The creeping pine question reloaded

Is climate change raising the treeline in Japan ’s Southern Alps and driving the creeping pine into retreat? Somebody should go and take a look at Tekari-dake (日本語要約は下にあります）



Are forest trees invading the summit of Tekari-dake (2,591 metres), the last high mountain in Japan ’s Southern Alps ? And is the creeping pine, the alpine shrub that previously covered the summit, now retreating? After a previous post raised these questions, some new photos* clearly show that tall trees surround Tekari's summit marker. Half a century ago, the Hyakumeizan author Fukada Kyūya describes the area as the southernmost point in Japan – or, indeed, Asia and the world – where creeping pine (haimatsu, Pinus pumila) grows.

So, what is happening on Tekari? To answer that question, somebody needs to go and take a close look at the summit. What is the extent of the forest trees and where did they come from? Maybe the staff of the nearby Tekari hut can shed light on those questions – do they remember when the forest trees appeared? Or have they always been there? Is there any creeping pine left? And where along the ridgeline does the forest stop and the creeping pine begin? It would help also to find a photo of Tekari’s summit in Fukada’s day. Fukada mentions in Hyakumeizan that his companion, a botanist, took such a photo. Maybe other photos exist.

Why does the creeping pine question matter? Well, it might just be an early sign of a rising tree line in the Japanese mountains. That would be significant, given that vegetation zones are expected to rise – and indeed are rising – as the climate warms up. Creeping pine won’t be the only loser, by the way. Japan ’s temperature-sensitive beech forests are also expected to retreat. Isolated pockets of beech, like the one in the Amagi mountains, will presumably die out.*

Might it be that Tekari is the front line in this ecological upheaval? It is too soon to leap to conclusions. Even if the forest trees can be proved to have replaced the creeping pine, the mechanism might not be global warming but something local – the haimatsu may have succumbed to a forest fire or the erosive feet of Hyakumeizan-baggers, for example. That said, the few scraps of evidence on hand are suggestive. “Thus it was that Tekari became a mountain of botanical significance,” says Fukada Kyuya in Nihon Hyakumeizan. Now it is again, and more than ever before.

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日本語要約

光岳のハイマツ問題 - 地球温暖化の前兆か

深田久弥の日本百名山は昭和39年（1964年）に刊行された。深田久弥が南アルプスの最南端である光岳を訪ねた時、頂上は典型的な高山植物であるハイマツに覆われていたという。このハイマツは、結局、日本だけでなく、世界最南端のハイマツであるとのことだった。しかし、現在となって、光岳の頂上にハイマツはほぼあるいは全く見られなくなった。その代わりに、頂上付近は普通の森林樹木に覆われている。これは地球温暖化のせいか、それともほかのメカニズムがもたらしたものなのか。"国破れて山河在り" と中国の杜甫は詠ったが、地球温暖化の時代に入ると、山河も破れる恐れあり、か．．．

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References

Nihon Hyakumeizan in a forthcoming translation as “One Hundred Mountains of Japan”

*in Saishinpan Nihon Hyakumeizan, Asahi Visual Series, 2008 May 18 edition, No.16, Hijiri/Tekari (Many thanks, Kawamata-sensei!)

The Potential Effects of Climate Change in Japan, Center for Global Environmental Research, National Institute for Environmental Studies, Environmental Agency of Japan – see Chapter 3: Climate Changes and Forests

Ecological Status of Pinus Pumila Scrub and the Lower Boundary of the Japanese Alpine Zone by Osamu Yanagimachi, Hosei University, and Hiroo Ohmori, University of Tokyo, paper in Arctic and Alpine Research, Vol 23, No.4, 1991 – establishes the lower and upper limits of creeping pine as temperature-sensitive.