“Shola”的意思、由来-开放百科全书

Shola forests are found in the higher elevation hill regions of the Nilgiris, Anaimalai, Munnar, Palni hills, Meghamalai, Agasthyamalai to the south and the Malnad and associated ranges in parts of Wayanad, Coorg, Baba Budangiri and Kudremukh up the north, in the states of Karnataka, Kerala and Tamil Nadu. Although generally said to occur above 2000 meters above sea level, shola forests can be found at 1600 meters elevation in many hill ranges (e.g. Biligiriranga Hills).

The origin of the shola forest and grassland complex has been the subject of scientific debate. Some early researchers suggested that the floristic composition represents a stable final state or climax vegetation. This stability being maintained by climatic conditions such as frost which allow the grass to grow but kill off any forest seedlings.^[3] Others have suggested that the grassland may have been created and maintained by early pastoralists and point out that fire has a major role in the maintenance of the grassland.^[4] There is evidence for both and several features of the forest trees and the grasslands have been considered and debated. Pollen analysis from bogs in the Nilgiris suggest that the complex of grassland and forest existed 35,000 years ago, long before human impact began.^[5] Long term studies on the dynamic processes of vegetation change continue.^[6]^[7]^[8]

Fauna

Due to their isolation, altitude and evergreen character, shola forests are home to many threatened and endemic species.{{Citation needed|date=February 2011}} Some of the species found here have close relatives only in the distant evergreen forests of Northeast India and Southeast Asia. Some others are found nowhere else in the world.

The Western Ghats are one of the globally recognized biodiversity hotspots. Among the many larger animals inhabiting a shola-grassland mosaic are tigers and leopards, elephants and gaur. The endangered Nilgiri tahr (an Asian goat-antelope) is endemic to the shola-grassland, and its range is now restricted to a 400-km stretch of shola-grassland mosaic, from the Nilgiri Hills to the Agasthyamalai Hills.^[9] Laughingthrushes, Nilgiri woodpigeons, shortwings, and some of the endemic flycatchers (black-and-orange and Nilgiri verditer) are some of the 300+ species of birds that inhabit this area. The area shows high endemicity and is rivalled only by the forests in northeast India; 35 percent of the plants, 42 percent of the fishes, 48 percent of the reptiles, and 75 percent of the amphibians that live in these rain forests are endemic species.^[10]{{Citation needed|date=February 2011}}

Flora

At least 25 types of trees are present in the major sholas of the Nilgiri Hills.^[11] The dominant trees in this type of forest are Michelia niligarica, Bischofia javanica (bishop wood), Calophyllum tomentosa, Cedrela toona (Indian mahogany), Eugenia (myrtle) spp., Ficus glomerata (atti or cluster fig tree or gular fig tree) and Mallotus spp. Shola forests have an upper storey of small trees, generally Pygeum gardneri, Schefflera racemosa, Linociera ramiflora, Syzygium spp., Rhododendron nilgiricum, Mahonia nepalensis, Elaeocarpus recurvatus, Ilex denticulata, Michelia nilagirica, Actinodaphne bourdellonii, and Litsea wightiana. Below the upper story is a low understory and a dense shrub layer. There is a thick concentration of mosses growing on the understory and many ferns in the sunlit narrow transition to grassland.

Shola forests are interspersed with montane grasslands, characterized by frost- and fire-resistant grass species like Chrysopogon zeylanicus, Cymbopogon flexuosus, Arundinella ciliata, Arundinella mesophylla, Arundinella tuberculata, Themeda tremula, and Sehima nervosum.

Threats

Invasive Introduced species are a serious threat to this high altitude ecosystem. Some, like' 'Acacia mearnsii and Eucalyptus globulus are the consequence of commercial plantation and afforestation drives. Other threatening invasives include Lantana camara and Ageratina adenophora.^[12]

Conservation

Periodic fires have been considered to help maintain the grassland, however excessive burning has led to a shrinkage of forest patches and the growth of invasive species.^[13]

The shola biome have a high water retention capacity and exists as the precious source of the water for the high altitude organisms are the origin of many streams and rivers in the Western Ghats.^[11]

Gallery

References

1. ^{{citation |url=http://dsal.uchicago.edu/cgi-bin/romadict.pl?query=சோலை&searchhws=yes&table=fabricius |title= J. P. Fabricius's Tamil and English dictionary. 4th ed., rev. and enl.|author=Fabricius, Johann Philipp|publisher=Evangelical Lutheran Mission Pub. House |year=1972 |page=457 }}
2. ^{{cite journal|title=Phytogeography of the South Indian Hill Stations| author=Meher-Homji VM| journal= Bulletin of the Torrey Botanical Club| volume=94| issue=4| year=1997| pages= 230–242| doi=10.2307/2483901}}
3. ^{{cite journal|author=Ranganathan, C. R. |year= 1938| title= Studies in the ecology of the shola grass-land vegetation of the Nilgiri Plateau| journal= Indian Forester |volume= 64|pages=523–541}}
4. ^{{cite journal|author= Bor, N. L. |year=1938|title= The vegetation of the Nilgiris| journal= Indian Forester|volume=64|pages=600–609}}
5. ^{{cite journal| journal= Géographie physique et Quaternaire| year= 1997| volume= 51| issue= 3|pages=415–426| title=Etude palynologique d'un nouveau sondage dans les marai de Sandynallah (Massif des Nilgiri, Sud-ouest de L'Inde)|author1=Sutra, J-P |author2=R Bonnefille |author3=M. Fontugne |lastauthoramp=yes | url=http://www.erudit.org/revue/gpq/1997/v51/n3/033140ar.pdf| doi=10.7202/033140ar}}
6. ^{{cite journal| title=The montane grasslands of the Western Ghats, India: Community ecology and conservation| author1=Thomas, S. M. Thomas| author2=M. W. Palmer| lastauthoramp=yes| journal=Community Ecology| volume=8| issue=1| pages=67–73| year=2007| doi=10.1556/ComEc.8.2007.1.9| url=http://botany.okstate.edu/people_research/Palmer/Articles/Ghats.pdf| deadurl=yes| archiveurl=https://web.archive.org/web/20110720020622/http://botany.okstate.edu/people_research/Palmer/Articles/Ghats.pdf | archivedate=20 July 2011| df=dmy-all}}
7. ^{{cite journal|author1=Shibu Jose |author2=A. Sreepathy |author3=B. Mohan Kumar |author4=V.K. Venugopal | title= Structural, floristic and edaphic attributes of the grassland-shola forests of Eravikulam in peninsular India| journal= Forest Ecology and Management| volume=65| issue=2&3|pages=279–291 |year=1994| doi= 10.1016/0378-1127(94)90176-7}}
8. ^{{cite journal| chapter= Andisols of the Nilgiri highlands: new insight into their classification, age and genesis|author1=Caner, L |author2=Bourgeon G |lastauthoramp=yes |title=Sahyadri : The Great Escarpment of the Indian Subcontinent (Patterns of Landscape Development in the Western Ghats)|editors=Y. Gunnell and B.P. Radhakrishna. Memoirs Geological Society of India, Bangalore, 2001, No. 47|year=2001|publisher=Geological Society of India|pages=905–918.|url=http://hal.cirad.fr/docs/00/25/94/35/PDF/Caner_Memoir-Geological-Society-India_2001.pdf}}
9. ^Misra & Johnsingh 1998
10. ^Govt. of India 1997
11. ^¹Premalatha S., Sanil R. & Franklin Charles Jose. 2009. Shola trees in the upper Nilgiris of Western Ghats. Journal of Basic & Applied Biology 3(3&4),97-102.
12. ^{{citation|url=http://www.akademiai.com/content/w7613053k523056r/fulltext.pdf|title= The montane grasslands of the Western Ghats, India: Community ecology and conservation|work=Community Ecology|author1=S. M. Thomas |author2=M. W. Palmer |lastauthoramp=yes |publisher=Akademia Kiado, Budapest|year=2007|page=8(1): 67–73|accessdate=20 July 2016}}
13. ^Rawat, G.S, P.V. Karunakaran, and V.K Uniyal. 2003. Shola grasslands of the Western Ghats: conservation status and management needs. ENVIS Bulletin on Grassland Ecosystems and Agroforestry 1(1):57-64. 112 kB PDF {{webarchive|url=https://web.archive.org/web/20050302152745/http://envis.iifm.ac.in/EB/Sholagrass.pdf |date=2 March 2005 }}