In Wrangel Island it is very cold but mammoths managed to live here because they managed their pastures themselves. In cold or dry climate decomposition can be very slow, but in Pleistocene ecosystems decomposition was independent form climate because in a mammoth stomach temperature is around 36 C all year round.
In the 1930s Gorodkov estimated Wrangel Island could support 300-400 reindeers. In 20000, the number renderer exceeded 16,000 and mud ox 1000. By far the high biomass of all Russian national parks, in the coldest climate
Estimated mammoth density in Pleistocene was 1 mammoth per square km, 5 bison, 15 reindeer, 6 horses. Total biomass around 10 t/km2
In Pleistocene park in winter only excrement covers the soil. Recycling of plant matter is rapid. Introduced animals converted boggy wetland to dry meadow. Horses, bison and musk-ox plus three species of deer.
Mammoth biome was the biggest biome of our planet. Walter et al (2006)
Various pictures show how adding grazing causes grasses to appear, covering bare soils. Grasses have co-evolved with herbivores, Grasses grow only with herbivores.
Photos of national park in Netherlands. Deer in forest kill one tree per day.
What is the total biomass of megafauna in our planet before humans expanded? Use methane as a proxy of megafauna biomass. In Pleistoce methane production from herbivores estimated to be 100 Tg methane per year.
Prior to appearance of grasslands around 20 million years, plants responded t herbivory through chemical defences, decomposition and recycling were slow. Then with grasslands a new animal-vegetation symbiosis appeared, with rapid recyclng that maintained high animal biomass systems.
Humans knocked out half of this symbiosis (the megafauna), caused grasses to retreat into forests. Humans lost their traditional food source, but this opened the way for artificial grasslands (farmlands and pastures). Our cattle and horses are Pleistocene fauna. But even now we have not reached the biomass of animal biomass in the Pleistocene.
He suggests that Pleistocene predators shepherd “their” herds in a similar way to You don’t need brains to maintain herds - leaf cutter ants could do this. Dogs can maintain herds from their genomic memory.
He has a new rewilding park experiment south of Moscow. He advocates new rewilding experiments in fertile regions with good climate, in contrast to current national parks.