Madagascar Subhumid Forests and Ericoid Thickets

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Known to be a "living laboratory" for its isolation from other large landmasses for 150-180 million years, Madagascar created diverse ecosystems to provide a home for a rich variety of unique plants and species, like the Madagascar Subhumid Forest and Ericoid Thickets. Madagascar's forests and shrublands are located on the eastern and northern part of the island, spanning about 313,000 square kilometers (121,000 sq. miles).

Madagascar Subhumid Forests:

Madagascar Subhumid Forest
http://www.flickr.com/photos/56601430@N05/5257358515/

Madagascar Subhumid Forests span about 199,500 square kilometers (77,000 sq. miles) and occupy most of the montane humid forests throughout the central highlands. Before, the subhumid forest genuinely covered most of the central highlands at about 800 meters elevation in the east and 600 meters elevation in the west, intersecting with the lowland forests and the dry deciduous forests. Once the elevation went above 1,800 meter elevation, the subhumid intersected with ericoid thickets. Subhumid forests were known to be a part of the endemic regional center in the eastern part of Madagascar. The central highlands was the home to a great amount of endemic plants and species, like the elephant bird, aepyornis maximus (largest bird species ever), giant tortoise, and large sized lemurs.

Amber Mountain (Montagne D'Ambre)
http://www.travel2madagascar.com/typo3temp/pics/fb6abdc165.jpg

Amber Mountain (Montagne D'Ambre) is known to have an abundant area of subhumid forests, while also being surrounded by dry deciduous forests. On the slopes of Amber Mountain, the subhumid forests carry 40 m. tall canopies with amounts of family plants and high in diversity of animals, 8 primate species and 80 bird species, like the endemic Amber Mountain Rock Thrush. 

Amber Mountain Rock Thrush
http://img.burrard-lucas.com/madagascar/full/amber_mountain_rock_thrush.jpg

Human Impacts:

Rice fields in Madagascar's central highlands
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Many of the natural vegetation disappeared as small patches of those have been called as biodiversity "jewels". Since 2,000 years ago,as humans arrived for the first time, more than 90% of its natural cover and endemic species became extinct. With the increasing human population, agriculture, and fire, many conditions of the subhumid forests in the central highlands deteriorated. Significant areas, like the wetlands, were cleared for rice cultivation. As the runoff from the agriculture polluted the wetlands, many species began to become extinct. For example, Lake Alaotra had the Alaotra little grebe, Madagascar pochard, and Alaotra gentle lemur but became endemic species, due to the rice cultivation. Aside from rice cultivation, native people extensively used the slash-and-burn agriculture, since 1970, and firewood collection, harming the forest's environment and native species. With the repeated use of slash-and-burn, the nutrients in the soil disappear, leading to an unproductive condition. Even today, all the distinct ecosystems and its species face various threats, leading Madagascar to have the most critical and endangered species and plants. 

Map of human induced soil degradation and erosion in Madagascar
http://www.wildmadagascar.org/maps/erosion.html

Future Prospects:

Based on the current human impacts, the recovery for Madagascar subhumid forests has a low chance of recovery. Right now, the status is very critical, as many endemic species are becoming more extinct. Even if people were to stop all actions that could harm the ecosystem, it would still take a long time for the environment to fully restore back to the way it was. Although, there are several conserved and protected areas of subhumid forests in parts of Madagascar, there are still many areas that are being threatened. Fortunately, local communities and the government are working together with organizations and groups, like the Wildlife Conservation Society (WCS) and Fanamby, to expand the protection system of the ecosystem. 

Map of conservation areas
http://www.wildmadagascar.org/maps/conservation.html

What can be done to improve:

By acknowledging the current status and threats of Madagascar subhumid forests to people, it would help acknowledge that Madagascar is in great need of help of conserving the area. If the acknowledgment is spread throughout society, it could convince the government to ban threats, like slash-and-burn agriculture, from areas that have not yet been jeopardized. Creating more conserved areas and national parks would benefit the ecoregion from being threatened and destroyed. If people supported the creation of national parks in unprotected areas of the subhumid forests, then not only would it help preserve the ecoregion, but it would also give an opportunity to let people see and experience the beauty of Madagascar subumid forests. 


Madagascar Ericoid Thickets:

Marojejy Massif
http://www.eoearth.org/images/183105/500x0/scale/Massif_Marojejy.jpg

Once the elevations for the subhumid forests go higher above 1,800-2,000 meters of elevation, ericoid thickets replace the ecoregion. Madagascar Ericoid Thickets are located on the slopes of Madagascar's four mountain massifs: Tsaratanana (2,876 m), Marojejy (2,133 m.), Ankaratra (2,643 m.), and Andringitra (2,658 m.). The ericoid thickets spans about 500 square miles, as it has only been a recent scientific discovery. Although there is still a lot more to be discovered, the ericoid thickets have similar numbers of endemic species and yet to find further more. There is a common temperature change in the ericoid thickets, as the temperature ranges from -11°C(lowest)  to 30°C(highest). 

Orchid from Andringitra National Park
http://www.travel2madagascar.com/uploads/pics/Orchid.JPG

The ericoid thicket has more than 10 species of endemic reptiles, like gecko, Millotisaurus mirabilis, and Lygodactylus arnoulti. Recently, Andringitra has been discovered with new endemic species, Gekkonidae and Lygodactylus montanus. Five other species, along with one amphibian, Boophis williamsi, are considered to be nearly endemic to the habitat. Although there are many endemic species, they belong to a widespread genera. Ericoid thickets also have a remarkable amount of endemic plants and plant families like Asteraceae (Psiadia, helichrysum, Stoebe, Stenocline), Ericaceae (Erica, Agauria, Vaccinum), Podocarpaceae (Podocarpus), Rhamnaceae (Phylica), and Rubiaceae. The name, ericoid thickets, was adopted for having thicket-forming plants from one of its plants species: the Ericaceae family. Many ericoid thickets support plants that are able to survive with less water, like Aloe, Kalanchoe, and Helichrysym. The habitat has remarkable flora with numerous endemic species. For example, the Andringitra massif has over 150 vascular endemics and 25 species of orchids. 

Boophis williamsi
http://calphotos.berkeley.edu/imgs/128x192/1111_1111/1111/8169.jpeg

Human Impacts:

Fire set for cattle grazing
http://photos.wildmadagascar.org/images/pictures/madagascar_6918.shtml

Currently, ericoid thickets have lost its natural vegetation, due to the use of cattle pasture. In order to create the pastures, people create fire to prevent the young grasses from growing. Sometimes, fires can also occur from natural disasters, like lightning strikes. Fire is considered to be the biggest threat for the ericoid thickets. Especially in Tsaratanan and Ankaratra, many natural habitats decreased, as people used these places for burning. The people use the burnt areas and convert those to areas of highland cattle pasture, as it has already occurred on the Plateau d'Andohariana (Andringitra Massif).  Although ericoid thickets are somehow protected by the lower altitudes from the forests, the increase of domestic animals still threaten the ericoid thickets. To make matters worse, the excrement from the domestic animals have seeds that introduce new plants to ericoid thickets. The Ankarata massif has small areas of unauthorized protection in the native forest, like the Manjakatompo Forest Station of 6.5 km. squared. The ericoid thicket's high elevation patches are broken down because of the scattered locations of the mountain massifs in Madagascar. 


Future Prospects:

Madagascar National Parks 
http://thumbs.dreamstime.com/thumblarge_608/1306690311a207zB.jpg

The future for Madagascar ericoid thickets looks positive, as three of the four massifs: Tsaratanana, Andrigitra, and Marojejy, are being protected and conserved as national parks. The protected three mountain massifs span about 171 km.squared. In particular, the Andrigitra and Morjejy massifs are known to be best preserved and protected from threats. In 1995, a workshop, regarding to the concerns of the threatened areas, was held to talk about preserving the ecosystems that are in high elevations, undiscovered ecosystems, and water quality. Through the workshop, the Aknaratra massif was recognized to be an important place of high biodiversity. 

Andringitra National Park
http://www.flickr.com/photos/rowe_becky/4654369474/in/photostream/

What can be done to improve:
If people still continue to conserve the three remaining massifs, the ericoid thickets could still have its natural vegetation. National parks can help preserve the ecoregion and have strict rules in order to protect the ericoid thickets from being threatened or destroyed. However, with the remaining massif, Ankaratra, if people spread the acknowledgement of the current status of the massif, it would convince people to stop the burning of the ericoid thicket's vegetation. It is important for people to recognize the problems in the ecoregions and help create National Parks in unaffected areas to prevent fires for pastures. If the problem was recognized, then the government could also help by taking action and preventing the people, who create cattle pasture, from using and harming the ericoid thickets.




References:
1) Crowley, Helen. "Madagascar." Wildlife Conservation, Endangered Species
            Conservation. World Wildlife Fund, n.d. Web. 23 Nov.2012.
            <http://worldwildlife.org/ecoregions/at1011>.

2) Crowley, Helen. "Southern Africa: Central Madagascar." Wildlife Conservation,
             Endangered Species Conservation. World Wildlife Fund, n.d. Web. 23 Nov 2012.
             <http://worldwildlife.org/ecoregions/at0118>.

3) "Global Species : Ecoregion : Madagascar Ericoid Thickets." Global Species : 
             Ecoregion : Madagascar Ericoid Thickets. Myers Enterprise, n.d. Web. 23 Nov. 
             2012. <http://www.globalspecies.org/ecoregions/display/AT1011>.

4) "Global Species : Ecoregion : Madagascar Subhumid Forests." Global Species :
             Ecoregion : Madagascar Subhumid Forests. Myers Enterprise, n.d. Web. 23 Nov.
             2012. <http://www.globalspecies.org/ecoregions/display/AT0118>.

5) "Madagascar Ericoid Thickets." Madagascar Ericoid Thickets. Ed. Mark McGinley.
             Environmental Information Coalition and National Council for Science and the 
             Environment, 21 Aug. 2008. Web. 23 Nov 2012.
             <http://www.eoearth.org/article/Madagascar_ericoid_thickets>.

6) "Madagascar Forests and Shrublands - A Global Ecoregion. WWF. N.p., n.d. Web. 23
             Nov. 2012.
            <http://wwf.panda.org/about_our_earth/ecoregions/madagascar_forests.cfm>.

7) "Madagascar Subhumid Forests." Madagascar Subhumid Forests. Ed. Cutler 
             Cleveland. Environmental Information Coalition and National Council for Science
             and the Environment, 27 Oct. 2006. Web. 23 Nov. 2012.
             <http://www.eoearth.org/article/Madagascar_subhumid_forests>.