I have a question. My grandfather says that during Japanese rule of Korea, we planted more than 600 million trees, helped teach them farming techniques to prevent soil erosion, and revived the ecology of many barren mountains. I've read that this is true in various history books, too.
But I also speak Korean now and I've recently found out that many Korean books say that Japanese military deforested the mountains through industry and Korea revived them after being independent. I've just looked on the internet for English sources, but all I've found are Korean accounts that support this interpretation.
Did Korea used to have many barren mountains? If so, was it Japanese policy during the colonial period that made them lush as they are now? Or was it the opposite?
There was a reforestation program on pre-1905 damage, and this was a propaganda point for Japan, but subsequently Japan seized a large portion of forest land and invested in harvesting timber from it.
By the time of liberation, the stock volume (of wood per hectare) was about a third of its 1910 level, so it's hard to argue that reforestation had any effect.
Edit: Sources (sorry short on time as well.)
http://www.fao.org/docrep/003/w5547e/W5547E02.htm
It looks like the reforestation was concentrated around the cities, while the timber harvesting was farther inland, so it was easy to think that forests had been restored all over.
So I've looked at some of the numbers here, and ultimately I would not be satisfied with the answers I see here, which basically amount to "Japan set up a forest agency to steal land from Korea and export wood to the main island." While it is clear that the Japanese certainly economically exploited their colonial territories, there's a bit more nuance than having the Japanese simply shipping millions of tonnes of timber back to Japan. In fact, the US Forestry Service considered such exports to be relatively insignificant at best.
Most of the lumber harvested in Korea and Manchuria was primarily used for industrialization and construction within Korea and Manchuria. A key point to remember is that the Japanese at no point envisioned ever losing control of Manchuria or Korea, and took steps-such as massive military garrisons-to make sure this was the case. This resulted in the construction of barracks, homes for the increasing population (both Japanese immigrants as well as a rapidly expanding Korean population), factories, and most importantly infrastructure, so that the Japanese Empire could, if needed, move troops around quickly, supply them with arms and ammunition, and take advantage of cheap Korean labor in the process. Railway track (which certainly requires lots of wood) in Korea, for instance, increased by a factor of 6 in the roughly 40 years of Japanese control of Korea.
When it came to Japanese forestry policies, the Japanese certainly did establish a forestry service in Korea and its other colonies, in the pattern of the domestic one. However, the domestic one was much better run, funded, and also actually enforced. A significant amount of illegal logging was occurring in Korea, both by the large Japanese-owned companies that dominated the Korean lumber market, as well as by locals who may have been unable to afford firewood due to low wages. The US Forestry Service estimated that while around 41 million cubic feet per year were harvested between 1920-1935, primarily in northern Korea near the Yalu River, much more-300 million cubic feet, or more-was unreported and being used possibly for firewood. By 1940, this number was likely ~500 million cubic feet between Korea and Manchuria. Indeed, the demand for lumber in Korea between domestic consumption and Japanese military needs had risen such that domestic Japanese lumber was being exported to Korea around the time of the Second Sino-Japanese War in 1937.
Unfortunately, given that our only knowledge of the state of the main Korean lumber supply-the Yalu River basin-would come from the forestry service of the Democratic People's Republic of Korea (assuming they would even publish a fair figure), I would be highly hesitant to rely on any hard numbers regarding overall reforestation or deforestation.
On a bus so i cant really put sources till later but, i would like to weigh in. Japan's claim on introducing land reform is somewhat true but this didn't really help to revive the ecology of the Korean peninsula. To put it in layman's term, the land reform basically was a way to exchange ownership of the land. They stripped the korean ruling class (yangban.. kinda like nobles) of their land into japanese agricultural corporations. It had very little ecological impact and impoverished many Koreans due to high taxes on the tenants.
If they did have any positive impact on the ecology of Korean peninsula, it was probably nullified by the ensuing Korean war after WW2. In roughly 3 years, the war took a huge toll on the land due to heavy bombings and artillery fire across much of the korean peninsula. it wasn't that uncommon to see mountains completely devoid of any large vegetation. Any kind of large scale farming also stopped during this time.
Bombing runs and artillary fire to devastate mountains played a huge roll in the war due to the fact that the terrain of Korean countryside were very mountainous. In extreme cases large mountains were reduced to small hillls due to constant exchange of occupation through out the war. They reforestation campaigns came after the war.
On another note, Japan treated their annexed lands and its citizens very poorly and used the resources of their annexed lands to enrich their main island. i could go into details but im almost at my stop. if you have any questions, you can send me a pm and i will answer them best i can. I could probably point you to many useful sources as well =] (assuming you have access to JSTOR)