Spring is a good time to think about buds. Most of us are familiar with buds on the branches of trees and shrubs because they’re easy to see – and at this time of year, they begin opening and exposing new leaves and flowers. Most prairie plants, however start their spring growth from buds at or below the soil surface.
Before I go any further, I need to thank Jackie Ott, who provided the background information and photo interpretation for this post. Jackie is a PhD candidate, and one of a group of researchers at Kansas State University who are working to learn more about the buds of prairie plants and the role those buds play in the ecology of plant populations. Just as the collective seeds in the soil beneath a prairie is called a “seed bank”, the buds beneath a prairie can be called a “bud bank”. Jackie and others are trying to find out how those bud banks work, and (among other things) how they help plants and populations respond to stress. I’ve enjoyed several opportunities to learn about buds from Jackie and her colleagues over the last several years, and will write a future post about some of what they’re learning about bud banks. In this post, though, I present a short introduction (with photos) on the belowground buds of prairie grasses and wildflowers.
Buds are essentially packages of plant tissue full of cells that can divide very quickly. They are usually protected from moisture, temperature extremes, and other damage by a thick waxy coating. All of the buds on grasses are located below ground, so all growth comes from there. When a grass is clipped or grazed off, it just keeps pushing the growth up from the original underground bud. Forbs start their growth each spring from buds located near or below ground too, but they can also grow “adventitious” buds at any point along their stems. When a forb is clipped, it can create a new bud near the clipped tip and restart growth from there. If it is clipped too close to the ground, it may start a new stem from a belowground bud instead of from an adventitious bud.
According to Jackie, more than 90% of the stems you see in a tallgrass prairie each year started as buds, rather than seeds, that spring. Buds allow the “parent” plant to provide nutrients to the new stem and support its growth – as opposed to a seed, which has a limited supply of food in its endosperm and then is on its own to survive.
If you dig up a prairie grass or forb, you can easily find the buds around the base of the plant. Generally, there are multiple buds – each able to grow into a new stem if/when needed. Those buds represent the ability of that plant to produce new growth each season, but also following a disturbance such as fire, drought, or intensive grazing, that forces the plant to restart its growth mid-season. The larger collection of buds among all the plants in a prairie represents the prairie’s “bud bank.” The capacity of that bud bank to respond during stressful conditions is one of the most intriguing parts of what Jackie and her colleagues at Kansas State University are researching.
All of the photos in this post were taken in an indoor studio.
Great post and great pictures. Here at OSU, Gail Wilson (K-State transplant) and many of her student are doing research on prairie bud banks. I’m going to forward this post to them.
I’m looking forward to learning more about the bud bank concept. Is the idea that many buds lie in wait for particular conditions, often for a long time?
You’ll just have to be patient! Yes, the basic idea is the same as a seed bank, but my impression is that the response is more predictable based on current plant composition since the chance of success for buds is higher than for seeds.
Nice post Chris! You do a great job of synthesizing information in to nice-sized nuggests. I always get excited when people think about buds! If you get intrigued by the idea of belowground buds, it is a lot of fun and easy to look for them yourself while you are working with plants this spring. Many of my friends have brought me weedy grasses and other perennial plants they have pulled from their yard to show me the buds they can find on them without even using a microscope.
Forbs and grasses can act pretty differently from each other in response to disturbance. As Chris mentioned, forbs often can produce adventitious buds on various parts of their plant body as needed (even on their roots!). But forbs also produce axillary buds at regular intervals along the stem as they grow aboveground(these are the ones that you always see in the leaf axils, etc on your beautiful wildflowers). So when forbs are partly eaten by an herbivore, either an axillary bud or an adventitious aboveground bud can respond.
Can’t wait for Buds Part II!
Nice to see that similar questions are asked on both sides of Arlantic! I study bud banks in Europe, focusing on a role adventitious buds. They are not so easily formed on various plant parts; they are especially formed on roots but only in about 10 % of plants (at least in Central Europe).
I am studying the below ground bud bank of the species Baikiaea plurijuga (Zambezi teak) on commercially harvested stumps 31cm and above in diameter with a view of manipulating the bud bank for vegetative regeneration of the species which is on decline in this region. This species has root collar bud buried 60 to 80cm below ground. Del Tredici classifies these buds as suppressed bud. You classify such buds as dormant.. May I have your comment.
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