Bees in the woods: Using solarization to control invasive species (in English)

(gentle music)

- After any type of disturbance

such as a management activity

like thinning or prescribed fire,

one concern is invasion
of invasive species,

and especially invasive annual grasses.

Invasive species can
outcompete native vegetation

and especially plants that
are important for pollinators.

Controlling invasive species
may need to be incorporated

into your management plan

not only after a management activity,

but throughout the life of the stand.

- Here at the High Desert Museum,

the number one invasive species,

we're dealing with each
year is cheatgrass.

So, behind us is one method we're using

to try to reduce the amount of cheatgrass

we have on the property and
that's called solarization.

And solarization simply put,

is taking thick plastic,
putting it on the ground

for an extended period of time

and cooking the ground to the degree

that you sterilize the soil

and everything living in the soil,

including cheatgrass, cheatgrass seeds,

and also even native species will die

over the course of that solarization.

We put this plastic down in April

and we'll leave it on the ground

through the spring into the summer

and then we won't pull it
back up again until the fall,

likely September.

And the reason we want it on the ground

for that interim of time is
so the heat through the summer

is able to really cook the ground.

Now, once we pull the
plastic back up in the fall,

we'll immediately begin to
replant and re-seed the site

with native species, including
bunch grasses and shrubs.

One of the reasons that we want to re-seed

and replant in the fall

is so we can use the natural precipitation

that this region begins to get

in the fall to the winter season

to help us establish those plants.

We might also need to irrigate

depending on what kind
of fall we end up having

when it comes to snow or rain.

So, solarization is actually
an experimental method

for us at the High Desert Museum.

We've never done it before.

If it does go well,

we will be able to reuse the
plastic you see behind us

on other sites that the museum owns

that might be dealing with cheatgrass.

- In addition to solarization,

treating invasive species

can be achieved with other techniques

such as herbicide application,

mechanical removal, or
even prescribed fire

or some combination of each of those.

- So we did use a
combination of those methods

before we would put down the plastic.

This plastic does require some upkeep

so sometimes you might need to come out

and retape portions of it.

And also, we end up having
to hand pull cheatgrass

that begins to escape and grow

around the very edges of the plastic.

Removing invasive species like cheatgrass

is critical to then support
healthy pollinator habitat.

This is just one of the
many methods we could use

to control invasives

and improve pollinator
habitat on our property.