Sejarah Poaceae
"The Story of Grasses - Celebrating Our Grasslands and other Open Ecosystems"
Tuesday, October 29, 2024
Wednesday, October 23, 2024
Sunday, October 20, 2024
Thursday, October 17, 2024
Saturday, February 10, 2024
New website is up but a work in progress
It took awhile as I had to get use to the new system, but the new website is up, though a work in progress. I still need to work on the design, and I still need to add way to subscribe and to get the feeds up.
Nevertheless, I look forward to continuing our journey into the world of grasses and grass ecosystems.
Saturday, January 13, 2024
Celebrating in a new and better website
I've been busy with life this past holiday month, and have been working on some writing, including a new article about the awesomely quirky Orcutt grasses for a magazine, but I'll be moving the website to my own server starting this February.
It's been great here in googleland, but I want better control of the site and the only way to do that is to migrate it to something that I can fully control.
After awhile, perhaps the new site will eclipse this old version, much like the newest invader in Florida above (Saccharum spontaneum) has started to overshadow the less showy Cenchrus purpureus (with the yellowish inflorescence in the background and foreground).
I will certainly try my best to continue to celebrate the grasses and the amazing ecosystems that they create, and I will always push forward the idea that sharing information about their value is one of the best ways to preserve these ecosystems. Knowledge is power, as they say.
More information later.
Note: Wild sugarcane (S. spontaneum) is a very tall (3-4 meters) dominant species in grasslands in Asia (I have seen them a lot in the Philippines for example), and has recently been officially declared present in the United States (in Florida). The picture above was taken in Lake Okeechobee, FL.
Thursday, November 30, 2023
Cruising the Ocean and a Sea of Grass.
Looking out at the ocean from the balcony of a Celebrity cruise ship |
We took a cruise this month, and we had a balcony that allowed us to watch the ocean from our stateroom. I spent many hours just sitting and reading and watching the sea go by, and marveling at the immensity of the view outside.
Looking out at the ocean always makes me feel small, almost insignificant. Its vastness, its seeming permanence, puts many things into perspective. Paradoxically, it also imbues me with a deep serenity that makes cruising a favorite way to relax in between bouts of work.
In almost the same way, looking out across vast grasslands gives me the same feelings. There is this spot nearby with a large field of grass where I sometimes park my car and just spend an hour or two reading. The panorama might be a colorful green or a rust red instead of the dark blue of the seas, but the solitude and the tranquility of the landscape never fails to make me happy.
I sit and read by a sea of grass |
Field of Reeds (Moon Knight, Marvel) |
The endless fields of wheat in the film Gladiator |
Dan Simmons' Hyperion and The Sea of Grass |
"My God," breathed Brawne Lamia.
It was as if they had climbed the last hill of creation. Below them, a scattering of docks, wharves and sheds marked the end of Edge and the beginning of the Sea. Grass stretched away forever, rippling sensually in the slight breeze and seeming to lap like a green surf at the base of the bluffs. The grass seemed infinite and seamless, stretching to all horizons and apparently rising to precisely the same height as far as the eye could see. There was not the slightest hint of the snowy peaks of the Bridle Range, which they knew lay some 800 kilometers to the northeast. The illusion that they were gazing at a great green sea was nearly perfect, down to the wind-ruffled shimmers of stalks looking like whitecaps far from shore.
"It's beautiful," said Lamia, who had never seen it before.
Barring aside the improbability of windwagons being borne on the tops of masses of plants (no matter how strong the culms), the idea of travelling above vast seas of grass to distant lands is irresistibly attractive, and even romantic. Perhaps such adventures will be possible in far-off places with less gravity than ours, but for now, I'm content to just spend time by my decidedly more earthly landscape.
*sighs and goes back to reading Hyperion, while gazing at the dark brooding masses of clouds now gathering above his Sea of Grass*
Where's that windwagon? |
Saturday, November 25, 2023
The Muscovy Duck Intervention
Mounds of Zoysia matrella (Manila grass) along banks of canal leading to the sea |
I was walking along the main thoroughfare Lloyd G. Smith Boulevard in Aruba last week when I came upon an odd sight in Wilhelmina Park.
The tiny Zoysia matrella (aka Manila grass) is a common turf grass in tropical countries, where it is sometimes known in the horticultural world by the incorrect name "Zoysia tenuifolia". It is in the subfamily Chloridoideae and forms thick beautiful sod using both aboveground stolons and underground rhizomes.
Muscovy duck strutting in Wilhelmina Park, Aruba. |
Zoysia matrella flowerheads |
A really weird looking bird had suddenly appeared, and it was strutting back and forth close to me in what I took to be a threatening manner. In many ways it looked like a regular duck, but it had a red warty face that only a mother could love.
Zoysia matrella flowerhead showing white anthers and purplish stigma |
It was also hissing like a snake, and bobbing its head up and down rapidly. I stepped warily away from it and prepared to defend myself, but the bird simply continued to look at me and bob its head up and down.
Did it have some nest hidden near the river bank? Was I somehow trespassing into its territory?
What I took to be the remnants of duck feathers next to Z. matrella flowerheads |
I wondered too whether the duck had been using the mounds as a nest, because I found remnants of what seemed to be bird feathers on the grass surface. Perhaps I really was invading its turf (no pun intended), and so I immediately vacated the area and went back to the nearby path.
Thursday, November 23, 2023
Buffelgrass invasion in the ABC (and why people should be worried)
Clusters of Cenchrus ciliaris (buffelgrass) with whitish flowerheads in Aruba |
To say that the southern Caribbean islands of Aruba, Bonaire, and Curacao (which are fondly called the ABC islands) have a somewhat small number of grass species would be accurate, and these include quite a few invasive species that are also prevalent in many other Caribbean countries.
During my visit to these islands last week, one of the more prominent invasives was Chloris barbata (subfamily Chloridoideae), its digitate inflorescence a common sight in disturbed areas. This species was present not only in the most urban of areas, but it popped up even close to the beaches.
Chloris barbata in Bonaire's Te Amo beach |
But a more ominous invasive in the ABC is Cenchrus ciliaris (of the subfamily Panicoideae, syn. Pennisetum ciliare, aka buffelgrass in the USA), which has been notorious for its ongoing threat to the iconic Saguaro in the southwest USA. This species crowds out native vegetation, and because it exists in dense clusters, it can create continuous fuel sources for fires. Such fires are deadly to the Saguaro and other desert plants, which have not evolved to live through it.
Cenchrus ciliaris near Mambo Beach in Curacao |
C. ciliariis is from Africa and parts of the Middle East and Asia, and it was brought to the USA as a source of cattle forage and erosion control. It can tolerate arid conditions, and is thus a good fit in the semi arid environments of the ABC islands.
During a bus excursion around Aruba, I saw large fields of what I took to be this species beyond the main urban areas. But even in the very midst of the few towns that dotted these islands, I found C. ciliaris hiding in plain sight.
Cenchrus ciliaris in middle of road in Curacao |
In Curacao, rows of this grass lined the canals emptying into Mambo Beach, and I even found it in the middle of a street in front of the Maritime History Museum!
The presence and continued proliferation of this species in the islands should be worrisome to authorities and to the inhabitants. The history of C. ciliaris in the American Southwest has demonstrated its ability to overwhelm native habitats, and the recent huge fires in Hawaii that killed hundreds is a warning about what can happen if people are surrounded by fire-prone invasive grasses. The fact that buffelgrass has been recorded as burning up to 871 °C, and indirectly recorded to temperatures of 900 °C. (MacDnald et al, 2013), is testament to its potential threat to the environment and people.
Masses of flowering C. ciliaris in Aruba |
Friday, November 10, 2023
Help pass the North American Grasslands Conservation Act of 2022
A storm is passing over the nation's grasslands (image by Christian Collins, Wikipedia) |
What is the North American Grasslands Conservation Act of 2022?
In 2022, Senators Ron Wyden, Amy Klobuchar, and Michael Bennet introduced a bill which would take bold actions to conserve and restore native grasslands in North America through voluntary, science-based efforts. This will help conserve grassland ecosystems in order to sequester carbon, prevent wildfires, and stop the further loss of wildlife. It will also address and support the interests of various stakeholders, including ranchers, farmers, Native American Tribes, sportsmen and sportswomen, rural communities, and others.
Why is this needed now?
Grasslands, including sagebrush shrub-steppe systems, are some of the most threatened ecosystems in North America and in the world. In 2021 alone, more than 800,000 ha (2 million acres) of native grasslands in the Great Plains and Northern Great Plains were converted to agricultural cropland (mostly wheat and corn). This area is significantly larger than the entire state of Delaware, and it was lost in just a single year!
If we are to save these open ecosystems that are essential wildlife habitats and critical for rural economies and carbon sequestration, then we must act now.
What will it do?
The Act would initiate the following actions in support of its overarching goal to conserve native grasslands:- Create a North American Grasslands Conservation Council
This council will help develop an overall conservation strategy, as well as recommending and selecting specific grassland projects. It will be composed of Federal, State, Tribal, and conservation organizations, in addition to different farming, ranching, and grazing groups.
- Establish Regional Grasslands Conservation Councils
These numerous councils will give recommendations, support, and advise on grasslands projects for their specific regions. They will be composed individuals from regional conservation organizations, ranchers, Tribes, and State wildlife agencies.
- Formulate a North American Grasslands Strategy
The Director of the US Fish and Wildlife Service will coordinate with the councils to develop an overall strategy to conserve grasslands, including: - identifying areas at high risk for grassland habitat loss
- spotlighting conservation areas with high potential
- identifying at risk populations of grassland obligate bird species
- establishing specific goals for enhancing grasslands
- Establish a grant program for grassland conservation
This will support projects for conservation, restoration, management, and education activities, and can include:- prescribed burns
- management of invasive species
- grazing management training programs
- projects that conserve intact grasslands at risk of conversion to cropland, residential or commercial development
- Support native seed crop research
The Secretary of the Interior and the Secretary of Agriculture will carry out research relating to native seed crop systems, in order to help improve our understanding of native seed technologies and promote adoption of native seed cropping systems on rangelands.Some examples of such research include:- agronomic research to improve the understanding of native plants as seed crops
- research on plant seed physiology to improve seed quality, storage, and seeding success in the landscape
- development of best management practices and technologies for seed production, seed storage, and reseeding success in the environment.
- Establish a program to study regenerative grazing
The Act will establish a program to holistically study the ability of regenerative grazing practices on Forest Service and BLM lands to mitigate climate change. Some regenerative grazing practices include:- silvopasture
- season of use
- forage and biomass management
- range monitoring methods
Using such practices on test and live projects can then allow assessment of their effects on soil health, carbon sequestration, watershed biodiversity, and air quality
This strategy would not exist in a vacuum, but draw on existing local, State, Tribal and regional conservation plans and wildlife action plans.
Tuesday, October 31, 2023
An Enchanted Hike Through the Enchanted Mesa
Tall flowering grasses line the path |
I could spend tons of posts on the beauty that we saw when we stayed in the Boulder, Colorado area this last summer, but one of the more notable periods of our stay was when many of the so-called wheatgrasses were in flower.
The Enchanted Mesa trail in the Flatirons hiking area is considered a moderate trail, but I remember it was relatively easy and flat. You also get some good spectacular views along part of the way.
The arching flowerheads of T. intermedium |
Red Rocks Trail in July |
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Sunday, October 29, 2023
The Ancient Fire and Grazing Grasslands of Madagascar
Two types of grassland, side by side |
Whenever I take a walk outside, I am always struck by how various grass communities (whether natural or artificial) seem to have very distinct physical appearances. In today's suburban world of course, the most visible grass communities are the lawns that grace many homes. They're composed of grass species that are short and adapted to lots of mowing. But go to some nearby natural area like a pine and wiregrass savanna, and now much taller grasses dominate.
The grass species that are found in each type of community can vary significantly, and this difference was a topic investigated by researchers in Madagascar. In this country, the vast old growth grasslands (which includes savannas) are in peril due to misguided afforestation efforts by some. This is because the common misperception (as in many other countries in tropical areas that were once colonized) is that these grasslands are the products of human activity and derived from areas that were once forests.
Cynodon dactylon, a major component of the grazing grassland. Yes, that's Bermudagrass, a common turf grass in the USA and elsewhere. |
In their study, they examined (1) whether some species were associated together more often than not to form a specific assemblage or community. They also looked at (2) the functional attributes of each species with regards to flammability, palatability and tolerance to fire and grazing. These were:
- Plant height - taller plants tend to be more flammable
- Leaf thickness - thicker leaves tends to be less palatable
- Leaf C/N ratio - leaves with higher C/N ratios tend to be more flammable
- Leaf shape - wide short leaves are preferred by grazers as more palatable, while long narrow leaves ignite easily and burn more intensely
- Plant bulk density - high bulk density grasses provide more forage per bite, whereas low density grasses provide more aeration for fires.
They found several fascinating and important things:
First, they found that, indeed, species tended to cluster together into distinct spatial assemblages. Some species tended to be found together with the same group of species more often than not, and only in certain locations.
Secondly, they also found that the species they studied in Madagascar could be divided into 3 distinct functional groups. The first functional groups showed adaptions for grazing, and are mostly short grasses with high bulk densities, and leaves that are short, wide, and thin. Many of these are mat-forming, using either rhizomes or stolons. The second functional group is adapted for fire, and is comprised of tall bunched grasses with thicker leaves, low bulk density and low leaf width to length ratios. They also found a distinct and third functional group that were intermediate between the two extremes.
A fire adapted grass (Imperata cylindrica) |
Finally, and most importantly, they found a relationship between the spatial assemblages and the functional groups. The functional group of a species influences which assemblage contains it (see table below).
Solofondranohatra CL et al, 2020 |
Sunday, October 22, 2023
Creepy Corn Day (aka Halloween)
Corn stalks for sale at Lowes in New Jersey |
It's that time of the year again when spooky shenanigans slither into the normal daily lives of people. It's when kids in costumes defy the odds and gather candies from strangers, and the Simpsons treat us to another round of entertaining stories about really weird stuff.
Yes, it's Creepy Corn Day (aka Spooky Corn Day, aka Halloween), which should be that celebration's official name, given that so much of the traditions associated with this day are related to the species Zea mays (corn/maize).
This was the thought that came to me while I was walking outside a Lowes in New Jersey last week and I saw another bunch of dried corn plants for sale. It made me wonder about all the other things during Halloween that involved this grass.
Corn Shucks
The dried bunches of corn that I saw are called corn shucks, and they were traditionally used by farmers during the end of the harvest to dry out the corn and to clear land for other plantings. The dried stalks were later used for bedding and feed for animals, and the corn itself was milled. During modern times, mechanical harvesters have obviated the need for this, but their common use in the past made people associate them with Fall and Halloween. Plus, they truly do look kinda spooky.
We're gonna get ya! |
Candy Corn
I was not so familiar with this particular Halloween tradition, but it seems is very popular with kids. It's a type of candy that boasts a whopping 28 grams of sugar per handful, and is made out of various ingredients, including (you guessed it!) corn syrup. It is the most popular candy treat during Halloween in many states, and in 2019, it was estimated that more than 95% of holidays shoppers bought some of this confectionary. More than 9 billion of the candy is produced each year!
The candy seemed to have been first created by the Wunderlee Candy Company in Philadelphia in 1880s, but its popularity and association with Halloween did not occur until the 1950s, when the tradition of handing out candies to visiting children became popular.
Candy Corn |
Corn Mazes
The idea and implementation of plant mazes has been with us since ancient times, but the use of corn fields to create mazes during the Autumn was not started until the early 1990s.
In 1993, a man named Don Frantz was flying over a corn field when the idea came to him. It didn't hurt that he had been involved in other creative endeavors, including shows in Broadway and the Super Bowl halftime show. Frantz and another man named Adrian Fisher created the first corn maze in Lebanon Valley College in Annville, Pennsylvania. They named it "The Amazing Maize Maze", and the maze was modeled in the shape of a dinosaur named "Cornelius the Cobasaurus".
The popularity of corn mazes spread, and today they are another staple of Halloween...ahem...I mean, Creepy Corn Day.
Saturday, October 14, 2023
Following Buffaloes
Male flowerhead of Bouteloua dactyloides (Colorado) |
In 1977, a movie called Star Wars was just starting out on its path to becoming one of the most successful science fiction franchises in history. Marty McFly had yet to drive his DeLorean back to the future; Arnold Schwarzenegger was a relatively unknown bodybuilder whose metamorphosis into the Terminator was years into the future, and even E.T. had no need to phone home just yet.
Male flowerheads of Bouteloua dactyloides (Colorado) |
In this same year, in a university town in New Jersey, plant clippings from a garbage bin that was being emptied by trash collectors accidentally fell onto a lawn of Kentucky Bluegrass (Poa pratensis). The clippings had come from a nearby Rutgers University greenhouse that was housed in the Nelson Biological Sciences building. A grass species from the high plains of Oklahoma and Kansas was being grown there for turf studies, and its introduction into the heavily trampled and disturbed grounds of the Rutgers Busch Campus was in hindsight a fortuitous event (Quinn, 1998).
Front lawn of Library of Science and Medicine at Rutgers Busch Campus. Red arrows point to B. dactyloides clusters |
Forty six years later, I knelt on the same grounds in front of the next door Rutgers Library of Science and Medicine (LSM) building and examined tiny male flowerheads of Bouteloua dactyloides (commonly called buffalo grass in the USA). They marked the occurrence of the same plant(s) that had escaped almost five decades earlier, and their expansion and spread using both stolons and seeds moved me. I felt a sense of being connected through time by this humble native grass to that past accident so long ago.
It was relatively easy to determine the extent of the spread at this time of the year. The species starts to brown earlier during autumn, and it stood out against the still darker green masses of other turf grasses. I could see clearly that it was now present on different lawn areas that were separated by concrete paths, and that some of the irregularly shaped clones were quite large.
Mobile phone pic of male flowerheads of Bouteloua dactyloides in lawn of Library of Science and Medicine, Rutgers University Busch Campus. |
I noted the GPS coordinates and measured the sizes of the clusters that I could ID as B. dactyloides. Many were vaguely round, oval, or rectangular in shape, with diameters of half a meter for the smaller ones, and sizes that approached bedroom size for some of the larger ones.
Room size cluster of Bouteloua dactyloides (light brown area) next to Rutgers Library of Science and Medicine |
The survival of the original plant for almost half a century is notable, because B. dactyloides has been touted as a low-maintenance, drought tolerant, and native alternative to the usual European grasses that dominate the northeast lawns in the USA today. I myself considered its use on my own lawn in NJ at one time some years ago.
Unfortunately, its intolerance to shade and its inability to be competitive in rainy wet areas has always raised questions as to whether it would be a successful replacement to the proven imported turf grasses. In this case, not only had it survived for almost half a century, but it had managed to spread significantly against formidable opposition from forbs and other types of grasses such as P. pratensis. This helps prove that it is possible to use this species as turf grass and for erosion control in disturbed soil in the Northeast.
Female reproductive structure of Bouteloua dactyloides (Colorado) |
As an important aside, I know some people follow trees over time, but there are many herbaceous plants that can exist for very long periods, and it is just as rewarding to follow their lives over time. In fact, the longest lived organism in the world is a herbaceous seagrass, which has been calculated to be 80,000 to 200,000 years old (Arnaud-Haond et al, 2012)! It is amazing to think how the world has seen so much change during that astounding duration.
In the same way, although spanning an exponentially shorter span, when I first laid my eyes on the spreading clusters of B. dactyloides in front of the LSM library a couple days back, I truly felt an emotional attachment to them. I studied at this same university in the 1990s, and I had likely passed by the same individual many times on the way to my studies. It made me feel the ticking of time with a more visceral emotion than mere objective contemplation, and it humbles me that this clonal individual might still be flourishing and thriving and growing when I'm long gone from the world.
Literature Cited:
Arnaud-Haond S, Duarte CM, Diaz-Almela E, Marbà N, Sintes T, Serrão EA. Implications of extreme life span in clonal organisms: millenary clones in meadows of the threatened seagrass Posidonia oceanica. PLoS One. 2012;7(2):e30454. doi: 10.1371/journal.pone.0030454. Epub 2012 Feb 1. PMID: 22312426; PMCID: PMC3270012.
Quinn, J. A. (1998). Natural Expansion of Buchloe dactyloides at a Disturbed Site in New Jersey and Its Implications for Turf and Conservation Uses. The Journal of the Torrey Botanical Society, 125(4), 319–323. https://doi.org/10.2307/2997245
Tuesday, October 10, 2023
Grasses all day, every day, and grasses ever after, amen!
My life, as well as the lives of billions of other people, are intertwined with grasses...we are touched by them....from the time we wake up in the morning, to the time we sleep at night.
This was what I tried to convey during a talk with Matt Candelas of In Defense of Plants.
In my case, when I wake up in the morning, I (like literally billions of other people around the world) encounter members of the grass family, or derivatives of it, throughout the day.
The first thing I do in the morning is eat a bowl of oatmeal, and oatmeal of course is from the grass Avena sativa.
When I eat my bowl of oatmeal, I put some sugar into the mix of fruits, and around 80% of sugar in the world is derived from a grass, sugarcane (Saccharum officinarum).
I walk out to my car, and I'll see suburban lawns stretching to the horizon, and the turf grass of course is a mix of various grass species. In Florida it would be Stenotaphrum secundatum (St. Augustine grass), Paspalum notatum (Bahia grass) and maybe Cynodon dactylon (Bermuda grass), while in the Northeast you get various mixes of Poa pratensis (Kentucky bluegrass), Festuca spp, and Lolium spp.
Such species are what people normally think of when you mention the word "grass" to them. Ornamental grasses also fall into this category of grasses that are used in landscaping.
When I drive my car to work, the ethanol in my gasoline tank is likely as not made from Zea mays. In fact, around 40% of all corn production is used as bioethanol!
During lunch, I might go out and get a burger, and where would that be without the bread that frames the delicious ingredients between them? Bread of course is from a grass that we call wheat, (Triticum aestivum and its ilk).
Maybe I also eat some snacks for lunch, and if you are brave enough to look at the ingredients of your candy or chips, you'll probably find something called high fructose corn syrup in it. This is a very common ingredient of packaged foods, because it adds to the sweetness of the food, and this is of course derived from a grass that we already mentioned above, Zea mays (corn/maize).
In fact, if you live in the USA, your body is probably mostly derived from that single grass species. Here is a great documentary that explores in some depth the ubiquity of Z. mays in American life.
Finally, during some part of the day, I'll probably eat rice (Oryza sativa) during either lunch or dinner (and sometimes breakfast too!). Rice is, of course, one of those grasses that have been essential in the creation and and molding of entire civilizations (which I'll look into next time).
Friday, September 29, 2023
How I do botanical backgrounding in photographs
Cynodon dactylon (Bermuda grass) in Parque del Amor, Lima, Peru. The beach is down below a cliff, and you can see the waves as they rush to shore. |
Note: I am by no means an expert at photography, so apologies for any mistaken notions I may have, but here are a few things I've learned.
I am a big fan of macrophotography, and I have been doing it for several years now.
But sometimes I want to show more than just the specimen, especially when the picture I am taking includes scenery that is well known or significant.
In this case, my goal is to have a sharp foreground showing the specimen(s), but with a soft blurry background that does not take away the scenery completely. In order to accomplish this, you need to create something called a shallow depth of field.
Bromus tectorum (cheatgrass) in foregound of Continental Divide scenery in Rattlesnake Gulch Trail, El Dorado State Park, Colorado, USA. |
Creating this shallow depth of field is more an art than a science, and it involves fiddling with various settings in your DSLR camera, as well as correctly positioning yourself and your subject. This includes:
1. Aperture
This refers to the amount of light that reaches the camera sensor, and the metric it uses is called the f-stop. The lower the f-stop, the greater the amount of light that reaches the sensor, and the shallower the depth of field (the blurrier the background).
For example, an f-stop of 3 means more light gets to the sensor, which creates a shallower depth of field than if the f-stop is 9. So using an f-stop of 3 would get you a blurrier background compared to using an f-stop of 9, all other things being equal.
Dactyloctenium aegyptium in foreground and our cruise ship in background (in Costa Maya, Mexico) |
2. Focal length
This refers to how wide your angle of view is, and it also affects the magnification. It is measured in millimeters (mm), and the rule of thumb is that the longer the focal length, the greater the magnification, the narrower your field of view, and the shallower the depth of field (the blurrier the background).
So, a focal length setting of 100 mm provides greater magnification, a narrower field of view, and a shallower depth of field than a lens with a focal length of 20 mm.
Bouteloua dactyloides (Buffalograss) in foreground of Buffalo Bill sculpture in Oakley, Kansas. |
3. Distance between camera and specimen
There are also things you can do beyond just fiddling with your camera settings to create a soft blurry background and a sharply focused subject. The distance you keep between your camera and the actual specimen also makes a big difference.
The smaller the distance between the camera and the specimen, the shallow the depth of field (the blurrier the background).
Sporobolus michauxianus (formerly Spartina pectinata) near Lower Bluestem Trail, Boulder, CO, USA. |
Putting all these factors together, the golden rule of botanical backgrounding therefore is:
In order to get a shallower depth of field (blurrier and softer background) while maintaining a sharp focus on the specimen, you need a lower f-stop, a higher focal length, and a shorter distance between camera and specimen.
Here's an example of how focal length, aperture, and distance to the specimen can affect the depth of field and how blurry the background gets using the same specimen and background.
In the first pic below, the specimen is Avena barbata, with the Moras Salt Mines in the Sacred Valley of Peru in the background. The f-stop used here is 8, the focal length is 20 mm, and I was standing relatively far away from the specimen when I took the pic. Notice how relatively clear the background is when compared to the actual subject of the photo. This makes the picture too "busy", and detracts from the focus of your photograph, which is the grass in the foreground.
Avena barbata (?) in the Moras Salt mines in the Sacred Valley of Peru |
Now compare that picture above with the picture below. This is the same specimen, but this time I am using an f-stop of 2.8, a focal length of 100 mm, and I am closer to the specimen. Notice how relatively clear the specimen is, but how blurry the background has become. Normally, I would not want a photo like this when I'm doing botanical backgrounding of my photo (too shallow a depth of field and thus too blurry in back), but it does illustrates how aperture, focal length, and distance to the specimen heavily influences the depth of field and the contrast between subject and background.
It also highlights how much of an art it is trying to get a good optimal mix between a too-clear background that steals focus from the subject, and one that is a completely unrecognizable blur.
Avena barbata (?) in the Moras Salt mines in the Sacred Valley of Peru |