Forests of the World

Baobab trees are in news because some of oldest ones are dying. Hard to tell if this is premature or serious. Anyway it may stimulate interest in health of other size classes. I'm aware of no research on how fast they grow, which is a large knowledge gap, as somethings go.

Quite unusual among trees, worth your effort to at least look at pictures.

 

Perhaps some here guess my peculiar interest in these trees. New piles of a most unusual wood, ready to have their decomposition studied! There may be conflicts with 'exotic wood' furniture makers, so let's just keep this among ourselves.

 

Can be 10 meters diameter at base which is novel in places where soils are almost always dry. Living stems hold amazing amount of water compared to other wood.



Dried wood density is very low. Other low-density woods are found in everwet soils and are fast growing (like balsa). But baobab grows slowly. It is weird, even without looking at the canopy. That's what most people notice.

 

This introduction to trees communicating could probably not be made any simpler:

If it is thus beneath our audience I apologize. Real key to this story is stable 13 isotope of carbon, and mass spectrometers getting priced for wider utilization.

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A new redwoods preserve is being set up for public access:

Harold Richardson Redwoods Reserve | Save the Redwoods League

All to the good, and (attempting to connect ideas here) very long lived trees might be most likely to chat via fungi. Very little study of that yet.

Redwoods persist in about 4% of their original range. When people managed to make saws big enough, well, that was a real turning point.

 

US forest fires are large and media clicky. Readers should see

National Interagency Fire Center

That 2018 burn to date is (in acres) behind 2011, 2015 and 2017. Ahead of other years since 2008. Clicky perhaps because this year some fires have grown quickly and involved structures.

If you see 2018 to be end-of-worldish, it may be that click-sites got you. It is bad and likely to become worse. It is not unique. As in every fiery year, folks living 'at interfaces' and managing bridge-fuels not best are at risk. Some suffer a lot.

 

Wood, after holding leaves up at light-competitive heights and piping in water, dies and gets decomposed by fungi. Otherwise, we'd be hip-deep in deadwood, and one could scarcely imagine all the coal.

All old news to kind readers here. But among those fungi, more than a few make really odd chemicals, including hallucinogens and toxins. Has seemed mysterious.

Recent work (published 2018 Jan and I should have noticed it sooner) suggests that fungi played such dirty tricks on insects. Who'd otherwise eat fungi themselves or compete for decomposable goodies.

(Evolution Letters 2-2: 88–101.)

Notable also for suggesting how genes involved may have hopped among fungi quite distantly related.

No other 'stories' on this subject exist, so we'll go with this one for now. Surely this chemical warfare is not aimed at humans. Having appeared 3 or 4 orders of magnitude too recently, we are collateral damage.

 

Trees and bees

Trees are harvested from many forests. Not news. Odd bods like me think that leaving some wood behind to decay is a good thing. However, some wild bees important for pollination seem to prefer cleaner scrapings:

Logging site slash removal may be boon for wild bees in managed forests -- ScienceDaily

So, it's complicated. As the saying goes.

 

Oil palm is attractive for forest conversion in tropics. Annual yield peaks at about $2400 per hectare. This at current commodity price far below 2008 and 2011 peaks, but there is a 'floor' because palm oil can be both food and fuel.

So, Africa would join Indonesia etc. in planting 'money trees'. Potential conflicts with primate conservation are described in a new publication:

Small room for compromise between oil palm cultivation and primate conservation in Africa | PNAS

 

Current status of American Chestnut. In past it played large roles in American psyche and forests.

American Chestnut -- a photo diary.

Comment section includes old photos of impressively large trees and a Van Gogh painting.

 

Not only Baobabs, odd trees can be found in Australia:

Grass trees aren't a grass (and they're not trees)

Similar 'lillies' occur in N. Amer. deserts. Yucca, and perhaps better-known Agave (tequila precursor).

 

This extreme fan of wood, especially after it dies, is having a fundamental perspective shift that few here will care about. Posting it anyway

Trees, obviously, make wood and go single-stem vertical and preempt photons for photosynthesis. Shrubs make multiple woody stems and preempt photons in a mostly horizontal way. But wood is not in some plants and lacking in others. Instead, the gradient is very smoothly expressed across photosynthesis doers.

Photosynthetic plant cells do very well with only cellulose for walls. But other cells transporting something to somewhere else need rigidity that cellulose cannot provide. Lignin, welcome aboard. Ancestral seaweed (mysteriously) had the maker genes but never bothered with them. Every land plant with 'tubes' does lignin because no alternative has arisen. Some do it to the highest degree that gravity and water cohesion allow, but wood as such is only an endpoint. Palms, lilies, cacti and asparagus among others express it their own more humble ways.

 

Trees move seeds beyond current distribution ranges assisted by rodents and birds. That assistance is very important for latitude but perhaps less so for altitude. In latter case, tree species that have been studied are moving uphill about 2.5 meters/year in tropics and 5 meters/year in temperate climates. Trees can throw seeds that far without help.

Seed landing and germination does not ensure survival of new tree to seed-making age. Root-interacting fungi and herbivores both need to be 'accommodating' in the range-expansion area. Some introductory material:

Plants have unexpected response to climate change | Science | AAAS
Forest migration - Wikipedia
Half of All Species Are on the Move—And We're Feeling It
https://www.annualreviews.org/doi/abs/10.1146/annurev.ecolsys.37.091305.110100

People planting seedlings (etc.) is called assisted migration. A large topic area all by itself.

There is a 1997 overview of the topic by Pitelka et al. in American Scientist, with free copies scattered around internet. Parmesan 2006 (above) is free here:

http://www.fws.gov/southwest/es/documents/R2ES/LitCited/LPC_2012/Parmesan_2006.pdf

 

We all miss something But as long as funding can oxygenate blood of research, wounds can be healed.

But let me understand your point better. Is it that long-lived plants, that only do sexy things after long childhoods, are less able to move long distances? If so, I'd not agree. Distant plant offspring generally require animal helpers. They need to be paid. Seed rewards of large (old) plants are much better than those from short-lived little ones.

Botanists focused on small, fast plants don't get much respect in forest ecology. Seems to be because we assume there will always be 'an understory'. If details there are important to the 'story' of how forests begin to occupy new places, research has yet to reveal them. Invasive (not from here) smallish plants are rushing in to fill any voids. But I digress.

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Another aspect of poleward or upward forest migration is soils. Lots of old-cold places had glacial scraping, leaving less-hospitable brown stuff. One cannot always assume that optimistic efforts by plants and animal friends will yield, um, fruit in such places.

All that dwells within earth history within which 60 million years ago was pretty hot, and after, several glacial cycles, throughout which modern (ish) plants of all statures and tempos have managed well (enough). There would need to appear something new and pernicious about this current climate excursion to break that chain.