Wednesday, April 23, 2014

Living With Wildfire - Or Not.

Today our rural Pennsylvania landscapes are under a wildfire threat. Impressive winds and dry conditions. My time last week in Austin, Texas is definitely not the Mid-Atlantic, but a recent trip to the Capital of Live Music, did afford me a few short excursions to observe and compare how we live - or not - with increasing threat of wildfire.

The greatest challenge to ecosystems in the Hill Country region of Texas is the threat of wildfire, made more so due to severe drought conditions. Texas straddles the boundary between the East made wetter by warming oceans and more frequent and intense precipitation events, and the West made drier by less rain and hotter, longer dry seasons.

Blackjack Oak leaves are thick and waxy, an adaptation to prevent water loss.
Wildfire has become a daily threat almost year-round, especially for residents in the sprawling West Austin suburbs. Folks have pricey homes built inside or perched on the edges of the scenic canyons filled with highly combustible woodlands, composed mainly of the ashe juniper whose volatile oils literally explode the tree into flame. Many home owners were on the emotional edge in 2011 as the Bastrop County Complex Fire swept through the valleys below and burst up canyon walls like torches. "Every summer," a local confided, "I swear I worry 24/7 until a little rain falls. It seems a little rain is all we get anymore. Sometimes less."

Honey mesquite is a favorite for BBQ's and grilling because of it's fragrant oils.

The soils of Hill Country are naturally sandy and dry. Mesquite and oak predominated as the larger tree species found along streets and in parks. Some tree and shrub species have adapted to tens of thousands of years of fire cycles. Ladybird Lake, the main recreational and scenic feature of Austin provides waterfront habitat for many fruiting trees, willow, sumac, and ash, but also creates a worrisome path for canyon fires to follow in dry season. The famous Congress Avenue Bridge, occupied below by tens of thousands of Mexican free-tailed bats, has it's own observation park for bat-watchers who gather every evening to watch them take flight. It's a great view from the pedestrian walkway above, looking all around at this dry forest (where it isn't paved or built upon). The landscape is one of contrasts: bustling city and quiet waterfront, wetlands and uplands, wildland and a skyline that is rapidly transforming. The week of the Bastrop County Fire, more people gathered to watch the approaching flames and walls of smoke than bats.

People gather in the observation park to watch bats at the Congress Avenue bridge.

Being a Mid-Atlantic naturalist, the contrasts between our lush temperate forests, frequent rains, and abundant waterways and the Hill Country's dry sparse woodlands was stark: scarcity of water determines what, where,and how plants and animals survive here. Thorns and thick bark protects many trees and shrubs from browsing animals and sweeping fires. Animals that can dig, burrow, or roost in cooler places readily do so, while those left to the sun and dry conditions are scaled (lizards!) or plated (armadillos!). One of my mammal encounters was with a "herd" of huge eastern fox squirrels, clearly not as endangered as our own DelMarVa fox squirrel. Big, bushy, reddish gold, these Texas-sized tree squirrels did their best to recover every possible seed, acorn, or nut from the park near our conference hotel. A lone armadillo dug a burrow on a construction site I could watch every morning.

Austin's linear parks serve not only as wildlife habitat - valuable green space in an otherwise parched landscape, but also as wildfire corridors that potentially could bring fires directly into the city.

The threat of wildfire is a constant concern, though this is hidden from most tourists. Residents are asked to protect themselves and their property year-round. Yards are cleared of brush and flammable forest litter. Some neighborhoods that occupy canyons are at very high risk: when developers sited these tony communities in picturesque valleys, they ignored the drought-fire cycle history of the region and built directly into the combustible woodlands. Many canyon communities have only one way in and out, putting entire neighborhoods at risk. Not unique to Texas, the same 'prime' real estate development pattern can be observed in California and Arizona, where hundreds of ill-sited homes are lost in "one match fires" that become deadly infernos. 

2011 Bastrop Fire at Austin's doorstep. Credit: Austin Humane Society
I spoke to a Master Gardener who was leading a tour of Austin's beautiful pocket gardens. Lucy remembered well the Bastrop fire that destroyed 1700 suburban homes. Frightened family pets, not adapted to the fire-prone landscape - unable to burrow beneath or outrun the flames - fled through the outskirts of the city to protected parks and lake shores where they were gathered and housed nearby until owners could claim them. Displaced families, unable to take their pets with them to temporary housing sought foster families to care for beloved animals (including horses, llamas, donkeys, and goats) until new homes were found. "It makes you think very hard about where and how we live. Zoning laws need to take into account the natural and changing cycles of drought and wildfire seasons when permitting new homes," she said.

Credit: Bastrop Fire Authority, TX
Besides frightened and injured pets, the Bastrop Fire Authority noted that during the 2011 fire, numerous wild animals, including birds, bats, deer, and bear, fleeing the burning canyon hillsides fled into populated neighborhoods to escape the flames. A city on alert, Austin became a haven for wild and domestic critters alike. "It will happen again," said Lucy, "There is no doubt. We've built so far out into the canyons that we occupy wildlife escape routes. Usually they flee by following waterways and lake shores, but that is prime real estate these days. They flee through our yards and shelter in our gardens."

The fire alerts are up throughout Pennsylvania and I am thankful it is a fairly rare occurrence.  Even though fire is an essential ecological process, vital to many biotic communities, climate change and shifting land use forces us to reconsider how and where we live in relation to the possibility of a burn.

More about this complex fire - one of the most destructive in Texas history can be found here:

Austin Humane Society's film of the pet rescue:

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