- After past efforts to afforest grasslands, there are now growing calls to restore and improve them by planting grasses.
- Grassland ‘improvement’ is rooted in the idea that grasslands are formed via forest degradation and that they are unproductive ecosystems. The ecological and evolutionary history of India’s grasslands makes it clear that these are in fact ancient and productive ecosystems that do not need to be improved.
- We need to invest more in the science of restoration. At this time, restoring Indian grasslands via grass plantation programmes is neither an ecologically and economically sound approach nor a socially just one, write the authors of this commentary.
- The views in the commentary are that of the authors.
For a long time, India’s grasslands and savannahs were not considered important ecosystems for biodiversity conservation. Fortunately, this picture is slowly changing, even though a large proportion of the country’s grasslands continue to be considered “wastelands”. Interest in documenting grassland biodiversity has skyrocketed of late – social media today is replete with stunning images of wolves, hyenas, and foxes from Indian grasslands. Policymakers are also recognising the value of grasslands by declaring new conservation reserves and recognising negative effects of tree plantations.
As people start to realise the downside of planting trees on grasslands, they are now turning to planting grasses. In recent times Gujarat and Maharashtra — states that have historically had large areas of grassland — have seen a renewed push by the respective state governments to restore grasslands. In Gujarat, the state government’s grass development project aims to remove the invasive tree, Prosopis juliflora, and restore 20,000 hectares (ha) of grassland in Kutch. In Maharashtra, there is a proposal to restore about 33,200 ha of grassland under the state government’s Forest Meadow and Fodder Area Development Program. Both initiatives are underlain by the aim to provide forage for wild herbivores, increase biodiversity and increase fodder for livestock, thereby also supporting livelihoods of agro-pastoralists. As part of these restoration efforts, exotic trees planted in an earlier time are being removed. This is followed by ploughing, fertilising, and planting of ‘improved’ grass varieties by the government and nature enthusiasts. However, implicit in these restoration efforts are two fundamental misconceptions about grasslands. One is that they are degraded. The other, that they are unproductive. These misconceptions lead to the assumption that grasslands need to be ‘improved’, and therein lies the problem.
Ecological history tells us that grasslands are not degraded forests
There is longstanding confusion among botanists, ecologists and policymakers about the origin of India’s grasslands. The outdated idea that grasslands are degraded and mere intermediate stages towards forests is being increasingly challenged by emerging research that points towards their ancient origins. Fossil pollen data from several grasslands and savannahs in India reveals that these were open-canopy tree-grass mixtures for thousands of years. This data shows that the gradual drying and development of a more seasonal climate in the subcontinent from 4 million years ago, and not recent forest cutting by humans, has shaped the origins of Indian grasslands. One recent study, in fact, suggests that the natural formation of grasslands and savannas in India attracted and led to spread of agro-pastoralism in the Deccan peninsula, rather than grasslands being the result of people cutting down forests to farm and settle. Apart from fossils, the presence and evolutionary origins of plants and animals endemic to Indian grasslands validate that these ecosystems are ancient and not anthropogenic, and do not warrant large-scale improvement.
Grasslands are productive, and disturbing soil hampers functioning of grasslands
Across the dry tropics, grasslands exist within a climatic envelope that is hot, dry and seasonal. The fossil record bears this out, with the global spread of tropical grasslands coinciding with the appearance of hot, dry environments. This period coincided with the evolution of specialist C4 grasses – a physiological adaptation to maintain high productivity even in hot, dry conditions. This set of climatic conditions results in open grassy systems with scattered trees, with rainfall, fire, and grazing as key drivers. Thus, these grasses have evolved uniquely to deal with low and variable rainfall, and to maintain high productivity. They respond rapidly to the onset of rains, dying down during the dry season. Both wildlife and livestock have adapted to cope with this variability in resources, a well-known example of this being the annual migration of large herds of wildebeest between the Serengeti and the Mara in Africa, tracking rainfall and the wave of grassland productivity that follows. Nomadic pastoralism is a similar adaptation to spatial and temporal resource variability.
Another unique adaptation of grasses is that grazing enhances productivity. In the absence of grazing, productivity stagnates. The sight of heavily grazed or dry grasslands have encouraged the misconception about them being unproductive. But to think that grassland productivity can be enhanced by ploughing and fertilising, or by planting ‘improved’ varieties of grasses is an agricultural perspective. These are wasted inputs in the absence of other subsidies provided to agricultural systems. Grassland productivity is driven by rainfall, not by the absence of soil fertility or the need for ‘improved grass varieties’. And these misplaced interventions are likely to do more damage than good, by destroying soil structure, reducing below-ground repositories of soil carbon, and destroying the bud banks of perennial grasses and other vegetation that help grasslands regeneration during monsoon.
Grasses are not the major contributors of grassland biodiversity
One goal of ecological restoration is to typically increase biodiversity. Most grassland restoration practitioners therefore focus on adding grasses to bring back lost grassland diversity. But, what kinds of plants contribute most to grassland diversity? One may intuitively think the answer is grasses. But contrary to this belief, while grasses certainly are the most abundant group in grasslands, it is the non-grasses that actually contribute to most of the biodiversity. For example, only at most 4 out of every 10 plant species are grasses in Maharashtra’s Saswad grasslands. The bulk of the plant species are non-grasses or ‘forbs’: herbs with pretty flowers. Complicating matters further, grasses and forbs compete for resources. So if a grassland patch is grass-dominated, forbs find it hard to grow and vice versa. This then calls into question the overly simplistic approach of planting only grasses that can in fact decrease biodiversity.
Restoring grasslands is a complex challenge
We know little about the science of restoration to be able to actually practice ecologically, economically and socially feasible grassland restoration. There are several towering knowledge gaps in front of us. First, we barely know what kind of reference plant composition we are aiming for. An accurate understanding of reference ecosystem states is a central principle of sound ecological restoration. Second, there are no studies from India that recommend large scale grass seeding for grassland restoration. In their pioneering study on India’s grassland plant diversity, Dabadghao & Shankarnarayan (1973) wrote “The reseeding of pastures following ploughing, soil preparation and the application of fertilizers, the normal method of producing improved pastures in humid temperate and other environments, is of doubtful application in India,” going on to say, “pasture reseeding on anything other than an experimental scale has not yet been shown to be a practicable proposition in India”. Unfortunately, the situation has changed little since then. Even if we achieve success in re-seeding native grassland biodiversity in experimental plots, scaling up such efforts is likely to be impossible today given the huge amounts of seeds required (about 10 kg per hectare), and the lack of knowledge on mass propagation of native grasses and forbs. Third, grassland restoration is very costly. The Gujarat and Maharashtra governments are planning to spend crores of taxpayers’ rupees on activities that instead of benefitting grasslands, will very likely destroy them. Allocating even a small fraction of that amount for regional experimental studies to design scientifically sound and replicable restoration solutions would be a more judicious investment. Finally, current policies exclude the Maldhari and Dhangar pastoralists, key stakeholders of grassland restoration, who have been grazing livestock on these grasslands for centuries. Including their traditional knowledge in grassland management will certainly benefit biodiversity and local livelihoods.
Towards achieving a shared vision of conserving Indian grasslands, we urge managers and the public to not implement restoration programmes that involve planting improved grass varieties and disturbing soil. However well-intentioned these initiatives might be, there is barely any evidence to suggest their efficacy. Instead, investing in the science of restoration will lead to the sustainable conservation and restoration of India’s grasslands.
First Published by Mongabay on 8 August 2022