Treets venner holder for tiden på å lage en uttalelse om forslaget til ny norsk standard for verdivurdering av trær —> Se mer her…
Hvis du har innspill til dette, kan du sende forslag til Eirik Wærner på erw@multiconsult.no. Hvis du vil ha høringsforslaget som pdf, kan du også sende mail til Eirik. Frist for innspill er kort, da høringsuttalelser må være levert 20. april.
Bymiljøetaten i Oslo kommune har laget en flott PDF om byens trær. Fra forordet:
«Denne brosjyra gir et innblikk i flere sider ved trær i by. Vi ønsker å synliggjøre Oslotrærnes mange kvaliteter og særpreg. Forhåpentligvis kan brosjyra bidra til økt forståelse for bytrærnes verdi og plass i bybildet. Dette fjerde opplaget av “Byens trær” inneholder også noen tips om hvordan du kan plante trær.»
Absolutt leseverdig for alle trevenner. Last den ned her!
Every year, about 15 billion trees are cut down to make way for agriculture, mining, logging, and urban sprawl. Such mass deforestation has accelerated global warming and imperiled the survival of millions of species. Though many nations, organizations, and even individuals have tried, no one has been able to plant enough trees to make up for that loss—but some innovative entrepreneurs are working on a high-tech solution.
BioCarbon Engineering (BCE), a U.K.-based start-up, has developed a technique that they say could potentially plant one billion trees per year. The method? Drones.
Current tree-planting programs «are just not fast enough,” said Irina Fedorenko, a co-founder of the company. “But our technology is automated, so we can scale up quite realistically and quite quickly.” (Learn about the teenager who is on track to plant a trillion trees.)
Trees are critical to absorbing the greenhouse gases that contribute to global warming. Without them, the speed and severity of climate change will continue to escalate. But for their part, BCE has dubbed their strategy “industrial-scale reforestation.”
First, a drone scans the terrain and develops a 3-D map of the area. Then, using the data from this “smart map,” the team develops an algorithm for a unique planting pattern. A “firing drone” uses the algorithm to carry out the planting strategy. The drone flies about six feet above the ground, firing germinated seed pods at a speed that will get them under the soil. One drone operator can manage six drones.
It’s similar to strategies used for precision farming, except in this case, the firing drones take the place of tractors—“sky tractors,” as Fedorenko refers to them.
The system’s designers say their technique is much more efficient and accurate than regular aerial seeding methods. Initial testing in the U.K. found that the species planted by drone had a better survival rate than helicopter spreading that’s more commonly used. Some species even had survival rates nearly identical to hand planting.
“We are bridging this gap between ground-based technologies like tractors and aerial technologies such as helicopters,” Fedorenko says.
Speed is the most revolutionary aspect of BCE’s “precision planting” technology, but the drones can also reach places that tractors and humans cannot, at least without significant bodily risk—for example, steep mountainsides or areas with contaminated soil. Drones may even one day help terraform other planets.
But it’s not just about trees: “We have a title of tree-planting drone company, but we also do grasses, bushes, flowers, and a lot of fungi,” Fedorenko says. “It’s about restoring what is right for the environment, not just trees.”
INDIA MAN PLANTS FOREST BIGGER THAN CENTRAL PARK TO SAVE HIS ISLAND
This film is part of National Geographic’s Shortfilm Showcase, and any views expressed here belong to the filmmakers.
Pioneer plant species are usually the most successful, “but the general rule is that if you can restore the forest from seeds, then you can use drones to do that,” Fedorenko says.
In June, BioCarbon planted 5,000 trees in a day to rehabilitate land ravaged by coal mining in Dungog, Australia. They’ve also worked in South Africa and New Zealand. Since the company’s inception, they’ve used drones to plant more than 25,000 trees across the globe.
“If you re-forest a large area of land, you bring back not just fertile soil, but you can really impact local climate, improve the water table, carbon sequestration, increase biodiversity, and, of course, landscapes are never empty so you always have people who are benefiting from the ecosystem,” Fedorenko says.
Experts caution that planting itself is not always as important as protection from factors such as overgrazing, agriculture, and fires, to allow natural regeneration of forests to occur. Some experts worry that the efficiency of drone reforestation could even lower motivation for countries to save existing forests. Additionally, in traditional reforestation enterprises, the planting work can provide employment for communities that need it—jobs that could one day be replaced by drones.
«It’s probably easier, in the short term, to plant trees with a drone than fix the issues on the ground, but in the long run, that fix is necessary,» says Richard Houghton, a senior scientist at the Woods Hole Research Center, a climate change think tank based in Massachusetts. «A technical fix is generally easier than social change, but not as long lasting.»
With constantly improving GPS and imaging technologies, experts agree that drones have become very useful for accurately mapping large swaths of land and measuring tree and vegetation growth or degradation—even mapping carbon sequestration. But some scientists are more skeptical about their success as a planting technology to combat deforestation on a large scale. For one thing, they only have so much range and battery life.
«Drones are good for measuring secondary growth and looking at where the forest is coming back, but you fight deforestation at a socioeconomic level,» says Arturo Sanchez, director of the University of Alberta’s Center for Earth Observation and Sciences. «The issue of climate change is not forest restoration, the issue is energy. It is controlling coal plants, power plants, automobile emissions. Planting trees is very important, but when you look at the distribution of CO2 emissions, deforestation accounts for 10 to 15 percent. The rest is energy. That’s what needs to be controlled.»
Fedorenko acknowledges that drones alone cannot eliminate all the causes or impacts of deforestation, but she says they could become a useful tool. (See how drones set controlled burns by shooting fireballs.)
BCE just started work on a large-scale project to plant mangroves in Myanmar, incorporating this integrated approach to ecosystem restoration. Mangroves in Myanmar’s low-lying Ayeyarwady Delta have been decimated by years of deforestation for agriculture and aquaculture—eighty-four percent of the original mangrove cover is gone.
“Mangroves have huge potential to actually save people’s lives because they protect coastal communities from tsunamis,” Fedorenko says. “Not only do they have an impact on the ecosystem, like fish stocks, so that people can maintain their livelihoods, but they are also a literal shield from the ocean.”
Their tangled roots also protect coastal areas from erosion.
The project spans more than 600 acres and involves a “holistic” approach to measuring success: BCE will be partnering with an NGO to work with local women farmers, training and employing them to collect and prepare the seeds, as well as monitor the ecosystem as the project progresses. BCE will be able to assess whether the mangroves are growing successfully in less than a year.
Mangrove forests are also some of the most carbon-rich habitats on the planet, sequestering carbon up to 100 times faster than terrestrial forests. That means they’re incredibly efficient at mitigating the impact of global warming.
The project is one step closer to BCE’s main goal: “Of course, our ultimate ambition is to stop climate change,” Fedorenko says with a smile.
Clip source: Promoting health and wellbeing through urban forests – Introducing the 3-30-300 rule | IUCN Urban Alliance, by Prof. Cecil Konijnendijk van den Bosch
Clip source: Promoting health and wellbeing through urban forests – Introducing the 3-30-300 rule | IUCN Urban Alliance
Urban forests provide a wide range of essential benefits. Current global challenges, such as climate change, environmental degradation, and the COVID-19 pandemic, have resulted in increased awareness of the importance of urban trees and green spaces. When working with cities, national governments, and international organisations, I am often asked for specific guidelines for developing successful urban forestry programs. I have mostly declined, because every city is different, which makes it difficult to set transferable targets across various contexts and settings for e.g., urban tree canopy cover.
However, the current state of research and practice, the urgency to green our cities and neighbourhoods, and the call for guidance from decision makers have made me to reconsider. While situations will always be complex and different, and guidelines are not written in stones, I would like to argue for a new rule of thumb for urban forestry and urban greening: the 3-30-300 rule. This rule focuses on the crucial contributions of urban forests and other urban nature to our health and wellbeing. It also recognises that we have to consider many different aspects of the urban forest in order to be successful. It also addresses the need for urban forests to percolate into our living environments. At the same time, it is straightforward to implement and monitor.
The first rule is that every citizen should be able to see at least three trees (of a decent size) from their home. Recent research demonstrates the importance of nearby, especially visible, green for mental health and wellbeing. During the COVID-19 pandemic, people have often been bound to their homes or direct neighbourhoods, placing even greater importance on nearby trees and other green in gardens and along streets. The Danish municipality of Frederiksberg has a tree policy that calls for every citizen to see at least one tree from their house or apartment. We should take this one step further.
Studies have shown an association between urban forest canopy and, for example, cooling, better microclimates, mental and physical health, and possibly also reducing air pollution and noise. By creating more leafy neighbourhoods, we also encourage people to spend more time outdoors and to interact with their neighbourhoods (which in turn promotes social health). Many of the most ambitious cities in the world in terms of greening, including Barcelona, Bristol, Canberra, Seattle, and Vancouver, have set a target of achieving 30% canopy cover. At the neighbourhood level, 30 percent should be a minimum, where cities should strive for even higher canopy cover when possible. Where it is difficult for trees to grown and thrive, e.g. in arid climates, the target should be 30% of vegetation.
Many studies have highlighted the importance of proximity and easy access to high-quality green space that can be used for recreation. A safe 5-minute walk or 10-minute stroll is often mentioned. The European Regional Office of the World Health Organization recommends a maximum distance of 300 metres to the nearest green space (of at least 1 hectare). This encourages the recreational use of green space with impacts on both physical and mental health. Of course it will be important to work with local context, as the needs in e.g., lower-density suburban areas will be different from those in denser urban areas. But also here efforts need to be made to provide access to high-quality urban green space, e.g., in the form of linear green spaces that double as cycle corridors and walking paths.
Applying the 3-30-300 rule will improve and expand the local urban forest in many cities, and with that promote health, wellbeing, and resilience.
About the author: Professor Cecil Konijnendijk van den Bosch is the Director of the Nature Based Solutions Instituteand Program Director (Master of Urban Forestry Leadership) at the University of British Columbia.
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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