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The importance of grass
Traditional pastoral families in East Africa depend on livestock for their basic needs and the loss of a herd often means a descent into abject poverty - not just no milk or meat, but no money for clothes, schools or medicines and other food. Also, livestock reflects status, meaning that its loss can have devastating mental health impacts. It is no surprise, therefore, that grass is the currency of life in pastoral societies, wars are fought over access to it. In East Africa more grass means more livestock, and more livestock means more wealth, status and power.
Grasses are also important from a rangeland health perspective. They stabilise and protect soil, increase water absorption, add organic matter, sequester carbon and promote the growth of beneficial soil organisms. Bare earth is like a cancer on rangeland making it less able to trap and utilise the rain that does fall. Without grasses, rain water immediately runs-off the surface of the hard packed soil, washing it away into the gullies and rivers. Depleted soils can support less grass and less grass means less soil, and so the negative cycle continues. Without healthy grass cover, rangelands cease to function and pastoralist societies crumble. So why is this ‘bare earth’ cancer spreading in many of East Africa's rangelands? And what does the availability of grass have to do with lion conservation?
Historically, East Africa's rangelands have supported teeming herds of wildlife alongside livestock and people on traditional pastoral lands. The most famous East African rangeland, the Masai Mara - Serengeti ecosystem, is synonymous with a sea of grass as far as the eye can see, supporting heaving masses of wildebeest and zebra, alongside livestock in many areas. Livestock production and wildlife conservation are not mutually exclusive, even when it comes to large carnivores. Under the right conditions of plentiful wild prey combined with well protected livestock, large carnivores mostly leave livestock alone. Even with less than optimal conditions, pastoral land is still home to important lion populations today. But the incredible productivity of East Africa’s rangelands depends on management practices that support the growth of grasses.
Healthy rangeland can support masses of wildlife alongside livestock but the high productivity of East Africa’s rangeland is dependent on grass. Photo By Bruce Ludwig.
Where has the grass gone?
The depletion of grasses and creation of bare earth seems at first glance to be due to growing numbers of people and livestock, in combination with climate change resulting in less rainfall, less grass production and too many livestock dependent on it. Certainly climate change is exacerbating the situation, and ultimately there is a limit to the numbers of grazing animals that can be supported on any rangeland, but focusing entirely on numbers ignores an important part of the story; where this limit lies can be significantly influenced by the grazing management practices used.
When grass is not given respite to develop a strong root system, it gets plucked out of the soil creating large areas of bare earth, which eventually washes away to expose the rock beneath.
The management of grazing
Grasses have evolved to cope with heavy grazing and trampling pressure but they need periods of time where they can grow enough leaves to photosynthesise and generate the energy they need to grow strong root systems, and to flower and seed. Grasses that are grazed continuously photosynthesise less, have shallow and weakened roots and are eventually plucked completely out of the soil by grazing herds. This means that the key factor determining grass production is not how great the maximum grazing pressure is (number of animals) but rather whether the grasses have the time they need free from grazing pressure to grow leaves and photosynthesise (distribution of animals). Traditional pastoralism was historically nomadic, with herds joining together to follow the rain. Grazing wildlife species do the same to a greater or lesser degree. Larger compact herds putting greater pressure on a smaller area for a shorter time appear to be optimal for grass production. Compacted herds can also have the added benefit of breaking up soil surfaces and providing valuable manure, increasing the organic content for soil animals, which in turn increase the aeration of the soil and improve conditions for grasses to grow. Livestock production done in the right way can play an important role in the maintenance of healthy rangeland systems, however, issues around land ownership and access to other key resources like medical care and schooling have made pastoralist people and their herds more sedentary over time, and the synergy between livestock production, rangeland grasses and wider biodiversity is breaking down.
Large compacted herds graze, trample and fertilise grasslands intensively, leaving large areas of land to recover, unoccupied by livestock and accompanying people.
The grass-lion link
At Lion Landscapes, we are not rangeland management specialists but we do know what large carnivores need to persist into the future, and it is surprisingly similar to what grasses need too. Grazing systems that leave more of the rangeland free from livestock and accompanying people at any one time are also optimum for lions, and many other wildlife species. Lions are risk sensitive, and retaliatory or preventative killing by people protecting their livestock represents the biggest risk on the landscape. Human and livestock free areas that are being rested for grazing purposes therefore become an essential refuge for lions and other species that are sensitive to the presence of people, allowing them to rest, raise young, hunt and feed undisturbed, even during daylight hours. Additionally, larger compact herds are easier to guard from predation than livestock dotted about the landscape. Better protected livestock means less conflict between large carnivores and people over livestock predation, the biggest threat to the survival of large carnivore species in many areas.
Lions will only feel comfortable resting in the open during the daylight in areas where the rangeland is not occupied by livestock and accompanying herders. Photo by Taro Croze.
Lions and other large carnivores not only benefit from the spaces created between larger more compacted livestock herds, their presence also helps create them. The presence of large carnivores on the landscape significantly impacts space use by their prey and this extends to people and livestock too - where large carnivores are no longer a serious threat, herders can afford to be less vigilant, allow livestock to scatter and utilise with impunity habitats that would otherwise be viewed as having a higher predation risk. The presence of lions might even benefit grasses.
It is obvious that large carnivores need prey to eat, and more biodiverse and productive rangelands mean more prey, however, to say healthy grassland equals healthy lions and vice versa would be dangerously simplistic, there are many other factors at play in this complex story. However, understanding how to regenerate healthy biodiverse grasses and soils is a critical part of the puzzle, even for carnivore conservationists. The biggest challenge to doing this today, with traditional nomadic pastoralists becoming more sedentary, is possibly not rainfall (although a lack of rainfall is a challenge) or even livestock numbers (although there are ultimately limits to the numbers of livestock possible) but rather enabling and incentivising the creation of dynamic livestock free space on the landscape, such that on any given day, grasses, lions and other species have the space and time they need for refuge, recovery and regeneration.
Look out for our next blogs where we discuss the work being done to recreate the positive impacts of traditional pastoralism, and why Lion Friendly Livestock production is not just good for lions and other wildlife, but also grasses, soils, and ultimately livestock and people too.
We would like to thank the following donors, who have enabled the development of the Lion Friendly Livestock programme: The Darwin Initiative, Lion Recovery Fund, Tusk Trust and The Nature Conservancy. We would also like to thank our partners in this programme, Loisaba Conservancy, Borana Conservancy, True Range and Kyran Kunkel.
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