I have friends in the Okanagan who managed to get some of the advanced species of Rapid Growing Hybrid Poplar from the research plantation they have in Vernon, BC.
They have a small lot, about 5 acres, with a good agricultural water supply, which they planted mostly with this hybrid. In the first year these seedlings grew from around 6" to almost 5' in height. In the second year, the trees were 10' high. By the end of year three they had a mini forest of 15' high trees. It was actually terrifying how quickly these hybrids were capable of growing - reminded me of something out of "Day of the Triffids" - one only wonders what would happen if these fast-growing hybrid-poplars somehow managed to start spreading...
My family owns a small pine plantation as an investment, and we were very lucky to buy our saplings right before the fery vast growth varieties came on the market.
The fast growth versions have extremely soft timber, its functionally useless, even the paper pulp mills only buy it at a discount.
They are probably vulnerable to storm damage too, but we haven't had to deal with that.
Might still be useful to build a wind break and out-compete introduced varieties in phases
This is why hardwoods are, uh, hard. They're typically slower-growing, so their rings are more tightly packed, giving the wood additional strength. I'm skeptical that the fast-grown trees from the article are as long-term healthy as naturally grown ones.
I believe that the "hard" actually refers to the fact that such trees have a harder shell for their seeds.
From wikipedia [1]
Hardwood is wood from dicot angiosperm trees. The term may also be used for the trees from which the wood is derived; these are usually broad-leaved. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.
Hardwood contrasts with softwood (which is from Gymnosperm trees). Hardwoods are not necessarily harder than softwoods. In both groups there is an enormous variation in actual wood hardness, with the range in density in hardwoods completely including that of softwoods; some hardwoods (e.g., balsa) are softer than most softwoods, while yew is an example of a hard softwood.
Any tree that grows quickly will have thicker (less densely packed) rings. The author describes a planting strategy that "tricks" the trees into growing more quickly than usual, so my intuition is that those trees will be weaker than they otherwise would be. The choice of species just moves the "natural" density point.
growing forest quickly =/= growing trees quickly. I might have missed something, but I don't think he mentions anything about making the trees grow faster.
The "tricks" are to mature the forest (i.e. make it self-sustaining) within 10 years, tree growth-rate notwithstanding.
I think the problem with soft wood and carbon sequestration are possibly the same underlying problem.
If they are still gathering sunlight and carbon the same way but gaining size quicker then there is just less carbon per cubic cm. There'll be some advantage in being able to get at more light and carbon sooner, but as carbon stored per square meter of land it's probably less.
That is not to say that you could not in principle make trees better, but I think the changes would have to be something fundamental to the cell physiology. A C4 carbon fixation pine tree might be better but it might be easier to turn bamboo into a pine tree than it would be to make a pine tree work with C4. Evolution is really good at balance, tweaking a bit can knock a lot off balance. It's not an impossible feat to make something better but it isn't easy.
They're more water, less carbon. So, they are less efficient at carbon sequestration in terms of density. And, they are probably easier for microbes to break back down so they hold the carbon for less time.
Poplars are considered to be among the best trees in terms of carbon sequestration according to studies done thus far. In addition, if they're converted to paper and other wood products, they continue to sequester the carbon for the life of those products.
I would regard it as prima facia deeply unlikely that processing wood into paper is carbon-negative, regardless of how long you then store the paper. It takes power to turn trees into paper.
It's easy enough to calculate: Do you need more than an equivalent amount of paper burned into energy, to make that paper.
The answer is no, paper mills power themself from trimmings from paper making. They use much less than the mass of paper they produce.
Making paper does not take very much energy. The energy used in cutting and preparing wood is not that much when compared to the amount of wood produced.
So yes, turning wood into paper is carbon negative (in a way, technically it's the growing of the tree).
Yellow Poplars in Georgia grow at pretty much that same rate naturally. When I was living there I let a portion of my backyard go from lawn to natural, and the poplars were amazingly fast.
They have a small lot, about 5 acres, with a good agricultural water supply, which they planted mostly with this hybrid. In the first year these seedlings grew from around 6" to almost 5' in height. In the second year, the trees were 10' high. By the end of year three they had a mini forest of 15' high trees. It was actually terrifying how quickly these hybrids were capable of growing - reminded me of something out of "Day of the Triffids" - one only wonders what would happen if these fast-growing hybrid-poplars somehow managed to start spreading...