Today I summarized some of the reasons for the nutrient-poor soil of the tropical rainforest. The over-riding issue is the steady rainfall. As we discussed last semester, water is a super efficient solvent, and whatever nutrients reach the soil of the tropical rainforest are dissolved and leached into deeper levels of the soil where plant roots can't reach them.
Another reason for the nutrient-poor soils of the tropical rainforest: Most of the plants are evergreen. Rather than returning nutrients to the soil, they hold onto their leaves, preserving the hard-to-obtain nutrients like nitrogen and phosphorus within their own plant body. Sometimes leaves will stay on a plant for years, enough time for lichen colonies like this one to establish and thrive. You can determine through a quick visual that there are several species of lichen on this leaf, another example of rainforest diversity and biological complexity.
One of the most striking features of the rainforest floor is the fact that any organic matter that falls is quickly utilized by micro-organisms like fungi or the many insects that make use of plant material for their nutrition. Here's a picture I took in Mexico of a termite "highway." Under the protective layer termites are rushing to and from their nests with leaf material.
Perhaps most exciting of all was the chance to see the activity of leaf-cutter ants, which play a complex and vital role in the rainforest ecosystem.
Although the thought of it scares me, the termite highway is actually pretty interesting to think about!
ReplyDeleteIt's interesting how the rainforest is another example of the Mechanistic Theory and adaptation. When I was in the Japanese Bamboo and Rainforests, I never thought about how poor the soil was for the plants, instead, I wanted to get into air conditioning as soon as possible.
ReplyDelete-Emily Brewster
Before class today, I always envisioned tropical rain forests as colorful, wet and lush. I never associated it with having poor soil, it just doesn't add up appearance wise, since rain forests are so full of life and color. But after learning about it, it makes sense that the evergreen trees would impact the soil as well as the rain and lack of nutrients.
ReplyDelete- Lindsey Felcher
How interesting that leaves can sometimes stay on these plants for years at a time... and the photo of the lichens reminded me of how there is still so much biodiversity we are unaware of because it appears in easily missed or unexpected places.
ReplyDelete- Gunita Singh
I could not believe that rain forests have such bad soil. With all the different types of vegetation I did not think it would be possible. But the fact that the trees keep their leaves is pretty interesting because it gives the lichen that grows on the leaves a chance to thrive.
ReplyDeleteKevin Walsh
I didn't realize how many different types of trees the rainforest has. It's interesting to see how some trees such as the evergreens can have a negative effect on the nutrients in the soil.
ReplyDeleteBrittany Sebade
Prior to class today, I was unaware of that the spots on the leaves of evergreens are lichen. I had previously that such spots indicated the aging of the leaf. It is interesting to note how much biodiversity can exist on one plant.
ReplyDelete-Cheryl Tang
It is clearly very extraordinary how every single organism in this tropical rainforest plays a vital role in utilizing all their resources to preserve the natural habitat of the botanic environment. Specifically, pictures captures regarding the micro-organisms such as fungi and insects caught my attention. They represent the produce and consumer of the ecosystem. Both of them take advantage of the climate as they can also act as a catasylt protein to the environment.
ReplyDelete-Lena Wang
I remember walking in a rainforest in Australia many years ago and the soil was so wet that it was gross to constantly step in mush. At that time, I thought it was probably the best kind of soil to grow things, what did I know. The weather was humid and the temperature was so high that I saw many large insects roaming around the grounds. What I found interesting was a colony of big green ants moving food through a "highway" like the one above. It was the most fascinating thing to watch, until it started mistaking us as food. Naturally, that did not end very pleasantly for us.
ReplyDelete- Thomas Cui
Like Cara said above, I would have never assumed that a rainforest's soil was poor. Something else I also found interesting about today's lecture is that rainforests are very susceptible to human impact.
ReplyDeleteWhen I think of heavy rainfall, I only think that it will be good for plants and wildlife but I know now that too much can have bad effects. Also, it is amazing how organized those termites are.
ReplyDeleteIt's amazing how plants fend for themselves and hold on to their leaves in order to obtain nutrients they know are hard to obtain. It seems like plants find ways to adapt to a wider range of environments than I had originally assumed. For example, the cactus that you showed us in class adapted to a tropical rainforest.
ReplyDeleteWhen i went zip lining in Ecuador a few years ago across a Tropical Rainforest i was unaware about all the diversity of plants beneath me. Reading your blog now is interesting because i did not know of the poor soil that the plants were growing in and everything that was happening in the ecosystem.
ReplyDeleteI was also quite fascinated by the fact that the rainforest has such poor soil. I just always assumed that because it supports such a diverse and lush range of species that the soil would be fertile, but it is not.
ReplyDeleteJust as everyone mentioned, I was very surprised to learn that rainforest soil is low in nutrients. After thinking about water’s properties it does make sense. The rainforest is so diverse, yet they must adapt to similar conditions, such as low nutrients in the soil.
ReplyDelete-Matt Auerbach
I am also very shocked to see that the rainforest has such poor soil, yet there is still so much life in the rainforest. I also think it is so interesting how microorganisms use plants for their nutrition. Like many other people, the way that the ants help each other carry food supply and work together to protect themselves fascinates me. Thank you so much for sharing this with us!
ReplyDelete-Emily Shalev
Thanks Professor Hammer for this post. This is very interesting and fascinating. It's incredible how poor soil can create so much biodiversity and how so much biodiversity can survive in such conditions. The world is really a unique place!
ReplyDelete- Stephen Wong
This was really fascinating, because I never had thought about how harsh conditions in rain forests were. I did not think about how the constant rain was actually in a way hurting the plants, and how there is very little solar insolation.
ReplyDelete-Julian Tantzen
The ants really are fascinating! I also never realized how nutrient-deficient the soil in rain forests are.
ReplyDelete-Silvia
Sorry for such a late reply. I completely forgot to write here, but this blog helped me to study for the test. I would never guess that rainforest has such a poor soil. Moreover, I always thought it has the richest soil. Good thing you taught us about it. It's interesting how anything that falls down is basically utilized immediately. It is also strange in a way that leaves can stay on trees for so long! I guess I just always have a chance to observe the changes in the season, but there are just so many places on Earth that don't have it.
ReplyDeleteThanks,
Diana Freyman
Sorry for the late reply. It is hard to believe that the soil in rainforest is so nutrient poor. You would think it would be lush and full of life, but considering that the trees are evergreen and do not shed there leaves, it makes a lot of sense.
ReplyDeleteThanks
Kristen Henlin
I think its so interesting how the soil in the rainforest has so much poor soil. I found it interesting how the leaves can stay on the trees for so long and the animals living there use it to there advantage like the ants and termites. I like that video of the ants moving through the rainforest I thought that was really cool how they move so fast.
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