What makes a plant a native?

I have been spending an awful lot of time indoors the last few weeks insulated from all this winter weather.  Work in the office involves quite a bit of data entry, navigating Excel worksheets, and preparing lab samples providing me with plenty of time to think about all the why’s, the what’s, and the how’s of our research. 

Today my mind is stuck on a what … Just what is a native plant anyway?

 A native Asceplias spp. better known as Butterfly Weed

I did a quick internet search and found the following definitions:

USDA Forest Service:

Native plants are the indigenous terrestrial and aquatic species that have evolved and occur naturally in a particular region, ecosystem, and habitat. Species native to North America are generally recognized as those occurring on the continent prior to European settlement. They represent a number of different life forms, including conifer trees, hardwood trees and shrubs, grasses, forbs, and others.

Federal Executive Order 11987:  

‘Native species’ means all species of plants and animals naturally occurring, either presently or historically, in any ecosystem of the United States.

U.S. Fish and Wildlife Service: 

Native. With respect to a particular ecosystem, a species that, other than as a result of an introduction, historically occurred or currently occurs in that ecosystem.

The United States National Arboretum:

A native plant is one that occurs naturally in a particular region, ecosystem, or habitat without direct or indirect human intervention. We consider the flora present at the time Europeans arrived in North America as the species native to the eastern United States. Native plants include all kinds of plants from mosses and ferns to wildflowers, shrubs, and trees. 

Did you pick a favorite?  What I see as common to all of these definitions is the designation, by humans,  of place and time.  A plant in its proper place has all that it needs to grow vigorously while fulfilling its role as food to some and shelter to others.  It is resilient to competition and predation, enjoys a reproductive advantage, efficiently uses water and nutrients, while functioning in a community that includes other plants, animals, fungi, soil, etc.  

Well, that is not so different than any one of us, native earthlings, now is it?

 A native Cirsium spp. in the sandhills of Georgia

 Allium tricoccum, better known as ramps, are a popular spring ephemeral in the mountains of N.C.

Lespedeza capitata in flower at one of our experimental gardens

Wiregrass planted!

We planted our final species in the common gardens this past week!  We now have 3 grasses (Sorghastrum elliottii, Schizachyrium scoparium, and Aristida beyrichiana/stricta), 2 composites (Pityopsis graminifolia/aspera and Solidago odora), and 2 legumes (Tephrosia virginiana and Lespedeza capitata).  

 Wiregrass plug trays lined up and getting rained on at SREC. 

Cold, wet, and dreary pretty much sums up last week for me.  Perfect conditions for our wiregrass seedlings, but only just tolerable for a southerner like myself.  Soil conditions at all 3 of our gardens were moist and cool.  We were drizzled on from time to time, but thankfully the predicted ice pellets never materialized.  Thank you TJ, Joan, Kate, Eric, and Shawna for all the help this past week!  

Kate and Eric carefully planting wiregrass plugs at SREC.

Planted wiregrass at PDREC.

A close-up of planted wiregrass plugs at PDREC.

Planted wiregrass at CREC.

A close-up of a wiregrass plug planted at CREC.

And this is what approximately 6 hours of planting looks like in a minute and a half...

Of smut and wiregrass...

During our native seed collections of 2010 and 2011, I really got an eye for spotting healthy plants and inflorescences with seed suitable for propagation.  There was plenty of time to refine those skills while walking literally hundreds of acres of longleaf pine woodlands.  In that time I also got an eye for spotting plants and seeds that were just plain not right.

A typical stand of longleaf pine and wiregrass at Carolina Sandhills NWR.

 The species that most piqued my curiosity was our native wiregrass (Aristida beyrichiana/stricta).  What I started to notice was a black dust on the seeds and stems of plants along with swollen greenish-black seeds.  Well, I asked around a bit and it didn't take long to find out what I was looking at.  A smut fungus and possibly some powdery mildew.  Now, a lot of folks had observed the smut on wiregrass in their longleaf stands, but nobody could tell me anything else about it.  

A handful of wiregrass culms with evidence of smut.

We hope to change that very soon.  Recently Dr. Joan Walker of the USFS's Southern Research Station initiated a research project with Dr. Julia Kerrigan, an Associate Professor of mycology at Clemson University, to find out just what this smut is and where it exists.

Black powdery spots and streaks on wiregrass seed. 

We hit the ground running in October and our technician, Inga Meadows, has already visited a dozen properties across the Carolinas and into Georgia.  This is an exciting new project that will hopefully shed some new light on wiregrass seed ecology and inform efforts to restore this important native grass to the groundlayer of longleaf pine forests.

A close-up of smut-infected wiregrass seed.

This infected seed will swell until it bursts open. 

Tracking phenology in our common gardens

TJ and I were back at our common gardens this past week observing the progression of flowering in our native species.  Phenology is the study of cyclical biological events, such as flowering, in relation to climatic conditions.  We collected data for Pityopsis graminifolia, Solidago odora, and Lespedeza capitata at each of our gardens.  Enjoy these images of what we were observing without all the heat and humidity of summer field work in the South.

A Pityopsis graminfolia flower being pollinated by a visitor.

When buds initially form on Pityopsis graminfolia they are green, but they soon turn yellow as they mature and expand into a flower.

A seed head on Pityopsis graminifolia.

One of our Pityopsis graminifolia plants showing the full progression of development from green buds to yellow buds to flowers to senesced flowers to seed heads.

A Solidago odora plant with green buds.

Yellow buds on a Solidago odora plant starting to expand into flowers.

Open flowers on a Solidago plant being pollinated.

Green buds on Lespedeza capitata.

Flowers just starting to expand on one of our Lespedeza plants.

Clusters of open flowers on a Lespedeza plant. 

Clusters of senesced flowers on a Lespedeza plant. 

We also enjoyed a visit from Clemson University professor Dr. Saara DeWalt and her student Lucy at our Sandhill REC garden.  They came out to collect leaf samples of Tephrosia virginiana for a genetic study to be conducted this fall.  More details on that part of our project later.

Hand collecting leaf samples of Tephrosia virginiana. 

Common Garden Update, July 2014

TJ and I were at our common gardens last week collecting data from 3 of our plant species.  We did some vegetative measures and started tracking the progression of flowering and seeding for each of those plants.  Thanks for all the help TJ, the gardens look good and most of our plants are thriving.

Pityopsis graminifolia

Solidago odora

Lespedeza capitata

And in honor of Dr. Seuss, here is our update:

Some are tall and some are short,
but we measure each one no matter what sort.

Measuring the height of a Pityopsis plant.

There are skinny and fat,
small plants and large, 
compact or bushy I don't know who's in charge.
Some have flowers and some do not.
We saw the whole range because we measured a lot.
Some are branchy and some are straight,
and some are all twisty, twiny like a braid.

Twisted stems at the base of a Solidago plant.

We want to track them, just how they grow,
the more data we collect, the more we can know.

Some of our Solidago plants are growing sideways most likely because they are top heavy along with the windy conditions at our garden.

Most are alive, but some are dead.
We can't let that get us down, we just keep going ahead.

Several rows of Pityopsis plants, there a dead individual next to a couple plants that seem to be dying back.

We make careful notes about each plant, their size, and stage of flowering.

Does the plant have buds?

Are there flowers open?

Have the flowers been pollinated?

These are just some of the things we are scopin'.

A flower bud on one of our Pityopsis plants.

A Pityopsis plant showing the full progression of flowering, from green buds to seed.

The top of a Lespedeza plant with green buds starting to show.

The top of a Solidago plant with newly formed buds.

A portion of a Solidago plant showing the full progression of flowering, from bud to seed.

That my friends is called tracking phenology,

we do that because we are crazy about biology!

We plan on measuring more plants in a hurry,

until all the flowers have bloomed and seed has dispersed in a flurry.

Spring time common garden update

We have successfully planted 6 of our native species in all 3 of our common gardens!  Two grasses (Sorghastrum elliottii and Schizachyrium scoparium), two composites (Pityopsis graminifolia and Solidago odora), and two legumes (Tephrosia virginiana and Lespedeza capitata).  Now, let's see if we can get them established.  

It has been surprisingly difficult to go from this...

Fabric, with irrigation, installed at Coastal REC in Charleston

to this...

Planted Solidago after approximately 1 month at CREC.

and this...

Planted Pityopsis after approximately 1 month at CREC.

Thus far, the grasses have only struggled along, but the composites are doing well at all of our gardens (as you can see above).  We will have to wait and see how the legumes do since we just planted them.

Sorghastrum seedling at PDREC approximately 5 months old and just weeded.

Solidago at PDREC after 2 months in the ground.

Pityopsis at CREC after 2.5 months in the ground.

Tephrosia planted May 14th at CREC.

Lespedeza planted May 29 at SREC.

Weeding will probably be the most demanding chore during this establishment phase of our common garden study.

It may not always look like it, but we do have seedlings under all those weeds.

Heat, humidity, wind, rain, and lightning are all expected hazards, but uninvited guests and freak storms are what keep us on our toes.

A black widow in the weeds at the base of one of our grass plants at SREC.

Damaged leaflets of a Tephrosia plant at SREC, most likely caused by a hail storm the previous evening.

We found teeth marks on this section of irrigation tubing at PDREC.