Forest fires and climate-induced tree range in USA



by LORENZO CIOTTI

Forest fires and climate-induced tree range in USA

The fire causes effects of a different nature. In addition to the panic of the people possibly involved, high temperatures can cause burns or carbonization or serious structural damage in the case of elements in concrete, steel or structural wood, with the difference that the duration of the latter can be scientifically calculated and hence the permissible escape time.

Finally, a lot of damage is caused by harmful gases. For example, the formation of CO2 saturates the environment by depleting the presence of oxygen; in the case of incomplete combustion, carbon monoxide can be formed or in other cases the formation of polluting gases NOx is possible.

Forest fires and climate-induced tree range shifts in the western US, research published on the Nature communications, analyzes: "Due to climate change, plant populations experience environmental conditions to which they are not adapted.

Our understanding of the next century's vegetation geography depends on the distance, direction, and rate at which plant distributions shift in response to a changing climate. In this study we test the sensitivity of tree range shifts (measured as the difference between seedling and mature tree ranges in climate space) to wildfire occurrence, using 74,069 Forest Inventory Analysis plots across nine states in the western United States.

Wildfire significantly increased the seedling-only range displacement for 2 of the 8 tree species in which seedling-only plots were displaced from tree-plus-seedling plots in the same direction with and without recent fire.

The direction of climatic displacement was consistent with that expected for warmer and drier condi tions. The greater seedling-only range displacement observed across burned plots suggests that fire can accelerate climate-related range shifts and that fire and fire management will play a role in the rate of vegetation redistribution in response to climate change." Meanwhile in Anctartica...

Natural disaster in Antarctica: a large giant ice shelf has collapsed into a thousand pieces, as seen in the images captured before and after the breakup by the European Sentinel-2 satellite of the Copernicus program, of the European Space Agency and the European Commission.

This happened after an anomalous heat wave recorded in mid-March, when the temperature in the Antarctic plateau rose more than 40 degrees above normal, marking an unprecedented record with the thermometer indicating the warmest temperature of the period, 11.8 degrees below zero.

The heat wave lasted about a week: the temperature started to rise on March 16, then peaked at -11.8 degrees on March 18 and then gradually returned to normal around March 23. Experts said: "The Antarctic plateau is a white desert, characterized by very dry air, always clear skies and very rare precipitations: in those days, however, humid air arrived, many clouds appeared and it even snowed.

Blame the jet stream, the channeled air flow that at the edge of the troposphere regulates the circulation of perturbations: in mid-March it formed a very narrow loop that slipped over the plateau, bringing with it a mass of humid and mild air that was stationed on the ocean between Antarctica and Australia.

A meteorological anomaly caused by climate change? We still don't know. The models of global warming indicate that this type of extreme events with a hot matrix could become more and more probable and frequent, but at the moment we lack a case study to verify it, that is, we cannot exclude that the episode recorded is the result of chance: for now the temperatures in the Antarctic plateau do not show an upward trend, unlike what we see on the coasts and peninsula of Antarctica as well as in the Arctic." We recall that as reported by Copernicus Climate Change Service, the European climate service, the month of March0 2022 was one of the warmest months ever globally.

The global average temperature for March 2022 was approximately 0.4ºC above the 1991-2020 average. Europe bucking the trend: March was the third coldest in the last 10 years. The problem is more serious in the Arctic, with the fourth warmest March on record.

In Antarctica, daily records for maximum temperatures have been broken. As regards Antarctica, the extent of sea ice for the month of March was 26% below the 1991-2020 average. The areas most affected by the phenomenon were those of the Ross, Amundsen and northern Weddell seas.

Instead, as regards the Arctic, the extent of sea ice was 3% below the 1991-2020 average. Copernicus Climate Change Service: "There has been a contrast in temperature anomalies in Europe, with warmer-than-average conditions in the north and colder-than-average conditions in the south. Cold conditions have spread to northern Africa and Russia."