Friday, March 15, 2024

Lactic Acid in Health and Disease

 Introduction

Lactic acid is produced for energy when mitochondria can't use oxygen for aerobic respiration. 

Lactic acidosis develops when you have too much lactic acid in your body. Athletes monitor their blood lactate levels as a way to pace their training.  Chronic resting lactate levels greater than 2 mmol/L represent hyperlactatemia, whereas lactic acidosis is generally defined as a serum lactate concentration above 4 mmol/L.   High levels of lactic acid can cause muscle soreness, fibromyalgia-like symptoms, and anxiety.

Overproduction or Under-removal?

The body naturally produces and consumes lactate: although anaerobic exercise can raise blood lactate levels over 10 mmol/L, resting lactate in health adults is usually between 1 and 2 mmol/liter and is constantly produced and consumed.  High levels of lactic acid can be caused by overproduction or under-removal of lactate.


Resting lactate is usually between 0.5-1.5 in a large (10,000 participant) study of healthy adults.  More info.

Although many organs consume lactate, the liver and the kidney represent the major sites of lactate uptake and clearance as they metabolize approximately 53% and 30% of daily lactate production, respectively. Lactate is metabolized by two main mechanisms: First, lactate can be used as a substrate to regenerate glucose by gluconeogenesis, a process that is exclusive to liver and the kidney. Second, at least 50% of circulating lactate is removed and metabolized by means of oxidation during resting conditions. Unlike gluconeogenesis, which is restricted to liver and kidney, oxidation can take place in many organs, including the heart, brain, and skeletal muscle.

Supplements that affect Lactic Acid

Biotin (B7) is a cofactor required for gluconeogensis.  Aspirin can increase lactate levels by interfering with LDH lactate dehydrogenase, the enzyme responsible for turning lactate into pyruvate for gluconeogensis.   B1 deficiency impairs Citric Acid cycle and leads to accumulation of pyruvate and lactate.  Organic acids involved in the Citric Acid cycle may may provide substrates to better metabolize lactate and may reduce the acidifying side effects of elevated lactate (i.e. reduce Potential Renal Acid Load (NRAL)).  Nutrient deficiencies of CoQ10 and lipoic acid have also been associated with elevated lactic acid levels in both urine and blood.   Magnesium in muscles helps to decrease contractions and lactate buildup.  

Exercise

Slow exercise (i.e. HR below 100) can lower blood lactate and blood glucose levels in healthy adults.

Mitochondrial Dysfunction in Disease

Many diseases, included Type-2 diabetes, Chronic Fatigue Syndrome, and Long Covid, are associated with mitochondrial dysfunction and increased resting lactate levels.  Post-exertional malaise (PEM) is a major symptom of ME/CFS and Long Covid and may be caused by elevated lactate levels.  Although we don’t know the cure, #StopRestPace is the best treatment because only resting and then reducing/pacing activity can lower lactate levels.  

Lactic acid is being investigated as a possible metric of Long Covid and PEM severity.  If it plays a causal role in these diseases, methods that reduce lactic acid buildup may be promising treatments.  

Research

Elevated blood lactate in resting conditions correlate with post-exertional malaise severity in patients with Myalgic encephalomyelitis/Chronic fatigue syndrome. https://www.nature.com/articles/s41598-019-55473-4

-Patients having ≥1 lactate measurement ≥2 mmol/L defined elevated lactate group. The study included 123 patients. Elevated (n = 55; 44.7%) and normal (n = 68; 55.3%) lactate groups were comparable except for PEM, which was more severe in the elevated lactate group.


Decreased Fatty Acid Oxidation and Altered Lactate Production during Exercise in Patients with Post-acute COVID-19 Syndroms.  https://www.atsjournals.org/doi/full/10.1164/rccm.202108-1903LE

-The transition from fat oxidation to glucose oxidation occurs prematurely, suggesting metabolic reprogramming and dysfunctional mitochondria.

Figure 1 from paper.  Long Covid patients show greater increases in lactic acid at low intensity exercise compared to controls.  Blue and purple are Long Covid patients (with and without comorbidities (like diabetes), respectively) and grey and black are matched controls (with and without comorbidities, respectively).

Tuesday, February 06, 2024

A Health Supplement Dosed Incorrectly

A supplement with promising anti-aging results* is dosed too low by all supplement companies.  This review article by Life Extension (LE), contains lots of good information and citations about a fisetin.  

Source: https://www.lifeextension.com/magazine/2021/2/fisetin-senolytic-benefits

Fisetin is a promising senolytic that is found in low concentrations in strawberries.  It would be necessary to eat several pounds of strawberries to achieve an effective dose.  Life Exention (LE) is a reputable supplement company dedicated to anti-aging support.  However, even LE failed to select the right dose for their supplement.

The study cited in the review above showed effects in mice at 60 to 100mg/kg body weight per day (Yousefzadeh et al, 2018).  For humans, this would be more than 4 to 6 grams of Fisetin. Using a standard mouse to human conversion factor for effective dose, that would still be more than 325-550mg of Fisetin.  

Assuming the LE supplement is 25x as bioavailable (as claimed), it would still need to be dosed at 13-22mg (1 pill is only 8mg, so 2-3 pills/day). BUT: Yousefzadeh et al already dosed Fisetin in phospholipids (liposomes), so it is not clear that the LE supplement really is more bioavailable or if it would be the same. If it isn’t more available, a consumer would need to take 40 to 70 pills per day to match the dose in the mouse study. 

Although there are unknowns in translating animal doses to humans and determining bioavailability, in this case LE has human pharmacokinetics from the Akay study (Krishnakumar et al, 2022). That study used 192mg of Fisetin per dose, and measured peak plasma concentrations (Fig.5) around 250ng/mL. The LE supplement dose of 8mg is less than 5% of the tested dose, and is probably equivalent to the unformulated (ie insoluble) Fisetin in that study. 

So, in conclusion, LE developed a more bioavailable Fisetin. But they then dosed it to be as equally ineffective as non-bioavailable Fisetin.


References

Yousefzadeh MJ, Zhu Y, McGowan SJ, et al. Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine. 2018 Oct;36:18-28.

Krishnakumar IM, Jaja-Chimedza A, Joseph A, Balakrishnan A, Maliakel B, Swick A. Enhanced bioavailability and pharmacokinetics of a novel hybrid-hydrogel formulation of fisetin orally administered in healthy individuals: a randomised double-blinded comparative crossover study. J Nutr Sci. 2022 Sep 9;11:e74. doi: 10.1017/jns.2022.72. PMID: 36304817; PMCID: PMC9574875.   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9574875/


*However, recent results from mouse study did not find any benefit:  Harrison, D.E., Strong, R., Reifsnyder, P. et al. Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used. GeroScience (2023).  https://link.springer.com/article/10.1007/s11357-023-01011-0

Friday, January 05, 2024

Land Development Releases Greenhouse Gases

Land use change releases stored carbon and should be counted under Greenhouse Gas (GHG) reporting.  


Example of a wildflower meadow (left) that was bulldozed to create a parking lot (right). This land use change results in direct emissions of stored soil carbon and plant biomass, as well as continuing opportunity costs: the meadow can no longer accumulate sequestered carbon. If this land is owned by the developing company, this would count as Scope 1 Emissions under GHG reporting requirements.

New GHG reporting standards for land use change are due to be finalized in 2024. According to these new standards,

"Companies shall:

-Account for land use change emissions from land carbon stock decreases across all carbon pools (biomass, soil organic carbon and dead organic matter).

-Account for and report direct land use change (dLUC) emissions or statistical land use change (sLUC) emissions in scope 1, scope 2, and scope 3."

This is important because, according to the IPCC AR6 (2023), land use change accounts for approximately 15% of anthropogenic emissions.  Interestingly, the parts of the land and ocean that have not been developed by humans still absorb 30% of our emissions.  As we degrade more and more land and water, the Earth loses this buffering capacity, in addition to the extra emissions created from land use change.

Tuesday, January 02, 2024

UV Florescence

 iNat has a great project dedicated to UV florescence.  



Fluorescence generally means you’re absorbing one wavelength and emitting another. most UV flashlights emit light that is mostly invisible to humans, except for maybe a little that folks would describe as purple or pale blue.

So if you shine a UV light on something and see other colors emerge, you’ve almost certainly got fluorescence. but if you see the same purple or pale blue that your flashlight emits, then it’s possible that’s just reflection.

From left to right: visible light, UVIVF, and UV reflected light.  From: https://www.wildflower.org/magazine/native-plants/a-different-light


This article with beautiful UV and visible light photos helped me understand the difference between UV reflective and UV-induced fluorescence (UVIVF) images. However, I think many people, including the author of that article, are still confused about the biological meaning of UVIVF. For example, the False Gromwell writeup implies that insects can see UVIVF to help find flowers that are otherwise inconspicuous.

But UVIVF is never normally visible…except maybe as an added glow. The best example is laundry detergent that makes whites brighter. By adding a UVIVF chemical to the detergent, clothes actually slightly glow in any UV light, making them appear brighter.  

Meme by apermar.  Veritaseum explains more on Youtube.

Photographs of UVIVF in darkness show the extra brightness we see in sunlight, but usually don’t notice.  However, UVIVF may be biologically important to some animals, such as scorpions, frogs, and flying squirrels.  Taboada et al. (2017) documented biofluorescence in response to UV light can contribute between 18 and 29% of the total light emitted from some species of tree frogs under natural, dimly lit conditions.  

Flying squirrels fluorescence is hypothesized to aid in camouflage against a backdrop of lichens emitting similar fluorescent spectra, or potentially in Batesian mimicry of co-occurring predatory owls with similar biofluorescent profiles.

Biofluorescence could be a useful tool to document amphibians where the small, cryptically colored, and/or nocturnally active species can be hard to locate among leaf litter or dense vegetation. 

The study of UV florescence is relatively new, with new discoveries being made every year.  For example, 2017 was the first documentation (published paper) of an amphibian with natural fluorescence. A 2020 paper then found fluorescence widespread among amphibians.  iNat users had documented fluorescent amphibian from frogs starting in 2018 and salamanders in 2021.

A photo I took with a 390-405 nm (just barely UV) blacklight.  Most UV photographers use a 365nm (UV-A) flashlight, sometimes with extra filters to block all of the blue and violet light. 


More discussion of florescence can be found on the iNat forum.  

Taboada, Carlos; Brunetti, Andrés E.; Pedron, Federico N.; Neto, Fausto Carnevale; Estrin, Darío A.; Bari, Sara E.; Chemes, Lucía B.; Lopes, Norberto Peporine; Lagorio, María G.; Faivovich, Julián (2017-03-13). "Naturally occurring fluorescence in frogs". Proceedings of the National Academy of Sciences. 114 (14)

Lamb, J.Y.; M.P. Davis (2020). "Salamanders and other amphibians are aglow with biofluorescence". Scientific Reports. 10 (1): 2821.



Friday, December 22, 2023

Saving Biodiversity is Essential to Stop Global Warming

This simple message -that we can't save the Earth without saving the actual physical, water-and-soil-and-plant Earth- needs to be said and re-said until everyone understands.  

We've been disappointed by the scientists, leaders, and especially the "environmentalists" (like Sierra Club, Audubon, Union of Concerned Scientists, etc...) who have decided to advocate for industrial "renewable" energy as the only solution.  They've looked at the massive environmental destruction required to mine, manufacture, and construct solar and wind farms and connecting transmission lines - and said yes, we must destroy the world to save the world.

However, there is hope within the current system.  The push to save biodiversity, while sometimes sidelined, has significant support in the COP15 agreement.  That agreement, and related work by TNFD, will have to be considered, often for the very first time, by every company and gov't with sustainability disclosures.  

Even the IPCC addresses the importance of land use - the latest AR6* still shows global photosynthesis absorbing net carbon every year, despite human land-use change continuing to destroy that literal lifeblood of our planet.  

All numbers are gigatonnes of Carbon.  Image Source: Hillis, David.  Life: The Science of Biology.  Textbook published 2020 by Macmillan Higher Ed.  

According to the diagram above, net plant growth (photosynthesis - respiration) stores 3 gigatonnes/year of carbon, offsetting almost 1/3 of the yearly emissions from fossil fuels (9.5 gigatonnes/year).  However, human-altered land use and human-caused fires emit another 2 gigatonnes/year of carbon to the atmosphere.   A gigatonne is about twice the weight of all the humans in the world. (Source: https://energyeducation.ca/encyclopedia/Gigatonne)

Also, the upcoming (in 2024) standards for including land use change in Scope 1/2/3 emissions reporting will explicitly tie real environmental destruction (clearing forests, bulldozing farmland) to the statistics that accountants love to worship, total tons of carbon emitted.  Now developers (even of renewable energy) can't ignore the cost that continued industrialization has to the Earth's life-giving ability to absorb and store carbon.  

Source: https://ghgprotocol.org/land-sector-and-removals-guidance


Hopefully, with all of these connections being made, people will finally start to give credit where credit is due, and give thanks to our beautiful, fragile planet for all it does for us.


*IPCC overview diagrams of global carbon sinks and sources:

 AR6 (2023) : https://www.ipcc.ch/report/ar6/wg1/figures/chapter-5/figure-5-12/

AR5 (2013) overview: https://www.researchgate.net/figure/Simplified-schematic-of-the-global-carbon-cycle-IPCC-2013-Numbers-represent-carbon_fig4_281185559

AR4 (2007) overview: https://www.researchgate.net/figure/The-global-carbon-cycle-boxes-are-carbon-pools-and-the-arrows-the-fluxes-between-them_fig2_255642401

Sunday, November 05, 2023

Which State has the MOST ticks?

 Ticks spread a number of diseases, plus they are disgusting and annoying.  But which areas have the most?  Where do hikers need to take precautions?  Models have attempted to create "heat maps" showing when and where ticks are most abundant.  Another approach uses citizen science data:  where do people report seeing the most ticks?

I used iNaturalist data to compare relative abundance of ticks in several US states.  iNaturalist users post photos of observations on the website, which can be easily queried in the Explore tab.  However, some areas of the country have many more people using iNaturalist, so it is necessary to standardize the data by dividing by the total number of observations in each area.  This creates a metric of the relative abundance of tick observations compared to total observations.  

Another potential confounder is if some people specifically observe as many ticks as possible.  This could skew the results if one state had someone obsessed with tick photography, and another state didn't.  I corrected for this by subtracting observations from the #1 tick observer in each state.  Only one state (CA) had this problem.  This correction did not substantially change the results in CA, or any state.  

Data compiled from iNaturalist.org

The state/area with the most reports of ticks was California, but CA also had the greatest total number of observations of all life forms.  When corrected for relative abundance, CA is near the middle of the distribution.  Hartford, CT, famous for its tick abundance, topped the list.  Arizona and Washington had the lowest relative abundance.  Other top areas included MA, CT, ME, PA, and NY.

Monday, October 16, 2023

ESA-Listed Species in AZ: Status and Needs

Notes from Alexandra Permar's research into the current status and needs of ESA listed species in AZ.


Candidates Species for Listing

Monarch butterfly (Danaus plexippus): https://ecos.fws.gov/ecp/species/9743
 

Species with T/E Listing Status and Active Recovery Plans

Ute ladies'-tresses (Spiranthes diluvialis) (Threatened, G2): https://ecos.fws.gov/ecp/species/2159 | https://swbiodiversity.org/seinet/taxa/index.php?taxon=102217 | https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.129296/Spiranthes_diluvialis

Welsh's milkweed (Asclepias welshii) (Threatened): https://ecos.fws.gov/ecp/species/8400 |
https://swbiodiversity.org/seinet/taxa/index.php?taxon=3793#:~:text=Plant%3A%20perennial%20herb%3B%20stems%20erect,base%2C%20obtuse%20to%20mostly%20rounded%2D
Opportunity to survey for this species in northern AZ 
Recovery plan implementation progress is only about half done (maybe less than half).
Original delisting date (goal): 2010.
Needed: species surveys (in known and unknown locales in northern AZ) as well as communication campaigns to increase awareness and appreciation for the species.
Revised recovery documents (two five-year reviews) published in 2015 and 2021 indicate USFWS is collaborating with researchers at NAU and has hired private botanists to survey for this species in recent years. The botanists have conducted surveys and some research (e.g., controlled breeding in potted soils vs. native sandy soil type) which the USFWS is using. However, these two five-year plans (especially the 2015 one) reiterate the continuing need for many recovery activities including "… repetitive, standardized, rigorous surveys …."

Canelo Hills ladies'-tresses (Spiranthes delitescens) (Endangered): https://ecos.fws.gov/ecp/species/8098 | https://swbiodiversity.org/seinet/taxa/index.php?taxon=2715
Researchers with Desert Botanical Garden in Phoenix are researching this species (and using research dogs to find the plants--AZNPS Flagstaff chapter lecture on 09.19.2023)

San Francisco Peaks ragwort (Packera franciscana) (Threatened): https://ecos.fws.gov/ecp/species/1721 | https://swbiodiversity.org/seinet/taxa/index.php?taxon=567
USFS Rocky Mtn Research Sta. is researching the species (population, effects of climate change). They have research transects in the San Francisco peaks where they perturb and observe populations of P. fransciscana through time.

New Mexico meadow jumping mouse (Zapus hudsonius luteus) (Endangered): https://ecos.fws.gov/ecp/species/7965
There is ample work underway to protect this species (USFWS, NAU, AZGFD).
This species depends on mesic habitats in- and around wetlands which are rare in AZ.

Mexican spotted owl (Strix occidentalis lucida) (Threatened): https://ecos.fws.gov/ecp/species/B074
This species has been listed for a while and receives significant attention.

Sonoran tiger salamander (Ambystoma mavortium stebbinsi) (Endangered): https://ecos.fws.gov/ecp/species/D01H | https://ecos.fws.gov/ecp/species/2096 | https://awcs.azgfd.com/species/amphibians/ambystoma-mavortium-stebbinsi | https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.103735/Ambystoma_mavortium_stebbinsi
Need: Analyze data for AZGFD (population monitoring surveys conducted 2012-14) and USFWS (population monitoring protocol implemented 4x annually from 2004-13). It seems there has not been population monitoring conducted since 2014 in AZ. ??
Need: Conduct salamander surveys in Sonora, MX.
Recovery plan update conveys that USFWS et al. have reviewed the 10-year survey data and used it to understand the current status of the species. On the whole, the species is better off than I would've guessed; continuing concerns include bullfrogs, non-native predatory fish/crayfish, drought, reliance on cattle tanks for habitat, and climate change. Interestingly, periodic/episodic drought which dries some of the ponds/cattle tanks where the salamanders reside is actually good for the salamanders b/c predatory fish/crayfish/bullfrogs don't survive dry periods well. As a species, the salamanders depend on cattle tanks for habitat in AZ.

Chiricahua leopard frog (Rana chiricahuensis) (Threatened): https://ecos.fws.gov/ecp/species/D02F
This species has been listed for a while and receives significant attention.

Arizona Cliffrose (Purshia (=Cowania) subintegra) (Endangered): https://ecos.fws.gov/ecp/species/866
Botanists have already surveyed for this species and found all there is to find.

Masked bobwhite (quail) (Colinus virginianus ridgwayi) (Endangered): https://ecos.fws.gov/ecp/species/3484
This species is controlled through controlled active breeding programs and introductions at the Buenos Aires NWR; it seems most of the program isn't working that well. The controlled reproduction includes "foster parenting" of chicks. (When researchers introduce a masked-bobwhite-quail chick into BA NWR, they also introduce an adult male of another quail species with the chick; the male is supposed to foster the chick.) This species will probably go extinct.

Nichol's Turk's head cactus (Echinocactus horizonthalonius var. nicholii) (Endangered): https://ecos.fws.gov/ecp/species/5343
This species has already received ample attention; the recovery plan may resolve in this decade.

Bartram's stonecrop (Graptopetalum bartramii) (Threatened): https://ecos.fws.gov/ecp/species/8382 | https://swbiodiversity.org/seinet/taxa/index.php?taxon=3117&clid=3130
Difficult to survey for this species b/c it grows in "steep canyons" near water.

Jones Cycladenia (Cycladenia humilis var. jonesii) (Threatened): https://ecos.fws.gov/ecp/species/3336 | https://swbiodiversity.org/seinet/taxa/index.php?taxauthid=1&taxon=3703&clid=2670#:~:text=Plant%3A%20perennial%20herb%2C%201%2D,of%20follicles%205%2D10%20cm
This is a newly listed species (Aug 2021); it requires ample attention. Need habitat assessments and plant surveys, possibly also pollinator studies. However, most of this species' distribution is in Utah.

Kearney's blue-star (Amsonia kearneyana) (Endangered): https://ecos.fws.gov/ecp/species/7485 | https://swbiodiversity.org/seinet/taxa/index.php?taxon=1408#:~:text=Plant%3A%20perennial%20herb%3B%204%2D,broadest%20below%20the%20apex%2C%20slightly
Need census of species subsites; monitoring of species individuals and their habitat; education/outreach re: species conservation and recovery; surveys for new individuals and subsites.
This species used to be synonymous with A. palmeri which we found near Hillside, AZ in April, 2023 (https://www.inaturalist.org/observations/158329553).
Access to state- and tribal lands is restricted and inhibits botanical surveying efforts.
It is challenging to find the species in its native habitat; it grows in steep canyons and on cliffsides with slopes >= 20 degrees.
The survey sites for this species are paired with a nearby experimental site on BLM land where researchers are conducting controlled introductions of this species and observing their survival rates.

Pima pineapple cactus (Coryphantha scheeri var. robustispina) (Endangered): https://ecos.fws.gov/ecp/species/4919 | https://swbiodiversity.org/seinet/taxa/index.php?taxon=3428
This species has been listed for a while and probably receives enough attention.

Species with T/E listing but without active recovery plans

Yellow-billed Cuckoo (Coccyzus americanus) (Threatened): https://ecos.fws.gov/ecp/species/B06R
Many people are researching this species. However, survey data from the past 15-20 years for the Upper Verde region is missing from the Audubon Southwest AZ IBA Database. Need to coordinate with USFWS and Audubon SW to track down the data and analyze it. 
Need a 10(a)1(A) scientific research permit with the USFWS.
Description of Upper Verde River habitat (Yavapai County, AZ) is in USFWS Critical Habitat document (FR Vol. 86, No. 75, 04.21.2021) on pages 20855, 20881.
AZGFD management decisions (made for fish) in the Upper Verde watershed are--according to the USFWS--proving relatively sufficient to maintain suitable habitat for the YBCU. Thus, the USFWS has decided to not declare critical habitat for the cuckoo in the Upper Verde River watershed (AZGFD asked USFWS to not declare critical habitat here).
References cited in the USFWS Federal Register critical habitat document indicate that AZGFD, USFWS, and partners have analyzed recent data from the Upper Verde River watershed and find the cuckoo numbers (occupancy, breeding, migration) to be satisfactory. However, I searched for these original reference documents and was unable to find any of them.

Thursday, September 21, 2023

Finding the Greenest Place in Arizona

 I love plants, and I love places where plants are happy.  But how can I find the greenest places, especially when I live in Arizona?

In the Southwest deserts, plant phenology and growth are dependent on intermittent rains.  But the rains can be variable between nearby areas. 

Rainfall totals and percent of normal can be viewed using https://water.weather.gov/precip/ This uses observed (radar) precipitation. 

Displaying Last 90-Day Percent of Normal Precipitation from Sep. 20.


However, more important than total rainfall over the growing season is timing of rainfall.  A single deluge that brought 3 inches last week to an area that hasn't seen rain in 6 months, is not as effective in stimulating plant growth as regular weekly or biweekly 0.5 inch storms.

A better approach to locating areas of high plant growth is using NDVI (Normalized Difference Vegetation Index), or observed "greenness" from satellites.  Data updates every week or couple of weeks, depending on the satellite.

But some areas, like forests, will always look greener than other areas, like deserts.  What we really want to locate are areas of anomalous greenness.

This UA webpage calculates departures from last week, last year, and from the average year.

VIIRS NDVI difference from average from Sep 6.

Other resources include the USGS Vegetation Drought Model, VegDRI.  The Vegetation Drought Response Index (VegDRI) shows seasonal drought impacts on vegetation. The weekly index is produced using a model trained on the self-calibrated Palmer Drought Severity Index using MODIS satellite-derived greenness anomaly integrated with precipitation, land cover, soils, and other biophysical data sets. Updated every Monday by 10 AM. 

VIIRS NDVI as shown by the USGS VegDRI model.

Clicking on the map generates a time series, which can be useful to compare seasonal and yearly changes at a location.

Graph of VegDRI drought index for a location in Yavapai County over the last 4 years.


The United Nation's FAO also maintains an NDVI anomaly drought mapper that uses the European satellite AVHRR.  However, the data is only provided at the scale of entire nations.  

So where is the greenest place in Arizona?  As you may have noticed from the screenshots above, that depends on who you're asking!  I hope to "ground-truth" some of these models to learn which are most reliable for greenness-hunting.

Tuesday, September 05, 2023

How Advocates Stopped Aerial Insecticide Spray in NM

APHIS (a U.S. Government agency) routinely broadcasts insecticides across millions of acres of the Western U.S., in an attempt to control populations of grasshoppers.  Climate change (warmer winters, drier summers) has led to an increase of grasshoppers over the last decade, and APHIS has tried to keep pace.  https://acis.cals.arizona.edu/community-ipm/home-and-school-ipm-newsletters/ipm-newsletter-view/ipm-newsletters/2023/06/07/grasshoppers

Unfortunately, broad-scape application of pesticides harms numerous other animals (and people).  

A recent attempt to use airplanes to spray pesticides over the Rio Chama watershed in New Mexico was protested and eventually cancelled: https://www.xerces.org/blog/how-advocates-stopped-aerial-insecticide-spray-on-25000-acres-of-new-mexico-natural-areas

More Info:

Overview of Program:  https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/grasshopper-mormon-cricket/CT_Grasshopper_Mormon_Cricket

"Environmental Documents" opens a page with state-specific and site-specific Environmental Assessments.  This provides more info about areas in each state that have been treated.

In general, areas that show in red on aerial surveys will be treated in the following year. 

From:  https://www.aphis.usda.gov/plant_health/plant_pest_info/grasshopper/downloads/hazard.pdf

Annual grasshopper density surveys:  https://www.ars.usda.gov/plains-area/sidney-mt/northern-plains-agricultural-research-laboratory/pest-management-research/pmru-docs/grasshoppers-their-biology-identification-and-management/outbreak-and-survey-info/outbreak-and-survey-info/

APHIS has a large number of pest species with control programs: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/ea


Thursday, August 24, 2023

"Trying to define the undefinable": are taxonomists too focused on species?

A recent article in the New Yorker includes a good overview of why identifying species can be problematic:  

"You Name It: Carl Linnaeus and the effort to label all of life" by Kathryn Schulz, August 21, 2023 

Extended quote from article:

"What Linnaeus sought to do was organize nature according to its fundamental, intrinsic divisions--to carve it at the joints, in Plato's famous formulation.  But what he actually did, for the most part, was impose artificial categories on the natural world for the convenience of scientists.

This is not a retroactive assessment; Linnaeus himself knew full well the limitations of his classification method.  To achieve a system completely in accordance with nature was, he wrote, "the first and last wish of botanists."  But the more closely you looked at her bounty the more difficult that prospect became--so, in the meantime, "artificial systems are absolutely necessary."

In philosophy, this tension between intrinsic and imposed categories takes the form of a debate between nominalism and realism.  Realists believe that nature is full of real and discrete categories, from 'amphibian" to "zinc," and that the job of the scientist is to discern them accurately.  Nominalists believe that nature lacks clearly defined categories, and that we simply impose those distinctions upon it--creating, as it were, the illusion of joints where none really exist.  

This is not just the position of post-truth relativists.  "I look at the term 'species' as one arbitrarily given, for the sake of convenience, to a set of individuals closely resembling each other": that is Charles Darwin, in the second  chapter of "On the Origin of Species."  That book, of course, trumpeted to the world a very large problem with the entire notion of a species.  According to evolutionary theory, species are constantly changing--emerging, diverging, going extinct.

The very concept of a species is in radical flux, too, with more than twenty competing definitions in circulation.  Choosing a definition is not just a matter of what goes in the dictionary under "species"; which one you use will determine how you divide up nature, such that a group of creatures that would be regarded as a species by one standard might not merit the label by another.  

All this confusion comes, as Darwin wrote, "from trying to define the undefinable."  Yet committed realists continue to promulgate more and more definitions, in the belief that one of them will map perfectly onto some intrinsic and stable feature of nature.  Darwin called that idea "laughable," a word that captures the impossibility but not the gravity of arbitrarily imposing categories on living beings.