John Wendt

New paper! Molecules in lake sediments provide new information about past herbivores in Yellowstone Molecular signatures of dung vary among wild herbivores. Fecal steroids in lake mud show that bison/elk were dominant herbivores for over 2k yr in a small catchment. link 👇

@RealCalebKitson @RizomaSchool @Empty_America This is really insightful. There are many types of rotational systems. Some work better than others depending on the setting and objectives. Regarding trees, many open ecosystems don’t have any and even adding few can dramatically change habitat (certain birds go away).

Biodiversity is best supported by seasonal pastures, ie nomadism. Trying to produce it on a farm is incredibly intensive and requires constant management. Shifting to selective diversity ie rotational grazing thru a silvopasture/savannah type system is the most sustainable long-term with decreasing inputs from the farmer and minimizing seasonally-rewuired management such as coppicing, and grazing/browsing different species on different pasture at different times. But the up-front cost is highly labor-intensive, while monoculturism is mostly capital-intensive, which is how most economies are currently designed, and therefore incentivizes short-sightedness.

Video of feeding cows, with discussion of stocking rates, the grass cycle, etc. About 15 cows per 640 acres for year round grazing without too much need for feed.

@PubPlanPosting @RealCalebKitson @RizomaSchool @Empty_America Most but not all!

@johnafwendt @RealCalebKitson @RizomaSchool @Empty_America It’s carbon dioxide.

@RealCalebKitson @RizomaSchool @Empty_America Sorry no farm but I can send you some papers about really old poop

@johnafwendt @RizomaSchool @Empty_America I hope this guy actually has his own farm and is proving his theories like Peter Allen is.

@RizomaSchool @Empty_America @DoomerOptimism @pclarkallen sounds fun

@RizomaSchool @Empty_America Intermediate disturbance seems more a human preference than a description of historical disturbance patterns. Extreme events and non-events matter for system trajectory and biodiversity. Some species only occur at the extremes but humans often engineer cozy open woodlands.

@RizomaSchool @Empty_America yeah and carbon from fire tends to be more persistent in soil than leaf litter. I generally agree but not completely. Since the extinctions, fire mattered more than herbivores for keeping many “potential forests” open.

@PubPlanPosting @RizomaSchool @Empty_America Where grazing is intense I would expect less soil carbon but I’m not sure if that impact of wild horses has been tested

@johnafwendt @RizomaSchool @Empty_America Would you say the impact of feral wild horses on these lands would negate any headway?

@RizomaSchool @Empty_America We’ve learned a lot about mechanisms and effects. Restoring herbivores has benefits, especially where herbivory was historically common. But there’s a risk of overlooking other important factors by emphasizing grazing management as the main lever.

@RizomaSchool @Empty_America Much of soil carbon comes from root exudates too. Litter matters but it doesn’t persist long unless it is physically and chemically integrated with minerals. And mineral space is limited, leading to diminishing growth in persistent forms of carbon.

@RizomaSchool @Empty_America but in this system soil carbon is probably insensitive to grazing. 70 years of grazing vs no grazing and no difference in soil c.

@RizomaSchool @Empty_America soil carbon tends to decline beyond moderate stocking rates, regardless of animal density. and positive effects of grazing on plant production and soil organic matter are uncommon, especially in water-limited systems. rainfall is dammed or groundwater is pumped.

@Empty_America @RizomaSchool Unfortunately efforts to increase production often have unintended operational and ecological effects that are difficult to reverse. No guarantee that the fence will pay for itself

@johnafwendt @RizomaSchool Yeah everyone feels like there must be some way to "increase the stocking rate" but the system in question is basically the survivor of multiple ranch extinction events. It is what has persisted through the droughts, etc.

@RizomaSchool @Empty_America I’m not sure about the particular constraints for this producer but broadening spatial scale to hedge against local unpredictability can be adaptive. Rainfall is patchy and bison and pastoralists move around. Here we have the option to bring food to the cows too.

@RizomaSchool @Empty_America Intensification (eg cross-fencing) can be a trap in systems where the challenge is not to maximize production but to persist through resource bottlenecks (eg drought). Heterogeneity preserves adaption options.

@RizomaSchool @Empty_America Different grazing schemes have different effects in different situations. It can turn into a hammer and nail thing where you try to do it all with grazing while overlooking other historically important forms of disturbance like fire.