This 5 January 2019 video says about itself:
Pleistocene Park is a nature reserve on the Kolyma River south of Chersky in the Sakha Republic, Russia, in northeastern Siberia.
It is a 16 km2 (established in 1996) scientific nature reserve consisting of willow brush, grasslands, swamps, forests and a multitude of lakes. The average temperature in January is about –33 °C and in July +12 °C; annual precipitation is 200–250 mm.
The reserve is surrounded by a 600 km2 buffer zone that will be added to the park by the regional government once the animals have successfully established themselves. Pleistocene Park is owned and administered by a non-profit corporation, the Pleistocene Park Association.
An attempt is being made to recreate the northern subarctic steppe grassland ecosystem that flourished in the area during the last glacial period. The primary aim of Pleistocene Park is to recreate the mammoth steppe (ancient taiga/tundra grasslands that were widespread in the region during the last ice age).
The key concept is that animals, rather than climate, maintained that ecosystem. Reintroducing large herbivores to Siberia would then initiate a positive feedback loop promoting the reestablishment of grassland ecosystems. It will test the hypothesis that repopulating with large herbivores (and predators) can restore rich grasslands ecosystems, as expected if overhunting, and not climate change, was primarily responsible for the extinction of wildlife and the disappearance of the grasslands at the end of the Pleistocene epoch.
Here the hypothesis is that the change from tundra to grassland will result in a raised ratio of energy emission to energy absorption of the area, leading to less thawing of permafrost and thereby less emission of greenhouse gases. To study this, large herbivores have been released, and their effect on the local fauna is being monitored. Preliminary results point at the ecologically low-grade tundra biome being converted into a productive grassland biome, and at the energy emission of the area being raised.
This argument is the basis for rewilding Pleistocene Park’s landscape with megafauna that were previously abundant in the area, as evidenced by the fossil record. The grassland-steppe ecosystem that dominated Siberia during the Pleistocene disappeared 10,000 years ago and was replaced by a mossy and forested tundra and taiga ecosystem.