August 2017

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It has been said that one hour of running will add seven hours to your life.   We are built to work hard.  We need to work hard to survive.  Running is good, and there are other ways to work hard.  We can run to benefit everyone.

July was an excellent month for prescribed burning on the Edwards Plateau.  There was a high potential to reduce woody plant cover.  High air and fuel temperatures, good fine fuel loading, moderate low humidity, moderate low wind speed, consistent wind direction, and low live fuel moisture in Ashe Juniper all prevailed.  Part of what makes current fine fuel conditions “good” is the continuity: the past few years have been wet enough for annual cool season grasses to punch into otherwise low fine fuel areas (rock/forby/dry sites), so even though it hasn’t been wet enough for grasses to get giant, there are more grass plants around due to several years of abundant seed and good conditions for germination and establishment.

This can also be a high-risk time to burn.  Hot temps exact a tax on staff and gadgetry, and lower combustion thresholds.  An integrative approach using fire physics and fire ecology found that fire models rely on overly simplistic tools to predict fire behavior, whereas any of a more comprehensive suite of physical factors can combine to determine ignition thresholds.  That article cites a model that uses fine fuel load to predict juniper mortality, and another (paywalled) by the same lead author (Twidwell) cites that managers rely on live fuel moisture for the same purpose.  Researchers have been pointing to a subtle confluence of factors that contribute to flammability and fire intensity for decades, but the practical reality is that fire managers can only effectively communicate a limited number of variables to working crews of fire fighters, who mostly already think they know everything, and need to be somewhat autonomous to function effectively.  So as with other restoration tasks, we must stay close to our innate and underlying humbleness, which is to stay open to the vast field of latent possibilities that might erupt from the familiar graveyard that stretches out before us.

Restoration is practice for dying.  Natural land and waterscapes, as comprised by their historic species assemblies, are failing all over the world.  Does that mean they don’t matter?  I hope not.  What is happening now is not separate from what came before or what is to come.  Restoration is a way of bracing ourselves, together with the land.

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Skeleton plant occurs sporadically as individuals or in small stands among mixed native grass, and produces new buds, ripe seed, and pollen-bearing flowers concurrently through the summer.

In restoration practice, we accept that we must do something that we don’t know how to do.  This is the conundrum we live with.  The system-response to our efforts is slow and ongoing and at least some aspects will be beyond our predictive capacity, and some even contrary to our aspirations.  Nature is the process of self-determination, and yet, we have influenced natural areas, and we go on influencing them.  We have to do something.  Nature is a fountain of unconditioned energy, moving through conditioned forms, such as ourselves.

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South of the Colorado River, live fuel moisture in Ashe Juniper has been exceptionally low.  In fact, they are as low as any time on record except for the devastating drought of 2011.  The early spring was dry, so the epikarst never had a chance to build a slug of near surface moisture before it got hot.  Early fall (2016) was hot, and the late winter (2017) was warm too (climate change), so evapotranspiration rates died down later and picked up earlier than normal surrounding winter.  Epikarst is the area below the soil but above the aquifer (water table) in karst areas (limestone with caves).  Compared to surface soils, epikarst is less exposed to direct evaporative demand, but is partially accessible by plant roots and also contributes to deep drainage aka aquifer recharge.  In the eastern Edwards Plateau, water has about a six month shelf-life in the epikarst.  Normal rains in part of the spring may have obscured the reality of plant dryness, which is in part determined by the six month average, and in this case, down-weighted by the outer limit of that legacy.

Our spring transect data show enormous increases in canopy cover since 2012.  As McPherson has pointed out, while extreme drought (2011) may seem like a boon that can slow or partially reverse the trajectory of woody plants encroaching grassland habitats, the net result is often the opposite.  Apparently, mass plant mortality can lead to rapid increases in woody plant encroachment when followed by a series of wet years (2013-2016).  Drought destabilizes the existing community, and then wet years strongly favor woodies.  Luckily, this rapid increase is mostly due to new plants, not canopy expansion from existing trees, and new plants are more susceptible to change than old.  So current dry woody plant/epikarst conditions may offer some relief to grassland habitats in this regard.

According to the forecast, August will be wetter than July.  If not, the fall seed crop will likely be quite lame.

 

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