July 2017

We cannot succeed in restoring ecosystems unless we take care of ourselves and each other in the process.

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A Carolina Wolf Spider has made a home of a hollow, broken-off limb of Cedar Elm.  If I were as big as a bug (but not as smart), this might look like a nice hammock to loaf in.  It isn’t.

This site follows an array of ecological trajectories with an eye for intervention.  Ecosystems can move in slow or subtle ways, which can cause the illusion of a stable state.  Actually though, the land is always leaning.  Every part of the land is leaning.  Some parts lean in the same direction as others, or they can lean in opposing, or more often, cockeyed, directions.  For the most part, “balance” does not really come up.  Something can lean one way or another for a long time, and then just stand right back up, or lean the other way.  If we are watching, though, we can time it just right and push it over the edge.  Or on the verge of collapsing, we can swoop in and prop it up until it finds it’s feet again.

Take for example a grassland in Texas.  A relatively cool and stable climate in the late Holocene has allowed an increasingly ornate landscape to form.  Endemic species form in caves and on steep slopes and mild valleys.  Suddenly, species migration rates accelerate rapidly and the climate warms (both associated with mass release of fossil energy for human economy).  Several keystone animal species are lost (prairie chickens, buffalo) and many others are in sharp decline (migratory songbirds).  At this point, parts of the system lean towards closed canopy woodlands, other parts lean towards dominance by exotic grasses.  Both outcomes would make the system less resilient to the disturbances that are typical of the landscape, and would collapse a land that many declining species have come to rely on.  Woodlands or exotic grasslands both have ecological functions and provide ecological services to society.  Intervention, though, is to optimize the land for its own health and for the benefit of society.  Fluctuations in weather provide opportunities to hold up the parts that sustain the historic assembly or undermine the parts that lead to a loss of ecological integrity.  This site is about those parts, and the methods we use to interact with them.

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Side view of the above.

Every aspect of the ecosystem has an edge.  Maybe deer browse is limiting the food supply for migratory pollinators.  Where is that edge?  Can we push it?  Maximilian Sunflower and Plateau Goldeneye grow fine, but more palatable species, like Cutleaf Daisy are uncommon, and Purple Coneflower is absent.  Can we we manage the habitat to promote Cutleaf Daisy?  Introduce Purple Coneflower?  Beyond that, Compass Plant?

We can search for this edge, and cultivate our response to it, in every aspect of our lives.  It is the present moment.  It is an endless wellspring of energy that cannot be grasped.

What is happening now?

It is hot and dry of late, a good time for burning.  There was a short burn window in late June (we didn’t catch it), and now another one starting about two weeks after the last rain.  It wasn’t a big rain, a week or ten days may have been enough.

Live fuel moisture in Ashe Junipers is under 100%, which is good, they will readily combust with moderate fine fuels underneath if the wind and humidity are adequate to carry a flame front, but they are not dry enough for crown fire (tree to tree transmission).  Ashe Junipers are highly drought tolerant (anisohydric), meaning they keep their stomata open during drought.  They keep breathing (respiration) and making energy (photosynthesis) through the worst droughts, despite that they loose water in the process.  As a result, live fuel moisture in Ashe Junipers can be a rough proxy for drought condition on the whole ecosystem, including the part of the soil profile that is colonized by roots.  They keep pumping water no matter what, so if the land is dry, they are dry, and same if wet.  Another woody plant that grows in about the same places as Ashe Juniper is Plateau Live Oak.  Plateau Live Oak is isohyrdic, which means that it closes its stomata during drought.  As a result, the live fuel moisture content of live oak leaves does not fluctuate with drought condition.  It sort of holds its breath (to conserve water), and maintains a very low metabolic rate, a form of dormancy.  Plant dryness in Ashe Juniper fluctuates with drought status, whereas plant dryness is relatively constant in live oak.  Live oak mortality from fire is probably related to drought status, even though live oak plant dryness is not related to drought status, because drought stress on the plant (i.e. embolism, cavitation) makes it less resilient to additional stress from fire, just like it is less resilient to other stresses, like infection.  Or so it seems.  This may be true for several species, but Mountain Laurel?   Who knows…  A recent study found it is the least likely woody plant in Texas to die from drought.

The crop of Silver Bluestem seed is still standing but weakening, I suspect it produces seed in response to rain, so these past couple of weeks it has been just dropping seed but not replacing it.  Texas Cupgrass seed is all dropped, not a one yet at hand.  White tridens is ripe on shallow soils, but green on deeper clay.  Wedelia is at peak ripeness, and Golden Gray Aster is getting close, it looks like it will synch with most of the White Tridens.  Texas fescue still holds ripe seed.

The northward march of non-native invasive species continues…  As of this spring, single plants of Kleberg Bluestem are almost common in the natural areas Travis County, but I have found no actual stands (clusters of several plants).  Silky and KR bluestem are cured and have dropped their seed, but Kleberg is still green, which might indicate a longer treatment window.

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