Open Economy, or Not: sustainable evolution of mycoheterotrophic plants?

 

So, a sort of folk interpretation about the status of orchids says, they are the most advanced plants as they economize the process of eating (and procreating) by utilizing fully mycorrhizal fungus. The spring orchids I listed last week are commonly found in the forests of Kanagawa prefecture, Yokohama included. In addition to beautiful flowers, they have green leaves which could fool people to believe they are not much different from tulips or pansies that can be nurtured easily in ordinary gardens. ... Many people casually dig them up for a flowerpot, which makes them starve without proper soil ecosystem of fungi they critically depend on for nutrition. They are, though, at amateur level with regard to the dependency on ecosystem. There are flowers without leaves altogether during their apparition. Many are called mycoheterotrophic plants. I recently encountered them in forests of our prefecture.

I found all of these plants without leaves have ghostly feature. Their entire body is white, or transparent. At a first glance they could be mistaken for mushrooms. But inspecting them closely, they certainly have flowers with petals, or petal like calyces. They are completely dependent on the underground network of fungi that can transfer nutrition made by the nearby photosynthesising plants. Another common thing among them is they are quite precarious plants. Say, this year we find it in such-a-such place, but it does not guarantee we can meet them at the same place next year. In this regard, those orchids I talked last week have more stable home and we can meet them at more-or-less the same place year after year. Compared to that, it’s like a news flash when we meet mycoheterotrophic plants in a forest. “Look! We can find them this year!!!!” Here are the photos for some of such plants found in Kanagawa Prefecture.

Monotropa uniflora. The photo is near max for the opening of this flower. Its leaves are degraded to scale-like features on its white stem. It comes out from the ground around mid-July, flower to procreate, then bear a so-so hard fruit that will drop near its parent. It’s not in the family of orchid, but in pinesap family. As it is mycoheterotrophic plant the seed should stay near its parent where underground fungi can provide nutrition of survival, I guess.

Hitaeria sikokiana. It is the endangered species at CR level for 2020 Japanese list. It is said it likes natural forest of broad leaves trees. i.e. Its fungi loves such environment. Commercial afforestation with conifers destroyed its world of happy life, and now its survival as a species is at the critical stage ...

Cymbidium nipponicum. This is a photo in which they are still in buds. It’s in EN category for 2020 Japanese List of Endangered species. They still keep some green on their stem, but obviously their ability for photosysnthesis should be minimum. They are in the family of orchid ... so not only their adult version but also dust-like seeds need help from underground fungi for nutrition. It‘s very demanding plant for forests.

Phacellanthus tubiflorus. Its way of receiving nutrition could be a bit different from these flowers above. It has roots that intrude deep into the root of host plant and sucks nutrition directly from it. I guess fungi play some role in it, but I couldn‘t find a research paper that studies such possibility ... Only during the monsoon season of Japan, it comes out from the underground to have flowers like this. The rest of its life is underground attached to the other plant‘s roots. Comparatively speaking, people say it‘s not so picky about the host, but the condition of its survival as a species is not robust ... 2020 list of endangered species for Kanagawa Prefectue does not register it in the list but several prefectures designate it as NT species.

Lecanorchis nigricans Honda var. patipetala Y.Sawa

I noticed these plants may have evolved to utilize fully the environment to get nutrition, but their way of doing it is so demanding for forests. Maybe because of it, they are in the list of “endangered species.” … While I was meeting these curious plants in the forests, the world is going into more and more mess. In my neighbourhood, food prices are getting higher, and shortage of wheat and corn world-wide is affecting the price of bread et al. We’ve noticed we Japanese have very low food self-sufficiency. Ministry of Agreculture, Forestry and Fisheries calculated ours is only 38% in terms of calories ... similar for Shunran. We’re like mycoheterotrophic plants in Japanese forests, utilizing global environment fully and eating what we’ve imported from outside with a help of stable, fungi nope, global supply chain. It’s cozy way to eat while the ecosystem lasts, but once we’re dug up, or the environment is broken, like maritime blockade in the other side of the planet, we soon find we have a problem … Scholars call mycoheterotrophic plants have reached to cul-de-sac of evolution; they are so good at exploit a specific condition, but actually very vulnerable for envorinmental change. Open economy or not; that’s the question for these plants to obtain nutrition. And maybe so do we Japanese.

If you find environmental issues in Kanagawa Prefecture, please make a contact with Kanagawa Natural Environment Conservation Center 神奈川県自然環境保全センター

657 Nanasawa, Atsugi City, 243-0121
〒243－0121　厚木市七沢657
Phone: 046-248-0323

You can send an enquiry to them by clicking the bottom line of their homepage at http://www.pref.kanagawa.jp/div/1644/