Thursday, 15 August 2013

Langkawi Geopark

Langkawi comprises a group of 99 tropical islands laying of the northwestern coast of Peninsular Malaysia.   With a geological history dating back 550 million years, the islands contain unique rock formations, which earn itself UNESCO’s Global Geopark status on June 1st, 2007.


Langkawi was born in the Cambrian era as a broad sedimentary mound, as part of the Gondwanaland supercontinent,  at the bottom of a turbulent sea just north of the equator.  Tectonic plate movements carried the mound south to the cold Antarctic regions.  The frozen glacier crushed the limestone, sandstone and siltstone into a base of hard granite and marble.  Then, over 400 million years, it was covered by deposits of various material from sea life skeletons to glacial droppings.

During the Permian period, the plate broke away and moved northward back to the equator.  In a series of cataclysmic event accompanied by exploding volcanoes and hot lava, the plate crashed up against the East Malaysia/Indochina block, which pushed the whole block all the way to the surface to form the Malay Peninsular.  The cataclysmic events also pushed the Himalayas to the roof of the world.

Large mound of rock and limestone then form small group of islands off the coast of the Malay Peninsular.   One mount of hot magma eventually squirmed up some 800 meters to form the Gunung Raya.  At about the same time, an ancient limestone mountain rose from the sea to form Gunung Machinchang.

During the Jurassic period, the land is further carved by the erosions, chemical reactions and a series of uplifting eruptions.

Later during the last Ice Age, sea levels were pushed up and down drastically as a result of glacial melting and global cooling, forming caves full of fossils.

Langkawi Geopark

Langkawi Geopark comprises of Machinchang Cambrian Geoforest Park ( 4,274 ha ), Kilim Karst Geoforest Park (8,261 ha ), and Dayang Bunting Marble Geoforest Park ( 4,354 ha ). 

The Machinchang Cambrian Geoforest Park

Machinchang Cambrian Geoforest Park hosts the oldest geological formation in Malaysia known as the Machinchang Formation ; oldest grains of sand at Teluk Datai ; oldest fossil on Pulau Jemuruk. ; and Tanjung Sabung where limestone succeeds sandstone. 
Other attractions within the park include : Telaga Tujuh waterfall,  beautiful beaches in Teluk Datai and Pantai Kok.

Kilim Karst Geoforest Park

Kilim Karst Geoforst Park features magnificent landscape of limestone pinnacles of various shape and sizes.  The northeastern region encompassing three river basins of Kilim, Air Hangat and Kisap too host magnificent landscape of mudflats, beaches, mangroves and caves.  The name ‘Langkawi’ is said to have been derived from the Brahminy Kite eagle, which is the dominant faunal species of the area.

The Dayang Bunting Marble Geoforest Park

The Dayang Bunting Marble Geoforest Park is made of Permian marble overthrusted by older Setul Formation limestone.    One of the most unique features of the park is the fresh water lake of Tasik Dayang Bunting, formerly a dry doline resulted from the collapse of a very large underground limestone cave.

Other geological marvels

An alien granite dropstone that is 1 billionyears old can be founding sandstone and mudstone at Pulau Tepor.  These dropstones once drifted by a glacier before it was dropped in Langkawi which was still submerge underwater.

An ancient seabed also can be found in Pulau Ular.

A cater known as Mahsuri Ring is said to be the result of the impact of a meteor .  The crater lay in the alluvium paddy field, is visible from Gunung Raya.

Friday, 2 August 2013

Momordica dioica - Kakrol

Kakrol is most probably the fruit of Momordica dioica, a liana of the gourd family, Cucurbitaceae.   Kankrol is also known as spiny gourd, teasle gourd.  

In South Asia, where kakrol is widely cultivated for consumption, it is known in many names : karela (Hindi), katwal (Gujarati), erimapasel (Malayalam), karkotaki (Sanskrit), palu-pakal (Tamil), advikakara (Telugu), bhat korola (Bengali),  etc.

A kakrol fruit is oblong, about 6cm in length and 3cm in diameter, turned yellow upon ripening, with surface covered in many small soft blunt pines. 

Kakrol fruits is bitter in taste.  They are usually peeled before cooking.  They are usually cook with curry, or hollowed, stuffed with spices and steamed, or made into pickle, etc.  

Thursday, 1 August 2013

Salvinia minima - Common Salvinia

Salvinia minima is a species of aquatic, floating fern of Salviniaceae family native to South America. 

The leaves of S. minima are small and oval, ranging from 0.4 to 2.0 cm in length.  The leaves grow in sets of three, with two leaves floating on the surface and one leaf dissected, hanging underneath.  Fine white hair grow uniformly on the leaf surface.  Brown hairs present on the underside of leaves.  S. minima is rootless.
Salvinia minima is classified as an invasive species on the Global Invasive Species Database.  It can be a nuisance to recreational watercraft, have adverse affects on fish farming, rice farming, and poses a serious threat to native species and biodiversity.
Salvinia minima grows on the surface of still freshwater.  Although it is sterile, S. minima can reproduce quickly very quickly asexually through fragmentation.  Buds and rhizome fragments can also remain dormant for long period of time when growth is less favorable.

S. minima undergoes 3 stages of growth.  In the primary stage, the leaves will lie flat on the water surface.  In the secondary stage, the leaves multiply and curl upward.  In the tertiary stage, the leaves become more dense and almost vertical due of crowding.

S. minima can easily out-compete and inhibit the growth of native water plants.  Mats of S. minima can block sunlight from entering the water.  S. minima, which has no nutritional value, is not favoured by fish or bird species as a food source.

In order to protect native ecosystems, numerous effort have been taken to control or eradicate the growth of Salvinia minima.   Herbicides that have been used with best success include : fluridone, imazamoz, and penoxsulam.  Successful biological control agent includes Crytobagous salviniae,  the salvinia weevil native to South America ; and Samea multiplicalis, the salvinia stem-borer moth native to southern US.