Thread by @BobMuscarella

I'm very pleased to share the result of a big project @GEB_macro co-led by @ThaiseEmilio and involving LOTS of collaborators from 48 countries and many institutions.

🌴 The Global Abundance of Tree Palms 🌴
onlinelibrary.wiley.com/doi/full/10.11…

Read down for more...

But first: There are lots of important things to focus on right now besides a new paper.

e.g.,
#BlackBotanistsWeek
#StudentBan

We hope this serves as another interesting example of the power, value, and need for diversity in ecology. We are excited to share it!

On to the story:
🌴Palm trees are iconic tropical forest plants. At least in some places, palms are also very abundant. Did you know that 6 of the top 10 most abundant "tree" species in Amazonia are palms?🌴
rainfor.org/upload/publica…

🌴Palms are often considered keystone species as they provide enormous 'ecosystem services' for humans and other critters throughout the tropics. They are used for food, medicine, shelter and much more. Here are a couple examples:
nature.com/articles/nplan…
academic.oup.com/botlinnean/art…

As monocots, 🌴palms have very different anatomy and physiology from other woody plants. Unfortunately, we know very little about palm physiology and how they respond to drought and other types of environmental stress.

Our knowledge of 🌴palm tree allometry is also very limited because, unlike other trees, diameter and height are decoupled. This has implications for estimating biomass from field data, which typically involves allometric relationships developed for (non-palm) trees.

From an ecosystem functioning perspective, these issues probably matter most in places where 🌴palms account for a high proportion of forest biomass. But where is that? We set out to do a global analysis of tree palm abundance relative to other co-occurring trees.

We compiled forest inventory data from >2,500 forest plots involved with research networks @ForestPlots, @PPBio_INPA, #RAINFOR, and #AfriTRON to quantify 🌴palm tree abundance relative to other trees. (*Note that we focus on palms/trees >10 cm diameter... more on that below)

Before going further: Our study would absolutely not be possible without years of dedicated work by hundreds of people! Many are co-authors and many more are highly-skilled and dedicated botanists, taxonomists, field workers, and other who contributed immensely to this work.

So what did we find? Tree palms (>10 cm diam) were present in >80% of Neotropical locations and absent in most areas outside of the Neotropics*. Relative abundance of tree palms was >5x larger in the Neotropics compared to other biogeographical realms!
(*See caveat in next tweet)

*Caveat: Our analysis excludes palm swamps because they were not well represented in our dataset. But these are very important habitats throughout the tropics and they require additional work. See e.g.,
core.ac.uk/download/pdf/3…
nature.com/articles/natur…
mdpi.com/2072-4292/12/1…

Anyway, in our dataset, the relative abundance of tree palms was more strongly related with current environmental conditions (e.g., mean annual precipitation, soil fertility, water table depth, and plot-mean wood density) than metrics of long-term climate stability.

Note that outside the Neotropics (esp. SE Asia), palm assemblages include many climbing palms (like rattans) that are usually not included in forest inventories. For more on climbing palms see this fascinating paper by @tlpcouvreur et al.:
frontiersin.org/articles/10.33…

Finally, we show that tree palms add uncertainty to estimates of above-ground biomass, but really understanding this effect requires additional work on e.g. palm allometry. Some good examples of that so far include:
sciencedirect.com/science/articl…
link.springer.com/article/10.100…

This has been a very fun project to work on and has involved an enormous amount of collaboration with >200 co-authors from 48 different countries! This type of work is really only possible with the support of research networks like @ForestPlots @PPBio_INPA #RAINFOR #AfriTRON

@ThaiseEmilio and I co-led this project; other co-authors on twitter include: @BillJBaker @SimonLLewis @kofitim @tlpcouvreur @BiochangeAU @w_eiserhardt @JCSvenning @lu_falves @PoorterLourens @aroopsind @evilanova @LeeWhiteCBE @ForestPlots @JosBarlow @Erika_Berenguer ...

... @francisbrearley @fabi_sho @hculmsee @GDerroire @RhettDHarrison @a_levesley @ymalhi @BenMarimon @Andy_R_Marshall @toby_pennington

Here's a link again:
onlinelibrary.wiley.com/doi/full/10.11…

Hope you enjoy reading more about this fascinating group of plants! 🌴

/end