September 2023 science summary

 Hello,

I had high hopes to do more reading this month but international travel and getting sick got in the way. So here are just two articles for some light summer reading.

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RANGELANDS AND SOIL C:
Provencher et al. 2023 models the potential carbon gains (and costs) to restore degraded rangelands (remotely sensed) in UT and NV (and some of OR, ID, and CA). The restoration sometimes involves herbicide to kill invasives and always involves: seeding w/ native perennial plants, excluding grazing for only 3 years from pixels that were seeded (grazing resumes after 3 years), and ending fire suppression. They found that invasive annual species like cheatgrass are more common than other analyses have found (Fig 8). See Table 3 for the key results: sequestration rates were very low in two sites (compared to less arid ecosystems) and modest in a third. Overall they ranged from 0.022 - 0.730 t CO2e / ha / yr (0.6-20 g C / m2 / yr). The best case scenario is in UT where ~$66 / ha delivers ~0.73 t CO2e/yr (+-50%), or ~$90 / t CO2e / yr (comparable to reforestation). Conversely the other ranches would be >$3,000 / t CO2e / yr. But selecting sites likely to be favorable to carbon accumulation could help make the case for ecological restoration (with empirical data needed if one wanted to sell carbon credits). And there is a LOT of degraded rangeland globally, so there's room to scale. To make carbon trading feasible in the Intermountain West, making this kind of seeding cheaper and more successful is important. 

INVASIVE SPECIES:
I couldn't resist reading Clark et al. 2023 right away despite my sad backlog. I once had a native plant garden guy tell me "at best non-native plants offer no value to pollinators and other wildlife, and most are harmful." Obviously false as an absolute! But how do they compare? Clark looked at 10 species in a Connecticut forest and found some invasive species (like honeysuckle) had more bugs (mass and protein) than the average for natives, but others (Japanese barberry) had fewer bugs. But birds seemed to forage both equally. It's a tiny study and I wish they hadn't pooled all native species, but I do like a study that counters "it depends!" to a truism in conservation.

REFERENCES:

Clark, R. E. (2023). Are native plants always better for wildlife than invasives ? Insights from a community-level bird- exclusion experiment.

Provencher, L., Byer, S., Frid, L., Senthivasan, S., Badik, K. J., & Szabo, K. (2023). Carbon Sequestration in Degraded Intermountain West Rangelands, United States. Rangeland Ecology & Management, 90, 22–34. https://doi.org/10.1016/j.rama.2023.05.004


Sincerely,
 
Jon
 
p.s. This is a photo of a fountain at a mini golf course in Wildwood, NJ