We have been seeing spittle bubbling out of trees, especially in today's rain. Might be a spittlebug.
"a fat little dark-eyed green creature about the size of a sesame seed
called a froghopper nymph, so named for the adult insect's squat shape,
pop eyes and leaping ability. The nymph stage is better known as a
spittlebug. Froghoppers/spittlebugs insert their "beak" & suck
sap through their bodies, extracting nutrients. As the liquid comes out
the other end, mixed with soapy abdominal secretions, the insect puffs
air into it through a special organ, blowing bubbles. The froth flows
down and around the nymph (they feed facing head down), keeping it cool,
moist and hidden from you (unless you look)."
Tuesday, February 26, 2013
Saturday, February 16, 2013
Wednesday, February 06, 2013
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.
Monday, February 04, 2013
Sunday, February 03, 2013
February Blocking Pattern
This computer model (GFS) of near-surface temperature (actually, just above the boundary layer) and atmospheric pressure shows an interesting pattern of high and low pressure areas. A high pressure region over the Azores is predicted to hold steady for the next several weeks, in effect blocking the normal flow of the jet stream and Eastward-migrating low pressure regions. These lows are forced to travel (clockwise) all the way around the high pressure region. The consequence appears to be a trough in the jet stream over Eastern North America, leading to large incursions of Arctic air, and very, very cold temperatures (see graph).
Friday, February 01, 2013
Do endemic taxa correlate?
One of the main assumptions of many biodiversity assessments and conservation efforts is that biodiversity correlates across taxa. In other words, an ecosystem with high plant diversity might be expected to also harbor high lichen diversity, high arthropod diversity, and a great many birds, bees, and bloomin' confusion.
If this assumption is true, than scientists could study one taxa, say lichen, and use the results as a surrogate for studying all of the other possible taxa. But a new study by Dr. Che-Castaldo questions this "surrogacy" assumption:
Similar conclusions have been reached by a other studies. For example, Erhlich et. al. 2002 found that in subalpine meadows in Colorado, indicator taxa show no skill in predicting diversity of other taxa, even among phylogenetically related species (in this case, butterflies and moths).
If this assumption is true, than scientists could study one taxa, say lichen, and use the results as a surrogate for studying all of the other possible taxa. But a new study by Dr. Che-Castaldo questions this "surrogacy" assumption:
"Testing Surrogacy Assumptions: Can Threatened and Endangered Plants Be Grouped by Biological Similarity and Abundances?" Abstract: "There is renewed interest in implementing surrogate species approaches in conservation planning due to the large number of species in need of management but limited resources and data. One type of surrogate approach involves selection of one or a few species to represent a larger group of species requiring similar management actions, so that protection and persistence of the selected species would result in conservation of the group of species. However, among the criticisms of surrogate approaches is the need to test underlying assumptions, which remain rarely examined. In this study, we tested one of the fundamental assumptions underlying use of surrogate species in recovery planning: that there exist groups of threatened and endangered species that are sufficiently similar to warrant similar management or recovery criteria. Using a comprehensive database of all plant species listed under the U.S. Endangered Species Act and tree-based random forest analysis, we found no evidence of species groups based on a set of distributional and biological traits or by abundances and patterns of decline. Our results suggested that application of surrogate approaches for endangered species recovery would be unjustified. Thus, conservation planning focused on individual species and their patterns of decline will likely be required to recover listed species."
Similar conclusions have been reached by a other studies. For example, Erhlich et. al. 2002 found that in subalpine meadows in Colorado, indicator taxa show no skill in predicting diversity of other taxa, even among phylogenetically related species (in this case, butterflies and moths).
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