China changed water cycles by planting billions of trees

[Wout Hoff]

Good morning all

I came across this article:

https://www.livescience.com/planet-earth/plants/china-has-planted-so-many-trees-its-changed-the-entire-countrys-water-distribution

May I ask for peoples views on this?

My view was always "more trees is better"

Can we predict how rainfall patterns will be affected if we restore degraded land by planting trees?

Kind regards,

Wout Hoff

Groasis B.V.
West-Havendijk 112
4651 VZ Steenbergen
The Netherlands
M +44(0) 7876 577032
T +31(0) 6 1718 4539
www.groasis.com

Confidentiality Notice:  This email and attached document(s) may contain confidential information intended only for the addressee. If you are not the intended recipient, you are hereby advised that any disclosure, copying, distribution or the taking of any action in reliance upon the information is prohibited. If you have received this email in error, please immediately notify the sender and delete it from your system. Thank you.

[Sheil, Douglas]

"more trees is better" –often, but depends where you are and what trees. There are multiple effects involved that operate at different scale—for example, infiltration and atmospheric transport.

 

In dry areas more trees can make it drier and in wet areas it can make it wetter. See for one summary here:

https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.16644

The point is that tree cover can deplete water too though this is often overemphasised (due to past studies focusing on plantations in dry regions that shouldn’t support dense tree cover), see https://www.sciencedirect.com/science/article/pii/S2197562025000855

 

On dry degraded soils intermediate tree cover is often much better than none even when dense cover is also not desirable: https://www.nature.com/articles/srep21930

 

Timing matters too. Introduced species can be maladaptive. Native species with locally adapted phenology (when they leaf and transpire) is key.

 

Ideally don’t plant when you can simply promote local regeneration/regrowth. Plan for a self-sustaining system

 

In general, I would say “follow nature” in terms of vegetation structures/covers/densities and compositions.

 

For some general overviews see: https://www.sciencedirect.com/science/article/pii/S0959378017300134 and my own, https://link.springer.com/article/10.1186/s40663-018-0138-y?fbclid=IwAR07VSVqp34OEJqHrwqMVncrVTfXWNJgrMXZzJxtDSKSQVcObEorAgsDLTw

 

“Can we predict how rainfall patterns will be affected if we restore degraded land by planting trees?” … yes, we can approximate this for small scale changes. For large scale changes (where the moisture tracking is not enough because circulation will also change) it depends on the confidence you put in the models … certainly you can get “a prediction” but different models give different predictions …

 

 

Douglas

--
View this message at https://groups.google.com/a/googlegroups.com/d/msg/ecorestoration-alliance/topic-id/message-id
 
Group emails flooding your inbox? Click here: https://groups.google.com/g/ecorestoration-alliance/settings#email
 
Our website is at http://EcorestorationAlliance.org/
Our calendar is at https://tinyurl.com/EcoResCalendar
---
You received this message because you are subscribed to the Google Groups "EcoRestoration Alliance" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ecorestoration-al...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/ecorestoration-alliance/CAJrob5CDR3ga7dpGMBNxPfk9uJsdyY1Ks-uj3UPy402%2BegSKuw%40mail.gmail.com.