Wednesday, November 3, 2010

The Less-Visited Lost Pines

One of the features that I enjoy about central Texas is that, ecologically speaking, we are located on an edge.  Austin is built across the Balcones Escarpment, the fault line responsible for all our springs and a geologic line across which soil type changes.  More broadly, we are also located where east meets west on this continent, or where the humid forests of the east give way to fertile savannas and prairies and then to the arid mix of dry savanna and shrubby deserts to our west.  Here in the middle we have a little of everything - fields of wildflowers, shrub- and cactus-filled pastures, oak savannas, cedar woodlands, and, where the water flows, deciduous forests.

Not far to the east, we even have a pine forest.  Which is where Lee and I spent the day on Sunday - hiking in the piney woods of Buescher State Park.  I am now a fan of quiet and lesser-known Buescher, but I have to admit that we ended up there somewhat by accident.  We intended to hike at McKinney Roughs Nature Park, but twice now we have arrived at McKinney Roughs to find that the gate was closed.  The first time was on New Year's Day - we thought it would be a good day to hike - and the second time was last weekend, when we found out that the park does not open until noon on Sunday.  Noon?  For hiking in Texas?  Seriously?

Frustrated and annoyed, we consulted the guidebook and considered other hiking options along Highway 71.  Bastrop State Park was twelve miles down the road, but I had already hiked that trail and, though it was lovely, I was specifically craving a new place to hike.  Another ten miles down the road was Buescher State Park with its own hiking trail through piney woods, described in the guidebook as "an underhiked trail in an underutilized state park."  Now that sounded like my kind of place, and they opened before noon, so we headed farther east on Highway 71.

Buescher State Park, like its more-famous cousin to the west, Bastrop State Park, is located in the ecological region called the Post Oak Savanna, which is characterized by grasslands interspersed with clumps of hardy trees, mostly Post Oaks, that are adapted to drought and sandy soils.  In the Post Oak Savanna, forested areas are usually restricted to the bottomlands along rivers and streams, where flooding and clay soils support a diversity of deciduous trees and shrubs.

Yet Buescher State Park and Bastrop State Park are forested, supporting not just forest, but the westernmost stand of Loblolly Pine trees in the United States.  Separated from the Piney Woods of east Texas by 100 miles of savanna, the Bastrop County pine forests are called the Lost Pines.  The Lost Pines may be a remnant of a larger pine forest that once covered more of Texas in a wetter time, or may have been planted by Native Americans.  Either way, the Lost Pines have existed in the Bastrop area for over 18,000 years and require less water than their Piney Woods relatives, from whom they have become genetically distinct.

Loblolly Pines (Pinus taeda) prefer deep, sandy soils and, if provided with sufficient water, are fast-growing trees that can grow over 100 feet tall.  Loblolly Pines are extensively cultivated in the south for pulp and lumber.  Loblolly forests attract butterflies and provide nesting sites, cover, and seeds for birds and small mammals.

Loblolly Pine (Pinus taeda)

The Buescher Hiking Trail, which is a "balloon" hike, or an out-and-back with a loop at one end, is seven miles round-trip from the main trail head.  We shortened the hike to four miles by parking across from the entrance of the University of Texas Science Park, which is 1.7 miles up Park Road 1C, and picking up the trail where it crosses the road to the science park.  Complete instructions for getting there, where to park, and the hike itself can be found in the guidebook

The trail was sandy and covered in pine needles, which were also draped over the understory vegetation, giving the forest a decorated look.  As promised, the trail was quiet, and we saw only one other hiker as we walked through the woods.  The trail meandered through the pine forest, down into dry ravines and back up again, crossing park roads three times during the loop.  The forest varied along the trail, with dense understories in the ravines giving way to open woodlands on hilltops, but was composed, throughout, of a mix of Loblolly Pine, Blackjack Oak, and Post Oak.

Buescher Hiking Trail

Blackjack Oak (Quercus marilandica) is a red oak with distinct, triangular-shaped leaves with narrow bottoms and three-lobed tops.  Blackjack Oak is grows to be a small- to medium-sized tree and is able to grow in thin, sandy, dry, or rocky soils where few other woody plants can survive.  Blackjack Oak provides cover and nesting sites for birds, and its acorns are food for small mammals and deer.

Blackjack Oak (Quercus marilandica) leaves

Post Oak (Quercus stellata) is the most common oak tree in Texas and is so common in east Texas that it has an ecological region, the Post Oak Savanna, named after it.  Post Oak prefers acidic soils, but otherwise can tolerate a wide range of poor soil conditions, including dry, sandy, rocky, and gravelly.  Post Oaks are white oaks whose leaves have round lobes, but the exact dimensions of the lobes vary greatly.  The first or second set of lobes is often larger than the others, giving the leaf a cross-like appearance.  Post Oaks provides cover and nesting sites for birds, and its acorns are food to small mammals and deer.

Post Oak (Quercus stellata) leaves

Post Oak and Blackjack Oak are the primary trees of the Cross Timbers region of Texas and Oklahoma, the region north of us where the rainfall-determined "tree line" of the southern plains occurs.  In the Cross Timbers, where oak savannas give way to prairie, Post Oak and Blackjack Oak are the only trees that can tolerate the dry, poor soils away from the waterways.  As a result, both oaks have gotten the reputation of being ugly, slow-growing, small trees.  Though slow-growing, Post Oak and Blackjack Oak are also long-lived, providing shelter and food for wildlife, and timber and firewood for people, in a region where trees are scarce.  When Post Oak or Blackjack Oak trees have the opportunity to grow in deeper, more fertile soils, they can grow to be large, attractive trees, much like their more-loved oak relatives.

The dominant shrub in the understory along the trail was Yaupon Holly (Ilex vomitoria).  In sunnier spots, the shrubs were covered in red berries.  According to one source, the red berries of the Yaupon shrubs are poisonous, but another source said that they are food for mammals and birds, who only eat the berries after several freezes.  The evergreen leaves and twigs of the plant are high in caffeine, and can be steeped to produce a maté-like tea.  The dense shrubs provide good cover for birds and small animals and their spring flowers attract butterflies.

Yaupon Holly (Ilex vomitoria)

Sunday was a hot, sunny day, probably the hottest day for the rest of the year, and the forest seemed weary from the weeks of heat and dry of October.  I saw American Beautyberry shrubs in the understory, looking wilted and heat-stressed, with fewer, smaller berries than those I have seen on the plants along the Greenbelt.  Along the sandy section of the trail that paralleled the park road, I saw Small Palafox plants at the end of their bloom, as well as various, small sunflower-family herbs that were done or near to being done blooming for the year.  Dead pine trees were a common site along the way, standing bare among other trees or lying across the trail.  We had to make several detours over, under, or around dead pine trunks.  

I wondered, as I noticed the bare trunks along the way, what had caused so much tree death.  My first guess was that the drought of 2008-2009 was the culprit, given all of the other tree death that I have seen around Austin since those years.  But Loblolly Pines are also susceptible to southern pine beetle infestations and various fungal diseases.

I saw many juvenile pine trees along the way, a sign that the forest is regenerating.  Hopefully our pine forest, whether a relic from a different time or a gift from a different region, will continue to thrive in Bastrop county for another 20,000 years.

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