Endangered cloud forests, clouds and local weather change – watts with that?
by Jim Steele
Trumpet ecosystems of the demagogues collapse and allude to scientific assessments. For example, the International Union for Conservation of Nature (IUCN) has classified the gnarled mossy cloud forest as “critically endangered”. So what is “critically endangered”? The story of the gnarled mossy cloud forest is told.
The gnarled mossy cloud forest is located on the 8 km² Lord Howe Island between Australia and New Zealand. For perspective, 54 islands could fit within the confines of New York City. Still, Lord Howe Island is an evolutionary wonder. Forty-four percent (105) of the island’s plant species and 37 percent of all invertebrate species are found nowhere else in the world. In addition, the island supports the most polar reef of all coral reefs. Lord Howe Island was declared a World Heritage Site in 1982.
The “critically endangered” cloud forest is limited to just 0.1 square miles on the island’s extinct volcanic mountain. The researchers feared that the cloud forest’s unique collection of species would have nowhere to go if global warming disrupted its environment. Accordingly, the IUCN describes ecosystems with such limited distribution as critically endangered. Although the species are confined to a small microclimate, they are very resistant to climate change. It took hundreds of thousands of years for the island’s unique species to evolve from their ancestors (after arriving from Australia, New Zealand, and New Caledonia). During this time they alternately survived ice ages and warm interglacials.
The unchanged geography enables the existence of cloud forests. Most are found in the tropics, where they experience 78-102 inches of annual rainfall. (To perspective, “rainy” Seattle means only 38 inches of rain on average.) The photo above also shows why cloud forests are typically restricted to zones within 220 miles of the coast and above elevations of 1,600 feet. The sea breeze is laden with water vapor. As they rise and cool, steam condenses into clouds. Rising air saturated with water vapor can cool enough to create clouds by climbing over 20-story buildings. The gnarled mossy cloud forest exists around 2,800 feet.
Clouds covering the gnarled mossy cloud forest on Lord Howe Island
As the population increased, land management threatened cloud forests around the world. Due to the small population and steep slopes, the gnarled mossy cloud forest was spared excessive losses. However, as with Hawaii and all of the Earth’s unique island species, introduced species are the greatest threat to extinction. Introduced cats, pigs and goats have damaged Lord Howe Island since the mid-19th century. After people realized this threat, they began programs to conserve the island’s species. Pigs and goats were wiped out in the 1980s, but the island’s plague with introduced rats remains problematic. So far, an established owl and poison bait project have had problems limiting rat populations.
In addition to rats, scientists suggested that the cloud forest was threatened by “moisture loss from falling precipitation and cloud cover due to climate change”. Scientists admitted, however, that their estimates were “based on limited information” and the actual level of threat to the cloud forest could range from “least concern” to “collapsed.” “Least concern” may prove to be the right label as long-term global precipitation data shows a slightly increasing trend in the region.
However, to back up their catastrophic claims, their study alluded to, ill-advised, an exposed 1999 study claiming that CO2-induced warming dried up Costa Rica’s cloud forests by raising cloud heights and allegedly causing the golden toad to die out brought. This climate ascription was absolutely wrong. The cloud forest amphibians were killed by an introduced chytrid fungus that was spread by collectors, researchers, and animal trade animals such as introduced bullfrogs. Notably, the worrying warming and drying proposed actually benefited the amphibians by killing the fungus. Similarly, Lord Howe’s cloud forest vegetation may be threatened by introduced fungi (Phytophthora) that are spread by tourists. As a result, steps are being taken to encourage “social distancing” around endangered native plants.
As in Costa Rica, Lord Howe Island suffers from periodic drought associated with El Nino cycles. The lowest measured rainfall on the island occurred in 1997 during El Nino. Unfortunately, to blame climate change for a short-term drying trend, the researchers ignored the fact that the second lowest precipitation occurred in the cool year 1888 and differed from the 1997 “record low” by nearly 0.3 inches. In addition, research has found that cloud cover is shifting due to El Nino cycles and the Pacific Decadal Oscillation in the Pacific, and regional tree rings show 55 year drought cycles amplified by El Nino.
Ecologists know that surviving cloud forest species had to adapt to natural cycles of periodic drought that they endured for millennia, and they did. One example is the Kentia Palm. Native to Lord Howe Island only, it is a globally popular houseplant, in part because it can withstand long periods of neglect and irregular watering. So take courage. The gnarled mossy cloud forest will not collapse with a changing climate. And while introduced species are certainly a threat, humans correct them.
Jim Steele is director emeritus of the Sierra Nevada Field Campus of the state of San Francisco, author of Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism, and a member of the carbon coalition