Archive for the 'Botany' Category

Why and How Leaves Change Color in Fall

Tuesday, September 18th, 2018

Colorful fall foliage at Garner State Park.

This is Passport to Texas

Why is the sky blue? Why do birds sing? Why do leaves turn color in fall? We’ve got you covered on fall foliage. It begins with longer nights…

…which is a signal that winter is coming. And, a consequence of that is the leaf is no longer making chlorophyll and other pigments start to show up. Some are already there, some are produced after the leaf stops making chlorophyll.

Damon Waitt is director of the North Carolina Botanical Garden, formerly of the Ladybird Johnson Wildflower Center. Another part of the “coloring” process is when leaves seal themselves off from the trees.

And it’s during that time that the leaves are changing color. Because one of the coolest colors, of course, is red and purple. You know, the Big Tooth Maple colors. That’s actually a pigment called anthocyanin, and it’s produced when that leaf is cut off from the rest of the plant. And the sugars that are still left in that leaf will actually convert to this pigment and turn red.

A chemical process (triggered by longer nights) causes leaves to change color. However, other variables affect the depth of color.

So, there are a lot of things that can affect how deep the reds are: temperature, sunlight…all these things have an effect on the expression of these different colors. And, that’s why each fall is different.

Now, go forth and amaze your friends with your newfound knowledge.

For Texas Parks and Wildlife, I’m Cecilia Nasti.

Fall is Nearly Here and so is Fall Color

Monday, September 17th, 2018
Fall foliage and fishing at Garner State Park

Fall foliage and fishing at Garner State Park

This is Passport to Texas

Tis the season when we see foliage turn colors. If you’re like me, you wonder why, and what purpose it serves.

Right. It’s kind of like, why is the sky blue type question. But the interesting thing about fall color is it doesn’t really have a purpose. It’s the result of some chemical processes that occur in the leaf.

Damon Waitt is director of the North Carolina Botanical Garden, formerly of the Ladybird Johnson Wildflower Center.

When you think about being a leaf during the wintertime… it’s not a good time to be a leaf. Especially if you’re a thin flat one. Because, cold temperatures are going to kill that leaf.

So, these trees cut their losses as seasons change.

They want to capture all those good chemicals out of the leaf before winter and put them back in the tree and store them in the roots. And so that’s what they start to do when the nights get longer, which is a signal that winter is coming. A consequence of that is the leaf is no longer making chlorophyll; other pigments start to show up.

Damon Waitt likens this process to recycling.

Yes, trees are great recyclers. They don’t want to waste all those great chemical compounds that are out in the leaf that have been doing work all summer long, and in the spring, causing the plant to grow. So, they recycle the chemicals they can, and then dispose of the leftover material that’s in the leaf.

That leftover material is what you rake every fall. More fall foliage tomorrow.

For Texas Parks and Wildlife, I’m Cecilia Nasti.

City Nature Challenge Seeks Experts

Tuesday, March 13th, 2018
Upload images to iNaturalist during the City nature Challenge.

Upload images to iNaturalist during the City nature Challenge.

This is Passport to Texas

In about a month, competitors from around the globe will head outside with their smart phones to photograph the flora and fauna of their regions, and then upload those images to iNaturalist as part of…

The City Nature Challenge.

Marsha May is a biologist and challenge coordinator for the Austin region—one of seven TX regions involved.

And there are over 60 cities worldwide that are involved in this challenge.

April 27th—30th, participants worldwide will try to “out-document” their competitors, for bragging rights.

All that data is collected in iNaturalist, and it will be evaluated a week after the challenge is over.

Regions can win for most observations, verified species or members. May said last year’s event drew nearly more competitors than they had experts to verify the data.

We really needed more people to help with verifying the observations. That’s the call [to action] I would like to make. So, if you’re a herpetologist, a birder, a botanist and such—please, help us verify. Go to iNaturalis[.org] and look for the projects. You can go to any one of the cities and help verify these observations. Because, the more we get verified—that’s research grade observations—so those count more toward this contest.

The Wildlife Restoration program supports our series.

That’s our show… For Texas Parks and Wildlife…I’m
Cecilia Nasti.

Compete in the City Nature Challenge

Friday, February 23rd, 2018
Cities taking part in 2018 City Nature Challenge.

Cities taking part in 2018 City Nature Challenge.

This is Passport to Texas

Document local flora and fauna when you participant in the Worldwide 2018 City Nature Challenge, April 27-30.

Each city will have a leader; that leader will bring in partners [like the city, county or environmental organization]. And they will ask participants to do bioblitzes within that city. A bioblitz is where you collect data on all the plants and the animals throughout the area.

Marsha May is a biologist and Austin area challenge coordinator. Teams from six continents will upload their observations to iNaturalist.org in an attempt to document more species than their competitors.

Then all that data is collected in iNaturalist, and it will be evaluated a week after the challenge is over, and a winner will be announced.

Experts from various fields will verify the data. No prizes will be given to winners, but they will get bragging rights, and a chance to help researchers.

We have many species in Texas that are species of greatest conservation need. And when we do these biolblitzes, oftentimes those species are identified within that project. And those species are very important for us to know where they’re located, and how many there are out there. And this is just a way that citizens help quite a bit.

For more details on the 2018 City Nature Challenge, April 27—30th go to citynaturechallenge.org.

For Texas Parks and Wildlife…I’m Cecilia Nasti.

City Nature Challenge

Thursday, February 22nd, 2018
Photo: iNaturalist.org

Photo: iNaturalist.org

This is Passport to Texas

Game for some friendly competition? Then join teams from 60 cities, on six continents, to compete during the City Nature Challenge—April 27-30th. Teams will attempt to document more plant and animal species in their regions than competitors in other regions.

And we are using a format called iNaturalist, which is a real easy way of collecting data. All you have to do is take pictures of things. You don’t even have to know what it is.

Texas Parks and Wildlife biologist and Austin area challenge coordinator, Marsha May, says they need more experts to help verify data.

Professionals. People who know their plants. People who know their insects. Their invertebrates. Any of these organisms, to help us verify the data. You don’t have to live in any of the regions. Go to iNaturalist—especially those who use it regularly—because we need to get the data verified for it to count towards the contest.

Seven regions in Texas are hosting teams. Find them on the Nature Trackers page of the Texas Parks and Wildlife website.

It would be a good idea in advance, if people would check out iNaturalist.org. And join iNaturalist and see what it’s all about—practice it. And then when the time comes, they would just join the project as they’re collecting their data.

How the City Nature Challenge works… tomorrow.

That’s our show for today… Funding provided in part by Ram Trucks. Guts. Glory. Ram

For Texas Parks and Wildlife…I’m Cecilia Nasti.