The Quiet Branches

Last week, I wrote about the marine plant, Zostera marina (Also covered on The Global Plant Council Blog by Sarah Jose), a rare plant that has adapted to living completely under the sea. This plant would have to re-evolve some traits to make the transition back to land (e.g. pores on the leaves to enable gas exchange).

Lead author of the Zostera genome paper Jeanine Olsen of left a comment to highlight a few things about the ecology and it’s importance in the environment:

…what I’d like to add is that seagrasses are being lost worldwide due mainly to coastal development and habitat loss, pollution and overfishing (e.g., the Baltic). Given the ecosystem services these underwater meadows provide, their loss is not trivial. Google seagrass watch for instance to see what’s happening in Australia. Google seagrass/images and see how beautiful and diverse they are. They keep the water clear, provide nurseries, erosion control and so on.

[Editor’s note: Do take Dr. Olsen’s suggestion to Google seagrass and check out some picutres. The meadows look so tranquil (even if that isn’t really the case). I think it would be amazing to experience one in person]

And how seagrass meadows are on par with coral reefs and tropical rain forests:

In terms of productivity, they are in league with coral reefs and tropical rain forests. In terms of carbon sequestration (in accordance with the DOE-JGI mission, which was one of the criterion for sequencing), they are much more effective than forests..So plant a seagrass rather than a tree (one might say).

The rest of her comment is worth reading too as it highlights some of the next steps for Zostera and just how the researchers will use the genome to keep exploring marine plant evolution, physiology, and conservation.

A quick Google search of ‘Australian Sea grass’ turned up the page of the Australian Institute of Marine Science noting that Australia is host to 30 of 57 total species of seagrass that can be found around the world and that they are under threat from habitat loss caused by trawler’s nets, agricultural and urban runoff that clouds the water, and dredging of seafloors. Similar threats are happening to seagrass around the world too. As Dr. Olsen noted, these are amongst the most productive ecosystems in the world and losing them is akin to losing a coral reef or tropical rainforest (both of which are also under strain worldwide too). And though seagrasses may well be one place to sequester carbon, like much of life, they can be negatively impacted by climate change too. For instance if sea levels rise too quickly for the to keep up with where the new shorelines are, that will cause further overall loss.

As robust and resilient as life on Earth is, it is also vulnerable in a lot of ways and has never faced the multi-pronged degradation of the environment that humans have set in motion.

On March 10, In Defense of Plants shared a story on his Facebook page about a new plant species discovered in Japan. The plant is Sciaphila yakushimensi  in honor of the island where it was discovered. Like Zostera and other seagrasses, it belongs to the order Alistimatales, though it is on a separate branch of the tree. To quote from In Defense of Plant’s Facebook post: 

Sadly, its native forest is under constant threat of logging. Much of this region remains unprotected.Since mycoheterotrophs like S. yakushimensi rely on an intact forest capable of supporting its host fungi, any disturbance that threatens the forest can spell disaster for these parasites. Far from being a detriment to the forests in which they live, parasitic plants like S. yakushimensi can serve as a very important reminder of how crucial it is to preserve entire ecosystems rather than single species.

S. yakushimensi is a parasitic plant. It makes its living getting nutrients from fungi in the soil. The only time the plant is observed is when it flowers. Because it lives off of soil fungi, it is reliant on the trees of the forest that supply the fungi it parasitizes with sugar. Unfortunately, the forest is under threat from logging. It’s possible that this plant would have remained completely unknown if the forest had been leveled before it was discovered.

I bring up this story because it demonstrates just how amazing evolution is. From an ancient ancestor, the Alistamatales have (in part) evolved into seagrass and a parasitic plant. And humans benefit from and threaten their diverse environments.

Another monocot (the broad class that seagrasses and S. yakushimensi belong to) on my mind that is also under threat from climate change is the iconic Joshua Tree (Yucca brevifolia). Due to rising temperatures, the low desert may not be suitable habitat for Joshua trees anymore. In fact, there are few, if any young plants in some parts of the desert.

Joshua Trees live in the Mojave desert in the Western United States. They are alien looking plants that are a keystone species of the desert. They provide habitat to many animals, including their exclusive pollinator, a species of yucca moth. It is interesting to note that another species of Yucca has acquired a second pollinator, not just a yucca moth, but that is not the case for The Joshua Tree, though the moth and plant drive one another’s evolution.

There is a group of scientists crowd funding right now to sequence the Joshua Tree Genome (Full disclosure- this is a project centered at my undergrad institution, Willamette University– I am a backer of this project). Willamette is a small liberal arts college in Salem, OR with a heavy focus on teaching. And this project will involve several Willamette students.

They also have a number of partners supporting the project including collaborators at The University of British Columbia, The Univeristy of Georgia, and The Donald Danforth Plant Science Center. Similar to the Zostera genome, The Joshua Tree genome will open up new avenues of research and ideally provide strategies to conserve these amazing plants. I encourage you to go check out the Joshua Tree Genome Project Blog and learn even more about Joshua Trees and what the scientists have planned. And consider become a backer (there is a competition for highest number of backers by March 16 amongst several schools, the prize being a $2000 bonus to the crowdfunding project with the most backers- even $1 makes you a backer). The overall campaign has 11 days left.

There are no guarantees that the Joshua Tree genome will save the trees, but it will land us new knowledge and have yet another plant’s genetic legacy stored in a place other than the organism itself, which can be useful in its own right.

I hope by highlighting these 3 plants, I’ve brought climate change and other environmental impacts of humans on plants to your front door. Taking action to address environmental issues (think of it as keeping Earth suitable for human life) will not only help us, but also keep thriving ecosystems alive and well. It’s an investment in Earth, the only home we have ever known and where we are presently stuck. We may as well help plants put down good roots.