The Drought Continues

We recently broke the record for number of consecutive days with high temperatures above 100 degrees. We're currently at 73 days but the forecasts say it may break in four days. We've had no rainfall at our house since June 22 and I'm worried about the impact on the plants and wildlife.

The grass has been brown for several months now and that's not really unusual, but the trees are starting to show signs of stress. Their leaves are turning brown and dropping. Trees lose quite a bit of moisture through their leaves through the process of transpiration. A fully-grown tree may lose several hundred gallons of water in a day. The trees minimize this loss by dropping their leaves and entering a dormant state.

I've noticed that the smaller trees are the ones turning brown, so they may be more susceptible to the water loss and stress.

There is no way for us to water all the trees so they're going to have to make it on their own. On the other hand, they've been out here for hundreds of years and have seen worse drought conditions, so they'll probably be fine.

Here's a photo of a grove of live oaks. The taller ones are still green but the small ones in front are not.

 Here's another one showing the same effect.

This is a photograph along our driveway in which the trees don't show much signs of stress. I think much depends on the soil and the general health of the trees.

The grass and trees are very visible signs of the heat and drought. They remind me though that many of the effects are not so easily seen. The wildlife especially has to cope with the lack of water too. The deer especially seem thin right now. I hope they make it.

Edible and Useful Plants

I was given a wonderful book as a gift a few months ago by my son and daughter-in-law. They hear me talking about my Master Naturalist adventures and also follow the blog, so they knew this one would interest me.

The book is "Edible and Useful Plants of  Texas and the Southwest" by Delena Tull. Ms. Tull is an environmental science educator and naturalist who lived in central Texas for twenty years and earned her Ph.D. in science education form the University of Texas in Austin.

The book was originally published in 1987 and was updated in 1999. It's in paperback, with about 500 pages, and has many plant illustrations and photographs.

She divides the book into seven sections:

1. Edible and useful wild plants
2. Teas and spices
3. Edible and poisonous berries and other fleshy fruits
4. Poisonous and harmful plants
5. Colorful dyes with Texas plants
6. Fibers from Texas plants
7. Rubber, Wax, Oil, and Soap: Industrial resources from Texas plants

In a brief introduction she discusses the vegetation regions in the state, the problems of using plants as medicine, and the dangers of trying mushrooms. The main problems with plants as medicine is the variability of the effect from plant to plant because of varying growing conditions and life history of the plant. You're never sure of the dose.

In each section she includes many warning about the dangers inherent in sampling native plants: poisoning, allergic reactions, etc. Nonetheless, there are many plants and fruits are quite safe to eat - the challenge is in making sure you've identified them correctly. She includes the history of usage, going back to Native Americans, and many recipes. There is much useful knowledge and folklore which we've lost in modern times.

I never considered the possibility of using dyes from native plants, although I knew the wood of agaritas (Mahonia trifoliolata) is a bright yellow on the inside and that the cochineal (Dactylopius coccus) insect found on prickly pears (Opuntia sp.) is bright red when crushed. I found that section quite educational and she has many procedures listed for creating dyes.

The other interesting part was in the last section of industrial resources from Texas plants. Did you know there are at least two plants in Texas which are a source  of rubber? They became important during both World Wars, when imported rubber was scarce, but commercial interest has since died off.

I doubt I'll ever be able to "live off the land", although that concept fascinates me. This book will help me find snacks, though, as I hike up and down the Hill Country.

7th Annual Naturescapes Awards Reception

We're holding the 7th Annual Naturescapes Awards Reception on Saturday, September 10th, at the San Marcos Activity Center, from 5:00 pm to 7:30 pm.

The reception opens the exhibition which runs from September 10th through November 4th in the Walkers' Gallery at the Activity Center. This is the first chance you'll have to view the beautiful  photographs showcasing the natural beauty in Hays County. There will be snacks, music, and social time before the awards ceremony.

In addition to the Best in Show prize and the Awards of Excellence we've had before, this year we will award a prize to the best photograph entered by a youth photographer and a prize to the best photograph which shows a natural  habitat. The Best Youth Photograph prize is sponsored by the Hill Country Photography Club and the Best Natural Habitat Photograph is sponsored by the Hays County Master Naturalists.

We had a record number of photographers and images enter and the contest was very competitive, which is great because it leads to a high quality exhibition. I'm especially excited by the number of young photographers who entered and were chosen for the exhibition. I'll have details at the reception.

It's a great chance to support our goals of promoting public awareness of the importance of protecting our natural  areas and recognizing photographers for their beautiful and inspiring images.

Tell your friends and family! I hope to see you there!

Flint Ridge Cave

Last year I got to work on a Hays County Master Naturalist project at a special place in South Austin, Flint Ridge Cave.

Flint Ridge Cave is one of the largest known cave systems in Travis County. It is also one of the most important recharge features in the county. It drains a 70 acre internal drainage basin which means that the cave entrance is the bottom of a 70 acre bowl. This is different than the typical watershed where small streams flow into rivers which eventually dump into the ocean. This watershed drains only to Flint Ridge cave which goes directly into the Edwards Aquifer. Annually, Flint Ridge cave alone contributes about 57 million gallons of water to the aquifer.

The cave entrance.

Leading our project was Matt McCaw from the Austin Water Utility, and Hays County Master Naturalist Tom Watson. The volunteers were Terry Tull, Cindy Luongo, Ruben Garza, and me. Flint Ridge is on a portion of the Water Quality Protection Lands in South Austin. The project involved planting grass seed in the area immediately surrounding the entrance to Flint Ridge Cave to stabilize and stop erosion and optimize the capture of sediments before they enter the cave itself. The grass seed consisted of several shade-loving species such as Canada Wildrye (Elymus canadensis) and Purple Top (Tridens flavus) and included the Broadleaf Woodoats (Chasmanthium latifolium) that had previously been colleted by Hays County Master Naturalists.

The city has installed three water flow monitoring chutes around the cave entrance. They measure and record the water flow as well as quality that flows into the cave.

A water flow monitoring chute.

The first step in the seeding project was to clear the leaves and debris to expose the soil.

After raking the leaves to expose the soil.

We then broadcast the seed by hand. The main goal is to make sure the seed has good soil contact and is evenly distributed.

Spreading the grass seed. Left to right: Terry Tull, Cindy Luongo.

Since the point of the project was to minimize the amount of erosion and sediments that enter the cave, we couldn't leave the soil uncovered. The next rain (this was last year when we still  got rain!) would wash our seed and some of the soil into the cave. We prevented this by spreading an erosion control mat - basically hay in a biodegradable netting. The mat protects the seeds and sprouts until they're big enough to take hold and eventually decomposes.

Preparing the erosion control mat. Left to right: Terry Tull, Matt McCaw, Cindy Luongo.

We then used landscaping stakes to hold the mat along the edges and also weighted the area with stones.

Almost done. The mat is staked down and weighted with stones. Lef to right: Cindy Luongo, Matt McCaw, Tom Watson.

As a special treat, at the end of the project, Matt McCaw, Ruben Garza, and I entered the cave and were able to explore for a short distance. I'll cover that in a future post.

Silly Rabbit

I took this photograph of a small cottontail rabbit earlier this year. It's actually an Eastern Cottontail (Sylvilagus floridanus), one of the most common rabbit species in North America.

We have ideal habitat for them and we see them frequently. They like open, grassy areas with shrubs along the edges for cover. This one was near our house, inside the fence and that is normally deadly territory for them, but our dogs were inside at the time.

They have a two-stage defensive strategy. First, they will freeze, which is what this one has done. Then if you approach closer, they will run away in a zig-zag pattern. They are quite fast and you never get really close.

They are mostly vegetarian although they sometimes eat insects. In turn, they are predated by coyotes, racoons, hawks, and owls.

There is another species of rabbit which we see on our property too, the black-tailed jackrabbit. They are larger, have longer ears with a black trim and have a long rear legs.

Texas Persimmon

I went on a short hike this afternoon even though it is quite hot. The current temperature is 101. It's not bad if you're in the shade, but the sun is a killer.

I've been indoors all weekend, working on the Naturescapes contest and the Hays County Master Naturalist newsletter, so I just had to get out.

I've noticed the Texas Persimmons (Diospyros texana) have put out fruit and wondered if they were ripening yet. The mustang grapes are. I'm surprised that these plants produce any fruit at all, given the drought, but there must be enough water for them to do it. The persimmons are shrubs or small trees, usually multi-trunked, about 5 to 15 feet tall. I noticed today that when they grow in the understory of trees they can get quite tall, probably because they're reaching for the light. When they're out in the open, they are more compact.

Here's a typical one, in the shade of some live oaks. It's about 10 feet tall.

They have beautiful, peeling gray - white bark.

The fruit are small berries, about 3/4 inches in diameter. They're green at first, but turn a deep blue, almost black, when ripe. I've eaten them before and they're quite good - very sweet. They are a favorite of birds and mammals. The juice leaves a stain on your fingers and lips for a while.

It's nice to know that even in the middle of this deep drought, the plants keep producing fruit, propagating into the future.

Prickly Pears

The Prickly Pear cactus (Opuntia) fruits are ripening right now. The fruits are edible and you can find many recipes for preparing them. They can be eaten raw and also made into jelliies and drinks. The pads are also edible and can be purchased at local grocery stores as nopales.

The prickly pear are also known as nopales or paddle cactus and there are 200 species in the genus, distributed throughout most of the Americas. They are native to the New World but have been distributed throughout the world.

We have many on our property, although I would not say they are so widespread as to be a problem. They are indicators of land which has been over-grazed, becoming more frequent as grass is grazed away, so they may be a sign of damage done to our land before we bought it. Although there are cattle grazing on our land, they are very few and not confined to only our property, and are definitely not over-grazing at this point.

We've taken a few out, by digging them out, but you have to be careful to remove all the plant material. If a pad lays on bare soil, it will root and a new plant will grow. They grow in clumps, usually only a foot tall and a foot in diameter, but some are larger: three feet tall and three or four feet in diameter.

I'm not sure exactly what species we have. The Wildflower Center lists two for our area and we probably have both: the Plains Prickly Pear (Opuntia polyacantha) and the Tulip Prickly Pear (Opuntia phaecantha).

They have beautiful, large blooms, which are about 3 inches in diameter and usually yellow. The cactus bloom right after a good rainfall. In this photo you can see a fully-opened flower and two others which are not yet open.

Some of the cactus have red in the flowers as you can see in this photo. You can also see the green, unripened fruit just below the spent flowers on the left.

Here's a photo of a large plant with many fruits. The photo was taken today, just outside of the fence around our house. The fruit turn a deep red, almost purple color, when ripe.

Finally, this photo, taken at the San Marcos Nature Center, was in the Naturescapes Exhibition in 2009. I like the clean, smooth curves of the pads and the texture provided by the short, almost knobby needle clusters.