Summer snowline altitude gradients in Western Norway are influenced by maritime climate

Mountain snowline dynamics are relatively underreported with few studies exploring spatial snowline dynamics. Whilst clear regional-scale relationships between snowline location and temperature exist in European mountains, recent research at higher latitudes reports no response to climate change. In maritime mountains, snowlines occupy complex environmental gradients. Using timeseries of satellite data from Landsat missions 5–8 (151 images between 1984 and 2021), we explored sub-regional summer snowline dynamics across the maritime-continental climate gradient in the Western Norwegian mountains. We characterize spatio-temporal snowline altitude dynamics and investigate the climate factors altering snowline patterns. Summer snowline altitudes were found to increase inland at around double the rate of the 0°C summer isotherm. Data from the European Centre for Medium-Range Weather Forecasts (ECMWF) land component of the fifth generation of European Reanalysis (ERA5-Land), showed a potential ‘maritime-mountain’ effect with coastal orographic snowfall and cloud cover-induced surface solar downwelling radiation amplifying maritime-continental snowline altitude gradients alongside surface atmospheric temperature. This was replicated in the Canadian Rocky Mountains. Between 1984 and 2021, we found spatial summer snowline gradients in Norway decreased and propose multiple climate forcings are responsible, potentially masking links between snowlines and climate change. Although non-significant, the data also suggest regional summer snowline altitudes increased. This study demonstrates the complex spatial heterogeneity in snow-climate relationships and highlights how long-term snow dynamics can be queried using fine-grain (Landsat) resolution satellite data. We share our approach through a Google Earth Engine web-app that rapidly executes spatial snowline analyses for global mountain regions via a graphical user interface.</p

Evolution of a New Class of VEGFR‑2 Inhibitors from Scaffold Morphing and Redesign

Anti-VEGF therapy is a clinically validated treatment for age-related macular degeneration (AMD). We have recently reported the discovery of oral VEGFR-2 inhibitors that are selectively distributed to the ocular tissues. Herein we report a further development of those compounds and in particular the validation of the hypothesis that aminoheterocycles such as aminoisoxazoles and aminopyrazoles could also function as effective “hinge” binding moieties leading to a new class of KDR (kinase insert domain containing receptor) inhibitors

Botanical districts of historical herbarium data in Cornwall.

<p>Showing study area and botanical districts that were used in this research. Figure adapted from Davey [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191021#pone.0191021.ref058" target="_blank">58</a>].</p

Mann-Whitney U test U and p values for pairs of environmental and climate indictor values (EV and CV, respectively).

<p>Only the significant results are shown (p value < 0.05).</p

Example of pre-1900 and post-1900 changes in geographical distributions of plant species in West Cornwall.

<p>Showing present (only present) and past (only past) geographical distributions, intersect (showing overlap of present and past distributions), and loss for: a) Intersect <i>Carex extensa</i> b) Loss for <i>Carex extensa</i>; c) Intersect for <i>Mentha pulegium</i>; d) Loss for <i>Mentha pulegium</i>; e) Intersect for <i>Achillea ptarmica</i>; f) Loss for <i>Achillea ptarmica [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191021#pone.0191021.ref066" target="_blank">66</a>]</i>.</p

The minimum, median and maximum value for each Ellenberg value (EV), light (L), moisture (M), nitrogen (N) and climate indictor value (CV), mean January temperature (Tjan), mean July temperature (Tjul), and mean precipitation (RR).

<p>The minimum, median and maximum value for each Ellenberg value (EV), light (L), moisture (M), nitrogen (N) and climate indictor value (CV), mean January temperature (Tjan), mean July temperature (Tjul), and mean precipitation (RR).</p

Species with the largest change in geographical distribution (in terms of the lost area) in West Cornwall.

<p>Species with the largest change in geographical distribution (in terms of the lost area) in West Cornwall.</p

Classifications for three climate indicator values (CV): Mean January temperature (Tjan), mean July temperature (Tjul), and mean precipitation (RR).

<p>Classifications for three climate indicator values (CV): Mean January temperature (Tjan), mean July temperature (Tjul), and mean precipitation (RR).</p

Geo-referencing of pre-1900 plant species data.

<p>Showing geo-referenced herbarium data with 1.5 km uncertainty buffers [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191021#pone.0191021.ref066" target="_blank">66</a>].</p

Alpine vegetation community patterns in the Khumbu region, Nepalese Himalaya

The Himalayan alpine zone (HAZ)—a high-altitude zone above approximately 4,100 m.a.s.l., is projected to experience strong eco-environmental changes with climate change. As plants expand their range in this region, other processes are likely to be impacted; for example, flows and stores of water. A first vital step in conceptualizing HAZ ecohydrology is to understand the distribution pattern of HAZ vegetation communities. Satellite remote sensing provides one means of doing so, but the often patchy distribution of alpine vegetation creates challenges when using coarse-grained satellite data whose pixels are typically coarser than the grain of vegetation pattern. Here we use fine spatial resolution satellite imagery from WorldView-2 (2 m2 per pixel) coupled with elevation model data from the Copernicus GLO-30 product to produce a land cover classification for the HAZ. Field data captured during in situ surveys in the Gokyo valley, Nepal, were used to drive and then test a random forest classifier. Grassy meadows and dwarf shrubs belonging to the Rhododendron and Juniperus families dominate the ecology of the alpine zone in this region, so we created three vegetation classes for mapping indicative major plant communities dominated by these species. We found that altitude and aspect were dominant drivers of vegetation distribution in the HAZ and that the average vegetation cover of Rhododendron spp. and Juniperus spp. reduces with increasing altitude, as expected. South- and east-facing slopes were dominated by Juniperus spp., whereas north- and west-facing slopes were dominated by Rhododendron spp., and the growth extent of Rhododendron spp. (between 4,010 and 4,820 m.a.s.l.) and meadow (between 4,010 and 4,680 m.a.s.l.) were vertically wider than that of Juniperus spp. (between 4,010 and 4,660 m.a.s.l.). Results from this study demonstrate the vegetation distribution pattern in HAZ at the plant community level and provide an impetus for further studies that seek to understand ecohydrological interactions between dwarf plants and water flows and stores in the HAZ.</p