Study finds tiny cloud forests have big biodiversity

Nicholas Barrett
June 24, 2014



Cloud forests threatened by global warming, logging

Tropical cloud forests are situated in mountains and are characterized by the frequent presence of low-level clouds. Scientists have always regarded them as having high biodiversity, but a study published recently in mongabay.com's open access journal, Tropical Conservation Science adds a new dimension: it found cloud forests contain a significant and surprising array of tree and bromeliad species, even when they are relatively small.

A team of researchers analyzed the tree biodiversity of four of Mexico’s remaining cloud forests and concluded that, despite the recent retreat of these habitats, many species of trees and bromeliad have endured in relatively high numbers.


A cloud forest in Cuetzalan, Puebla, México.

Bromeliads are a type of flowering plant found in the tropical Americas. They can be ground dwelling, such as pineapple, or they can grow up high in the canopies of trees. Species that fall into the latter category are called “epiphytes.”

To analyze the biodiversity of the Mexican cloud forests, researchers from the Mexican Institute of Ecology (INECOL) established six small plots in each of the four sites, in which they measured the botanical diversity. The team recorded 18 species of epiphytic bromeliads and 45 species of tree, including Quercus delgadoana, an endangered species of oak that turned out to be dominant at one of the sites surveyed. Other species of tree classified as Vulnerable by the IUCN were found to be in relative abundance.

Surprisingly, some of the smallest fragments of cloud forest boasted the highest levels of botanical diversity.

Cloud forests are characterized by persistent low-lying cloud cover. Photo by Prsjl.
Cloud forests are characterized by persistent low-lying cloud cover. Photo by Prsjl.
In the paper, the researchers speculate that forest fragmentation may have led to an increased amount of sunlight exposure in clearings and at the edges of the forests. This may have upset the monopoly of the tall established giants and allowed a greater number of “pioneer species” to grow.

Cloud forests are areas of high altitude woodland distinguished by a frequently low cloud cover. They host a uniquely cool tropical environment, and due to the narrow band of altitude and latitude in which they can grow, they account for only about one percent of the world’s forest.

Because of the highly specialized atmospheric conditions needed to sustain a cloud forest, many, particularly in Mexico, are expected to shrink or vanish outright due to human-caused global warming. Additionally, many cloud forests are currently targeted by logging companies.

The study indicates that these areas could be vital for the conservation of Mexico’s struggling forest habitats. According to the researchers, “even small and disturbed fragments can play an important role as reservoirs of tropical montane cloud forest biodiversity within the severely transformed landscape of the region.”

Unfortunately, the danger posed to these enigmatic woodlands remains prominent. In 2012, the journal Nature Climate Change published a paper warning that human-caused climate change is on course to wipe out 90 percent of Mexico’s cloud forests by 2080, and the loss of these habitats could mean the extinction of as many as 37 vertebrate species.



Citations:
  • Tarin Toledo-Aceves, José G. García-Franco, Guadalupe Williams-Linera, Keith MacMillan and Claudia Gallardo-Hernández. 2014. Significance of remnant cloud forest fragments as reservoirs of tree and epiphytic bromeliad diversity. Tropical Conservation Science Vol.7 (2): 230-243.















    Related articles

    Mountain forests store 40 percent more carbon than expected

    (06/10/2014) It's not easy to measure carbon in mountain forest ecosystems. But a new review study in Biogeosciences found that many estimates of carbon storage in montane tropical forests have been largely underestimated.


    Emerald-faced reptile discovered in Ecuador

    (05/23/2014) Researchers have discovered a colorful lizard species in the cloud forests of northwestern Ecuador.


    Connecting forests, saving species: conservation group plans extensive wildlife corridor in Panama

    (05/16/2014) With the cooperation of hundreds of ranchers and researchers, Azuero Earth Project aims to replant a swath of tropical dry forest, connecting the dry tropical forest on the coast to cloud forest further inland. The trees along the 140-kilometer (80-mile) wildlife corridor will create a continuous habitat for the Critically Endangered Azuero spider monkey (Ateles geoffroyi azuerensis) and improve the soil for people who farm and ranch along the way.


    Letting forests regrow on cattle pasture yields cheap conservation benefits

    (04/28/2014) Letting forests regrow naturally on grazing lands in the tropics offers substantial climate and biodiversity at a low cost, reports a study published in the journal Nature Climate Change.


    Game of thorns: colorful, spiky tree frog discovered in Vietnam

    (04/25/2014) Evening fog settled quickly on Mount Ngoc Linh, as the steady drone of cicadas and crickets took up their usual nighttime chorus. The night calm was broken by sudden crashing through the thick bamboo stands and excited voices. High in this isolated cloud forest in central Vietnam, researchers had come upon the first thorny tree frog known to science.


    Photos: Weird aquatic lizard discovered in mountain streams of Peru

    (03/13/2014) A 'new' species of lizard has been described from the cloud forests of Peru's Manu National Park, reports SERNANP, the Peruvian National Park Service.


    Amazon trees super-diverse in chemicals

    (03/03/2014) In the Western Amazon—arguably the world's most biodiverse region—scientists have found that not only is the forest super-rich in species, but also in chemicals. Climbing into the canopy of thousands of trees across 19 different forests in the region—from the lowland Amazon to high Andean cloud forests—the researchers sampled chemical signatures from canopy leaves and were surprised by the levels of diversity uncovered.


    Sky islands: exploring East Africa's last frontier

    (12/04/2013) The montane rainforests of East Africa are little-known to the global public. The Amazon and Congo loom much larger in our minds, while the savannas of East Africa remain the iconic ecosystems for the region. However these ancient, biodiverse forests—sitting on the tops of mountains rising from the African savanna—are home to some remarkable species, many found only in a single forest. A team of international scientists—Michele Menegon, Fabio Pupin, and Simon Loader—have made it their mission to document the little-known reptiles and amphibians in these so-called sky islands, many of which are highly imperiled.


    Satellites reveal browning mountain forests

    (11/22/2013) In a dramatic response to global warming, tropical forests in the high elevation areas of five continents have been "browning" since the 1990s. They have been steadily losing foliage, and showing less photosynthetic activity. Scientists analyzed the forest cover by using satellites to measure sunlight bouncing off the surface of the earth, then determining the different surface types via reflection patterns.




CITATION:
Nicholas Barrett (June 24, 2014).

Study finds tiny cloud forests have big biodiversity.

http://news.mongabay.com/2014/0624-barrett-cloudforests-tcs.html