amori
Urceolatae
Posts: 21
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Post by amori on Sept 21, 2010 6:28:41 GMT -10
What I meant by it is that compared to what fruit and veg are grown in, Nep soil is rather poor in nutrient levels - not to say they are absent, but depleted or easily flushed away nonetheless.
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Post by rainforest on Sept 21, 2010 7:38:00 GMT -10
The technological botany of this book is wonderful, I have no qualms on that, I am simply in hopes that the newer books published would grasp the idea that nepenthes are like no other carnivorous plants that they are capable of normal plant cultivation with the added supplementation of pitcher absorption. The ecosystem that nepenthes grow in is a diverse one where all plants are subject to similar conditions but by no means sterile or lack of nutrients. Even the coral reef has a diverse organism group where the constant flow of nutrients (no different than what nepenthes and other plants are subject to) allows these organisms to thrive. The nepenthes communities are a complex group of plants and animals all thriving in each other's space. The idea of poor nutrients doesn't make any sense, especially when other non-carnivorous plants are also capable of thriving as well.
There are nutrient deprived areas where true dependance of carnivory exists. These would be like peat bogs where the VFT really do depends mainly on insect prey.
Nepenthes roots are not for support exclusively. Their main function is for nutrition gathering.
M
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Post by morbus on Sept 21, 2010 11:18:14 GMT -10
my post was very much in support of what you , and others said Micheal. I was just offering a possible explanation as to why they may have developed carnivory when they seemingly dont need it to merely survive. My mentioning of rain forests and coral reefs is that they are extrordinarily extraordinarily complex systems - there diversity of life is well known to all of us. so, despite being labelled as "nutrient poor" systems - they support all that life. so, i thought maybe "nutrient poor" is misleading, hence the explanation i added. I think Nepenthes habitat "nutrient poor" and other CP habitat "nutrient poor" are very different, and labelled as such for different reasons! I have seen Drosera Capensis and other in their natural habitat here in Cape Town - their soil is very dead. trust me. . . .its not fertile at all. I doubt most Nepenthes Habitat can be that in fertile. Its just that their food is harder to access albeit plentiful. again - im not apposing anyone, just offering possible reasons also in support of what you said - i dont agree that fertilizing neps should be avoided as the book said. on VFTs - i fertilize my VFTs (and sarracenia and Drosera) with the same mixture i give my neps. they seem fine with it. Honestly, I think they (and their roots) are just like any other plant. But their carnivory gives them an advantage when food is scarce in the root region.
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Post by morbus on Sept 21, 2010 11:33:49 GMT -10
this is the 800th topic on the forum
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Post by rsivertsen on Sept 21, 2010 11:45:40 GMT -10
I've had these discussions with quite a few people in the Nepenthes scene, and we generally seem to agree that these plants originally developed these adaptations in order to store water first so that they can survive the killing dry spells in between the rainy, foggy wet seasons, and those plants would probably get a significant amount of insects, millipedes, and other nitrogenous matter caught in their pitchers. Those plants that developed the means by which those nutrients could be absorbed along with the water, and also could assimilate them for their own benefit began to proliferate more than those that could not, and those who developed the means by which they could enhance the breakdown of insect proteins by producing enzymes, and nectar glands for attraction again had the advantages which enabled them to proliferate into places where few plants could compete with them, such as the barren sandy, rocky (lithophytic) or epiphytic conditions in which they grow. I'm sure it was a series of small evolutionary steps that eventually produced the genus we have now.
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Post by agustinfranco on Sept 21, 2010 12:14:37 GMT -10
HI Rich:
After reading several posts about the issue and growing these plants myself, i've come to the conclusion that Nepenthes are like most plants because they evolved from some sort of non-pitchered plant. Since most plants use their roots to absorb water, minerals, and any dissolved low molecular weight nutrients, then Nepenthes must do too. The fact that they developed pitchers to enhance their feeding or water catchment techniques may be a different issue altogether. There is very little doubt that these plants also feed from their pitchers, but it does not mean they can't be fed through their roots.
Bottom line: what happens when you feed a nepenthes both ways: pitchers and roots, can these plants be overfed hence plant rotting or dying. perhaps there must be a calibration on the amount of nutrients each plant requires. Exaggerating root feeding must be problem for neps, but by regular feeding either way: roots or pitchers.
Gus
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Dave Evans
Nobiles
dpevans_at_rci.rutgers.edu
Posts: 490
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Post by Dave Evans on Sept 23, 2010 12:31:34 GMT -10
Most soils that naturally support Carnivorous Plants are poor in available nutrients. Many times acidic condition keep nutrients bound in place and therefore not available. Iron can crystallize on the surface water saturated with tannic acids.
There are nutrients present, but they are most often not available and so the plants experience "poor soil" conditions. Plant just about any crops, except for blueberries and cranberries, and they will fail.
People are not understanding that 'nutrient poor' is not a replacement for 'no nutrient'.
Nepenthes need nutrient poor soils for two reasons. First, they grow slowly and are non-competitive. The poor soil conditions slow other plants down enough for the Nepenthes to keep up with them. If there were more nutrients available to all the plants, the areas 'safe for Nepenthes' would be greatly reduced. This is why Nepenthes are colonizing species. One of the first type of vegetation to show up after a landslide or fire.
The idea, in turn, Nepenthes need poor soil conditions in cultivation is sort of dyslexic. You're running the logic back wards here. The plants evolved carnivory to deal with low nutrient levels. Now they rely on low nutrient level to maintain a competitive advantage over neighboring species of plant. Is competition from neighboring species of plant a problem in cultivation, when you the grower, makes room for the Nepenthes? No. You're effective killing off the competition for the plants. One of the main reason they 'need nutrient poor soil' has be removed from the equation.
And two. Now that they are adjusted to poor nutrient levels, you don't want to fertilizer them at the same levels one does for garden plants, and you don't want to use the same kind of fertilizers either; this is true of many orchids as well.
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Post by rainforest on Sept 25, 2010 10:51:46 GMT -10
Nutrient deprivation is what most writers post when describing the soils of nepenthes. This has not been the case in any closed system experiment trying to prove/disprove the notion that nepenthes are carnivorous because of poor soil nutrients. Many times soils may contain toxic levels of nickel, lime, and other high quantities of micronutrients, this is not to point to the fact that they are lacking important nutrients, but rather postulating that nutrients are contained in this toxic mixture. Plants growing in the same region for many millenia usually have ways to adapt to growing in these conditions and ignore the fact they they are growing in it. This would explain why your N. rajah grows well, even when not grown in an ultramafic soil condition in your care. or how N. northiana doesn't require limestone to grow out of it's natural growing habitat. In short, nepenthes thrive in nutrient sustainable soils being fertile or infertile, as well as growing in soils that are limestone concentrated or acid. This would explain why nepenthes grow well if you're using a peat perlite mixture or cinders and bark-coco coir and so on. The important feature to bring all of these media to work well is the introduction of soluble nutrients from an outside source. The process of carnivory works along side root introduced nutrients for nepenthes as a supplemental nutrient source. This would explain how juvenile plants can establish themselves even before developing sizable pitchers to actual capture prey.
M
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Post by christianjames on Jan 2, 2013 12:57:46 GMT -10
This was an excellent thread, lots of great discussion!
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