A5059058925- Plant Water Relations and Carbon Dynamics
- Tree-ring climate responses
- Plant responses to elevated CO2
- Climate change and permafrost
- Cryospheric studies and observations
- Forest ecology and management
- Ecology and Vegetation Dynamics Studies
- Geology and Paleoclimatology Research
- Fire effects on ecosystems
- Isotope Analysis in Ecology
- Species Distribution and Climate Change
- Lichen and fungal ecology
- Soil Carbon and Nitrogen Dynamics
- Mycorrhizal Fungi and Plant Interactions
- Peatlands and Wetlands Ecology
- Air Quality and Health Impacts
- Insect behavior and control techniques
- Botany and Plant Ecology Studies
- Atmospheric chemistry and aerosols
- Pleistocene-Era Hominins and Archaeology
- Plant and animal studies
- Hydrology and Watershed Management Studies
- Insurance, Mortality, Demography, Risk Management
- Tree Root and Stability Studies
- Landslides and related hazards
Swiss Federal Institute for Forest, Snow and Landscape Research
2010-2020
University of Basel
2010-2011
Tuskegee University
1987
The rapidly warming temperatures in high-latitude and alpine regions have the potential to alter phenology of Arctic plants, affecting processes ranging from food webs ecosystem trace gas fluxes. International Tundra Experiment (ITEX) was initiated 1990 evaluate effects expected rapid changes temperature on tundra plant phenology, growth community using experimental warming. Here, we used ITEX control data test phenological responses background variation across sites spanning latitudinal...
Climate warming may alter ecosystem nitrogen (N) cycling by accelerating N transformations in the soil, and changes be especially pronounced cold regions characterized N-poor ecosystems. We investigated dynamics across plant-soil continuum during 6 years of experimental soil (2007-2012; +4 °C) at a Swiss high-elevation treeline site (Stillberg, Davos; 2180 m a.s.l.) featuring Larix decidua Pinus uncinata. In we observed considerable increases NH4+ pool size first (by >50%), but this effect...
Understanding the interplay between environmental factors contributing to treeline formation and how these influence different life stages remains a major research challenge. We used an afforestation experiment including 92 000 trees investigate spatial temporal dynamics of tree mortality growth at in Swiss Alps. Seedlings three high‐elevation conifer species ( Larix decidua , Pinus mugo ssp. uncinata cembra ) were systematically planted along altitudinal gradient above current (2075 2230 m...
Climate change and elevated atmospheric CO 2 levels could increase the vulnerability of plants to freezing. We analyzed tissue damage resulting from naturally occurring freezing events in a long–term situ enrichment (+ 200 ppm, 2001–2009) soil warming 4°C since 2007) experiment at treeline Swiss Alps (Stillberg, Davos). Summer caused several abundant subalpine alpine plant species four out six years between 2005 2010. Most occurred when temperatures dropped below –1.5°C two three weeks after...
Summary 1. Using experimental atmospheric CO 2 enrichment, we tested for tree growth stimulation at the high‐elevation treeline, where there is overwhelming evidence that low temperature inhibits despite an adequate carbon supply. We exposed Larix decidua (European larch) and Pinus mugo ssp. uncinata (mountain pine) to 9 years of free‐air enrichment (FACE) in situ experiment treeline Swiss Alps (2180 m a.s.l.). 2. Accounting pre‐treatment vigour individual trees, ring increments throughout...
Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss investigate changes in vegetation biomass after 9 years free air enrichment (+200 ppm; 2001-2009) 6 soil (+4 °C; 2007-2012). The study contained two key species, Larix decidua Pinus uncinata, both approximately 40 old, growing heath dominated by dwarf shrubs. In 2012, we harvested measured all trees (including root systems),...
Summary Increased CO 2 emissions and global warming may alter the composition of fungal communities through removal temperature limitation in plant–soil system, faster nitrogen (N) cycling changes carbon (C) allocation host plants to rhizosphere. At a Swiss treeline featuring Larix decidua Pinus uncinata , effects multiple years enrichment experimental soil on community organic horizons were analysed using 454‐pyrosequencing ITS amplicons. Sporocarp production colonization ectomycorrhizal...
Treeline responses to climate change ultimately depend on successful seedling recruitment, which requires dispersal of viable seeds and establishment individual propagules in novel environments. In this study, we evaluated the effects several abiotic biotic drivers early tree recruitment across an alpine treeline ecotone. two consecutive years, sowed low- high-elevation provenances Larix decidua (European larch) Picea abies (Norway spruce) below, at, above current into intact vegetation open...
• Rising CO2 concentrations and the associated global warming are expected to have large impacts on high-elevation ecosystems, yet long-term multifactor experiments in these environments rare. We investigated how growth of dominant dwarf shrub species (Vaccinium myrtillus, Vaccinium gaultherioides Empetrum hermaphroditum) community composition understorey larch pine trees responded 9 yr enrichment 3 soil at treeline Swiss Alps. myrtillus was only that showed a clear positive effect growth,...
Understanding the dynamics of treeline ecotones under global change requires long-term ecological and environmental data. The Stillberg research site in Swiss Alps was established 1975 by planting 92,000 seedlings Larix decidua, Pinus cembra mugo ssp. uncinata, has been continuously monitored since then. Here, we present curated data acquired over almost 50 years at site, synthesise major findings. datasets comprise 6.5 million records from 40-year afforestation experiment, as well a 9-year...
Summary How will carbon source–sink relations of 35‐yr‐old larch trees ( Larix decidua ) at the alpine treeline respond to changes in atmospheric CO 2 and climate? We evaluated effects previously elevated concentrations (9 yr, 580 ppm, ended previous season) ongoing soil warming (4 + 4°C). Larch branches were pulse labeled (50 at% 13 July 2010 trace fresh assimilates through tissues (buds, needles, bark wood) non‐structural compounds NCC ; starch, lipids, individual sugars) using...
Global warming can have substantial impacts on the phenological and growth patterns of alpine Arctic species, resulting in shifts plant community composition ecosystem dynamics. We evaluated effects a six-year experimental soil treatment (+4°C, 2007–2012) phenology three co-dominant dwarf shrub species growing understory Larix decidua Pinus uncinata at treeline Swiss Alps. monitored vegetative reproductive Vaccinium myrtillus, gaultherioides Empetrum hermaphroditum throughout early season...
Abstract Trees continuously adjust their axial xylem structure to meet changing needs imposed by ontogenetic and environmental changes. These structure–function responses need be coordinated among competing biophysical constraints avoid failure of the system. Here, we investigated if ontogeny or experimental manipulation CO 2 soil temperature influence these responses. We performed detailed cell anatomical quantification along axis 40‐year‐old Larix decidua trees planted at Swiss tree line...
Abstract Almost all natural terrestrial ecosystems are nutrient limited in terms of growth, and we expect treeline vegetation to be no exception. However, direct constraints low temperature on tissue formation may superimpose effects availability. We examined growth responses two tree ( Larix decidua Pinus uncinata ) dwarf shrub species Vaccinium myrtillus gaultherioides 12 years moderate fertilizer addition (NPK applied at a rate 15 30 kg nitrogen ha − 1 along an elevation gradient within...
Abstract Aim To quantify tree biomass and stand productivity of treeline ecotones identify driving factors. Location seven regions from the South to Polar Urals, spanning a latitudinal gradient 1,500 km. Taxa Picea obovata , Betula pubescens Larix sibirica. Methods Stand were estimated across 18 elevational transects species line closed forest based on allometric measurements 326 trees (including roots for 53 trees), structure assessments demographic patterns 20,600 trees. growth data linked...
Summary To understand how trees at high elevations might use water differently in the future, we investigated effects of CO 2 enrichment and soil warming (separately combined) on relations L arix decidua growing tree line S wiss A lps. We assessed diurnal stem radius fluctuations using point dendrometers applied a hydraulic plant model microclimate potential data as inputs. Trees exposed to for 9 yr showed smaller contractions (by 46 ± 16%) expansions (42 compared with ambient ....
Summary Global warming may accelerate nitrogen (N) transformations in the soil, with potentially large effects N‐poor high‐elevation ecosystems. To gain insight into partitioning of inorganic and organic N inputs within plant–soil system how influences these patterns, we applied a 15 label ( NH 4 Cl or N‐glycine) shortly after snowmelt during sixth year experimental soil (+4 °C) at treeline Swiss Alps. Seven weeks labelling, approximately 60% remained layer to 10 cm depth, whereas recovery...