[tallowen]

I think we now know about a lot more externalities of this kind of logging than we did generations ago. For example, much of the hydrological basis that provide drinking water to the Seattle metro area was aggressively logged 100 years ago which impacts the hydrology of the basin in a negative way for the purpose collecting drinking water.

I think extra knowledge in the space of the environment often leads to indecision which is certainly it's own drawback but I think these choices are not without tradeoffs that should be acknowledged.

[poorman]

I'll admit I'm not up to speed on the affect of the aggressive logging of Seattle on the hydrological cycle. From the little time I've spent there, I managed to gleam one small fact, that by the 1950's the Seattle city sewage system was dumping up to 50 million gallons of sewage into the Puget sound (per day).

I'm only a software engineer and have no understanding of hydrological cycles, but I suspect the evaporation and precipitation of that alone would have an impact on the nearby watersheds used for drinking water.

[loeg]

> by the 1950's the Seattle city sewage system was dumping up to 50 million gallons of sewage into the Puget sound (per day).

Seattle started building water treatment plants in 1961 and they entered service throughout the 1960s: https://kingcounty.gov/en/dept/dnrp/waste-services/wastewate...

Meanwhile, Victoria, BC (Canada) continued to dump raw sewage into the ocean until 2021: https://www.cbc.ca/news/canada/british-columbia/victoria-sew...

[Arainach]

You'd be mostly wrong. The Sound is salt water and not a source of drinking water. Other bodies of drinkable water flow into the sound, not out of.

Pollutants don't evaporate with water. They're left behind. Acid rain was from pollutants in the air mixing with water droplets.

[_heimdall]

Everything has externalities though. Don't get me wrong I'm all for a forest going unlogged, but we will replace those resources with something else.

We still use lumber, if it isn't locally harvested we buy it from another part of the world, outsourcing those externalities and throwing in all the extra costs of shipping, labor overhead for the various middlemen, customs, etc.

My point isn't that we're screwed and should just chop down forests because we're damned if we do and damned if we don't. But saving one forest won't fix anything by itself and could very well make things worse if we don't do it by simply reducing the number of resources we consume. Paying someone else to own the externalities will never help.

[Teever]

What if America decided to import a lot of Canadian lumber? It's geographically close and the size of the forests are mindbogglingly vast.

Could this happen in a way that benefits American construction interests but also Canadian lumber exporting interests?

If there's ever some dispute about it could it be mediated somehow?

What would the outcome of that possibly be?

[thaumasiotes]

> and the size of the forests are mindbogglingly vast.

The size of the forests isn't really relevant; compared to lumber demand, they're mostly insignificant. Humans have never had a problem wiping out local forests.

What matters is how much wood a forest can produce per year, not how much has accumulated over the course of the past.

[carsoon]

There is plenty of timber in northern California and southern Oregon, these regions are actually temperate rain forests, that are harvested sustainably and aren't old growth forests. Every 30-50 years, (depending on species: redwood or doug fir) the same tracts of forest can be logged again and again.

Once you get further north the taigas are colder and slower growing and may take 200 years or longer to grow back.

The best thing for the USA is to use the resources which supports jobs in logging, wood processing, transportation, and have lower costs associated with transportation and fees from importation. I'm not against importing timber into very northern parts of the US but there is no reason to ONLY use canadian timber.

[oooyay]

The boreal forest aka Taiga is quite a bit more at risk than the forests of Oregon. There may be an argument to be made that the wrong kind of firs have grown in the south of Oregon (they're much more susceptible to fire from heat) and that logging and replacement with the right type of firs could be a win economically and environmentally. Somebody with specific knowledge would need to fact check that idea though.

[_heimdall]

You're still going to miss externalities when you limit the factors you consider. Sure, lumber sellers in Canada could do well and the US could avoid cutting downt heir own trees, but can we really assume that deforedtstion in Canada would be without consequence?

Assuming that stripping resources from other parts of the world is how we got into this ecological mess in the first place.

[rascul]

> What if America decided to import a lot of Canadian lumber?

Isn't that already happening?

[kalupa]

yep. in fact, it's the #1 import source

https://wits.worldbank.org/CountryProfile/en/Country/USA/Yea...

[Teever]

How does Canada feel about the state of the lumber trade between America and Canada?

[SCUSKU]

All very interesting and complex questions, I look forward to hearing your findings in 6 years at your PhD thesis defense :^)

[loeg]

Washington has absolutely tons of other lumber forest that isn't part of the Cedar River watershed, and it is still harvested today. We don't need to be logging in our drinking water watershed.

[_heimdall]

While I agree that we shouldn't be logging in Washington, is the answer really that we should just pay someone else to log in their watershed instead?

We need to not be logging, period. There's a huge difference in selectively felling trees locally and commercial logging. The problem is that we have collectively grown so accustomed to immediate gratification and the appearance of unlimited resources that we've completely disconnected from how the world really works.

If we really want to fix anything meaningful it's going to take people realizing that cheap energy from coal and oil, combined with paying someone else to deal with the immediate ecological damages caused, aren't sustainable approaches to living here.

[loeg]

I did not say we shouldn't be logging in Washington -- just not in drinking water reservoirs (which we don't). DNR managed logging / the Campbell Global Snoqualmie tree farm seem like mostly a success.

[_heimdall]

Do you know how much logging they actually do there? I haven't kept up with that project at all and can't find any recent data.

I know when they were first proposing the project the state was going to limit them to a couple hundred acre clear cuts and Campbell had their own limit at less than that. Unless that number increased dramatically, I'd say the project is a success mainly because they just aren't logging a meaningful amount of timber at all.

Someone actually just clear cut a few hundred acres down the street from me before the locals ran the investor out of town. It's terrible to see it cleared and it's basically just a massive, open, festering wound now but st the end of the data a few hundred acres of timber is a drop in the bucket relative to what we actually consume.

[loeg]

> logged 100 years ago which impacts the hydrology of the basin in a negative way for the purpose collecting drinking water.

Can you elaborate on the problems?

[RoyalHenOil]

Trees effectively behave as a buffer for the water cycle. Under conditions of high rainfall, they absorb a lot of water from the ground. Under conditions of low rainfall, they must nonetheless continue to release moisture via evapotranspiration, which promotes the production of rain in dry conditions. This mean that forested locations are more resistant to both floods and droughts.

Tree roots also greatly reduce erosion, which means that rainfall is more likely to end up in a few well-established waterways and less likely to be spread across numerous tiny rivulets; it also means that waterways are less likely to change shape over time. Large, stable waterways are much easier to collect water from (e.g., via dammed reservoirs) than small or unstable waterways.

However, I'm not sure how much of a factor erosion is here. I suspect it will only directly impact small communities that rely on minor waterways for drinking water. (Mind you, when small communities connect up to city water because their existing water supply becomes unreliable, that can affect the city's water supply.)

[loeg]

Sure, but this region is still heavily forested -- just with second-growth forest (trees ~100 years old and not older). Is there a significant difference between old growth and second growth for this purpose?

[tallowen]

From the recreational perspective (summer hiking / back-country skiing) - the forests are night and day difference. Having a map of what has been logged and what has not often is the difference between forests that are easy to travel through and forests that are harder. A forest that was clear cut will have trees that are much denser and tightly packed together but tend to be smaller in diameter. These are very hard to travel through (hiking or skiing) compared with the old growth forests.

I don't know a ton about forest ecology but my sense is that trees that do the best are a function of what's already there and that it takes much longer than 100 years for the pre-clear cut conditions to return.

[loeg]

The Cedar River Watershed is not open to recreational use (it's a protected pristine watershed that supplies drinking water to Seattle and surrounding suburbs). The difference for that use is not relevant here.

[RoyalHenOil]

A forest with larger trees and more extensive root systems will have a stronger effect than a forest with smaller trees with less extensive root systems.

Different tree species can also be more or less effective at functioning as a buffer. "Thirsty" trees typically do a better job of taking up water when it's wet and continuing to release water when it's dry. (Unfortunately, many new tree plantings favor more drought-resistant trees because they are easier to grow in clearcut fields, which are drier than forests.)

So, because I don't know much about this region specifically, these are my two questions:

Has there been a change in tree biomass in the region?

Has there been a change in the tree species makeup of the region?

[marssaxman]

They are most likely referring to the Cedar River Watershed, which supplies 70% of Seattle's water. While the city spent the 20th century buying up all the land so that it is now a protected wilderness area, plenty of logging happened during that time and less than a fifth of the old-growth forest remains. You can read all about it here:

https://www.seattle.gov/utilities/protecting-our-environment...

Specifically, here is the forest management plan, which goes into great detail about the current conditions, their effects on the water cycle, and the long term objectives:

https://www.seattle.gov/documents/Departments/SPU/Environmen...

I spent a few years in my 20s volunteering for ecological restoration projects in the watershed. We dug up old logging roads, removed invasive species (Japanese knotweed, ugh!), deconstructed landscaping left over from abandoned small towns, did erosion control along creeks in logged areas, restored riverside habitats, and planted lots of native trees and shrubs. I am not in touch with the organization anymore, but I'll always feel some pride in the work we did and a sense of connection to the place.

[loeg]

Yes, I assumed they were talking about the Cedar River Watershed (Chester Morse lake basin).

> Specifically, here is the forest management plan, which goes into great detail about the current conditions, their effects on the water cycle, and the long term objectives:

This is a 130 page document. The first few pages mentioning old-growth forest are mostly discussing habitat for fauna. Is there a more specific part of the document discussing hydrological impact?

> I spent a few years in my 20s volunteering for ecological restoration projects in the watershed. We dug up old logging roads, removed invasive species (Japanese knotweed, ugh!), deconstructed landscaping left over from abandoned small towns, did erosion control along creeks in logged areas, restored riverside habitats, and planted lots of native trees and shrubs. I am not in touch with the organization anymore, but I'll always feel some pride in the work we did and a sense of connection to the place.

Very cool! My only connection to this is that my mom worked for SPU in drinking water.