Alarming the decline of old trees

(The biggest living creature on the planet, the great old trees are home to countless other birds and wild animals, dying.

A report made by three of the world's leading ecologists published in the journal Science warns of an alarming increase in the mortality rates of old trees aged 100- 300 years in many forests of the world, forests, deserts, agricultural areas and even cities.

"It is a worldwide problem and happening in almost every forest type," said lead researcher Professor David Lindenmayer of the Center for Excellence for Environmental Decisions (CEED) and Australian National University (Australian National). University) said.

"Big old trees are very important in many natural environments and man-dominated environments. Studies of ecosystems around the world show that these populations of ancient trees are declining. quickly, " said David Lindenmayer and colleagues, Professor Bill Laurance of James Cook University, Australia, and Professor Jerry Franklin of the University of Washington, USA, in their scientific report.

"Research is needed to determine the cause of the rapid disappearance of large old trees and to provide management strategies to improve the situation. Lack of policy changes, ancient trees. Large receptors will decrease or disappear in many ecosystems, leading to a decline in their ecosystem functions and related ecosystems. "

Professor Lindenmayer said they first reported the loss of ancient trees while checking Swedish forest data back to the 1860s. Then a 30-year study of Mountain Forest Ash (Eucalyptus regnans) in Australia has confirmed that not only old trees are dying massively in wildfires, but also ten times worse than the normal rate of a year without fire - obviously due drought, high temperature, logging and other causes.

Looking around the world, scientists find similar trends at all latitudes, California's Yosemite National Park, on the African deserts, in Brazil's rainforests, temperate forests of Europe and northern forests far north. The decline in large-sized trees has also been claimed in agricultural areas and even cities, where people make efforts to conserve them.

"It is a very, very disturbing trend. We are talking about the disappearance of the largest living organisms on the planet, the largest flowering plants on the planet, of the organisms that play one. important role in adjusting and enriching our world " , said Professor Bill Laurance of James Cook University.

Large old trees play an important ecological role to provide nesting places or shelters for about 30% of birds and animals in some ecosystems. They store a large amount of carbon. They regenerate nutrients in the soil, creating a rich habitat and affecting the flow of water in the landscape and microclimate.

"Big trees provide abundant food for countless animals including fruits, fruits, leaves and nectar. Tree holes provide nests and shelters for birds and animals, for example The species of the opium (Gymnobelideus leadbeateri) - Australia's endangered animal and its loss could be synonymous with extinction for these organisms. "

"In agricultural areas, large old trees can be the focal point for the restoration of vegetation, they help to connect the landscapes by acting as stone steps for many animals that disperse seeds. and pollen , " he said.

The alarming decline in the number of ancient trees in many types of forests appears to be motivated by a combination of forces, including deforestation for soil, agricultural activities, human changes. created in fire mode, logging and collecting wood, insect attack and climate change fast, Professor Jerry Franklin said.

"For example, populations of ancient pine trees in the dry forests of the Northwestern United States fell sharply in the last century due to selective logging, unusual forest fires, and other causes," he added. .

The researchers compared the loss of global trees with the tragedies that happened to the world's largest mammals such as elephants, rhinos, tigers and whales, warning that almost nowhere else does the dialogue program have time frames of the last century, this is necessary to ensure the existence of ancient trees.

"Just as large animals like elephants, tigers and mammals have plummeted in many parts of the world, the evidence is showing that large-sized old trees can be threatened. scare , "scientists warn.

Scientists call for an urgent worldwide investigation to assess the extent to which large trees are lost, and to identify areas where large trees have a better chance of survival. .

Their article "The rapid decline of large worldwide trees" ("Rapid Worldwide Declines of Large Old Trees) by David B. Lindenmayer, William F. Laurance and Jerry F. Franklin appears in the matter. today of Science magazine.