Phosphorus, Not Nitrogen, Limits Primary Succession
From Science Advances: “Current models of ecosystem development hold that low nitrogen availability limits the earliest stages of primary succession, but these models were developed from studies conducted in areas with temperate or wet climates. We combine field and microcosm studies of both plant and microbial primary producers and show that phosphorus, not nitrogen, is the nutrient most limiting to the earliest stages of primary succession along glacial chronosequences in the Central Andes and central Alaska. We also show that phosphorus addition greatly accelerates the rate of succession for plants and for microbial phototrophs, even at the most extreme deglaciating site at over 5000 meters above sea level in the Andes of arid southern Peru.”
Read more about the factors affecting plant succession in cold-arid regions here.
Tidewater Glacier Surges Initiated at the Terminus
From Journal of Geophysical Research: “There have been numerous reports that surges of tidewater glaciers in Svalbard were initiated at the terminus and propagated up‐glacier, in contrast with downglacier‐propagating surges of land‐terminating glaciers. We present detailed data on the recent surges of two tidewater glaciers, Aavatsmarkbreen and Wahlenbergbreen, in Svalbard. High‐resolution time series of glacier velocities and evolution of crevasse patterns show that both surges propagated up‐glacier in abrupt steps. Geometric changes near the terminus of these glaciers appear to have led to greater strain heating, water production, and storage at the glacier bed. Water routing via crevasses also likely plays an important role in the evolution of surges.“
Find out more about this proposed mechanism of glacier surges here.
Hexachlorobenzene Accumulation in Svalbard Fjords
From Springer: “In the present study, we investigated the spatial and historical trends of hexachlorobenzene (HCB) contamination in dated sediments of three Svalbard fjords (Kongsfjorden, Hornsund, Adventfjorden) differing in environmental conditions and human impact. HCB concentrations ranging from below limit of quantification (6.86 pg/g d.w.) to 143.99 pg/g d.w. were measured… In case of several sediment cores, the HCB enrichment in surface (recent) sediments was noticed. This can indicate importance of secondary sources of HCB, e.g., the influx of HCB accumulated over decades on the surface of glaciers. Detected levels of HCB were generally low and did not exceed background concentration levels; thus, a negative effect on benthic organisms is not expected.”
Discover more about organic pollutions in Norway here.
From The Telegraph: “President Vladimir Putin on Wednesday visited an Arctic archipelago, part of Russia’s efforts to reaffirm its foothold in the oil-rich region. On a tour of the Franz Josef Land archipelago, a sprawling collection of islands where the Russian military has recently built a new runway and worked to open a permanent base, Mr Putin emphasized the need to protect Russia’s economic and security interests in the Arctic… During the visit, Putin inspected a cavity in a glacier that scientists use to study permafrost. He also spoke with environmental experts who have worked to clean the area of Soviet-era debris.”
From adn.com: “Matanuska Glacier is the most user-friendly glacier in Alaska — one of few major ice sheets in the world that visitors can drive to and explore on foot. The glacier sits along a scenic stretch of the Glenn Highway about two hours from Anchorage, a frozen river sprawling almost 30 miles from the 13,000-foot heights of the Chugach Mountains to a toe hundreds of feet deep and miles wide that offers unique glimpses of usually buried formations. The only road-accessible route to the ice is through property owned by Matanuska Glacier Park LLC… Before November, a tour was just one option for glacier-goers who wanted to spend several hours with a guide on a trail that loops past frozen caves, tunnels and canyons and avoids hidden crevasses, water-filled pits or holes that can descend hundreds of feet into the ice. But that month, Matanuska Glacier Park began requiring any first-time winter visitor without glacier travel experience to pay for a tour — like it or not.”
Downward Trend of Organic Pollutants in Antarctica
From Chemosphere: “Passive air samplers were used to evaluate long-term trends and spatial distribution of trace organic compounds in Antarctica. Duplicate PUF disk samplers were deployed at six automatic weather stations in the coastal area of the Ross sea (East Antarctica), between December 2010 and January 2011, during the XXVI Italian Scientific Research Expedition… In general, the very low concentrations reflected the pristine state of the East Antarctica air. Backward trajectories indicated the prevalence of air masses coming from the Antarctic continent. Local contamination and volatilization from ice were suggested as potential sources for the presence of persistent organic pollutants in the atmosphere.”