The Biggest Problem in Conservation: Taxonomy

One of the interesting unspoken secrets of the conservation world is that taxonomists are in charge.  More specifically, what taxonomists consider interesting enough to name as a species or a subspecies determines what can be protected.  After all, it is the Endangered Species Act.  But what if the taxonomists can't agree on what a species is?

This excellent short article in the Atlantic provides examples form hawthorn trees, which, depending on who you talk to, are either in decline and in need of conservation, or so widely distributed and common that it would be like trying to preserve Kentucky Bluegrass.

"A few years ago, conservation groups were gearing up to assign the [balsam-mountain hawthorn] tree the rarest rank a species can receive, which would imply an urgent necessity to conserve it. But [a botanist] decided it was probably a hybrid of two other hawthorns. He still believed the tree should be protected, but instantly, the species went from critically rare to nonexistent, from a conservation point of view."

"A prominent evolutionary biologist, wrote in 1976,  that perhaps no true hawthorn species exist at all—that they make up a sort of genetic continuum that doesn’t allow for coherent species classification."

"[another] botanist... told me the biggest threat to the trees is not land-use changes but botanists themselves, who are unwilling to meet the taxonomic challenge. If no one takes on the task of categorizing hawthorns, then no conservation group can take any measures to save them."

"Now whatever solution [the botanists] come to will determine what we try to save."

Dendritic Stream Branching in the Piedmont and Triassic Basic

Who can spot Chapel Hill??

Prescribed Fire at Mason Farm

North Carolina Botanical Garden volunteer "Firebugs" conducted a controlled burn at Mason Farm last friday (March 15th) through the forest and two fields.  On Sunday an old log was still smoldering in the forest, while green grass leaves were already appearing from the charred field!

Bankfull Flood on the Haw River, North Carolina

There is abundant evidence of a bankfull flood event on the Haw River, upstream of Bynum, North Carolina.

Let's see what the USGS Gauge at Bynum says.

 A gauge height over 11 feet counts as a flood...and it is more than 7 feet above current flow.  Note that this is a very wide river, so the actual volume was much more than 7 times...according to the USGS calculation, the flow was near 20,000 CFS, over 30 times the current flow of 600 CFS.

How does the compare to previous floods?

This January flood appears to be a bankfull event that was surpassed in 2008 (the first year of record for Bynum), 2009, and 2010, (but not in 2011 or 2012).  Many of these large floods happen in the early spring, perhaps when the heavy rains fall on an already-saturated watershed.

This is what happened the week of January 13th.  On top of the previous week's rain, there was significant rain on Monday the 14th and Wednesday the 16th.  The storm continued into Thursday, bringing more than an inch of thunderstorm rain (and snow) on top of the saturated landscape.  The Haw river flow peaked soon thereafter, in the early morning hours of January 18th.

A Tree Dies in the Forest...

Eastern forest disturbance is primarily through canopy gaps.  These forests are ...."characterized by a long recurrence interval of disturbance relative to successional recovery time as well as small disturbance area."
HR Delcourt and PA Delcourt. Eastern Deciduous Forests. in  MG Barbour and WD Billings; North American Terrestrial Vegetation. 2nd Edition.

The Future of Forests...is People

 David Wear, USFS, predicts large declines in forest area in the US as more and more land is developed for housing.  Over the next 50 years the US population is forecast to double again to 500 million, mostly along the coasts. 
 

Most of the RPA interval projections by the USFS are driven by economic analyses.  Increased wealth greatly increases the impact of any increase in human population, because wealthier people build bigger houses, shop more, and need more roads.  More people will need more food, leading to higher food prices that threaten to undo the conservation reserve program, putting reforested land back into food production.  But higher prices for timber or biomass would actually increase forested area!  With a higher value on trees, timbered lands might be worth too much to develop....

I conclude that the US needs a healthy forest products (including, somehow, forest biomass) industry to push back against the teeming urban hordes.

Finally, after months of waiting, Thursday, April 12 was burn day at Mason Farm Biological Reserve.

It has been very dry here and Tuesday was a Red Flag day, but Thursday dawned cool and not-too-windy.

A little bit more wind would have been helpful to oxygenate the burn more.  Trees have already leafed out, decreasing below-canopy advective and convective air movement.

There were no problems with the fire lines, and the burn was finished by 5 PM.

For more information about natural fire regime in Southeastern Piedmont forests:

Frost CC, Walker J, Peet RK. Fire-dependent savannas and prairies of the Southeast: original extent, preservation status, and management problems. Wilderness and natural areas in the eastern United States: a management challenge. Nacogdoches, TX: Stephen F. Austin State University, School of Forestry, Center for Applied Studies. 1986:348–357.

Are Invasive Species Evil?

Mark Davis argues against seeing invasive species as evil aliens.

In his talk today, "Invasion Biology, the Science and the Ideology" Davis lambasted a prominent paper on Garlic Mustard invasion, Ready or Not, Garlic Mustard Is Moving In: Alliaria petiolata as a Member of Eastern North American Forests. 2008. Vikki L. Rodgers, Kristina A. Stinson, Adrien C. Finzi. Bioscience. He looked up a half dozen of their key citations and showed how the original papers did not support or even directly contradicted, the claims in this prominent paper. Davis argues, persuasively, that ecologists have been too quick to lay blame on invasive plants.

He wrote a paper in 2011, Don't judge species on their origins. 2011 Nature. Mark A. Davis, et al. arguing conservationists should assess organisms on environmental impact rather than on whether they are natives. Are invasive species drivers, or passengers of species loss. They may be beneficiaries rather than agents of change. Eventually, intraspecific competition triumphs over interspecific competition as invasive species run up against resource limitations. Over time, invasive species advantages may erode as other species learn to use them as resources, too. Negative soil feedbacks accumulate over time for non-native plant species. Ecology Letters. Jeffrey M. Diez, Ian Dickie, et al.

Wavelet Coherence Analysis!

I've started using a cool Matlab program that generates a 4-dimensional power spectra for any time series. A normal power spectra is averaged over an entire dataset, but this technique, called Wavelet Coherence Analysis using a sliding "window" to examine power spectra continuously over the entire series. Of course, for longer and longer wavelengths, the sliding window necessarily becomes larger and larger, until wavelengths can no longer be measured on the data. The dark black hemicurve on this diagram shows that limit, and the data greyed out beyond that line is edge-affected power spectra.

The data I chose for this analysis were the maximum daily temperatures for Chapel Hill, North Carolina, in 2010. There are 365 days along the X axis, and various wavelengths ranging from 4 to 64 days along the Y axis. Colors indicate "power" at a given wavelength, for a given time of the year. Significant areas within the hemicurve are circled with a black line.

This analysis shows that there were some 6-day cycles in springtime (near DOY 150) that were statistically significant. Beyond that, not much jumps out: the signal does now have high periodicity. Now I'm looking for better-behaving data.