomorphological phenomena is often challenging. Novel spatial analysis and modelling methods could provide new insights into the process-environment relationships. The objective of this research was to map and quantitatively analyse the occurrence of cryogenic phenomena in subarctic Finland. More precisely, utilising a grid-based approach the distribution and abundance of periglacial landforms were modelled to identify important landscape scale environmental factors. The study was performed using a comprehensive empirical data set of periglacial landforms from an area of 600 km2 at a 25-ha resolution. The utilised statistical methods were generalized linear modelling (GLM) and hierarchical partitioning (HP). GLMs were used to produce distribution and abundance models and HP to reveal independently the most likely causal variables. The GLM models were assessed utilising statistical evaluation measures, prediction maps, field observations and the results of HP analyses. A total of 40 different landform types and subtypes were identified. Topographical, soil property and vegetation variables were the primary correlates for the occurrence and cover of active periglacial landforms on the landscape scale. In the model evaluation, most of the GLMs were shown to be robust although the explanation power, prediction ability as well as the selected explanatory variables varied between the models. The great potential of the combination of a spatial grid system, terrain data and novel statistical techniques to map the occurrence of periglacial landforms was demonstrated in this study. GLM proved to be a useful modelling framework for testing the shapes of the response functions and significances of the environmental variables and the HP method helped to make better deductions of the important factors of earth surface processes. Hence, the numerical approach presented in this study can be a useful addition to the current range of techniques available to researchers to map and monitor different geographical phenomena.TAUSTAA Routailmiöiden ja niiden esiintymiseen vaikuttavien ympäristötekijöiden ymmärtäminen on tärkeää, koska yli 20 % maapallon maa-alasta on kylmissä ilmasto-oloissa vaikuttavien prosessien muokkaamaa aluetta, joka reagoi herkästi ympäristössä tapahtuviin muutoksiin. Laajojen ja harvaan asuttujen polaarialueiden kartoittaminen on kuitenkin kallista ja aikaa vievää työtä. Paikkatietojärjestelmät (GIS) ja tilastolliset menetelmät mahdollistavat kustannustehokkaan lähestymistavan erilaisten alueellisten ilmiöiden analysointiin. TUTKIMUKSEN TAVOITTEET Tässä tutkimuksessa mallinnettiin routailmiöiden esiintymistä paikkatietojärjestelmien ja tilastollisten menetelmien avulla 600 km2 alueelta Utsjoen Paistuntureilta. Keskeisimpinä tavoitteina oli tunnistaa routamuodostumien esiintymiseen vaikuttavat ympäristötekijät ja selvittää tilastollisten menetelmien, kuten yleistettyjen lineaaristen mallien ja hierarkisen ositusmenetelmän soveltuvuus routailmiötutkimuksiin. TULOKSET Pohjoisimmassa Suomessa metsänrajan yläpuolella esiintyy lukuisia erilaisia routaprosessien synnyttämiä muodostumia, joista useimmat ovat edelleen aktiivisia. Yleisimpiä muodostumaryhmiä ovat kuviomaat ja vuotomaat. Aktiivisten ilmiöiden esiintymisen kannalta keskeisimpiä maisematason ympäristötekijöitä ovat topografia, maaperä ja kasvillisuus. Etenkin korkeus merenpinnasta, rinteen kaltevuus, maaperän kosteus, turveala ja pensaspeittävyys korreloivat useimpien routailmiöiden kanssa. Tulosten arvioinnissa useimmat tilastolliset mallit osoittautuivat vakaiksi, ja niiden ennustuskyky vaihteli melko hyvästä erittäin hyvään. Parhaiten pystyttiin ennustamaan ikiroutaytimisten palsojen, erilaisten kuviomaiden ja vuotomaakilpien esiintymistä. JOHTOPÄÄTÖKSET Tämä tutkimus osoitti, että paikkatietojärjestelmiä ja tilastollisia menetelmiä voidaan tehokkaasti käyttää erilaisten routailmiöiden alueelliseen mallintamiseen. Numeerisilla menetelmillä voitiin selvittää ilmiöiden ja ympäristötekijöiden yhteyksiä, tunnistaa tärkeimmät itsenäisesti vaikuttavat tekijät ja ennustaa muodostumien levinneisyyttä subarktisessa tunturimaisemassa. Tässä tutkimuksessa käytettyä lähestymistapaa voidaan soveltaa myös muiden maantieteellisten ilmiöiden kartoitukseen ja alueellisten tutkimusongelmien ratkaisuun

The added value of geodiversity indices in explaining variation of stream macroinvertebrate diversity

Geodiversity, i.e. the variety of the abiotic environment, is considered to be positively correlated to biodiversity. In streams, the importance of physical heterogeneity for biodiversity variation is well known, but the usefulness of explicitly measured geodiversity indices to account for biodiversity has not been tested. We developed a technique to measure in-stream geodiversity, based on different types of stream flow, geomorphological processes and landforms observed from photographs taken during the field work, and substrates based on traditional field observations. We further tested the utility of these geodiversity measures in explaining variation in the biodiversity of macroinvertebrates in near-pristine streams. Our specific objective was to examine the explanatory power of geodiversity compared to traditional environmental variables, such as water chemistry, depth and current velocity. While most biodiversity indices correlated more strongly with traditional environmental variables, the influence of geodiversity on biodiversity was also evident. Unique effect of flow richness on species richness and that of total geodiversity on functional richness were higher than those of the traditional environmental variables. Our findings suggested that in-stream geodiversity offers a valuable concept for characterizing stream habitats. If further developed and tested, in-stream geodiversity can be used as a cost-efficient proxy to explain variation in biodiversity in stream environments.Peer reviewe

Impacts of permafrost degradation on infrastructure

The warming and thawing of ice-rich permafrost pose considerable threat to the integrity of polar and high-altitude infrastructure, in turn jeopardizing sustainable development. In this Review, we explore the extent and costs of observed and predicted infrastructure damage associated with permafrost degradation, and the methods available to mitigate such adverse consequences. Permafrost change imposes various threats to infrastructure, namely through warming, active layer thickening and thaw-related hazards such as thermokarst and mass wasting.These impacts, often linked to anthropogenic warming, are exacerbated through increased human activity. Observed infrastructure damage is substantial, with up to 80% of buildings in some Russian cities and -30% of some road surfaces in the Qinghai-Tibet Plateau reporting damage. Under anthropogenic warming, infrastructure damage is projected to continue, with 30-50% of critical circumpolar infrastructure thought to be at high risk by 2050. Accordingly, permafrost degradation-related infrastructure costs could rise to tens of billions of US dollars by the second half of the century. Several mitigation techniques exist to alleviate these impacts, including convection embankments, thermosyphons and piling foundations, with proven success at preserving and cooling permafrost and stabilizing infrastructure. To be effective, however, better understanding is needed on the regions at high risk.Peer reviewe

The role of landscape, topography, and geodiversity in explaining vascular plant species richness in a fragmented landscape

We explained vascular plant species richness patterns in a 286 km2 fragmented landscape with a notable human influence. The objective of this study was two-fold: to test the relative importance of landscape, topography and geodiversity measures, and to compare three different landscape-type variables in species richness modeling. Moreover, we tested if results differ when only native species are considered. We used generalized linear modeling based variation partitioning and generalized additive models with different explanatory variable sets. Landscape and topography explained the majority of the variation but the relative importance of topography and geodiversity was higher in explaining native species richness than in explaining total species richness. Differences between the three landscape type variables were small and they provided complementary information. Finally, topography and geodiversity often direct human action and can be ultimate causes behind both landscape variability and species richness patterns.peerReviewe

Different species trait groups of stream diatoms show divergent responses to spatial and environmental factors in a subarctic drainage basin

Understanding the drivers of community structure is an important topic in ecology. We examined whether different species trait groups of stream diatoms (ecological guilds and specialization groups) show divergent responses to spatial and environmental factors in a subarctic drainage basin. We used local- and catchment-scale environmental and spatial variables in redundancy analysis and variation partitioning to examine community structuring. Local and catchment conditions and spatial variables affected diatom community structure with different relative importance. Local-scale environmental variables explained most of the variation in the low-profile and motile guilds, whereas local and spatial variables explained the same amount of the variation in the high-profile guild. The variations in the planktic guild and the specialist species were best explained by spatial variables, and catchment variables explained most variation only in generalist species. Our study showed that diatom communities in subarctic streams are a result of both environmental filtering and spatial processes. Our findings also suggested that dividing whole community into different groups by species traits can increase understanding of metacommunity organization.Peer reviewe

Different species trait groups of stream diatoms show divergent responses to spatial and environmental factors in a subarctic drainage basin

Understanding the drivers of community structure is an important topic in ecology. We examined whether different species trait groups of stream diatoms (ecological guilds and specialization groups) show divergent responses to spatial and environmental factors in a subarctic drainage basin. We used local- and catchment-scale environmental and spatial variables in redundancy analysis and variation partitioning to examine community structuring. Local and catchment conditions and spatial variables affected diatom community structure with different relative importance. Local-scale environmental variables explained most of the variation in the low-profile and motile guilds, whereas local and spatial variables explained the same amount of the variation in the high-profile guild. The variations in the planktic guild and the specialist species were best explained by spatial variables, and catchment variables explained most variation only in generalist species. Our study showed that diatom communities in subarctic streams are a result of both environmental filtering and spatial processes. Our findings also suggested that dividing whole community into different groups by species traits can increase understanding of metacommunity organization.Peer reviewe

Extensible Architectures: The Strategic Value of Service Oriented Architecture in Banking

Information and communication technology (ICT) has helped to drive increasingly intense global competition. In turn, this intensity increases the need for flexibility and rapid changeability in ICT to support strategies that depend on organizational agility. We report a comparative, cross-cultural case study of the implementation of Service Oriented Architectures (SOA) at a Scandinavian bank and a Swiss bank. The strategic rewards in the adoption of SOA appear to go beyond marketplace issues of ICT capability acquisition, and unexpectedly arise in the creation of an extensible organizational ICT architecture. The extensibility of the ICT architecture that results from the adoption of SOA provides potential for greater organizational agility (and thereby competitiveness)

A methodological guide to observe local-scale geodiversity for biodiversity research and management

Current global environmental change calls for comprehensive and complementing approaches for biodiversity conservation. According to recent research, consideration of the diversity of Earth's abiotic features (i.e. geodiversity) could provide new insights and applications into the investigation and management of biodiversity. However, methods to map and quantify geodiversity at local scale have not been developed although this scale is important for conservation planning. Here, we introduce a field methodology for observing plot-scale geodiversity, pilot the method in an Arctic–alpine tundra environment, provide empirical evidence on the plot-scale biodiversity–geodiversity relationship and give guidance for practitioners on the implementation of the method. The field method is based on observation of geofeatures, that is, elements of geology, geomorphology and hydrology, from a given area surrounding a location of species observations. As a result, the method provides novel information on the variation of abiotic nature for biodiversity research and management. The method was piloted in northern Norway and Finland by observing geofeatures from 76 sites at three scales (5, 10 and 25 m radii). To explore the relationship between measures of biodiversity and geodiversity, the occurrence of vascular plant species was recorded from 2 m × 2 m plots at the same sites. According to the results, vascular plant species richness was positively correlated with the richness of geofeatures (Rs = 0.18–0.59). The connection was strongest in habitats characterized by deciduous shrubs. The method has a high potential for observing geofeatures without extensive geological or geomorphological training or field survey experience and could be applied by conservation practitioners. Synthesis and applications. Consideration of geodiversity in understanding, analysing and conserving biodiversity could facilitate environmental management and ensure the long-term sustainability of ecosystem functions. With the developed method, it is possible to cost-efficiently observe the elements of geodiversity that are useful in ecology and biodiversity conservation. Our approach can be adapted in different ecosystems and biodiversity investigations. The method can be adjusted depending on the abiotic conditions, expertise of the observer(s) and the equipment available.publishedVersio

Correlates of different facets and components of betadiversity in stream organisms

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