The study investigates ways to manage the mesic savanna ecosystem

The study investigates ways to manage the mesic savanna ecosystem

  • The dominance of native grasses is a land management issue in some savanna ecosystems, according to a study conducted in the Eastern Ghats.
  • Grass removal and fire exclusion were found to be the immediate solution to transitioning the region’s mid-savannah ecosystem to its historic state.
  • The study also emphasizes the importance of involving local communities in landscape management.

Study from the Eastern Ghats highlights indigenous dominance Cymbopogon Grass (lemongrass) in a mesic savanna ecosystem and explores the causes and control measures to return it to a desired or historical state to maintain biodiversity and ecosystem services.

Discussions about plant invasion and dominance are often in the context of foreign or alien species. However, the study shows that it is not uncommon for native grasses e.g Cymbopogon To control the landscape. The grass is unpalatable, and its dominance gives little room for other palatable grasses to grow and support livestock and herbivores.

Cymbopogon It is a C4 or warm season grass that needs plenty of sunlight and tolerates heat and fire. The grass contains oil, and the dominance of this flammable grass can lead to large, frequent fires that do not support biodiversity and the ecosystem.

The study, conducted by scientists from India and Germany, explored better land management strategies to control the grass.

Unique ecosystems affected by land use change

Natural open ecosystems such as savannas are unique ecosystems that harbor distinct biodiversity but are neglected as they are often viewed as degraded forests or seasonally dry tropical forests. The paper suggests that savanna ecosystems have existed in India for more than a million years, as fossil and molecular evidence from diverse and endemic C4 grasses suggests, predating any human modification of the landscape. They are highly vulnerable to various human pressures due to lack of protection.

A shepherd with his goat in the savanna landscape of Andhra Pradesh. According to the study, the high dominance of Cymbopogon grass here is likely explained by recent changes in land management. Photography by C.S. Sanesh.

The study was conducted in the savanna landscapes of Chittoor and Madanapalle in Andhra Pradesh where Cymbopogon Grass species are found to be dominant. High current control for Cymbopogon The grass is likely explained by recent changes in land management. The study indicates that before 1987, Cymbopogon The grass was harvested in the Eastern Ghats by local communities to cover the roofs of their huts with thatch. This periodic harvest combined with a fire control system largely controlled its growth and ensured the growth of palatable grasses for livestock to feed on. However, the grass harvest declined in the late 1980s, as brick and mortar houses replaced thatched huts. The newspaper indicates that the shepherds remember this Cymbopogon Grass was sparser in the landscape and palatable fodder for livestock was more abundant.

The study also indicates an increase in the local population and a similar growth in livestock but largely sheep and goats that do not consume this grass. “These species are usually eaten only by large-bodied grazers like gaurs and cattle, and that too when they (the herbivores) are young,” said Jayashree Ratnam, director of the Wildlife Biology and Conservation Program at the National Center for Biological Sciences, who has studied savanna ecosystems on Earth. Wide range: “As adults, their leaves become unpalatable even to coarse macronutrients.”

The study explored three different management strategies – controlling both Cymbopogon Herbs and fire. Fire Exclusion, Manual Weed Removal, and Fire Exclusion – They found that weed removal and fire exclusion are necessary to reduce dominant weeds to achieve significant growth in palatable herbaceous plant biomass and species diversity.

Fire control as a land management strategy

Fire is an integral part of savanna management. Unlike humid ecosystems, where moisture degrades biomass, dry ecosystems such as savannas rely on fire to recycle biomass. “Most of the annual rainfall that falls on these areas is about 500 mm. Rainfall is also irregular. There is not enough rain to decompose the biomass. So fire is an integral part of the system,” said study author CS Sanesh. Fire management is critical in these ecosystems as optimal fire regimes promote healthy grass-dominated communities and the species that depend on them.

A shepherdess takes her goats to graze. Fire plays an essential role in managing the dominance of some weeds in dry areas. Photography by C.S. Sanesh.

The paper calls for excluding fire for ideal periods, which is not the case now. “We found that the fire return interval was every 1.7 years. “In some of my study areas, two fires occurred within one year, which is not ideal,” he said. The key finding, according to Sanesh, is that if the dominant grass is removed while fire is excluded for After a year and a half or two, palatable grass increases to about 90%. However, in the long term, fires need to be part of savanna management. The paper suggests that perhaps the best management going forward is to restore the historic fire regime.

The study also underscores the role local communities can play in monitoring grass dominance. Sanesh says he believes in landscape management by local communities through government initiatives such as the Mahatma Gandhi National Rural Employment Guarantee Act (MNREGA).

Ratnam points out that community management of these ecosystems is important and can be done through a combination of harvesting, controlled burning and grazing by livestock, depending on the condition of the landscape.

Banner image: An aerial view of a savanna landscape with an overgrowth of Cymbopogon grass. Photography by C.S. Sanesh.

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