Logging erosion
From: Vsg <vsg-bounces@mailman11.u.washington.edu> On Behalf Of Chuck Searcy
Sent: Thursday, April 1, 2021 9:27 PM
To: Greg Nagle <gnagle2000@gmail.com>
Cc: Vietnam Studies Group <vsg@u.washington.edu>
Subject: Re: [Vsg] Road and logging erosion in A Luoi district, Thừa Thiên Huế province in Central Vietnam
Greg, your photos show more damage than I recall when I traveled on this road in 1995 (or 1996, I'm not sure) with the Hatfield team. The driver, in his mid- or late-30s, said that as a boy he remembered these hills with jungle foliage so thick that it felt like dusk, with little light penetrating. He said he saw monkeys and other wild animals, and once he encountered a tiger. The erosion I saw was more patchy, less pervasive than in your photos, and the hills were mostly green with scrub vegetation though noticeably lacking any large or obviously mature trees, which I assumed would eventually come back, over time. The driver blamed the landscape on Agent Orange, even then. He attributed little of the environmental damage to bombing. Your photos, however, rather than showing further recovery over the years, appear to depict further deterioration. That is not encouraging.
I would like to see your more detailed report.
Chuck Searcy
From: Vsg <vsg-bounces@mailman11.u.washington.edu> On Behalf Of Greg Nagle
Sent: Wednesday, April 7, 2021 10:04 AM
To: George Black <ghsblack@gmail.com>
Cc: Vietnam Studies Group <vsg@u.washington.edu>
Subject: Re: [Vsg] Road and logging erosion in A Luoi district, in Central Vietnam
They can actually harvest it at 3 years ,but most often about 5,
Advantage of younger harvest is faster income and it is small enough to mostly do it by hand on many slopes,
There are about 2.5 million hectares of acacia, probably more now, Wood products are now a major export. exported mostly for chips. Older trees can be used to make veneer or for furniture , Acacia can be planted on degraded, nutrient poor lands, it fixes nitrogen so it grows well,
On the other hand, too much nitrogen can acidify the soil which immobilizes some soil phosphorus which is the critical limiting nutrient for long term sustainability,
Much acacia is grown by small landowners,
The pictures you saw were from some of the steepest, most erosive slopes,
I have mixed opinions about the plantations but I once planted over 300,000 trees myself on logged over lands, Reality is that I did it for $$ not for love and in many places the trees would have come back without me, but taking longer, People think I am a swell person for planting all those little trees but no........
Pam McElwee has an interesting take on the social costs of plantations in places,
Quite a lot written about Vietnam acacia plantations and I have been consuming many,
I will have more to say later on forest ecology.
You might be amazed to see the changes in A Luoi now,
Greg
Pictures are from 1969 and 2016. Photos are top of Ap Bia/Hamburger hill which was denuded by artillery and 272 bombing raids
https://www.facebook.com/greg.nagle/posts/10220700174107921
https://www.facebook.com/media/set/?vanity=greg.nagle&set=a.10222713819367794
https://www.facebook.com/greg.nagle/posts/10222698402862391
https://www.facebook.com/greg.nagle/posts/10222698337340753
Greg Nagle
PhD Forest and watershed science
Cornell University
Hanoi, Vietnam
On Wed, Apr 7, 2021 at 11:37 PM George Black <ghsblack@gmail.com> wrote:
Greg probably knows more than I do about this, but acacia has been promoted for many years by the government and international agencies for income generation. It grows rapidly and can be harvested in seven years - not only via large plantations but small plots that supplement farmers' incomes. It feeds the huge international demand for wood chips for low-cost furniture from buyers like Ikea.
646-361-3931
@georgehsblack
On Wed, Apr 7, 2021 at 12:21 PM Worthen, Helena Harlow <hworthen@illinois.edu> wrote:
Greg, what is the reasoning behind the acacia plantations?
Thanks — Helena
Worthen, Helena Harlow
On Apr 2, 2021, at 3:56 PM, Greg Nagle <gnagle2000@gmail.com> wrote:
Chuck,
I have a longer report with many more pictures but a few more below, Bad quality since I had to shrink them so much.
What you are seeing in those pictures are plantations which were recently logged , which is why they look so bare.
Such as this
Along with those plantations were the dense logging roads which have caused the problems in the pictures.
Worst section is the stretch between A Luoi and Hong Ha, east of there it looks much better, not so steep, Pics of that below,
The big change since 1996 has been the huge increase in acacia plantations near the road, on land which was sprayed 5 times with agent orange.
I am unclear about how the forest may have recovered without the tree planting, as I note below, recurring fires in the grass and shrubs may have much hindered tree regeneration. That is a view open to dispute, but an angle I am looking into more, Peter Ashton, Harvard forest ecologist suggested the same in the south,
Here is a more encouraging view of recovery after agent orange spraying which ended in may 1970.
You might note in the first 1993 pic the standing, charred trees which I assume were from burning in the much more fire prone vegetation which dries out in low rainfall season . Fires hindered tree recovery, the topic I am trying to do more research on since I think fires have had a huge impact across Vietnam for centuries. The French noted the same in their vegetation maps,
1993. Photo by Phung Tuu Boi
I am guessing that this is a bomb crater, perhaps not? But I have seen a number of anomalous places like this, This is in a a recently harvested acacia plantation,
Greg Nagle
PhD Forest and watershed science
Cornell University
Hanoi, Vietnam
_______________________________________________
Although there is little on the VSG list about environmental or science issues in Vietnam , I am passing this along so it gets into the right hands,
I have a much longer report on this which I can send to those interested, I do not want to embarrass anybody in Vietnam but the damage was extreme and it needs to be talked about clearly,
Pictures taken along road 49 between A Luoi and Hong Ha on March 21 , 2021. I think that this is unusually erosive terrain. It needs to be understood that worst erosion from logging is most often due to roads changing hillslope hydrology. East of here on hills not so steep, these erosion features are much less common.
I also saw landslides in some areas which were not directly impacted by roads or logging, Some may have been the result of deforestation by agent orange over 50 years ago or by bombs. But it also needs to be understood that some terrain is very prone to erosion even without direct human impacts. The recent storms in October and November 2020 made things a lot worse but these roads have been eroding for awhile. Extra caution needs to be taken in such terrain, What we are seeing here is serious soil damage with a worrying loss in long term soil productivity, Forestry cannot be sustained with such damage.
But also this on a more uplifting perspective further down the road,.
Forest recovery over 50 years in A Luoi after destruction by agent orange herbicide.
https://www.facebook.com/greg.nagle/posts/10222713868689027