Monday, February 22, 2021

Googly Time Machine: Google Street View as a way to see the spread of invasive species

Photo by Dan Clark, USDI National Park Service,

I was looking at the distribution of an invasive grass species in Florida called Neyraudia reynaudiana (Burma Reed grass) in EDDMaps when I became interested in whether I could view some of the specimens that were in roadside right-of-way by using Google Street View.

This species is a very tall (up to 5 meters) showy grass that looks superficially from a distance like Phragmites australis. It is a threat to the pine rockland communities in South Florida, creating monocultures that significantly increase fire frequency and occurrence (Fusco et al, 2019).

I used EDDMaps to find some clusters of this species next to the Navy Wells Pineland Preserve in Miami-Dade, and viewed the area using Google Street View. There did not seem to be anything at the exact coordinates listed in the report, but I moved around the place and suddenly found specimens close to the intersection of SW 192nd Ave and SW 352nd Street.

The interesting thing is that Google Street View has a feature which allows you to view the same spot across the years, and I used this feature to view the same location all the way back to 2008, when Google Street View itself was only 1 year old.

It was amazing to see how the area seemed pristine in 2008 and 2011, only to suddenly be infested with rows of  N. reynaudiana by 2016!

It seemed that the vegetation closer to the road had either died or been removed (whether due to the grass itself or to some other natural or artificial event), and in their place the invasive grass had taken over. Instead of a tangled web of trees and shrubbery, by 2016 many of the images showed a more open and airy scenery.

I placed the images side by side in order to compare them better, and I have to say that following the spread of invasive species using high level distribution maps is quite useful, but being able to view the past and see how the species spread on the ground gives the process an immediacy and drama that cannot be matched.  

Literature Cited

Emily J. Fusco, John T. Finn, Jennifer K. Balch, R. Chelsea Nagy, Bethany A. Bradley. Invasive grasses increase fire occurrence and frequency across US ecoregions. Proceedings of the National Academy of Sciences, 2019; 201908253 DOI: 10.1073/pnas.1908253116 

Friday, February 12, 2021

Winter Bamboo Shoots: A Grassy Delicacy for The New Year of the Ox

When someone talks about bamboo, the first image that may crop up would  be of pandas in the wild. Some people who grow bamboo for its beauty may also pipe in that it has many horticultural uses. And for many, this versatile grass is well known as a building material, and is used to make not only housing facilities and various equipment, but is also a major component of kitchen utensils such as chopsticks and chopping boards. Some people have even created bamboo toilet paper

I was shopping at a Chinese supermarket a couple days back when I chanced upon an example of one other use for this versatile group of plants. Nestled next to a wall was a bin overflowing with whitish conical bamboo shoots! More specifically, they were the tips of bamboo shoots called "Winter Bamboo Shoots", which a quick google search said are dug up and cut during winter, even before the shoots have a chance to emerge into the open air. Each of the shoot tips was fat and heavy, and at $6.99 per pound (or more than US $3 per kg), they were not exactly cheap. 

Today marks the beginning of the Year of the Ox, a change from the unlucky Year of the Rat, and if ever there was a time to celebrate the turning of a season, then it would be now. So thinking, I bought one of the shoots, and today we will be preparing it for dinner using a recipe that I found in the New York Times. I posted the recipe below, and I look forward to having my first taste of bamboo ;-) 


1 tablespoon dried shrimp

1 teaspoon cornstarch

2 tablespoons chicken stock

2 cups julienned winter bamboo shoots (see note)

1 cup peanut oil

2 teaspoons rice wine

2 tablespoons chopped chives

½ teaspoon sugar

 Salt to taste

1 teaspoon sesame oil


  1. Pour boiling water over shrimp and soak 30 minutes. Drain and chop finely. Set aside.
  2. Make a paste of the cornstarch and a little chicken stock; stir in remaining stock. Set aside.
  3. Rinse and drain winter bamboo shoots. Using julienne blade of a food processor, process bamboo shoots. Dry well in a cloth towel.
  4. Heat oil to 375 degrees F. Add bamboo shoots and fry 5 to 7 minutes, until bamboo begins to turn golden. Drain off all but one tablespoon of the oil and set aside bamboo to drain.
  5. Add shrimp and stir-fry in the remaining tablespoon of oil.
  6. Add rice wine, chopped chives, sugar, salt, sesame oil and chicken stock mixture.
  7. Return bamboo shoots to mixture and cook until liquid has been absorbed.

Wednesday, February 10, 2021

Curious Critter #2: Sporobolus discosporus

Sporobolus discosporus (c) Richard Gill

This amazing looking grass is from Africa, where it was first recorded in 1841. The author of the image notes that it is a tiny species, around 5 cm across, and is found normally growing in very shallow soil on rock sheets. Mr. Johan Volstruis Combrink also notes that the species is part of the ecological process in the Bankenveld Grassland of the Witbank Nature Reserve in South Africa.

This little jewel looks almost like some aloe, and not a grass, and it would be really fantastic to see this in the wild. However, google searches show almost nothing about this species, especially ecological data, which again emphasizes the fact that there are so many fascinating species out there that we know next to nothing about.

Sporobolus discosporus (c) Richard Gill

Unfortunately, more and more plants are landing in the threatened bucket, and once these species are lost, then there is nothing to bring them back again. Let's hope that this jewel of a grass is not one of those species that is lost forever, even before we manage to read its story.

Click here for the species description from grassbase.

Click here for local distribution data.

Sporobolus discosporus (c) Richard Gill

Saturday, February 6, 2021

When do grasses break winter dormancy?

A, gerardii cultivar shoots growing with snow banks in the background

It's always a minor sort of miracle to me when Spring comes and the grasses that have overwintered by going into dormancy burst into new growth. This is especially true for the warm season grasses like Imperata cylindrica (Japanese Blood Grass, aka Cogongrass), Miscanthus sinensis, and Panicum virgatum, which "die back" completely during the cold season and re-emerge as new shoots. Last year, I noted down this process in late April, and I expected the same timing this year.

I had bought some native ornamental grasses during Fall, and I had been keeping them in my garage in order to lessen the possible stress of the pot bound plants due to extreme cold weather. Because I also store my tropical aroids in the same garage, I added a lamp that switched on every night for about 5 or 6 hours. The grasses were kept slightly away from the lamp, but they nevertheless must have gotten some illumination. Temperature in the garage was around 11-12 C.

A week or so ago I was surprised to discover that one of the Andropogon gerardii cultivars ('Blackhawk') had suddenly produced new shoots. This was unexpected since it was only late January, and in fact it snowed outside a few days later. Such early and premature breaking of dormancy normally would be a problem for the grass. Above ground shoots that had been prematurely produced could be killed by any sudden cold.  

I can only surmise that the warmer soil temperature in the garage might have caused the premature awakening of this particular cultivar. Triggered by the warmer temperatures, the grass had used its carbohydrate reserves to push out the culms. which caused me to wonder what would happen if global temperatures on average continue to rise. Would more and more grasses and other plants in colder northern climes break dormancy earlier during the year?

Some researchers did some experiments to answer this question. They took dormant Panicum virgatum (switchgrass) and Spartina spectinata, both of which are being studied as possible sources of biofuel, and grew them under ambient lighting, but with temperatures significantly higher than normal (Guo et al, 2017). 

They found that both species grew prematurely under the warmer soil temperatures, but the shortening photoperiod from early Fall to late Fall was confusing. They both ceased to grow, with P. virgatum maintaining the shoots above ground in a static condition, but S. spectina allowing the shoots to die back.

The result of the experiment confirmed the importance of photoperiod to the early growth of grasses after winter dormancy, and hinted that warming global temperatures might cause problems for grasses and other plants that break winter dormancy prematurely. The depletion of carbohydrate reserves in the rhizomes to power the new shoots, only to see these new shoots die due to sudden cold temperatures, might affect total biomass production and the overall fitness of the grass during the growing season.  

Literature Cited

Jia Guo, Arvid Boe, Do-Soon Kim, D.K. Lee. Growth and Development of Two Perennial Grasses in Ambient Light Conditions during their Natural Dormant Period. Crop Science, 2017; 57 (4): 2213 DOI: 10.2135/cropsci2016.09.0823