Rangeland Analysis Platform

New data source for In-Season NDVI:  Rangeland Analysis Platform. (RAP) https://rangelands.app/rap/ 

RAP allows mapping of Cover and Biomass, and generates reports for an Area of Interest for Cover, Annual biomass, and 16-day biomass.  I'm hopeful they will upgrade the map to include 16-day biomass.  If they did, I could add it to the comparisons of the other NDVI sources.  Mapping would allow in-season management decisions based on forage production.

Case Example: Dugas, AZ

This series of years from 2018-2023 shows the variability in biomass production by season in a desert grassland at mid-elevation (4,000 ft) in AZ:

2018 shows a drought year, when there was little to no spring green-up due to a lack of winter precipitation, and a low green-up in response to summer monsoons.

2019 and 2020 were the "nonsoon" years, when the summer monsoons failed to materialize.  However, because the winter rains were good in 2019 and exceptional in 2020, total production was high.

2021 and 2022 show the potential for growth in years of good monsoon rains.  2023 shows a "normal" year with bimodal peaks in production corresponding to the spring green-up peaking in late March, and the summer monsoons peaking in mid-August.  However, for some reason this year had almost no annual biomass production associated with the monsoon.  Each year is different!

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Case Example: Congress, AZ

This series from around Congress, AZ shows the extreme variability of plant growth in the Sonoran desert (2,500 ft).

In drought years like 2018 and 2022, there is almost no plant growth, whereas the extreme winter precipitation year of 2020 annuals produced almost 130 pounds/acre of spring growth.  None of the years hadmuch perennial herbaceous production, and monsoons inconsistently produce up to 40 pound/acre of growth in good years.  

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Case Example:  Grand Canyon Junction 

SR-64 and SR 180 intersection, just south of Grand Canyon high-elevation grassland (6,000 ft).

Maximum production compared to the lower elevation sites is lower, only reaching 50 pounds/acre in good years.   However, total annual production is usually more consistent.  There is still the potential for bimodal production peaking in the late spring (early June) (2023 and 2017, not shown) and in the monsoons.  The monsoon peak seems to be most consistent, except in 2019 and 2020 when the monsoons failed - luckily those years had relatively good spring growth.   

In contrast to the low desert site, annual production (red) is usually less important than perennial production (green) at this site:

Spring Update: NDVI Differences

Last September, I wrote about Finding the Greenest Place in AZ.  This Spring, we have continued to compare and evaluate the different NDVI difference mapping applications and compare them to the actual growth of wildflowers and grasses we see when we go out hiking.  

Methods

I conduct pre-field research to identify predicted greenness/moisture from UA's Droughtview, USGS VegDRI, and NWS Accumulated Precipitation.  I take a screenshot of each product and assign the proposed site a scale from 1 (driest) to 10 (greenest).  We then visit the area and evaluate the plant production, recording example photos of overall landscape greenness, as well as assigning a score.  The data are organized in a OneNote table.  I then compare the numerical scores in an excel table, adding up the differences between each model and the observations.  

Results

So far, the UA model seems to slightly overestimate greenness, the USGS model greatly underestimates greenness, and the NWS precipitation record comes out closest to observation.

For the UA model, I think it might be helpful to have a difference from maximum, instead of the difference from period. The latter overestimates early spring greenness when the denominator NDVI is very small, so any amount of NDVI in the numerator saturates the index.  Using the maximum NDVI for that pixel could help with this phenology issue.  Plus, % of maximum NDVI may be more intuitive than “difference from average”.

The USGS VegDRI index consistently estimates pre-drought to severe drought in areas that have above average precipitation this water year and have an NDVI above average.  This leads me to think that VegDRI 7-Day eVIIRS is either not well calibrated to the desert southwest, or perhaps that it is better used as a predictive index – perhaps these areas are drying out even though they currently appear green?  However, SWCC does not show significant vegetation drying yet in the areas I assessed.  

Examples

Wingfield Mesa:  UA Droughtview shows this area at maximum NDVI (for this time of year)(=10/10), USGS showed it as pre-drought to moderate drought (4/10) , and NWS shows 125-200% of normal year to date precipitation (9/10).  It is quite green, but it is still early in the growing season and the mesquite have not leafed out yet.  We rated it 6 out of 10.  

Dugas Rd:  UA shows above average (8/10), while USGS showed Moderate drought (3.5/10) and NWS showed slightly below average precipitation (75-90%) (3.5/10).  It is quite green right now, but again not quite at maximum greenness production.  We rated it 8 out of 10.   

Post Exertional Malaise in Long Covid

 Severe exercise-induced myopathy has been found in long COVID post-exertional malaise (PEM).  

Just look at these long COVID patients (in red) pushing close to 20 mmol/L lactate on the exercise bike!  That is serious dedication for a group of patients who know what the consequences will be.

After the exercise test, blood metabolomics show elevated glycolysis, but decreased pyruvate and TCA cycle metabolites.

Muscle biopsy metabolomics show decreased purine synthesis and TCA cycle.

Key:

Appelman, B., Charlton, B.T., Goulding, R.P. et al. Muscle abnormalities worsen after post-exertional malaise in long COVID. Nat Commun 15, 17 (2024). https://doi.org/10.1038/s41467-023-44432-3

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).

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

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.

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.