Earth’s oldest, knotted and scarred pine trees are a boon for forest life. Old growth trees continue to decline around the world (SN: 6/18/18). In Europe, the remaining patches of forest with plentiful old trees constitute just 0.7 percent (or just under 3.5 million acres) of the continent’s forested area. This paper and others like it “are really good, because they show how important old growth is,” says Joseph Birch, an ecologist at Michigan State University in East Lansing who wasn’t involved with the research. This line of work serves as a reminder that we need to have a long-term perspective on old growth trees. “We need to be managing and conserving the forests that we have now, even if they’re younger, so that our descendants in a few hundred or even thousand years can have more old growth on the landscape,” Birch says. While the pines’ old age, potentially hundreds of years old, was intriguing to plant physiologist Sergi Munné-Bosch and ecophysiologist Ot Pasques, both at the University of Barcelona, they have also been curious how aging and tree decay affect the broader forest ecosystem, with different life and decay stages providing differing habitat needs to plant, animal and lichen species. Prior studies tended to look at how individual trees aged. So Munné-Bosch and Pasques decided up the ante. They studied young, adult and extremely old mountain pines in five different areas of the Spanish Pyrenees mountains. The duo calculated the trees’ ages based on tree trunk girth. (The two traits are correlated, eliminating the need to bore a sample out of the trunk to count tree rings). The team also weighed and measured needles, buds and shoots, analyzed the trees’ tissues for biochemicals linked to stress, decay and growth and noted age-related physical traits in the trees — such as exposed roots, fissured bark and lightning scars. Data on other species living in or on the trees were also recorded.
2024-02-23 10:30:00
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