People are more likely to protect and conserve what they can see, she explains. \u201cThe whole underlying purpose here is that we want to save forests.\u201d<\/p>\n\n\n\n
Home to many<\/h2>\n\n\n\n
The canopy refers to the uppermost layer of a forest. In temperate regions, treetops average between 30 to 60 metres; while those in the tropics are roughly double that. America\u2019s Pacific Coast and Australia\u2019s southern region boast the world\u2019s tallest trees<\/a> \u2013 redwoods<\/a> and mountain ash<\/a>, respectively \u2013 growing upwards of 100 metres.<\/p>\n\n\n\n Regardless of the location, canopies play many critical roles. And with climate change intensifying, the spotlight on rainforests, which are frequently called the Earth\u2019s lungs, has only grown more intense. <\/p>\n\n\n\n Looking at a canopy\u2019s structure can give you a good idea of how healthy a forest is, says Geoffrey Parker, a forest ecologist at the Smithsonian Environmental Research Center in Washington, DC. \u201cIt is a very good predictor of how much biomass there is in a forest.\u201d<\/p>\n\n\n\n Parker uses lidar, a laser sensor technology, to map the structure of canopies from a bird\u2019s eye view.\u201cForests tend to get \u2018bumpier\u2019 as they get older \u2013 more full of holes and more detailed in how they\u2019re organised vertically inside,\u201d he says. \u201cThose things tend to accommodate higher diversity of species, not just of trees but all the other organisms that rely on the trees.\u201d<\/p>\n\n\n\n A staggering number of species live in the upper layers of forests. \u201cWe now believe that 50% of land-based plants, insects, and animals live in our treetops,\u201d says Lowman. <\/p>\n\n\n\n \u201cI have seen iguanas and various kinds of monkeys and interesting things like macaws that you just can\u2019t see from the ground,\u201d says Parker, who has worked in rainforests throughout the world.<\/p>\n\n\n\n Biologist Andrew Whitworth readily reels off the wildlife he\u2019s spotted in the treetops of Costa Rica, where he heads a nonprofit called Osa Conservation<\/a>: spider monkeys, silky anteaters, olingo racoons, and even small cats called margays. \u201cCanopies have an umbrella effect \u2013 they provide habitats and food resources to so many other species,\u201d he says.<\/p>\n\n\n\n That includes plants too. \u201cThere\u2019s orchids and bromeliads, and also blueberry bushes,\u201d says Sybil Gotsch, an associate professor of biology at Pennsylvania\u2019s Franklin and Marshall College, of the canopies she\u2019s studied. \u201cThere\u2019s also trees within trees \u2013 I once found a 10-metre-tall hemlock tree on a branch in a pocket of soil on top of a redwood.\u201d<\/p>\n\n\n\n \u201cThe canopy supports a very important component of overall diversity in the forest,\u201d says Glen Reynolds, director of the South East Asia Rainforest Research Partnership (SEARRP) in Borneo, Malaysia.<\/p>\n\n\n\n That\u2019s because it\u2019s \u201cthe interface between the atmosphere and biosphere,\u201d he says, where photosynthesis, gas exchange, and other important chemical processes take place. It\u2019s also where most fruits and flowers are found, and thus where pollination occurs. \u201cAlmost all the important stuff goes on there.\u201d<\/p>\n\n\n\n Yet, only an estimated one-tenth of canopy species has been studied. Access is the main limiting factor. For years, researchers had to rely on catapults and slingshots to shoot ropes over a target branch high up in the canopy and haul themselves up in harnesses. Lowman herself pioneered a number of climbing methods, many of which were inspired by spelunking and rescue techniques.<\/p>\n\n\n\n But climbing \u201ctakes time, and is exhausting and dangerous\u201d, says Bartosz Majcher, a researcher at the University of Hong Kong who is doing a PhD on canopy ecology.<\/p>\n\n\n\n Thankfully, the past two decades have witnessed the introduction of cranes and canopy towers, and the adoption of modern technologies such as drones, lidar and remote sensors \u2013 all of which have made it easier to access canopies. But there are drawbacks too, cost being a major one. Additionally, cranes cover only a small area, while surveillance technology doesn\u2019t always provide sufficiently granular data. And so ropes remain the go-to method at many sites.<\/p>\n\n\n\n Still, progress in treetop science can be frustratingly slow. \u201cCanopies have been described as the last biotic frontier<\/a>,\u201d says \u200b\u200bMajcher. \u201cMillions of species live there, and we\u2019ve accessed only a minute proportion of them.\u201d<\/p>\n\n\n\n \u201cWe can be sure we\u2019re losing things before we\u2019re finding them,\u201d adds Lowman.<\/p>\n\n\n\n Which is where her latest conservation project comes into play. Launched in November 2020, Mission Green aims to construct 10 canopy walkways in forests that are considered biodiversity hotspots. These include sites in Mozambique, Madagascar, India, Bhutan, Peru and North America. Two \u2013 in California and Penang, Malaysia \u2013 are already up and running.<\/p>\n\n\n\n \u201cMany, many acres of forests have disappeared and continue to disappear,\u201d explains Lowman. \u201cSo we have to become more strategic and save those places that have future \u2018genetic libraries\u2019 for our children and grandchildren to work with.\u201d <\/p>\n\n\n\n \u201cIt kind of shortcuts conservation if we can save a lot more species in the highest biodiversity areas first,\u201d she says. <\/p>\n\n\n\n Conserving canopies isn\u2019t just important from a biodiversity perspective, but also as a guard against climate change.<\/p>\n\n\n\n For species that dwell in the understorey, the canopy \u201ccreates a buffer to stresses in the environment\u201d by acting as a \u201cgatekeeper between the atmosphere and ground,\u201d says Gotsch. The architecture and physiology of a canopy govern a forest\u2019s microclimate, helping to keep it cooler than its surroundings by intercepting rainfall, slowing wind speed, and influencing the rate of evaporation and transpiration. <\/p>\n\n\n\n \u201cThis buffering effect is quite large,\u201d says forest ecologist Pieter de Frenne from Belgium\u2019s Ghent University. In a meta-analysis of more than 70 forest sites scattered across five continents, de Frenne discovered that daytime temperatures within a forest are on average 4C cooler<\/a> than outside. That difference increases in hotter climes, sometimes by as much as 15C.<\/p>\n\n\n\n \u201cThat means that this thermal regulation, this protective sheltering layer of canopies becomes more important with climate change,\u201d he says.<\/p>\n\n\n\n In addition, a forest\u2019s upper layers help suck carbon dioxide from the air. Estimates suggest that maintaining current carbon uptake by forest canopies and avoiding emissions resulting from deforestation can deliver up to 50% of the carbon mitigation<\/a> needed for us to stay within our 2C limit. That\u2019s because protecting canopies means protecting the biggest trees, which are much larger carbon sinks compared to \u201clots of little spindly trees,\u201d says Whitworth. \u201cIn terms of storage, they\u2019re hugely important.\u201d<\/p>\n\n\n\n It\u2019s for all these reasons that Lowman\u2019s Mission Green comes at a critical juncture. The \u201cbeautiful thing\u201d is that the walkways will help make canopies more accessible,\u201d says Gotsch, \u201cso that people can see, value and appreciate them, and then hopefully help to conserve and study them.\u201d<\/p>\n\n\n\n Reynolds from SEARRP agrees, pointing to Penang\u2019s Langur Way Canopy Walk<\/a> \u2013 one of Mission Green\u2019s two maiden walkways \u2013 as an example. \u201cIt\u2019s really well done, I applaud them for putting in a structure that allows anybody from a five-year-old to a 90-year-old, even special needs people in wheelchairs, into a forest canopy.\u201d<\/p>\n\n\n\n Getting to the walkway is easy. From the park entrance, it\u2019s a five-minute stroll along a gentle shaded path. Stepping onto the 230-metre-long suspension bridge, a breathtaking vista immediately opens up: on the right, you can look to the horizon and see the glittering sea along Malaysia\u2019s western coast, beyond the thicket of trees that is one of three virgin jungle reserves on Penang Island. To the left, the dense lushness of the tropical rainforest strikes you up close as a tangle of lianas, epiphytes and ferns amidst the crowns of dipterocarp hardwood trees. Looking down, you spot the carpeted forest floor some 40 metres away.<\/p>\n\n\n\n On a recent afternoon in late July, a half dozen dusky leaf langurs \u2013 small, friendly, seemingly bespectacled monkeys that are the walkway\u2019s namesakes \u2013 clambered nimbly upon its railings. One dozed in the branch of a nearby tree, as Asian bluebirds and racket-tailed drongos, and even a black giant squirrel, flitted by. <\/p>\n\n\n\n \u201cIt really brings that sense of the last frontier of rainforests into people\u2019s view,\u201d says Reynolds, who isn\u2019t involved in the Penang walkway but has visited numerous times. <\/p>\n\n\n\n \u201cAs an environmental education outreach facility, I think it\u2019s amazing,\u201d he says. Up to 300 people come to the walkway daily, and prior to the pandemic, more than 5,000 students visited every year.<\/p>\n\n\n\n![\"A](\"https:\/\/dialogue.earth\/content\/uploads\/2022\/10\/20221021_Forest-canopies-Penang_Sandy-Ong_12-scaled.jpg\")
<\/div>Protecting canopies means protecting the biggest trees<\/blockquote> Andrew Whitworth, Osa Conservation<\/cite><\/div><\/div>\n\n\n\n
A big unknown<\/h2>\n\n\n\n
![\"A](\"https:\/\/dialogue.earth\/content\/uploads\/2022\/10\/20221021_Forest-canopies_Sandy-Ong_0901.jpg\")
<\/div>Vanguard against global warming<\/h2>\n\n\n\n
![\"The](\"https:\/\/dialogue.earth\/content\/uploads\/2022\/10\/20221021_Forest-canopies_Sandy-Ong_0886.jpg\")
<\/div>A necklace of walkways<\/h2>\n\n\n\n
![\"People](\"https:\/\/dialogue.earth\/content\/uploads\/2022\/10\/20221021_Forest-canopies-Penang_Sandy-Ong_6.jpg\")
<\/div>![\"View](\"https:\/\/dialogue.earth\/content\/uploads\/2022\/10\/20221021_Forest-canopies-Penang_Sandy-Ong_7.jpg\")
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