Pastures in Zeku are suffering because of the combination of annual grazing and poisoning of grassland rodents (mostly zokors and pika). The situation could be reformed by returning to a system of grazing neighboring herds together on healthy grasslands instead of grazing each family's herds individually on "private" grassland, indiscriminate of the grassland's health; letting grassland rest every once in a while for an entire year; ceasing the poisoning and removal of pika and zokors; increasing the diversity of herds; and assisting with the seeding of new grass when necessary.
In the winter pasture of the village of Nor mGo, Zeku, nomads used to keep horses, yaks, sheep, and perhaps goats and combine the herds of various families together while they grazed. They would take their herds wherever the grass was healthy and plentiful. These days, the winter pasture is divided into plots of land that are leased out by their "owners" every year if the "owners" don't need them for their own herds. The economic incentive is to rent out the land every year (otherwise, it would provide no income). Moreover, because the grasslands are degrading more or less uniformly across pastures in the village, although an individual's grassland quality decreases over time, he receives the same price for it year after year because of a lack of healthy competition. Therefore, there is currently no incentive to let a pasture rest; whereas, before, if a grassland was degrading in quality, no nomads would choose to have their yaks graze on it that year, thereby letting it recover. In the summer pasture, the old method is still used, leading to relative high quality of the summer grasslands.
Furthermore, whereas pika and zokors would usually contribute to grassland succession on degraded grassland; these days, when they move into degraded winter pastures (degraded for the reason described in the last paragraph), they are unwelcome because pika are known to eat grass and zokors are known to obscure it with their molehills; both of which are seen to reduce the amount of grass available for grazing yaks. Since the pastures are no longer allowed to rest (for the reasons described in the last paragraph), zokors and pika are therefore detested for moving into the winter pastures and then poisoned or trapped as possible, thereby retarding grassland succession, with the consequences of reducing the seed bank and variety of grasses available on winter pastures. [Notes: pika poison is common. Zokor poison is not. The dirt of the Nor mGo zokors' hills is rapidly covered with new grasses, since the zokor hill soil is so fresh and nutritious.]
The pastures that are most valued in Nor mGo have these qualities: in the winter pasture, "Na" is valued: a "hard" grassland with many knobby hills and lots of water that is hard for rodents to burrow into and has plenty of grass, even at the end of spring. Large, flat expanses of grass are valued in summer pastures. Pastures that receive lots of sun are highly valued, for it is on those that snow melts quickly. Finally, it should be noted that yaks are most comfortable on slopes, choosing not to move often once arriving on a slope (whereas goats or sheep would graze anywhere). I wonder if the "Na" grasslands actually began as grassland with many zokor hills, and if those zokor hills are where the "knobs" came from before they were covered with new grass.
Only one family from Nor mGo still keeps goats, although many used to; the change of which may pose a threat to the diversity of grass species on the grassland over time.
Under certain circumstances, where the seed bank of a grassland has been severely depleted, assistance by nomads with new seeding of local grasses may help it to recover more quickly.