Tree Rings Reveal How Ancient Forests Were Managed
By Katherine Kornei
Clear-cutting a forest is relatively easy—just pick a tree and start chopping. But there are benefits to more sophisticated forest management. One technique—which involves repeatedly harvesting smaller trees every 30 or so years but leaving an upper story of larger trees for longer periods (60, 90, or 120 years)—ensures a steady supply of both firewood and construction timber.
To determine when this management practice first arose in Europe, researchers have analyzed oak construction timbers from historical buildings and archaeological sites dating from the 4th to 21st centuries. They spotted a characteristic tree ring pattern indicative of this technique in timber dating back to the 6th century. That was a surprise, the researchers noted, because this forest management practice shows up in historical documents beginning only in the 13th century.
A Pattern in the Rings
The coppice-with-standards management practice produces a two-story forest, said Bernhard Muigg, a dendrochronologist at the University of Freiburg in Germany. "You have an upper story of single trees that are allowed to grow for several understory generations."
That arrangement imprints a characteristic tree ring pattern in a forest's upper story trees (the "standards"): thick rings indicative of heavy growth, which show up at regular intervals as the surrounding smaller trees are cut down. "The trees are growing faster," said Muigg. "You can really see it with your naked eye."
Muigg and his collaborators characterized that dendrochronological pattern in 161 oak trees growing in central Germany, one of the few remaining sites in Europe with actively managed coppice-with-standards forests. They found up to nine cycles of heavy growth in the trees, the oldest of which was planted in 1761. The researchers then turned to a historical data set — more than 2,000 oak timbers from buildings and archaeological sites in Germany and France dating from between 300 and 2015 — to look for a similar pattern.
A Gap of 500 Years
The team found wood with the characteristic coppice-with-standards tree ring pattern dating to as early as the 6th century. That was a surprise, Muigg and his colleagues concluded, because the first mention of this forest management practice in historical documents occurred only roughly 500 years later, in the 13th century.
It's probable that forest management practices were not well documented prior to the High Middle Ages (1000–1250), the researchers suggested. "Forests are mainly mentioned in the context of royal hunting interests or donations," said Muigg. Dendrochronological studies are particularly important because they can reveal information not captured by a sparse historical record, he added.
These results were published in December in Scientific Reports.
"It's nice to see the longevity and the history of coppice-with-standards," said Ian Short, a forestry researcher at Teagasc, the Agriculture and Food Development Authority in Ireland, not involved in the research. This technique is valuable because it promotes conservation and habitat biodiversity, Short said. "In the next 10 or 20 years, I think we'll see more coppice-with-standards coming back into production."
In the future, Muigg and his collaborators hope to analyze a larger sample of historic timbers to trace how the coppice-with-standards practice spread throughout Europe. It will be interesting to understand where this technique originated and how it propagated, said Muigg, and there are plenty of old pieces of wood waiting to be analyzed. "There [are] tons of dendrochronological data."
Katherine Kornei is a freelance science journalist covering Earth and space science. Her bylines frequently appear in Eos, Science, and The New York Times. Katherine holds a Ph.D. in astronomy from the University of California, Los Angeles.
This story originally appeared in Eos and is republished here as part of Covering Climate Now, a global journalism collaboration strengthening coverage of the climate story.
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Wisdom the mōlī, or Laysan albatross, is the oldest wild bird known to science at the age of at least 70. She is also, as of February 1, a new mother.
<div id="dadb2" class="rm-shortcode" data-rm-shortcode-id="aa2ad8cb566c9b4b6d2df2693669f6f9"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1357796504740761602" data-partner="rebelmouse"><div style="margin:1em 0">🚨Cute baby alert! Wisdom's chick has hatched!!! 🐣😍 Wisdom, a mōlī (Laysan albatross) and world’s oldest known, ban… https://t.co/Nco050ztBA</div> — USFWS Pacific Region (@USFWS Pacific Region)<a href="https://twitter.com/USFWSPacific/statuses/1357796504740761602">1612558888.0</a></blockquote></div>
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Winter is supposed to be the best season for wind power – the winds are stronger, and since air density increases as the temperature drops, more force is pushing on the blades. But winter also comes with a problem: freezing weather.
Comparing rime ice and glaze ice shows how each changes the texture of the blade. Gao, Liu and Hu, 2021, CC BY-ND
Ice buildup changes air flow around the turbine blade, which can slow it down. The top photos show ice forming after 10 minutes at different temperatures in the Wind Research Tunnel. The lower measurements show airflow separation as ice accumulates. Icing Research Tunnel of Iowa State University, CC BY-ND
While traditional investment in the ocean technology sector has been tentative, growth in Israeli maritime innovations has been exponential in the last few years, and environmental concern has come to the forefront.
theDOCK aims to innovate the Israeli maritime sector. Pexels<p>The UN hopes that new investments in ocean science and technology will help turn the tide for the oceans. As such, this year kicked off the <a href="https://www.oceandecade.org/" target="_blank" rel="noopener noreferrer">United Nations Decade of Ocean Science for Sustainable Development (2021-2030)</a> to galvanize massive support for the blue economy.</p><p>According to the World Bank, the blue economy is the "sustainable use of ocean resources for economic growth, improved livelihoods, and jobs while preserving the health of ocean ecosystem," <a href="https://www.sciencedirect.com/science/article/pii/S0160412019338255#b0245" target="_blank" rel="noopener noreferrer">Science Direct</a> reported. It represents this new sector for investments and innovations that work in tandem with the oceans rather than in exploitation of them.</p><p>As recently as Aug. 2020, <a href="https://www.reutersevents.com/sustainability/esg-investors-slow-make-waves-25tn-ocean-economy" target="_blank" rel="noopener noreferrer">Reuters</a> noted that ESG Investors, those looking to invest in opportunities that have a positive impact in environmental, social and governance (ESG) issues, have been interested in "blue finance" but slow to invest.</p><p>"It is a hugely under-invested economic opportunity that is crucial to the way we have to address living on one planet," Simon Dent, director of blue investments at Mirova Natural Capital, told Reuters.</p><p>Even with slow investment, the blue economy is still expected to expand at twice the rate of the mainstream economy by 2030, Reuters reported. It already contributes $2.5tn a year in economic output, the report noted.</p><p>Current, upward <a href="https://www.ecowatch.com/-innovation-blue-economy-2646147405.html" target="_self">shifts in blue economy investments are being driven by innovation</a>, a trend the UN hopes will continue globally for the benefit of all oceans and people.</p><p>In Israel, this push has successfully translated into investment in and innovation of global ports, shipping, logistics and offshore sectors. The "Startup Nation," as Israel is often called, has seen its maritime tech ecosystem grow "significantly" in recent years and expects that growth to "accelerate dramatically," <a href="https://itrade.gov.il/belgium-english/how-israel-is-becoming-a-port-of-call-for-maritime-innovation/" target="_blank" rel="noopener noreferrer">iTrade</a> reported.</p><p>Driving this wave of momentum has been rising Israeli venture capital hub <a href="https://www.thedockinnovation.com/" target="_blank" rel="noopener noreferrer">theDOCK</a>. Founded by Israeli Navy veterans in 2017, theDOCK works with early-stage companies in the maritime space to bring their solutions to market. The hub's pioneering efforts ignited Israel's maritime technology sector, and now, with their new fund, theDOCK is motivating these high-tech solutions to also address ESG criteria.</p><p>"While ESG has always been on theDOCK's agenda, this theme has become even more of a priority," Nir Gartzman, theDOCK's managing partner, told EcoWatch. "80 percent of the startups in our portfolio (for theDOCK's Navigator II fund) will have a primary or secondary contribution to environmental, social and governance (ESG) criteria."</p><p>In a company presentation, theDOCK called contribution to the ESG agenda a "hot discussion topic" for traditional players in the space and their boards, many of whom are looking to adopt new technologies with a positive impact on the planet. The focus is on reducing carbon emissions and protecting the environment, the presentation outlines. As such, theDOCK also explicitly screens candidate investments by ESG criteria as well.</p><p>Within the maritime space, environmental innovations could include measures like increased fuel and energy efficiency, better monitoring of potential pollution sources, improved waste and air emissions management and processing of marine debris/trash into reusable materials, theDOCK's presentation noted.</p>
theDOCK team includes (left to right) Michal Hendel-Sufa, Head of Alliances, Noa Schuman, CMO, Nir Gartzman, Co-Founder & Managing Partner, and Hannan Carmeli, Co-Founder & Managing Partner. Dudu Koren<p>theDOCK's own portfolio includes companies like Orca AI, which uses an intelligent collision avoidance system to reduce the probability of oil or fuel spills, AiDock, which eliminates the use of paper by automating the customs clearance process, and DockTech, which uses depth "crowdsourcing" data to map riverbeds in real-time and optimize cargo loading, thereby reducing trips and fuel usage while also avoiding groundings.</p><p>"Oceans are a big opportunity primarily because they are just that – big!" theDOCK's Chief Marketing Officer Noa Schuman summarized. "As such, the magnitude of their criticality to the global ecosystem, the magnitude of pollution risk and the steps needed to overcome those challenges – are all huge."</p><p>There is hope that this wave of interest and investment in environmentally-positive maritime technologies will accelerate the blue economy and ESG investing even further, in Israel and beyond.</p>
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