Pang Soong Lodge Field Centre

We have been having some unusual weather as cold snap hit Chiang Mai at the end of March, in the city market places people were fleece and balaclava clad in the middle of the day. Bangkok had been it by cold season, hot season and monsoon conditions in the space of a week. The cold snap was due to a low pressures cell over the area, bringing cold weather from the North. Combined with an earthquake hitting the city and triggering a landslip on the path up to the Huay Hom waterfall conditions seem far from normal.

At this time of year it is normal to experience very hot dry conditions, with temperatures of over 40 degrees, combined with poor visibility from low air quality. During March the clear skies of February are replaced by haze. Earlier on in the year we were enjoying clear views down the Mae Lai valley back to Chiang Mai city from the ridge walk. The reduced visibility can be seen in this image from April 2010:

The lost city of Chiang Mai is on the horizon in this image

The air quality issues come from particulate pollution, normally measured as PM10, or particulate matter on ten microns in diameter. In Thailand the Pollution Control Department sets guidelines of 120 micrograms per metre cubed as a safe limit, although the World Health Organisation sets an even safety limit of 90 micrograms per metre. Above these guidelines schools do not let children play outside and it is recommended that masks are worn. Air quality has impacted on the lichen communities (Saipunkaew, Wolseley, Chimonides, & Boonpragob, 2007) and, as well as being
a significant human health issue, this will also have an effect on other species of animal. Chiang Mai’s records show that the safety level was exceeded 17 times in March and April 2010 and 16 times in 2009. The records also show that this pollution is higher than that recorded at the same time in Din Daeng, Bangkok’s most polluted air quality monitoring station. However throughout the year the Bangkok readings record more in total, with records worst in the cold season. For 2011 however the air quality has not gone over the standard at all, we can breathe easily!

The reasons behind these differences are to do with location and pollution sources. In Bangkok the cold season brings temperature inversions and the pollution is generated from within the city and then locked down. It comes from a variety of sources such as dust from construction and charcoal burning from street vendors, as well as two-stroke and diesel engines. A quick look at the pollution development departments website shows the cold season peak in particulates for Bangkok and not a hot season peak. Outside of the city, or the Lampang coal-fired power station, the hot season peak in particulates is due mostly to forest fires and other burning in fields or houses.

Fire on the ridge above the Pok-a-long stream

• Allow easy access for hunting
• Clear land for planting of subsistence or cash crops
• Encourage growth of wild mushrooms (against the scientific evidence)
• Show power and imply ownership of territory
• Return nutrients to the soil (against the scientific evidence)

The Mae Lai valley is not generally burned and in the valley base fires are rare. But up on the ridge fires are started and logs deliberately rolled down slopes to spread them. This picture shows burning on the ridge around a tree fern Brainea last year, fortunately these beautiful and unusual plants seem to recover well. This year the fires seem less widespread in the Mae Lai forests.

Burnt Brainea

An old friend was in town and he asked if he could visit the lodge. I couldn’t think of a better way to shake of the over-indulgence of the festive season than taking a good long walk in the forest at Pang Soong. So we went up on New Year’s Day, and along with our guide started off along the trail that follows up the Mae Lai valley. I was particularly interested in the rocks in this area as the geology has intrigued me for some time now.  Essentially the geology of the rocks under the whole of the community forest are triassic granites, but there are patches of some rocks which could be considerably older. The triassic granites date back 220 million years or so, according to measurements based on strontium isotype ratios, this massive of granite termed the Doi Saket- Wiang Pa Pao block is around 215 million years old. This would date them to around the start of the dinosaur era from Thailand’s Issarn region, and twice as old as the granites of Phuket and Phang Nga.

Granites are intrusive igneous rocks, essentially formed from huge bubbles of molten magma that rise up from the mantle pushing up through the local rocks eventually cooling in a variety of massive structures. One consequence of granitic cooling is that the surrounding rocks are cooked, producing a variety of metamorphic rocks and mineral deposits. Ore rocks such as cassiterite or tin ore is often produced and these have been mined historically on the mountain above Pang Soong – Doi Lohn. Tin deposits are either mined from the original rocks or from more recent sedimentary deposition. Harder and older metamorphic rocks are likely to be found on the edge of the granite or above in a region called the metamorphic aureole. Here at Pang Soong there are sandstones that may have some metamorphosis and could fit into an older carboniferous rock sequence, in other words over 300 million years ago. At this time the major land mass here was along the southern shore of a massive E-W ocean called Tethys. There is also a rock found at the base of the Mae Hawn waterfall that appears to have secondary deposition and could be a tuff.  It appears to be secondary limestone deposition, but no acid reaction was seen on the specimen I have. For me the jury is still out on the identity of this one.

Leaving the chinese gorge

We headed up from the Mae Lai valley following the course of Huay Tham, the cave stream. There are spectacular waterfalls on this route, including one that is around 30m high, Namtok Huay Tham seen in the picture above. Here we stopped for lunch before continuing to explore higher up stream and to find a cave I had heard about. To get there we had to climb up onto the ridge and then back down above the Huay Tham waterfall. The path hadn’t been walked here for a while and took quite a bit of  clearing before we came up against a massive wall of rock. A massive piece of granite over 20 metres high and continuing on into the jungle. Our resident local guide and forest expert, Khun Yuern explained that this was the community forest’s own “kampaeng jin”, or Chinese Wall. We followed the wall for some time until another one rose up and we were following through a narrow gorge up to the cave with the stream rising up and disappearing down into the loose boulders beneath our feet.

Mineral deposits and veins in the cave

The cave itself was perched a few metres up on the side of the great wall gorge, a short scoop out of the granite only ten metres or so deep. The rocks were covered inside with nodules and veins, some green telltale signs of copper and the rusty red of iron. I wondered how it had formed. An unusual feature for water erosion alone, and given it appeared to be mineral rich I wondered if this could have been an old working, perhaps very old. Khun Yuern said that it had never been worked and was a natural formation. Although he had heard local stories about giants in the past, and it is easy to see how these arose to answer some of the questions about the rock formations.

According to Khun Yuern this used to be roost for bigger bats, from his description they were flying foxes, but there was only a small bat roosting high up in the cave. Apparently the big bats have been hunted and eaten, the fate of much of the regions biodiversity. Although on the way out we came across a rather large horseshoe bat, in an overhang. According to the Boonsong’s Mammals of Thailand this looks like the largest of the Thai horseshoe bats.

Rhiolophus luctus, Greater Eastern Horseshoe Bat

The new year also marks a new beginning for the Pang Soong Lodge Field Centre, with so many developments in progress that I will return to them in later posts. But for a start to this blog I thought it would be interesting to consider what makes Pang Soong such a special place and why so many who visit the lodge want to return. Perhaps this is easiest done through the notion of a sense of place in relation to Pang Soong and the Mae Lai valley.

Sense of place itself is a term widely used to really give over an impression of a local identity shown by the relationships developed between people and their environment. It is difficult to put your finger on what this sense really is, a something that is not found in data or maps, but more in the impressions, emotions and perceptions of people when they travel to some of the planet’s more special places. It is a tricky expression to pin down, and the significance of the term is probably best understood by considering almost its polar opposite. The “placeless” places that have mushroomed in the rapid development of the second half of the 20th century and continue into the 21st. The urban sprawl and shopping malls of  cities such as Bangkok, Singapore and Hong Kong. Increasingly these places have no sense of place simply because they can exist anywhere. By contrast there is no forging of a relationship between people and the environment. The substrate is flattened or eroded, the climate conditioned to our desires and the globally ubiquitous brand names and shops styles brought in. Identity of places that existed in the past in the capital city of Bangkok are easy to find. The city’s name itself derives from the place or village of the cherry tree, don makok. This is commonly called a Hog Plum, Spondias dulcis a tree that is now far more commonly found  in these Northern Hills than it is down in the Bangkok flood plains. Other places now in the Bangkok suburubs also indicate the sense of place that used to exist before the concrete; Bang Plee – Banana Flower Place, Bang Kapi – Shrimp Paste Place and Bang Na – Paddy Field Place.

Up in Pang Soong it is harder to consider a greater contrast to the central shopping areas of Asia’s cities. The word “Pang” itself is a Northern Thai word (Kham Muang), meaning place. “Soong” itself means high in standard lowland Thai. So the name Pang Soong lends itself to the title of this blog, and within the country as a whole this land area above 1000m covers less than 5% of the land area.  The forest here at Pang Soong is typical of this kind of altitude, an evergreen hill rainforest. Deep soils have developed over the rotted triassic granite bedrock beneath, the product of chemical weathering on the feldspars in the rocks producing a looser material called growan. This develops a distinctive and clear soil horizon pattern that is reminiscent to me of forests I have known well in Devon with the same iron rust red colouration present in the mineral layers. Above ground other features are also reminiscent of temperate forests, the plant community is dominated by the family Fagaceae a.k.a. Oaks and Beeches, in far greater diversity than that found in Europe. Here there are Castanopsis, Quercus, Lithocarpus, and a rare genus Trigonobalanus found. Given the similar architecture of these trees the impression would be of a temperate deciduous forest, were it not for the strands of lianas such as Mucuna macrocarpa tangling around the trees. These lianas are often the oldest residents of a disturbed forest, revealing a rich history of tree fall and fire. Ghosts of trunks and canopies from times gone are hinted at by the loops and twists of their boughs.

Many travellers, driving up the Mae Lai valley for the first time comment on the landscape and architecture. The steep-sided valley hosts numerous small hamlets, clusters of stilted wooden buildings in traditional Khon Muang style, with galare trimmings to the eaves and ridges. Combined with the cool microclimate many comment that it has a feel more like a part of Europe than Thailand. At Pang Soong Lodge temperatures are often a full ten degrees lower than the lowland equivalent, and in the hot seasons it is a particularly cool retreat. This European feel is an illusion of course, and a stop in to one of the hamlets will confirm that this really is Northern Thailand by any measure. One more peculiarity of this place though, is that this is a rather high settlement by Thai standards as there are no other ethnic groups in the valley. In many other regions the Thai villages give way at mid altitudes to Karen hilltribes, and at higher altitudes to groups such as Hmong or Akha. Again this has lent itself to a particular approach to managing the forest which has been traditionally a community forest managed for the growing of “miang”. This is a native green tea, Camellia sinensis, the leaves of which are fermented and used for chewing. This practice has allowed much of the forest to remain comparatively intact compared with many similar areas in the North and further lends itself to the rather exclusive identity of this high place.