Kategoriarkiv: Viten om trær

Landskap som er bra for både folk og biomangfold

Hvordan kan vi forvalte jordbruksland, skoger og utmarksområder for å svare på den tredoble utfordringen fra antropocen – tap av biologisk mangfold, klimaendringer og uholdbar arealbruk? Når de administreres ved å bruke biodiversitetsbaserte teknikker som agroskogbruk, silvobeite, diversifisert jordbruk og økosystembasert skogforvaltning, kan disse sosioøkonomiske systemene bidra til å opprettholde biologisk mangfold og gi habitatforbindelser, og dermed utfylle beskyttede områder og gi større motstandskraft mot klimaendringer. Samtidig kan
bruk av disse forvaltningsteknikkene forbedre avkastningen og lønnsomheten mer bærekraftig, og øke levebrødet og matsikkerheten.

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Old trees have much to teach us

Old trees have much to teach us                   
An expansive global history explores humanity’s vexed relationship with venerable plants.  Baobabs are the longest-lived trees in Africa. Credit: Bernard Castelein/Nature Picture Library
Elderflora: A Modern History of Ancient Trees Jared Farmer Basic (2022)
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About 45 million years ago, when the Arctic was ice-free, the world’s earliest known mummified trees flourished on what is now Axel Heiberg Island in Canada’s Qikiqtaaluk Region. In 1986, palaeobotanists identified the megaflora as members of Metasequoia occidentalis, an extinct redwood species. They had been buried in silt, then frozen, their wood preserved.

The lead palaeontologist “celebrated his eureka by kindling a fire with 45-million-year-old twigs and boiling water for tea time,” writes historian Jared Farmer in Elderflora, his expansive global history of grand and venerable trees. Granted, these plants had been dead since the Eocene epoch. Nevertheless, as the author describes, the incident is part of a troubling pattern in which scientists rejoice at their discovery of the ‘oldest’ tree of their time — and then destroy it.

In 1957, for example, Edmund Schulman at the University of Arizona in Tucson spent the summer seeking ancient bristlecone pines in California’s White Mountains. He found three more than 4,000 years old, and named them Alpha, Beta and Gamma. Then, in the interests of tree-ring science, he chose to “sacrifice” Alpha, taking snapshots as his nephew and a colleague sawed it down. When the University of Arizona issued a press release titled ‘UA Finds Oldest Living Thing’, Farmer writes, “they say nothing about the thing being dead”.

Schulman’s aim was dendroclimatology — the reconstruction of climates using tree-ring data. That lofty motive cannot be ascribed to those who, in 1881, bored a tunnel into the 2,000-year-old Wawona tree in Yosemite National Park, allowing tourists to drive their cars through the 71.3-metre-high giant sequoia (Sequoiadendron giganteum), since toppled.

Arboreal legends
As Elderflora shows, big, old trees are objects of veneration and vandalism, appearing “in the oldest surviving mythologies and the earliest extant texts”. They were associated with gods and heroes, prophets and gurus: they had pivotal roles in the Mesopotamian Epic of Gilgamesh and in the Polynesian legend of Rātā, who fells a noble tree to carve a canoe. In more recent times, European settlers “dispossessed Indigenous peoples and cleared forests with abandon”. Research shows that, for 8,000 years after the glaciers of the last ice age retreated, forests in the Midwestern United States doubled in biomass (A. M. Raiho et al. Science 376, 1491–1495; 2022). Just 150 years of industrial logging and agriculture erased this carbon accumulation.

It takes a wood to raise a tree: a memoir
“Imperial conquests and industrial revolutions relied on timber,” Farmer writes. “Wood-stock long guns for capturing lands and peoples; naval vessels with mighty masts for transporting the enslaved and the harvests of their labor.” In New Zealand, European settlers decimated the majestic kauri trees, which can live for up to 2,000 years and that once covered 1.2 million hectares of land. The trees’ 50-metre-trunks became ships’ masts; their resin was made into varnish and linoleum.

Like pines, firs, spruces, cedars, cypresses and redwoods, kauri (Agathis australis) is a gymnosperm. These flowerless plants with naked seeds tend to grow slower and live longer than angiosperms, flowering plants that bear fruit. About 25 plant species — most of them conifers — can live for more than a millennium without human assistance, surviving in restricted, vulnerable habitats.

Farmer also offers a global survey of ancient trees that have been protected and exalted. They include olive trees of the Levant (Olea europaea); research published this year shows that these were domesticated about 7,000 years ago for their fruit and oil (D. Langgut and Y. Garfinkel Sci. Rep12, 7463; 2022). In Africa, the baobab (Adansonia sp.) is both the longest-lived tree and the largest, offering shade and shelter, foods, medicines and textiles. Enslaved Africans planted baobabs in the Caribbean; some survive still. Ginkgo biloba, a species that dates back 390,000 years, survived only in China, whence it was spread around the world in the past millennium. A grove of ginkgo trees survived the atomic bombing of Hiroshima in Japan in August 1945, pushing out new buds the following spring.

The planet’s current tree cover, Farmer writes, includes 3 trillion large plants covering about 30% of all land. It is, in fact, expanding. But the new cover consists mostly of shelter belts (trees planted to protect crops or animals), temperate-zone timber crops and tropical plantations of eucalyptus and palm oil. A shrinking proportion of tree cover is made up of species-rich old-growth communities.

Epic loss
“What would humans and nonhumans stand to lose if these survivors all died prematurely? A world of things,” Farmer writes. “Old trees sustain forest communities” with their seeds and litter. Other plants grow on them, and animals live in them. Their roots share nutrients with other organisms via underground fungi. Groups of “Old Ones” are carbon sinks. Large-scale monocultures are shorter-lived and take less greenhouse gas out of circulation.

But even bygone trees of the once-tropical Arctic might offer lessons for a warming world. Palaeobotanist Hope Jahren, in her 2016 memoir Lab Girl, describes how she spent three summers on Axel Heiberg Island, digging “through a hundred vertical feet of time”. Fir, cypress, larch, redwood, spruce, pine and hemlock trees populated this lush conifer forest, with an understory of angiosperms: maple, alder, birch, hickory, chestnut, beech, ash, holly, walnut, sweetgum, sycamore, oak, willow and elm. These plants thrived even through three months of winter darkness and three of constant summer light.

“Here stood one of the great forests of all time,” Farmer writes. Today, as the Arctic warms nearly four times as fast as any other place on Earth, the genomes of species related to the trees of this mummified forest might be adaptable enough for the trees to flourish in a rewarmed planet, he says. Old trees have much to teach us: we would be wise to listen.

Amerikanske naturvernere saksøker nasjonalparkforvaltningen for skadelig strategi for reetablering av sequoiaskog etter skogbrann

Store områder med verneverdig skog av svært store og gamle sequoiatrær er ødelagt av skogbrannene i California. National Park Service (NPS) ønsker å gjenplante sequoia-lunder i nasjonalparkene Sequoia og Kings Canyon, der skogbranner i 2020 og 2021 påførte varig skade på de ikoniske sequoia-skogene. Miljøvernere i California sier det er en stor feil.

Fire grupper anla sak mot NPS 17. november og sa at byråets innsats bryter loven da den inkluderer planting i utpekte villmarksområder der menneskelig involvering i økosystemet er eksplisitt forbudt.

NPS kunngjorde frøplantingsprosjektet tidligere i høst, og sa at det var «bekymret for at naturlig regenerering kanskje ikke er tilstrekkelig til å støtte selvopprettholdende skogholt inn i fremtiden, spesielt ettersom brannene drepte et enestående antall reproduktive sequoiatrær i selve skogholtene.»

Chad Hanson, direktøren for John Muir-prosjektet, en av gruppene som anla sak, bestrider denne konklusjonen. Sequoiaer er blant tresortene som faktisk «avhengig av høyintensitetsild for å reprodusere effektivt,» sa Hanson til CNN. «Naturen trenger ikke vår hjelp,» sa Hanson til CNN. «Vi er ikke ment å være involvert i å stelle den som en hage.»

Les mer på CNN.com her.

Protect old-growth forests in Europe now

Martin Mikoláš, Gianluca Piovesan, Anders Ahlström, Daniel C. Donato, Rhiannon Gloor, Jeňýk Hofmeister, William S. Keeton, Bart Muys, Francesco M. Sabatini, Miroslav Svoboda, Tobias Kuemmerle

Martin Mikoláš1*, Gianluca Piovesan2, Anders Ahlström3, Daniel C. Donato4, Rhiannon Gloor1, Jeňýk Hofmeister1, William S. Keeton5, Bart Muys6, Francesco M. Sabatini7, 1, Miroslav Svoboda1, To b i a s Kuemmerle81Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Prague, Czech Republic. 2Department in Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy. 3Dep artment of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden. 4University of Washington, School of Environmental and Forest Sciences, Seattle, WA, USA. 5Rubenstein School of Environment and Natural Resources and GundInstitute of Environment, University of Vermont, Burlington, VT, USA. 6Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium. 7Alma Mater Studiorum–University of Bologna, Bologna, Italy. 8Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany.*Corr esponding author. Email: mikolasm@fld.czu.cz

Kilde Science Magazine: https://doi.org/10.1126/science.adh2303

Europe’s old-growth forests, such this one in Romania’s Fagaras Mountains, lack sufficient protection. PHOTO: KAROL KALISKÝ, AROLLA FILM

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Old-growth forests harbor high and unique biodiversity, store vast amounts of carbon, are important for water and nutrient cycling, and constitute a unique element of natural heritage (1). In the European Union, old-growth forest protection is now mandated by the EU Biodiversity Strategy for 2030. However, almost 3 years after the strategy’s adoption, stakeholders and policymakers are still discussing definitions and legislative mechanisms, while old-growth forests continue to decline at alarming rates (24).

In March, the European Commission suggested guidelines to map and protect old-growth forests by the end of 2029 (7). However, these guidelines are neither binding nor prescriptive. Given current widespread logging of old-growth stands, the EU is on track to fail its 2030 goals.

Pressure on Europe’s biomass-rich oldgrowth forests is high and rising. Timber prices have increased (8). Compensation would encourage forest owners to adopt strict protection, but there are insufficient resources and tools to provide financial incentives (9). Because landowners anticipate that forest protection will increase in the future, and forest monitoring is sparse, they are motivated to log as much as possible before regulation tightens.

To improve protection, the EU should immediately implement a logging moratorium on areas potentially harboring oldgrowth forests, make resources available to detect old-growth forests, require member states to include old-growth protection in their national strategies, and provide equitable financial tools to ensure their effective protection (10). Exemptions from strict conservation could be considered only for stands managed by well-documented practices that support biodiversity. Without bold and swift action, Europe risks irreparable loss to its natural heritage.

Old-growth forests harbor high and unique biodiversity, store vast amounts of carbon, are important for water and nutrient cycling, and constitute a unique element of natural heritage (1). In the European Union, old-growth forest protection is now mandated by the EU Biodiversity Strategy for 2030. However, almost 3 years after the strategy’s adoption, stakeholders and policymakers are still discussing definitions and legislative mechanisms, while old-growth forests continue to decline at alarming rates (24).

Many old-growth forests are logged before their identification and protection. In Sweden, for example, unprotected boreal oldgrowth forests have been cut at a rate that could lead to their disappearance within the next 50 years (2). Similarly, Romania harbors up to 738,000 ha of potential old-growth forest, but more than 90% of this area lacks strict protection (5). In Romania and elsewhere in Eastern Europe, logging continues across some of the continent’s few remaining large landscapes dominated by temperate old-growth forests (4). Even protected old-growth forests are often salvage logged after natural disturbances (6).

In March, the European Commission suggested guidelines to map and protect old-growth forests by the end of 2029 (7). However, these guidelines are neither binding nor prescriptive. Given current widespread logging of old-growth stands, the EU is on track to fail its 2030 goals.

Pressure on Europe’s biomass-rich oldgrowth forests is high and rising. Timber prices have increased (8). Compensation would encourage forest owners to adopt strict protection, but there are insufficient resources and tools to provide financial incentives (9). Because landowners anticipate that forest protection will increase in the future, and forest monitoring is sparse, they are motivated to log as much as possible before regulation tightens.

To improve protection, the EU should immediately implement a logging moratorium on areas potentially harboring oldgrowth forests, make resources available to detect old-growth forests, require member states to include old-growth protection in their national strategies, and provide equitable financial tools to ensure their effective protection (10). Exemptions from strict conservation could be considered only for stands managed by well-documented practices that support biodiversity. Without bold and swift action, Europe risks irreparable loss to its natural heritage.

Referanser

REFERENCES AND NOTES 1. F. Hua et al., Science376, 839 (2022). 2. A. Ahlström, J. G. Canadell, D. B. Metcalfe, Earth. Fut.10, e2022EF003221 (2022). 3. F. M. Sabatini et al., Sci. Data8, 220 (2021). 4. “Illegal logging of Romania’s natural forests increases despite court threat—new report,” Save Paradise Forests (2022 ); https://www.saveparadiseforests.eu/en/illegal-logging-of-romanias-natural-forests-increases-despite-court-threat-new-report/. 5. C. Munteanu et al., Conserv. Biol. 36, e13820 (2022). 6. M. Żmihorski, P. Chylarecki, A. Orczewska, T. Wesołowski, Science361, 238 (2018). 7. “Commission staff working document: Commission guidelines for defining, mapping, monitoring, and strictly protecting EU primary and old-growth forests” (2023); https://ec.europa.eu/transparency/documents-register/detail?ref=SWD(2023)62&lang=en. 8. A. Dikins, “Wooden market forecast Q1/2023” (Kronus, 2023); https://www.kronus.eu/wooden-market-forecast-q1-2023/. 9. M. Sotirov, T. Schulz, G. Winkel, in How to Balance Forestry and Biodiversity Conservation—A View across Europe, F. Krumm, A. Schuck, A. Rigling, Eds. (2020), pp. 62–75. 10. N. Selva, P. Chylarecki, B. G. Jonsson, P. L. Ibisch, Science368, 1438 (2020)