Nitrogen enrichment can disrupt symbiotic lichen communities sensitive to ammonia and oxidized forms. Bulk collectors and passive samplers deployed along a coastal–inland transect quantify seasonal deposition fluxes. Lichen tissue nitrogen content and species richness decline with modeled deposition gradients, supporting critical-load thresholds used in regional habitat management plans for open heath vegetation.

Winter supplementary feeding is increasingly used to buffer pasture loss yet may reshape rumen microbial communities. Fecal samples collected before, during, and after pellet supplementation from two herding districts were profiled with shotgun metagenomics. Beta diversity separates feeding phases, with transient enrichment of starch-fermenting taxa that decline within three weeks of return to lichen-dominated diets.

Shorter ice seasons alter thermal structure and stratification in hemiboreal lakes. Analysis of daily ice-on and ice-off dates from citizen-science records spanning six decades, combined with buoy profiles on three reference lakes, shows a significant decline in ice duration correlated with winter air temperature. Extended open-water periods increase epilimnetic heat content by autumn, potentially strengthening fall mixing events.

Post-fire management requires timely maps of canopy consumption and soil exposure. We train a random forest on spectral indices and topographic predictors using field-plot dNBR classes from three recent seasons. Cross-validation by fire event yields balanced accuracy above eighty percent for moderate and high severity classes, outperforming thresholded differenced indices when regenerating mixed conifer stands with residual green canopy.

Thawing permafrost creates ponds with distinct redox stratification that may enhance microbial production of methylmercury. Incubation experiments on surficial sediments from eight ponds spanning pH and sulfate gradients reveal highest methylation rates where pore-water sulfate is low and organic matter is labile. Stable-isotope tracing confirms sulfate-reducing bacteria as the dominant methylators under anoxic conditions typical of late-summer bottom waters.

Expansion of deciduous shrubs alters albedo and nutrient cycling in treeless landscapes. We combine high-resolution multispectral imagery with field transects measuring shrub height and cover along elevation gradients. A modified green–red vegetation index correlates with field biomass estimates and detects gradual encroachment over a twelve-year image stack more consistently than normalized difference vegetation index alone when lichen background dominates.

Spring freshet dominates annual fluxes of dissolved organic carbon from northern peatlands, yet interannual snowpack differences remain poorly quantified. We sampled outlet streams weekly across three low-relief catchments for four hydrological years with contrasting snow water equivalents. Load estimates derived from rating curves show that early melt pulses account for more than half of annual export when winter precipitation is above the long-term median, with implications for downstream drinking-water treatment.