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Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sat Mar 05, 2016 1:11 pm
by IanW
This post isn't intended as a full blown travelogue (if I get time, I'll do one of those later!) though it is quite long, but more an update on the status of Cacti on St Lucia coupled with, what I feel are some interesting discussion points about what we know about populations, about how best to grow certain species, and when we should worry about our plants looking sickly. Some years back our very own David K wrote a short write up here on a population of Melocactus on the island here:

http://northants.bcss.org.uk/nl213/nl213lucia.htm

Knowing I was visiting myself, and having never actually seen Melocacti in habitat before I was obviously quite keen to try and visit them myself. I was however concerned given the state of the population's David visited that there wouldn't be anything left to see, as he rightly pointed out the population in the North didn't look healthy, and the belief was that there was only also a small population in the South wasn't encouraging.

I was able to make contact with a local forestry guide on the island but he wasn't sure about the North or South populations, he was however able to take me to a different population and I'm pleased to say, the plight of Melocactus on St Lucia may thankfully now look a lot more positive than was obvious looking at the populations in the North, and in fact, what at first appeared to be a problem with poaching in David's article leading to decline in the population, might actually be something else - the plants he saw may well be the establishment of new plants as expansion, rather than reduction from the remnants of poaching.

But before a few pictures, a brief word on what I observed about Cacti (and succulents) on the island. I was fortunate in that our holiday was very much and air, land, and sea holiday in that we took a helicopter tour around the island, our guide walked us through areas of the island almost entirely untouched by humans, and we did a lot of scuba diving from boats. This gave me the advantage of being able to see the island from just about every perspective, and one thing that was clear from every angle is that the Pilosocereus on the island loved the coastline being present on almost the entirety of the West Coast, dominating the entire surface areas of small rocky outcrops off the Atlantic coast isolated from the mainland, but also dominating the majority of the coastline on the North and West coast too. The Melocactus on the island seem to share the Pilosocereus habitat and this is why I'm actually a little more positive now about their future - I believe the population David witnessed wasn't necessarily simply a population decimated by poaching, but may well be a population spreading from a coastal location inland. I have reason to believe that due to things like coastal collapse from erosion, and mud and landslides that are apparently common in periods of heavy rain (especially when hurricanes have hit in the past) that the populations here may well be incredibly fluid in their coastline based survival against the forces of nature and it is that that means there are often still relatively new looking populations, rather than human interference. A large part of the reason I believe this is that in the population I saw there was also a rather new looking population in a similar state to that which David saw, but that was situated not far from a very mature population - if it was poaching it would seem odd for them to leave such a mature population so close.

To start, I'll highlight an example of the coastal collapse that is apparently not entirely uncommon in the area of habitat I visited:
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Another key feature of this landscape is that it's constantly battered by the northeasterly trade winds that cross the Atlantic from Africa (much like the jetstream that moderates our temperatures), so much so that the vegitation of the entire landscape is shaped by it:
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Even some of the Melocactus cephalia weren't immune from the effects of this strong wind:
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The first sign along this coastal strip of succulents are the Agave caribaeicola:
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There is a healthy population of this on this part of the Eastern coast, as you can see here in this panorama (hence the odd image dimensions):
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The first Melocactus population is that which I previously mentioned looked rather young with no mature specimens, and sat about maybe 200m from the mature population (but within sight of it):
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And also this specimen, which I bravely push my fingers in to confirm what appeared to be the case that yep, this surprisingly fatal looking damage wasn't, the split was calloused as hard as a rock and didn't seem to be a permanent impediment on the plants ability to survive:
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Moving down the coast we reach our first Melocactus, but also mixed in with Opuntia triacanthos, and Pilosocereus royenii:
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Behind me were some more, very mature Melocactus intortus, sat amongst the Agave:
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And I guess Colin, if you're reading this, maybe your Agave aren't so bad after all if they're willing to act as nurse plants for my Melocactus:
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It's hard to describe the beauty of this place in a way that does it justice, pictures don't do it, though they do paint a good picture still. You may notice in some of these places that coral reefs are just visible in the sea beneath these plants, but this area is too dangerous for scuba diving - all our diving was done on the much calmer West coast. The Cacti are happy to live precariously on the edge (but who can blame them with that view?):
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Damage and deformity is not uncommon, but also, apparently, not much of a hindrance. Marks, scars, and apparent discolouration seem to be part of the natural cycle and nothing much to worry about. I previously thought I was doing wrong when some of my Melocacti looked a little more yellow, or had a few blemishes on, but it's normal and incredibly common in habitat:
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I'm also not convinced by the keep Melocactus in small shallow pots little bigger in diameter than the plants themselves with a bit of gravel around the base theory anymore. These roots tell a different story being spread wide, and visibly present on the surface. We obviously have to compromise on space in our greenhouses, but a bit of free root run, with the roots being next to or on the surface seems to be the natural state of all the mature Melocactus I saw:
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The population here is in great health:
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Opuntia triacanthos at all stages - bud, flower, pollination, fruit:
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This highlights my view that these populations are probably fairly dynamic and regularly shifting, I suspect these aren't too far away from suffering a landslide type fate:
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This Agave was a monster, the picture doesn't do it justice, the plant alone even without the flower spike was more than twice my height:
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This landscape, a peninsula had some trees at the end of it, in those trees there was also Acanthocereus tetragonus:
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Just to my left was this area, with Pilosocereus royenii and Melocactus intortus living precariously alongside an ocean blowhole (sorry for the lensflare):
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These were also growing in the rocks, I'm afraid I can't remember the name. Aizoaceae sp. I believe:
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What I believe was another Aizoaceae species was growing on our way back in the mangroves. I'm not sure what would drive a succulent here, given that it was right in the middle of a run off into the sea that all the rainfall drains to, I couldn't think of a place more wet as the second picture shows the area opposite that the water runs off too:
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Later that day we decided to take a trip to the North East, an old British colonial fort at a place called Pidgeon Island (that isn't actually an island anymore) where we were able to see much of the reproductive process of Pilosocereus royenii in action thanks to a Greater Antillean bullfinch - again, flower, non-ripe fruit, ripe fruit, seed dispersion mechanism (the bullfinch):
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Like the earlier Melocactus, this species also seemed to enjoy a beautiful view of a reef in the background:
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Opuntia dillenii was also present up here:
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It wasn't news to me that we mollycoddle our plants far more than they get in nature, but my take away from all of this is that sometimes some of the things we see on our plants and worry about are not actually anything to worry about at all - that when sometimes our plants look a little sickly, then may well not be and may be doing just fine. I learnt a lot about how and where these Melocactus grow, and intend to try growing some quite differently to examine the effects. I learnt that my seedlings and young plants look exactly as seedlings and young plants would be expected to look in habitat, and about the Melocactus of St. Lucia, I realised that they're in a constant battle with the forces of the ocean and geology, and that populations that may at first glance appear to have been the victim of poaching may simply be just examples of shifting habitats as a result of that never ending battle. I saw Bromeliads, and Orchids growing with our plants and saw termites playing their part in recycling detritus for our plants to consume for food (not shown- this post has gotten long enough as is!), but once again above all else I was reminded about the absolute beauty of habitat, and why these must be protected. The good news is that for now, the Melocactus population on St. Lucia looks quite safe, and that's extremely promising - the difficulty of traversal of the terrain to get to this population (it couldn't have been done without such an excellent local guide) coupled with the constantly strong Atlantic winds and general geography means that I hope this population will remain safe for the foreseeable future.

For what it's worth, our guide suggested the lowest the temperatures get around the Melocactus area is about 13c - 14c for short periods (it was about 31c when we were there), this somewhat reinforces my experience that 12c is probably too cold to consistently keep Melocactus healthy over winter, my Melocactus suffered a lot more when I dropped from a winter low of 15c to 12c and are much happier now I've increased back up to 15c+.

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sat Mar 05, 2016 4:35 pm
by Liz M
What an interesting and informative post, with some reassuring news. Thanks for some useful information and some really super pictures. I look forward to the next posts.

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sat Mar 05, 2016 5:16 pm
by Brian
(tu) Ian, what a very interesting post and worthy of a Cactus World article. Melocacti seem to be walking down towards the sea in droves. Love the sight of the pilos hanging off the side of the cliffs. I was on the island in December and the climate was very different from UK: never below around 28 degrees day & night, & generally windy, with fair degree of moisture and rain. These are conditions we can never recreate in a greenhouse without costly heater and fan running - so I will not be trying!

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sat Mar 05, 2016 5:25 pm
by Tina
Very interesting, love the melo with the slanted cepahleum.
Super pictures too,
Thanks Ian

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sun Mar 06, 2016 9:15 am
by Paul in Essex
Wonderful stuff - definitely needs to be in print!

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sun Mar 06, 2016 5:12 pm
by David_K
Hi Ian,

Great to see that the areas you visited still had very viable populations. However
what at first appeared to be a problem with poaching in David's article leading to decline in the population, might actually be something else - the plants he saw may well be the establishment of new plants as expansion, rather than reduction from the remnants of poaching.
was definitely not the case. The person who took me to the site I visited was a local plantsman and he was quite taken back by the lack of mature plants which he said had been there the previous time he had visited the site only a few months previously. I am extremely pleased that you found other areas that are still thriving.

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Sun Mar 06, 2016 8:08 pm
by Apicra
A good read! Interesting to hear about the state of these cacti in the wild - I guess locals dig them up for their gardens?

Best wishes,
Derek Tribble
Harrow Branch

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Mon Mar 07, 2016 1:47 pm
by IanW
David_K wrote:Hi Ian,

Great to see that the areas you visited still had very viable populations. However
what at first appeared to be a problem with poaching in David's article leading to decline in the population, might actually be something else - the plants he saw may well be the establishment of new plants as expansion, rather than reduction from the remnants of poaching.
was definitely not the case. The person who took me to the site I visited was a local plantsman and he was quite taken back by the lack of mature plants which he said had been there the previous time he had visited the site only a few months previously. I am extremely pleased that you found other areas that are still thriving.
A shame to hear that David, I guess if nothing else it does still seem clear that these plants can repopulate quite successfully from the impossible to reach cliff growing specimens.

Between the crashing waves on the east coast (there's a big wave visible in one of the pictures posted above that highlights what I mean!) and the general fragility of the coastline there, I think people would have a hard time descending down or ascending up those cliffs to collect from the cliff sides - it would effectively be a suicide mission. Even if collection does eventually seriously effect this population I think the island is fairly safe from seeing extinction of this species if nothing else.
Apicra wrote:A good read! Interesting to hear about the state of these cacti in the wild - I guess locals dig them up for their gardens?
I actually tried to keep an eye out for this, and I saw a few examples of Opuntia dillenii and Pilosocereus royenii in people's gardens, but no Melocactus visible. That doesn't mean they're not there of course, but if people are collecting for their gardens rather than other reasons (i.e. illegal export) then they are at least not commonly displaying them prominently as trophies. This could of course just mean they're keeping them in hidden parts of their gardens out of public view, or it could mean they're simply failing to keep them alive for long.

Many people regularly appear to grow food bearing plants in their gardens- almond, cashew, banana, papaya, sweet orange, coconut, cacao, passion fruit, and so on.

Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Mon Mar 07, 2016 7:00 pm
by IanW
Slightly off-topic, but on the off chance anyone is interested I just copied a few underwater images off the Go Pro, this place is just as beautiful beneath the waves and were some of these species to be seen on land you could probably mistake them for Cacti or succulents as the structures, shapes, and growth patterns are not always too dissimilar! Colour reproduction isn't perfect as I've not yet perfected underwater colour filters on the camera, but here you go:

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Re: Cacti and Agave in St Lucia (Warning: Lots of images)

Posted: Wed Mar 09, 2016 12:19 pm
by RAYWOODBRIDGE
Nice article Ian, yes I have heard from other Melocactus locations that they can withstand salt water crashing over them without too much effect, something we would never dream of looking at our plants back in the greenhouse, shows they are much more resilient than we give them credit for.